THE CLINICAL AND DIAGNOSTIC VALUE OF ANTI-CYCLIC CITRULLINATED PEPTIDE ANTIBODIES IN EARLY JUVENILEARTHRITIS

Abstract

Objective: to estimate the concentration of anti-cyclic citrullinated peptide antibodies (CCPA), the frequency of their increase, and their diagnostic value in children with early juvenile arthritis (JA). Subjects and methods. Sera from 80 patients (36 girls and 44 boys) aged 1,5 to 16 years (mean age 8,5+5,03 years) who had early JA were tested for CCPA. The diagnosis of juvenile rheumatoid arthritis (JRA) and juvenile chronic arthritis (JCA) was made in 19 and 57 patients, respectively; the duration of JA being < 3 months in 4. The systemic type of JA was present in 8 (10%) children; the polyarticular and oligoar-ticular types in 37 (46,2%) and 35 (43,8%) children, respectively. The duration of the disease in all children did not exceed 6 months. A comparison group comprised 54 adult patients with early rheumatoid arthritis (RA), 27 with undifferentiated arthritis (UDA), and 37 apparently healthy children. The concentration of CCPA was measured by immunoassay using the commercial оAxis Shield Diagnosticsп kits (United Kingdom), the upper normal range being 5 U/ml. Results. The higher levels of CCPA were revealed in 7 (8,8%) children with early JA. Their frequency was higher than that in healthy children; however, it was lower than that in adult patients with RA and comparable with UDA. CCPAs were detected more frequently in JCA and rheumatoid factor (RF)-positive patients. Higher concentrations were observed in patients with RF-positive polyarticular JA. There were correlations of CCPA with the number of swollen and tender joints, RF. Conclusion. In patients with early JA, the detection rate of CCPA is significantly higher than that in healthy children and comparable with that of RF. CCPAs have a high specificity for the diagnosis of JRA (an independent nosological entity within JA) are a risk factor of polyarthritis. The early detection of CCPA alone or in combination with RF in JA patients may serve the basis for the early use of active, frequently aggressive therapy.