Low Serum Complement C3 Levels at Diagnosis of Renal ANCA-Associated Vasculitis Is Associated with Poor Prognosis.

BACKGROUND: Recent studies have demonstrated the key role of the complement alternative pathway (cAP) in the pathophysiology of experimental ANCA-associated vasculitis (AAV). However, in human AAV the role of cAP has not been extensively explored. In the present work, we analysed circulating serum C3 levels measured at AAV onset and their relation to outcomes. METHODS: We conducted a retrospective observational cohort study including 45 consecutive patients with AAV diagnosed between 2000 and 2014 with serum C3 measurement at diagnosis, before immunosuppressive treatment initiation. Two groups were defined according to the median serum C3 level value: the low C3 group (C3<120 mg/dL) and the high C3 level group (C3≥120 mg/dL). Patient and renal survivals, association between C3 level and renal pathology were analysed. RESULTS: Serum complement C3 concentration remained in the normal range [78-184 mg/dL]. Compared with the high C3 level, the patients in the low C3 level group had lower complement C4 concentrations (P = 0.008) and lower eGFR (P = 0.002) at diagnosis. The low C3 level group had poorer patient and death-censored renal survivals, compared with the high C3 level group (P = 0.047 and P = 0.001, respectively). We observed a significant negative correlation between C3 levels and the percentage of glomeruli affected by cellular crescent (P = 0.017, r = -0.407). According to the Berden et al renal histologic classification, patients in the crescentic/mixed category had low C3 levels more frequently (P<0.01). Interestingly, we observed that when patients with the crescentic/mixed histologic form were analysed according to C3 level, long term renal survival was significantly greater in the high C3 level group than in the low C3 level group (100% vs 40.7% at 6 years, p = 0.046). No relationship between serum C4 and renal outcome was observed. CONCLUSION: A Low C3 serum level in AAV patients at diagnosis is associated with worse long-term patient and renal survival.

Addition of plasma exchange to glucocorticosteroids for the treatment of severe Henoch-Schönlein purpura in adults: a case series.

BACKGROUND: Adult Henoch-Schönlein purpura (HSP) has been associated with poor outcome and end-stage renal disease in >20% of cases. Although the benefit of adding another immunosuppressant to steroids in severe adult HSP has not been shown, the benefit of plasma exchange (PE) therapy has been poorly evaluated. STUDY DESIGN: Case series. SETTING & PARTICIPANTS: 11 consecutive patients with severe and newly diagnosed HSP since 1988 who were treated with steroids and PE. OUTCOME & MEASUREMENT: Patients' characteristics and outcome were analyzed. Birmingham Vasculitis Activity Score (BVAS), estimated glomerular filtration rate (eGFR), and proteinuria were measured at baseline, at the end of PE treatment, at months 6 and 12, and at the last visit. Side effects of corticoid treatment and PE were recorded. RESULTS: 11 patients were identified in 1988-2010. Patients received intravenous corticoid pulses in 64% of cases, followed by oral prednisone for a median of 6.6 months. They received a median of 12 PE sessions. BVAS, eGFR, and proteinuria improved significantly between baseline and the last PE at a median of 2 months. PE sessions were well tolerated, except in one patient who developed central catheter-associated septicemia. One patient required dialysis therapy 15 days after HSP diagnosis and did not recover kidney function. At the last medical evaluation at a mean follow-up of 6 years, median eGFR and proteinuria were 83 ± 22 mL/min/1.73 m(2) and protein excretion of 140 ± 10 mg/d, respectively. 3 women had pregnancy without complications. LIMITATIONS: This case series did not have a control group. CONCLUSIONS: The combination of PE and corticoid therapy in severe forms of HSP was associated with fast improvement and good long-term outcome.