Onset of post-transplant proteinuria, expression of SMPDL-3b in the xeno kidney grafts, and levels of anti-pig IgG and IgM. (A) Onset of 2+ proteinuria in animals treated with rituximab after xeno-kidney transplantation (KTx; red dots). (B) SMPDL-3b expression in kidney graft biopsies on POD-1 (left) and POD-27 (right). (C) Post-transplant time course of anti-pig IgG and IgM as detected by flow cytometry (upper, IgG; lower, IgM) in the treated (red line) and untreated (blue line) groups. MFI, mean fluorescence intensity.