TY - JOUR T1 - BAFF Expression Correlates with Idiopathic Inflammatory Myopathy Disease Activity Measures and Autoantibodies JF - The Journal of Rheumatology JO - J Rheumatol SP - 294 LP - 302 DO - 10.3899/jrheum.120555 VL - 40 IS - 3 AU - CONSUELO M. LÓPEZ De PADILLA AU - KELLY T. McNALLAN AU - CYNTHIA S. CROWSON AU - HATICE BILGIC AU - RICHARD J. BRAM AU - MOLLY S. HEIN AU - STEVEN R. YTTERBERG AU - SHREYASEE AMIN AU - ERIK J. PETERSON AU - EMILY C. BAECHLER AU - ANN M. REED Y1 - 2013/03/01 UR - http://www.jrheum.org/content/40/3/294.abstract N2 - Objective. To investigate B cell survival cytokine messenger RNA (mRNA) levels as biomarkers of idiopathic inflammatory myopathies (IIM). Methods. We measured and compared mRNA levels of B cell survival cytokines by quantitative real-time polymerase chain reaction in 98 patients with IIM, 38 patients with systemic lupus erythematosus, and 21 healthy controls. The cytokines were B cell-activating factor belonging to the tumor necrosis factor family (BAFF); ΔBAFF; and a proliferation-inducing ligand (APRIL); and their receptors BAFF-R, transmembrane activator and calcium modulator and cyclophilin ligand interactor, and B cell maturation antigen (BCMA). We also identified autoantibodies, including anti-Sm, anti-RNP, anti-SSA/Ro, anti-SSB/La, anti-topoisomerase 1, anti-hystidyl-tRNA synthetase, anti-ribosomal P, and anti-chromatin. Clinical disease activity was assessed by the International Myositis Assessment and Clinical Studies core set tool. We examined correlation of mRNA with disease activity, medication use, and autoantibodies. Results. We found a positive correlation of BAFF and ΔBAFF expression with 3 disease activity measures, with ΔBAFF having a stronger correlation. Similarly, anti-SSA/Ro-52 and/or anti-SSA/Ro-60 had a strong positive correlation with mRNA levels of BAFF and ΔBAFF, and with relative ratios of BAFF/APRIL and BCMA/BAFF-R. Conclusion. These findings highlight the potential importance of BAFF, ΔBAFF, and BAFF-R in the pathogenesis of IIM, and suggest an important role in the assessment of disease activity. ER -