Pineocytoma in a child with Pallister-Killian syndrome: a case report and review of the literature

Pallister-Killian syndrome (PKS; OMIM #601803) is a rare genetic disorder typically characterized by developmental delay, seizures, sparse temporal hair, and facial dysmorphisms. PKS is most frequently caused by mosaic supernumerary isochromosome 12p. Here, we report a 27-month-old girl with a prenatal diagnosis of PKS and a histopathological diagnosis of pineocytoma.

Targeting Group 3 Medulloblastoma by the Anti-PRUNE-1 and Anti-LSD1/KDM1A Epigenetic Molecules

Medulloblastoma (MB) is a highly malignant childhood brain tumor. Group 3 MB (Gr3 MB) is considered to have the most metastatic potential, and tailored therapies for Gr3 MB are currently lacking. Gr3 MB is driven by PRUNE-1 amplification or overexpression. In this paper, we found that PRUNE-1 was transcriptionally regulated by lysine demethylase LSD1/KDM1A. This study aimed to investigate the therapeutic potential of inhibiting both PRUNE-1 and LSD1/KDM1A with the selective inhibitors AA7.1 and SP-2577, respectively. We found that the pharmacological inhibition had a substantial efficacy on targeting the metastatic axis driven by PRUNE-1 (PRUNE-1-OTX2-TGFβ-PTEN) in Gr3 MB. Using RNA seq transcriptomic feature data in Gr3 MB primary cells, we provide evidence that the combination of AA7.1 and SP-2577 positively affects neuronal commitment, confirmed by glial fibrillary acidic protein (GFAP)-positive differentiation and the inhibition of the cytotoxic components of the tumor microenvironment and the epithelial-mesenchymal transition (EMT) by the down-regulation of N-Cadherin protein expression. We also identified an impairing action on the mitochondrial metabolism and, consequently, oxidative phosphorylation, thus depriving tumors cells of an important source of energy. Furthermore, by overlapping the genomic mutational signatures through WES sequence analyses with RNA seq transcriptomic feature data, we propose in this paper that the combination of these two small molecules can be used in a second-line treatment in advanced therapeutics against Gr3 MB. Our study demonstrates that the usage of PRUNE-1 and LSD1/KDM1A inhibitors in combination represents a novel therapeutic approach for these highly aggressive metastatic MB tumors.

Extra-neural metastases in pediatric diffuse midline gliomas, H3 K27-altered: presentation of two cases and literature review

Introduction

Pediatric diffuse midline gliomas (DMG), H3 K27- altered, are the most aggressive pediatric central nervous system (CNS) malignancies. Disease outcome is dismal with a median survival of less than one year. Extra-neural metastases are an unusual occurrence in DMG and have been rarely described.

Methods and results

Here, we report on two pediatric patients affected by DMG with extra-neural dissemination. Their clinical, imaging, and molecular characteristics are reported here. An 11-year-old male 5 months after the diagnosis of diffuse intrinsic pontine glioma (DIPG) developed metastatic osseous lesions confirmed with computed tomography (CT) guided biopsy of the left iliac bone. The patient died one month after the evidence of metastatic progression. Another 11-year-old female was diagnosed with a cerebellar H3K27- altered DMG. After six months, she developed diffuse sclerotic osseous lesions. A CT-guided biopsy of the right iliac bone was non-diagnostic. She further developed multifocal chest and abdominal lymphadenopathy and pleural effusions. Droplet digital polymerase chain reaction (ddPCR) on pleural effusion revealed the presence of H3.3A mutation (c.83A>T, p.K28M). The patient died 24 months after the diagnosis of DMG and 3 months after the evidence of metastatic pleural effusion.

Discussion

Extra-neural metastasis of DMG is a rare event and no standard therapy exists. An accurate and early diagnosis is necessary in order to develop a personalized plan of treatment. Further research is needed to gain further insights into the molecular pathology of DMG, H3K27- altered and improve the quality of life and the final outcome of patients with this deadly disease.

DICER1 Syndrome: A Multicenter Surgical Experience and Systematic Review

DICER1 syndrome is a rare genetic disorder that predisposes patients to the development of malignant and non-malignant diseases. Presently, DICER1 syndrome diagnosis still occurs late, usually following surgical operations, affecting patients' outcomes, especially for further neoplasms, which are entailed in this syndrome. For this reason, herein we present a multicenter report of DICER1 syndrome, with the prospective aim of enhancing post-surgical surveillance. A cohort of seven patients was collected among the surgical registries of Pediatric Surgery at the University of Pisa with the General and Oncologic Surgery of Federico II, University of Naples, and the Pediatric Surgery, Regina Margherita Hospital, University of Turin. In each case, the following data were analyzed: sex, age at diagnosis, age at first surgery, clinical features, familial, genetic investigations, and follow-up. A comprehensive literature review of DICER1 cases, including case reports and multicenter studies published from 1996 to June 2022, was performed. Eventually, the retrieved data from the literature were compared with the data emerging from our cohort of patients.

Endoscopic ultrasonic resection of calcified tumor of the third ventricle

In this video, the authors present ultrasonic resection of calcified tumor of the third ventricle in a 12-year-old boy. He presented to the emergency department with a 1-week history of headache, drowsiness, and bilateral papilledema. Despite extensive calcification visible on a CT scan, a minimally invasive pure endoscopic approach was chosen. The use of an ultrasonic aspirator allows fast and safe removal of the tumor. The histological diagnosis was a low-grade glioneuronal tumor. In conclusion, the endoscopic ultrasonic aspirator is a useful tool to resect tumors in the ventricular system. The presence of calcifications within the tumor does not contraindicate an endoscopic approach. The video can be found here: https://stream.cadmore.media/r10.3171/2023.1.FOCVID22143.

Tumors of Choroid Plexus and Other Ventricular Tumors

Tumors arising inside the ventricular system are rare but represent a difficult diagnostic and therapeutic challenge. They usually are diagnosed when reaching a big volume and tend to affect young children. There is a wide broad of differential diagnoses with significant variability in anatomical aspects and tumor type. Differential diagnosis in tumor type includes choroid plexus tumors (papillomas and carcinomas), ependymomas, subependymomas, subependymal giant cell astrocytomas (SEGAs), central neurocytomas, meningiomas, and metastases. Choroid plexus tumors, ependymomas of the posterior fossa, and SEGAs are more likely to appear in childhood, whereas subependymomas, central neurocytomas, intraventricular meningiomas, and metastases are more frequent in adults. This chapter is predominantly focused on choroid plexus tumors and radiological and histological differential diagnosis. Treatment is discussed in the light of the modern acquisition in genetics and epigenetics of brain tumors.

DDDR-32. A NEW IMMUNOMODULATORY FUNCTION OF PYRIDO-PYRIMIDINE DERIVATIVES TO IMPAIR METASTATIC GROUP 3 MEDULLOBLASTOMA IN VIVO

Medulloblastoma (MB) is an embryonal tumor of the cerebellum constituting ~ 20% of pediatric brain tumors. To date, four MB molecular groups (further stratified in twelve subtypes) have been described. Among them, Groups 3 and Group 4 MB have the poorest prognosis due to their high metastatic potential. Recently, we have reported a metastatic axis driven by Prune1 overexpression in MB Group3 characterized by canonical TGF-β signaling enhancement and epithelial-mesenchymal transition. Here, we have developed a new not toxic pyrido-pyrimidine derivative with the ability to impair Prune-1-driven-axis, thus ameliorating the survival rate of a murine model of metastatic MB Group3 characterized by overexpression of human Prune1 gene in the cerebellum (under the control of MATH1 promoter). Of importance, this small molecule also is showing immunomodulatory functions thus inhibiting the conversion of tumor-infiltrating T lymphocytes (TILs) to immunosuppressive regulatory T cells (Tregs) in vivo via impairing the secretion of inflammatory cytokines from MB cells. Furthermore, this molecule can also act synergistically with the currently used modified-intensity chemotherapy (e.g. in PNET5 use of Vincristine) or potential in the combination with epigenetics drugs (e.g., LSD1/KDM1A inhibitors). Altogether these results are of importance for future targeted therapies of high-risk metastatic MB. Acknowledgments: We thank for funding support: the Italian Association for Cancer Research (AIRC) Grant IG no. 22129 (M.Z.) and Lazio Innova Grant n. 85-2017-14785 (FT; MZ)

DIPG-04. Feasibility and early results of phase 2 open label randomized study of radiotherapy(RT), concomitant nimotuzumab and vinorelbine and re-irradiation at relapse, versus multiple elective radiotherapy courses with concomitant vinorelbine and nimotuzumab for newly diagnosed childhood and adolescence Diffuse intrinsic Pontine Glioma (DIPG)

BACKGROUND: The purposes of this trial were to evaluate the feasibility, response, PFS/OS of a randomized study comparing two different RT schedules for DIPG while administering the same systemic treatment. METHODS: Patients: 2-21 years-old with a not-pretreated radiologically verified DIPG (MRI blindly reviewed at diagnosis and every 12 weeks thereafter) and symptoms duration below 6 months. Biopsy was required if suggested by atypical imaging. Vinorelbine 20 mg/m2+nimotuzumab 150 mg/m2 were administered weekly for 12 weeks; thereafter every other week until tumor progression or for up to 2 years. Standard(ST) arm included focal RT at total dose of 54Gy (1.8Gy/day); for local progression re-irradiation was proposed at 19.8Gy, in case of dissemination craniospinal irradiation(CSI) at 36Gy was adopted. Experimental(SP) arm included three elective courses of RT at defined timepoints at 36Gy, 19.8Gy and 19.8Gy with possible reirradiation for relapse at 9 Gy. Incidences of local(L) and distant(D) progression were assessed in a competing risk setting. RESULTS: Aggregated preliminary results are given for 4 Italian centers. 54 pts were screened and 51 included, 27 in ST, 28 males, median age 7 years (range 3-17). Median time of observation was 17.9 months. Twelve patients needed a shunt, 10 during treatment; 20 were biopsied, in 18 cases according local protocols. 19/20 tumors had H3.3 K27 mutation. 41 relapsed, 28 locally, 13 with a component of dissemination. 36 died, one for tracheotomy bleeding. SP irradiation was feasible and never produced significant radionecrosis. Median EFS/OS were 7.3/12.9 months, respectively; EFS/OS at 1 year were 19.0%/57.3%, not differing between patients with local vs. disseminated relapses. Patients submitted to biopsies had more dissemination (P=0.04) and less local progression (P=0.077). CONCLUSIONS: Treatment was feasible and OS confirmed previous results obtained in a single center. Randomization results will be later reported.

Giant intracranial infantile myofibromatosis of the skull base: report of two cases

Infantile myofibromatosis is a rare and nonmalignant pediatric tumor of myofibroblastic origin that may occur in solitary or multifocal forms. Soft tissue of the head and neck, trunk, and extremities, skeleton, and viscera are usually involved. Intracranial involvement is reported to be extremely rare, and its clinical picture has been poorly characterized. We present two cases of giant infantile myofibromatosis of the skull base with intracranial involvement. The first case with prenatal diagnosis involved extensively the extradural space of the occipital region and was previously treated by chemotherapy for a previous diagnosis of hemangioperycitoma. Tumor was removed at the age of 5 months and no recurrence was observed during the 3-year follow-up. The second case in a 2-year-old baby involved the anterior cranial base, the nasal cavity, the right orbit, and presented massive involvement of the anterior cranial fossa. Surgery allowed complete removal and a recurrence-free period of 7 years after surgery. Treatment options for these unusual cases are presented and details of histological diagnosis are discussed.

The Clinical and Prognostic Impact of the Choice of Surgical Approach to Fourth Ventricular Tumors in a Single-Center, Single-Surgeon Cohort of 92 Consecutive Pediatric Patients

Objective

A single-institution cohort of 92 consecutive pediatric patients harboring tumors involving the fourth ventricle, surgically treated via the telovelar or transvermian approach, was retrospectively reviewed in order to analyze the impact of surgical route on surgery-related outcomes and cumulative survival.

Methods

Clinical, radiological, surgical, and pathology details were retrospectively analyzed. We selected n = 6 surgery-related clinical and radiological outcomes: transient and permanent neurological deficits, duration of assisted ventilation, postoperative new onset medical events, postoperative cerebellar mutism, and extent of resection. We built univariate and multivariate logistic models to analyze the significance of relationships between the surgical routes and the outcomes. Cumulative survival (CS) was estimated by the cohort approach.

Results

There were 53 girls and 39 boys (mean age, 83 months). Telovelar approach was performed in 51 cases and transvermian approach in 41 cases. Early postoperative MRI studies showed complete removal in 57 cases (62%) and measurable residual tumor in 35 cases (38%). The average tumor residual volume was 1,316 cm³ (range, 0.016-4.231 cm³; median value, 0.9875 cm³). Residual disease was more often detected on immediate postop MRI after telovelar approach, but the difference was not significant. Cerebellar mutism was observed in 10 cases (11%). No significant difference in the onset of cerebellar mutism was detected between telovelar and transvermian approach. The choice of surgical approach did not significantly modify any other postoperative outcome and 1-/3-year CS of high-grade surgically treated tumors.

Conclusions

With the limitation of a single-center, single-surgeon retrospective series, our findings offer significant data to reconsider the real impact of the choice of the surgical route to the fourth ventricle on the incidence of cerebellar mutism and surgery-related morbidity. This seems to be in line with some recent reports in the literature. Surgical approach to the fourth ventricle should be individualized according to the location of the tumor, degree of vermian infiltration, and lateral and upward extension. Telovelar and transvermian approaches should not be considered alternative but complementary. Pediatric neurosurgeons should fully master both approaches and choose the one that they consider the best for the patient based on a thorough and careful evaluation of pre-operative imaging.

Diencephalic Syndrome Due to Optic Pathway Gliomas in Pediatric Patients: An Italian Multicenter Study

Diencephalic syndrome (DS) is a rare pediatric condition associated with optic pathway gliomas (OPGs). Since they are slow-growing tumors, their diagnosis might be delayed, with consequences on long-term outcomes. We present a multicenter case series of nine children with DS associated with OPG, with the aim of providing relevant details about mortality and long-term sequelae. We retrospectively identified nine children (6 M) with DS (median age 14 months, range 3–26 months). Four patients had NF1-related OPGs. Children with NF1 were significantly older than sporadic cases (median (range) age in months: 21.2 (14–26) versus 10 (3–17); p = 0.015). Seven tumors were histologically confirmed as low-grade astrocytomas. All patients received upfront chemotherapy and nutritional support. Although no patient died, all of them experienced tumor progression within 5.67 years since diagnosis and were treated with several lines of chemotherapy and/or surgery. Long-term sequelae included visual, pituitary and neurological dysfunction. Despite an excellent overall survival, PFS rates are poor in OPGs with DS. These patients invariably present visual, neurological or endocrine sequelae. Therefore, functional outcomes and quality-of-life measures should be considered in prospective trials involving patients with OPGs, aiming to identify “high-risk” patients and to better individualize treatment.

Symptomatic malignant spinal cord compression in children: a single-center experience

Background

Malignant spinal cord compression (MSCC) is associated withpoor prognosis and may lead to permanent paralysis, sensory loss, and sphincter dysfunction. Very limited data are available on incidence and etiology of MSCC in pediatric population. We aimed to examine etiology, clinical presentation and treatment of pediatric patient with MSCC admitted to the Santobono-Pausilipon Children’s Hospital, Naples, Italy.

Methods

Forty-four children under 18 yearsadmitedsince 2007 and assessed for MSCC clinical presentations, evaluation, and treatment.were retrospectively collected from our institutional pediatric oncology and neurosurgery database.

Results

The median age at time of MSCC diagnosis was 52 months, with a peak in young (≤3 years) patients. The leading cause of MSCC was extramedullary tumors (63.6%), in particular neuroblastoma (27.2%) followed by Ewing sarcomas (15.9%). Cord compression was the presenting feature of a new malignancy in 33 (75%) patients, and a consequence of metastatic disease progression or relapse in the remaining 11 (25%) patients. Motor deficit was the initial symptoms of spinal compression in all patients, while pain was present in about 60% of patients, followed by sphincteric deficit (43.2%). The primary tumor site was located in the neck in 3 (6.8%) patients, thorax in 16 (36.4%), cervico-thoracic region in 3 (6.8%), thoraco-lumbar region in 8 (18.2%), abdomen in 5 (11.4%), lumbar-sacral region in 7 (15.9%) and thoracic-lumbar-sacral region in 1 (2.3%). The median length of the interval between symptom onset and tumor diagnosis varied widely from 0 to 360 days in the entire population, however this interval was significantly shorter in patients with known neoplasia in comparisonto patients with new diagnosis (at relapse 7 days [interquartile range 3–10] vs at diagnosis 23 days [7–60]). Pre and post-operative spine magnetic resonance imagingwas performed in all cases, and most(95%) patients underwent neurosurgical treatment as first treatment. Severe motor deficit was associated with younger age and severe motor deficit at diagnosis was associated withworst motor outcomes at discharge from neurosurgery. Patients with progression or relapsed disease showed a worst prognosis, while the majority of patients (70.5%) were alive at 5 years after diagnosis.

Conclusions

The natural history of MSCC in children is associated to permanent paralysis, sensory loss, and sphincter dysfunction, thus prompt diagnosis and correct management are needed to minimize morbidity. Treatment strategies differed widely among cancer types and study groups in the absence of optimal evidence-based treatment guidelines. When the diagnosis is uncertain, surgery provides an opportunity to biopsy the lesion in addition to treating the mass.

Porcine vs bovine surfactant therapy for preterm neonates with RDS: systematic review with biological plausibility and pragmatic meta-analysis of respiratory outcomes

Background

Bovine surfactants are known to be clinically equivalent but it is unclear if porcine or bovine surfactants at their licensed dose should be preferred to treat respiratory distress syndrome in preterm neonates.

Methods

We performed a comprehensive review of biochemical and pharmacological features of surfactants to understand the biological plausibility of any clinical effect. We then performed a pragmatic meta-analysis comparing internationally marketed porcine and bovine surfactants for mortality and respiratory outcomes. Search for randomised controlled trials with no language/year restrictions and excluding “grey” literature, unpublished or non-peer reviewed reports was conducted, following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and the most recent methodological recommendations.

Results

Sixteen articles were included in the review and 14 in the meta-analysis (1491 neonates). 200 mg/kg poractant-α (a porcine surfactant) was associated with lower BPD/mortality (OR 0.632[95%CI:0.494, 0.809];p < 0.001),BPD (OR 0.688[95%CI:0.512, 0.925];p = 0.013), retreatment (OR 0.313[95%CI:0.187, 0.522];p < 0.0001), airleaks (OR 0.505[95%CI:0.308, 0.827];p = 0.006) and lung haemorrhage (OR 0.624[95%CI:0.388, 1];p = 0.051). Gestational age is associated with effect size for BPD (coefficient: 0.308 [95%CI:0.063, 0.554];p = 0.014) and surfactant retreatment (coefficient: -0.311 [95%CI:-0.595, − 0.028];p = 0.031).

Conclusion

200 mg/kg poractant-α is associated with better respiratory outcomes compared to bovine surfactants at their licensed dose. The effect of poractant-α on BPD and surfactant retreatment is greater at lowest and highest gestational ages, respectively.

Trial registration

PROSPERO n.42017075251.

Electronic supplementary material

The online version of this article (10.1186/s12931-019-0979-0) contains supplementary material, which is available to authorized users.

Pediatric lung adenocarcinoma presenting with brain metastasis: a case report

BACKGROUND

Diagnosis and treatment of primary lung adenocarcinoma in children remains challenging given its rarity. Here we highlight the clinical history, pathological evaluation, genomic findings, and management of a very young patient with metastatic lung adenocarcinoma.

CASE PRESENTATION

A 10-year-old white girl presented with brain metastases due to primary pulmonary adenocarcinoma. Next generation sequencing analysis with "Comprehensive Cancer Panel" highlighted the presence of multiple non-targetable mutations in the FLT4, UBR5, ATM, TAF1, and GUCY1A2 genes. She was treated aggressively with chemotherapy, surgery, and radiation therapy for local and distant recurrence. Eventually, therapy with nivolumab was started compassionately, and she died 23 months after diagnosis.

CONCLUSIONS

Extremely rare cancers in children such as lung adenocarcinoma need accurate and specific diagnosis in order to develop an optimal plan of treatment. It is also necessary to underline that "children are not little adults," thus implying that an adult-type cancer in the pediatric population might have a different etiopathogenesis. Diagnostic confirmation and primary treatment of such rare conditions should be centralized in reference centers, collaborative networks, or both, with multidisciplinary approaches and very specific expertise.

Lung Ultrasound Score Predicts Surfactant Need in Extremely Preterm Neonates

BACKGROUND AND OBJECTIVES

There are several lung ultrasound scores (LUS) for evaluating lung aeration in critically ill adults with restrictive lung disorders. A modified LUS adapted for neonates correlates well with oxygenation and is able to be used to predict the need for surfactant in preterm neonates with respiratory distress syndrome (RDS). However, no data are available for extremely preterm neonates for whom timely surfactant administration is especially important. We hypothesized that LUS might be reliable in extremely preterm neonates with RDS who are treated with continuous positive airway pressure. We aimed to determine the diagnostic accuracy of LUS in predicting the need for surfactant treatment and re-treatment in this population.

METHODS

We performed a prospective cohort diagnostic accuracy study between 2015 and 2016 in a tertiary-care academic center. Inborn neonates at ≤30 weeks' gestation with RDS treated with continuous positive airway pressure were eligible. Surfactant was given on the basis of oxygen requirement thresholds derived from European guidelines, and a LUS was not used to guide surfactant treatment. We calculated the LUS after admission and analyzed its diagnostic accuracy to predict surfactant treatment and re-treatment.

RESULTS

We enrolled 133 infants; 68 (51%) received 1 dose of surfactant and 19 (14%) received 2 surfactant doses. A LUS is significantly correlated with oxygenation index (ρ = 0.6; P < .0001) even after adjustment for gestational age (P < .0001). A LUS can be used to accurately predict the need for the first surfactant dose (area under the curve = 0.94; 95% confidence interval: 0.90-0.98; P < .0001) and also the need for surfactant redosing (area under the curve = 0.803; 95% confidence interval: 0.72-0.89; P < .0001). The global accuracy for the prediction of surfactant treatment and re-treatment is 89% and 72%, respectively.

CONCLUSIONS

LUS may be used to predict the need for surfactant replacement in extremely preterm neonates with RDS.

Long-term effects of growth hormone (GH) replacement therapy on hematopoiesis in a large cohort of children with GH deficiency

The aim of our prospective case-control study was to evaluate long-term effects of GH replacement therapy on erythrocytes parameters, leukocytes, and platelets numbers in a large cohort of children with isolated GH deficiency (GHD). Hemoglobin (Hb) concentration, hematocrit (Hct), mean corpuscular volume, mean corpuscular hemoglobin, red cell distribution width, number of erythrocytes, leukocytes, neutrophils, lymphocytes, monocytes and platelets, ferritin, and C-reactive protein were evaluated in 85 children with isolated GHD (10.20 ± 3.50 years) before and annually during the first 5 years of GH replacement therapy and in 85 healthy children age and sex comparable to patients during 5 years of follow-up. Compared with controls, GHD children at study entry showed lower Hb (-1.18 ± 0.87 vs. -0.40 ± 0.90 SDS, p < 0.0001), red cells number (-0.24 ± 0.81 vs. 0.25 ± 1.14 SDS, p < 0.0001), and Hct (-1.18 ± 0.86 vs. -0.68 ± 0.99 SDS, p < 0.0001). Twelve GHD patients (14 %) showed a normocytic anemia. GH therapy was associated with a significant increase in Hb, Hct, and red cells number which became all comparable to controls within the first 2 years of treatment. Moreover, hemoglobin levels normalized in all anemic GHD patients after 5 years of therapy. No difference between patients and controls was found in leukocytes and platelets numbers neither at baseline nor during the study. GHD in childhood is associated with an impairment of erythropoiesis which causes a normocytic anemia in a considerable percentage of patients. GH replacement therapy exerts a beneficial effect leading to a significant increase of erythrocytes parameters and recovery from anemia. Neither GHD nor GH replacement treatment exerts effects on leukocytes or platelets numbers.

Novel Findings into AIRE Genetics and Functioning: Clinical Implications

Autoimmune polyendocrinopathy candidiasis ectodermal dystrophy (APECED), formerly known as autoimmune polyendocrine syndrome type 1, is a paradigm of a monogenic autoimmune disease caused by mutations of a gene, named autoimmune regulator (AIRE). AIRE acts as a transcription regulator that promotes immunological central tolerance by inducing the ectopic thymic expression of many tissue-specific antigens. Although the syndrome is a monogenic disease, it is characterized by a wide variability of the clinical expression with no significant correlation between genotype and phenotype. Indeed, many aspects regarding the exact role of AIRE and APECED pathogenesis still remain unraveled. In the last decades, several studies in APECED and in its mouse experimental counterpart have revealed new insights on how immune system learns self-tolerance. Moreover, novel interesting findings have extended our understanding of AIRE's function and regulation thus improving our knowledge on the pathogenesis of APECED. In this review, we will summarize recent novelties on molecular mechanisms underlying the development of APECED and their clinical implications.

Investigation of chronic diarrhoea in infancy

Diarrhoea in infants and young children is defined as >200g/day of stools, and occurs when there is an imbalance between intestinal fluids absorption and secretion. This may be caused by either a decreased absorption (osmotic diarrhoea) or an increased secretion (secretory diarrhoea). Chronic diarrhoea defines intestinal loss of water and electrolytes with increased stool frequency, reduced consistency and larger volume over more than 14days. This disorder in children shows a wide range of aetiologies depending on the age. The knowledge of common and rare aetiologies is important to optimize the diagnostic approach. A stepwise approach, starting with a comprehensive history, physical examination, inspection and collection of stool samples, helps to devise appropriate diagnostic and therapeutic management. In this article we discuss the pathophysiology, aetiology and possible approach to chronic diarrhoea in infancy.

APECED: A Paradigm of Complex Interactions between Genetic Background and Susceptibility Factors

Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) is a rare autosomal recessive disease, caused by mutations of a single gene named Autoimmune regulator gene (AIRE) which results in a failure of T-cell tolerance. Central tolerance takes place within the thymus and represents the mechanism by which potentially auto-reactive T-cells are eliminated through the negative selection process. The expression of tissue-specific antigens (TSAs) by medullary thymic epithelial cells (mTECs) in the thymus is a key process in the central tolerance and is driven by the protein encoded by AIRE gene, the transcription factor autoimmune regulator (AIRE). A failure in this process caused by AIRE mutations is thought to be responsible of the systemic autoimmune reactions of APECED. APECED is characterized by several autoimmune endocrine and non-endocrine manifestations and the phenotype is often complex. Although APECED is the paradigm of a monogenic autoimmune disorder, it is characterized by a wide variability of the clinical expression even between siblings with the same genotype, thus implying that additional mechanisms, other than the failure of Aire function, are involved in the pathogenesis of the disease. Unraveling open issues of the molecular basis of APECED, will help improve diagnosis, management, and therapeutical strategies of this complex disease.

Comparative evaluation of therapy with L-thyroxine versus no treatment in children with idiopathic and mild subclinical hypothyroidism

BACKGROUND

The question of whether children with subclinical hypothyroidism (SH) should be treated or not is controversial due to the lack of studies on outcomes of SH children treated with L-thyroxine (L-T(4)) versus those receiving no therapy.

OBJECTIVES

(a) To evaluate thyroid tests under L-T(4) and after therapy withdrawal in 69 SH children (group A) and (b) to compare our results with those recorded in 92 untreated children (group B).

DESIGN

Group A children were treated for 24 months and TSH and FT(4) levels 3 months after therapy withdrawal were compared with those measured in group B at the end of follow-up in order to investigate treatment effects.

RESULTS

The prevalence of children who had normalized TSH at the end of follow-up was higher in group A, but the prevalence of those who had normalized or maintained unchanged TSH was similar in the two groups, as was the prevalence of children who exhibited a TSH increase >10 mU/l. In group A, TSH values at 27 months were associated with baseline values.

CONCLUSIONS

(a) Two-year treatment in SH children is unable to modify posttherapy outcome of hyperthyrotropinemia; (b) therapy is unable to prevent the risk of further TSH increase after treatment withdrawal, and (c) posttherapy TSH outcome is conditioned by baseline TSH.

Genetic basis of altered central tolerance and autoimmune diseases: a lesson from AIRE mutations

The thymus is a specialized organ that provides an inductive environment for the development of T cells from multipotent hematopoietic progenitors. Self-nonself discrimination plays a key role in inducing a productive immunity and in preventing autoimmune reactions. Tolerance represents a state of immunologic nonresponsiveness in the presence of a particular antigen. The immune system becomes tolerant to self-antigens through the two main processes, central and peripheral tolerance. Central tolerance takes place within the thymus and represents the mechanism by which T cells binding with high avidity self-antigens, which are potentially autoreactive, are eliminated through so-called negative selection. This process is mostly mediated by medullary thymic epithelia cells (mTECs) and medullary dendritic cells (DCs). A remarkable event in the process is the expression of tissue-specific antigens (TSA) by mTECs driven by the transcription factor autoimmune regulator (AIRE). Mutations in this gene result in autoimmune polyendocrinopathy candidiasis ectodermal dystrophy (APECED), a rare autosomal recessive disease (OMIM 240300). Thus far, this syndrome is the paradigm of a genetically determined failure of central tolerance and autoimmunty. Patients with APECED have a variable pattern of autoimmune reactions, involving different endocrine and nonendocrine organs. However, although APECED is a monogenic disorder, it is characterized by a wide variability of the clinical expression, thus implying a further role for disease-modifying genes and environmental factors in the pathogenesis. Studies on this polyreactive autoimmune syndrome contributed enormously to unraveling several issues of the molecular basis of autoimmunity. This review focuses on the developmental, functional, and molecular events governing central tolerance and on the clinical implication of its failure.

Autoimmune polyendocrinopathy candidiasis ectodermal dystrophy: insights into genotype-phenotype correlation

Autoimmune polyendocrinopathy candidiasis ectodermal dystrophy (APECED) is a rare autosomal recessive disease, caused by mutations of a single gene named autoimmune regulator gene (AIRE) which results in a failure of T cell tolerance within the thymus. Chronic mucocutaneous candidiasis, chronic hypoparathyroidism, and Addison's disease are the hallmarks of the syndrome. APECED is also characterized by several autoimmune endocrine and nonendocrine manifestations, and the phenotype is often complex. Moreover, even though APECED is a monogenic disease, its clinical picture is generally dominated by a wide heterogeneity both in the severity and in the number of components even among siblings with the same AIRE genotype. The variability of its clinical expression implies that diagnosis can be challenging, and a considerable delay often occurs between the appearance of symptoms and the diagnosis. Since a prompt diagnosis is essential to prevent severe complications, clinicians should be aware of all symptoms and signs of suspicion. The aim of this paper is to give an overview on the clinical presentation and diagnostic criteria of APECED and to focus on current knowledge on genotype-phenotype correlation.