BACKGROUND. Type 1 diabetes (T1D) results from destruction of pancreatic β cells by autoreactive effector T cells. We hypothesized that the immunomodulatory drug alefacept would result in targeted quantitative and qualitative changes in effector T cells and prolonged preservation of endogenous insulin secretion by the remaining β cells in patients with newly diagnosed T1D.METHODS. In a multicenter, randomized, double-blind, placebo-controlled trial, we compared alefacept (two 12-week courses of 15 mg/wk i.m., separated by a 12-week pause) with placebo in patients with recent onset of T1D. Endpoints were assessed at 24 months and included meal-stimulated C-peptide AUC, insulin use, hypoglycemic events, and immunologic responses.RESULTS. A total of 49 patients were enrolled. At 24 months, or 15 months after the last dose of alefacept, both the 4-hour and the 2-hour C-peptide AUCs were significantly greater in the treatment group than in the control group (P = 0.002 and 0.015, respectively). Exogenous insulin requirements were lower (P = 0.002) and rates of major hypoglycemic events were about 50% reduced (P < 0.001) in the alefacept group compared with placebo at 24 months. There was no apparent betweengroup difference in glycemic control or adverse events. Alefacept treatment depleted CD4 + and CD8 + central memory T cells (Tcm) and effector memory T cells (Tem) (P < 0.01), preserved Tregs, increased the ratios of Treg to Tem and Tcm (P < 0.01), and increased the percentage of PD-1 + CD4+ Tem and Tcm (P < 0.01).CONCLUSIONS. In patients with newly diagnosed T1D, two 12-week courses of alefacept preserved C-peptide secretion, reduced insulin use and hypoglycemic events, and induced favorable immunologic profiles at 24 months, well over 1 year after cessation of therapy.TRIAL REGISTRATION. https://clinicaltrials.gov/ NCT00965458.FUNDING. NIH and Astellas.

Release of glucose by liver and kidney are both increased in diabetic animals. Although the overall release of glucose into the circulation is increased in humans with diabetes, excessive release of glucose by either their liver or kidney has not as yet been demonstrated. The present experiments were therefore undertaken to assess the relative contributions of hepatic and renal glucose release to the excessive glucose release found in type 2 diabetes. Using a combination of isotopic and balance techniques to determine total systemic glucose release and renal glucose release in postabsorptive type 2 diabetic subjects and age-weight-matched nondiabetic volunteers, their hepatic glucose release was then calculated as the difference between total systemic glucose release and renal glucose release. Renal glucose release was increased nearly 300% in diabetic subjects (321 Ϯ 36 vs. 125 Ϯ 15 mol/min, P Ͻ 0.001). Hepatic glucose release was increased ‫ف‬ 30% ( P ϭ 0.03), but increments in hepatic and renal glucose release were comparable (2.60 Ϯ 0.70 vs. 2.21 Ϯ 0.32, mol и kg Ϫ 1 и min Ϫ 1 , respectively, P ϭ 0.26). Renal glucose uptake was markedly increased in diabetic subjects (353 Ϯ 48 vs. 103 Ϯ 10 mol/min, P Ͻ 0.001), resulting in net renal glucose uptake in the diabetic subjects (92 Ϯ 50 mol/ min) versus a net output in the nondiabetic subjects (21 Ϯ 14 mol/min, P ϭ 0.043). Renal glucose uptake was inversely correlated with renal FFA uptake ( r ϭ Ϫ 0.51, P Ͻ 0.01), which was reduced by ‫ف‬ 60% in diabetic subjects (10.9 Ϯ 2.7 vs. 27.0 Ϯ 3.3 mol/min, P Ͻ 0.002). We conclude that in type 2 diabetes, both liver and kidney contribute to glucose overproduction and that renal glucose uptake is markedly increased. The latter may suppress renal FFA uptake via a glucose-fatty acid cycle and explain the accumulation of glycogen commonly found in the diabetic kidney. ( J. Clin. Invest. 1998. 102:619-624.)

. Role of human liver, kidney, and skeletal muscle in postprandial glucose homeostasis. Am J Physiol Endocrinol Metab 282: E419-E427, 2002; 10.1152/ ajpendo.00032.2001.-Recent studies indicate a role for the kidney in postabsorptive glucose homeostasis. The present studies were undertaken to evaluate the role of the kidney in postprandial glucose homeostasis and to compare its contribution to that of liver and skeletal muscle. Accordingly, we used the double isotope technique along with forearm and renal balance measurements to assess systemic, renal, and hepatic glucose release as well as glucose uptake by kidney, skeletal muscle, and splanchnic tissues in 10 normal volunteers after ingestion of 75 g of glucose. We found that, during the 4.5-h postprandial period, 22 Ϯ 2 g (30 Ϯ 3% of the ingested glucose) were initially extracted by splanchnic tissues. Of the remaining 53 Ϯ 2 g that entered the systemic circulation, 19 Ϯ 3 g were calculated to have been taken up by skeletal muscle and 7.5 Ϯ 1.7 g by the kidney (26 Ϯ 3 and 10 Ϯ 2%, respectively, of the ingested glucose). Endogenous glucose release during the postprandial period (16 Ϯ 2 g), calculated as the difference between overall systemic glucose appearance and the appearance of ingested glucose in the systemic circulation, was suppressed 61 Ϯ 3%. Surprisingly, renal glucose release increased twofold (10.6 Ϯ 2.5 g) and accounted for ϳ60% of postprandial endogenous glucose release. Hepatic glucose release (6.7 Ϯ 2.2 g), the difference between endogenous and renal glucose release, was suppressed 82 Ϯ 6%. These results demonstrate a hitherto unappreciated contribution of the kidney to postprandial glucose homeostasis and indicate that postprandial suppression of hepatic glucose release is nearly twofold greater than had been calculated in previous studies (42 Ϯ 4%), which had assumed that there was no renal glucose release. We postulate that increases in postprandial renal glucose release may play a role in facilitating efficient liver glycogen repletion by permitting substantial suppression of hepatic glucose release.gluconeogenesis; glycogenolysis; glucose disposal CONSIDERABLE INFORMATION has recently accumulated regarding postprandial glucose homeostasis. It appears that about one-third of ingested carbohydrate is immediately taken up by splanchnic tissues (5, 22, 33-35, 37, 38, 44, 60). Of the remaining two-thirds of the ingested carbohydrate that enters the systemic circulation, some is extracted by the liver (23), but most is taken up by peripheral tissues. Limb balance measurements indicate that skeletal muscle is the predominant site for this peripheral glucose disposal, being responsible for about one-fourth of the ingested carbohydrate (5, 26, 33-35, 37, 38, 44). The fate of the remaining 40% of the ingested carbohydrate is less clear.In addition to tissue uptake of ingested carbohydrate, another important factor for postprandial glucose homeostasis is suppression of the release of glucose endogenously produced by gluconeogenesis and breakdown of ...

Summary Background Type 1 diabetes (T1D) results from autoimmune targeting of the pancreatic beta cells, likely mediated by effector memory T cells (Tems). CD2, a T cell surface protein highly expressed on Tems, is targeted by the fusion protein alefacept, depleting Tems and central memory T cells (Tcms). We hypothesized that alefacept would arrest autoimmunity and preserve residual beta cells in newly diagnosed T1D. Methods The T1DAL study is a phase II, double-blind, placebo-controlled trial that randomised T1D patients 12-35 years old within 100 days of diagnosis, 33 to alefacept (two 12-week courses of 15 mg IM per week, separated by a 12-week pause) and 16 to placebo, at 14 US sites. The primary endpoint was the change from baseline in mean 2-hour C-peptide area under the curve (AUC) at 12 months. This trial is registered with ClinicalTrials.gov, number NCT00965458. Findings The mean 2-hour C-peptide AUC at 12 months increased by 0.015 nmol/L (95% CI -0.080 to 0.110 nmol/L) in the alefacept group and decreased by 0.115 nmol/L (95% CI -0.278 to 0.047) in the placebo group, which was not significant (p=0.065). However, key secondary endpoints were met: the mean 4-hour C-peptide AUC was significantly higher (p=0.019), and daily insulin use and the rate of hypoglycemic events were significantly lower (p=0.02 and p<0.001, respectively) at 12 months in the alefacept vs. placebo groups. Safety and tolerability were comparable between groups. There was targeted depletion of Tems and Tcms, with sparing of naïve and regulatory T cells (Tregs). Interpretation At 12 months, alefacept preserved the 4-hour C-peptide AUC, lowered insulin use, and reduced hypoglycemic events, suggesting a signal of efficacy. Depletion of memory T cells with sparing of Tregs may be a useful strategy to preserve beta cell function in new-onset T1D.

The mechanisms responsible for the deterioration in glucose tolerance associated with protease inhibitorcontaining regimens in HIV infection are unclear. Insulin resistance has been implicated as a major factor, but the affected tissues have not been identified. Furthermore, ␤-cell function has not been evaluated in detail. The present study was therefore undertaken to assess the effects of protease inhibitor-containing regimens on hepatic, muscle, and adipose tissue insulin sensitivity as well as pancreatic ␤-cell function. We evaluated ␤-cell function in addition to glucose production, glucose disposal, and free fatty acid (FFA) turnover using the hyperglycemic clamp technique in combination with isotopic measurements in 13 HIV-infected patients before and after 12 weeks of treatment and in 14 normal healthy volunteers. ␤-Cell function and insulin sensitivity were also assessed by homeostasis model assessment (HOMA). Treatment increased fasting plasma glucose concentrations in all subjects (P < 0.001). Insulin sensitivity as assessed by HOMA and clamp experiments decreased by ϳ50% (P < 0.003). Postabsorptive glucose production was appropriately suppressed for the prevailing hyperinsulinemia, whereas glucose clearance was reduced (P < 0.001). ␤-Cell function decreased by ϳ50% (P ‫؍‬ 0.002), as assessed by HOMA, and firstphase insulin release decreased by ϳ25%, as assessed by clamp data (P ‫؍‬ 0.002). Plasma FFA turnover and clearance both increased significantly (P < 0.001). No differences at baseline or in responses after treatment were observed between drug naïve patients who were started on a nucleoside reverse transcriptase inhibitor (NRTI) plus a protease inhibitor and patients who had been on long-term NRTI treatment and had a protease inhibitor added. The present study indicates that protease inhibitor-containing regimens impair glucose tolerance in HIV-infected patients by two mechanisms: 1) inducement of peripheral insulin resistance in skeletal muscle and adipose tissue and 2) impairment of the ability of the ␤-cell to compensate. Diabetes 52: 918 -925, 2003 U se of protease inhibitors has remarkably improved long-term survival after HIV infection (1,2). However, up to 60% of HIV-infected patients treated with these agents develop either impaired glucose tolerance (IGT) or type 2 diabetes (3-6), and it now appears to be well established that regimens including protease inhibitors are associated with insulin resistance (2,5,7,8). Noor et al. (9,10) have shown that acute and 4-week protease inhibitor exposure of normal volunteers reduces glucose disposal during euglycemichyperinsulinemic clamp experiments. Moreover, in vitro studies have demonstrated that protease inhibitors reduce insulin-stimulated glucose uptake in adipocytes and skeletal muscle (11,12).Knowledge of the mechanisms responsible for deterioration in glucose tolerance during protease inhibitorcontaining regimens is still incomplete. It is unclear whether protease inhibitors adversely affect pancreatic ␤-cell function (4,8) and what effec...