Abstract Background: Renal transplant recipients are susceptible to viral infections because of their immunocompromised background. HTLV-1 is a retrovirus that leads to adult T-cell leukemia/lymphoma or myelopathies. This study aimed to evaluate HTLV-1 antibodies among renal transplant recipients in Urmia, Iran. Materials and Methods: Serum samples of 91 renal transplant recipients from Urmia, Iran, were examined serologically for antibodies against HTLV type 1 using an enzyme-linked immunosorbent assay. Results: Mean age was 37.26 ± 14.22 years old. Only 1 patient had a positive anti-HTLV-1 enzyme-linked immunosorbent assay test, which was confirmed by Western blot. The HTLV-1–positive case did not have HTLV-associated clinical manifestation. This patient was a 45-year-old man, with no history of blood transfusion, but he did have a history of hemodialysis before transplant. Conclusions: The frequency of HTLV-1 among renal transplant recipients of our region in the northwest of Iran was not so high, and it is similar to the HTLV- 1 seroprevalence among hemodialysis patients. Still, it is more frequent among healthy blood donors as representative of the general population in our region. Key words: Human T lymphocyte virus type 1, Renal transplant, ELISA Introduction Human T-cell lymphotropic virus 1 (HTLV-1) is a retrovirus, which causes adult T-cell leukemia- lymphoma, and HTLV-associated neuropathies (1). The Middle East is mentioned as 1 of endemic regions for HTLV-1 in the world (2), but HTLV infection has a different situation through Iran. On 1 hand, Great Khorasan in northeast Iran is reported as being an endemic region for HTLV, with a prevalence of 1.97 (3, 4); on the other hand, this prevalence in general population of Urmia in northwest Iran is estimated to be 0.34% (5). Previous studies have reported higher seroprevalence among hemodialysis patients as 1 of high-risk groups (5-7). Renal transplant recipients are at a high risk of HTLV infection, not only for their compromised immune system (due to the background renal dysfunction [or probable history of blood transfusion]), but because of receiving immunosuppressive treatment to prevent graft rejection. There are few studies available regarding the HTLV-1 seroprevalence among transplant recipients, and most of them are limited to case review of their evolution (8-10). Nakamura and associates reported the seroprevalence of HTLV as 8.3% to 9.9% in their studies (11, 12). There are no data reporting this population from our country. This study is aimed to evaluate the seroprevalence of HTLV-1 among Iranian renal transplant recipients. Materials and Methods Ninety-one renal transplant recipients from the Imam-Khomeini Hospital of Urmia followed-up regularly in the transplant clinic were included randomly in our cross-sectional descriptive study. Before the study, the protocol was approved by our Seroprevalence of HTLV-1Among Kidney Graft Recipients: A Single-Center Study Zakieh Rostamzadeh Khameneh, 1 Nariman Sepehrvand, 2 Sima Masudi, 3 Ali Taghizade-Afshari 4 Copyright © Başkent University 2010 Printed in Turkey. All Rights Reserved. From the Departments of 1 Microbiology and Immunology, 2 Students’ Research Committee, 3 Epidemiology, and 4 Nephrology and Transplantation at the Umria University of Medical Sciences, Urmia, Iran. Address reprint requests to: Nariman Sepehrvand, MD, Students' Research Committee, Urmia University of Medical Sciences, Resalat Avenue, Djahad Square, Urmia, West-Azerbaijan 098-441, Iran Phone: +2937296 Fax: : +2231930 E-mail: nariman256@gmail.com Experimental and Clinical Transplantation (2010) 2: 146-149 ARTICLE