Background Human parvovirus B19 (B19) and herpesviruses-6 (HHV-6) and -7 (HHV-7) are immunomodulating viruses and could be the possible causes of the initial immune response or the immune process what promote the development of rheumatoid arthritis (RA) in predisposed humans. Persistent infection of such pathogens like persistent herpesviruses and B19 may influence the clinical course of RA – disease activity and aggressivity.
Objectives The aim of this study was to assess whether B19, HHV-6 and HHV-7 infection makes course of RA more active and more aggressive.
Methods 51 RA patients were examined for the presence of anti-B19 antibodies and B19, HHV-6 and HHV-7 virus specific DNA by recomLine Parvovirus B19 IgG and IgM test and nested PCR, respectively. Indices of RA activity (the morning stiffness, the disease activity score from examined 28 joints, the level of C-reactive protein and erythrocyte sedimentation rate) as well as aggressivity [rheumatoid factor (RF) and antibodies against cyclic citrullinated protein (anti-CCP)] were analysed depending on the presence of B19 and HHV-6 and HHV-7 infection markers.
Results Active B19 infection (presence of virus specific IgM class antibodies or viremia) was detected in 35.3% RA patients, but 39.2% patients had only virus specific IgG class antibodies and in 11.8% the presence of virus specific sequences was detected in DNA isolated from whole blood and cell-free blood plasma 13.7% RA patients were without B19 infection markers. In patients with active B19 infection the indices of disease activity were significantly higher (DAS28 – p=0.027 and CRO – p=0.034) comparing to the patients with virus specific IgG class antibodies only. Moreover, in patients with virus specific IgM class antibodies the higher mean indices of disease aggressivity were determined. In our cohort 7.8% RA patients had persistent HHV-6 and 27.5% persistent HHV-7 infection, but 58.4% patients had persistent HHV-6 and HHV-7 co-infection. In 15.7% patients' active phase of HHV-6 and in 21.6% active phase of HHV-7 persistent infection was detected, but 3.9% patients had active HHV-6 and HHV-7 co-infection. The higher disease activity indices were detected in patients with active HHV-7 infection (CRO – p=0.039) and in patients with active HHV-6 and HHV-7 co-infection (DAS28 – p=0.037 and CRO – p=0.045) comparing to the patients with latent/persistent human beta-herpesviruses' infection. Disease aggressivity factor anti-CCP was significantly higher (p=0.015) in patients with active than in patients with latent/persistent HHV-6 infection. In most patients with active B19, HHV-6 and HHV-7 infection, disease aggressivity indices RF and anti-CCP were increased comparing with patients with latent/persistent infection, but there were no significant differences between the groups.
Conclusions Active B19, HHV-6 and HHV-7 infection mostly increases RA activity, but also have an effect on disease aggressivity.
Disclosure of Interest None declared