Pretransplant Immune Parameters Associate With Islet Allograft Outcome Implications for Transplant Strategy?

Extensive and informative immunological assess-ments of islet transplant recipients have beenlimited due, in part, to the smaller numbers ofpatients transplanted compared with solid or-gan trials. Limitations related to blood volume and the logistical challenges of collecting multiple posttransplant samples for drug levels as well as clinical and metabolic parameters also pose challenges. Several variables affect islet allograft outcome, including allo- and autoimmune responses to transplanted islets, -cell mass and islet quality, efficacy of the immunosuppressive regimen and its effect on islet function, as well as glycemic control. In fact, much debate has centered on whether or not islet attrition is due to immune-mediated loss, death of overworked cells caused by insufficient mass, and/or diabetogenic effect of various immune intervention agents. In addi-tion, many of these parameters may have differing effects based on the transplanted mass, with margina