Biology Past Paper: Hypersensitivities & Autoimmune Diseases

**Topic 26: Hypersensitivities** ================================ **Objectives** -------------- At the completion of the modules and the assigned reading, the student should be able to: **Parham, The Immune System, 5^th^ Ed Topic 27: Autoimmunity basis** ==========================================...

**Topic 26: Hypersensitivities** ================================ **Objectives** -------------- At the completion of the modules and the assigned reading, the student should be able to: **Parham, The Immune System, 5^th^ Ed Topic 27: Autoimmunity basis** ==================================================================== **Objectives** -------------- At the completion of the modules and the assigned reading, the student should be able to: **Topic 28: Organ-specific autoimmune diseases** ================================================ **Objectives** -------------- At the completion of the modules and the assigned reading, the student should be able to: Disease Autoantibodies Observed Serological Testing Immune Mechanism Responsible for Tissue Destruction Type of hypersensitivity -------------------------------- ---------------------------------------------------------------------------------------------------------- --------------------------------------------------------------------------------------- --------------------------------------------------------------------------------------------------------------- -------------------------- Chronic Autoimmune Thyroiditis Anti-thyroglobulin, Anti-thyroid peroxidase (TPO) Enzyme immunoassay (most common), particle agglutination, indirect immunofluorescence Thyroid infiltrated by lymphocytes, macrophages, and plasma cells; Tc destruction of thyroid epithelial cells Type IV hypersensitivity Grave\'s Disease Anti-TSH receptor (Anti-TSH-R) Usually not serological; T3, T4, and TSH assays performed Antibody mimics TSH, acting as a receptor ligand, stimulating excessive secretion of T3 and T4 Not Addison\'s Disease Anti-21-hydroxylase antibody No serological testing; chemistry tests for elevated serum ACTH and plasma renin Autoantibodies destroy adrenal cortex Type II hypersensitivity Type 1 Diabetes Mellitus Anti-GAD (glutamic acid decarboxylase), Anti-IA-2 (tyrosine phosphatase protein), IAA (insulin antibody) No serological testing; fasting hyperglycemia and elevated hemoglobin A1C Autoimmune Tc destruction of pancreatic beta cells that secrete insulin Type IV hypersensitivity **Topic 29: Systemic (\~Rheumatologic) autoimmune diseases** ============================================================ **Objectives** -------------- At the completion of the modules and the assigned reading, the student should be able to: