Immunology: Adaptive Immunity and Neutrophils

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Questions and Answers

What does the speckled pattern in antinuclear antibodies indicate?

Antibodies to chromatin and histones

Presence of uniform or variable-sized speckles (correct)

Antibodies specific to double-stranded DNA

Antibodies to RNA

What is the nucleolar pattern in antinuclear antibodies associated with?

High levels of double-stranded DNA antibodies

Presence of homogeneous nuclear staining

Presence of peripheral staining patterns

Presence of discrete spots of fluorescence within the nucleus (correct)

Which of the following is the least specific pattern of fluorescence in antinuclear antibodies?

Centromeric pattern

Homogeneous pattern

Nucleolar pattern

Speckled pattern (correct)

What type of staining pattern usually reflects antibodies to double-stranded DNA?

Rim or peripheral staining patterns Signup and view all the answers

Which autoantibody pattern generally reflects antibodies to nuclear envelope proteins?

Rim or peripheral staining patterns Signup and view all the answers

What is the primary function of mannose receptors in the immune system?

To recognize microbial substances and induce phagocytosis Signup and view all the answers

Which type of immunity is primarily responsible for defense against intracellular microbes?

Cell-mediated immunity, mediated by T lymphocytes Signup and view all the answers

What are the products of B lymphocytes in the adaptive immune response?

Immunoglobulins also known as antibodies Signup and view all the answers

What characterizes the lymphocytes involved in adaptive immunity?

They express highly specific receptors for a variety of antigens Signup and view all the answers

Which statement about the immune system is true regarding T cells?

They play a crucial role in cell-mediated immunity Signup and view all the answers

Which of the following is a hallmark of chronic rejection in kidneys?

Interstitial mononuclear cell infiltrates Signup and view all the answers

What type of immunodeficiency is genetically determined and typically detected in early childhood?

Primary (or congenital) immunodeficiency Signup and view all the answers

What characterizes leukocyte adhesion deficiency type I?

Defective synthesis of the B2 chain Signup and view all the answers

What is a common feature of chronic renal failure due to vascular changes?

Intimal thickening with inflammation Signup and view all the answers

Which of the following is NOT a cause of secondary immunodeficiencies?

Genetic abnormalities Signup and view all the answers

What condition is characterized by defective fusion of phagosomes and lysosomes?

Chédiak-Higashi syndrome Signup and view all the answers

What effect do vascular lesions have on renal tissue?

Interstitial fibrosis and tubular atrophy Signup and view all the answers

What is a consequence of inherited defects in leukocyte function?

Recurrent bacterial infections Signup and view all the answers

What histological changes are characteristic of systemic sclerosis in the skin?

Edema and perivascular infiltrates with CD4+ t cells Signup and view all the answers

What structural changes occur in the lower two thirds of the esophagus due to systemic sclerosis?

Rubber-hose-like inflexibility Signup and view all the answers

What are the musculoskeletal system changes associated with the early stages of systemic sclerosis?

Hypertrophy and hyperplasia of synovial soft tissues Signup and view all the answers

Which feature is not commonly seen in the skin of patients with advanced systemic sclerosis?

Excessive vascularization Signup and view all the answers

What type of hypertension is observed in a significant percentage of systemic sclerosis patients?

Ominously rapid malignant hypertension Signup and view all the answers

Which of the following is a prominent vascular change seen in the kidneys of patients with systemic sclerosis?

Intimal thickening due to mucinous material Signup and view all the answers

Systemic sclerosis is associated with which significant digestive tract change?

Progressive atrophy and collagenous fibrous replacement Signup and view all the answers

What is the characteristic histological appearance of collagen fibers in the skin of patients with systemic sclerosis?

Eosinophilic degeneration of collagen fibers Signup and view all the answers

What is a common pulmonary complication associated with systemic sclerosis?

Pulmonary hypertension Signup and view all the answers

What age group has the peak incidence of systemic sclerosis?

50 to 60 years Signup and view all the answers

Which skin manifestation is primarily associated with systemic sclerosis?

Skin thickening Signup and view all the answers

Which antibody is highly specific for diffuse systemic sclerosis?

Anti-Scl 70 Signup and view all the answers

What is a characteristic feature of mixed connective tissue disease?

High titers of antibodies to U1 ribonucleoprotein Signup and view all the answers

What percentage of systemic sclerosis patients typically present with dysphagia?

More than 50% Signup and view all the answers

What serious manifestation is associated with systemic sclerosis?

Malignant hypertension Signup and view all the answers

What is the typical gender ratio for systemic sclerosis cases?

3:1 Signup and view all the answers

Study Notes

Immune System Overview

Neutrophils detect bacterial proteins, stimulating chemotactic responses.
Mannose receptors recognize microbial substances, inducing phagocytosis.

Adaptive Immunity

Comprised of lymphocytes and their products, including antibodies.
Two main types:
- Humoral Immunity: Protects against extracellular microbes and toxins; mediated by B lymphocytes and antibodies (immunoglobulins).
- Cell-Mediated Immunity: Defends against intracellular microbes; mediated by T lymphocytes.
Both B and T lymphocytes express specific receptors for various substances known as antigens.

Cells of the Immune System

T and B lymphocytes are diverse, specialized, and circulate continuously in blood and lymphatic systems.

Autoimmune Diseases

Systemic Lupus Erythematosus (SLE):
- Characterized by a spectrum of autoantibodies, primarily antinuclear antibodies (ANAs).
- Recognized patterns in indirect immunofluorescence:
  - Homogeneous: Reflects antibodies to chromatin and histones.
  - Rim Staining: Indicates antibodies to double-stranded DNA.
  - Speckled Pattern: Often presents with antibodies to non-DNA nuclear constituents.
  - Nucleolar Pattern: Associated with antibodies to RNA.
Histological features include edema, perivascular infiltrates, collagen degeneration, and potential fibrosis.

Systemic Sclerosis (Scleroderma)

Morphological changes include:
- Skin: Increased collagen in the dermis, subcutaneous calcifications; claw-like finger appearance and facial tightness in advanced stages.
- Alimentary Tract: Affects ~90% of patients, causing atrophy and fibrosis, especially in the esophagus, leading to hypomotility.
- Musculoskeletal System: Early inflammation of synovium, leading to fibrosis.
- Kidneys: Vascular lesions, potential for hypertension in 30% of patients.
- Lungs: Involvement in >50% of patients; may include pulmonary hypertension and interstitial fibrosis.

Clinical Features of Systemic Sclerosis

Higher incidence in females (3:1 ratio) around 50-60 years of age.
Notable symptoms include cutaneous changes, Raynaud phenomenon, dysphagia, and risk of malignant hypertension.
Autoantibodies:
- Anti-Scl 70 (DNA topoisomerase I) correlates with pulmonary fibrosis.
- Anticentromere antibody linked to CREST syndrome.

Mixed Connective Tissue Disease

Exhibits features from SLE, systemic sclerosis, and polymyositis.
Characterized by high levels of ribonucleoprotein particle antibodies.
Often manifests as finger synovitis, Raynaud phenomenon, and mild myositis; renal involvement is typically modest.

Immunodeficiency Syndromes

Classified into:
- Primary (Congenital): Genetically determined, often detected in early childhood.
- Secondary (Acquired): Result from factors like cancers, infections, malnutrition, or immune suppression therapies.

Primary Immunodeficiencies - Defects in Innate Immunity

Defects in Leukocyte Function:
- Genetic defects leading to poor leukocyte recruitment.
  - Type I: Defective B2 chain in integrins.
  - Type II: Defective ligand for selectins.
Inherited Phagolysosome Function Defects:
- Increased susceptibility to infections due to neutropenia and defective phagocytic function.
- Chédiak-Higashi Syndrome: Autosomal recessive condition resulting in ineffective phagocyte function, characterized by neutropenia and delayed microbial killing.

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Description

Test your knowledge on the role of neutrophils in detecting bacterial proteins and stimulating immune responses. This quiz delves into the components of adaptive immunity, including lymphocytes and humoral immunity, and their function in the immune system. Understand how these cells work together to protect against pathogens.