Systemic Sclerosis and Related Disorders
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Questions and Answers

What is a prototype of limited type scleroderma?

  • Mixed connective tissue disease
  • Lupus erythematosus
  • Rheumatoid arthritis
  • CREST syndrome (correct)

    • Which organ is commonly involved in diffuse type scleroderma?

  • Skin
  • Heart
  • Lungs (correct)
  • Liver

    • Which of the following is highly associated with diffuse type scleroderma?

  • Anti-Centromere antibodies
  • Anti-DNA antibodies
  • Antinuclear antibodies (ANA)
  • Anti-Scl-70 antibodies (correct)

    • What is the primary initial step in the wound healing process?

    <p>Inflammation</p> Signup and view all the answers

    Which of the following best describes labile tissues?

    <p>They possess stem cells that continuously cycle</p> Signup and view all the answers

    What characterizes mixed connective tissue disease?

    <p>Features of scleroderma, lupus, and polymyositis</p> Signup and view all the answers

    Which type of tissue is characterized as permanent and cannot regenerate?

    <p>Cardiac muscle</p> Signup and view all the answers

    What common symptom might a patient with scleroderma experience in the GI tract?

    <p>Esophageal dysmotility</p> Signup and view all the answers

    What is the main characteristic of stable tissues regarding their cell cycle?

    <p>They are quiescent but can reenter the cell cycle when needed.</p> Signup and view all the answers

    Which of the following tissues demonstrates the least regenerative potential?

    <p>Myocardium</p> Signup and view all the answers

    What is the primary component of granulation tissue during the initial phase of repair?

    <p>Type III collagen</p> Signup and view all the answers

    Which type of collagen replaces type III collagen during scar formation?

    <p>Type I collagen</p> Signup and view all the answers

    What triggers the repair process when regenerative stem cells are lost?

    <p>Formation of granulation tissue.</p> Signup and view all the answers

    Which statement about collagenase is correct?

    <p>It removes type III collagen from tissues.</p> Signup and view all the answers

    Which factor is primarily involved in mediating tissue regeneration and repair through signaling?

    <p>Paracrine signaling via growth factors.</p> Signup and view all the answers

    What role do myofibroblasts play in the healing process?

    <p>They contract and help reduce the wound size.</p> Signup and view all the answers

    Which growth factor is known for its role in angiogenesis?

    <p>Vascular endothelial growth factor (VEGF)</p> Signup and view all the answers

    What characterizes a keloid compared to a hypertrophic scar?

    <p>Out of proportion with the original wound</p> Signup and view all the answers

    Which vitamin is essential for the hydroxylation of proline and lysine in collagen synthesis?

    <p>Vitamin C</p> Signup and view all the answers

    Primary intention in wound healing is defined as:

    <p>Wound edges approximated</p> Signup and view all the answers

    Which factor is NOT a common cause of delayed wound healing?

    <p>Correct suturing technique</p> Signup and view all the answers

    What is a defining feature of hypertrophic scars?

    <p>Localized to the site of the original injury</p> Signup and view all the answers

    Which deficiency is associated with impaired collagen cross-linking?

    <p>Copper deficiency</p> Signup and view all the answers

    What condition is described as the rupture of a wound, particularly noted after abdominal surgery?

    <p>Dehiscence</p> Signup and view all the answers

    Stable tissues are comprised of cells that are continually proliferating to regenerate tissue.

    <p>False</p> Signup and view all the answers

    Type I collagen is primarily found in embryonic tissue and keloids.

    <p>False</p> Signup and view all the answers

    Permanent tissues have a significant capacity for regeneration.

    <p>False</p> Signup and view all the answers

    Myofibroblasts play a key role in the contraction of wounds during the healing process.

    <p>True</p> Signup and view all the answers

    Granulation tissue formation is the initial phase of tissue repair and consists mainly of adipocytes.

    <p>False</p> Signup and view all the answers

    Hematopoietic stem cells are located in the skin's basal layer.

    <p>False</p> Signup and view all the answers

    Macrophages secrete growth factors that have a paracrine signaling role in tissue regeneration and repair.

    <p>True</p> Signup and view all the answers

    Collagenase is an enzyme that promotes the formation of type III collagen.

    <p>False</p> Signup and view all the answers

    TGF-α primarily acts as a growth factor for endothelial cells and fibroblasts.

    <p>True</p> Signup and view all the answers

    Vitamin C plays no significant role in collagen synthesis.

    <p>False</p> Signup and view all the answers

    Keloids are characterized by a deficiency in type III collagen.

    <p>False</p> Signup and view all the answers

    Delayed wound healing can be caused by factors like diabetes and malnutrition.

    <p>True</p> Signup and view all the answers

    Hypertrophic scars are typically out of proportion to the original wound size.

    <p>False</p> Signup and view all the answers

    Platelet-derived growth factor is exclusively involved in the regulation of fibroblast growth.

    <p>False</p> Signup and view all the answers

    Secondary intention healing involves bringing wound edges together.

    <p>False</p> Signup and view all the answers

    Copper is important for stabilizing collagen by functioning as a cofactor for lysyl oxidase.

    <p>True</p> Signup and view all the answers

    Diffuse type scleroderma is characterized by early visceral involvement and affects any organ.

    <p>True</p> Signup and view all the answers

    Labile tissues have a low regenerative capacity due to their limited stem cell presence.

    <p>False</p> Signup and view all the answers

    The presence of anti-Centromere antibodies is indicative of the diffuse type of scleroderma.

    <p>False</p> Signup and view all the answers

    Regeneration in wound healing is primarily the replacement of damaged tissue with non-native tissue.

    <p>False</p> Signup and view all the answers

    Mixed connective tissue disease features characteristics of systemic sclerosis, SLE, and rheumatoid arthritis.

    <p>False</p> Signup and view all the answers

    Granulation tissue formation involves the initial phase dominated by collagen type III.

    <p>True</p> Signup and view all the answers

    Stable tissues regenerate rapidly after an injury due to their rich supply of stem cells.

    <p>False</p> Signup and view all the answers

    The repair process is initiated when regeneration fails and the tissue utilizes myofibroblasts.

    <p>True</p> Signup and view all the answers

    What is the role of growth factors released by macrophages during tissue repair?

    <p>They facilitate paracrine signaling that targets and stimulates fibroblasts in tissue regeneration.</p> Signup and view all the answers

    Explain the significance of collagen type III in granulation tissue.

    <p>Collagen type III provides pliability in granulation tissue, allowing initial tissue repair before being replaced by type I collagen.</p> Signup and view all the answers

    How do stable tissues react after an injury compared to permanent tissues?

    <p>Stable tissues can re-enter the cell cycle to regenerate, whereas permanent tissues have limited regenerative capacity.</p> Signup and view all the answers

    What is granulation tissue and what are its main cellular components?

    <p>Granulation tissue is the initial healing tissue formed during repair, composed of fibroblasts, capillaries, and myofibroblasts.</p> Signup and view all the answers

    What is the role of myofibroblasts in the wound healing process?

    <p>Myofibroblasts contract the wound to promote closure and stabilize tissue during repair.</p> Signup and view all the answers

    Describe the transition from granulation tissue to scar formation.

    <p>Initially, type III collagen in granulation tissue is gradually replaced by type I collagen, strengthening the scar.</p> Signup and view all the answers

    What happens to hepatocytes after partial liver resection?

    <p>Hepatocytes undergo compensatory hyperplasia, proliferating to restore liver mass, then return to quiescence.</p> Signup and view all the answers

    Why is type I collagen important in the context of tissue repair?

    <p>Type I collagen has high tensile strength, providing durability and support to healed tissues.</p> Signup and view all the answers

    What are the main features that differentiate keloids from hypertrophic scars?

    <p>Keloids exhibit excessive scar tissue that is disproportionate to the original wound and are characterized by an abundance of type III collagen, while hypertrophic scars are localized and generally do not extend beyond the wound edges.</p> Signup and view all the answers

    Explain the role of Vitamin C in wound healing.

    <p>Vitamin C is a crucial cofactor for the hydroxylation of proline and lysine in procollagen, which is necessary for collagen cross-linking and stabilization.</p> Signup and view all the answers

    How does TGF-β contribute to wound healing?

    <p>TGF-β acts as a fibroblast growth factor, promoting fibroblast proliferation and collagen deposition while also inhibiting inflammation.</p> Signup and view all the answers

    What is the significance of myofibroblasts in the healing process?

    <p>Myofibroblasts are critical for wound contraction, helping to reduce the size of the wound by pulling the edges together during the healing process.</p> Signup and view all the answers

    Identify the primary mechanisms leading to delayed wound healing.

    <p>Delayed wound healing can result from infection, nutritional deficiencies, such as Vitamin C, copper, and zinc, as well as conditions like diabetes and ischemia.</p> Signup and view all the answers

    What distinguishes primary intention healing from secondary intention healing?

    <p>Primary intention healing involves the direct approximation of wound edges, often through suturing, resulting in minimal scarring, while secondary intention healing occurs when the edges are not approximated and granulation tissue fills the defect.</p> Signup and view all the answers

    Discuss the importance of vascular endothelial growth factor (VEGF) in tissue repair.

    <p>VEGF is essential for angiogenesis, facilitating the formation of new blood vessels, which supply oxygen and nutrients necessary for tissue repair and regeneration.</p> Signup and view all the answers

    How does copper contribute to collagen stability during wound healing?

    <p>Copper serves as a cofactor for lysyl oxidase, which cross-links lysine and hydroxylysine residues in collagen, promoting its stability and strength.</p> Signup and view all the answers

    What is the significance of anti-Scl-70 antibodies in diffuse type scleroderma?

    <p>Anti-Scl-70 antibodies are highly associated with diffuse type scleroderma, indicating a likelihood of widespread organ involvement.</p> Signup and view all the answers

    How does the regenerative capacity of labile tissues impact wound healing?

    <p>Labile tissues have a high regenerative capacity due to the presence of stem cells that continuously renew themselves.</p> Signup and view all the answers

    In wound healing, what role does the combination of regeneration and repair play?

    <p>The combination allows for the restoration of tissue integrity through both the natural replacement of cells and the formation of scar tissue.</p> Signup and view all the answers

    Describe the primary characteristics distinguishing CREST syndrome from diffuse scleroderma.

    <p>CREST syndrome features limited skin involvement and late visceral symptoms, while diffuse scleroderma presents with extensive skin changes and early visceral organ involvement.</p> Signup and view all the answers

    What role do myofibroblasts play in the context of wound contraction during healing?

    <p>Myofibroblasts facilitate the contraction of wound edges, promoting closure and reducing the size of the wound.</p> Signup and view all the answers

    How is the factor of esophageal dysmotility relevant in the context of scleroderma?

    <p>Esophageal dysmotility is a common complication in scleroderma that occurs due to smooth muscle involvement, leading to swallowing difficulties.</p> Signup and view all the answers

    What distinguishes mixed connective tissue disease from other connective tissue disorders?

    <p>Mixed connective tissue disease is characterized by a unique combination of features from systemic lupus erythematosus, systemic sclerosis, and polymyositis.</p> Signup and view all the answers

    Explain the importance of angiogenesis in the wound healing process.

    <p>Angiogenesis is crucial for providing oxygen and nutrients to the healing tissue, facilitating repair and regeneration.</p> Signup and view all the answers

    Interaction of growth factors with receptors results in gene expression and cellular ______.

    <p>growth</p> Signup and view all the answers

    Delayed wound healing can occur due to infection, vitamin C deficiency, or ______.

    <p>diabetes</p> Signup and view all the answers

    Myofibroblasts contribute to wound healing by ______ the wound to minimize size.

    <p>contracting</p> Signup and view all the answers

    Platelet-derived growth factor is important for the growth of ______, smooth muscle, and fibroblasts.

    <p>endothelium</p> Signup and view all the answers

    Keloids are characterized by excess type ______ collagen production.

    <p>III</p> Signup and view all the answers

    Primary intention healing leads to minimal ______ formation.

    <p>scar</p> Signup and view all the answers

    TGF-β is an important fibroblast growth factor that also inhibits ______.

    <p>inflammation</p> Signup and view all the answers

    Vitamin C is crucial for the hydroxylation of ______ and lysine in collagen synthesis.

    <p>proline</p> Signup and view all the answers

    The ___ type of scleroderma is characterized by limited skin involvement, primarily affecting the hands and face.

    <p>limited</p> Signup and view all the answers

    In diffuse scleroderma, _____ involvement occurs early, and any organ can potentially be affected.

    <p>visceral</p> Signup and view all the answers

    Mixed connective tissue disease is characterized by the presence of antibodies to ___ ribonucleoprotein.

    <p>U1</p> Signup and view all the answers

    Healing begins when ___ occurs, which is the body's response to injury.

    <p>inflammation</p> Signup and view all the answers

    Labile tissues possess ___ cells that continuously cycle to regenerate the tissue.

    <p>stem</p> Signup and view all the answers

    The initial phase of granulation tissue formation involves the dominant presence of collagen type ___.

    <p>III</p> Signup and view all the answers

    In stable tissues, cells have a limited ability to proliferate, but can do so in response to ___.

    <p>injury</p> Signup and view all the answers

    The repair process of tissue healing utilizes ___ when regenerative stem cells are lost.

    <p>myofibroblasts</p> Signup and view all the answers

    Stable tissues are comprised of cells that are ______, but can reenter the cell cycle to regenerate tissue when necessary.

    <p>quiescent</p> Signup and view all the answers

    Permanent tissues lack significant regenerative potential, such as ______, skeletal muscle, and neurons.

    <p>myocardium</p> Signup and view all the answers

    Granulation tissue consists of fibroblasts, capillaries, and ______ that help contract the wound.

    <p>myofibroblasts</p> Signup and view all the answers

    Type III collagen is pliable and present in ______, embryonic tissue, and keloids.

    <p>granulation tissue</p> Signup and view all the answers

    Collagenase removes type III collagen and requires ______ as a cofactor.

    <p>zinc</p> Signup and view all the answers

    The initial phase of repair involves the formation of ______ tissue.

    <p>granulation</p> Signup and view all the answers

    Deep skin cuts typically trigger the repair process where ______ stem cells are lost.

    <p>regenerative</p> Signup and view all the answers

    Type I collagen has high tensile strength and is present in ______, bone, tendons, and most organs.

    <p>skin</p> Signup and view all the answers

    Match the following tissues with their characteristics:

    <p>Small and large bowel = Contain stem cells in mucosal crypts Skin = Contains stem cells in the basal layer Bone marrow = Contains hematopoietic stem cells Permanent tissues = Lack significant regenerative potential</p> Signup and view all the answers

    Match the types of healing with their definitions:

    <p>Primary intention = Wound edges are brought together Secondary intention = Healing occurs by granulation tissue formation Repair = Replacement of damaged tissue with fibrous scar Compensatory hyperplasia = Regeneration of liver after partial resection</p> Signup and view all the answers

    Match the types of collagen with their locations or characteristics:

    <p>Type I collagen = High tensile strength, present in skin and bone Type III collagen = Pliable, found in granulation tissue and keloids Collagenase = Enzyme that degrades type III collagen Type III collagen in embryonic tissue = Present in developing tissues and uterus</p> Signup and view all the answers

    Match the healing processes with their triggers:

    <p>Granulation tissue formation = Initial phase of repair after tissue injury Scar formation = Replacement of type III collagen with type I collagen Mediated repair = Paracrine signaling via growth factors Inflammation = Promotes recruitment of healing cells to the injury site</p> Signup and view all the answers

    Match the features of fibroblasts and myofibroblasts with their roles:

    <p>Fibroblasts = Deposit type III collagen in granulation tissue Myofibroblasts = Contract the wound to facilitate closure Fibroblasts in scarring = Transition to produce type I collagen Myofibroblasts in inflammation = Secrete growth factors to aid repair</p> Signup and view all the answers

    Match the statement about stem cells with the correct type of tissue:

    <p>Mucosal crypts in bowel = Contain stem cells for regeneration Basal layer in skin = Contains stem cells for epithelial renewal Bone marrow = Source of hematopoietic stem cells Permanent tissues = Do not contain significant regenerative stem cells</p> Signup and view all the answers

    Match the following repair mechanisms with their descriptions:

    <p>Paracrine signaling = Facilitates interaction between macrophages and fibroblasts Granulation tissue = Composed of fibroblasts and capillaries Collagen Type III = First collagen laid down in repair processes Collagen Type I = Replaces type III during later stages of repair</p> Signup and view all the answers

    Match the factors responsible for tissue regeneration and repair with their roles:

    <p>Growth factors = Secreted by macrophages to target fibroblasts Zinc = Cofactor required for collagenase function Type III collagen = Presents special characteristics for granulation tissue Myofibroblasts = Key players in wound contraction</p> Signup and view all the answers

    Match the following types of scleroderma with their characteristics:

    <p>Limited type = Skin involvement is limited to hands and face Diffuse type = Early visceral involvement of any organ CREST syndrome = Prototype of limited type scleroderma Anti-Scl-70 antibodies = Highly associated with diffuse type scleroderma</p> Signup and view all the answers

    Match the following wounds healing strategies with their descriptions:

    <p>Primary intention = Bringing wound edges together Secondary intention = Healing without approximating wound edges Granulation tissue formation = Initial phase dominated by type III collagen Healing by regeneration = Replacement of damaged tissue with native tissue</p> Signup and view all the answers

    Match the following types of tissues with their regenerative capacity:

    <p>Labile tissues = Contain stem cells that continuously cycle Stable tissues = Regenerate only when needed Permanent tissues = Demonstrate little to no regeneration capacity Regenerative capacity = Categorizes tissues based on recovery potential</p> Signup and view all the answers

    Match the following factors with their roles in wound healing:

    <p>Myofibroblasts = Play a key role in contraction of wounds TGF-α = Act as a growth factor for fibroblasts Collagen type III = Major component of granulation tissue Macrophages = Secrete growth factors for paracrine signaling</p> Signup and view all the answers

    Match the following symptoms with the associated organs in diffuse type scleroderma:

    <p>Raynaud phenomenon = Vessels Esophageal dysmotility = GI tract Interstitial fibrosis = Lungs Scleroderma renal crisis = Kidneys</p> Signup and view all the answers

    Match the following autoimmune diseases with their associated features:

    <p>Systemic lupus erythematosus (SLE) = Characterized by a wide range of symptoms Polymyositis = Involves inflammation of muscle tissues Mixed connective tissue disease = Combines features of multiple autoimmune disorders Systemic sclerosis = Involves skin thickening and organ involvement</p> Signup and view all the answers

    Match the following terms regarding collagen in wounds with their definitions:

    <p>Hydroxylation of proline = Essential for collagen synthesis Type I collagen = Mostly found in mature scars Type III collagen = Major component of early healing granulation tissue Collagen cross-linking = Stabilizes the collagen structure post synthesis</p> Signup and view all the answers

    Match the different types of antibodies with the conditions they are associated with:

    <p>Anti-Centromere antibodies = Indicative of limited type scleroderma U1 ribonucleoprotein antibodies = Characteristic of mixed connective tissue disease Anti-Scl-70 antibodies = Linked to diffuse type scleroderma ANA (antinuclear antibodies) = Commonly present in autoimmune diseases</p> Signup and view all the answers

    Match the growth factors with their respective functions:

    <p>TGF-α = Epithelial and fibroblast growth factor TGF-β = Inhibits inflammation Platelet-derived growth factor = Growth factor for smooth muscle Vascular endothelial growth factor (VEGF) = Mediates angiogenesis</p> Signup and view all the answers

    Match the wound healing intentions with their characteristics:

    <p>Primary intention = Wound edges brought together Secondary intention = Granulation tissue fills the defect Delayed wound healing = Most commonly caused by infection Dehiscence = Rupture of a wound after surgery</p> Signup and view all the answers

    Match the nutrient deficiencies with their effects on wound healing:

    <p>Vitamin C = Impaired hydroxylation of proline and lysine Copper = Deficiency in collagen cross-linking Zinc = Inhibits collagenase function Iron = Not typically associated with collagen synthesis</p> Signup and view all the answers

    Match the types of scars with their characteristics:

    <p>Hypertrophic scar = Localized excess scar tissue Keloid = Excess scar tissue out of proportion to the wound Normal scar = Collagen primarily type I Granulation tissue = Predominantly consists of type III collagen</p> Signup and view all the answers

    Match the growth factors with their tissue types affected:

    <p>TGF-α = Epithelial cells FGF = Bone and skeletal development VEGF = Endothelial cells PDGF = Fibroblasts and smooth muscle</p> Signup and view all the answers

    Match the causes of delayed wound healing with their descriptions:

    <p>Infection = Most common cause of delayed healing Vitamin C deficiency = Affects collagen formation Diabetes = Impairs blood supply and healing Foreign body = Inhibits normal healing processes</p> Signup and view all the answers

    Match the growth factors with their primary roles in wound healing:

    <p>TGF-β = Promotes fibroblast proliferation VEGF = Stimulates angiogenesis PDGF = Encourages fibroblast migration FGF = Enhances keratinocyte proliferation</p> Signup and view all the answers

    Match the descriptions with the healing outcomes:

    <p>Primary intention healing = Minimal scar formation Secondary intention healing = Myofibroblasts contract the wound Keloid formation = Excess type III collagen Hypertrophic scar = Localized production of scar tissue</p> Signup and view all the answers

    Study Notes

    Systemic Sclerosis

    • Characterized by thickening and tightening of the skin
    • Classified into two types: limited and diffuse
    • Limited Type:
      • Only affects hands and face in the beginning, with later involvement of internal organs
      • Prototypical example is CREST syndrome (Calcinosis, Raynaud phenomenon, Esophageal dysmotility, Sclerodactyly, and Telangiectasias)
    • Diffuse Type
      • Affects skin broadly with early involvement of internal organs
      • Commonly affected organs include vessels, GI tract, Lungs, and kidneys
      • Strongly associated with antibodies to DNA topoisomerase I (anti-Scl-70)

    Mixed Connective Tissue Disease

    • Autoimmune disorder with mixed features of Systemic Lupus Erythematosus (SLE), Systemic Sclerosis, and Polymyositis
    • Characterized by the presence of Antinuclear Antibody (ANA) along with serum antibodies to U1 Ribonucleoprotein

    Wound Healing

    • Begins with inflammation
    • Involves regeneration and repair

    Regeneration

    • Replacement of damaged tissue with native tissue
    • Regenerative capacity varies between tissues:
      • Labile tissues: Stem cells are constantly active, capable of continuous regeneration
        • Examples: Small and large bowel, skin, bone marrow
      • Stable tissues: Cells are quiescent but can re-enter the cell cycle to regenerate when necessary
        • Example: Liver regeneration by compensatory hyperplasia after partial resection
      • Permanent tissues: Lack significant regenerative potential
        • Examples: Myocardium, skeletal muscle, neurons

    Repair

    • Replacement of damaged tissue with fibrous scar
    • Occurs when regenerative stem cells are lost or tissue lacks regenerative capacity
    • Initial phase of repair is granulation tissue formation
      • Consists of fibroblasts, capillaries, and myofibroblasts
    • Eventually leads to scar formation
      • Type III collagen is replaced by type I collagen
        • Type III: Pliable and found in granulation tissue, embryonic tissue, uterus and keloids
        • Type I: Strong and found in skin, bone, tendons, and most organs
        • Collagenase removes type III collagen
        • Collagenase requires zinc as a cofactor

    Mechanisms of Tissue Regeneration and Repair

    • Mediated by paracrine signaling via growth factors (e.g., macrophages secrete growth factors that target fibroblasts)
    • Growth factors interact with receptors triggering gene expression and cellular growth
    • Examples of mediators include:
      • TGF-α: Epithelial and fibroblast growth factor
      • TGF-β: Important fibroblast growth factor; also inhibits inflammation
      • Platelet-derived growth factor: Growth factor for endothelium, smooth muscle, and fibroblasts
      • Fibroblast growth factor: Important for angiogenesis; also mediates skeletal development
      • Vascular endothelial growth factor (VEGF): Important for angiogenesis

    Normal and Aberrant Wound Healing

    • Cutaneous healing occurs via:
      • Primary intention: Wound edges are brought together (e.g., suturing); minimal scar formation
      • Secondary intention: Edges are not approximated; granulation tissue fills the defect
      • Delayed wound healing can happen due to:
        • Infection (most common; S. aureus is the most frequent cause)
        • Vitamin C, copper, or zinc deficiency:
          • Vitamin C: Needed for collagen hydroxylation and cross-linking
          • Copper: Cofactor for lysyl oxidase, which cross-links collagen
          • Zinc: Cofactor for collagenase
        • Other causes: Foreign body, ischemia, diabetes, and malnutrition
    • Dehiscence: Rupture of a wound; most commonly seen after abdominal surgery
    • Hypertrophic scar: Excess scar tissue production localized to the wound
    • Keloid: Excessive scar tissue production out of proportion to the wound:
      • Characterized by excess type III collagen
      • Genetic predisposition (more common in African Americans)
      • Classically affects earlobes, face, and upper extremities

    Scleroderma

    • Scleroderma is an autoimmune disease often caused by inflammation and fibrosis in the skin, and may affect the connective tissues.
    • Different Types of Scleroderma:
      • Limited type: Skin involvement is limited (hands and face) with late visceral involvement. It often presents with CREST syndrome: Calcinosis/anti-Centromere antibodies, Raynaud phenomenon, Esophageal dysmotility, Sclerodactyly, and Telangiectasias of the skin.
      • Diffuse type: Skin involvement is diffuse with early visceral involvement. Any organ can be involved, including vessels (Raynaud phenomenon), GI tract (esophageal dysmotility and reflux), Lungs (interstitial fibrosis and pulmonary hypertension), Kidneys (scleroderma renal crisis). Diffuse type is often highly associated with antibodies to DNA topoisomerase I (anti-Scl-70).

    Mixed Connective Tissue Disease

    • Autoimmune-mediated tissue damage with mixed features of Systemic Lupus Erythematosus (SLE), systemic sclerosis, and polymyositis.
    • Characterized by ANA and serum antibodies to U1 ribonucleoprotein.

    Wound Healing

    • Occurs via a combination of regeneration and repair.
    • Regeneration : Replacement of damaged tissue with native tissue; dependent on the regenerative capacity of the tissue.
      • Labile Tissues: continuously cycle to regenerate the tissue.
        • Small and large bowel (stem cells are in the mucosal crypts)
        • Skin (stem cells are in the basal layer)
        • Bone marrow (hematopoietic stem cells)
      • Stable Tissues: comprised of cells that are quiescent, but can re-enter the cell cycle to regenerate tissue when necessary.
        • Classic example is regeneration of liver by compensatory hyperplasia after partial resection.
      • Permanent Tissues: Lack significant regenerative potential (e.g., myocardium, skeletal muscle, and neurons).

    Repair

    • Replacement of damaged tissue with fibrous scar.
    • Occurs when regenerative stem cells are lost or when a tissue lacks regenerative capacity.
    • Granulation tissue formation: Initial phase of repair.
      • Consists of fibroblasts (deposit type III collagen), capillaries (provide nutrients), and myofibroblasts (contract wound).
    • Scar formation: Eventually type III collagen is replaced with type I collagen.
      • Type III collagen: Pliable and present in granulation tissue, embryonic tissue, uterus, and keloids.
      • Type I collagen: Has high tensile strength and is present in skin, bone, tendons, and most organs.
      • Collagenase: Removes type III collagen and requires zinc as a cofactor.

    Mechanisms of Tissue Regeneration and Repair

    • Mediated by paracrine signaling via growth factors (e.g., macrophages secrete growth factors that target fibroblasts).
    • Interaction of growth factors with receptors results in gene expression and cellular growth.
    • Examples of mediators include:
      • TGF-α: epithelial and fibroblast growth factor
      • TGF-β: important fibroblast growth factor; also inhibits inflammation
      • Platelet-derived growth factor: Growth factor for endothelium, smooth muscle, and fibroblasts
      • Fibroblast growth factor: Important for angiogenesis; also mediates skeletal development
      • Vascular endothelial growth factor (VEGF): Important for angiogenesis

    Normal and Aberrant Wound Healing

    • Cutaneous healing: Occurs via primary or secondary intention.
      • Primary intention: Wound edges are brought together (e.g., suturing of a surgical incision); leads to minimal scar formation.
      • Secondary intention: Edges are not approximated. Granulation tissue fills the defect; myofibroblasts then contract the wound, forming a scar.
    • Delayed wound healing:
      • Infection: Most common cause; Staphylococcus aureus is the most common offender.
      • Vitamin C, copper, or zinc Deficiency:
        • Vitamin C is an important cofactor in the hydroxylation of proline and lysine procollagen residues, which is necessary for eventual collagen cross-linking.
        • Copper is a cofactor for lysyl oxidase, which cross-links lysine and hydroxylysine to form stable collagen.
        • Zinc is a cofactor for collagenase, which replaces the type III collagen of granulation tissue with stronger type I collagen.
      • Other causes include foreign body, ischemia, diabetes, and malnutrition.
    • Dehiscence: Rupture of a wound; most commonly seen after abdominal surgery.
    • Hypertrophic scar: Excess production of scar tissue that is localized to the wound.
    • Keloid: Excess production of scar tissue that is out of proportion to the wound.
      • Characterized by excess type III collagen.
      • Genetic predisposition (more common in African Americans).
      • Classically affects earlobes, face, and upper extremities.

    Systemic Sclerosis (Scleroderma)

    • Autoimmune disease characterized by fibrosis (excessive collagen deposition) in skin and internal organs.
    • Two clinical subtypes: limited and diffuse.
    • Limited type: Skin involvement is limited (hands and face) with late visceral involvement.
      • Prototype is CREST syndrome:
        • Calcinosis (calcium deposits in the skin)
        • Anti-Centromere antibodies
        • Raynaud phenomenon (episodes of vasoconstriction in the fingers and toes)
        • Esophageal dysmotility (difficulty swallowing)
        • Sclerodactyly (thickening and tightening of skin on fingers and toes)
        • Telangiectasias (dilated blood vessels, usually on the face and fingers)
    • Diffuse type: Skin involvement is diffuse with early visceral involvement.
      • Any organ can be involved.
      • Commonly involved organs include:
        • Vessels (Raynaud phenomenon)
        • GI tract (esophageal dysmotility and reflux)
        • Lungs (interstitial fibrosis and pulmonary hypertension)
        • Kidneys (scleroderma renal crisis)
      • Highly associated with antibodies to DNA topoisomerase I (anti-Scl-70).

    Mixed Connective Tissue Disease

    • Autoimmune-mediated tissue damage with mixed features of Systemic Lupus Erythematosus (SLE), Systemic Sclerosis (scleroderma), and Polymyositis (muscle inflammation).
    • Characterized by ANA (antinuclear antibody) along with serum antibodies to U1 ribonucleoprotein.

    Wound Healing

    • Initiated when inflammation begins.
    • Occurs via a combination of regeneration and repair.

    Regeneration

    • Replacement of damaged tissue with native tissue; dependent on the regenerative capacity of tissue.
    • Tissues are divided into three types based on regenerative capacity: labile, stable, and permanent.
    • Labile tissues possess stem cells that continuously cycle to regenerate the tissue.
      • Small and large bowel (stem cells in mucosal crypts)
      • Skin (stem cells in the basal layer)
      • Bone marrow (hematopoietic stem cells)
    • Stable tissues are comprised of cells that are quiescent (G0), but can reenter the cell cycle to regenerate tissue when necessary.
      • Classic example is regeneration of the liver by compensatory hyperplasia after partial resection. Each hepatocyte produces additional cells and then reenters quiescence.
    • Permanent tissues lack significant regenerative potential (e.g., myocardium, skeletal muscle, and neurons).

    Repair

    • Replacement of damaged tissue with fibrous scar.
    • Occurs when regenerative stem cells are lost (e.g., deep skin cut) or when a tissue lacks regenerative capacity (e.g., healing after a myocardial infarction).
    • Granulation tissue formation is the initial phase of repair.
      • Consists of fibroblasts (deposit type III collagen), capillaries (provide nutrients), and myofibroblasts (contract wound).
    • Eventually results in scar formation, in which type III collagen is replaced with type I collagen.
      • Type III collagen is pliable and present in granulation tissue, embryonic tissue, uterus, and keloids.
      • Type I collagen has high tensile strength and is present in skin, bone, tendons, and most organs.
      • Collagenase removes type III collagen and requires zinc as a cofactor.

    Mechanisms of Tissue Regeneration and Repair

    • Mediated by paracrine signaling via growth factors (e.g., macrophages secrete growth factors that target fibroblasts).
    • Interaction of growth factors with receptors (e.g., epidermal growth factor with growth factor receptor) results in gene expression and cellular growth.

    Examples of Mediators:

    • TGF-α: epithelial and fibroblast growth factor.
    • TGF-β: important fibroblast growth factor; also inhibits inflammation.
    • Platelet-derived growth factor: growth factor for endothelium, smooth muscle, and fibroblasts.
    • Fibroblast growth factor: important for angiogenesis; also mediates skeletal development.
    • Vascular endothelial growth factor (VEGF): important for angiogenesis.

    Normal and Aberrant Wound Healing

    • Cutaneous healing occurs via primary or secondary intention.
      • Primary intention: Wound edges are brought together (e.g., suturing of a surgical incision); leads to minimal scar formation.
      • Secondary intention: Edges are not approximated. Granulation tissue fills the defect; myofibroblasts then contract the wound, forming a scar.

    Delayed Wound Healing

    • Most common cause: Infection (S. aureus is the most common offender).
    • Other causes:
      • Vitamin C, copper, or zinc deficiency:
        • Vitamin C is an important cofactor in the hydroxylation of proline and lysine procollagen residues; hydroxylation is necessary for eventual collagen cross-linking.
        • Copper is a cofactor for lysyl oxidase, which cross-links lysine and hydroxylysine to form stable collagen.
        • Zinc is a cofactor for collagenase, which replaces the type III collagen of granulation tissue with stronger type I collagen.
      • Foreign body, ischemia, diabetes, and malnutrition.

    Dehiscence

    • Rupture of a wound; most commonly seen after abdominal surgery.

    Hypertrophic Scar

    • Excess production of scar tissue that is localized to the wound.

    Keloid

    • Excess production of scar tissue that is out of proportion to the wound.
      • Characterized by excess type III collagen.
      • Genetic predisposition (more common in African Americans).
      • Classically affects earlobes, face, and upper extremities.

    Systemic Sclerosis (Scleroderma)

    • Characterized by fibrosis of skin and internal organs
    • Two main types:
      • Limited type: Skin involvement is limited (hands and face) with late visceral involvement.
        • Prototype is CREST syndrome: Calcinosis/anti-Centromere antibodies, Raynaud phenomenon, Esophageal dysmotility, Sclerodactyly, and Telangiectasias of the skin
      • Diffuse type: Skin involvement is diffuse with early visceral involvement
        • Any organ can be involved.
        • Commonly involved organs include vessels, GI tract, lungs, and kidneys
        • Highly associated with antibodies to DNA topoisomerase I (anti-Scl-70).

    Mixed Connective Tissue Disease

    • Autoimmune-mediated tissue damage with mixed features of SLE, systemic sclerosis, and polymyositis
    • Characterized by ANA along with serum antibodies to U1 ribonucleoprotein

    Wound Healing

    • Healing is initiated when inflammation begins.
    • Occurs via a combination of regeneration and repair.

    Regeneration

    • Replacement of damaged tissue with native tissue
    • Dependent on regenerative capacity of tissue
    • Tissues are divided into three types based on regenerative capacity: labile, stable, and permanent.
    • Labile tissues possess stem cells that continuously cycle to regenerate the tissue:
      • Small and large bowel (stem cells in mucosal crypts)
      • Skin (stem cells in basal layer)
      • Bone marrow (hematopoietic stem cells)
    • Stable tissues are comprised of cells that are quiescent (G0), but can reenter the cell cycle to regenerate tissue when necessary:
      • Classic example is regeneration of liver by compensatory hyperplasia after partial resection.
    • Permanent tissues lack significant regenerative potential (e.g., myocardium, skeletal muscle, and neurons)

    Repair

    • Replacement of damaged tissue with fibrous scar
    • Occurs when regenerative stem cells are lost or when a tissue lacks regenerative capacity
    • Granulation tissue formation is the initial phase of repair:
      • Consists of fibroblasts (deposit type III collagen), capillaries (provide nutrients), and myofibroblasts (contract wound)
    • Eventually results in scar formation, in which type III collagen is replaced with type I collagen:
      • Type III collagen is pliable and present in granulation tissue, embryonic tissue, uterus, and keloids.
      • Type I collagen has high tensile strength and is present in skin, bone, tendons, and most organs.
      • Collagenase removes type III collagen and requires zinc as a cofactor.

    Mechanisms of Tissue Regeneration and Repair

    • Mediated by paracrine signaling via growth factors
    • Interaction of growth factors with receptors results in gene expression and cellular growth.
    • Examples of mediators include:
      • TGF-α - epithelial and fibroblast growth factor
      • TGF-β - important fibroblast growth factor; also inhibits inflammation
      • Platelet-derived growth factor - growth factor for endothelium, smooth muscle, and fibroblasts
      • Fibroblast growth factor - important for angiogenesis; also mediates skeletal development
      • Vascular endothelial growth factor (VEGF) - important for angiogenesis

    Normal and Aberrant Wound Healing

    • Cutaneous healing occurs via primary or secondary intention:
      • Primary intention: Wound edges are brought together; leads to minimal scar formation.
      • Secondary intention: Edges are not approximated. Granulation tissue fills the defect; myofibroblasts then contract the wound, forming a scar.
    • Delayed wound healing occurs in:
      • Infection (most common cause; S aureus is the most common offender)
      • Vitamin C, copper, or zinc deficiency:
        • Vitamin C is an important cofactor in the hydroxylation of proline and lysine procollagen residues; hydroxylation is necessary for eventual collagen cross-linking.
        • Copper is a cofactor for lysyl oxidase, which cross-links lysine and hydroxylysine to form stable collagen.
        • Zinc is a cofactor for collagenase, which replaces the type III collagen of granulation tissue with stronger type I collagen.
      • Other causes include foreign body, ischemia, diabetes, and malnutrition.
    • Dehiscence is rupture of a wound; most commonly seen after abdominal surgery.
    • Hypertrophic scar is excess production of scar tissue that is localized to the wound.
    • Keloid is excess production of scar tissue that is out of proportion to the wound:
      • Characterized by excess type III collagen
      • Genetic predisposition (more common in African Americans)
      • Classically affects earlobes, face, and upper extremities.

    Scleroderma

    • Characterised by fibrosis in the skin and internal organs.
    • Can be limited or diffuse.
    • Limited type involves hands and face with later visceral involvement. This type includes CREST syndrome which involves:
      • Calcinosis
      • Anti-Centromere antibodies
      • Raynaud phenomenon
      • Esophageal dysmotility
      • Sclerodactyly
      • Telangiectasias of the skin
    • Diffuse type involves the skin diffusely with early visceral involvement, any organ can be affected.
      • Common visceral involvement include:
        • Vessels (Raynaud phenomenon)
        • GI tract (esophageal dysmotility and reflux)
        • Lungs (interstitial fibrosis and pulmonary hypertension)
        • Kidneys (scleroderma renal crisis)
    • Highly associated with antibodies to DNA topoisomerase I (anti-Scl-70).

    Mixed Connective Tissue Disease

    • Autoimmune-mediated tissue damage with features of systemic lupus erythematosus, systemic sclerosis, and polymyositis.
    • Characterised by Antinuclear Antibodies (ANA) along with serum antibodies to U1 ribonucleoprotein

    Wound Healing

    • Initiated when inflammation begins.
    • Occurs via regeneration and repair.

    Regeneration

    • Replacement of damaged tissue with native tissue.
    • Dependent on regenerative capacity of the tissue.
    • Tissue types are divided into three based on their regenerative capacity: labile, stable, and permanent.
    • Labile tissues possess stem cells that continuously cycle to regenerate the tissue.
      • Examples of labile tissues include:
        • Small and large bowel
        • Skin
        • Bone marrow
    • Stable tissues have cells that are quiescent (G 0) but can re-enter the cell cycle to regenerate tissue when needed.
      • Classic example is the regeneration of the liver by compensatory hyperplasia after partial resection.
    • Permanent tissues lack significant regenerative potential. Examples include:
      • Myocardium
      • Skeletal muscle
      • Neurons

    Repair

    • Replacement of damaged tissue with fibrous scar.
    • Occurs when regenerative stem cells are lost, or when tissue lack regenerative capacity.
    • Granulation tissue formation is the initial phase of repair.
      • Consists of fibroblasts, capillaries, and myofibroblasts.
    • Scar formation occurs when type III collagen is replaced with type I collagen.
      • Type I collagen has high tensile strength and is present in skin, bone, tendons, and most organs.
      • Type III collagen is pliable and present in granulation tissue, embryonic tissue, uterus, and keloids.
      • Collagenase removes type III collagen and requires zinc as a cofactor.

    Mechanisms of Tissue Regeneration and Repair

    • Mediated by paracrine signaling via growth factors.
    • Interaction of growth factors with receptors leads to gene expression and cellular growth.
    • Examples of growth factors include:
      • TGF-α
      • TGF-β
      • Platelet-derived growth factor
      • Fibroblast growth factor
      • Vascular endothelial growth factor (VEGF)

    Normal and Aberrant Wound Healing

    • Cutaneous healing occurs via primary or secondary intention.
      • Primary intention - Wound edges are brought together (e.g., suturing of a surgical incision) and results in minimal scar formation.
      • Secondary intention - Edges are not approximated and granulation tissue fills the defect, myofibroblasts contract the wound forming a scar.
    • Delayed wound healing occurs in:
      • Infection (most common cause - S aureus is the most common offender)
      • Vitamin C, copper, or zinc deficiency
      • Other causes include foreign body, ischemia, diabetes, and malnutrition.
    • Dehiscence - Rupture of a wound, mostly seen after abdominal surgery.
    • Hypertrophic scar - Excess production of scar tissue localised to the wound.
    • Keloid - Excess production of scar tissue that's out of proportion to the wound.
      • Characterised by excess type III collagen.
      • Genetic predisposition (More common in African Americans).
      • Classically affects earlobes, face, and upper extremities.

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    Description

    Explore the mechanisms, types, and characteristics of Systemic Sclerosis, along with Mixed Connective Tissue Disease. This quiz delves into the autoimmune aspects, clinical features, and the processes of wound healing and regeneration. Test your knowledge on these interconnected topics in rheumatology.

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