Inflammatory pathways in peripheral blood expression profile of recent-onset type 1 diabetes

Changes in innate and adaptive immunity occurring in and around pancreatic islets can also be observed in peripheral blood mononuclear cells (PBMC) of T1D patients in Caucasians. The aim of our study was to investigate whether gene expression patterns of PBMC could complement islet autoantibodies for T1D pathogenic mechanisms in the higlty admixed Brazilian population. Methods: We assessed global gene expression in PBMC from two groups mached for age, sex and BMI: The T1D group with 20 patients with recent-onset T1D (≤ 6 months from diagnosis, in a time when the autoimmune process is still highly active), testing positive for one or more islet autoantibodies and 20 islet autoantibody-negative healthy controls (Control group). Results: we identified 474 differentially expressed genes between groups. The most expressed genes in T1D group were mainly related to host defense, with inflammatory and anti-bacterial/antiviral effects ( LFT, DEFA4, DEFA1, CTSG, KCNMA1) as well as to cell cycle progression. Several of the downregulated genes in T1D influenced cellular repair, control of inflammation and immune tolerance. They were related to T helper 2 pathway, induction of FOXP3 expression (AREG) and immune tolerance (SMAD6). Conclusion: Our analysis suggested the activation of cell cycle/proliferation, anti-infectious and inflammatory pathways, indicating immune activation, whereas immunoregulatory pathways were downregulated in PBMC from recent-onset T1D patients. These alterations were elicited by a new genetic profile RNA Extraction was done fresh blood samples of 20 T1 diabetes patients and 20 healthy controls