The immunogenetic disorders of Type 1 diabetes were assessed by measuring the serum levels of soluble interleukin-2 receptors (sIL-2R) by enzyme-linked immunosorbent assay. Type 1 diabetic patients had significantly higher levels of sIL-2R in their sera (381±47 U/m/) than normal subjects (220±29U/m/, p<0.005). However, Type 2 (non-insulin-dependent) diabetic patients did not (260±58U/m/, p: NS). The mean level of sIL-2R on islet cell antibody (ICA)-positive Type 1 diabetic patients (501±73U/mi) was significantly higher than that in ICA-negative patients (256±43U/m/, p<0.01). These elvevated levels of sIL-2R in ICA-positive patients were observed in both newly diagnosed (within 3 months after onset) and long-term (>1yr) Type 1 diabetic patients (498±110U/m/ and 503±101U/m/, respectively). Neither the plasma glucose nor the glycosylated haemoglobin level was correlated with the level of sIL-2R. These results suggest a significant role of activation of IL-2R-positive cells in Type 1 diabetes.
The authors demonstrated that in most non-obese NIDDM patients with secondary failure on sulfonylurea, 3 injections of sufficient regular insulin before each meal enabled to regulate glycemia throughout the day. Out of 25 insulin-treated non-obese NIDDM patients with secondary failure on sulfonylurea, 5 showed a high fasting plasma glucose level (160±11mg/dl) in spite of having a normal plasma glucose concentration at 10 PM (113±20mg/dl). In these patients, the urinary C-peptide excretion rate from 10 PM to 7 AM was 0.56±0.49μg/h [age: 57.8±12.3 (M±SD), estimated durataion of DM 17.0±7.7, duration of sulfonylurea administration: 14.8±6.3years] These patients were given glibenclamide 1.25-5mg/day at 10 PM as well as regular insulin 30 min before each meal. After combined insulin-sulfonylurea therapy, complete normalization of both meal-related and pre-breakfast glycemia (109±29mg/dl) was established and the urinary C-peptide excretion rate from 10PM to 7 AM increased to 1.50±0.64μg/h. It was demostrated that, in non-obese NIDDM patients with secondary failure on sulfonylurea whose basal insulin secretion was decreased, treatment with prandial regular insulin injections and sulfonylurea before sleep could control glycemia throughout the day.