Long-term safety of α-1 antitrypsin therapy in children and adolescents with Type 1 diabetes

Promising findings of α-1 antitrypsin (AAT) intervention in mice models of Type 1 diabetes (T1D) led researchers to investigate AAT as a therapeutic modality for β-cell preservation in recent-onset T1D patients. Our prospective, open-label Phase I/II extension study demonstrated that the administration of multiple repeated AAT infusions (up to 36) to AAT-sufficient pediatric T1D patients is safe and well-tolerated. Long-term surveillance of participants (up to 5 years) from diabetes onset revealed normal growth and pubertal progression through adolescence to attainment of full puberty and near adult height. No serious adverse events, clinical or laboratory abnormalities were reported. Given its safety profile, AAT may be an individualized-tailored innovative immunotherapy in AAT-sufficient pediatric patients with diverse immune-related medical conditions. ClinicalTrials.gov Identifier: NCT01661192.

Clinical application of regulatory T cells in type 1 diabetes

Regulatory T cells (Tregs) are responsible for the maintenance of peripheral tolerance. Animal studies have shown that administration of Tregs can prevent type 1 diabetes (DM1). Several clinical trials attempted to induce Tregs with various agents, and thus provide long-term tolerance of β cells in DM1. Nevertheless, most of these studies have focused on clinical parameters (e.g. C-peptide) and not Treg numbers nor their function after treatment. Therefore, it is not possible to conclude if the majority of these therapies failed because the drugs did not induce Tregs, or if they failed despite Treg expansion. The current knowledge regarding Tregs, along with our experience in Treg therapy of patients with graft versus host disease, prompted us to use ex vivo expanded Tregs in 10 children with recent-onset DM1. No adverse effects in the treated individuals were observed. There was a significant increase in Treg number in peripheral blood immediately after the treatment administration, while the first clinical differences between treated and control patients were observed 4 months after Treg injection. Treated individuals had higher C-peptide levels and lower insulin requirements than non-treated children. Eleven months after diagnosis of DM1, there are still 2 individuals who are independent of exogenous insulin. These results indicate that autologous Tregs are a safe and well-tolerated therapy in children with DM1, which can inhibit or delay the destruction of pancreatic β cells. Additionally, Tregs can be a useful tool for local protection of transplanted pancreatic islets. Isolation and expansion of antigen-specific Tregs is one of the directions for future studies on cellular therapy of DM1.