Immunotherapy Safe For Type 1 Diabetes

Immunotherapy with peptides modified T cell responses without interfering with residual β cell function in patients with type 1 diabetes, reducing the need to increase insulin use according to a recent, small study.

For their study, the researchers randomly assigned 27 participants with type 1 diabetes to either 6 months of immunotherapy or placebo at 2- or 4-week intervals. C-peptide levels were recorded at 3, 6, 9, and 12 months.
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Overall, β cells were not impaired in any way by the therapy, and no toxicity or negative effects were reported. Participants taking the placebo showed a significant decline in stimulated C-peptide at 3, 6, 9, and 12 months vs baseline, whereas no significant change was seen in the 4-weekly peptide group at 3, 6, 9, and 12 months or the 2-weekly group at 3, 6, and 9 months.

Daily insulin use in the placebo group increased by 50% over 12 months and remained the same in the intervention groups.

“C-peptide retention in treated subjects was associated with proinsulin-stimulated interleukin-10 production, increased FoxP3 expression by regulatory T cells, low baseline levels of activated β cell–specific CD8 T cells, and favorable β cell stress markers (proinsulin/C-peptide ratio). Thus, proinsulin peptide immunotherapy is safe, does not accelerate decline in β cell function, and is associated with antigen-specific and nonspecific immune modulation,” the researchers wrote.

—Michael Potts

Reference:

Ali MA, Liu Y, Arif S, et al. Metabolic and immune effects of immunotherapy with proinsulin peptide in human new-onset type 1 diabetes [published online August 9, 2017]. Sci Transl Med. Doi: https://doi.org/10.1126/scitranslmed.aaf7779.