Evaluation of pretransplant immunologic status in kidney-transplant recipients by panel reactive antibody and soluble CD30 determinations

Abstract

Objectives: To retrospectively compare the accuracy of pretransplant panel of reactivity antibodies (PRA) and serum level of soluble CD30 (sCD30) in predicting early (<6 months) acute rejection (AR) in living-donor and deceased-donor kidney-transplant (KT) patients.

Methods: Pretransplant sera of 24 KT recipients were retrospectively tested for sCD30 and compared with PRA. Inclusion criteria were de novo graft patients on calcineurin-inhibitor-based immunosuppression, minimum follow-up of 1 year, alive with a functioning graft, and stable renal function over the last 12 months. Objective measures were incidence of biopsy-proven AR (BPAR) within 6 months of KT and sCD30 and PRA diagnostic indexes. The relative risk (RR) of BPAR for each test was also obtained.

Results: Fourteen (58.3%) patients presented at least one episode of BPAR within 6 months of KT. All rejection episodes were responsive to steroid treatment. PRA was positive in six (25%) patients, and four (66.7%) of them presented at least one episode of BPAR. sCD30 tested positive in nine (37.5%) patients, and all these later presented at least one episode of BPAR. sCD30 and PRA diagnostic indexes in predicting early (< 6months) BPAR were sensitivity 64.2% versus 28.5%; specificity 100% versus 80%; accuracy 79.1% versus 50%; positive predictive value 100% versus 66.6%; and negative predictive value 66.6% versus 44.4%. The RR of early AR was 1.4 in PRA-positive patients and extremely higher in the sCD30-positive group.

Conclusions: Pretransplant sCD30 is a more accurate predictor of AR when compared with PRA. These results support its use in the pretransplant work-up of kidney-graft recipients.