title: BAFF expression correlates with idiopathic inflammatory myopathy disease activity measures and autoantibodies.
abstract: 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.
  
  
  CONCLUSIONS
  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.
authors: Division of Rheumatology, Mayo Clinic, Rochester, Minnesota 55905, USA.
authors: Consuelo M
authors: CM
authors: López De Padilla
authors: Kelly T
authors: KT
authors: McNallan
authors: Cynthia S
authors: CS
authors: Crowson
authors: Hatice
authors: H
authors: Bilgic
authors: Richard J
authors: RJ
authors: Bram
authors: Molly S
authors: MS
authors: Hein
authors: Steven R
authors: SR
authors: Ytterberg
authors: Shreyasee
authors: S
authors: Amin
authors: Erik J
authors: EJ
authors: Peterson
authors: Emily C
authors: EC
authors: Baechler
authors: Ann M
authors: AM
authors: Reed
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001323:Autoantibodies / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D053264:B-Cell Activating Factor / Q000235:genetics / Q000378:metabolism*; D053265:B-Cell Activation Factor Receptor / Q000235:genetics / Q000378:metabolism; D053301:B-Cell Maturation Antigen / Q000235:genetics / Q000378:metabolism; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009220:Myositis / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D012720:Severity of Illness Index; D053303:Transmembrane Activator and CAML Interactor Protein / Q000235:genetics / Q000378:metabolism; D053300:Tumor Necrosis Factor Ligand Superfamily Member 13 / Q000235:genetics / Q000378:metabolism
chemical_list: D001323:Autoantibodies; D053264:B-Cell Activating Factor; D053265:B-Cell Activation Factor Receptor; D053301:B-Cell Maturation Antigen; C114631:TNFSF13 protein, human; C505719:TNFSF13B protein, human; D053303:Transmembrane Activator and CAML Interactor Protein; D053300:Tumor Necrosis Factor Ligand Superfamily Member 13