The Role of B lymphocyte Stimulator (BlyS) In Rheumatoid Arthritis

Abstract

Rheumatoid arthritis (RA) is a common chronicinflammatory autoimmune disease of unknown etiologyaffecting approximately 1% of the world population.The synovium of the small joints of hands and feet is the first structureaffected. The subsequent inflammatory changes lead to cartilageand bone destruction.

B cell plays a critical role in RA pathogenesis in the form of production of autoantibodies like RF and Anti CCP, B cells are very efficient antigen presenting cells, B cells produce cytokines that promote formation of ectopic lymphoid structures within the joint. BAFF has emerged as a crucial factor that modulates B cell survival, activation, maturation, tolerance and homeostasis.

This study was designed to assess the role of BAFF in RA and correlation with activity and severity of the disease. The study also compared the level of BAFF between seronegative and seropositive RA patients.

In the present study 40 patients with RA who fulfilled the ACR/EULAR 2010 classification criteria were recruited and 20osteoarthritis patients were included as controls.The selected RApatients were classified into 20 seropositive RA patients and 20 seronegative RA patients.

All included patients were subjected to detailed medical history taking, with special emphasis on RA activity symptoms,RA duration in years,and extra-articular manifestations.General and local musculoskeletal examination were performed for all patients as well as laboratory investigations including (complete blood count, ESR, CRP, RF, Anti CCPand BAFF serum level), X-ray hands. This was followed by assessment of disease activity using DAS28.

In this study the age of our patients ranged from 20 to 61 with mean age 44.Female patients represented 35/40 (87.5%) of our patients and males were5/40 (12.5%).

This study showed that BAFF has role in RA as we found that serum levels of BAFF in the RA patients group were higher than the control group and female patients were having higher BAFF levels than males

Also BAFF levels in seronegative RA group were significantly higher than the seropositive group This study showed positive correlation between BAFF serum level and disease activity score DAS 28 (P value0.004) while there was no correlation between BAFF and disease severity (Larsen score), RF or Anti CCP. There was also significant positive correlation between BAFF and WBC and negative correlation between BAFF and HGB.

There was no significant correlation between BAFF level and ESR (p value 0.070) or CRP (P value 0.254).There also was no correlation with EAM, age, disease duration, and morning stiffness.