This study shows the evolution of the humoral immune response from IgM to IgG DSA posttransplant. We found that development of IgM persistent IgG3 positive DSA identifies the most dangerous IgG DSA subpopulation.

Post-transplant BKPyV viremia and preemptive immunosuppression reduction is associated with high rates of dnDSA. When preemptively treating BKPyV viremia, dnDSA should be monitored to prevent allograft consequences.

Imlifidase is a cysteine proteinase which specifically cleaves IgG, inhibiting Fc‐mediated effector function within hours of administration. Imlifidase converts a positive crossmatch to a potential donor (T cell, B cell, or both), to negative, enabling transplantation to occur between previously HLA incompatible donor‐recipient pairs. To date, 39 crossmatch positive patients received imlifidase prior to a kidney transplant in four single‐arm, open‐label, phase 2 studies. At 3 years, for patients who were AMR+ compared to AMR−, death‐censored allograft survival was 93% vs 77%, patient survival was 85% vs 94%, and mean eGFR was 49 ml/min/1.73 m2 vs 61 ml/min/1.73 m2, respectively. The incidence of AMR was 38% with most episodes occurring within the first month post‐transplantation. Sub‐analysis of patients deemed highly sensitized with cPRA ≥ 99.9%, and unlikely to be transplanted who received crossmatch‐positive, deceased donor transplants had similar rates of patient survival, graft survival, and eGFR but a higher rate of AMR. These data demonstrate that outcomes and safety up to 3 years in recipients of imlifidase‐enabled allografts is comparable to outcomes in other highly sensitized patients undergoing HLA‐incompatible transplantation. Thus, imlifidase is a potent option to facilitate transplantation among patients who have a significant immunologic barrier to successful kidney transplantation. Clinical Trial: ClinicalTrials.gov (NCT02790437), EudraCT Number: 2016‐002064‐13.

Little is known about the impact of CYP3A5 polymorphisms on transplantation outcomes among African American (AA) kidney transplant recipients (KTRs). To assess this issue, clinical outcomes were compared between AA CYP3A5*1 expressers and nonexpressers. This retrospective cohort study analyzed AA KTRs. Biopsy-proven acute rejection (BPAR), delayed graft function (DGF), glomerular filtration rate (GFR), infections, and tacrolimus dosing requirements were examined in 106 immunologically high-risk AA kidney transplant patients over a 2-year follow-up period. In CYP3A5*1 expressers compared to nonexpressers, the incidence of BPAR was significantly higher in the first 6 months (13% vs 0%; P = .016) compared to 24 months (13% vs 7%; P = .521). Tacrolimus total daily dose at first therapeutic level was significantly higher in CYP3A5*1 expressers (12 mg/day) compared to nonexpressers (8 mg/day; P < .001). Compared to CYP3A5*1 nonexpressers, DGF incidence was significantly higher among CYP3A5*1 expressers (27.6% vs 6.7%; P = .006). By contrast, median GFR was significantly higher in CYP3A5*1 expressers compared to nonexpressers (54.5 mL/min vs 50.0 mL/min; P = .003) at 24 months. The findings from this retrospective study suggest that AAs with CYP3A5*1 expression require 50% more tacrolimus and have an increased incidence of DGF and acute rejection.

Despite advances in the field of transplantation, immunosuppressant medication nonadherence (NA) remains a primary contributor to suboptimal long-term outcomes. Due to the multidimensional and multifactorial causes of medication NA, studies to date have focused on individual differing facets or single point barriers of NA with relative success. However, these successes have not proven to be sustainable, partly due to the intense resources needed for continued viability. This article provides a summary of a 2-day meeting held in April 2017 (Chicago, IL) prior to the American Transplant Congress in which a multidisciplinary group convened to identify the unmet research needs related to medication NA in transplantation. Thought leaders in the field presented the past, present, and future directions of medication NA with the primary outcome of designing, developing, and ranking targeted interventions into a dynamic research agenda to identify which interventions maintained effects over time. Break-out sessions were created based on the five World Health Organization (WHO) dimensions of adherence. Participants were then organized into the newly formed AST Transplant Pharmacy Adherence Consortium (AST TPAC) research group. This meeting report summarizes the content of the symposium, and the development, background, and future directions of the AST TPAC.

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Transplant immunosuppressants are often used off-label because of insufficient randomized prospective trial data to achieve organ-specific US Food and Drug Administration (FDA) approval. Transplant recipients who rely on Medicare Part D for immunosuppressant drug coverage are vulnerable to coverage denial for off-label prescriptions, unless use is supported by Centers for Medicare & Medicaid Services (CMS)-approved compendia. An integrated dataset including national transplant registry data and 3 years of dispensed pharmacy records was used to identify the prevalence of immunosuppression use that is both off-label and not supported by CMS-approved compendia. Numbers of potentially vulnerable transplant recipients were identified. Off-label and off-compendia immunosuppression regimens are frequently prescribed (3-year mean: lung 66.5%, intestine 34.2%, pancreas 33.4%, heart 21.8%, liver 16.5%, kidney 0%). The annual retail cost of these at-risk medications exceeds $30 million. This population-based study of transplant immunosuppressants vulnerable to claim denials under Medicare Part D coverage demonstrates a substantial gap between clinical practice, current FDA approval processes, and policy mandates for pharmaceutical coverage. This coverage barrier reduces access to life-saving medications for patients without alternative resources and may increase the risk of graft loss and death from medication nonadherence.

No abstract