Polymerase chain reaction fails to incriminate exogenous retroviruses HTLV-I and HIV-1 in rheumatological diseases although a minority of sera cross react with retroviral antigens.
OBJECTIVE
To investigate the presence of antibodies to HTLV and HIV retroviral antigens in the rheumatological diseases rheumatoid arthritis (RA), polymyositis/dermatomyositis (PM/DM), primary Sjögren's syndrome (pSS), and systemic lupus erythematosus (SLE), and to use polymerase chain reaction (PCR) to seek these exogenous retroviruses in proviral form in cellular DNA from these patients.


METHODS
Thirty patients with 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 immunosorbent assay (ELISA) and Western blot analysis. Seropositivity to HIV-1 was also sought. DNA was extracted from peripheral blood lymphocytes, synovial tissue and muscle biopsies and tested by polymerase chain reaction using consensus primers for HTLV-I and HIV-1.


RESULTS
In HTLV-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 normal subjects were negative. In a control group which included osteoarthritis, Crohn's disease and bacterial endocarditis patients, only two of 80 proved positive in this system. Validation of these sera by Western 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 HTLV-I and HIV-1 infection as causative agents in these rheumatological diseases although a minority of patients possess antibodies that are weakly cross-reactive with retroviral antigens.
Nelson
P N
PN
Division of Immunology, St George's Hospital Medical School, London, United Kingdom.
Lever
A M
AM
Bruckner
F E
FE
Isenberg
D A
DA
Kessaris
N
N
Hay
F C
FC
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001172:Arthritis, Rheumatoid / Q000821:virology; D001483:Base Sequence; D015153:Blotting, Western; D002648:Child; D002675:Child, Preschool; D003240:Connective Tissue Diseases / Q000821:virology*; D003429:Cross Reactions; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D015483:HIV Antibodies / Q000097:blood; D015497:HIV-1 / Q000302:isolation & purification*; D015481:HTLV-I Antibodies / Q000097:blood; D015368:Human T-lymphotropic virus 1 / Q000302:isolation & purification*; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000821:virology; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D017285:Polymyositis / Q000821:virology*; D012859:Sjogren's Syndrome / Q000821:virology
D015483:HIV Antibodies; D015481:HTLV-I Antibodies