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

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.