There is a need for biomarkers to monitor the development and progression of type 1 DM. We analyzed mRNA expression levels for granzyme B, perforin, fas ligand, TNF-α, IFN-γ, Foxp3, IL-10, TGF-β, IL-4, IL-6, IL-17, Activation-induced cytidine deaminase (AID) and Immunoglobulin G gamma chain (IgG) genes in peripheral blood of at-risk, new-onset and long-term type 1 DM, and healthy controls. The majority of the genes were suppressed in long-term type 1 DM compared to controls and new-onset patients. IFN-γ, IL-4 and IL-10 mRNA levels were significantly higher in new-onset compared to at-risk and long-term groups. There was decreased mRNA expression for AID and IgG and up-regulation of IFN-γ with age in controls. Data suggest an overall depressed immunity in long-term type 1 DM. Increased gene expression levels for IFN-γ, IL-4 and IL-10 in new-onset patients from at-risk patients might be used as potential markers for progression of the disease.