POLYMERASE CHAIN-REACTION FAILS TO INCRIMINATE EXOGENOUS RETROVIRUSESHTLV-I AND HIV-1 IN RHEUMATOLOGICAL DISEASES ALTHOUGH A MINORITY OF SERA CROSS-REACT WITH RETROVIRAL ANTIGENS

Objectives-To investigate the presence of antibodies to HTLV and HIV r etroviral antigens in the rheumatological diseases rheumatoid arthriti s (RA), polymyositis/dermatomyositis (PM/DM), primary Sjogren's syndro me (pSS), and systemic lupus erythematosus (SLE), and to use polymeras e chain reaction (PCR) to seek these exogenous retroviruses in provira l form in cellular DNA from these patients. Methods-Thirty patients wi th active RA, 13 with PM, 14 with pSS and five with SLE were recruited and their sera tested for antibodies to HTLV-I in enzyme linked immun osorbent assay (ELISA) and Western blot analysis. Seropositivity to HI V-1 was also sought. DNA was extracted from peripheral blood lymphocyt es, synovial tissue and muscle biopsies and tested by polymerase chain reaction using consensus primers for HTLV-I and HIV-1. Results-In HTL V-I ELISA, nine rheumatological sera (4/30 RA, 3/13 PM/DM and 2/5 SLE patients) were considered positive; 14 from pSS patients and 30 from n ormal subjects were negative. In a control group which included osteoa rthritis, Crohn's disease and bacterial endocarditis patients, only tw o of 80 proved positive in this system. Validation of these sera by We stern blotting generally revealed weak reactivity against a variety of HTLV-I antigens. PCR of genomic DNA derived from patients' peripheral blood mononuclear cells did not reveal the presence of HTLV-I and HIV -1 target sequences. Conclusions-This study shows that PCR precludes H TLV-I and HIV-1 infection as causative agents in these rheumatological diseases although a minority of patients possess antibodies that are weakly crossreactive with retroviral antigens.