Abstract: 【Abstract】Objective This study aimed to analyze the clinical features of anti-GBM patients with the treatment of plasmapheresis and to address the effect of plasmapheresis on removing circulating anti-GBM antibodies and on renal survival. Methods Sixty patients with anti-GBM disease in our department were enrolled, and all of whom received more than one session of plasmapheresis. The clinical features and the levels of anti-GBM antibodies before and after plasmapheresis were collected. Results ①After plasmapheresis, circulating anti-GBM antibodies disappeared in 33/60 (55%) patients. Patients with negative circulating anti-GBM antibodies after plasmapheresis had a significantly lower level of initial anti-GBM antibodies on diagnosis (123.00 vs. 200.00 RU/ml, Z=-3.976, P＜0.001) and a higher proportion of receiving intravenous pulse methylprednisolone (61.70% vs. 30.80%, χ2=3.937, P=0.047), compared to those who still had detectable circulating antibodies after plasmapheresis. The level of anti-GBM antibodies on diagnosis was the independent risk factor for antibody persistence after plasmapheresis (OR 7.727, 95% CI 1.911～31.240, P=0.004). ②In the present study, 38/60 (63.30%) patients progressed to end- stage renal disease (ESRD). They presented higher levels of serum creatinine (Z=-2.454, P＜0.001) and anti-GBM antibodies on diagnosis (Z=-2.089, P=0.037), a higher proportion of oliguria/anuria (χ2=6.334, P=0.012) and a lower proportion of antibody disappearance after plasmapheresis (χ2=6.962, P=0.008), compared to the patients without ESRD. There was no significant difference in the number of plasmapheresis sessions between patients with and without ESRD (Z=-1.534, P=0.125). Logistic regression model showed that renal survival was only predicted by serum creatinine (>600μmol/L) on diagnosis (OR 13.824, 95% CI 2.332～81.939, P=0.004). Conclusions Circulating anti-GBM antibodies could be efficiently removed by plasmapheresis. The level of anti-GBM antibodies on diagnosis was the independent risk factor for antibody persistence after plasmapheresis. Renal survival was predicted by serum creatinine (>600μmol/L) on diagnosis, but had no significant correlation with the number of plasmapheresis sessions.

Key words: anti-glomerular basement membrane antibody, plasmapheresis, renal prognosis