CD40LG and systemic lupus erythematosus: Among the known IgA or IgM mediated anti-GBM diseases, most of the patients had some immune diseases, including Henoch-Schonlein purpura, Crohn’s disease, and systemic lupus erythematosus; on the other hand, the autoantigen might prove more to be heterogeneous: it belonged to α5 and α6 chains of type IV collagen [13].