Molecular Profiling and Clonal Tracking of Secreted Rheumatoid Factors in Primary Sjögren's Syndrome

摘要: OBJECTIVE Rheumatoid factors (RFs) are associated with systemic disease in primary Sjogren's syndrome (SS) and may be pathogenic as mixed cryoglobulins. Current detection methods cannot resolve RFs at a molecular level. This study was undertaken to perform the first proteomic transcriptomic analysis of secreted membrane-bound IgM-RF SS identify unique heavy-chain peptide signatures for RF clonotype tracking. METHODS Purified heavy chains serum from 15 patients were subjected de novo mass spectrometric sequencing. The circulating B cell Ig repertoire determined by massively parallel sequencing IGH RNA matched peripheral blood mononuclear cells (n = 7). RF-specific third complementarity-determining region (CDR3) peptides identified searching sequences against corresponding sequence libraries. Heavy-chain CDR3 used biomarkers track clonotypes using quantitative multiple reaction monitoring. RESULTS Serum clonally restricted composed shared sets IgM variable (Ig VH ) 1-69, 3-15, 3-7, 3-74 subfamilies. Cryoprecipitable cryoglobulinemia (MC) distinguishable nonprecipitating higher frequency amino acid substitutions identification stereotypic transcripts. Potentially detected monitoring years before presented MC. Levels 4-34 decreased following immunosuppression remission CONCLUSION linked vasculitis have different profiles than RFs, suggesting underlying mechanisms production. combined omics workflow herein provides tracking removal clones.