Background The TNF superfamily member B lymphocyte stimulator (BLyS), referred to as BAFF, is known to be an effective modulator of peripheral B cell homeostasis that promotes B cell survival and differentiation. BLyS is expressed by a few stromal cells, T cells, and most myeloid cell. BLyS transgenic mice show an expansion of the peripheral mature B cell compartment, hyperglobulinemia, anti-single-stranded DNA and anti-double-stranded DNA antibodies, and circulating immune complexes. A proliferation-inducing ligand (APRIL) is a homolog to BLyS that is expressed by monocytes, macrophages, DCs, T cells, and others. APRIL is virtually undetectable in normal tissues but is strongly expressed in adenocarcinomas and can accelerate the growth of malignant cells in vitro and in vivo. APRIL/BLyS heterotrimers are present in the serum of patients with systemic autoimmune diseases like rheumatoid arthritis (RA), SLE, and SS. APRIL over expression promotes a strong survival signal for both CD4+ and CD8+ T cells in vivo. T cell dependent humoral responses revealed an increase in serum IgM, while serum IgG levels remained unaffected. T cell independent type II humoral responses were also enhanced, manifested by elevated IgM and IgG serum levels. These two related members of the tumor necrosis factor family, BAFF and APRIL, are already known for their crucial role in normal B-cell survival, differentiation and apoptosis.
Objectives is to investigate the relation between levels of BAFF and APRIL in serum of patients with RA and their correlation to clinical disease and some laboratory parameters
Methods 60 patients divided into 2 groups. Group 1, 40 patients having RA and fulfilling the (ACR) criteria for diagnosis of the disease. Group 2, 20 healthy age and sex matched individuals as controls for the serum level of BAFF and APRIL. Patients positive for hepatitis C and/or B virus infection were excluded. Patients were subjected to clinical assessment of disease activity by DAS 28 score. Health assessment questionnaire for disability index (HAQ-DI) and x- ray of both hands and feet.
Routine laboratory investigations, rheumtoid factor titre by Rose Waaler technique, Anti- cyclic citrullinated peptide Abs titre. Detection of serum and synovial fluid levels of BAFFand APRIL by ELISA
Conclusions the elevation of BAFF and APRIL in RA patients supports that B cell activation has a role in the pathogenesis of rheumatoid arthritis. BAFF and APRIL correlates with inflammatory, autoantibody markers and activity markers which confirm that targeting these cells might be a useful strategy in treatment of rheumatoid arthritis.
Disclosure of Interest None Declared