Emerging role of B cells in chronic allograft

Department of Anatomia Patolo´gica, Ospedale Pediatrico Bambino Gesu`, Rome, ItalyB cells have many possible mechanisms by which they canaffect allograft survival, including antigen presentation,cytokine production, immune regulation, and differentiationinto alloantibody-producing plasma cells. This report reviewsthe last mechanism, which the authors regard as most criticalfor the long-term survival of allografts, namely, thepromotion of chronic rejection by alloantibodies. Chronichumoral rejection characteristically arises late aftertransplantation and causes transplant glomerulopathy,multilamination of peritubular capillary basementmembranes, and C4d deposition in PTCs and glomeruli.Circulating antidonor human leukocyte antigen class IIantibodies are commonly detected and may precede thedevelopment of graft injury. Prognosis is poor, especiallywhen recognized after graft dysfunction has developed.Improved detection and treatment are critically neededfor this common cause of late graft loss.