HLA class II DQA and DQB epitopes: recognition of the likely binding sites of HLA-DQ alloantibodies eluted from recombinant HLA-DQ single antigen cell lines.

Donor-specific antibodies (DSA) in sera of sensitized transplant patients are often produced against the specific epitopes on mismatched HLA antigens. In this study, we selected sera from 30 kidney transplant patients with DSA and AMR to define DQ epitopes. Using adsorption and elution assays, we identified 18 antibody reaction patterns to define 6 new epitopes and to confirm 12 previously defined epitopes.

The role of immunoglobulin-G subclasses and C1q in de novo HLA-DQ donor-specific antibody kidney transplantation outcomes.

Background: Anti-HLA-DQ antibodies are the predominant HLA class II donor-specific antibodies (DSAs) after transplantation. Recently, de novo DQ DSA has been associated with worse allograft outcomes. The aim of this study was to determine the further complement-binding characteristics of the most harmful DQ DSA.

Effect of amino acid mismatch in the UNOS dataset.

This study began with the 2010 UNOS data-set of 181,653 deceased donor kidney transplant cases and 92,577 living donor cases. Cases with ambiguous or missing HLA typing were excluded, and the remaining cases were split into subgroups by the number of previous transplants and ethnic groups of donor-patient pairs. 41,128 Caucasian donor-patient pairs that were primary living-donor transplant cases were used as the pilot population to identify potential epitope groups that have a negative effect on graft outcome.

The HLA-matching effect in different cohorts of kidney transplant recipients: 10 years later.

Almost all the HLA-matching effects found by the 2000 analysis were confirmed by this study. The only HLA-matching effect found in the 2000 analysis that disappeared were those of "small matching effect" found in sub-populations of type I diabetes (PRA < 10%, donor age 20-35). The 2000 analysis found a lack of HLA matching effect in non-African American kidney transplant patients with type I diabetes between 1987 and 2000.

Epitopes of human leukocyte antigen class I antibodies found in sera of normal healthy males and cord blood.

This study defines 96 epitopes targeted by human leukocyte antigen (HLA) antibodies reported in the sera of normal healthy males with no history of deliberate alloimmunizations and in cord blood. These epitopes are accessible for antibody binding on either the intact or the dissociated forms of recombinant HLA class I single antigens. Sixty percent of the epitopes are accessible on dissociated antigens, are defined mostly by hidden amino acids, and are designated as cryptic epitopes.

Mimetic human leukocyte antigen epitopes: shown by monoclonal antibodies and extra antibodies produced on transplantation.

Background: Transplant patients often produce human leukocyte antigen (HLA) antibodies against their donors and produce more specificities than can be accounted for by HLA antigen mismatches. We theorize that the presence of extra, otherwise unexplainable specificities could be accounted for if antibodies reacted to more than one epitope (primary and mimetic) on distinct HLA molecules. The theory states that mimetic epitopes consist of the same three amino acids that comprise the primary, sterically placed approximately the same distance apart as are the corresponding amino acids of the primary.

Effect of amino acid mismatch in the UNOS 2007 dataset.

1. The study began with the 2007 UNOS dataset of 270,690 kidney transplant, from which were selected post-1995 first transplants with Caucasian donor/patients and available ABDR typing data, yielding 87,616 cases. These were split into cadaver donor (n=46,927) and living donor (n=40,689) populations.

Unexpected frequencies of HLA antibody specificities in the sera of pre-transplant kidney patients.

1. We utilize single-antigen beads to test 103 pre-transplant patients to discern HLA antibody specificity frequencies. 2.

Unexpected frequencies of HLA antibody specificities present in sera of multitransfused patients.

1. The resolution of single antigen beads is high enough to distinguish between a patient's own HLA phenotype and antibody specificity down to the allele level. 2.

HLA matching by amino acid/positions in double and triple combinations.

1. Began with the 2006 UNOS dataset and then selected for Caucasian donor/patients (post-1995 transplant and first transplant kidney only with full ABDR typing data). This was then split into cadaver donor (n = 20,542) and living donor (n = 21,890) populations.

Using the mimetic epitope concept to find a possible way to widen the graft-survival difference between matched and mismatched renal transplants.

1. Immunological responses cause antibodies to be produced, and transplant patients often produce HLA antibodies against their donors' HLA. But in many cases, more antibodies are produced than just those against mismatched HLA.

Immunogenic HLA class I epitopes identified by humoral response to pregnancies.

The main objective of this study was to understand the humoral immunity against HLA so that this knowledge can be applied clinically. We investigated the various factors resulting in antibody production by 128 mothers against the child's inherited paternal alleles. Among 128 mother-child pairs, 39 different mismatch antigens were observed.

Epitopes of HLA antibodies found in sera of normal healthy males and cord blood.

This chapter defines epitopes targeted by antibodies in the sera of two populations of healthy normal males and in cord blood samples from a third population. These epitopes are accessible for antibody binding on either the intact or dissociated forms of recombinant HLA class I single antigens. Sixty percent of these epitopes are defined by hidden amino acids, and are therefore designated as cryptic epitopes.