Human retroviruses including human immunodeficiency virus (HIV) and human T cell lymphotrophic virus Types I and II (HTLV-I/II) have been associated with forms of connective tissue autoimmune diseases including systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA). We looked for evidence of HTLV-I/II infection in a large population of SLE, RA, and control patients.
One hundred fifteen patients with connective tissue autoimmune disease and other rheumatological disorders were screened for antibodies to HTLV-I/II by Western immunoblots (WIB). Due to the transforming characteristic of these retroviruses, the patients' peripheral blood mononuclear cells (PBMNC) were cultured in attempts to establish continuous cell lines. Furthermore, PBMNC culture supernatants were analyzed for reverse transcriptase activity and/or HTLV-I/II gag antigen production. The presence of HTLV-I/II proviral sequences in short term culture and fresh PBMNC was determined by Southern blot analysis and polymerase chain reaction (PCR), respectively. respectively.
All 115 patients were HTLV-I/II and HIV seronegative. Seventy-four attempts to establish PBMNC cell lines from 65 patients were unsuccessful with a mean culture survival time of 3.6 (+/- 1.4) months. Reverse transcriptase activity and HTLV-I/II gag antigen production were not detected in 51 and 16 culture supernatants tested, respectively. Cells from 11 patients tested by Southern blot analysis and from 57 patients tested by PCR were negative for HTLV-I/II related sequences.
Our results failed to establish an association between human retroviruses (HTLV-I/II and HIV) and SLE, RA, or other rheumatological disorders. However, these results do not rule out other exogenous or endogenous retroviruses that may play a role in the initiation and/or promotion of these diseases.