RELAPSE RATE, RENAL SURVIVAL, AND CANCER MORBIDITY IN PATIENTS WITH WEGENERS-GRANULOMATOSIS OR MICROSCOPIC POLYANGIITIS WITH RENAL INVOLVEMENT

Wegener's granulomatosis (WC) and microscopic polyangiitis (MPA) are b oth frequently associated with antineutrophil cytoplasmic autoantibodi es (ANCA). Immunosuppressive treatment has dramatically improved outco me for these patients, bur today we have to deal with the problems of relapses, cases refractory to treatment, and long-term side effects of therapy. This study comprises a consecutive series of 123 patients wi th WG (n = 56) or MPA (n = 67) with biopsy-confirmed renal involvement , followed up for a median of 55 mo (range, 0.1 to 273.2 mo). ANCA was detected by enzyme-linked immunosorbent assay in 97% of patients. Nea rly half of the patients (46%) relapsed. There was no statistically si gnificant difference in overall relapse rate according to type of ANCA . Renal survival was 78% in patients alive at the end of follow-up. Th ree variables seemed important for renal survival: serum creatinine, t he titer of proteinase 3-ANCA measured by capture enzyme-linked immuno sorbent assay, and B thrombocyte count, at time of referral. Cancer in cidence data were obtained from the population-based South Swedish Reg ional Tumor Registry. Standardized morbidity ratio was calculated usin g expected values from the health care region. We found an 11-fold inc rease in risk for bladder cancer in patients treated with cyclophospha mide for at least 12 mo. Skin carcinoma had the strongest relationship with azathioprine use for at least 12 mo and with corticosteroid ther apy for at least 48 mo. In addition, four patients developed myelodysp lastic syndrome and five had carcinoma in situ of the skin. Because th e therapeutic regimen used today is not efficient enough to prevent re lapses and is associated with a host of side effects, of which the ris k for cancer is by far the most important, improved therapy and medica l care are needed for patients with WG and MPA.