CD40LG and autoimmune disease: The proposed mechanism is through basement membrane deposition of immune complexes, predominantly IgG and C1q, which leads to a diffuse glomerular capillary leak, non-selective proteinuria, and reduced renal function [6]. In this case, IgG and C1q deposition is observed, further differentiating it from autoimmune diseases like lupus, which present with deposition of IgA, IgG, IgM, C3, and C1q.