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

Abstract

Abstract 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 ( IRt 0 : 0.53 ± 0.30 vs IRt 12 : 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 © 2007 John Wiley & Sons, Ltd.