Gene expression patterns in IgG4-RD before and after steroid treatment and healthy control groups. Homo sapiens

Transcriptome analysis in patients with IgG4-RD and healthy controls IgG4-related disease (IgG4-RD) is a new emerging disease entity characterized by elevated serum IgG4 concentrations and tissue tumefaction or infiltration by IgG4-positive plasma cells. At present, however, it is not clear whether IgG4-RD is caused by abnormalities in acquired immunity, like autoimmune diseases, or whether the excess production of IgG4 is a true cause of IgG4-RD or an epiphenomenon associated with inflammatory and/or allergic reactions. We therefore attempted to identify genes related to the pathogenesis or clinicopathology of IgG4-RD. Peripheral blood mononuclear cells (PBMCs) were obtained from patients with IgG4-RD before and after steroid therapy and from healthy controls. Total RNA was extracted and DNA microarray analysis was performed to screen for genes showing changes in expression. Overall design: To exclude any gender-related differences in gene expression, DNA microarray analysis was performed only on samples obtained from male patients and controls. Total RNA was reverse transcribed to cDNA using Ambion® WT Expression kits (Applied Biosystems, Foster City, CA), labeled with GeneChip® WT Terminal Labeling and Controls kits (Affymetrix, Santa Clara, CA), and hybridized to GeneChip® Human Gene 1.0 ST Arrays (Affymetrix), which include 28869 probes. Digitalized image data were processed using GeneChip® Operating Software (Affymetrix).