The impact of intravenous methylprednisolone pulses on renal survival in anti-neutrophil cytoplasmic antibody associated vasculitis with severe renal injury patients: a retrospective study

Background: High-dose methylprednisolone pulses were one of the main treatments for anti-neutrophil cytoplasmic autoantibody (ANCA) associated vasculitides (AAV) but had obvious side effects. We aimed to know the impact on renal survival and identify the prognostic factors of this treatment in Chinese AAV patients with severe renal involvement. Methods: One hundred and eleven AAV patients with an estimated glomerular filtration rate (eGFR) of 10ml/min/1.73 m(2) or less at admission were included. The MP group (n = 57) received intravenous methylprednisolone 500 mg/d for 3 days, while the control group (n = 54) had not. The outcomes and adverse events between two groups were compared. Besides, predictors for dialysis independence and good response of intravenous methylprednisolone were analyzed using Cox regression analysis and ROC curves respectively. Results: Their median duration of follow-up was 31 (range 3 to 134) months. Eleven patients in MP group and 20 patients in control group were died (P = 0.056). Twenty-one patients (36.8%) in MP group and 29 patients (53.7%) in control group were on maintaining dialysis (P = 0.088). Twenty-one patients in MP group remained dialysis independent, more than those in control group (4 patients, P < 0.01). Urine protein creatinine ratio (hazard ratio 1.730, 95% confidence interval 1.029 to 2.909, P = 0.039) and the treatment of intravenous methylprednisolone pulses (hazard ratio 0.362, 95% confidence interval 0.190 to 0.690, P = 0.002) were the independent risk factors for dialysis independence. Those patients with serum creatinine >= 855 mu mol/L and urine protein >= 3.7g/24h at admission may have worse responses to intravenous methylprednisolone pulses (sensibility 56.7%, specificity 85.0%, PPV 100.0% and NPV57.1%). Conclusions: Intravenous methylprednisolone pulses could improve the long-term outcome in term of dialysis independence and tend to decrease mortality for Chinese AAV patients with severe renal involvement.