ANCA AND PREDICTING RELAPSE IN SYSTEMIC VASCULITIS

We studied 60 patients with ANCA-positive systemic vasculitis (SV) to assess the prognostic significance of clinical and serological feature s at presentation, and the value of sequential monitoring of ANCA, C-r eactive protein (CRP) and ESR levels as predictors of disease relapse. Patients were recruited at the time of diagnosis, treated with a stan dard protocol, and assessed monthly for one year. Clinical remission w as achieved in 56/60 (93%), and ANCA became undetectable in 50/60 (83% ) after treatment. During the one year follow-up period, disease relap ses were seen in 23 (38%) patients. No specific associations were obse rved between initial disease presentation, initial ANCA level or ANCA antigenic specificity and relapse. However, 13/23 (57%) of relapses we re preceded by a rise in ANCA a mean of 7.8 weeks earlier, while at th e time of relapse 19/23 (83%) were ANCA-positive. Rises in CRP and ESR occurred in 23/60 (38%) and 14/43 (33%), respectively, but were less closely associated with relapse than ANCA. A sustained rise in ANCA wa s seen in six patients without relapse while clinical relapse occurred with a negative ANCA in four. Sequential ANCA monitoring at monthly i ntervals during disease remission is of value, at least during the fir st year, in the prediction and diagnosis of relapse in SV, and is supe rior to measurement of CRP or ESR.