There were 317 screened patients at the eight participating centers, and 290 were enrolled. recipients who underwent transplant with positive crossmatch, non-sensitized recipients, and sensitized recipients without positive crossmatch. Positive crossmatch recipients received antibody removal and augmented immunosuppression, while other recipients received standard Doxycycline monohydrate immunosuppression with corticosteroid avoidance. This first CTOTC-04 report summarizes study rationale and design, and reports on pre-transplant sensitization status using solid phase technology. Risk factors for sensitization were explored. Of 317 screened patients, 290 were enrolled and 240 underwent transplantation. Core laboratory Doxycycline monohydrate evaluation demonstrated that over half of patients were anti-HLA sensitized. Over 80% of sensitized patients had class I (with or without class II) HLA antibodies, and one third of sensitized patients had at least one HLA antibody with median fluorescence intensity (MFI) 8000. Logistic regression models demonstrated male sex, weight, congenital heart disease history, prior allograft and ventricular assist device are independent risk factors for sensitization. Introduction The presence of preformed antibodies specific against HLA prior to pediatric heart transplantation has been associated with high wait-list mortality, partially reflecting an historical requirement for negative donor-specific complement-dependent cytotoxicity crossmatch (CDC-XM) (1C4). By contrast, transplant across a positive CDC-XM may be associated Doxycycline monohydrate with worse outcomes due to increased rejection, graft coronary vasculopathy, graft dysfunction and failure (3, 5C8). In recent years, select centers have offered transplantation across a positive CDC-XM to sensitized candidates with high risk of pre-transplant mortality (1, 9C12). Early results have been motivating, even when retrospective CDC-XM was positive. However, ideal strategies for transplant and management of sensitized pediatric heart candidates remain unfamiliar, in part due to challenges of drawing conclusions from small numbers of subjects in single center studies. Consequently, we developed a prospective, multi-center study to assess the effect of pre-transplant sensitization on pre- and post-transplant results in pediatric heart candidates, focusing on the security and effectiveness of transplant across a positive CDC-XM and the effect of donor specific antibody (DSA) on post-transplant results. The study was developed within the infrastructure of the National Institutes of Health (NIH)Csponsored Clinical Tests in Organ Transplantation in Children (CTOTC) system (www.ctotc.org). The seeks of this 1st CTOTC-04 statement are to: 1. Describe study rationale and design; 2. Report rate of recurrence and characterize pre-transplant alloantibodies using contemporary solid phase assays; and 3. Define risk factors for sensitization in the study populace. Methods Study Design Overview This is a prospective, observational, multi-center cohort study of pediatric heart transplant candidates. The primary objective is definitely to compare medical results of sensitized recipients with positive CDC-XM at transplant (handled with a specialized treatment plan; observe below), to non-sensitized recipients, or sensitized recipients without positive CDC-XM (handled with standard immunosuppression). The primary hypothesis is definitely that highly sensitized candidates with positive CDC-XM can achieve first year results much like non-sensitized candidates when handled with perioperative antibody removal. Secondary objectives NFKBIA focused on results based on assessment of DSA, self-employed of CDC-XM results. In addition, a series of mechanistic studies was designed to evaluate graft accommodation in the establishing of circulating DSA, and for development of a biomarker for antibody-mediated rejection (AMR) based on evaluation of levels of cell-bound match activation products in peripheral blood. Full description of mechanistic studies is outside the scope of this report, and will be detailed in future publications (allo-antibody production post-transplant and assessment of the impact on graft and participant results. Specificity and time course of production of post-transplant allo-antibodies and risk factors for his or her development. Incidence of hospitalization. Incidence of severe infections. Time to analysis of chronic rejection (graft coronary artery disease). Time to post-transplantation lymphoproliferative disorders. Time to new-onset diabetes mellitus. Open in a separate window Secondary endpoints are outlined in Table 2, and are assessed at 12 months post-transplant as well as at subsequent follow-up up to three years post-transplant. Alloantibody Core Laboratory Samples of whole blood were sent at space temperature by over night courier from medical sites to the Alloantibody Core Laboratory, where Doxycycline monohydrate serum was separated, aliquoted and stored at ?80C. Specimens were analyzed for the presence of HLA antibodies using swimming pools of beads coated with purified class I or class II HLA or MICA antigens. LSM12 beads were utilized for the detection of HLA antibodies as well as antibodies to MICA, and LSA1 and LSA2 beads were utilized for class I and class II single-antigen analysis, respectively. Manufacturers positive cutoff for the percentage of LABScreen:Normalized Background (1.4) was utilized for testing. The reactions of a given HLA specificity were expressed.