Non-Graft-versus-Host Disease Enterocolitis Following Cord Blood Transplantation is Real, with Poorly Understood Pathophysiology, and Requires Distinct Management, with Eventual Resolution without Immune Suppression

Enterocolitis is common after cord blood transplantation (CBT) and a specific, non-graft-versus-host disease (GVHD) entity with specific histopathologic features ("cord colitis") has been described in some cases in selected series. Immune suppression is not without risk, and we have used it only when biopsy features are consistent with classical GVHD. In the absence of biopsy features of classical GVHD, our management of intestinal failure has been supportive, and we have withdrawn immune suppression to allow immune reconstitution and better prevent relapse of malignant disease and reduce infectious complications. We evaluated our approach over an 11-year period in a retrospective study of all patients at our large pediatric CBT center who experienced intestinal failure necessitating endoscopy and biopsy in the post-CBT period. We conducted a blinded histopathologic review of gastrointestinal (GI) biopsy specimens from all patients who had undergone GI endoscopy for intestinal failure in the post-CBT period. Patient records were evaluated to determine clinical HSCT course and outcome data, including mortality, relapse, and infection, as well as the duration of immune suppression and parenteral nutrition. Out of 144 patients who underwent CBT during the study period, 25 (17%) experienced intestinal failure requiring endoscopy. Thirteen patients were diagnosed with acute GVHD after blinded review of biopsy specimens, and 12 patients had non-GVHD enterocolitis. Management in the absence of GVHD on GI biopsy is supportive, with withdrawal of immune suppression in patients with malignant disease and continuing in accordance with institutional practice in those with nonmalignant disease. Compared with the GVHD cohort, the non-GVHD enterocolitis cohort had superior overall survival (91% versus 41%; P = .04) and a shorter duration of immune suppression (mean, 112 days versus 180 days; P = .049), reflecting these different management approaches. These results demonstrate that different histopathologic findings in those with intestinal failure after CBT likely indicates a different etiology from GVHD and mandates a different clinical management strategy to achieve optimal clinical outcomes.

Clinical Diversity in Focal Congenital Hyperinsulinism in Infancy Correlates With Histological Heterogeneity of Islet Cell Lesions

Background: Congenital Hyperinsulinism (CHI) is an important cause of severe and persistent hypoglycaemia in infancy and childhood. The focal form (CHI-F) of CHI can be potentially cured by pancreatic lesionectomy. While diagnostic characteristics of CHI-F pancreatic histopathology are well-recognized, correlation with clinical phenotype has not been established. Aims: We aimed to correlate the diversity in clinical profiles of patients with islet cell organization in CHI-F pancreatic tissue. Methods: Clinical datasets were obtained from 25 patients with CHI-F due to ABCC8/KCNJ11 mutations. ¹⁸F-DOPA PET-CT was used to localize focal lesions prior to surgery. Immunohistochemistry was used to support protein expression studies. Results: In 28% (n = 7) of patient tissues focal lesions were amorphous and projected into adjoining normal pancreatic tissue without clear delineation from normal tissue. In these cases, severe hypoglycaemia was detected within, on average, 2.8 ± 0.8 (range 1-7) days following birth. By contrast, in 72% (n = 18) of tissues focal lesions were encapsulated within a defined matrix capsule. In this group, the onset of severe hypoglycaemia was generally delayed; on average 46.6 ± 14.3 (range 1-180) days following birth. For patients with encapsulated lesions and later-onset hypoglycaemia, we found that surgical procedures were curative and less complex. Conclusion: CHI-F is associated with heterogeneity in the organization of focal lesions, which correlates well with clinical presentation and surgical outcomes.

Atypical Forms of Congenital Hyperinsulinism in Infancy Are Associated With Mosaic Patterns of Immature Islet Cells

OBJECTIVES

We aimed to characterize mosaic populations of pancreatic islet cells from patients with atypical congenital hyperinsulinism in infancy (CHI-A) and the expression profile of NKX2.2, a key transcription factor expressed in β-cells but suppressed in δ-cells in the mature pancreas.

PATIENTS/METHODS

Tissue was isolated from three patients with CHI-A following subtotal pancreatectomy. CHI-A was diagnosed on the basis of islet mosaicism and the absence of histopathological hallmarks of focal and diffuse CHI (CHI-D). Immunohistochemistry was used to identify and quantify the proportions of insulin-secreting β-cells and somatostatin-secreting δ-cells in atypical islets, and results were compared with CHI-D (n = 3) and age-matched control tissues (n = 3).

RESULTS

In CHI-A tissue, islets had a heterogeneous profile. In resting/quiescent islets, identified by a condensed cytoplasm and nuclear crowding, β-cells were reduced to <50% of the total cell numbers in n = 65/70 islets, whereas δ-cell numbers were increased with 85% of islets (n = 49/57) containing >20% δ-cells. In comparison, all islets in control tissue (n = 72) and 99% of CHI-D islets (n = 72) were composed of >50% β-cells, and >20% δ-cells were found only in 12% of CHI-D (n = 8/66) and 5% of control islets (n = 3/60). Active islets in CHI-A tissue contained proportions of β-cells and δ-cells similar to those of control and CHI-D islets. Finally, when compared with active islets, quiescent islets had a twofold higher prevalence of somatostatin/NKX2.2+ coexpressed cells.

CONCLUSIONS

Marked increases in NKX2.2 expression combined with increased numbers of δ-cells strongly imply that an immature δ-cell profile contributed to the pathobiology of CHI-A.

When Parents Choose Gender: Intersex, Children, and the Law

In England and Wales, it is usually lawful for those with parental responsibility to consent to treatment on children who have not acquired legal capacity, providing that they are acting in the child's best interests. Whilst in most instances this process is unproblematic and the decisions made are non-controversial, there are troubling examples where this is more problematic. The difficulties for a family with a child who has an intersex condition will be considered to illustrate that there may be cases of medical and surgical treatment where even though both parents and doctors agree on a course of action in good faith, the treatment administered may not necessarily be in the best interests of the child. Sometimes, procedures carried out on an infant apparently in their best interests may later be a cause of regret to the child as an adult. The law in England and Wales will be examined to investigate other examples of controversial treatments of young children involving legal interventions to consider whether there are any parallels and what the implications of these might be to the intersex child. A model suggested by a Columbian legal case from 1995 is discussed. The courts ruled that infantile sex assignment surgery is lawful only following very stringent consent procedures. The possibility is considered that guidelines defining the consent procedure may afford some protection for the intersex child.

An emerging opportunistic infection: fatal astrovirus (VA1/HMO-C) encephalitis in a pediatric stem cell transplant recipient

Neuroinvasive astrovirus (VA1-HMO-C) is an emerging life-threatening infection in immunocompromised hosts. We describe an 8-month-old child who died of VA1/HMO-C encephalitis following bone marrow transplantation. The diagnosis was only made post-mortem using RNA deep sequencing of the brain. Repeat analysis of the post-mortem brain tissue using polymerase chain reaction specific primers for VA1/HMO-C was positive. Astrovirus VA1/HMO-C should be included in the evaluation of patients with similar encephalitis.

Enhanced Islet Cell Nucleomegaly Defines Diffuse Congenital Hyperinsulinism in Infancy but Not Other Forms of the Disease

OBJECTIVES

To quantify islet cell nucleomegaly in controls and tissues obtained from patients with congenital hyperinsulinism in infancy (CHI) and to examine the association of nucleomegaly with proliferation.

METHODS

High-content analysis of histologic sections and serial block-face scanning electron microscopy were used to quantify nucleomegaly.

RESULTS

Enlarged islet cell nuclear areas were 4.3-fold larger than unaffected nuclei, and the mean nuclear volume increased to approximately threefold. Nucleomegaly was a normal feature of pediatric islets and detected in the normal regions of the pancreas from patients with focal CHI. The incidence of nucleomegaly was highest in diffuse CHI (CHI-D), with more than 45% of islets containing two or more affected cells. While in CHI-D nucleomegaly was negatively correlated with cell proliferation, in all other cases, there was a positive correlation.

CONCLUSIONS

Increased incidence of nucleomegaly is pathognomonic for CHI-D, but these cells are nonproliferative, suggesting a novel role in the pathobiology of this condition.

Deficiency of the myogenic factor MyoD causes a perinatally lethal fetal akinesia

Background

Lethal fetal akinesia deformation sequence (FADS) describes a clinically and genetically heterogeneous phenotype that includes fetal akinesia, intrauterine growth retardation, arthrogryposis and developmental anomalies. Affected babies die as a result of pulmonary hypoplasia. We aimed to identify the underlying genetic cause of this disorder in a family in which there were three affected individuals from two sibships.

Methods

Autosomal-recessive inheritance was suggested by a family history of consanguinity and by recurrence of the phenotype between the two sibships. We performed exome sequencing of the affected individuals and their unaffected mother, followed by autozygosity mapping and variant filtering to identify the causative gene.

Results

Five autozygous regions were identified, spanning 31.7 Mb of genomic sequence and including 211 genes. Using standard variant filtering criteria, we excluded all variants as being the likely pathogenic cause, apart from a single novel nonsense mutation, c.188C>A p.(Ser63*) (NM_002478.4), in MYOD1. This gene encodes an extensively studied transcription factor involved in muscle development, which has nonetheless not hitherto been associated with a hereditary human disease phenotype.

Conclusions

We provide the first description of a human phenotype that appears to result from MYOD1 mutation. The presentation with FADS is consistent with a large body of data demonstrating that in the mouse, MyoD is a major controller of precursor cell commitment to the myogenic differentiation programme.

Altered Phenotype of β-Cells and Other Pancreatic Cell Lineages in Patients With Diffuse Congenital Hyperinsulinism in Infancy Caused by Mutations in the ATP-Sensitive K-Channel

Diffuse congenital hyperinsulinism in infancy (CHI-D) arises from mutations inactivating the KATP channel; however, the phenotype is difficult to explain from electrophysiology alone. Here we studied wider abnormalities in the β-cell and other pancreatic lineages. Islets were disorganized in CHI-D compared with controls. PAX4 and ARX expression was decreased. A tendency toward increased NKX2.2 expression was consistent with its detection in two-thirds of CHI-D δ-cell nuclei, similar to the fetal pancreas, and implied immature δ-cell function. CHI-D δ-cells also comprised 10% of cells displaying nucleomegaly. In CHI-D, increased proliferation was most elevated in duct (5- to 11-fold) and acinar (7- to 47-fold) lineages. Increased β-cell proliferation observed in some cases was offset by an increase in apoptosis; this is in keeping with no difference in INSULIN expression or surface area stained for insulin between CHI-D and control pancreas. However, nuclear localization of CDK6 and P27 was markedly enhanced in CHI-D β-cells compared with cytoplasmic localization in control cells. These combined data support normal β-cell mass in CHI-D, but with G1/S molecules positioned in favor of cell cycle progression. New molecular abnormalities in δ-cells and marked proliferative increases in other pancreatic lineages indicate CHI-D is not solely a β-cell disorder.

Increased plasma incretin concentrations identifies a subset of patients with persistent congenital hyperinsulinism without KATP channel gene defects

Congenital hyperinsulinism causes profound hypoglycemia, which may persist or resolve spontaneously. Among 13 children with congenital hyperinsulinism, elevated incretin hormone concentrations were detected in 2 with atypical, persistent disease. We suggest that incretin biomarkers may identify these patients, and that elevated hormone levels may contribute to their pathophysiology.

Insulinoma in childhood: clinical, radiological, molecular and histological aspects of nine patients

BACKGROUND

Insulinomas are a rare cause of hyperinsulinaemic hypoglycaemia (HH) in children. The clinical features, investigations, management and histology of these rare pancreatic tumours in children have not been described in a large cohort of patients.

METHODS

We conducted a retrospective review of cases diagnosed between 2000 and 2012, presenting to two referral centres in the United Kingdom. Clinical, biochemical, imaging (magnetic resonance imaging (MRI) and 6-L-¹⁸F-fluorodihydroxyphenylalanine (¹⁸F-DOPA) PET/CT scanning) and histological data were collected.

RESULTS

Nine children (age range 2-14.5 years) were diagnosed during the study period at Great Ormond Street Hospital (n=5) and Royal Manchester Children's Hospital (n=4). The combination of abdominal MRI scan (7/8) and ¹⁸F-DOPA PET/CT scan (2/4) correctly localised the anatomical location of all insulinomas. Before surgery, diazoxide therapy was used to treat hypoglycaemia, but only four patients responded. After surgical resection of the insulinoma, hypoglycaemia resolved in all patients. The anatomical localisation of the insulinoma in each patient was head (n=4), uncinate process (n=4) and tail (n=2, one second lesion) of the pancreas. Histology confirmed the diagnosis of insulinoma with the presence of sheets and trabeculae of epithelioid and spindle cells staining strongly for insulin and proinsulin, but not for glucagon or somatostatin. Two children were positive for MEN1, one of whom had two separate insulinoma lesions within the pancreas.

CONCLUSIONS

We describe a cohort of paediatric insulinoma patients. Although rare, insulinomas should be included in the differential diagnosis of HH, even in very young children. In the absence of a single imaging modality in the preoperative period, localisation of the tumour is achieved by combining imaging techniques, both conventional and functional.

Fatal Pseudomonas septicemia and vasculitis in a premature infant

A characteristic vasculitis is an uncommon but well-recognized complication of severe Pseudomonas aeruginosa infection in the neonate. Although it is one of the most common gram-negative organisms responsible for overall nosocomial infection, it is a rare cause of intrauterine or intrapartum infection of the newborn. We describe a fatal Pseudomonas aeruginosa infection occurring in a very premature infant with widespread skin necrosis. Although this organism is relatively uncommon in the neonate, premature infants are at increased risk of infection, with a significant associated mortality. Early recognition and treatment are therefore very important.

Phenotypic diversity in the Smith-Lemli-Opitz syndrome

The phenotype of four cases of Smith-Lemli-Opitz syndrome (SLO) with proven defects in cholesterol biosynthesis are compared, and shown to be markedly disparate even between sibs, and demonstrate the dilemma for the clinician. The advent of a biochemical test for SLO has been enormously valuable in determining which patients are truly affected by the condition, but because of the wide phenotypic variation, a diagnosis on clinical features alone remains problematic.

Fatal disseminated adenovirus type 2 infection following bone marrow transplantation for Hurler's syndrome: a primary infection

A 5-month-old girl given an allogeneic bone marrow transplant for Hurler's syndrome succumbed to fatal pneumonia 5 weeks after the transplant. Adenovirus type 2 was isolated from her urine before she died. Immunoperoxidase and electron microscopical studies of liver and lungs post mortem confirmed a disseminated adenovirus infection. The serological findings and the patient's young age suggested that the infection was a primary one. The importance of considering exogenous sources of adenovirus infection in bone marrow transplant recipients is discussed.

A study of vesical adenocarcinoma, intestinal metaplasia and related lesions using mucin histochemistry

Biopsy and autopsy material from the urinary bladder was studied using PAS and PAS-D techniques to identify glycogen and neutral mucins, the alcian blue/high iron diamine method to distinguish sialo- and sulphamucins and the PB/KOH/PAS technique to localize O-acylated sialomucins. All of 10 examples of normal urothelium and both of two cases of transitional carcinoma in situ contained glycogen, but no mucin. Other lesions displayed one of two patterns of mucin production: the extracellular mucin seen focally in 17 cases of cystitis cystica consisted of sialo- and/or neutral mucins only, a pattern also displayed by mucins produced in 10 of 13 examples of transitional cell carcinomas and by three of nine tumours purely or in part adenocarcinomas. The intracellular mucins expressed in five of the 17 cases of cystitis glandularis and in all of eight cases of frank intestinal metaplasia with goblet cells displayed a colonic phenotype, with production of O-acylated sialomucins. A similar profile was expressed by six adenocarcinomas and this included tumours likely to be of vesical and also of urachal origin. It is concluded that identification of O-acylated mucins cannot distinguish between primary bladder tumours and metastases from a colonic primary, or between carcinomas of vesical and urachal origin.