Plasma exchange for renal vasculitis and idiopathic rapidly progressive glomerulonephritis: a meta-analysis

Background: Plasma exchange may be effective adjunctive treatment for renal vasculitis. We performed a systematic review and meta-analysis of randomized controlled trials of plasma exchange for renal vasculitis.

Study design: Systematic review and meta-analysis of articles identified from electronic databases, bibliographies, and studies identified by experts. Data were abstracted in parallel by 2 reviewers.

Setting & population: Adults with idiopathic renal vasculitis or rapidly progressive glomerulonephritis.

Selection criteria for studies: Randomized controlled trials that compared standard care with standard care plus adjuvant plasma exchange in adult patients with either renal vasculitis or idiopathic rapidly progressive glomerulonephritis.

Intervention: Adjuvant plasma exchange.

Outcome: Composite of end-stage renal disease or death.

Results: We identified 9 trials including 387 patients. In a fixed-effects model, the pooled RR for end-stage renal disease or death was 0.80 for patients treated with adjunctive plasma exchange compared with standard care alone (95% CI, 0.65-0.99; P = 0.04). No significant heterogeneity was detected (P = 0.5; I(2) = 0%). The effect of plasma exchange did not differ significantly across the range of baseline serum creatinine values (P = 0.7) or number of plasma exchange treatments (P = 0.8). The RR for end-stage renal disease was 0.64 (95% CI, 0.47-0.88; P = 0.006), whereas the RR for death alone was 1.01 (95% CI, 0.71-1.4; P = 0.9).

Limitations: Although the primary result was statistically significant, there is insufficient statistical information to reliably determine whether plasma exchange decreases the composite of end-stage renal disease or death.

Conclusions: Plasma exchange may decrease the composite end point of end-stage renal disease or death in patients with renal vasculitis. Additional trials are required given the limited data available.