Superiority of Single-Antigen Bead Study in Donor-Specific Antibodies: Determination in Highly Sensitized Patients.

OBJECTIVES: The presence of donor-specific antibodies against HLA before kidney transplant has been variably associated with decreased long-term graft survival. Data on the association between pretransplant donor-specific antibodies and rejection and cause of graft failure in recipients of donor kidneys are scarce. MATERIALS AND METHODS: For this study of HLA antibody levels, we analyzed serum samples from 76 patients (48 women and 28 men) who were prepared for kidney transplant at the Baskent University Istanbul Hospital between 2017 and 2022. Levels were determined by using Lifecodes panel reactive antibody class I and II identification kits and Lifecodes LSA class I and II identification kits by the Luminex assay method. RESULTS: Multiple antigen tests showed more than 70% sensitization detected against both class I and class II antigens in our patient group. When some samples were reevaluated with the single-antigen bead method, desensitization values were shown to be considerably reduced compared with values from multiple antigen methods. CONCLUSIONS: The single-antigen-coated bead method can be useful in determining the risk of donor-specific antibodies in highly sensitized patients.

Analysis of Panel Reactive Antibodies in Renal Transplant Recipients Detected by Luminex: A Single-Center Experience.

OBJECTIVES: The role of panel reactive antibody has gained universal acceptance in solid-organ transplant. This parameter is used to gauge the level of sensitization of prospective solid-organ recipients. More than one-third of patients on wait lists for kidney transplant are sensitized. Most have previously formed donor-specific and non-donor-specific serum antibodies and/or positive crossmatch by complement-dependent cytotoxicity and/or flow cytometry. We present the rate of positivity at our institution for human leukocyte antigen antibodies and describe the condensation of antibodies in human leukocyte antigens for renal pretransplant recipients. MATERIALS AND METHODS: Between January 2011 and December 2012, six hundred twenty consecutive renal transplant recipients on the wait list at the Baskent University were evaluated for this retrospective study. Panel reactive antibody screening and definition tests were studied with Luminex assays for the combination of class I (A, B, C) and class II antigens (DR, DQ). RESULTS: We found a panel reactive antibody screening positivity in 20.4% of our patients on renal transplant waiting list. Panel reactive antibody defining tests were meaningful in 12.2% of the whole list. We observed that only panel reactive antibody class I positivity was seen in 2.2%, only panel reactive antibody class II positivity was seen in 2.7%, and both panel reactive antibody class I and class II positivities were seen in 7.2% of the defining tests. CONCLUSIONS: The estimated risk of sensitization for patients with a living donor is determined from the combined results of the crossmatch with the donor and those of the recipient's panel reactive and donor-specific antibodies. Compared with complement-dependent cytotoxicity crossmatch, Luminex assays provide greater sensitivity and specificity in detection of donor-specific antibodies.