Transglutaminase-dependent lymphocyte transformation in type 2 diabetes mellitus

The transglutaminase involvement in phytohaemagglutinin (PHA) stimulated lymphocyte transformation (measured as (3H)thymidine incorporation) was studied in lymphocytes from 20 patients with type 2 diabetes mellitus and 20 healthy controls by including in the system the specific transglutaminase pseudosubstrate monodansylthiacadaverine (MDTC). In the presence of MDTC, (3H)thymidine incorporation was significantly and concentration-dependently reduced in both groups but more pronouncedly in the diabetes patients. The MDTC concentration needed to give a 50% reduction of the PHA-stimulated (3H)thymidine incorporation was significantly lower in lymphocytes from diabetic patients than in those from controls (p less than 0.02). The data suggest impaired lymphocyte transglutaminase function in type 2 diabetes mellitus.