Blood Transfusion Reactions & Nonneoplastic disorders.pdf

(1) Blood Transfusion Reactions (2) Nonneoplastic disorders of white cells Pathophysiology I Final exam: Monday April 15th at 9 am 100 questions at 75 sec per question => 125 min (+5 min) => 2 hours 10 min PASG 61310 Pathophysiology I L28 April 9th, Spring 2024 Ithaca College, Physician Assistant Pr...

(1) Blood Transfusion Reactions (2) Nonneoplastic disorders of white cells Pathophysiology I Final exam: Monday April 15th at 9 am 100 questions at 75 sec per question => 125 min (+5 min) => 2 hours 10 min PASG 61310 Pathophysiology I L28 April 9th, Spring 2024 Ithaca College, Physician Assistant Program 50 questions from the first half (before midterm) 50 questions from the second half (after midterm) Elena Mueller, PhD Blood transfusion Final self-reflection homework (5% of grade on the syllabus) Topic: ‘The importance of self-assessment in PA education’ Complete the practice quiz (or any other self-assessment source (Osmosis ‘quiz all’, Access Medicine, other resources)). https://new-acc-space-11787.ispring.com/app/preview/9e153812-f69d-11ee-a084-721907282f7d Write a paragraph reflecting on your habits for self-assessment § Which resource do you use? § How many questions per study session? § How often? § Is it daily? § Your plan for continuing self-assessment (for example, 10 questions a day at 7:30 am) § May include result from the quiz above § Submit on eMedley under ‘Final Self-reflection Homework” § Due date: Monday April 15th before 9 am. Transfer of blood products ABO Ags expressed on all cells Carbohydrate molecules linked to cell surface proteins A fucosyltransferase that almost all individuals have generates a core glycan (H Ag) A single glycosyltransferase further modifies the H Ag, with 3 alleles (A, B, O) Individuals lacking A or B make Abs against that group (thought to be due to similarities between the AB Ags and carbohydrate Ags on commensal bacteria) Mismatch results in complement activation, hemolysis, disseminated intravascular coagulation that eats up clotting factors, contributing to hemorrhage, cytokine storm Other Ags (Lewis and Rh exist) Ø There are over 100 different red cell surface membrane proteins. Ø Many of these are polymorphic and have come to attention because they induce clinically significant immune responses when transfused into mismatched recipients ABO Blood Groups H antigen: R-acetylglucosamine-galactose-fucose A antigen: Glycosyltransferase adds Nacetylgalactosamine to the subterminal galactose B antigen: Glycosyltransferase adds galactose to the subterminal galactose The terminal polysaccharide structures of H substance and A and B antigens. Fuc, fucose Gal, galactose GalNAc, N-acetyl galactosamine GlcNAc, N-acetyl glucosamine R, core carbohydrate moiety q The A and B antigens are defined by the terminal sugar that is attached to glycoproteins and glycosphingolipids by specific transferases q The precursor for these terminal sugars is the H antigen, which has the sequence R-acetylglucosamine-galactose-fucose q The A and B antigens are defined by the terminal sugar that is attached to glycoproteins and glycosphingolipids by specific transferases q The precursor for these terminal sugars is the H antigen, which has the sequence R-acetylglucosamine-galactosefucose q The A antigen is formed by a glycosyltransferase that catalyzes the addition of N-acetylgalactosamine to the subterminal galactose q The B antigen is formed by an allelic variant that catalyzes the addition of galactose to the subterminal galactose q The A antigen is formed by a glycosyltransferase that catalyzes the addition of N-acetylgalactosamine to the subterminal galactose q OO homozygotes lack A and B terminal transferases, they express only the unmodified H antigen on their red cell surfaces. These individuals have the O blood type q The B antigen is formed by an allelic variant that catalyzes the addition of galactose to the subterminal galactose q Those who have type A or type B red cells are either homozygotes (AA or BB) or heterozygotes (AO or BO) q OO homozygotes lack A and B terminal transferases, they express only the unmodified H antigen on their red cell surfaces q Those with type AB red cells inherit one A allele and one B allele from their two parents. ABO blood group biology Blood transfusion Transfer of blood products ABO Ags expressed on all cells The ABO system was discovered by Landsteiner in 1900 while investigating the basis of compatible and incompatible transfusions in humans Carbohydrate molecules linked to cell surface proteins A fucosyltransferase that almost all individuals have generates a core glycan (H Ag) A single glycosyltransferase further modifies the H Ag, with 3 alleles (A, B, O) Ø Individuals lacking A or B make Abs against that group (thought to be due to similarities between the AB Ags and carbohydrate Ags on commensal bacteria) Ø Mismatch results in complement activation, hemolysis, disseminated intravascular coagulation that eats up clotting factors, contributing to hemorrhage, cytokine storm Ø Other Ags (Lewis and Rh) exist Blood transfusion § From fetal development throughout life, individuals are exposed to A-like and B-like carbohydrate antigens from a variety of sources and, as a result, develop antigen-specific “natural” IgG and IgM immunoglobulins even in the absence of blood transfusion § ABO antibodies fix complement and cause intravascular hemolysis § Individuals with type A red cells have anti-B antibodies in their plasma § whereas those with type B red cells have anti-A antibodies. § Individuals with type O red cells have both anti-A and anti-B antibodies in their plasma. They are sometimes called universal donors § group AB individuals lack both anti-A and anti-B antibodies in their plasma and are sometimes called universal recipients recipient Abs in the blood of recipient ABO Incompatible Blood Transfusion Reactions Antibody type: IgM Area of hemolysis: Intravascular Results: Hemoglobinemia leading to acute renal failure; high mortality rate. Important points: Anti-A and anti-B IgM are naturally occurring antibodies; therefore, an ABO incompatible red cell transfusion does not require a previous exposure to an incompatible ABO blood type. ABO Incompatible Blood Transfusion Reactions o Immune-mediated acute hemolysis occurs when the recipient preformed Abs lyse transfused donor RBCs and may occur during or 24 h after transfusion. o The anti-A or anti-B Abs are responsible for the majority of the most severe reactions, which can be fatal. o However, alloAbs directed against other RBC Ags (i.e., Rh, Kell, and Duffy) are also responsible for severe hemolytic reactions. o Such dramatic reactions are usually caused by a failure in product or patient identification, erroneous blood grouping, or unidentified anti-RBC alloimmunization in the recipient. o Hemolysis, most often of lesser severity, may also occur upon tranfusion of BCs containing incompatible plasma with a large amount of alloAbs directed against the recipient’s RBCs. o This may typically occur after transfusion of a PC containing ABO-incompatible plasma. Estimated frequencies of acute and chronic hemolytic adverse reactions are 1–10 and 5–40 per 105 transfused BCs, respectively. Mechanisms of transfusion hemolytic reactions Complement membrane-attack complex The membrane-attack complex (MAC) is a tubular structure that forms a transmembrane pore in the target cell’s plasma membrane C5b-9 C5b C6 C7 C8 C9 § § § Acute responses will involve preexisting antibodies (Abs), naturally occurring anti-A/anti-B IgM or IgG directed against other RBC Ab and resulting from prior sensitization. Upon interaction with cognate antigen (Ag) on transfused red blood cells (RBCs), recipient allogeneic Ab (alloAb), mostly natural anti-A/anti-B IgM, may fix and activate complement up to C5/C9. Formation of membrane attack complex (MAC) will create pores in transfused RBCs with resulting intravascular hemolysis, release of toxic moieties including free hemoglobin responsible for end-organ damage including renal failure, and tissue factors contributing to occurrence of disseminated intravascular coagulation (DIC). Mechanisms of transfusion hemolytic reactions B. Complement activation may be incomplete, as typically observed in a delayed hemolytic transfusion reaction involving neoformed allogeneic IgG. In such cases, complement activation up to C3 results in C3b-mediated opsonization of RBCs, extravascular hemolysis, and clearance through immunophagocytosis. Anemia and jaundice will be the primary clinical manifestations. Granulocytes: Neutrophils, Eosinophils, and Basophils o The granulocytes are the most common white blood cells o of these, neutrophils are most abundant, followed by eosinophils and basophils o Developmentally, all three types are similar: o As they mature, their nuclei become more convoluted and multilobed, and each develops a cytoplasm filled with granules. o These granules contain a variety of enzymes, prostaglandins, and mediators of inflammation, with specific factors dependent on the cell type. o Early progenitor cells for each type of granulocyte (“blasts”) are indistinguishable on microscopic examination of the bone marrow, but under the influence of different cytokines, they become morphologically distinct cell types. Mechanisms of transfusion hemolytic reactions C. Lastly, alloAb may not fix complement while ensuring antibody-dependent cellular cytotoxicity (ADCC)–mediated phagocytosis of targeted RBC. Granulocytes: Neutrophils, Eosinophils, and Basophils o Basophils contain very dark blue or purple granules when stained with either Giemsa or Wright stain. o Basophil granules are large and usually obscure the nucleus because of their density. o Normally, basophils function in hypersensitivity reactions. o However, their numbers can be increased in diseases not associated with hypersensitivity, such as chronic myelogenous leukemia. Granulocytes: Neutrophils, Eosinophils, and Basophils Granulocytes: Neutrophils, Eosinophils, and Basophils o o Eosinophils contain large, strikingly “eosinophilic” granules (staining red with Wright or Giemsa stain). o Eosinophil nuclei are usually bilobed. o Normally, eosinophils function as part of the inflammatory response to parasites too large to be engulfed by individual immune cells. o They are also involved in some allergic reactions. Neutrophils contain granules that are “neutrophilic” (ie, neither eosinophilic nor basophilic). o They predominate in the blood, their major function is actually in the tissues; o they must leave the blood by inserting themselves between the endothelial cells of the vasculature to reach sites of injury or infection. o Their granules contain highly active enzymes such as myeloperoxidase, which, along with the free radical oxygen ions produced by membrane enzymes such as nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, kill bacteria that neutrophils ingest via endocytosis or phagocytosis. o They are the “first line of defense” against bacterial pathogens, and low numbers of them (leukopenia) lead directly to a high incidence of significant bacterial infections. o Of all the cells produced by the bone marrow, the neutrophils comprise the greatest fraction. Granulocytes: Neutrophils, Eosinophils, and Basophils o Neutrophils contain granules that are “neutrophilic” o Their life span in blood, only 8 hours, is much shorter than that of any other cell type. o Evidence of their importance and their short survival is commonly manifested, because microscopic examination of a blood smear from a patient with an active infection may show not only increased numbers of mature, multilobed neutrophils (neutrophilia), but also increased numbers of less mature cells. o These less mature cells, released from a large storage pool in the bone marrow, are called bands and have a characteristic horseshoe-shaped nucleus that is not yet fully lobulated. o The phenomenon of finding these cells in the peripheral blood is called a left shift of the granulocyte lineage. Monocytes o Both monocytes and lymphocytes arise from the common stem cell. o The presence of stem cells makes bone marrow transplantation a therapeutic option for immune system disorders and malignancies. o Monocytes have a very long life span, probably several months, but spend only about 3 days in the circulation. o They mostly reside in tissues and act there as immune cells that engulf (phagocytose) bacteria and subsequently can “present” components of these bacteria to lymphocytes in a way that further amplifies and refines the immune response o On blood smear evaluation, monocytes are the largest cells seen, with irregular but not multilobed nuclei and pale blue cytoplasm, often with prominent vacuoles. Lymphocytes Lymphocytes o Lymphocyte precursors leave the marrow early and require extramedullary (outside of the marrow) maturation to become normally functioning immune cells in either the blood or the lymphatic system o Their crucial roles in recognizing “self” versus “nonself” and in modulating virtually all aspects of the immune response. o On microscopic examination of the blood smear, lymphocytes are small cells, slightly larger than an erythrocyte, with dark nuclei essentially filling the entire cell; only a thin rim of light blue cytoplasm is normally seen. o Granules are sparse or absent. Regulation of Distinct Modules of the Immune Response https://pubmed.ncbi.nlm.nih.gov/29677509/ In the classically held view of the immune system, different types of pathogens can shift the equilibrium of the immune response for sufficient eradication of specific pathogens. For example, helminth infection promotes type 2 inflammation, whereas intracellular viral infection results in type 1 inflammation. However, other physiological stimuli can also skew the immune response toward type 1, type 2, or type 3 immunity. Cold exposure results in type 2 inflammation, whereas a diet rich in tryptophan results in production of AHR ligands and promotion of type 3 immunity. These changes in the immune response can then feed back to other non-immune tissues to regulate homeostasis and promote pathologies. Areg, amphregulin; AHR, aryl hydrocarbon receptor; cGRP, calcitonin gene-related peptide; EC, epithelial cells; FAP, fibroadipogenic precursor; NE, norepinephrine; NMU, neuromedin U; VIP, vasoactive intestinal peptide. Hematology Normal cells in peripheral blood. A, Erythrocyte (red blood cell); B, neutrophil (segmented); C, neutrophil (banded); D, eosinophil; E, basophil; F, lymphocyte; G, monocyte; H, platelet. Leukocytosis Leukocytosis q Eosinophilia Ø Leukocytosis is an age-appropriate increase in the white blood cell (WBC) count Ø Elevation of white cell count above 11 x 109 cells/L is usually considered leukocytosis in an adult. Ø The exact value of leukocytosis varies with age Ø Automated hematology analyzers can quickly process whole blood samples for complete blood count and differentials, including RBC count, WBC count, platelet count, hemoglobin and RBC indices, and WBC differentials. Ø WBC comprises neutrophils, lymphocytes, monocytes, basophils, and eosinophils. Ø Hematology analyzers use cytochemistry and fluorescence techniques to differentiate various types of WBCs and flag them as low or high based on appropriate algorithms provided to the machine Leukocytosis q Eosinophilia v Causes Ø Ø Medications § NSAIDs and § common antibiotics (eg, nitrofurantoin, quinolones, cephalosporins, penicillins, sulfa-containing drugs) Allergic conditions § Ø Eosinophils are most commonly elevated in allergic conditions, such as seasonal and environmental allergies. Parasitic infections § The parasitic and infectious etiologies evaluation should be completed, especially if the patient has an exposure history or other risk factors Ø Eosinophils are approximately 1% to 4% of a person's total leukocyte count. Ø Elevations greater than 0.5 x 109 cells/L, which previously correlated with mild eosinophilia, are the generally accepted cut-off for eosinophilia. Ø However, significant elevations over 1.5 x 109 cells/L are the usual cut-off for further evaluation and consideration, especially in multiple CBCs separated in time. Ø Eosinophilia can occur in neoplastic, inflammatory, infectious, parasitic, autoimmune, and allergic conditions. Ø A careful review of prior CBC lab analyses, looking for persistent eosinophilia, which is defined as 2 abnormal CBCs collected with a minimum time interval between the 2 lab draws of 4 weeks, should be completed by the primary care provider to evaluate for the less-benign causes of this phenomenon. Types of immune response Type 2 inflammation is associated with infection with parasitic helminths o Type 1 IR is elicited by viruses, intracellular bacteria, parasites. The actors here are group 1 innate lymphoid cells (ILC1), NK cells, Th1 cells, macrophages, opsonizing IgG isotypes. q Nearly half of the world’s population harbors helminth infections or suffers from allergic disorders. q A common feature of this population is the so-called “type 2 immune response,” which confers protection against helminths, but also promotes pathologic responses associated with allergic inflammation. o Type 2 IR is caused by toxins and multicellular parasites. ILC2, epithelial cells, Th2 lymphocytes, eosinophils, basophils, mast cells, IgE are key players here. o Type 3 IR targets extracellular bacteria and fungi by recruiting ILC3, Th17, neutrophils, opsonizing q the mechanisms that initiate and control type 2 responses remain enigmatic. IgG isotypes. Additional types of IR can be observed in noninfectious pathologies. q Recent advances have revealed a role for the innate immune system in orchestrating type 2 responses against a bewildering array of stimuli, from nanometer-sized allergens to 20-meterlong helminth parasites. All types of IR have the following parts: sensor (ILCs, NK cells) adaptive (T and B cells) effector (neutrophils, eosinophils, basophils, mast cells) https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4078898/ Current Research Topics in Immunology Dysregulation in human disease Type 2 inflammation has been implicated in several chronic diseases: Asthma Atopic dermatitis Chronic sinusitis with nasal polyps Eosinophilic esophagitis Persons with one type 2 inflammatory disease are more likely to have other type 2 inflammatory diseases https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6547860/ In vivo treatments and ex vivo tissue preparation T. muris eggs were generated in-house and tested for infectivity by infecting Rag−/− mice with 200 T. muris eggs. Briefly, worms collected from the cecum of Rag−/− mice at 6 wk p.i. were cultured overnight at 37°C and 5% CO2. Eggs were collected and stored in ultrapure water at room temperature for 7 wk to allow for embryonation. Experimental mice were infected with 200 T. muris eggs by oral gavage and sacrificed on days 7, 14, or 19 p.i. for analysis. At various time points p.i., ceca were harvested, and the number of adult worms in each cecum was ascertained microscopically. Webb LM, Oyesola OO, Früh SP, Kamynina E, Still KM, Patel RK, Peng SA, Cubitt RL, Grimson A, Grenier JK, Harris TH, Danko CG, Tait Wojno ED. The Notch signaling pathway promotes basophil responses during helminth-induced type 2 inflammation. J Exp Med. 2019 Jun 3;216(6):1268-1279. doi: 10.1084/jem.20180131. Graphical Abstract § Type 2 inflammation drives the clearance of gastrointestinal helminth parasites, which infect over two billion people worldwide. § Basophils are innate immune cells that support host-protective type 2 inflammation during murine infection with the helminth Trichuris muris. § However, the mechanisms required for basophil function and gene expression regulation in this context remain unclear. § We show that during T. muris infection, basophils localized to the intestine and up-regulated Notch receptor expression, rendering them sensitive to Notch signals that rapidly regulate gene expression programs. § In vitro, Notch inhibition limited basophil cytokine production in response to cytokine stimulation. § Basophil-intrinsic Notch signaling was required for T. muris–elicited changes in genome-wide basophil transcriptional programs. § Mice lacking basophil-intrinsic functional Notch signaling had impaired worm clearance, decreased intestinal type 2 inflammation, altered basophil localization in the intestine, and decreased CD4+ T helper 2 cell responses following infection. § These findings demonstrate that Notch is required for basophil gene expression and effector function associated with helminth expulsion during type 2 inflammation. Webb LM, Oyesola OO, Früh SP, Kamynina E, Still KM, Patel RK, Peng SA, Cubitt RL, Grimson A, Grenier JK, Harris TH, Danko CG, Tait Wojno ED. The Notch signaling pathway promotes basophil responses during helminth-induced type 2 inflammation. J Exp Med. 2019 Jun 3;216(6):1268-1279. doi: 10.1084/jem.20180131. Abstract Trichuris muris is a natural pathogen of mice and is biologically and antigenically similar to species of Trichuris that infect humans and livestock1. Infective eggs are given by oral gavage, hatch in the distal small intestine, invade the intestinal epithelial cells (IECs) that line the crypts of the cecum and proximal colon and upon maturation the worms release eggs into the environment1. This model is a powerful tool to examine factors that control CD4+ T helper (Th) cell activation as well as changes in the intestinal epithelium. The immune response that occurs in resistant inbred strains, such as C57BL/6 and BALB/c, is characterized by Th2 polarized cytokines (IL-4, IL-5 and IL-13) and expulsion of worms while Th1-associated cytokines (IL-12, IL-18, IFN-γ) promote chronic infections in genetically susceptible AKR/J mice2-6. Th2 cytokines promote physiological changes in the intestinal microenvironment including rapid turnover of IECs, goblet cell differentiation, recruitment and changes in epithelial permeability and smooth muscle contraction, all of which have been implicated in worm expulsion7-15. Here we detail a protocol for propagating Trichuris muris eggs which can be used in subsequent experiments. We also provide a sample experimental harvest with suggestions for post-infection analysis. Overall, this protocol will provide researchers with the basic tools to perform a Trichuris muris mouse infection model which can be used to address questions pertaining to Th proclivity in the gastrointestinal tract as well as immune effector functions of IECs https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3415709/ DISORDERS OF WHITE CELLS DISORDERS OF WHITE CELLS Ø Leukopenia o Neutropenia, o Agranulocytosis Ø Reactive Proliferations of White Cells and Lymph Nodes o Leukocytosis o Lymphadenitis Acute Nonspecific Lymphadenitis Chronic Nonspecific Lymphadenitis Ø Proliferations of white cells can be reactive or neoplastic. Ø Reactive proliferations in the setting of infections or inflammatory processes, when large numbers of leukocytes are needed for an effective host response, are fairly common. Ø Neoplastic disorders, though less frequent, are much more important clinically Ø Hemophagocytic Lymphohistiocytosis q Lymphoid Neoplasms Ø Ø B- and T-Cell Neoplasms o Acute Lymphoblastic Leukemia/Lymphoma Peripheral B-Cell Neoplasms o Chronic Lymphocytic Leukemia/Small Lymphocytic Lymphoma o Follicular Lymphoma o Diffuse Large B-Cell Lymphoma o Burkitt Lymphoma o Mantle Cell Lymphoma o Marginal Zone Lymphomas o Hairy Cell Leukemia Ø Peripheral T- and NK-Cell Neoplasms o Peripheral T-Cell Lymphoma, Unspecified o Anaplastic Large-Cell Lymphoma (ALK Positive) o Adult T-Cell Leukemia/Lymphoma o Mycosis Fungoides/Sézary Syndrome o Large Granular Lymphocytic Leukemia o Extranodal NK/T-Cell Lymphoma Ø Plasma Cell Neoplasms and Related Disorders o Multiple Myeloma o Smoldering Myeloma o Solitary Osseous Plasmacytoma o Lymphoplasmacytic Lymphoma Ø Hodgkin Lymphoma q Myeloid Neoplasms Ø Ø Ø Acute Myeloid Leukemia Myelodysplastic Syndrome Myeloproliferative Neoplasms o Chronic Myeloid Leukemia o Polycythemia Vera o Essential Thrombocytosis o Primary Myelofibrosis Ø Langerhans Cell Histiocytosis Leukocytosis and Neutropenia Changes in neutrophil count are the most common white cell abnormality detected on the automated blood count. Ø Leukocytosis § Increased numbers of neutrophils (leukocytosis) suggest acute or chronic infection or inflammation but can be a sign of many conditions. These include stress, because adrenal corticosteroids cause demargination of neutrophils from blood vessel walls. Ø Neutropenia § Decreased numbers of neutrophils (neutropenia) can be seen in overwhelming infection and benign diseases such as cyclic neutropenia but can also be seen when the bone marrow is infiltrated with tumor or involved by the myelodysplastic syndromes. § Many drugs can also directly suppress marrow production, and because neutrophils have the shortest half-life in the blood of any cell produced by the marrow, their numbers may fall quickly. Cyclic neutropenia Cyclic neutropenia o is rare o provides insight into normal neutrophil production and function o characterized by a lifetime history of neutrophil counts that decrease to zero or near zero for 3–5 days at a time every 3 weeks and then rebound o the peripheral blood neutrophil counts and monocyte counts oscillate in opposite phases on this 3week cycle o Classic, childhood-onset cyclic neutropenia results from heterozygous germline mutations in the gene ELANE (ELAstase, neutrophil expressed), formerly known as ELA2, which encodes for a single enzyme, neutrophil elastase (NE) o NE is found in the primary azurophilic granules of neutrophils and monocytes. o There are approximately 100 cases of childhood cyclic neutropenia in the literature, most of which are consistent with an autosomal dominant inheritance Cyclic neutropenia o The neutrophil count in blood is stable in normal individuals o The marrow reserve exceeds the circulating pool of neutrophils by 5- to 10fold. o This large pool is necessary because it takes nearly 2 weeks for the full development of a neutrophil from an early stem cell within the bone marrow, yet the average life span of a mature neutrophil in blood is less than 12 hours. o In cyclic neutropenia, the storage pool is not adequate o Neutrophil elastase (NE) is postulated to inhibit further differentiation by a myeloblast. Cyclic neutropenia qRegular cyclic variation of monocytes, reticulocytes, and neutrophils in a patient with cyclic neutropenia. qNote that monocytes and reticulocytes tend to rise when neutrophils fall. o Gray sine wave denotes neutrophil count oscillations. In this model, NE is produced by the terminally differentiating cohort of neutrophils and ultimately feeds back to inhibit further production of neutrophils, which results in loss of the inhibitory cycle—at least for a while, until production of the neutrophils resumes, followed again by the inhibitory action of NE in a cyclic manner. Causes of abnormal lymphocyte counts