An Inflammatory Gene-Expression Fingerprint in Monocytes of Autoimmune Thyroid Disease Patients

Context: In monocytes of patients with autoimmune diabetes, we recently identified a gene expression fingerprint of two partly overlapping gene clusters, a PDE4B-associated cluster (consisting of 12 core proinflammatory cytokine/compound genes), a FABP5-associated cluster (three core genes), and a set of nine overlapping chemotaxis, adhesion, and cell assembly genes correlating to both PDE4B and FABP5. Objective: Our objective was to study whether a similar monocyte inflammatory fingerprint as found in autoimmune diabetes is present in autoimmune thyroid disease (AITD). Design and Patients: Quantitative PCR was used for analysis of 28 genes in monocytes of 67 AITD patients and 70 healthy controls. The tested 28 genes were the 24 genes previously found abnormally expressed in monocytes of autoimmune diabetes patients plus four extra genes found in whole-genome analysis of monocytes of AITD patients reported here. Results: Monocytes of 24% of AITD and 50% of latent autoimmune diabetes of adults (LADA) patients shared an inflammatory fingerprint consisting of the set of 24 genes of the PDE4B, FABP5, and overlapping gene sets. This study in addition revealed that FCAR, the gene for the Fcα receptor I, and PPBP, the gene for CXCL7, were part of this proinflammatory monocyte fingerprint. Conclusions: Our study provides an important tool to determine a shared, specific proinflammatory state of monocytes in AITD and LADA patients, enabling further research into the role of such proinflammatory cells in the failure to preserve tolerance in these conditions and of key fingerprint genes involved.