Abstract：
IgA nephropathy (IgAN), which has been confirmed as a complement mediated autoimmune disease, is also one form of glomerulonephritis associated with COVID-19. Here, we aim to investigate the clinical and immunological characteristics of patients with IgAN after COVID-19. The level of plasma level of C5a (p < 0.001), soluble C5b-9 (p = 0.018), FHR5 (p < 0.001) were all significantly higher in Group CoV (33 patients with renal biopsy-proven IgAN experienced COVID-19) compared with Group non-CoV (44 patients with IgAN without COVID-19), respectively. Compared with Group non-CoV, the intensity of glomerular C4d (p = 0.017) and MAC deposition (p < 0.001) and Gd-IgA1 deposition (p = 0.005) were much stronger in Group CoV. Our finding revealed that for IgAN after COVID-19, mucosal immune responses to SARS-CoV-2 infection may result in the overactivation of systemic and renal local complement system, and increased glomerular deposition of Gd-IgA1, which may lead to renal dysfunction and promote renal progression in IgAN patients.
摘要：
IgA肾病(IgAN),已被证实为补体介导的自身免疫性疾病，也是与COVID-19相关的肾小球肾炎的一种形式。这里,我们的目的是探讨COVID-19后IgAN患者的临床和免疫学特征。血浆C5a水平（p<0.001），可溶性C5b-9（p=0.018），与非CoV组（44例无COVID-19的IgAN患者）相比，CoV组（33例经肾活检证实的IgAN患者出现COVID-19）的FHR5（p<0.001）均显着高于非CoV组，分别。与非CoV组相比，CoV组肾小球C4d（p=0.017），MAC沉积（p<0.001）和Gd-IgA1沉积（p=0.005）的强度更强。我们的发现表明，对于COVID-19后的IgAN，对SARS-CoV-2感染的粘膜免疫反应可能导致全身和肾脏局部补体系统过度激活，肾小球Gd-IgA1沉积增加，可能导致IgAN患者肾功能不全，促进肾脏进展。
