Posttransplant malignancies and their relationship with human leukocyte antigens in kidney allograft recipients.

INTRODUCTION Kidney transplant recipients are at increased risk of cancers, most frequently skin cancers, and in some regions, Kaposi sarcoma and non-Hodgkin lymphoma. We sought to investigate the associate of the most frequent malignancies among our patients with human leukocyte antigens (HLAs). MATERIALS AND METHODS We performed a retrospective study on 44 kidney allograft recipients who had posttransplant malignancy and 44 kidney allograft recipients without malignant lesions (control group). All of the patients had been treated by immunosuppressive regimens including cyclosporine plus prednisolone or cyclosporine, prednisolone, and mycophenolate mofetil. Data on HLA typing were achieved from their transplant records. RESULTS There were 15 patients (34.1%) with Kaposi sarcoma; 13 (29.6%) with non-Hodgkin lymphoma, 6 (13.6%) with skin cancer, 2 (4.5%) with ovary cyst adenocarcinoma, and 8 (18.2%) with other tumors. The mean interval from transplantation to diagnosis of malignancy was 15.3 month. Twelve patients died of cancer during the follow-up (mean, 12.3 years). No significant difference was noted in the age, sex, and time of transplantation between these patients and those in the control group. Kaposi sarcoma was associated with HLA-CW4 (P = .03) with an odds ratio of 4.96 (95% confidence interval, 2.90 to 8.12). CONCLUSIONS We found HLA-CW4 as a risk factor of Kaposi sarcoma in kidney allograft recipients. Screening for malignancies after kidney transplantation sounds very important with special attention to the specific environmental and genetic factors in each population.