Identification of Antibodies to DQβ:DRα Interisotypic Heterodimers in Human Sera.

Background: HLA class II antigens, DR, DQ, and DP, comprised an α and β chains, which typically combine, within the same isotype, to form the major histocompatibility complex:peptide complex. Interisotypic pairing is not commonly observed. Although reports of DQβ:DRα heterodimers exist, the pairing was reported to be unstable and, therefore, not studied to any extent.

HLA class I peptide polymorphisms contribute to class II DQβ0603:DQα0103 antibody specificity.

Antibodies reactive to human leukocyte antigens (HLA) represent a barrier for patients awaiting transplantation. Based on reactivity patterns in single-antigen bead (SAB) assays, various epitope matching algorithms have been proposed to improve transplant outcomes. However, some antibody reactivities cannot be explained by amino acid motifs, leading to uncertainty about their clinical relevance.

Monitoring cell-mediated immunity during immunosuppression reduction in heart transplant recipients with severe systemic infections.

Background: Treatment for severe systemic infections in heart transplantation is reduction in immunosuppression while treating the infection. An assay that measures adenosine triphosphate production in activated lymphocytes (ImmuKnow ) objectively monitors cellular immunity of transplant recipients. In this study, we used ImmuKnow to adjust immunosuppression in heart transplant recipients with severe systemic infections.

Outcomes in highly sensitized pediatric heart transplant patients using current management strategies.

Background: Previous studies have suggested that children with pre-formed anti-HLA antibodies (PRA) undergoing orthotopic heart transplantation (OHT) have increased risk for rejection, coronary artery vasculopathy (CAV) and death. In 2005, our program started utilizing aggressive desensitization (including plasmapheresis, IVIg, pulse cytoxan and rituximab) with the goal of improving outcomes for these patients. The purpose of this study was to compare outcomes with this new strategy in recipients with pre-OHT high PRA (>10%) vs low PRA ≤10%).

Management of children undergoing cardiac transplantation with high Panel Reactive Antibodies.

Highly sensitised children in need of cardiac transplantation have overall poor outcomes because of increased risk for dysfunction of the cardiac allograft, acute cellular and antibody-mediated rejection, and vasculopathy of the cardiac allograft. Cardiopulmonary bypass and the frequent use of blood products in the operating room and cardiac intensive care unit, as well as the frequent use of homografts, have predisposed potential recipients of transplants to allosensitisation. The expansion in the use of ventricular assist devices and extracorporeal membrane oxygenation has also contributed to increasing rates of allosensitisation in candidates for cardiac transplantation.

Donor-specific antibody against denatured HLA-A1: clinically nonsignificant?

Pre-transplant screening of a woman with end-stage renal disease (ESRD) showed no anti-human leukocyte antigen (HLA) alloantibodies by anti-human globulin-complement-dependent cytotoxicity (AHG-CDC; class I) or enzyme-linked immunosorbent assay (class II). Following a negative AHG-CDC crossmatch, an HLA*01:01+ deceased donor (DD) kidney was transplanted in September 2005. Subsequent screening of pre-transplant serum by LABScreen Single Antigen (SA) array showed strong reactivity versus A*01:01.

The acceptable reactive crossmatch (ARC), post-transplant monitoring, and their impact on kidney transplantation: a single center experience.

Although the adverse allograft outcomes associated with HLA antibodies are well documented, some controversy exists regarding the importance of low-level donor specific anti-HLA antibodies (DSA). To provide further detail on this controversy, we prospectively looked at low-level DSA in negative T- and B-cell flow cytometric crossmatch (FCXM) or acceptable reactive crossmatch (ARC) patients who each underwent protocol based post-transplant antibody monitoring. HLA Class I and II antibody screening and specificity determination was conducted via a solid phase assay (SPA) and FCXM versus donor and autologous T and B cells.

Assessing relative risks of infection and rejection: a meta-analysis using an immune function assay.

Background: Long-term use of immunosuppressants is associated with significant morbidity and mortality in transplant recipients. A simple whole blood assay that has U.S.

Sensitization of renal transplant candidates by cryopreserved cadaveric venous or arterial allografts.

Background: Cryopreserved cadaveric venous or arterial allografts are used in ESRD patients as an alternative to synthetic grafts for hemodialysis access. We evaluated the effect of these allografts on the PRA against HLA class I and II antigens in 11 ESRD patients awaiting a kidney transplant.

Methods: Flow Cytometry using purified antigen coated beads (Flow PRA Beads) was used to determine PRA against HLA class I and II antigens.