In a case of undifferentiated arthritis, presence of anti-cyclic citrullinated peptide (anti CCP) indicates strong possibility of which of the following?: (A) Rheumatoid arthritis, (B) Systemic lupus erythematosis, (C) Mixed connective tissue disorder, (D) Reactive arthritis
Answer is A. Anticitrullinated peptide antibody test (Anti ccp) test is more specific than rheumatoid factor for diagnosis of rheumatoid arthritis. It may be positive very early in the course of the disease.