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Evaluation of three different laboratory methods to detect preformed human leukocyte antigen antibodies in a South African kidney transplant population
Abstract
Background: Anti-human leukocyte antigen antibodies (anti-HLA) play a crucial role in graft. Detection of anti-HLA, both pre- and post-transplant is a crucial investigation in clinical organ transplantation.
Objectives: Three methodologies for the detection of lymphocytotoxic antibodies were compared to establish which of these is best suited to optimise pre-transplant donor-recipient matching.
Methods: Serum samples from 15 renal transplant patients were tested for the presence of anti-HLA by i) cytotoxic-de- pendent cross-match (CDCXM), ii) flow cytometric cross-match (FCXM) and iii) Luminex-based donor specific antibody cross-match (DSAXM) method, Confirmatory tests for the presence of preformed HLA antibodies were tested using Lu- minex methodology.
Results: Two (13%) of the 15 patients had positive HLA Class I antibodies (Ab) using all 3 methods. An additional 2 HLA Class I Ab were identified with FCXM/CDCXM. DSAXM identified 1 HLA Class I positive, not indicated by CDCXM/ FCXM. High HLA Class II positivity (40%), identified by CDCXM, while DSAXM and FCXM identified two and one patients, respectively. CDCXM produced 4 false-positive results confirmed by lymphocyte single antigen (LSA) assay.
Conclusions: The DSAXM method appears to add value in pre-transplantation screening to identify pre-sensitised patients that may not reject the donor graft due to the absence of donor-specific antibodies.
Keywords: Preformed human leukocyte; antigen antibodies; kidney transplant; population; South Africa.