PREVALENCE OF ANTINEUTROPHIL CYTOPLASMIC ANTIBODIES (ANCA) IN JUVENILE CHRONIC ARTHRITIS

Objective. Sera from 66 children with active JCA of oligoarticular, po lyarticular or systemic onset, 13 sera from patients in disease remiss ion, 15 sera from patients with reactive arthritis, and 11 from Lyme a rthritis patients were tested for the presence of anti-neutrophil cyto plasmic antibodies (ANCA) in order to evaluate their diagnostic signif icance in JCA. Results. ANCA were found in 21% (14/66) of the active J CA sera, all showing an atypical pANCA staining pattern using indirect immunofluorescence on ethanol fixed granulocytes. 71% of these sera a lso showed antinuclear antibodies (ANA) on HEp-2 cells. By additional staining on paraformaldehyde fixed granulocytes to exclude staining ar tefacts due to ethanol fixation 2 of the pANCA positive sera showed cy toplasmic staining. In no case did we find nuclear fluorescence sugges ting a true cytoplasmic localization of the involved antigens. All ANC A positive sera were negative for anti-MPO and anti-LF antibodies. ANC A prevalence in our study group did not correlate with the disease sub group, disease duration or other clinical characteristics. However, we found ANCA only in active disease. Conclusion. Our data suggest that the diagnostic importance of ANCA in JCA is restricted to only a few J CA patients. In these cases, however, ANCA positivity supports the dia gnosis of JCA. Further studies ave needed to substantiate this finding , as well as possible subgroup specificities. Standardized techniques of granulocyte fixation and antigen specific tests are needed to produ ce comparable results in different study groups.