The primary Sjögren's syndrome (SS) is a systemic disease which destroys the exocrine glands by autoimmune mechanisms. The etiology of this syndrome is unknown although different virus are involved in its genesis.
The presence of serologic reactivity IgG and IgM versus the human immunodeficiency virus (HIV-1), HIV-2, HTLV-I and HTLV-II were studied in 14 patients with SS and in 15 controls. Likewise, the presence of retroviral genomic sequences was analyzed in 7 of these patients by polymerase chain reaction (PCR).
All the patients with SS were negative by enzymoimmunoassay (EIA) versus known retrovirus. However, more than 70% presented reactivity versus different nuclear proteins, particularly versus p24 of HTLV-I in Western blot (WB). These results were negative in the control group. Genomic analysis by PCR did not confirm the presence of specific sequences in any of the known human retroviruses in the patients with SS, nonetheless, in 3 of the 7 samples analyzed by PCR, related retroviral sequences were detected.
The presence of serologic reactivity in Western blot versus some viral proteins and the similarity of genomic sequences in some cases suggests that a retrovirus related with those which are currently known, particularly with the HTLV-I, may be involved in the genesis of Sjögren's syndrome.