Supplementary Material for: Plasma Exchange as an Adjunctive Therapy for Crescentic IgA Nephropathy
Background: Crescentic IgA nephropathy (CreIgAN) has a poor prognosis despite aggressive immunosuppressive therapy. The efficacy of plasma exchange (PE) in CreIgAN is not well defined. Methods: Twelve patients with severe CreIgAN who received PE as addition to routine immunosuppressive therapy, followed for more than 6 months, were involved. Twelve matched historical controls who received immunosuppressive therapy alone were selected by propensity score matching. Renal survival, plasma IgA-IgG complex and active complement products were assessed. Results: Nine men and 3 women received a median of 7 PE courses (range 5-10). Their baseline urine protein excretion rate was 5.8 (4.5-8.7) g/day, and their serum creatinine level was 705.3 ± 296.4 μmol/l. During a mean follow-up of 15.6 months (6-51 months), 6 of the 12 PE group patients were free of dialysis, while all the control patients were dialysis dependent (6 of 12 vs. 0 of 12, p = 0.014). In the PE group, dialysis had to be restarted for 1 patient owing to the development of severe pneumonia and pulmonary failure. PE was associated with a higher kidney survival rate (log rank test, p = 0.026) during follow-up. It also significantly decreased plasma IgA-IgG complex levels (pre-PE: 85.3 ± 25.9% vs. post-PE: 38.4 ± 12.4%, p < 0.001) and plasma and urinary active complement product levels, including C3a, C5a and soluble C5b-9. The latter levels remained low until the last follow-up. Conclusion: This study indicated that PE could increase renal recovery rates in severe CreIgAN.