Parvovirus B19 infection modulates the levels of cytokines in the plasma of rheumatoid arthritis patients.

Background: Parvovirus B19 (B19V) infection is associated with various autoimmune diseases. We investigated the levels of pro-inflammatory (IFNᵧ, TNFα, IL-2, IL-12) and anti-inflammatory (IL-4, IL-10) cytokines in the plasma of B19V DNA positive (B19) and negative (B19) rheumatoid arthritis (RA) patients in comparison with the control group (healthy persons).

Methods: Blood samples were collected from 118 patients with RA and 49 healthy voluntaries. B19V sequence was determined in whole blood and cell-free plasma DNA by nested PCR. The levels of cytokines in the plasma and cell culture medium from Concanavalin A (ConA) or B19V VP1 protein stimulated PBMC were determined by ELISA.

Results: The levels of IL-4, IL-10, IL-12, IL-2 and TNFα were higher in plasma of RA patients in comparison with control persons. B19 controls and RA patients had lower levels of IFNᵧ in comparison with B19 controls and RA patients. Within RA patients the plasma levels of IFNᵧ were lower in patients with low RA disease activity or remission. Plasma level of IL-4 was increased and IL-10 level was decreased in B19 RA patients in comparison with B19 RA patients and did not differ between B19 and B19 controls. B19V infection did not affect plasma levels of IL-12, IL-2, and TNFα. ConA and B19 VP1 protein stimulated PBMC from RA patients produced less IFNᵧ than stimulated PBMC from the healthy controls.

Conclusions: B19V infection could differently modulate the amount of cytokines in the plasma of healthy persons and RA patients. Decreased production of IFNᵧ and raised level of plasma IL-4 in RA patients could lower antiviral clearance.