Is there any Association Between Human Lymphotropic Virus Type I (HTLV-I) Infection and Systemic Lupus Erythematosus? An Original Research and Literature Review

Objective(s): Systemic lupus erythematosus (SLE) is an autoimmune disease with unknown etiology. Some environmental factors can induce SLE in genetically susceptible individuals; for example, sun exposure and some viral infections may emerge the disease manifestations. Human T lymphotropic virus type 1 (HTLV-I) can dysregulate the human immune system, and the role of this virus in the pathogenesis of autoimmune diseases is under investigation. There are conflicting data about the role of HTLV-I in the pathogenesis of several autoimmune diseases such as SLE. In this study, we have focused on the correlation between HTLV-I infection and SLE in the northeast of Iran, an endemic area for the virus. Materials and Methods: One hundred and thirty women with SLE and 915 healthy controls were screened for HTLV-I by enzyme linked immunosorbent assay (ELISA). Western blot method was used for confirmation of the positive results done by ELISA in the patients and the control group. Results: Two (1.5%) of the patients and 23 (2.5%) of the healthy controls were HTLV-I seropositive. There was not a statistical difference between patients and controls in the number of HTLV-I seropositive samples (P=0.49). Conclusion: This cross-sectional case-control study did not find any association between HTLV-I and SLE. With regard to the previous studies, these controversies may stem from differences in ethnic background. Geographical and environmental factors should also be taken into account.