RESUMO
Aim: Autoantibodies against cyclic citrullinated peptide (anti-CCP) are considered to be a sensitive and specifi c marker for rheumatoid arthritis (RA). This study evaluated the diagnostic and analytical performances of the automated anti-CCP assay. Materials and Method: Sera from 80 patients with established RA, 65 from other rheumatic diseases (non-RA) and 55 from healthy controls were studied using second generation anti-CCP. Rheumatoid factor (RF) was also assayed in each sample, and the results were compared to the anti-CCP fi ndings. Serum pools were used to determine the precision and linearity. Results: At a cut-off of 7.4 U/ml for anti-CCP, the sensitivity and specifi city for RA were 65% and 98% respectively. RF had a sensitivity of 58% and a lower specifi city of 93 % than anti-CCP. Conclusion: The high specifi city of the assay suggests that anti-CCP is useful in the diagnosis of rheumatoid arthritis and in our cohort of study population anti-CCP exhibits a better diagnostic value than RF. A considerable proportion (28%) of RF-negative RA patients were anti-CCP positive. Based on analytical performance of the assay, we conclude that full automation and high throughput features of AxSYM makes it an ideal platform for routine testing of anti-CCP.
RESUMO
The diagnosis of patients with fever of unknown origin (FUO) is often problematic because the range of possible differential diagnoses is broad. We report on a case in which a patient presented with FUO and was subsequently found to have both a collagen vascular disease and an intercurrent infection. Treatment for the collagen vascular disease with corticosteroids exacerbated the intercurrent infection. The problems in the diagnosis and management of such cases are discussed.