ABIM Auto-Antibodies Exam 21 Questions with Verified Answer,100% CORRECT

ABIM Auto-Antibodies Exam 21 Questions with Verified Answer ANA - CORRECT ANSWER SLE -- >95% sensitivity (also in SSc, Sjogren, MCTD) Anti-dsDNA - CORRECT ANSWER SLE -- >95% specificity, correlates with disease activity Anti-Smith - CORRECT ANSWER SLE -- most specific, 99%. But only 30% sensitive Anti-U1 RNP - CORRECT ANSWER MCTD (also in SLE) -- does not correlate with disease activity Anti-Ro (SSA) & Anti-La (SSB) - CORRECT ANSWER Sjogren syndrome (also in SLE)-- assoc with photosensitive rash. + mother increases risk for neonatal lupus erythematosus (rash and CHB) Antiribosomal P - CORRECT ANSWER SLE -- assoc with CNS lupus and lupus hepatitis Anti-Scl-70 (antitopoisomerase-1) - CORRECT ANSWER DcSSc -- assoc with pulmonary fibrosis Anticentromere - CORRECT ANSWER LcSSc (CREST) -- increases risk for pulmonary arterial hypertension c-ANCA (antiproteinase-3) - CORRECT ANSWER Granulomatosis with polyangiitis (Wegener's) -- 90% sensitivity when disease is active; high specificity in classic presentations p-ANCA (antimyeloperoxidase) - CORRECT ANSWER Microscopic polyangiitis, eosinophilic granulomatosis with polyangiitis (Churg-Strauss). Atypical can be seen in IBD and with positive ANA Anti-Jo-1 (Anti-aminoacyl-tRNA synthetase) - CORRECT ANSWER Polymyositis -- assoc with antisynthetase syndrome Rheumatoid factor - CORRECT ANSWER Rheumatoid arthritis (70% sensitivity but limited specificity), Sjögren, cryoglobulinemia Anti-cyclic citrullinated peptide - CORRECT ANSWER Rheumatoid arthritis -- 70% sensitivity, 95% specificity. Assoc with erosions; predicts disease progression in undifferentiated arthritis Antihistone - CORRECT ANSWER Drug-induced lupus -- 95% sensitivity. Can also be seen in primary SLE Cryoglobulins - CORRECT ANSWER Vasculitis; hepatitis C; myeloma; SLE; RA Anti-RNA polymerase III - CORRECT ANSWER DcSSc -- assoc with scleroderma renal crisis Anti GQ1b ganglioside protein - CORRECT ANSWER Miller-Fisher variant of Guillain-Barré syndrome Anti Muscle-specific kinase (MuSK) - CORRECT ANSWER Myasthenia gravis with weakness of cervical extension