Table 1.
Studies providing evidence on the role of retroviruses in the pathogenesis of Sjögren's syndrome
| Retrovirus | Study | Origin | Main findings |
|---|---|---|---|
| HTLV-1 | |||
| [12] | USA | SS-like illness developed in HTLV-I-infected patients with tropical spastic paraparesis. | |
| [13] | Europe | An antigen reactive with a monoclonal antibody to HTLV-I p19 was present in the LSG of patients with SS. | |
| [14] | Japan | Thirty-six percent of patients with primary SS were found, by ELISA, to be positive for serum antibodies to HTLV-I. | |
| [15] | Japan | Rates of HTLV-1 seroprevalence were 23% (17/74) among patients with SS and 3% (916/27,284) among blood donors. However, the difference between patients with systemic lupus erythematosus and blood donors was insignificant. | |
| [17] | Europe | Serum antibodies to HTLV-I were detected in 2 to 5 out of 11 patients with SS. | |
| [18] | Japan | HTLV-I-infected T cells expressing TCR with a conserved motif accumulated in both HTLV-I-associated and idiopathic SS | |
| [19] | Japan | HTLV-I proviral DNA was present in the nucleus of the infiltrating T cells but not in either the epithelial cells or the acinar cells of the salivary glands of HTLV-I-seropositive patients with SS. | |
| [20] | Japan | Definitive SS was diagnosed in 6 patients and probable SS in 2 patients among 10 patients with HAM. | |
| [21] | Japan | Definite SS was diagnosed in 13 out of 20 patients with HAM. | |
| [22] | Japan | The HTLV-I tax gene, but not the HTLV-I gag, pol, or env genes, was detected in LSG samples from 4 out of 14 patients with SS. | |
| [23] | Europe | The HTLV-I tax gene, but not the gag, pol, or env genes, was detected in LSG sections from 2 out of 9 patients with SS and from none of the control subjects. | |
| [24] | Europe | The tax gene of HTLV-I was detected in LSG from 15 out of 50 of patients (30%) with SS, 9 out of 32 patients (28%) with other inflammatory processes (3/9 graft-versus-host disease, 5/19 extravasated cysts, and 1/4 sarcoidosis), and only 1 out of 26 patients (4%) with normal LSG. | |
| [25] | Japan | The HTLV-I tax gene was detected in LSG of 3 out of 17 seronegative patients (18%) with SS. | |
| [42] | USA | An autoimmune exocrinopathy with histopathological findings similar to those of SS was observed in HTLV-1 tax transgenic mice. | |
| HIV-1 | |||
| [27] | USA | An SS-like illness was reported among HIV-1-infected patients. | |
| [28,29] | USA | The DILS was described as a disorder affecting a subgroup of patients with HIV-1 infection. | |
| [30] | Europe | The prevalence of DILS among HIV-1-infected patients was 7.79%. | |
| [31] | USA | The prevalence of DILS among HIV-1-infected patients was 32.3%. | |
| [32] | USA-Africa | The prevalence of DILS in patients from the US was 6%. The prevalence in patients with HIV infection from Cameroon was 48%. | |
| [33] | Europe | The prevalence of HIV-1-related SS dropped from 8% in the pre-HAART era to 1.5% in the post-HAART era. | |
| [34] | USA | The prevalence of DILS dropped significantly in the post-HAART era. | |
| HIAP-I | |||
| [37] | USA | HIAP-I has been identified in lymphoblastoid cells cocultured with homogenates of salivary glands from patients with SS. | |
| HRV-5 | |||
| [40] | Europe | Novel sequences spanning parts of the protease and reverse transcriptase open reading frames of a retrovirus were detected in LSG tissues of eight patients with SS. | |
| [41] | Europe | Two out of 55 LSG samples from patients with SS were positive for HRV-5 proviral DNA. |
DILS, diffuse infiltrative lymphocytosis syndrome; ELISA, enzyme linked immunosorbent assay; HAART, highly active anti-retroviral treatment; HAM, HTLV-I (human T lymphotropic virus type 1)-associated myelopathy; HIAP-I, human intracisternal A-type retroviral particle; HIV-1, human immunodeficiency virus-1; HRV-5, human retrovirus-5; HTLV-1, human T lymphotropic virus type 1; LSG, labial salivary gland; SS, Sjögren's syndrome; TCR, T-cell receptor.