Prognosis of HTLV-I-positive renal transplant recipients.

HTLV-I is the pathogen that causes adult T-cell leukemia (ATL) and HTLV-I-associated myelopathy (HAM). The rate of disease development is low and the latency time is a few decades. However, the possible influence of immunosuppression on this disease development is unclear. The purpose of this study was to investigate the risk of development of ATL and HAM among the large number of HTLV-I-positive renal transplant recipients in western Japan. In principle immunosuppressive drugs have the possibilities to accelerate ATL development but are thought to suppress HAM development. Of 120 renal transplant recipients, 10 HTLV-I-positive recipients were reviewed, none of whom developed ATL or HAM. There are 11,896 dialysis patients in Japan and 300 dialysis patients in Okinawa who are registered with the JOTN for cadaveric renal transplant. The numbers of HTLV-I-positive patients in these groups were 97 (0.82%) and 26 (8.67%), respectively. These numbers are thought to be sufficient for an HTLV-I-positive recipient pool for HTLV-I-positive donors. Ten cases of ATL development and two of HAM development have been previously reported. Because of low number of ATL development, renal transplantation does not appear to be a contraindication for HTLV-I-positive chronic renal failure patients. In other words, kidneys from HTLV-I carriers, which include cadaveric donors, could be used for HTLV-I-positive recipients.