Abstract
AIM: To investigate T-cell subpopulations in peripheral blood of human parvovirus B19 DNA-positive (B19(+)) and -negative (B19(-)) patients with rheumatoid arthritis (RA) and healthy persons. PATIENTS AND METHODS: Blood samples were collected from 115 patients with RA and 47 healthy volunteers; 27 patients with RA and nine controls were B19(+) Cluster of differentiation (CD) 4, 8, 25 and 45RA were analyzed on blood cells. CD25 expression on CD4(+)CD45RA(+), CD4(+)CD45RA(-), CD8(+)CD45RA(+), CD8(+)CD45RA(-) subsets were analyzed by flow cytometry. RESULTS: The percentage of CD25(low) and CD25(hi) cells was increased on CD4(+)CD45RA(+), CD4(+)CD45RA(-) T-cells and the percentage of CD25(+) cells was increased on CD8(+)CD45RA(+), CD8(+)CD45RA(-) T-cells of B19(+) patients with RA in comparison with B19(-) patients and controls. CONCLUSION: Raised levels of CD4 and CD8 regulatory T-cells in B19(+) RA patients could cause down-regulation of antiviral clearance mechanisms and lead to activation of persistent human parvovirus B19 infection in patients with RA.