High prevalence of antibodies against HERV-K10 in patients with testicularcancer but not with AIDS

Human endogenous retrovirus K10 (HERV-K10) env and gag expression has been detected in placenta. embryonic tissue, and cell lines. By transfection, th ese sequences have been expressed in insect cells and developed into serolo gical assays, revealing HERV-K10 antibodies in patients with testicular can cer. Patients with BIDS are at an increased risk for testicular cancer and frequently reactivate latent infections. We postulated that HERV-K10 seropr evalence might be increased with HIV infection or AIDS. Stored, frozen serum samples from 52 patients with testicular cancer (8 pat ients with HIV and 30 patients with samples near the time of diagnosis) and 84 controls (40 patients with HIV) were diluted 1:40 and tested by immunof luorescence against SF158 cells transfected with HERV-K10 env [ENV1.9(+)] o r gag (pACGAG), Seroprevalence rates were compared cross-sectionally in cases and controls, excluding those with indeterminate results (3 of 30 cases and 7 of 84 cont rols), and also were examined longitudinally in the cases before or after d iagnosis of testicular cancer. Seroprevalence to HERV-K10 Env or Gag was 17 of 27 testicular cancer patien ts (63%) around the time of diagnosis, compared to 4 of 77 controls (5%; P < 0.0001). Seroprevalence was similar (50% to 60%) with seminoma, teratocar cinoma, or embryonal carcinoma, and it was not increased with HIV infection in either cases (33%) or controls (3%). HERV-K10 antibodies were detected in 12 of 19 cases (63%) more than 6 months before seminoma diagnosis, as we ll as in four cases with residual or recurrent malignancy more than 1 month after initial diagnosis. Thus, HERV-K10 antibodies are detected frequently with testicular cancer an d seem to resolve rapidly with effective therapy of the malignancy, Antibod y reactivity also occurs in similar to 5% of controls, perhaps because of n onspecific or cross-reactive epitopes, HIV and AIDS were not associated wit h HERV-K10 antibodies, thus, leaving their higher risk of testicular cancer unexplained.