To evaluate the immune response and proviral load in individuals with human T-lymphotropic virus type 1 (HTLV-1) and erectile dysfunction (ED) compared with those in the controls.

We performed a cross-sectional study of 102 men aged 18-70 years with positive serology for HTLV-1, who were interviewed from 2004 to 2010. The study sample was divided into 2 groups: group 1, 42 HTLV-1–infected men with ED, as determined by the International Index of Erectile Function-5 score; and group 2, 60 HTLV-1–infected men without ED. The cytokines interferon-γ and tumor necrosis factor-⍺, and the proviral load were analyzed between the 2 groups.

Compared with those without ED, the men with ED had greater levels of tumor necrosis factor-⍺ (545.37 ± 877.06 vs 509.39 ± 724.70 pg/mL) and interferon-γ (1154.35 ± 1282.98 vs 1122.78 ± 1573.16 pg/mL), but this difference was not significant (P = .69 and P = .57, respectively). The proviral load was 135,695 ± 190,113 copies/10⁵ cells in the ED group and 47,607 ± 83,129 copies/10⁵ cells in the non-ED patients, with a statistically significant difference (P = .02). When ED was stratified as mild, moderate, and severe, no difference was found in the proviral load among the ED groups (P = .09); however, the levels were greater in the severe forms.

The association of a greater proviral load in men with ED with HTLV-1 gives support to the idea that ED is part of the autonomic syndrome related to viral infection and should be investigated for early identification of the syndrome.