Table 3: Summary of Studies Implicating HERVs in Autoimmune Rheumatic Disease and Molecular Techniques Used in Each

Disease HERV Study Molecular Technique Significance/Result
RA HTLV-1 p19 and HIV p24 antigens Ziegler et al. [35, 36] Western blot, ELISA 45-55% patients expressed HTLV-1 antigen in synovial tissue, without serological HTLV-1 infection
HERV-K10 Nelson et al. [31] Quantitative RT-PCR Significant association of sequence homology between HERVs and autoimmune rheumatic diseases
HERV-K10 Reynier et al. [13] NASBA HERV-K detected in plasma of RA patients, with higher levels observed for those with active disease.
HERV-K10 Ejtehadi et al. [46] Multiplex RT-PCR Enhanced expression of HERV-K10 in RA
Nakagawa et al. [49] RT-PCR Multiple HERVs were expressed in normal and diseased synovium
HERV-K10 Friemanis et al. [17] Quantitative RT-PCR, ELISA RA patients exhibited significantly elevated levels of HERV-K gag activity compared to controls
HERV-K113 Krzysztalowska-Wawrzyniak et al. [47] PCR Significantly increased prevalence of HERV-K113 in patients with SLE and RA
SLE HRES-1 Banki et al. [39] Western blot, ELISA Sera from patients with autoimmune disease had increased HRES-1 peptide binding activity than controls.
HRES-1 Perl et al. [63] Western blot, ELISA Autoantibodies to HRES-1 found in autoimmune disease, especially if Ro / La negative.
HRES-1 Pullman et al. [69] Southern blot, PCR The HRES-1 locus at the 1q42 chromosomal region influences SLE development and disease manifestations
HIAP-1 Deas et al. [72] Polyacrylamide gel electrophoresis (PAGE) Cells exposed to HIAP-1 may be protected from apoptosis.
HTLV-1 p19 and HIV p24 antigens Talal et al. [37-38] Western blot Antibodies to p24 gag of HIV-1 found in absence of HIV-1 infection. Anti-Sm antibodies can cross-react with p24 gag.
ERV-3 Li et al. [30] Western blot, ELISA ERV-3 may have a role in the pathogenesis of neonatal congenital heart block.
JIA HERV-K18 Sicat et al. [82] Semi-quantitative RT-PCR HERV-K18 levels elevated suggesting a mechanism for autoimmunity by superantigen stimulation of auto-reactive T cells.
SJS HIAP-1 Garry et al. [73] PCR HIAP-1 detected in cells exposed to salivary tissue from patients with Sjögren's syndrome.
HRES-1 Brookes et al. [40] Northern blot, ELISA Significantly elevated levels of antibodies to HTLV-1 were found in several diseases.
HERV-E env protein (λ4-1) Hishikawa et al. [96] Western blot Anti-p30gag antibodies detected in sera of several diseases