A phase 2 randomized trial with autologous polyclonal expanded regulatory T cells in children with new-onset type 1 diabetes.

CD4+CD25hiCD127lo/-FOXP3+ regulatory T cells (Tregs) play a key role in preventing autoimmunity. In autoimmune type 1 diabetes (T1D), adoptive transfer of autologous polyclonal Tregs has been shown to be safe in adults in phase 1 clinical trials. We explored factors contributing to efficacy of autologous polyclonal expanded Tregs (expTregs) in a randomized phase 2 multi-center, double-blind, clinical trial (Sanford/Lisata Therapeutics T-Rex phase 2 trial, ClinicalTrials.gov NCT02691247). One hundred ten treated children and adolescents with new-onset T1D were randomized 1:1:1 to high-dose (20 × 106 cells/kilogram) or low-dose (1 × 106 cells/kilogram) treatments or to matching placebo. Cytometry as well as bulk and single-cell RNA sequencing were performed on selected expTregs and peripheral blood samples from participants. The single doses of expTregs were safe but did not prevent decline in residual ß cell function over 1 year compared to placebo (P = 0.94 low dose, P = 0.21 high dose), regardless of age or baseline C-peptide. ExpTregs were highly activated and suppressive in vitro. A transient increase of activated memory Tregs was detectable 1 week after infusion in the high-dose cohort, suggesting effective transfer of expTregs. However, the in vitro fold expansion of expTregs varied across participants, even when accounting for age, and lower fold expansion and its associated gene signature were linked with better C-peptide preservation regardless of Treg dose. These results suggest that a single dose of polyclonal expTregs does not alter progression in T1D; instead, Treg quality may be an important factor.

Islet autoantibodies as precision diagnostic tools to characterize heterogeneity in type 1 diabetes: a systematic review.

BACKGROUND: Islet autoantibodies form the foundation for type 1 diabetes (T1D) diagnosis and staging, but heterogeneity exists in T1D development and presentation. We hypothesized that autoantibodies can identify heterogeneity before, at, and after T1D diagnosis, and in response to disease-modifying therapies. METHODS: We systematically reviewed PubMed and EMBASE databases (6/14/2022) assessing 10 years of original research examining relationships between autoantibodies and heterogeneity before, at, after diagnosis, and in response to disease-modifying therapies in individuals at-risk or within 1 year of T1D diagnosis. A critical appraisal checklist tool for cohort studies was modified and used for risk of bias assessment. RESULTS: Here we show that 152 studies that met extraction criteria most commonly characterized heterogeneity before diagnosis (91/152). Autoantibody type/target was most frequently examined, followed by autoantibody number. Recurring themes included correlations of autoantibody number, type, and titers with progression, differing phenotypes based on order of autoantibody seroconversion, and interactions with age and genetics. Only 44% specifically described autoantibody assay standardization program participation. CONCLUSIONS: Current evidence most strongly supports the application of autoantibody features to more precisely define T1D before diagnosis. Our findings support continued use of pre-clinical staging paradigms based on autoantibody number and suggest that additional autoantibody features, particularly in relation to age and genetic risk, could offer more precise stratification. To improve reproducibility and applicability of autoantibody-based precision medicine in T1D, we propose a methods checklist for islet autoantibody-based manuscripts which includes use of precision medicine MeSH terms and participation in autoantibody standardization workshops.

Islet autoantibodies are markers found in the blood when insulin-producing cells in the pancreas become damaged and can be used to predict future development of type 1 diabetes. We evaluated published literature to determine whether characteristics of islet antibodies (type, levels, numbers) could improve prediction and help understand differences in how individuals with type 1 diabetes respond to treatments. We found existing evidence shows that islet autoantibody type and number are most useful to predict disease progression before diagnosis. In addition, the age when islet autoantibodies first appear strongly influences rate of progression. These findings provide important information for patients and care providers on how islet autoantibodies can be used to understand future type 1 diabetes development and to identify individuals who have the potential to benefit from intervention or prevention therapy.

Pediatric Endocrine Society Statement on Considerations for Use of Teplizumab (Tzield™) in Clinical Practice.

Teplizumab (TzieldTM, Provention Bio), a monoclonal antibody directed at t-cell marker CD3, is the first medication approved by the FDA to delay progression from Stage 2 to Stage 3 type 1 diabetes (T1D). To date, the overwhelming majority of pediatric endocrinologists do not have experience using immunotherapeutics and seek guidance the use of teplizumab in clinical practice. To address this need, the Pediatric Endocrine Society (PES) Diabetes Special Interest Group (Diabetes SIG) and Drug and Therapeutics Committee assembled a task force to review clinical trial data and solicit expert recommendations on the approach to teplizumab infusions. We present considerations on all aspects of teplizumab administration, utilizing evidence where possible and providing a spectrum of expert opinions on unknown aspects. We discuss patient selection and prescreening, highlighting the safety and considerations for monitoring and treatment of side effects. We propose a schedule of events, a protocol for administration and discuss practice management aspects. We advocate for the need for further long-term systematic surveillance studies to continue evaluating the efficacy and safety of teplizumab.

Disease-modifying therapies and features linked to treatment response in type 1 diabetes prevention: a systematic review.

BACKGROUND: Type 1 diabetes (T1D) results from immune-mediated destruction of insulin-producing beta cells. Prevention efforts have focused on immune modulation and supporting beta cell health before or around diagnosis; however, heterogeneity in disease progression and therapy response has limited translation to clinical practice, highlighting the need for precision medicine approaches to T1D disease modification. METHODS: To understand the state of knowledge in this area, we performed a systematic review of randomized-controlled trials with ≥50 participants cataloged in PubMed or Embase from the past 25 years testing T1D disease-modifying therapies and/or identifying features linked to treatment response, analyzing bias using a Cochrane-risk-of-bias instrument. RESULTS: We identify and summarize 75 manuscripts, 15 describing 11 prevention trials for individuals with increased risk for T1D, and 60 describing treatments aimed at preventing beta cell loss at disease onset. Seventeen interventions, mostly immunotherapies, show benefit compared to placebo (only two prior to T1D onset). Fifty-seven studies employ precision analyses to assess features linked to treatment response. Age, beta cell function measures, and immune phenotypes are most frequently tested. However, analyses are typically not prespecified, with inconsistent methods of reporting, and tend to report positive findings. CONCLUSIONS: While the quality of prevention and intervention trials is overall high, the low quality of precision analyses makes it difficult to draw meaningful conclusions that inform clinical practice. To facilitate precision medicine approaches to T1D prevention, considerations for future precision studies include the incorporation of uniform outcome measures, reproducible biomarkers, and prespecified, fully powered precision analyses into future trial design.

Type 1 diabetes (T1D) is a condition that results from the destruction of a type of cell in the pancreas that produces the hormone insulin, leading to lifelong dependence on insulin injections. T1D prevention remains a challenging goal, largely due to the immense variability in disease processes and progression. Therapies tested to date in medical research settings (clinical trials) work only in a subset of individuals, highlighting the need for more tailored prevention approaches. We reviewed clinical trials of therapies targeting the disease process in T1D. While the overall quality of trials was high, studies testing individual features affecting responses to treatments were low. This review reveals an important need to carefully plan high-quality analyses of features that affect treatment response in T1D, to ensure that tailored approaches may one day be applied to clinical practice.

Comparison of Visual Methods to Reanalyze Provocative Test Data from Randomized Controlled Clinical Trials in New- or Recent-Onset Type 1 Diabetes.

INTRODUCTION: Over the last 13 years, the Immune Tolerance Network (ITN), has conducted trials of agents to abrogate the autoimmunity underlying type 1 diabetes. Primary endpoints center on the change of C-peptide production during mixed meal tolerance tests (MMTT), measured as the area under the curve (AUC) or AUC mean over 2-3 years. Studies permit rapid-acting insulin until a few hours before the MMTT, and thus do not exclude overnight hyperglycemia prior to testing. We hypothesize that overnight or fasting hyperglycemia will deplete pre-formed insulin and impact measurements of first-phase insulin secretion and C-peptide AUC. METHODS: Publicly available, deidentified, subject-level data were obtained from ITN TrialShare. We developed several graphical analyses to reexamine results from each MMTT including combined glucose and C-peptide response curves, the centroids of polygons of MMTT timepoints, and ratios comparing extents of excursions of glucose and c-peptide production. RESULTS: We have applied these graphical analyses to 1161 MMTT from 245 subjects in 8 studies. Graphical analyses of MMTT results for individuals over the course of the follow-up period reflect the expected loss of c-peptide and higher blood glucose during MMTT; centroids move accordingly, upwards and leftwards. CONCLUSIONS: We were able to analyze MMTT data from ITN studies with several graphical analyses. We are poised to apply these approaches to test our central hypothesis by comparing how deviations from modeled rates of predicted changes for an individual over time correlate with blood glucose levels in the hours before a MMTT. This may lead to refinement of future trial protocols to ensure tighter regulation of glycemic excursions ahead of provocative testing.

Type 1 Diabetes Prevention: a systematic review of studies testing disease-modifying therapies and features linked to treatment response.

Background: Type 1 diabetes (T1D) results from immune-mediated destruction of insulin-producing beta cells. Efforts to prevent T1D have focused on modulating immune responses and supporting beta cell health; however, heterogeneity in disease progression and responses to therapies have made these efforts difficult to translate to clinical practice, highlighting the need for precision medicine approaches to T1D prevention. Methods: To understand the current state of knowledge regarding precision approaches to T1D prevention, we performed a systematic review of randomized-controlled trials from the past 25 years testing disease-modifying therapies in T1D and/or identifying features linked to treatment response, analyzing bias using a Cochrane-risk-of-bias instrument. Results: We identified 75 manuscripts, 15 describing 11 prevention trials for individuals with increased risk for T1D, and 60 describing treatments aimed at preventing beta cell loss in individuals at disease onset. Seventeen agents tested, mostly immunotherapies, showed benefit compared to placebo (only two prior to T1D onset). Fifty-seven studies employed precision analyses to assess features linked to treatment response. Age, measures of beta cell function and immune phenotypes were most frequently tested. However, analyses were typically not prespecified, with inconsistent methods reporting, and tended to report positive findings. Conclusions: While the quality of prevention and intervention trials was overall high, low quality of precision analyses made it difficult to draw meaningful conclusions that inform clinical practice. Thus, prespecified precision analyses should be incorporated into the design of future studies and reported in full to facilitate precision medicine approaches to T1D prevention. Plain Language Summary: Type 1 diabetes (T1D) results from the destruction of insulin-producing cells in the pancreas, necessitating lifelong insulin dependence. T1D prevention remains an elusive goal, largely due to immense variability in disease progression. Agents tested to date in clinical trials work in a subset of individuals, highlighting the need for precision medicine approaches to prevention. We systematically reviewed clinical trials of disease-modifying therapy in T1D. While age, measures of beta cell function, and immune phenotypes were most commonly identified as factors that influenced treatment response, the overall quality of these studies was low. This review reveals an important need to proactively design clinical trials with well-defined analyses to ensure that results can be interpreted and applied to clinical practice.

Improved Glycemia with Hybrid Closed-Loop Versus Continuous Subcutaneous Insulin Infusion Therapy: Results from a Randomized Controlled Trial.

Objective: To evaluate safety and effectiveness of MiniMed™ 670G hybrid closed loop (HCL) in comparison with continuous subcutaneous insulin infusion (CSII) therapy for 6 months in persons with type 1 diabetes (T1D). Methods: Adults (aged 18-80 years), adolescents, and children (aged 2-17 years) with T1D who were using CSII therapy were enrolled and randomized (1:1) to 6 months of HCL intervention (n = 151, mean age of 39.9 ± 19.8 years) or CSII without continuous glucose monitoring (n = 151, 35.7 ± 18.4 years). Primary effectiveness endpoints included change in A1C for Group 1 (baseline A1C >8.0%), from baseline to the end of study, and difference in the end of study percentage of time spent below 70 mg/dL (%TBR <70 mg/dL) for Group 2 (baseline A1C ≤8.0%), to show superiority of HCL intervention versus control. Secondary effectiveness endpoints were change in A1C and %TBR <70 mg/dL for Group 2 and Group 1, respectively, to show noninferiority of HCL intervention versus control. Primary safety endpoints were rates of severe hypoglycemia and diabetic ketoacidosis (DKA). Results: Change in A1C and difference in %TBR <70 mg/dL for the overall group were significantly improved, in favor of HCL intervention. In addition, a significant mean (95% confidence interval) change in A1C was observed for both Group 1 (-0.8% [-1.1% to -0.4%], P < 0.0001) and Group 2 (-0.3% [-0.5% to -0.1%], P < 0.0001), in favor of HCL intervention. The same was observed for difference in %TBR <70 mg/dL for Group 1 (-2.2% [-3.6% to -0.9%]) and Group 2 (-4.9% [-6.3% to -3.6%]) (P < 0.0001 for both). There was one DKA event during run-in and six severe hypoglycemic events: two during run-in and four during study (HCL: n = 0 and CSII: n = 4 [6.08 per 100 patient-years]). Conclusions: This RCT demonstrates that the MiniMed 670G HCL safely and significantly improved A1C and %TBR <70 mg/dL compared with CSII control in persons with T1D, irrespective of baseline A1C level.

Screening for Type 1 Diabetes in the General Population: A Status Report and Perspective.

Most screening programs to identify individuals at risk for type 1 diabetes have targeted relatives of people living with the disease to improve yield and feasibility. However, ∼90% of those who develop type 1 diabetes do not have a family history. Recent successes in disease-modifying therapies to impact the course of early-stage disease have ignited the consideration of the need for and feasibility of population screening to identify those at increased risk. Existing population screening programs rely on genetic or autoantibody screening, and these have yielded significant information about disease progression and approaches for timing for screening in clinical practice. At the March 2021 Type 1 Diabetes TrialNet Steering Committee meeting, a session was held in which ongoing efforts for screening in the general population were discussed. This report reviews the background of these efforts and the details of those programs. Additionally, we present hurdles that need to be addressed for successful implementation of population screening and provide initial recommendations for individuals with positive screens so that standardized guidelines for monitoring and follow-up can be established.

IL-6 receptor blockade does not slow ß cell loss in new-onset type 1 diabetes.

BackgroundIL-6 receptor (IL-6R) signaling drives development of T cell populations important to type 1 diabetes pathogenesis. We evaluated whether blockade of IL-6R with monoclonal antibody tocilizumab would slow loss of residual ß cell function in newly diagnosed type 1 diabetes patients.MethodsWe conducted a multicenter, randomized, placebo-controlled, double-blind trial with tocilizumab in new-onset type 1 diabetes. Participants were screened within 100 days of diagnosis. Eligible participants were randomized 2:1 to receive 7 monthly doses of tocilizumab or placebo. The primary outcome was the change from screening in the mean AUC of C-peptide collected during the first 2 hours of a mixed meal tolerance test at week 52 in pediatric participants (ages 6-17 years).ResultsThere was no statistical difference in the primary outcome between tocilizumab and placebo. Immunophenotyping showed reductions in downstream signaling of the IL-6R in T cells but no changes in CD4 memory subsets, Th17 cells, Tregs, or CD4+ T effector cell resistance to Treg suppression. A DC subset decreased during therapy but regressed to baseline once therapy stopped. Tocilizumab was well tolerated.ConclusionTocilizumab reduced T cell IL-6R signaling but did not modulate CD4+ T cell phenotypes or slow loss of residual ß cell function in newly diagnosed individuals with type 1 diabetes.Trial RegistrationClinicalTrials.gov NCT02293837.FundingNIH National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) and National Institute of Allergy and Infectious Diseases (NIAID) UM1AI109565, UL1TR000004 from NIH/National Center for Research Resources (NCRR) Clinical and Translational Science Award (CTSA), NIH/NIDDK P30DK036836, NIH/NIDDK U01DK103266, NIH/NIDDK U01DK103266, 1UL1TR000064 from NIH/NCRR CTSA, NIH/National Center for Advancing Translational Sciences (NCATS) UL1TR001878, UL1TR002537 from NIH/CTSA; National Health and Medical Research Council Practitioner Fellowship (APP1136735), NIH/NIDDK U01-DK085476, NIH/CTSA UL1-TR002494, Indiana Clinical and Translational Science Institute Award UL1TR002529, Vanderbilt Institute for Clinical and Translational Research UL1TR000445. NIH/NCATS UL1TR003142, NIH/CTSA program UL1-TR002494, Veteran Affairs Administration, and 1R01AI132774.

Alefacept provides sustained clinical and immunological effects in new-onset type 1 diabetes patients.

BACKGROUND: Type 1 diabetes (T1D) results from destruction of pancreatic ß 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 ß 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 between-group 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.

Elimination of Pasteurella pneumotropica from a mouse barrier facility by using a modified enrofloxacin treatment regimen.

Multiple NOD. Cg-Prkdc(scid)Il2rg(tm1Wjl)Tg(HLA-A2.1)Enge/Sz (NSG/A2) transgenic mice maintained in a mouse barrier facility were submitted for necropsy to determine the cause of facial alopecia, tachypnea, dyspnea, and sudden death. Pneumonia and soft-tissue abscesses were observed, and Pasteurella pneumotropica biotype Jawetz was consistently isolated from the upper respiratory tract, lung, and abscesses. Epidemiologic investigation within the facility revealed presence of this pathogen in mice generated or rederived by the intramural Genetically Engineered Mouse Model (GEMM) Core but not in mice procured from several approved commercial vendors. Epidemiologic data suggested the infection originated from female or vasectomized male ND4 mice obtained from a commercial vendor and then comingled by the GEMM Core to induce pseudopregnancy in female mice for embryo implantation. Enrofloxacin delivered in drinking water (85 mg/kg body weight daily) for 14 d was sufficient to clear bacterial infection in normal, breeding, and immune-deficient mice without the need to change the antibiotic water source. This modified treatment regimen was administered to 2400 cages of mice to eradicate Pasteurella pneumotropica from the facility. Follow-up PCR testing for P. pneumotropica biotype Jawetz remained uniformly negative at 2, 6, 12, and 52 wk after treatment in multiple strains of mice that were originally infected. Together, these data indicate that enrofloxacin can eradicate P. pneumotropica from infected mice in a less labor-intensive approach that does not require breeding cessation and that is easily adaptable to the standard biweekly cage change schedule for individually ventilated cages.

Oral cysteamine bitartrate and N-acetylcysteine for patients with infantile neuronal ceroid lipofuscinosis: a pilot study.

BACKGROUND: Infantile neuronal ceroid lipofuscinosis is a devastating neurodegenerative lysosomal storage disease caused by mutations in the gene (CLN1 or PPT1) encoding palmitoyl-protein thioesterase-1 (PPT1). We have previously reported that phosphocysteamine and N-acetylcysteine mediate ceroid depletion in cultured cells from patients with this disease. We aimed to assess whether combination of oral cysteamine bitartrate and N-acetylcysteine is beneficial for patients with neuronal ceroid lipofuscinosis. METHODS: Children between 6 months and 3 years of age with infantile neuronal ceroid lipofuscinosis with any two of the seven most lethal PPT1 mutations were eligible for inclusion in this pilot study. All patients were recruited from physician referrals. Patients received oral cysteamine bitartrate (60 mg/kg per day) and N-acetylcysteine (60 mg/kg per day) and were assessed every 6-12 months until they had an isoelectric electroencephalogram (EEG, attesting to a vegetative state) or were too ill to travel. Patients were also assessed by electroretinography, brain MRI and magnetic resonance spectroscopy (MRS), and electron microscopic analyses of leukocytes for granular osmiophilic deposits (GRODs). Children also underwent physical and neurodevelopmental assessments on the Denver scale. Outcomes were compared with the reported natural history of infantile neuronal ceroid lipofuscinosis and that of affected older siblings. This trial is registered with ClinicalTrials.gov, number NCT00028262. FINDINGS: Between March 14, 2001, and June 30, 2012, we recruited ten children with infantile neuronal ceroid lipofuscinosis; one child was lost to follow-up after the first visit and nine patients (five girls and four boys) were followed up for 8 to 75 months. MRI showed abnormalities similar to those in previous reports; brain volume and N-acetyl aspartic acid (NAA) decreased steadily, but no published quantitative MRI or MRS studies were available for comparison. None of the children acquired new developmental skills, and their retinal function decreased progressively. Average time to isoelectric EEG (52 months, SD 13) was longer than reported previously (36 months). At the first follow-up visit, peripheral leukocytes in all nine patients showed virtually complete depletion of GRODs. Parents and physicians reported less irritability, improved alertness, or both in seven patients. No treatment-related adverse events occurred apart from mild gastrointestinal discomfort in two patients, which disappeared when liquid cysteamine bitartrate was replaced with capsules. INTERPRETATION: Our findings suggest that combination therapy with cysteamine bitartrate and N-acetylcysteine is associated with delay of isoelectric EEG, depletion of GRODs, and subjective benefits as reported by parents and physicians. Our systematic and quantitative report of the natural history of patients with infantile neuronal ceroid lipofuscinosis provides a guide for future assessment of experimental therapies. FUNDING: National Institutes of Health.

Combination therapy with sitagliptin and lansoprazole in patients with recent-onset type 1 diabetes (REPAIR-T1D): 12-month results of a multicentre, randomised, placebo-controlled, phase 2 trial.

BACKGROUND: Type 1 diabetes results from autoimmune destruction of pancreatic ß cells. Findings from preclinical studies suggest that dipeptidyl peptidase-4 inhibitors and proton-pump inhibitors might enhance ß-cell survival and regeneration. We postulated that sitagliptin and lansoprazole would preserve ß-cell function in patients with recent-onset type 1 diabetes. METHODS: We did a double-blind, placebo-controlled, phase 2 trial (REPAIR-T1D). Participants aged 11-36 years, diagnosed with type 1 diabetes within the past 6 months were recruited from Sanford Health Systems (Sioux Falls, SD, USA; Fargo, ND, USA), Children's Hospitals and Clinics of Minnesota (St Paul, MN, USA), and Rady Children's Hospital (San Diego, CA, USA). Participants were randomly assigned (2:1) to receive oral sitagliptin (100 mg for participants ≥18 years, 50 mg for those <18 years) and lansoprazole (60 mg for participants ≥18 years, 30 mg for those <18 years) or matched placebo for 12 months. Randomisation was done by a blocked randomisation process (blocks of three and six), with separate streams for younger (<18 years) and older (≥18 years) participants, and males and females. All participants and personnel remained masked until after the completion of the final 12 month visit, at which time data were unmasked to the analysis team. The primary endpoint was C-peptide response to a mixed meal challenge at 12 months measured as 2 h area under curve. Analysis was by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT01155284. FINDINGS: Between Sept 21, 2010, and May 29, 2012, 46 participants were randomly assigned to the treatment group and 22 to the placebo group; of whom 40 participants in the treatment group and 18 in the placebo group completed the 12-month treatment. At 12 months, the mean change in C-peptide area under curve was -229 pmol/L (95% CI -316 to -142) for the treatment group and -253 pmol/L (-383 to -123) for the placebo group; this difference was not significant (p=0·77). No adverse or serious adverse events were probably or definitely related to the study treatment. INTERPRETATION: Although the expected change in the primary endpoint was not achieved, not all participants had increases in glucagon-like peptide-1 and gastrin concentrations that were expected with treatment. Although participants did not have adverse events related to study drugs, the study is not powered to address safety definitively. Further trials including these drugs might be warranted, but should be designed to ensure appropriate selection of participants and increases in these intermediary hormones. FUNDING: Sanford Research and JDRF.

Targeting of memory T cells with alefacept in new-onset type 1 diabetes (T1DAL study): 12 month results of a randomised, double-blind, placebo-controlled phase 2 trial.

BACKGROUND: Type 1 diabetes results from autoimmune targeting of the pancreatic ß cells, likely mediated by effector memory T (Tem) cells. CD2, a T cell surface protein highly expressed on Tem cells, is targeted by the fusion protein alefacept, depleting Tem cells and central memory T (Tcm) cells. We postulated that alefacept would arrest autoimmunity and preserve residual ß cells in patients newly diagnosed with type 1 diabetes. METHODS: The T1DAL study is a phase 2, double-blind, placebo-controlled trial in patients with type 1 diabetes, aged 12-35 years who, within 100 days of diagnosis, were enrolled at 14 US sites. Patients were randomly assigned (2:1) to receive alefacept (two 12-week courses of 15 mg intramuscularly per week, separated by a 12-week pause) or a placebo. Randomisation was stratified by site, and was computer-generated with permuted blocks of three patients per block. All participants and site personnel were masked to treatment assignment. The primary endpoint was the change from baseline in mean 2 h C-peptide area under the curve (AUC) at 12 months. Secondary endpoints at 12 months were the change from baseline in the 4 h C-peptide AUC, insulin use, major hypoglycaemic events, and HbA1c concentrations. This trial is registered with ClinicalTrials.gov, number NCT00965458. FINDINGS: Of 73 patients assessed for eligibility, 33 were randomly assigned to receive alefacept and 16 to receive placebo. The mean 2 h C-peptide AUC at 12 months increased by 0.015 nmol/L (95% CI -0.080 to 0.110) in the alefacept group and decreased by 0.115 nmol/L (-0.278 to 0.047) in the placebo group, and the difference between groups was not significant (p=0.065). However, key secondary endpoints were met: the mean 4 h C-peptide AUC was significantly higher (mean increase of 0.015 nmol/L [95% CI -0.076 to 0.106] vs decrease of -0.156 nmol/L [-0.305 to -0.006]; p=0.019), and daily insulin use (0.48 units per kg per day for placebo vs 0.36 units per kg per day for alefacept; p=0.02) and the rate of hypoglycaemic events (mean of 10.9 events per person per year for alefacept vs 17.3 events for placebo; p<0.0001) was significantly lower at 12 months in the alefacept group than in the placebo group. Mean HbA1c concentrations at week 52 were not different between treatment groups (p=0.75). So far, no serious adverse events were reported and all patients had at least one adverse event. In the alefacept group, 29 (88%) participants had an adverse event related to study drug versus 15 (94%) participants in the placebo group. In the alefacept group, 14 (42%) participants had grade 3 or 4 adverse events compared with nine (56%) participants in the placebo group; no deaths occurred. INTERPRETATION: Although the primary outcome was not met, at 12 months, alefacept preserved the 4 h C-peptide AUC, lowered insulin use, and reduced hypoglycaemic events, suggesting efficacy. Safety and tolerability were similar in the alefacept and placebo groups. Alefacept could be useful to preserve ß-cell function in patients with new-onset type 1 diabetes.

Mouse Prkar1a haploinsufficiency leads to an increase in tumors in the Trp53+/- or Rb1+/- backgrounds and chemically induced skin papillomas by dysregulation of the cell cycle and Wnt signaling.

PRKAR1A inactivation leads to dysregulated cAMP signaling and Carney complex (CNC) in humans, a syndrome associated with skin, endocrine and other tumors. The CNC phenotype is not easily explained by the ubiquitous cAMP signaling defect; furthermore, Prkar1a(+/-) mice did not develop skin and other CNC tumors. To identify whether a Prkar1a defect is truly a generic but weak tumorigenic signal that depends on tissue-specific or other factors, we investigated Prkar1a(+/-) mice when bred within the Rb1(+/-) or Trp53(+/-) backgrounds, or treated with a two-step skin carcinogenesis protocol. Prkar1a(+/-) Trp53(+/-) mice developed more sarcomas than Trp53(+/-) mice (P < 0.05) and Prkar1a(+/-) Rb1(+/-) mice grew more (and larger) pituitary and thyroid tumors than Rb1(+/-) mice. All mice with double heterozygosity had significantly reduced life-spans compared with their single-heterozygous counterparts. Prkar1a(+/-) mice also developed more papillomas than wild-type animals. A whole-genome transcriptome profiling of tumors produced by all three models identified Wnt signaling as the main pathway activated by abnormal cAMP signaling, along with cell cycle abnormalities; all changes were confirmed by qRT-PCR array and immunohistochemistry. siRNA down-regulation of Ctnnb1, E2f1 or Cdk4 inhibited proliferation of human adrenal cells bearing a PRKAR1A-inactivating mutation and Prkar1a(+/-) mouse embryonic fibroblasts and arrested both cell lines at the G0/G1 phase of the cell cycle. In conclusion, Prkar1a haploinsufficiency is a relatively weak tumorigenic signal that can act synergistically with other tumor suppressor gene defects or chemicals to induce tumors, mostly through Wnt-signaling activation and cell cycle dysregulation, consistent with studies in human neoplasms carrying PRKAR1A defects.

The paradoxical increase in cortisol secretion induced by dexamethasone in primary pigmented nodular adrenocortical disease involves a glucocorticoid receptor-mediated effect of dexamethasone on protein kinase A catalytic subunits.

CONTEXT: Primary pigmented nodular adrenocortical disease (PPNAD) results in most cases from mutations of the protein kinase A (PKA) regulatory subunit 1A (PRKAR1A) gene. Patients with PPNAD exhibit a paradoxical increase in cortisol secretion in response to dexamethasone. OBJECTIVE: The aim was to investigate the mechanism of the action of dexamethasone on adrenocortical cells removed from patients with PPNAD and a transgenic model of PPNAD [Tg(tTA/X2AS) mice]. DESIGN AND SETTING: We performed an in vitro study in an academic research laboratory. PATIENTS: Eleven patients with histologically proven PPNAD were included in the study. INTERVENTION: Cultured PPNAD cells were incubated with dexamethasone in the presence of various modulators of the cAMP/PKA pathway and the glucocorticoid receptor antagonist RU486. MAIN OUTCOME MEASURE: Cortisol and corticosterone were measured by radioimmunological assays in cell culture supernatants. RESULTS: Dexamethasone stimulated in vitro cortisol secretion from PPNAD tissues in six patients. The stimulatory effect of dexamethasone on cortisol release was not reduced by the adenylyl cyclase inhibitor SQ22536 or potentiated by the phosphodiesterase inhibitor IMBX and the cAMP analog 8Br-cAMP. Conversely, the PKA inhibitor H89 and RU486 inhibited the cortisol response to dexamethasone. Dexamethasone had no effect on cortisol production from normal human adrenocortical cells but stimulated corticosteroidogenesis in the presence of RU486. Similarly, dexamethasone failed to influence corticosterone release by adrenocortical cells removed from Tg(tTA/X2AS) mice but stimulated corticosteroidogenesis in the presence of RU 486. CONCLUSIONS: These results indicate that, in human PPNAD tissues, dexamethasone paradoxically stimulates cortisol release through a glucocorticoid receptor-mediated effect on PKA catalytic subunits.

A genome-wide scan identifies mutations in the gene encoding phosphodiesterase 11A4 (PDE11A) in individuals with adrenocortical hyperplasia.

Phosphodiesterases (PDEs) regulate cyclic nucleotide levels. Increased cyclic AMP (cAMP) signaling has been associated with PRKAR1A or GNAS mutations and leads to adrenocortical tumors and Cushing syndrome. We investigated the genetic source of Cushing syndrome in individuals with adrenocortical hyperplasia that was not caused by known defects. We performed genome-wide SNP genotyping, including the adrenocortical tumor DNA. The region with the highest probability to harbor a susceptibility gene by loss of heterozygosity (LOH) and other analyses was 2q31-2q35. We identified mutations disrupting the expression of the PDE11A isoform-4 gene (PDE11A) in three kindreds. Tumor tissues showed 2q31-2q35 LOH, decreased protein expression and high cyclic nucleotide levels and cAMP-responsive element binding protein (CREB) phosphorylation. PDE11A codes for a dual-specificity PDE that is expressed in adrenal cortex and is partially inhibited by tadalafil and other PDE inhibitors; its germline inactivation is associated with adrenocortical hyperplasia, suggesting another means by which dysregulation of cAMP signaling causes endocrine tumors.

Detection of adrenocorticotropin-secreting pituitary adenomas by magnetic resonance imaging in children and adolescents with cushing disease.

CONTEXT: We recently showed that pre- and postcontrast spoiled gradient-recalled acquisition in the steady-state (SPGR) was superior to conventional pre- and postcontrast T-1 weighted spin echo (SE) acquisition magnetic resonance imaging (MRI) for the diagnostic evaluation of pituitary tumors in adult patients. OBJECTIVE: The present investigation assessed the use of SPGR vs. SE-MRI in the diagnostic evaluation of ACTH-secreting tumors in children and adolescents with Cushing disease. DESIGN: Data were analyzed retrospectively from a series of patients seen over 7 yr (1997-2004). SETTING: The setting for this study was a tertiary care referral center. PATIENTS: Thirty children with Cushing disease (13 females and 17 males with a mean age of 12 +/- 3 yr) were studied. INTERVENTIONS AND OUTCOME MEASURES: Imaging results were compared with surgical and pathological findings and the clinical outcome. RESULTS: Twenty-eight patients had microadenomas, and two had macroadenomas; the latter were identified by both MRI techniques. Precontrast SE and SPGR-MRI identified four and six of the microadenomas, respectively. Postcontrast SPGR-MRI identified the location of the tumor in 18 of 28 patients, whereas postcontrast SE-MRI identified the location and accurately estimated the size of the tumor in only five patients (P < 0.001). CONCLUSIONS: We conclude that conventional MRI, even with contrast enhancement, mostly failed to identify ACTH-secreting microadenomas in children and adolescents with Cushing disease. Postcontrast SPGR-MRI was superior to SE-MRI and should be used in addition to conventional SE-MRI in the pituitary evaluation of children and adolescents with suspected Cushing disease.

Down-regulation of regulatory subunit type 1A of protein kinase A leads to endocrine and other tumors.

Mutations of the human type Ialpha regulatory subunit (RIalpha) of cyclic AMP-dependent protein kinase (PKA; PRKAR1A) lead to altered kinase activity, primary pigmented nodular adrenocortical disease, and tumors of the thyroid and other tissues. To bypass the early embryonic lethality of Prkar1a(-/-) mice, we established transgenic mice carrying an antisense transgene for Prkar1a exon 2 (X2AS) under the control of a tetracycline-responsive promoter. Down-regulation of Prkar1a by up to 70% was achieved in transgenic mouse tissues and embryonic fibroblasts, with concomitant changes in kinase activity and increased cell proliferation, respectively. Mice developed thyroid follicular hyperplasia and adenomas, adrenocortical hyperplasia, and other features reminiscent of primary pigmented nodular adrenocortical disease, histiocytic and epithelial hyperplasias, lymphomas, and other mesenchymal tumors. These were associated with allelic losses of the mouse chromosome 11 Prkar1a locus, an increase in total type II PKA activity, and higher RIIbeta protein levels. This mouse provides a novel, useful tool for the investigation of cyclic AMP, RIalpha, and PKA functions and confirms the critical role of Prkar1a in tumorigenesis in endocrine and other tissues.

A mouse model for Carney complex.

Mice with complete inactivation of the type Ialpha regulatory subunit (RIalpha) of cyclic (c) AMP-dependent protein kinase (PKA) (coded by the Prkar1a gene) die early in embryonic life. To bypass the early embryonic lethality of Prkar1a-/- mice, we established transgenic mice carrying an antisense transgene for Prkar1a exon 2 (X2AS) under the control of a tetracycline-responsive promoter. Mice developed thyroid follicular hyperplasia and adenomas, adrenocortical hyperplasia, and other features reminiscent of PPNAD, and histiocytic and epithelial hyperplasias, lymphomas, and other mesenchymal tumors. This mouse provides a useful tool for the investigation of cAMP, RIalpha, and PKA functions and confirms Prkar1a's critical role in tumorigenesis in endocrine and other tissues.