Supplementary Materials Supplementary Data supp_62_5_1656__index. improved islet cell transplant outcomes. The setting of islet transplantation is interesting because both allogenic rejection and recurrence of autoimmunity may occur and affect graft survival. Histological evidence of these mechanisms is Cisplatin inhibition extremely rare (1,2) because obtaining biopsy specimens from transplanted human islets is difficult (3). Consequently, surrogate markers of allo- and autoimmunity are used to evaluate the adaptive immune response of islet graft recipients (4). Poor islet transplant outcome is associated with the presence of pretransplant autoreactive T cells (5C7) and pretransplant or Cisplatin inhibition de novo donor-specific cytotoxic and CD4+ T cells (7C11). This evidence from monitoring cellular immunity strongly suggests that long-term clinical outcome after islet transplantation is hampered by rejection, recurrence of autoimmunity, or both. Although compelling, the practical aspects of monitoring cellular immunity after islet transplantation is challenging. Monitoring of humoral immunity is easier and has now been validated for both alloimmunity (12C14) and islet autoimmunity (15). It is largely accepted that preformed pretransplant autoimmune antibodies only weakly predict posttransplant outcome (5,16C19), whereas preformed alloreactive antibodies are an important negative predictor of islet transplant outcome (20). On the other hand, the relevance of posttransplant de novo autoantibodies (19) and de novo donor-specific alloantibodies (DSA) (11,20C22) to islet transplant outcome is still unclear. In this study, we analyzed a cohort of 59 consecutive transplant recipients in which baseline and de novo posttransplant allo- and autoantibodies were measured prospectively and frequently and show the relevance of de novo responses to transplant outcome. RESEARCH DESIGN AND METHODS Islet transplant patients and baseline characteristics. Between February 2001 and March 2011, 49 nonuremic patients with type 1 diabetes (islet transplantation alone), 7 Cisplatin inhibition patients with type 1 diabetes who had a successful kidney transplant (islet after kidney transplantation), and 3 uremic patients with type 1 diabetes receiving a simultaneous kidney transplantation (simultaneous islet-kidney transplantation) received an islet transplantation under different immunosuppression regimens. Twenty-seven patients received anti-CD25 monoclonal antibody (mAb) induction and tacrolimus/sirolimus (SIR) immunosuppression (Edmonton protocol) (23), 12 were treated with a calcineurin inhibitor (CNI)-free protocol (induction of antithymocyte globulin [ATG] 1.5 mg/kg for 4 days starting at day ?1 and immunosuppression with SIR/mycophenolate mofetil [MMF]) (clinical trial reg. no. NCT01346085), and 20 were treated with an SIR-free protocol (ATG or anti-CD25 mAb induction and tacrolimus/MMF immunosuppression). Seventeen patients (nine Edmonton protocol and eight CNI-free protocol) received rapamycin 0.1 mg/kg monotherapy for at least 30 days (target trough levels 8C10 ng/mL, range 26C314 days) as preconditioning for islet transplantation (24). All islet transplantations were performed at Flt3l the San Raffaele Scientific Institute in Milan, Italy. In all cases, the patients had a negative complement fixing lymphocyte crossmatch against recipient cells. All patients signed informed consent before enrollment in the islet transplantation program. The ethics committee of the San Raffaele Scientific Institute approved the protocols. HLA typing. Genomic HLA typing was carried out with PCR sequence-specific primer (Invitrogen, Madison, WI) and reverse dot blot bead array (One Lambda, Inc., Canoga Park, CA) (25), with DNA isolated Cisplatin inhibition through the Maxwell 16 Blood DNA Purification System and stored at ?70C until testing. HLA-A, -B, and -DR mismatches were calculated by measuring the total number of mismatches to HLA-A, -B and -DR. Cw and DQB1 typing were available but are not traditionally used in documenting HLA mismatches. A number of the islet recipients received more than one infusion or an infusion from two donors at once, with maximum exposure to islets from four donors. Therefore, the maximum number of HLA mismatches was 24 (8 HLA-A, 8 HLA-B, and 8 HLA-DR). If an.