CONTINUED INSULIN DEPENDENCE DESPITE NORMAL RANGE INSULIN SENSITIVITYAND INSULIN CONNECTING PEPTIDE LEVELS IN A KIDNEY ISLET TRANSPLANT PATIENT

OBJECTIVE - The majority of islet transplant recipients remain insulin -requiring, although many have near-normal connecting peptide (CP) lev els. Insulin resistance may be one possible cause of the continuing ne ed for exogenous insulin in islet transplant recipients. To assess thi s, we have studied the insulin sensitivity index (S-I) in one patient with near-normal CP levels after islet transplant who remained insulin -requiring. RESEARCH DESIGN AND METHODS - The islet transplant recipie nt is a 36-year-old woman with no residual CP who received a kidney tr ansplant, followed 7 days later by an islet transplant. The islets wer e infused into the liver via the umbilical vein. Induction immunosuppr ession consisted of OKT3, prednisone, cyclosporin A, and azathioprine, with maintenance on the latter three. RESULTS - Maximum CP levels aft er a standardized Sustacal meal were 2.09, 1.18, 0.85, and 0.81 nmol/l al 1, 6, 18, and 24 months posttransplant, respectively. Insulin requ irements at the same times were 0.27, 0.45, 0.49, and 0.62 U . kg(-1). d(-1), while S-I was 36.3, 53.3, and 13.2 min(-1). nmol(-1). ml at 6, 18, and 24 months, respectively. This compares with S-I values of 43. 3 +/- 10.0 min(-1). nmol(-1) mi for normal subjects. CONCLUSIONS - Thi s patient had near-normal S-I and CP levels, but she was unable to dis continue insulin therapy, suggesting that other factors are critical. Despite this, she maintained normal or near-normal glycated hemoglobin s, indicating metabolic benefit from the islet transplant.