Solid-Phase C1q/C3d Fixing Readouts Correlate with High Median Fluorescence Intensity (MFI) De Novo Donor-Specific HLA Antibodies and C4d⁺ Antibody-Mediated Rejection in Kidney Transplant Recipients.

BACKGROUND Solid-phase assays to investigate the complement-activating capacity of HLA antibodies have been utilized to optimize organ allocation and improve transplant outcomes. The clinical utility of C1q/C3d-binding characteristics of de novo donor-specific anti-HLA antibodies (dnDSA) associated with C4d-positive antibody-mediated rejection (C4d⁺ AMR) in kidney transplants (KTx) has not been defined. MATERIAL AND METHODS Sera from 120 KTx recipients that had dnDSA concurrent with protocol/cause biopsy (median 3.

Characterization of an antibody specific for HLA-A36 and not reactive with HLA-A1.

Humoral sensitization to HLA often results in antibodies to public determinants shared among two or more antigens. Although monoclonal antibodies to A36 have been produced, there are no reports of polyclonal antibodies that react with A36 but not A1. We report here sera from a heart transplant recipient that reacted with A36 but not A1 in tests with both phenotype and single antigen panels on the Luminex platform.

Immunogenetics and immunology in transplantation.

Advances in immunogenetics and histocompatibility have facilitated the clinical transplantation of solid organs and tissues. Improved definition of HLA antigens, alleles, and haplotypes has clarified the diversity of the HLA system among different racial/ethnic populations. Knowledge of allele and haplotypes frequencies derived from these studies can be applied to the estimates of transplant compatibility and the likelihood finding suitable donors.

Reconstitution of peripheral allospecific CD19+ B-cell subsets after B-lymphocyte depletion therapy in renal transplant patients.

Background: Desensitization protocols, which frequently use lymphocyte depleting agents have increased access to successful transplantation for sensitized candidates. Here, we report on the reconstitution of human leukocyte antigen (HLA)-specific B lymphocytes in renal transplant patients after treatment with B-lymphocyte depletion.

Methods: Sixteen renal transplant candidates were included in the study.

HLA-specific B cells: II. Application to transplantation.

Background: Differences in the antibody response to allogeneic transplantation exist between groups defined by race or gender. These differences may reflect differences in immune competency and/or exposure to alloantigens. We have investigated the frequencies and phenotypes of HLA-specific B cells to address those possibilities.

HLA-specific B cells: I. A method for their detection, quantification, and isolation using HLA tetramers.

Background: The development of highly sensitive and specific assays for detecting and characterizing HLA-specific antibodies has contributed to an appreciation of the extensive involvement of those antibodies in graft injury and dysfunction. However, understanding the regulatory processes of the humoral response to transplantation and the mechanisms underlying therapeutic agents and protocols for preventing and treating sensitization requires a way to study HLA-specific B cells.

Methods: Lymphocyte preparations enriched for B cells were stained with one or more of three different HLA tetramers.

Specific and durable elimination of antibody to donor HLA antigens in renal-transplant patients.

Background: Donor-specific antibody (DSA) is the major barrier to success of kidney transplants. Attempts to deal with this problem have used plasmapheresis to remove antibodies or high-dose pooled immunoglobulin (IVIg) to down-regulate DSA. However, elimination of antibodies by these methods has been limited in duration or scope.