HTLV-1 seroprevalance in sarcoidosis. A clinical and laboratory study in northeast of Iran.

Aim: Sarcoidosis is an autoimmune multiorgan granulomatosis disease with unknown origin. Some environmental factors such as viruses may induce the disease in genetically susceptible individuals. Human T cell lymphotropic virus type 1 (HTLV-1) can dysregulate the human immune system and the role of this virus in the pathogenesis of autoimmune diseases has been investigated and documented, such as in uveitis. In this study, we have focused on the seroprevalence of HTLV-1 in sarcoidosis in comparison to the normal population in the northeast of Iran, an endemic area for HTLV-1.

Methods: This cross-sectional study enrolled 125 patients with established sarcoidosis to evaluate the frequency of HTLV-1 and compare it with the normal population of Mashhad, Iran. Participants' blood samples were analyzed for HTLV-1 antibody by an enzyme-linked immunosorbent assay kit. Positive results were confirmed by polymerase chain reaction method. Finally, data were analyzed using SPSS 11.

Results: Among sarcoidosis patients 106 (84.8%) patients had a history of acute course and 19 (15.2%) had chronic sarcoidosis. Four percent of the patients versus 2.12% of the Mashhad population were HTLV-1 positive with no statistical difference (P = 0.201). In age- and sex-matched selected controls, 3.6% were HTLV-1 positive again with no statistical difference by sarcoidosis group (P = 0.52). There was no statistical difference between arthritis, erythema nodusom, uveitis, constitutional symptoms, abnormal chest radiography (parahilar lymphadenopathy) and computed tomography scan findings, respiratory symptoms, sex, the course of the sarcoidosis in HTLV-1 positive and negative sarcoidosis patients.

Conclusion: The frequency of HTLV-1 in 125 sarcoidosis patients was 4%. In comparison with prevalence of HTLV-1 in Mashhad, HTLV-1 seroprevalence did not show any significant difference.