Type III hypersensitivity (mechanism of disease) with examples скачать в хорошем качестве

Type III hypersensitivity (mechanism of disease) with examples

This is a flowchart for Type III hypersensitivity, covering the etiology, pathophysiology, and manifestations with examples. ADDITIONAL TAGS: Tetanus or diphtheria vaccine are the Ag → Arthus reaction Genetics → farmers → bird droppings, spores (from HVAC, moldy hay, sugar cane cheese casings, paints, compost), sawdust microbes, chemicals (isocyanates) form Ag → Hypersensitivity pneumonitis Remission and relapse affecting any organ, most commonly arthritis, malar rash, Raynaud phenomenon, fever, fatigue, pleuritis / pericarditis → pleuritic sharp chest pain, friction rub, seizures, psychosis Risk factors / SDOH Cell / tissue damage Vascular / flow physiology Type III hypersensitivity Medicine / iatrogenic Infectious / microbial Environment / toxins Immunology / inflammation Signs / symptoms Disease / condition / results Diet / nutrition Genetics / hereditary Neoplasm / cancer Pathophysiology Etiology Manifestations Inflammation Complexes deposited in tissues (blood vessels, joints, glomerular basement membranes, etc) Formation of immune complex (Ag-Ab complex) IgG in circulation Soluble antigen in circulation Initiates complement cascade Chemotaxis of neutrophils IgG binds to Fc receptor on neutrophils, releasing lysosomal enzymes Damages local tissue Cell death Systemic lupus erythematosus +/- lupus nephritis +/- thrombosis Joint pain, swelling, synovial destruction, deformities, morning stiffness (MCP and PIP joints); rheumatoid nodules pulmonary fibrosis=dyspnea, dry cough, fatigue, inspiratory crackles; AAS= neck pain, cervical radiculopathy, spinal cord compression; Felty = arthritis, splenomegaly, and neutropenia Rheumatoid arthritis +/- pulmonary fibrosis +/- atlantoaxial subluxation +/- Felty syndrome Nephritic syndrome: hematuria (tea- or cola-colored urine), mild proteinuria, edema, hypertension Group A strep tonsillopharyngitis or skin infections → Poststreptococcal glomerulonephritis Asymptomatic OR Recurring episodes of gross hematuria, flank pain, low fever; +/- nephritic syndrome Mucosal (respiratory or GI) infections → IgA immune complexes deposit in kidney → IgA nephropathy Polyarteritis nodosa Systemic vasculitis of medium-sized vessels Fever, weight loss, muscle / joint pain; AKI → hypertension, MI → chest pain, sweating, skin → rash, ulcers, nodules, neuro → stroke, polyneuropathy, GI → abd pain, melena, nausea, vomiting. Spares the lung (vs other vasculitides) Tender, symmetrical palpable purpura on the lower limbs; +/- subcutaneous nodules, urticaria, ulcers, vesicles; +/- arthralgias Viral (HIV, HCV), drugs (propylthiouracil, hydralazine, allopurinol) form Ag → Cutaneous small-vessel vasculitis, aka drug-induced or hypersensitivity vasculitis Acute: fever, flu-like headache, bodyache, malaise, fine crackles Subacute: insidious cough, dyspnea, fatigue over weeks to months Chronic: progressive dyspnea, weight loss, cough, fatigue, cyanosis, rales Antitoxin, antivenom, allopurinol, antibiotics, or Hep B, rabies are the Ag → Serum sickness and SS-like reaction Fever, rash, arthralgias occuring 1-3 weeks after exposure; +/- lymphadenopathy, +/- headache, +/- blurred vision, +/- abdominal pain/nausea/vomiting/diarrhea, +/- edema Similar to cutaneous small-vessel vasculitis; : swelling, erythema, hemorrhage; +/- superficial skin necrosis after booster vaccination