Description
4.11 Antibody Review
Rheumatology review for the USMLE Step 1 Exam.
ANA Principles
ANA (Anti-Nuclear Antibody): Non-specific antibody. Reacts against nuclear antigens, including proteins, DNA, RNA, and nucleic acid-protein complexes. Includes a group of antibodies such as anti-dsDNA, anti-histone, SSA/Ro, SSB/La, Scl-70, anti-aminoacyl-tRNA synthetase (Jo-1). Found in 20-30% of the general public without connective tissue disorder symptoms. ANA+ individuals may or may not have a rheumatologic disorder. Further workup is needed in ANA+ cases to determine the specific disorder. Antibodies by Disease Process
Systemic Lupus Erythematosus (SLE)
Anti-dsDNA antibody. Anti-Smith antibody. Drug-Induced Lupus
Anti-histone antibody. Diffuse vs. Limited Scleroderma
Diffuse: Anti-Scl-70 (anti-topoisomerase I). Limited: Anti-centromere (often called CREST syndrome, with CREST standing for centromere). Sjogren's Syndrome
Anti-SSA (Ro). Anti-SSB (La), which usually occurs in the presence of SSA. SSA is considered the Sjogren-specific antibody, leading to the presence of SSB. Rheumatoid Arthritis (RA)
Anti-CCP (Cyclic Citrullinated Peptide). RF (Rheumatoid Factor) is non-specific. Thanks for listening!
4.10 Gout and Pseudogout
Rheumotology review for the USMLE Step 1 Exam.
Gout
Caused by uric acid crystal deposition due to purine metabolism. Triggers inflammation when crystals precipitate in cooler joint fluid. Presents with severe, red, and swollen monoarticular joints, often in the big...
Published 11/08/23
4.09 Rheumatologic Emergencies
Rheumatology review for USMLE Step 1 Exam
Giant Cell Arteritis (GCA)
A large vessel vasculitis, mainly in older individuals. Symptoms: headache, jaw claudication, vision loss. Ischemia from granulomas in large vessels causes vision loss. Immediate high-dose...
Published 11/01/23