Long-term weight gain in children with craniopharyngioma.

OBJECTIVE: Adamantinomatous craniopharyngioma mainly affects children. Excessive weight gain is a major long-term complication. The primary objective of this study was to assess long-term weight changes in children treated for craniopharyngioma. The secondary objectives were to identify risk factors for excessive weight gain and to look for associations with hypothalamic damage by the tumour or treatment. DESIGN: Single-centre retrospective cohort study. METHOD: Children managed for craniopharyngioma at our centre between 1990 and 2019 were included. The body mass index (BMI) standard deviation scores (SDS) at baseline and at last follow-up were compared. Univariate and multivariate analyses were performed in order to identify variables associated with the long-term BMI-SDS variation. RESULTS: The 108 patients had a mean follow-up of 10.4 years. The mean BMI-SDS increase over time was 2.11 (P < .001) overall, 1.21 (P < .001) in the group without hypothalamic involvement by the tumour, and 1.95 (P < .001) in the group managed using intended hypothalamus-sparing surgery. The absence of hypothalamic involvement by the tumour or treatment was significantly associated with less weight gain (P = .046 and P < .01, respectively). After adjustment, factors associated with a BMI-SDS change greater than 2 were female sex (P = .023), tumour involving the hypothalamus (P = .04), and higher baseline BMI (P < .001). CONCLUSION: Clinically significant weight gain occurred in nearly all children treated for craniopharyngioma, including those whose hypothalamus was spared by the tumour and intentionally by treatment. However, hypothalamus integrity was associated with less weight gain. Despite hypothalamus-sparing strategies, hypothalamic obesity remains a major concern, indicating a need for novel treatment approaches.

Identifying patient-related predictors of permanent growth hormone deficiency.

Objective: Isolated childhood growth hormone deficiency (GHD) can persist into adulthood, and re-testing at the transition period is needed to determine whether continued growth hormone therapy is indicated. Here, our objective was to identify predictors of permanent GHD. Design: Retrospective single-centre study of patients with childhood-onset GHD who were re-tested after adult height attainment. Methods: Auxological, clinical, laboratory, and MRI data throughout follow-up were collected. Results: We included 101 patients. At GH treatment initiation, age was 8.1 ± 0.4 years, height -2.25 ± 0.8, and BMI -0.27 ± 0.1 SDS. The 29 (28.7%) patients with persistent GHD had lower height SDS (-2.57 ± 0.1 vs. -2.11 ± 0.1, p<0.001) and mean GH peaks (8.4 ± 1.0 vs.13.2 ± 0.5 mIU/L, p<0.001) at GHD diagnosis; at adult height, they had lower IGF1 (232 ± 19.9 vs. 331 ± 9.1 ng/mL, p<0.001) and higher BMI SDS (-0.15 ± 0.27 vs. -0.73 ± 0.13, p<0.005). By multivariate analysis, the best predictive model included height and BMI SDS, both GH peaks, and MRI findings at diagnosis. Patients with height at diagnosis <-3 SDS had a 7.7 (95% IC 1.4-43.1, p=0.02) fold higher risk of persistent GHD after adjustment on BMI SDS. An abnormal pituitary region by MRI was the strongest single predictor (7.2 times, 95% CI 2.7-19.8) and after multivariate analysis adjustment for GH peaks and height SDS at diagnosis, the risk increased to 10.6 (1.8 - 61.3) times. Conclusions: Height <-3 SDS at GHD diagnosis and pituitary MRI abnormalities should lead to a high index of suspicion for persistent GHD.

GH and Childhood-onset Craniopharyngioma: When to Initiate GH Replacement Therapy?

CONTEXT: Craniopharyngioma is a benign brain tumor with frequent local recurrence or progression after treatment. GH replacement therapy (GHRT) is prescribed in children with GH deficiency resulting from childhood-onset craniopharyngioma. OBJECTIVE: To evaluate whether a shorter delay of GHRT initiation after childhood-onset craniopharyngioma completion therapy increased the risk of a new event (progression or recurrence). METHODS: Retrospective, observational, monocenter study. We compared a cohort of 71 childhood-onset patients with craniopharyngiomas treated with recombinant human GH (rhGH). Twenty-seven patients were treated with rhGH at least 12 months after craniopharyngioma treatment (>12-month group) and 44 patients before 12 months (<12-month group), among which 29 patients were treated between 6 and 12 months (6-12 month group). The main outcome was the risk of tumor new event (progression of residual tumor or tumor recurrence after complete resection) after primary treatment in the >12-month group and in the <12 month or in the 6- to 12-month group patients. RESULTS: In the >12-month group, the 2- and 5-year event-free survivals were respectively 81.5% (95% CI, 61.1-91.9) and 69.4% (95% CI, 47.9-83.4) compared with 72.2% (95% CI, 56.3-83.1) and 69.8% (95% CI, 53.8-81.2) in the <12-month group. The 2- and 5-year event-free survivals were the same in the 6- to 12-month group (72.4%; 95% CI, 52.4-85.1). By log-rank test, the event-free survival was not different between groups (P = .98 and P = .91).The median time for event was not statistically different.In univariate and multivariate analysis, the risk of craniopharyngioma new event was not associated with the GHRT time delay after craniopharyngioma treatment. CONCLUSIONS: No association was found between GHRT time delay after childhood-onset craniopharyngioma treatment and an increased risk of recurrence or tumor progression, suggesting GH replacement therapy can be initiated 6 months after last treatment for craniopharyngiomas.

PIK3CA gain-of-function mutation in adipose tissue induces metabolic reprogramming with Warburg-like effect and severe endocrine disruption.

PIK3CA-related overgrowth syndrome (PROS) is a genetic disorder caused by somatic mosaic gain-of-function mutations of PIK3CA. Clinical presentation of patients is diverse and associated with endocrine disruption. Adipose tissue is frequently involved, but its role in disease development and progression has not been elucidated. Here, we created a mouse model of PIK3CA-related adipose tissue overgrowth that recapitulates patient phenotype. We demonstrate that PIK3CA mutation leads to GLUT4 membrane accumulation with a negative feedback loop on insulin secretion, a burst of liver IGFBP1 synthesis with IGF-1 sequestration, and low circulating levels. Mouse phenotype was mainly driven through AKT2. We also observed that PIK3CA mutation induces metabolic reprogramming with Warburg-like effect and protein and lipid synthesis, hallmarks of cancer cells, in vitro, in vivo, and in patients. We lastly show that alpelisib is efficient at preventing and improving PIK3CA-adipose tissue overgrowth and reversing metabolomic anomalies in both animal models and patients.

Mitchell-Riley Syndrome: Improving Clinical Outcomes and Searching for Functional Impact of RFX-6 Mutations.

Aims/Hypothesis: Caused by biallelic mutations of the gene encoding the transcription factor RFX6, the rare Mitchell-Riley syndrome (MRS) comprises neonatal diabetes, pancreatic hypoplasia, gallbladder agenesis or hypoplasia, duodenal atresia, and severe chronic diarrhea. So far, sixteen cases have been reported, all with a poor prognosis. This study discusses the multidisciplinary intensive clinical management of 4 new cases of MRS that survived over the first 2 years of life. Moreover, it demonstrates how the mutations impair the RFX6 function. Methods: Clinical records were analyzed and described in detail. The functional impact of two RFX6R181W and RFX6V506G variants was assessed by measuring their ability to transactivate insulin transcription and genes that encode the L-type calcium channels required for normal pancreatic beta-cell function. Results: All four patients were small for gestational age (SGA) and prenatally diagnosed with duodenal atresia. They presented with neonatal diabetes early in life and were treated with intravenous insulin therapy before switching to subcutaneous insulin pump therapy. All patients faced recurrent hypoglycemic episodes, exacerbated when parenteral nutrition (PN) was disconnected. A sensor-augmented insulin pump therapy with a predictive low-glucose suspension system was installed with good results. One patient had a homozygous c.1517T>G (p.Val506Gly) mutation, two patients had a homozygous p.Arg181Trp mutation, and one patient presented with new compound heterozygosity. The RFX6V506G and RFX6R181W mutations failed to transactivate the expression of insulin and genes that encode L-type calcium channel subunits required for normal pancreatic beta-cell function. Conclusions/Interpretation: Multidisciplinary and intensive disease management improved the clinical outcomes in four patients with MRS, including adjustment of parenteral/oral nutrition progression and advanced diabetes technologies. A better understanding of RFX6 function, in both intestine and pancreas cells, may break ground in new therapies, particularly regarding the use of drugs that modulate the enteroendocrine system.

Graves' disease and pregnancy.

This section deals with the specificities of managing Graves' disease during pregnancy. Graves' disease incurs risks of fetal, neonatal and maternal complications that are rare but may be severe: fetal hyper- or hypothyroidism, usually first showing as fetal goiter, neonatal dysthyroidism, premature birth and pre-eclampsia. Treatment during pregnancy is based on antithyroid drugs alone, without association to levothyroxine. An history of Graves' disease, whether treated radically or not, with persistent maternal anti-TSH-receptor antibodies must be well identified. Fetal monitoring should be initiated in a multidisciplinary framework that should be continued throughout pregnancy. Neonatal monitoring is also crucial if the mother still shows anti-TSH-receptor antibodies at end of pregnancy or underwent antithyroid treatment. The risk of recurrence of hyperthyroidism in the weeks following delivery requires maternal monitoring. The long-term neuropsychological progression of children of mothers with Graves' disease is poorly known.

A selective CD28 antagonist and rapamycin synergise to protect against spontaneous autoimmune diabetes in NOD mice.

AIMS/HYPOTHESIS: The CD28/B7 interaction is critical for both effector T cell activation and forkhead box P3 (FOXP3)+ regulatory T cell (Treg) generation and homeostasis, which complicates the therapeutic use of cytotoxic T lymphocyte-associated antigen 4 (CTLA-4)-immunoglobulin fusion protein (CTLA-4Ig) in autoimmunity. Here, we evaluated the impact of a simultaneous and selective blockade of the CD28 and mammalian target of rapamycin (mTOR) pathways in the NOD mouse model of type 1 diabetes. METHODS: NOD mice were treated with PEGylated anti-CD28 Fab' antibody fragments (PV1-polyethylene glycol [PEG], 10 mg/kg i.p., twice weekly), rapamycin (1 mg/kg i.p., twice weekly) or a combination of both drugs. Diabetes incidence, pancreatic islet infiltration and autoreactive T cell responses were analysed. RESULTS: We report that 4 week administration of PV1-PEG combined with rapamycin effectively controlled the progression of autoimmune diabetes in NOD mice at 10 weeks of age by reducing T cell activation and migration into the pancreas. Treatment with rapamycin alone was without effect, as was PV1-PEG monotherapy initiated at 4, 6 or 10 weeks of age. Prolonged PV1-PEG administration (for 10 weeks) accelerated diabetes development associated with impaired peripheral Treg homeostasis. This effect was not observed with the combined treatment. CONCLUSIONS/INTERPRETATION: CD28 antagonist and rapamycin treatment act in a complementary manner to limit T cell activation and infiltration of pancreatic islets and diabetes development. These data provide new perspectives for the treatment of autoimmune diabetes and support the therapeutic potential of protocols combining antagonists of CD28 (presently in clinical development) and the mTOR pathway.

Differential Impact of T-bet and IFNγ on Pancreatic Islet Allograft Rejection.

BACKGROUND: T cell-mediated graft rejection is mostly correlated with potent Th1 responses. However, because IFNγ mice reject their graft as efficiently as wild-type (WT) mice, the exact contribution of IFNγ and its transcription factor T-bet remains a matter of debate. Here, we address this question in the context of pancreatic islet allograft to better inform the molecular pathways that hampers islet survival in vivo. METHODS: Pancreatic islets from BALB/c mice were transplanted in WT, IFNγ, or T-bet C57BL/6 mice. Graft survival and the induction of effector and cytotoxic T-cell responses were monitored. RESULTS: Rejection of fully mismatched islet allografts correlated with high expression of both IFNγ and T-bet in WT recipients. However, allogeneic islets were permanently accepted in T-bet mice, in contrast to IFNγ hosts. Long-term survival correlated with decreased CD4 and CD8 T-cell infiltrates, drastically reduced donor-specific IFNγ and tumor necrosis factor tumor necrosis factor α responses and very low expression of the cytotoxic markers granzyme B, perforin, and FasLigand. In addition, in vitro and in vivo data pointed to an increased susceptibility of T-bet CD8 T cell to apoptosis. These observations were not reported in IFNγ mice, which have set up compensatory effector mechanisms comprising an increased expression of the transcription factor Eomes and cytolytic molecules as well as tumor necrosis factor α-mediated but not IL-4 nor IL-17-mediated allogeneic responses. CONCLUSIONS: Anti-islet T-cell responses require T-bet but not IFNγ-dependent programs. Our results provide new clues on the mechanisms dictating islet rejection and may help refine the therapeutic/immunosuppressive regimens applied in diabetic patients receiving islets or pancreas allografts.

Oral histone deacetylase inhibitor synergises with T cell targeted immunotherapy to preserve beta cell metabolic function and induce stable remission of new-onset autoimmune diabetes in NOD mice.

AIM/HYPOTHESIS: Combination therapy targeting the major actors involved in the immune-mediated destruction of pancreatic beta cells appears to be an indispensable approach to treat type 1 diabetes effectively. We hypothesised that the combination of an orally active pan-histone deacetylase inhibitor (HDACi: givinostat) with subtherapeutic doses of CD3 antibodies may provide ideal synergy to treat ongoing autoimmunity. METHODS: NOD mice transgenic for the human CD3ε (also known as CD3E) chain (NOD-huCD3ε) were treated for recent-onset diabetes with oral givinostat, subtherapeutic doses of humanised CD3 antibodies (otelixizumab, 50 µg/day, 5 days, i.v.) or a combination of both drugs. Disease remission, metabolic profiles and autoreactive T cell responses were analysed in treated mice. RESULTS: We demonstrated that givinostat synergised with otelixizumab to induce durable remission of diabetes in 80% of recently diabetic NOD-huCD3ε mice. Remission was obtained in only 47% of mice treated with otelixizumab alone. Oral givinostat monotherapy did not reverse established diabetes but reduced the in situ production of inflammatory cytokines (IL-1ß, IL-6, TNF-α). Importantly, the otelixizumab + givinostat combination strongly improved the metabolic status of NOD-huCD3ε mice; the mice recovered the capacity to appropriately produce insulin, control hyperglycaemia and sustain glucose tolerance. Finally, diabetes remission induced by the combination therapy was associated with a significant reduction of insulitis and autoantigen-specific CD8+ T cell responses. CONCLUSIONS/INTERPRETATION: HDACi and low-dose CD3 antibodies synergised to abrogate in situ inflammation and thereby improved pancreatic beta cell survival and metabolic function leading to long-lasting diabetes remission. These results support the therapeutic potential of protocols combining these two drugs, both in clinical development, to restore self-tolerance and insulin independence in type 1 diabetes.

The Induction and Maintenance of Transplant Tolerance Engages Both Regulatory and Anergic CD4+ T cells.

Therapeutic tolerance to self-antigens or foreign antigens is thought to depend on constant vigilance by Foxp3+ regulatory T cells (Tregs). Previous work using a pancreatic islet allograft model and a short pulse of CD3 antibody therapy has shown that CD8+ T cells become anergic and use TGFß and coinhibitory signaling as their contribution to the tolerance process. Here, we examine the role of CD4+ T cells in tolerization by CD3 antibodies. We show that both Foxp3+ Tregs and CD4+ T cell anergy play a role in the induction of tolerance and its maintenance. Foxp3+ Tregs resisted CD3 antibody-mediated depletion, unlike intragraft Th1 CD4+ lymphocytes coexpressing granzyme B and Tbx21, which were selectively eliminated. Tregs were mandatory for induction of tolerance as their depletion at the time of CD3 antibody therapy or for a short time thereafter, by an antibody to CD25 (PC61), led to graft rejection. Early treatment with CTLA-4 antibody gave the same outcome. In contrast, neither PC61 nor anti-CTLA-4 given late, at day 100 posttransplant, reversed tolerance once established. Ablation of Foxp3 T cells after diphtheria toxin injection in tolerant Foxp3DTR recipient mice provided the same outcome. Alloreactive T cells had been rendered intrinsically unresponsive as total CD4+ or Treg-deprived CD4+ T cells from tolerant recipients were unable to mount donor-specific IFN-γ responses. In addition, intragraft Treg-deprived CD4+ T cells lacked proliferative capacities, expressed high levels of the inhibitory receptor PD-1, and exhibited a CD73hiFR4hi phenotype, thus reflecting a state of T cell anergy. We conclude that Tregs play a substantive and critical role in guiding the immune system toward tolerance of the allograft, when induced by CD3 antibody, but are less important for maintenance of the tolerant state, where T cell anergy appears sufficient.

Revisiting autoimmune gastritis in children and adolescents with type 1 diabetes.

OBJECTIVE: Assess the frequency of anti-H+ /K+ adenosine triphosphatase (ATPase) autoantibodies (AAB) and symptoms of autoimmune gastritis in children and adolescents with type 1 diabetes (T1D). RESEARCH DESIGN AND METHODS: Anti-H+ /K+ ATPase AAB were measured in 402 children and adolescents (210 boys and 192 girls, 11.1 ± 4.5 years) treated for T1D (screened positive for ß-cell AAB), along with search of symptoms of anemia (hemoglobin, serum iron, and ferritin levels) and gastric pain. The AAB specific for thyroperoxydase, thyroglobulin, and transglutaminase were also measured. RESULTS: Anti-H+ /K+ ATPase AAB were present in 6.5% of children. Their frequency increased with age: 4% at 10 years, 10% at 15 years, and 20% at 20 years. Iron deficiency (45% vs 3.8%), iron deficiency anemia (36% vs 3.8%), antithyroid AAB (24% vs 9.7%), and family history of Graves' disease (25% vs 5.6%) were more frequent in patients with anti-H+ /K+ ATPase AAB. Two patients, a 13-year-old girl and a 11-year-old boy, experienced symptoms (iron deficiency anemia and epigastric pain) which led to diagnosis of autoimmune gastritis confirmed upon fibroscopy. Both showed high levels of anti-H+ /K+ ATPase AAB and atrophic gastritis. CONCLUSIONS: Autoimmune gastritis presents an age-dependent frequency in children and adolescents with T1D but is rarely symptomatic. Screening for anti-H+ /K+ ATPase AAB should thus target patients with iron deficiency, anemia, epigastralgia, autoimmune thyroiditis, or age over 15 years.

Regulatory mechanisms of immune tolerance in type 1 diabetes and their failures.

In this brief review we propose to discuss salient data showing the importance of immune regulatory mechanisms, and in particular of Treg, for the control of pathogenic anti-ß-cell response in autoimmune diabetes. Disease progression that culminates with the massive destruction of insulin-secreting ß-cells and advent of hyperglycemia and glycosuria tightly correlates with a functional deficit in immune regulation. Better dissection of the cellular and molecular mechanisms through which the immune system normally sustains tolerance to "self", and which become defective when autoimmune aggression is overt, is the only direct and robust way to learn how to harness these effectively, so as to restore immune tolerance in patients with insulin-dependent type 1 diabetes. No doubt that regulatory T cells are a privileged mechanism underlying this self-tolerance in the periphery. The discovery of the key role of the transcription factor FoxP3, represented the cornerstone leading to the great advances in the field we are witnessing today. Type 1 diabetes is certainly one of the prototypic T cell-mediated autoimmune diseases where immune regulatory mechanisms relying on specialized subsets of T cells have been the most thoroughly analyzed from the fundamental point of view and also largely exploited in a translational therapeutic perspective.

TGFß-dependent expression of PD-1 and PD-L1 controls CD8(+) T cell anergy in transplant tolerance.

CD8(+) T cell anergy is a critical mechanism of peripheral tolerance, poorly investigated in response to immunotherapy. Here, using a pancreatic islet allograft model and CD3 antibody therapy, we showed, by single cell gene profiling, that intragraft CD8(+) lymphocytes coexpressing granzyme B and perforin were selectively depleted through the Fas/FasL pathway. This step led to long-standing anergy of the remaining CD8(+) T cells marked by the absence of cytotoxic/inflammatory gene expression also confirmed by transcriptome analysis. This sustained unresponsiveness required the presence of the alloantigens. Furthermore, tissue-resident CD8(+) lymphocytes produced TGFß and expressed the inhibitory receptors PD-1 and PD-L1. Blockade of TGFß downregulated PD-1 and PD-L1 expression and precipitated graft rejection. Neutralizing PD-1, PD-L1 or TGFßRII signaling in T cells also abrogated CD3 antibody-induced tolerance. These studies unravel novel mechanisms underlying CD8(+) T cell anergy and reveal a cell intrinsic regulatory link between the TGFß and the PD-1/PD-L1 pathways.

Combining autologous dendritic cell therapy with CD3 antibodies promotes regulatory T cells and permanent islet allograft acceptance.

Cell therapy and the use of mAbs that interfere with T cell effector functions constitute promising approaches for the control of allograft rejection. In the current study, we investigated a novel approach combining administration of autologous tolerogenic dendritic cells with short-term treatment with CD3-specific Abs. Permanent acceptance of pancreatic islet allografts was achieved in mice treated with the combination therapy the day before transplantation but not in recipients treated with either therapy alone. The combination treatment induced a marked decrease in T cells infiltrating the allografts and a sustained reduction of antidonor responses. Importantly, CD4(+)Foxp3(+) regulatory T cells appeared to play a crucial role in the long-term graft acceptance. Their frequency increased significantly in the spleen, draining lymph nodes, and transplanted islets and remained elevated over the long term; they exhibited increased donor-specific suppressive functions; and their removal at the time of transplantation abrogated the therapeutic effect of the combined therapy. These results support the therapeutic potential of protocols combining autologous dendritic cells and low-dose CD3 Abs, both currently in clinical development, and that act in synergy to control allogeneic immune responses and favor graft survival in a full-mismatch situation.

Management of neonates born to women with Graves' disease: a cohort study.

OBJECTIVE: Hyperthyroidism in neonates born to mothers with Graves' disease (GD) can be associated with significant morbidity and mortality, but is still overlooked by clinicians. Management of neonatal hyperthyroidism would be improved by a better understanding of the predictive factors involved. The aim of this study was to evaluate the course of thyroid function and clinical outcomes during the first postnatal month in babies born to mothers with GD. DESIGN: Prospective observational study. METHODS: Sixty-eight neonates born to mothers with GD were managed from birth and divided into three groups based on thyrotropin receptor antibody (TRAb) and anti-thyroid drug (ATD) status in the mother: TRAb(-ve)/ATD(-ve), n=27; TRAb(-ve)/ATD(+) (ve), n=8; and TRAb(+ve)/ATD(+ve), n=33. The main outcome measures were clinical examination, thyroid function tests (TSH, free thyroxine (FT4), free triiodothyronine, and TRAb), echocardiography, thyroid ultrasonography, and bone maturation assessment. RESULTS: None of the infants born to TRAb(-ve) mothers with GD developed neonatal hyperthyroidism. Of the 33 TRAb(+ve)/ATD(+ve) neonates, 24 (72.7%) had positive TRAb on cord blood assays, and seven of these developed neonatal hyperthyroidism. FT4 elevation between days 3 and 7 but not at birth was predictive of the development of hyperthyroidism. CONCLUSIONS: TRAb status should be checked in the third trimester in mothers with GD and on cord blood in their neonates; if positive, it indicates a high risk of neonatal hyperthyroidism. FT4 measurement at birth should be repeated between days 3 and 5 (and by day 7 at the latest); rapid FT4 elevation during the first postnatal week is predictive of hyperthyroidism and warrants ATD therapy.