Pancreatic scintigraphy with 99mTc-interleukin-2 at diagnosis of type 1 diabetes and after 1 year of nicotinamide therapy.

BACKGROUND: To evaluate the clinical utility of pancreatic scintigraphy with 99mTc-interleukin-2 to identify Type 1 diabetic patients with pancreatic inflammation at diagnosis.
METHODS: 99mTc-interleukin-2 scintigraphy was performed on 42 newly diagnosed Type 1 diabetic patients, before and after 1 year of treatment with nicotinamide (25 or 50 mg/kg/day) in addition to intensive insulin therapy. Metabolic status was monitored every 3 months for 1 year. Sixteen normal subjects were studied as control.
RESULTS: Significant pancreatic accumulation of 99mTc-interleukin-2 was found in 31% of the patients at the time of diagnosis. Patients positive or negative for pancreatic accumulation of interleukin-2 scintigraphy did not show any difference in metabolic or immunologic parameters at diagnosis. Positive patients, however, showed higher C-peptide values at 3 months and lower insulin requirement at 1 year, compared to negative patients (insulin requirement (IR): 0.33+/-0.11 vs 0.67+/-0.24 IU/kg/day, positive vs negative patients; p=0.0001); patients positive to IL2 scintigraphy treated with nicotinamide at 25 mg/kg were the only group showing a significant reduction in IR 1 year after diagnosis (IRt0: 0.53+/-0.30 vs IRt12: 0.28+/-0.07 IU/kg/day; p=0.013). After 1 year, all the positive patients showed a significant decrease in pancreatic uptake of 99mTc-interleukin-2 (P/B: 7.87+/-2.28 at diagnosis vs 5.00+/-1.23 after 1 year; p<0.0001 paired t-test).
CONCLUSION: 99mTc-interleukin-2 scintigraphy at diagnosis of Type 1 diabetes may identify patients with pancreatic inflammation. In such patients, treated with nicotinamide at 25 mg/kg, insulin requirement and pancreatic inflammation after 1 year were significantly reduced suggesting that IL2 scintigraphy may be of potential use for assessing the autoimmune phenomena in endocrine pancreas. Copyright (c) 2007 John Wiley & Sons, Ltd.