IGHA1 and nephritis: Moreover, patients with IgAN had similar levels of serum Gd-IgA1 compared to first-degree relatives (SMD=0.38, 95% CI= -0.04-0.81, P=0.08) and IgA vasculitis with nephritis patients (SMD=0.12, 95% CI= -0.04-0.29, P=0.14).