Supplementary Material for: Plasma Exchange as an Adjunctive Therapy for Crescentic IgA Nephropathy

<b><i>Background:</i></b> Crescentic IgA nephropathy (CreIgAN) has a poor prognosis despite aggressive immunosuppressive therapy. The efficacy of plasma exchange (PE) in CreIgAN is not well defined. <b><i>Methods:</i></b> 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. <b><i>Results:</i></b> 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 &lt; 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. <b><i>Conclusion:</i></b> This study indicated that PE could increase renal recovery rates in severe CreIgAN.<br>

<b><i>背景：</i></b> 尽管采取强化免疫抑制治疗，新月体性IgA肾病（Crescentic IgA nephropathy，CreIgAN）的预后仍较差，而血浆置换（plasma exchange，PE）用于CreIgAN的疗效尚未明确。
<b><i>方法：</i></b> 本研究纳入12例重度CreIgAN患者，在常规免疫抑制治疗基础上加用PE，随访时长均超过6个月；同时通过倾向得分匹配法选取12例仅接受免疫抑制治疗的匹配历史对照患者。本研究评估了肾脏存活率、血浆IgA-IgG复合物及活性补体产物水平。
<b><i>结果：</i></b> 该研究组共9名男性、3名女性患者，中位接受7次PE疗程（范围5~10次）；患者基线尿蛋白排泄率为5.8（4.5~8.7）g/天，血清肌酐水平为705.3±296.4 μmol/L。在平均15.6个月（6~51个月）的随访期间，PE组12例患者中有6例无需透析，而对照组所有12例患者均依赖透析（6/12 vs 0/12，p=0.014）。PE组中有1例患者因出现重症肺炎及呼吸衰竭需重启透析。随访期间，PE组患者的肾脏存活率更高（对数秩检验，p=0.026）；同时PE可显著降低血浆IgA-IgG复合物水平（PE前：85.3±25.9% vs PE后：38.4±12.4%，p<0.001），以及血浆和尿液中的活性补体产物水平，包括C3a、C5a及可溶性C5b-9；上述补体产物水平在末次随访时仍维持在较低水平。
<b><i>结论：</i></b> 本研究结果表明，PE可提升重度CreIgAN患者的肾脏康复率。