Serological and virological evidence of human T-lymphotropic virus in systemic lupus erythematosus.

We present evidence that systemic lupus erythematosus (SLE) patients, but not other mixed connective tissue disease patients, have been exposed to a retrovirus similar or identical to known human T-lymphotropic viruses (HTLV). Serological studies demonstrated a high incidence of seropositivity in SLE patients to HTLV-I antigens by indirect immunofluorescence and Western blot analysis, and to HTLV-III by Western blot analysis. Furthermore, peripheral blood mononuclear cells from four patients with SLE cultivated in vitro expressed HTLV-I antigens after 3 days or more in culture, and reverse transcriptase activity was detected in supernatants from short-term cultures.