Sardinian Type 1 diabetes patients, Transthyretin and Mycobacterium avium subspecies paratuberculosis infection.

Mycobacterium avium subsp. paratuberculosis (MAP) is the cause of Johne’s disease, an enteric
granulomatous disease. Recently, MAP has been associated with different autoimmune diseases such as Crohn’s
disease, type 1 diabetes (T1D) and multiple sclerosis. Transthyretin (TTR) is a plasma transport protein for thyroid
hormone and forms a complex with retinol-binding protein. Reduced TTR plasma levels in MAP infected ovines
have been reported.
TTR exerts also a functional role in the pancreas promoting insulin release and protecting β-cells from death.
Our objective was to identify a protein that could be used as a diagnostic marker of T1D for determining disease
progression and monitoring at-risk patients. We postulate that serological TTR levels would be reduced in T1D MAP
exposed patients. Our hypothesis is based on the observation of cases of T1D patients with decreased TTR levels
beside the reduced TTR plasma levels in ovines with Johne’s disease.
We quantified the plasma protein levels of TTR in 50 people with T1D and 51 age-matched healthy controls (HCs)
by means of enzyme-linked immunosorbent assays (ELISA).