Human Parvovirus B19 Infection in Rheumatoid Arthritis Patients: Screening and Clinical Significance.

Rheumatoid arthritis (RA) is a common chronic inflammatory disease, affecting about 1% of the general population. Conflicting data are available regarding the etiologic association of human parvovirus B19 (B19) infection with RA. This study aimed to determine the prevalence of B19 infection in patients with RA compared to healthy controls and to assess its possible association with disease activity or severity. The study included 40 RA patients and 40 age and sex matched apparently healthy controls. Detection of B19 DNA by nested PCR and the detection of anti-B19 IgM and IgG by ELISA) were performed for patients and controls. It was found that B19 infection is more prevalent in patients with RA than healthy controls as the frequency of detection of B19 DNA and anti-B19 IgG was significantly higher in RA patients than healthy controls (P=0.003 and P=0.04, respectively) but not IgM. It was concluded that B19 infection may have a role in the etiopathogenesis of RA but not involved in disease activity or severity.

Role of T helper 17 cells in the pathogenesis of systemic lupus erythematosus.

Systemic lupus erythematosus (SLE) is a multi-organ autoimmune disorder that occurs in genetically prone individuals. Autoimmunity could not be simply explained by Th1/Th2 cell paradigm. T helper 17(Th17) cells producing the cytokine interleukin-17 (IL-17) may explain the promotion and progression of autoimmune phenomena. This study aimed to investigate the role of Th17cells, IL-17 and interleukin-23 (IL-23) in the pathogenesis of SLE and their correlation with disease activity. The frequencies of circulating Th17 cells in 15 patients with active SLE, 15 patients with inactive disease and 15 healthy control subjects were measured using Flowcytometry after stimulation with phorbol myristate acetate (PMA) and ionomycin for 4 hours. Serum levels of IL-17 and IL-23 were measured using the enzyme linked immunosorbent assay (ELISA). Significantly higher mean frequencies of circulating Th17 cells were found in active SLE patients (1.54 +/- 0.38%, P < 0.001) and inactive SLE patients (1.23 +/- 0.25%, P = 0.009) compared to the control group (0.88 +/- 0.41%). The frequencies of circulating Th17 cells positively correlated with the SLEDAI score (r = 0.812, P < 0.001). The serum levels of IL-17 and IL-23 were significantly higher in active SLE (P < 0.001) and inactive SLE patients (P < 0.001) than the control group while, serum levels of both cytokines correlated positively with SLEDAI score (r = 0.661, P < 0.01 and r = 0.701, P < 0.01 respectively). There was significant positive correlation between the frequency of circulating Th17 cells and plasma levels of IL-17 and IL-23 (r = 0.789, P < 0.001) and (r = 0.792, P < 0.001) respectively. Results of this study provides evidence of a role of Th17 cells in the pathogenesis of SLE, and offer scientific rationale for the utility of Th17 cells, IL-17 and IL-23 as biological markers for SLE disease activity. This would raise the possibility of anti-IL-17 and anti-IL-23 as innovative therapeutic options in controlling disease activity of SLE.