WEDNESDAY, April 13 (HealthDay News) -- Nasal insulin does not affect β-cell function, but does induce immune tolerance to insulin, according to a study published in the April issue of Diabetes.
Spiros Fourlanous, Ph.D., from the Walter and Eliza Hall Institute of Medical Research in Parkville, Australia, and colleagues assessed whether administration of nasal insulin induces tolerance to insulin in patients with type 1 diabetes who are subsequently treated with injected insulin. Fifty-two adults with recent-onset, noninsulin-requiring type 1 diabetes were randomly allocated to receive nasal insulin or a nasal placebo for 12 months, and 23 of them of them went on to be treated with injected insulin. Fasting blood glucose, serum C-peptide, and serum antibodies to islet antigens were recorded three times a month during a 24-month follow-up period. The response of T-cells to proinsulin was measured in a small cohort.
The investigators found that β-cell function decreased by 35 percent, and was not significantly different in the two groups. Although metabolic parameters were similar for patients treated with nasal insulin and controls, those who received nasal insulin had a significantly blunted insulin antibody response. Following treatment with nasal insulin, the interferon-γ response to proinsulin was suppressed.
"Our finding that the antibody response to subcutaneous insulin was suppressed by prior treatment with nasal insulin is the first evidence for immune tolerance induction to an autoantigen demonstrated by rechallenge in humans," the authors write.
Abstract
Full Text (subscription or payment may be required)
