['We sought to investigate the relationship between serum level of sCD30 and recipient/graft survival rates, rejection types, as well as other prognostic factors among Chinese kidney transplant patients.', 'We performed enzyme-linked immunosorbent assays of serum sCD30 levels in duplicate among retrospective cohort of 707 renal transplant patients.', 'The incidences of rejection increased in relation to the pretransplant sCD30 level. The reversal rates of rejection were 100%, 90.6%, and 78.6% for the low, intermediate, and high sCD30 groups. This observation suggested that high levels of sCD30 and pretransplant panel-reactive antibody (PRA)-positive patients are risk factors for acute rejection with odds ratios of 6.862 and 1.756. High sCD30 was an independent risk factor for functional graft survival. The 5-year graft survival rates were 99.39% +/- 6.1%, 93.11% +/- 1.93%, and 82.07% +/- 3.97% among the low, intermediate, and high sCD30 groups, while the 5-year recipient survival rates were 89.25% +/- 2.41%, 91.82% +/- 1.64%, and 88.85% +/- 2.36%, respectively. Increased sCD30 levels were observed among patients who were PRA-positive, cytomegalovirus antigens or antibodies positive, on long-term dialysis, and <or= 20 years old.'] Does high serum level of the soluble CD30 identify Chinese kidney transplant recipients at high risk of unfavorable outcome?