A clinical trial was undertaken to determine whether intensive thymopentin administration enhances remission of insulin-dependent diabetes (IDDM) during the first year after diagnosis. Dosage with insulin was minimized with target control of blood glucose levels ≤7.8 mmol/l before meals. Remission was defined as a prolonged period after IDDM onset (not less than 3 months) characterized by a non-insulin-receiving (NIR) state in which target metabolic control was reached without administration of insulin and with a valid C-peptide response, evaluated after standard breakfast. Sixteen IDDM patients aged 12-31 years, recruited within 2 weeks of initiation of insulin therapy and within 5 weeks of onset of symptoms, were treated with intravenous (i.v.) thymopoietin32-36 pentapeptide (Thy) (1 mg/kg/body weight) for 7 days and twice per week for up to 3 months. A control IDDM group without initial significant differences in metabolic control parameters was also studied. No difference was observed between the two IDDM groups regarding the after-diagnosis normalization curve of HbA1c; mean daily glycemic level rates and ICA titer decreased during the observation. A reduction in anti-insulin anti-bodies (AIA) in Thy-treated patients was observed in comparison to conventionally treated IDDM starting from 6 months and reaching a reduction peak at 1 year (P≤0.02). As regards the NIR remission rate, it was significantly more accelerated in Thy-treated patients, reaching 43% at 6 months and 57% at 1 year vs 12% and 6.7% respectively in the control IDDM group (P range ≤0.05-0.02). Insulin requirement/kg/bodyweight was progressively significantly reduced in Thy-treated patients during the observation period (P range ≤0.01-0.001). Tac-positive cells and serum soluble interleukin-2 receptors (s IL2R) were significantly reduced in Thy-treated patients starting from 3 months, with a striking difference with respect to controls, which began after 6 months. Thy administration, known to enhance cell-mediated immunity, might increase NIR remission periods in very recently diagnosed IDDM patients, probably by inducing T-suppressor cell recruitment. This hypothesis is strongly suggested by the decrease in AIA production and IL 2 R levels in Thy-treated patients, which seem to be the main characteristics of their immunological pattern.
ASJC Scopus subject areas
- Immunology and Allergy