Rheumatoid arthritis (RA) is a common chronic inflammatory disease affecting about 1% of the
general population [1]. It is characterized by autoantibody production, synovial tissue inflammation and hyperplasia with subsequent cartilage and bone destruction [2]. Although the pathogenesis of RA remains incompletely clear, but generally it occurs as a result of an inadequate immune response in genetically predisposed individuals in response to environmental triggers. Bacteria and viruses are acknowledged as chief triggers [3, 4]. The microorganisms involved in triggering RA may include polymicrobial agents or the cumulative effect of several bacterial/viral factors [5]. Higher frequency and increased antibody titers against Epstein-Barr virus (EBV) compared to controls have been reported [6, 7]. In addition to EBV, other viruses have been involved, including
human parvovirus B19 (B19) [8, 9], and cytomegalovirus [10].
B19 is a single-stranded DNA virus, which replicates primarily in the erythroblasts in the bone marrow and it can persist lifelong in many different cell types throughout the body following acute infection [11]. B19 is transmitted via respiratory secretions, contaminated blood and blood products, organ transplantation and vertical transmission from mother to fetus [12]. Following acute infection, B19 virus persists in many different tissues, including skin, bone marrow, synovium, and liver, and it is believed that this is a lifelong phenomenon [13]. In children, B19 infection causes erythema infectiosum (fifth disease), while in adults, it can be asymptomatic or can cause various manifestations as arthralgia, arthritis, transient aplastic crisis and chronic anemia [14, 15].
Conflicting data are available regarding the etiologic associations of B19 with RA.
Some publications [16, 17], denied the association between B19 and rheumatic disease manifestations, while others [18-20] displayed its role in the susceptibility to 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 and severity.
|
