Low levels of human leukocyte antigen donor-specific antibodies detected by solid phase assay before transplantation are frequently clinically irrelevant

Hum Immunol. 2009 Aug;70(8):580-3. doi: 10.1016/j.humimm.2009.04.011. Epub 2009 Apr 16.

Abstract

Since new technologies based on solid phase assays (SPA) have been routinely incorporated in the transplant immunology laboratory, the presence of pretransplantation donor-specific antibodies (DSA) against human leukocyte antigen (HLA) molecules has generally been considered as a risk factor for acute rejection (AR) and, in particular, for acute humoral rejection (AHR). We retrospectively studied 113 kidney transplant recipients who had negative prospective T-cell and B-cell complement-dependent cytotoxicity (CDC) crossmatches at the time of transplant. Pretransplantation sera were screened for the presence of circulating anti-HLA antibody and DSA by using highly sensitive and HLA-specific Luminex assay, and the results were correlated with AR and AHR posttransplantation. We found that approximately half of our patient population (55/113, 48.7%) had circulating anti-HLA antibody pretransplantation. Of 113 patients, 11 (9.7%) had HLA-DSA. Of 11 rejection episodes post-transplant, only two patients had pretransplantation DSA, of whom one had a severe AHR (C4d positive). One-year allograft survival was similar between the pretransplantation DSA-positive and -negative groups. Number, class, and intensity of pretransplantation DSA, as well as presensitizing events, could not predict AR. We conclude that, based on the presence of pretransplantation DSA, post-transplantation acute rejections episodes could not have been predicted. The only AHR episode occurred in a recipient with pretransplantation DSA. More work should be performed to better delineate the precise clinical significance of detecting low titers of DSA before transplantation.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Antibody Formation
  • Child
  • Child, Preschool
  • Female
  • Graft Rejection / blood
  • Graft Rejection / diagnosis*
  • Graft Rejection / immunology*
  • Graft Rejection / prevention & control
  • HLA Antigens / immunology*
  • Humans
  • Immunosorbent Techniques
  • Isoantibodies / blood
  • Isoantibodies / immunology*
  • Kidney Transplantation*
  • Male
  • Microspheres
  • Middle Aged
  • Predictive Value of Tests
  • Prognosis
  • Retrospective Studies
  • Risk Factors
  • Transplantation Immunology*

Substances

  • HLA Antigens
  • Isoantibodies