Relationship between anti-GBM antibodies and kidney outcomes in patients with anti-GBM disease

Introduction Animal experiments have shown that anti-GBM antibodies play a pathogenic role in anti-GBM disease. However, the relationship between anti-GBM antibody levels and kidney outcomes in patients with anti-GBM disease is unclear. Methods We performed a retrospective analysis of 110 patients diagnosed with anti-GBM disease. We compared their baseline characteristics stratifying on different anti-GBM antibody levels, and used Cox regression analysis to analyze the correlation between antibody levels and kidney survival. We further selected 69 patients to evaluate the modification of antibody titers over 14 days of treatment, then compared kidney survival of patients in the group with antibody level decrease < 48% to those with antibody decrease ≥ 48%. Results The 110 patients had a median follow-up of 27.1 (Q1–Q3: 7.9–80.1) months, and among them 90 (81.8%) developed kidney failure. Multivariate analysis suggested that anti-GBM antibody level was an independent risk factor for progression to kidney failure in patients with anti-GBM disease (HR 1.08, 95% CI 1.01–1.16). The patients who reduced the antibodies levels quickly had better kidney survival than those who did not, and multivariate analysis also indicated that antibody decrease rate was related to kidney outcomes. Conclusions Anti-GBM antibody level is closely related to kidney outcomes in patients with anti-GBM disease, and short-term reduction of antibodies can be beneficial to improving kidney outcomes. Graphical abstract