Repository for Antibody Incompatible Transplantation Evidence

Stability of Anti-HLA Sensitization Profiles in Highly Sensitized Kidney Transplantation Candidates: Toward a Rational Serological Testing Strategy.

Transplantation. 2022 Apr 1;106(4):869-878 doi: 10.1097/TP.0000000000003822.
Abstract
BACKGROUND:

Highly sensitized (HS) anti-HLA patients awaiting kidney transplantation benefit from specific allocation programs. Serological monitoring at 3-mo intervals is recommended to prevent unexpected positive crossmatch (XM), but this strategy is not evidence-based. Therefore, we assessed its relevance when using single-antigen flow bead (SAFB) and screening flow bead (SFB) assays.

METHODS:

We included 166 HS patients awaiting a transplant and assessed their SAFB profile during the year preceding their inclusion. Anti-HLA antibodies were evaluated by SAFB assay and compared within patients as serum pairs at 3, 6, and 9 mo. We assessed the performance of SFB for detecting changes in SAFB profiles with 35 serum pairs.

RESULTS:

On comparing 354, 218, and 107 serum pairs at 3, 6, and 9 mo, respectively, only 0.6%, 0.7%, and 1% of all antigens tested exceeded for the first time the unacceptable antigen threshold (mean fluorescence intensity ≥2000) in the most recent sample. Irrespective of the follow-up period, the calculated panel-reactive antibodies increased by a mean of 1%, and there was no significant increase in the proportion of donors at risk for positivity of flow- or complement-dependent cytotoxicity XM. The SFB did not accurately detect the variations of SAFB profiles.

CONCLUSIONS:

Changes in HS patient profiles are anecdotal and show little association with transplant access or risk for positive XM. Less-frequent monitoring in HS patients should be considered to improve cost-effectiveness without affecting transplant safety.

Metadata
LEVEL OF EVIDENCE: Case Series / Case Control / Cohort
LANGUAGE: English
ORGAN TYPE: Kidney
MESH HEADINGS: HLA Antigens; Histocompatibility Testing; Humans; Isoantibodies; Kidney Transplantation*; Kidney Transplantation / adverse effects; Serologic Tests; Tissue Donors