Immunobiology of Diabetes and Tuberculosis

The study hypothesis is that type 2 diabetics have abnormal cell-mediated immunity to tuberculosis manifesting as altered cytokine responses by peripheral blood mononuclear cells (PBMCs). This hypothesis will be tested using the live tuberculosis vaccine, Bacille Calmette-Guerin (BCG), in U.S.-born type 2 diabetics and nondiabetics. The investigators will control for potential confounding by age, sex, race, comorbidities, and select medications. Expression of key cytokines will be measured with real-time polymerase chain reaction.

The project has three specific aims: Specific Aim 1: To assess differences between the study groups in cytokine expression before and after BCG vaccination. The investigators will determine within-individual variability in cytokine measurements and describe the kinetics of cytokine response to BCG. Peak response levels, time to peak, and patterns of cytokines expressed will be compared. Specific Aim 2: To evaluate the effect of hyperglycemia on the cytokine response of type 2 diabetics. The investigators will evaluate whether levels of hemoglobin A1C (HbA1C) are associated with degree of cytokine response and test if type 2 diabetics who have good glucose control are different from nondiabetics. Specific Aim 3: To evaluate the effect of testing PBMCs from diabetics outside of their diabetic milieu. Investigators will compare the BCG-specific cytokine responses of PBMCs stimulated in normal medium, PBMCs stimulated in glucose correlating to the person's most recent HbA1C, and whole blood samples.

Persons with no diagnosis of diabetes and negative diabetes screening labs. Received biological intervention: BCG.

Both arms: diabetics and nondiabetics will receive vaccination in the upper arm with a 0.1-mg intradermal dose of a single strain of BCG (Mycobax, Sanofi-Aventis), which is FDA approved for this indication.

Participants had baseline tuberculin testing (TST), followed by BCG vaccination, and at 5 months after vaccination, study participants had repeat tuberculin skin testing done.

Blood was sampled at times 0, 2, 4, 6, 8, 12, 16, and 20 weeks post BCG vaccination and Interferon gamma production was measured as change from pre-vaccination baseline. Timeline of peak IFn-g response was measured for both study groups.

Inclusion Criteria:Type 2 diabetes or healthy individual Able to give consent US-born Age 30-65 Exclusion Criteria:* Immunosuppressive disease Immunosuppressive medications Pregnancy Renal failure Advanced pulmonary disease Prior BCG vaccination Prior TB infection Type 1 diabetes