First phase insulin release and glucose tolerance in children with Fanconi anemia after hematopoietic cell transplantation

Longitudinal clinical manifestations of Fanconi anemia: A systematized review

Fanconi anemia (FA) is a rare and complex inherited genetic disorder characterized by impaired DNA repair mechanisms leading to genomic instability. Individuals with FA have increased susceptibility to congenital anomalies, progressive bone marrow failure, leukemia and malignant tumors, endocrinopathies and other medical issues. In recent decades, steadily improved approaches to hematopoietic cell transplantation (HCT), the only proven curative therapy for the hematologic manifestations of FA, have significantly increased the life expectancy of affected individuals, illuminating the need to understand the long-term consequences and multi-organ ramifications. Utilizing a systematized review approach with narrative synthesis of each primary issue and organ system, we shed light on the challenges and opportunities for optimizing the care and quality of life for individuals with FA and identify knowledge gaps informing future research directions.

Delineating the role of FANCA in glucose-stimulated insulin secretion in β cells through its protein interactome

Hyperinsulinemia affects 72% of Fanconi anemia (FA) patients and an additional 25% experience lowered glucose tolerance or frank diabetes. The underlying molecular mechanisms contributing to the dysfunction of FA pancreas β cells is unknown. Therefore, we sought to evaluate the functional role of FANCA, the most commonly mutated gene in FA, in glucose-stimulated insulin secretion (GSIS). This study reveals that FANCA or FANCB knockdown impairs GSIS in human pancreas β cell line EndoC-βH3. To identify potential pathways by which FANCA might regulate GSIS, we employed a proteomics approach to identify FANCA protein interactions in EndoC-βH3 differentially regulated in response to elevated glucose levels. Glucose-dependent changes in the FANCA interaction network were observed, including increased association with other FA family proteins, suggesting an activation of the DNA damage response in response to elevated glucose levels. Reactive oxygen species increase in response to glucose stimulation and are necessary for GSIS in EndoC-βH3 cells. Glucose-induced activation of the DNA damage response was also observed as an increase in the DNA damage foci marker γ-H2AX and dependent upon the presence of reactive oxygen species. These results illuminate the role of FANCA in GSIS and its protein interactions regulated by glucose stimulation that may explain the prevalence of β cell-specific endocrinopathies in FA patients.

dUTPase (DUT) Is Mutated in a Novel Monogenic Syndrome With Diabetes and Bone Marrow Failure

We describe a new syndrome characterized by early-onset diabetes associated with bone marrow failure, affecting mostly the erythrocytic lineage. Using whole-exome sequencing in a remotely consanguineous patient from a family with two affected siblings, we identified a single homozygous missense mutation (chr15.hg19:g.48,626,619A>G) located in the dUTPase (DUT) gene (National Center for Biotechnology Information Gene ID 1854), affecting both the mitochondrial (DUT-M p.Y142C) and the nuclear (DUT-N p.Y54C) isoforms. We found the same homozygous mutation in an unrelated consanguineous patient with diabetes and bone marrow aplasia from a family with two affected siblings, whereas none of the >60,000 subjects from the Exome Aggregation Consortium (ExAC) was homozygous for this mutation. This replicated observation probability was highly significant, thus confirming the role of this DUT mutation in this syndrome. DUT is a key enzyme for maintaining DNA integrity by preventing misincorporation of uracil into DNA, which results in DNA toxicity and cell death. We showed that DUT silencing in human and rat pancreatic β-cells results in apoptosis via the intrinsic cell death pathway. Our findings support the importance of tight control of DNA metabolism for β-cell integrity and warrant close metabolic monitoring of patients treated by drugs affecting dUTP balance.

Endocrinopathies, Bone Health, and Insulin Resistance in Patients with Fanconi Anemia after Hematopoietic Cell Transplantation

A number of endocrinopathies have been described after hematopoietic cell transplantation (HCT), but data are limited in patients with Fanconi anemia (FA). We report several endocrine-based disorders in a cohort of 44 patients with FA after HCT compared with both 74 patients who received HCT for hematologic malignancies and with 275 healthy controls. Endocrinopathies assessed included hypothyroidism, hypogonadism, short stature, dyslipidemia, insulin resistance, abnormalities in body composition, and bone health. Most (86%) patients with FA had at least 1 endocrinopathy, with 11% having 3 or more. Hypothyroidism was seen in 57%, hypogonadism in 27%, short stature in 50%, and reduced total body and lumbar spine bone mineral density (BMD) (height adjusted Z-score < -1) in 57% and 21%, respectively. Vitamin D deficiency was seen in 71%. Short stature was associated with younger age at HCT and gonadal failure was associated with older age at HCT. Insulin resistance was associated with increased percent fat mass and increased android/gynoid ratio by dual energy X-ray absorptiometry. Hypothyroidism, short stature, and reduced total body BMD were more prevalent in patients with FA compared with patients with hematologic malignancies. We recommend an assessment before transplantation and close follow-up afterwards to ensure proper clinical management. Future studies should continue to explore the impact of HCT on endocrinopathies in FA patients.

Endocrine disorders in Fanconi anemia: recommendations for screening and treatment

CONTEXT

Endocrine problems are common in patients with Fanconi anemia (FA). About 80% of children and adults with FA have at least one endocrine abnormality, including short stature, GH deficiency, abnormal glucose or insulin metabolism, dyslipidemia, hypothyroidism, pubertal delay, hypogonadism, or impaired fertility. The goal of this report is to provide an overview of endocrine abnormalities and guidelines for routine screening and treatment to allow early diagnosis and timely intervention.

EVIDENCE ACQUISITION

This work is based on a comprehensive literature review, including relevant articles published between 1971 and 2014, and proceedings of a Consensus Conference held by the Fanconi Anemia Research Fund in 2013.

EVIDENCE SYNTHESIS

The panel of experts collected published evidence and discussed its relevance to reflect current information about the endocrine care of children and adults with FA before the Consensus Conference and through subsequent deliberations that led to the consensus.

CONCLUSIONS

Individuals with FA should be routinely screened for endocrine abnormalities, including evaluation of growth; glucose, insulin, and lipid metabolism; thyroid function; puberty; gonadal function; and bone mineral metabolism. Inclusion of an endocrinologist as part of the multidisciplinary patient care team is key to providing comprehensive care for patients with FA.

Role of immune system in type 1 diabetes mellitus pathogenesis

The immune system is the body's natural defense system against invading pathogens. It protects the body from infection and works to communicate an individual's well-being through a complex network of interconnected cells and cytokines. This system is an associated host defense. An uncontrolled immune system has the potential to trigger negative complications in the host. Type 1 diabetes results from the destruction of pancreatic β-cells by a β-cell-specific autoimmune process. Examples of β-cell autoantigens are insulin, glutamic acid decarboxylase, tyrosine phosphatase, and insulinoma antigen. There are many autoimmune diseases, but type 1 diabetes mellitus is one of the well-characterized autoimmune diseases. The mechanisms involved in the β-cell destruction are still not clear; it is generally believed that β-cell autoantigens, macrophages, dendritic cells, B lymphocytes, and T lymphocytes are involved in the β-cell-specific autoimmune process. It is necessary to determine what exact factors are causing the immune system to become unregulated in such a manner as to promote an autoimmune response.

Endocrine complications after busulphan and cyclophosphamide based hematopoietic stem cell transplant: A single tertiary care centre experience

INTRODUCTION

Endocrine complications are common after hematopoietic stem cell transplant (HSCT). Although HSCT is performed at various centers in India, no study is available for endocrine dysfunctions among them. This study was carried out with the objective to evaluate endocrine dysfunction among patients undergone HSCT in the past.

MATERIALS AND METHODS

We carried out a cross-sectional study in a 50 post-HSCT recipients (39 allogenic, 11 autologous). All relevant data were collected from patient's records. Samples for hormonal estimation were collected and stimulation tests for cortisol and growth hormone were interpreted based on peak values achieved during insulin tolerance test.

RESULTS

The mean age of patients was 26.3 ± 16.9 years (range 4-74). Adrenal insufficiency (AI) was present in 60%, hypergonadotropic hypogonadism (HH) in 60%, growth hormone deficiency (GHD) in 54%, hypothyroidism in 4%, hyperprolactinemia in 4%, new onset diabetes after transplant in 4%, and impaired fasting glucose in 6%. Multiple endocrine complications were common. GHD was present in 77% of children (n = 22) although height standard deviation score was not statistically different compared to those who didn't have GHD. HH was present in 36% of children. In adults (n = 28), 36% had GHD, all females had HH, and 89% of males had HH. Germ cell dysfunction with compensated Leydig cell dysfunction was the most common pattern of HH in males. Fifteen patients had graft versus host disease (GVHD). GVHD had no bearing on development of endocrine deficiencies. AI was related to duration after and type of transplant, but was unrelated to steroid intake.

CONCLUSIONS

Endocrine manifestations are common after HSCT; they can occur as early or late complications. All HSCT recipients should have endocrine evaluation as per prevailing guidelines.

Amniotic stem cell transplantation therapy for type 1 diabetes: A case report

This case report presents an evaluation of the clinical effects of an allogeneic amniotic cell transplant for the treatment of type 1 diabetes mellitus. A 26-year-old man with type 1 diabetes was treated with stem cells isolated from his neonatal son’s amniotic membrane, collected at birth (2 × 107 cells). The cells, which expressed high levels of cluster of differentiation (CD) 133 and CD34 as assessed by flow cytometry, were infused into the pancreatic dorsal artery through the left femoral artery. The main study outcome was the change in exogenous insulin requirements, which began to decrease 3 days after transplantation. At 3 months post-transplantation, the patient was insulin independent and remained so for 6.2 months. During a 36-month follow-up, the patient’s blood glucose remained under control and insulin treatment was readjusted to a dosage of 8 IU/day. These preliminary data suggest that amniotic membrane stem cell transplantation can improve islet-cell function in response to glucose in vivo, although an alternative explanation (such as a honeymoon period due to reduced glucose toxicity) also has to be considered.

Endocrine phenotype of children and adults with Fanconi anemia

BACKGROUND

Features of Fanconi anemia (FA) are well known, including bone marrow failure, congenital anomalies such as radial anomalies, renal and ear anomalies, tracheo-esophageal fistula, imperforate anus, and elevated risk for cancer. We sought to further characterize the endocrine phenotype in children and adults with FA.

PROCEDURE

Clinically indicated endocrine evaluation data from 120 persons with FA, including 78 children (43 female) and 42 young adults (who had achieved adult height, 19 female), were entered in an institutional review board-approved database. Data were analyzed according to gender, birth weight, FA complementation group, and whether or not the patient had completed linear growth or had undergone hematopoietic cell transplant, using Wilcoxon Rank Sum or Chi-square, as appropriate.

RESULTS

Overall, 60% of children and 58% of adults with FA had short stature, 68% of children and 30% of adults had glucose intolerance, 61% of children and 37% of adults had mild hypothyroidism, and 40% of adults had evidence of hypogonadism (not possible to fully assess in children). In general, bone mineral density (BMD) was normal in adults, while BMD in children was normal when results were adjusted for bone size/thickness using height age.

CONCLUSIONS

We have evaluated in detail children and adults with FA for their growth and endocrine function. Overall, 79% of children and adults with FA had one or more endocrine abnormality.

Bone mineral density is normal in children with Fanconi anemia

BACKGROUND

Conflicting data exist regarding whether low bone mineral density (BMD) is associated with Fanconi anemia (FA). The current study identified the frequency of low BMD in FA, expecting low BMD even in childhood and before HCT.

PROCEDURE

Thirty-seven FA patients (18 prior HCT, 19 no prior HCT), participating in an IRB-approved database, had clinical assessment of DXA of lumbar spine BMD. Four had used androgens, one later underwent HCT. Most had used glucocorticoids after HCT (prolonged in five), and one more with no HCT. BMD [in standard deviation units from mean for age (SD), gender, and ethnicity (BMD Z-score)] was then adjusted for height age, and separately for bone maturation (BA). Data were collected for height SD, pubertal stage, and duration since HCT.

RESULTS

BMD Z-score (without adjustment) was <-1 SD in half of FA children. BA-adjusted BMD Z-score was similar. (BA was not usually delayed, although most patients were short.) In contrast, height age-adjusted BMD Z-score was normal in most with FA (only below -2.0 in one child after prolonged glucocorticoids). Mean duration after HCT until DXA test was 6.2 years (median 4.2 years, range 1-18 years).

CONCLUSIONS

Children and adolescents with FA have normal BMD prior to and after HCT, when DXA results are adjusted for bone size/height age. In contrast, BA-adjustment of BMD was not useful in this population. Individual BMD results may be influenced by gonadal function, transplantation status, and prolonged glucocorticoid therapy.

A low frequency of pancreatic islet insulin-expressing cells derived from cord blood stem cell allografts in humans

AIMS/HYPOTHESIS

We sought to establish if stem cells contained in cord blood cell allografts have the capacity to differentiate into insulin-expressing beta cells in humans.

METHODS

We studied pancreases obtained at autopsy from individuals (n = 11) who had prior opposite-sex cord blood transplants to reconstitute haematopoiesis. Pancreatic tissue sections were stained first by XY-fluorescence in situ hybridisation and then insulin immunohistochemistry. Pancreases obtained at autopsy from participants without cord blood cell infusions served as controls (n = 11).

RESULTS

In the men with prior transplant of female cord blood, there were 3.4 ± 0.3% XX-positive insulin-expressing islet cells compared with 0.32 ± 0.05% (p < 0.01) in male controls. In women with prior transplant of male cord blood cells we detected 1.03 ± 0.20% XY insulin-expressing islet cells compared with 0.03 ± 0.03 in female controls (p < 0. 001).

CONCLUSIONS/INTERPRETATION

Cord blood stem cells have the capacity to differentiate into insulin-expressing cells in non-diabetic humans. It remains to be established whether these cells have the properties of beta cells.