Immunopathology Flashcards
Role of HLA
Role in immune response Role in organ transplantation Role in predisposition to disease
A 20-year-old woman presented with complaints of fever for 2 weeks; pleuritic chest pain; and intermittent joint pain in her hands, feet, and knees. On examination, she was free of skin lesions. She had a pleural friction rub; a slightly swollen tender right knee; and enlarged axillary, cervical, and inguinal lymph nodes. A chest film showed a small right pleural effusion; joint films were normal except for a small amount of soft tissue swelling in the right knee. Hemoglobin was 10 g/dL, and urinalysis revealed 4+ proteinuria with white blood cells, red blood cells, and red cell casts in the urine sediment. A VDRL test was positive. A test for antitreponemal antibodies was negative. Blood urea nitrogen (BUN) and creatinine were slightly elevated, and moderate hypoalbuminemia and hypergammaglobulinemia were present. An ANA test was positive at a titer of 1:2560 and was reported as showing a speckled pattern. A dsDNA antibody determination by the Crithidia luciliae assay was positive at 1:320, and an extractable nuclear antigen (ENA) antibody determination was reported as RNP (U1-RNP) and Sm antibody present. A C4 level was less than 10 mg/dL (reference range 12-45 mg/dL) and a C3 level was less than 40 mg/dL (reference range 88-192 mg/dL). The patient was treated with prednisone, 60 mg/day. After 4 weeks, the urine protein was 2+, the sediment had cleared, and BUN and serum creatinine had returned toward normal. Diagnosis?
SLE
•Class I MHC molecules are expressed on………………………………
all nucleated cells and platelets
•Class II MHC molecules are encoded in a region called….
HLA-D
•A number of autoimmune and other diseases are associated with the inheritance of ………………………
particular HLA alleles.
- a particular HLA produce diseases:
- the prevailing hypotheses implicate an auto-aggressive immune response due to an aberrant presentation of ………………………….by particular HLA molecules.
self-mimicking-, or altered self-antigens
•Class I MHC= HLA-A, HLA-B, and HLA-C
molecules display peptides such as ———————-antigens, that are located in the………………………..
viral and tumor; cytoplasm
Biopsy kidney in renal failure. H&E stain.
Possible diagnosis?
Renal Amyloidosis
Need special stain to confirm
B27 is associated with (diseases)
P A I R
DR 4 is associated with
RA, DM 1
•Disease with Antibody against a self-antigen” is called:
ANA
How these HLA genes produce autoimmunity?
- Defective tolerance or regulation.
- Abnormal display of self-antigens.
- Inflammation or an initial innate immune response.
•Polymorphisms in the gene for NOD2 are associated with…………….
Crohn disease
Polymorphisms in a gene called PTPN22: encodes a protein tyrosine phosphatase, are associated with …………………..
rheumatoid arthritis, type 1 diabetes
hidden self antigens are:
SPERMS, LENS MATERIALS
Mechanism of diseases is SLE-
mostly type III hypersensitivity
Biopsy skin rash in SLE will show (IF):
An immunofluorescence stained for IgG reveals linear deposits of
immunoglobulin along the dermal-epidermal junction.
Glomerulonephritis- Lupus nephritis is caused by…..
immune complex-mediated in the GBM (Type III)
Thrombosis ( DVT) in SLE is caused by
Anticardiolipin antibody: Antiphospholipid syndrome (APS) can occur in patients with SLE.