Early Immunotherapy and Longer Corticosteroid Treatment Are Associated With Lower Risk of Relapsing Disease Course in Pediatric MOGAD.

BACKGROUND AND OBJECTIVES: We sought to identify early factors associated with relapse and outcome in paediatric-onset myelin oligodendrocyte glycoprotein antibody-associated disorders (MOGAD). METHODS: In a multicenter retrospective cohort of pediatric MOGAD (≤18 years), onset features and treatment were compared in patients with monophasic vs relapsing disease (including cases with follow-up ≥12 months after onset or relapse at any time) and in patients with final Expanded Disability Status Scale (EDSS) 0 vs ≥1 at last follow-up (including cases with follow-up >3 months after last event or EDSS0 at any time). Multivariable logistic regression models were used to evaluate factors associated with relapsing disease course and EDSS ≥ 1 at final follow-up. RESULTS: Seventy-five children were included (median onset age 7 years; median 30 months of follow-up). Presentation with acute disseminated encephalomyelitis was more frequent in children aged 8 years or younger (66.7%, 28/42) than in older patients (30.3%, 10/33) (p = 0.002), whereas presentation with optic neuritis was more common in children older than 8 years (57.6%, 19/33) than in younger patients (21.4%, 9/42) (p = 0.001). 40.0% (26/65) of patients relapsed. Time to first relapse was longer in children aged 8 years or younger than in older patients (median 18 vs 4 months) (p = 0.013). Factors at first event independently associated with lower risk of relapsing disease course were immunotherapy <7 days from onset (6.7-fold reduced odds of relapsing course, OR 0.15, 95% CI 0.03-0.61, p = 0.009), corticosteroid treatment for ≥5 weeks (6.7-fold reduced odds of relapse, OR 0.15, 95% CI 0.03-0.80, p = 0.026), and abnormal optic nerves on onset MRI (12.5-fold reduced odds of relapse, OR 0.08, 95% CI 0.01-0.50, p = 0.007). 21.1% (15/71) had EDSS ≥ 1 at final follow-up. Patients with a relapsing course had a higher proportion of final EDSS ≥ 1 (37.5%, 9/24) than children with monophasic disease (12.8%, 5/39) (p = 0.022, univariate analysis). Each 1-point increment in worst EDSS at onset was independently associated with 6.7-fold increased odds of final EDSS ≥ 1 (OR 6.65, 95% CI 1.33-33.26, p = 0.021). DISCUSSION: At first attack of pediatric MOGAD, early immunotherapy, longer duration of corticosteroid treatment, and abnormal optic nerves on MRI seem associated with lower risk of relapse, whereas higher disease severity is associated with greater risk of final disability (EDSS ≥ 1).

In vitro and in vivo effects of Ambroxol chaperone therapy in two Italian patients affected by neuronopathic Gaucher disease and epilepsy.

Gaucher disease (GD) is an autosomal recessive lysosomal storage disorder caused by mutations in the acid ß-glucosidase encoding gene (GBA1), resulting in the deficient activity of acid ß-glucosidase (GCase). To date, there is no approved treatment for the neurological manifestations of the disease. The role of Ambroxol as a chaperone for mutant GCase has been extensively demonstrated in vitro. Furthermore, different authors have reported beneficial effects of high doses of Ambroxol on neurological manifestations in patients affected by GD. In this report, we describe the in vitro and in vivo effects of Ambroxol in two patients (P1 and P2) affected by the neurological form of GD and epilepsy, carrying mutations already reported as responsive to the chaperone. Indeed, P1 presented the N188S mutation in compound heterozygous with a null allele (IVS2 + 1G > A) and P2 was homozygous for the L444P mutation. As expected, a beneficial effect of Ambroxol was observed in cultured fibroblasts as well as in vivo, both on epilepsy and on biomarkers of GD, in P1. However, Ambroxol was completely undefective in P2, suggesting that other factors besides the GBA1 mutation itself would be involved in the response therapy which would be difficult to predict based on the patient genotype. The present report expands the experience of Ambroxol treatment in neurological GD patients and highlights the need to in vitro test the individual response to Ambroxol even in patients carrying mutations already classified as responsive to the chaperone.

Characterization of ANGPT2 mutations associated with primary lymphedema.

Primary lymphedema is caused by developmental and functional defects of the lymphatic vascular system that result in accumulation of protein-rich fluid in tissues, resulting in edema. The 28 currently known genes causing primary lymphedema can explain <30% of cases. Angiopoietin 1 (ANGPT1) and ANGPT2 function via the TIE1-TIE2 (tyrosine kinase with immunoglobulin-like and epidermal growth factor-like domains 1 and 2) receptor complex and α5ß1 integrin to form an endothelial cell signaling pathway that is critical for blood and lymphatic vessel formation and remodeling during embryonic development, as well as for homeostasis of the mature vasculature. By screening a cohort of 543 individuals affected by primary lymphedema, we identified one heterozygous de novo ANGPT2 whole-gene deletion and four heterozygous ANGPT2 missense mutations. Functional analyses revealed three missense mutations that resulted in decreased ANGPT2 secretion and inhibited the secretion of wild-type (WT)-ANGPT2, suggesting that they have a dominant-negative effect on ANGPT2 signaling. WT-ANGPT2 and soluble mutants T299M and N304K activated TIE1 and TIE2 in an autocrine assay in human lymphatic endothelial cells. Molecular modeling and biophysical studies showed that amino-terminally truncated ANGPT subunits formed asymmetrical homodimers that bound TIE2 in a 2:1 ratio. The T299M mutant, located in the dimerization interphase, showed reduced integrin α5 binding, and its expression in mouse skin promoted hyperplasia and dilation of cutaneous lymphatic vessels. These results demonstrate that primary lymphedema can be associated with ANGPT2 mutations and provide insights into TIE1 and TIE2 activation mechanisms.

Molecular Genetics and Interferon Signature in the Italian Aicardi Goutières Syndrome Cohort: Report of 12 New Cases and Literature Review.

Aicardi-Goutières syndrome (AGS) is a genetically determined early onset encephalopathy characterized by cerebral calcification, leukodystrophy, and increased expression of interferon-stimulated genes (ISGs). Up to now, seven genes (TREX1, RNASEH2B, RNASEH2C, RNASEH2A, ADAR1, SAMHD1, IFIH1) have been associated with an AGS phenotype. Next Generation Sequencing (NGS) analysis was performed on 51 AGS patients and interferon signature (IS) was investigated in 18 AGS patients and 31 healthy controls. NGS identified mutations in 48 of 51 subjects, with three patients demonstrating a typical AGS phenotype but not carrying mutations in known AGS-related genes. Five mutations, in RNASEH2B, SAMHD1 and IFIH1 gene, were not previously reported. Eleven patients were positive and seven negatives for the upregulation of interferon signaling (IS > 2.216). This work presents, for the first time, the genetic data of an Italian cohort of AGS patients, with a higher percentage of mutations in RNASEH2B and a lower frequency of mutations in TREX1 than those seen in international series. RNASEH2B mutated patients showed a prevalence of negative IS consistent with data reported in the literature. We also identified five novel pathogenic mutations that warrant further functional investigation. Exome/genome sequencing will be performed in future studies in patients without a mutation in AGS-related genes.

Contribution of ultrarare variants in mTOR pathway genes to sporadic focal epilepsies.

Objective: We investigated the contribution to sporadic focal epilepsies (FE) of ultrarare variants in genes coding for the components of complexes regulating mechanistic Target Of Rapamycin (mTOR)complex 1 (mTORC1). Methods: We collected genetic data of 121 Italian isolated FE cases and 512 controls by Whole Exome Sequencing (WES) and single-molecule Molecular Inversion Probes (smMIPs) targeting 10 genes of the GATOR1, GATOR2, and TSC complexes. We collapsed "qualifying" variants (ultrarare and predicted to be deleterious or loss of function) across the examined genes and sought to identify their enrichment in cases compared to controls. Results: We found eight qualifying variants in cases and nine in controls, demonstrating enrichment in FE patients (P = 0.006; exact unconditional test, one-tailed). Pathogenic variants were identified in DEPDC5 and TSC2, both major genes for Mendelian FE syndromes. Interpretation: Our findings support the contribution of ultrarare variants in genes in the mTOR pathway complexes GATOR and TSC to the risk of sporadic FE and a shared genetic basis between rare and common epilepsies. The identification of a monogenic etiology in isolated cases, most typically encountered in clinical practice, may offer to a broader community of patients the perspective of precision therapies directed by the underlying genetic cause.

Correction to: The landscape of epilepsy-related GATOR1 variants.

The original version of this Article contained an error in the author list where the corresponding author Stéphanie Baulac was repeated twice. This has now been corrected in the HTML, the PDF was correct at the time of publication.

The landscape of epilepsy-related GATOR1 variants.

PURPOSE: To define the phenotypic and mutational spectrum of epilepsies related to DEPDC5, NPRL2 and NPRL3 genes encoding the GATOR1 complex, a negative regulator of the mTORC1 pathway METHODS: We analyzed clinical and genetic data of 73 novel probands (familial and sporadic) with epilepsy-related variants in GATOR1-encoding genes and proposed new guidelines for clinical interpretation of GATOR1 variants. RESULTS: The GATOR1 seizure phenotype consisted mostly in focal seizures (e.g., hypermotor or frontal lobe seizures in 50%), with a mean age at onset of 4.4 years, often sleep-related and drug-resistant (54%), and associated with focal cortical dysplasia (20%). Infantile spasms were reported in 10% of the probands. Sudden unexpected death in epilepsy (SUDEP) occurred in 10% of the families. Novel classification framework of all 140 epilepsy-related GATOR1 variants (including the variants of this study) revealed that 68% are loss-of-function pathogenic, 14% are likely pathogenic, 15% are variants of uncertain significance and 3% are likely benign. CONCLUSION: Our data emphasize the increasingly important role of GATOR1 genes in the pathogenesis of focal epilepsies (>180 probands to date). The GATOR1 phenotypic spectrum ranges from sporadic early-onset epilepsies with cognitive impairment comorbidities to familial focal epilepsies, and SUDEP.

Correction: The landscape of epilepsy-related GATOR1 variants.

The original version of this article contained an error in the spelling of the author Erik H. Niks, which was incorrectly given as Erik Niks. This has now been corrected in both the PDF and HTML versions of the article.

Sleep disorders in children with brain tumors: a pilot study based on a sleep disorder questionnaire.

PURPOSE: The aim of this study is to compare the prevalence of sleep disorders (SD) between children treated for brain tumors and healthy children, and to define the type of SD. METHODS: A case-control study was performed from October 2014 to April 2015. Inclusion criteria were patients between 2 and 16 years with "cases" defined as children affected by central nervous system tumors at least 3 months after the end of treatment (surgery and/or radiotherapy and/or chemotherapy) at the time of evaluation and "controls" as healthy children. Children's sleep quality was assessed with a questionnaire administered to parents (Child's Sleep Habits Questionnaire, CSHQ). A total score greater than 41 is suggestive for the presence of disturbed sleep. The risk of SD was estimated by the odds ratio (OR) and their 95% confidence intervals (95% CI) through logistic regression models. RESULTS: Twenty-nine cases and 87 controls (in a 1:3 model) were enrolled, for a total of 116 subjects. The prevalence of SD resulted of 82.8% among cases and 64.4% in controls. A statistically significant difference between the two groups (OR 2.65; 95% CI 0.92-7.65) was not reached. Analyzing singular disturbances, parasomnias and night awakenings showed a statistically significant difference between the two groups (OR 4.32; 95% CI 1.08-17.34). CONCLUSIONS: Our study revealed a trend toward SD in children with brain tumor when compared to healthy population. Hovewer, analyzing specific subtypes of SD some significant differences were obtained. A significant difference was obtained only for specific subtypes of SD. Further investigations could better define the real burden of SD.

Symptoms of anxiety and depression and family's quality of life in children and adolescents with epilepsy.

INTRODUCTION: We studied children and adolescents with epilepsy (CAWE) and their families to evaluate symptoms of anxiety and depression, quality of life (QoL), and their correlations with epilepsy characteristics. MATERIAL AND METHODS: The study included 326 (52.5% females) 8 to 18years old CAWE. Anxiety and depression were assessed with the "Self-administered psychiatric scales for children and adolescents" (SAFA), and family's QoL with the parents' report "Impact of Epilepsy on QoL" (IEQoL). RESULTS: The CAWE exhibiting abnormal (T≥70) scores were 8.0% in the anxiety scale, 9.2% in the depression scale, and 4.6% in both scales. Social anxiety was the predominant anxiety symptom, while irritable mood and desperation were the most frequent symptoms of depression. Depressive symptoms were associated with parents' complaint of higher worries about the child's condition and future and lower well-being of the family. Severity and duration of the epilepsy and polypharmacy were independent from abnormal scores of anxiety and depression, but were associated with parents' worries about the child's condition and family's well-being. CONCLUSIONS: Anxiety and depression in CAWE are independent from the characteristics of the disease but are correlated to the lower well-being of the family. A search of these emotional problems is recommended for better care of the patients and their families.

Patterns of care of brain tumor-related epilepsy. A cohort study done in Italian Epilepsy Center.

Epilepsy is the most common comorbidity in patients with brain tumors. STUDY AIMS: To define characteristics of brain tumor-related epilepsy (BTRE) patients and identify patterns of care. Nationwide, multicenter retrospective cohort study. Medical records of BTRE patients seen from 1/1/2010 to 12/31/2011, followed for at least one month were examined. Information included age, sex, tumor type/treatments, epilepsy characteristics, antiepileptic drugs (AEDs). Time to modify first AED due to inefficacy and/or toxicity was assessed with the Kaplan-Meier method and Cox proportional hazard models were used to identify predictors of treatment outcome. Enrolled were 808 patients (447 men, 361 women) from 26 epilepsy centers. Follow-up ranged 1 to 423 months (median 18 months). 732 patients underwent surgery, 483 chemotherapy (CT), 508 radiotherapy. All patients were treated with AEDs. Levetiracetam was the most common drug. 377 patients (46.7%) were still on first drug at end of follow-up, 338 (41.8%) needed treatment modifications (uncontrolled seizures, 229; side effects, 101; poor compliance, 22). Treatment discontinuation for lack of efficacy was associated with younger age, chemotherapy, and center with <20 cases. Treatment discontinuation for side effects was associated with female sex, enzyme-inducing drugs and center with > 20 cases. About one-half of patients with BTRE were on first AED at end of follow-up. Levetiracetam was the most common drug. A non enzyme-inducing AED was followed by a lower risk of drug discontinuation for SE.

Acute cerebellitis in children: an eleven year retrospective multicentric study in Italy.

BACKGROUND: Acute cerebellitis (AC) and acute cerebellar ataxia (ACA) are the principal causes of acute cerebellar dysfunction in childhood. Nevertheless. there is no accepted consensus regarding the best management of children with AC/ACA: the aim of the study is both to assess clinical, neuroimaging and electrophysiologic features of children with AC/ACA and to evaluate the correlation between clinical parameters, therapy and outcome. METHODS: A multicentric retrospective study was conducted on children ≤ 18 years old admitted to 12 Italian paediatric hospitals for AC/ACA from 01/01/2003 to 31/12/2013. A score based on both cerebellar and extracerebellar signs/symptoms was computed for each patient. One point was given for each sign/symptom reported. Severity was divided in three classes: low, moderate, severe. RESULTS: A total of 124 children were included in the study. Of these, 118 children received a final diagnosis of ACA and 6 of AC. The most characteristic finding of AC/ACA was a broad-based gait disturbance. Other common symptoms included balance disturbances, slurred speech, vomiting, headache and fever. Neurological sequelae were reported in 6 cases (5%) There was no correlation among symptoms, cerebrospinal fluid findings, clinical outcome. There was no correlation between clinical manifestations and clinical score on admission and length of hospital stay, sex, age and EEG findings with sequelae (P > 0.05). Children with pathological magnetic resonance imaging (MRI) or computed tomography (CT) had a higher probability of having clinical sequelae. Treatment was decided independently case by case. Patients with a higher clinical score on admission had a higher probability of receiving intravenous steroids. CONCLUSIONS: We confirmed the literature data about the benign course of AC/ACA in most cases but we also highlighted a considerable rate of patients with neurological sequelae (5%). Pathological MRI or CT findings at admission correlate to neurological sequelae. These findings suggest the indication to perform an instrumental evaluation in all patients with AC/ACA at admission to identify those at higher risk of neurological outcome. These patients may benefit from a more aggressive therapeutic strategy and should have a closer follow-up. Randomized controlled trials are needed to confirm these observations. The ultimate goal of these studies could be to develop a standardized protocol on AC/ACA. The MRI/CT data, associated with the clinical manifestations, may allow us to define the class risk of patients for a neurological outcome.

Association Between Migraine and Atopic Diseases in Childhood: A Potential Protective Role of Anti-Allergic Drugs.

BACKGROUND: Migraine is a common cause of headache in childhood. Several studies have investigated the association between migraine and atopic diseases, mostly in the adult population. OBJECTIVE: This study aimed to investigate this association in children. METHODS: A case-control study was conducted across 3 European tertiary care hospitals between June 2014 and August 2014. Cases (n = 229) were children aged 6-18 years consulting for a migraine episode. Controls in the same age range (n = 406) were consulting for a minor injury and did not have a history of recurrent headache. Logistic regression analyses tested the effect of atopic diseases and anti-allergic therapies on occurrence of migraine. RESULTS: Children with migraine were more likely to have persistent asthma compared to absence of asthma (odds ratio [OR]: 4.57, 95% confidence interval [CI]: 2.04-10.24) and less likely to have been treated by inhaled or nasal corticosteroid (OR: 0.34, 95% CI: 0.15-0.76) or antihistamine therapy (OR: 0.33, 95% CI: 0.18-0.60). The median number of monthly migraine episodes was higher in children with persistent asthma (3; interquartile [IQR]: 1-4; range: 0.5-10) compared to children with intermittent asthma (2; IQR: 1-3; range: 0.1-4) or non-asthmatic children (2; IQR: 1-3; range: 0.1-12) (P < .01). CONCLUSION: Persistent childhood asthma was associated with increased risk of migraine and higher frequency of migraine attacks. History of anti-asthmatic or anti-allergic therapies was associated with decreased risk of migraine in children and adolescents. The role of these therapies on the pathogenesis and occurrence of migraine needs to be further elucidated because of the huge potential impact in terms of public health.

Recovery position significantly associated with a reduced admission rate of children with loss of consciousness.

BACKGROUND: Loss of consciousness (LOC) is often seen in children. The response of caregivers to a child with LOC has been poorly investigated. Potential caregivers (parents, teachers) seem to have a poor knowledge of the recovery position (RP)-that is, the position into which an unconscious child should be placed in order to protect the airway. OBJECTIVES: To report the management and diagnoses of LOC in childhood, and to evaluate variables associated with an increased hospital admission rate. METHODS: We conducted a prospective cohort study of consecutive children aged between 0 and 18 years diagnosed with LOC at 11 paediatric emergency departments (PEDs) of 6 European countries. The enrolment period was 3 months. Data were obtained from parental interviews, PED reports and clinical examination. RESULTS: 553 children were enrolled. The most frequent final diagnoses causing LOC were seizures (n=278, 50.3%), and vasovagal syncope (n=124, 22.4%). Caregivers put the child in the RP in 145 cases (26.2%). The RP was independently associated with a significant decrease in the admission rate (aOR=0.28; 95% CI 0.17 to 0.48; p<0.0001). CONCLUSIONS: Our study demonstrates for the first time that the RP may reduce the admission rate of infants with LOC. Caregivers often perform inadequate manoeuvres when a child becomes unconscious. Campaigns aiming at increasing knowledge of the RP should be promoted.

Association between functional gastrointestinal disorders and migraine in children and adolescents: a case-control study.

BACKGROUND: Functional gastrointestinal disorders and migraine are both common causes of medical attention. We have previously shown an association between migraine and infant colic. In this case-control study, we aimed to establish whether there is an association between migraine and other functional gastrointestinal disorders in children and adolescents. METHODS: We included children and adolescents aged 6-17 years presenting to the emergency department of four tertiary hospitals in France and Italy. Patients diagnosed with either migraine or tension-type headache by the hospital's paediatric neurologist were enrolled as cases. Patients presenting to the emergency department with minor trauma and no history of recurrent headache were enrolled as controls. Investigators masked to a patient's group allocation diagnosed functional gastrointestinal disorders using the Rome III diagnostic criteria. Univariable and multivariable analyses were done to identify specific disorders and baseline factors associated with migraines and tension-type headache. FINDINGS: Between Nov 1, 2014, and Jan 31, 2015, we enrolled 648 controls and 424 cases (257 patients with migraine and 167 with tension-type headache). 83 (32%) children and adolescents in the migraine group were diagnosed with functional gastrointestinal disorders compared with 118 (18%) in the control group (p<0·0001). Multivariable logistic regression showed a significant association between migraine and three gastrointestinal disorders: functional dyspepsia (odds ratio 10·76, 95% CI 3·52-32·85; p<0·0001), irritable bowel syndrome (3·47, 1·81-6·62; p=0·0002), and abdominal migraine (5·87, 1·95-17·69; p=0·002). By contrast, there was an inverse association between migraine and functional constipation (0·34, 0·14-0·84, p=0·02). 41 (25%) participants with tension-type headache had functional gastrointestinal disorders, which did not significantly differ from the prevalence of these disorders in the control group (p=0·07); no significant association was noted between any functional gastrointestinal disease and tension-type headaches. INTERPRETATION: Three abdominal-pain-related functional gastrointestinal disorders were associated with migraine in children and adolescents. These findings are of value to the diagnosis and management of these common diseases. Future studies should investigate whether antimigraine drugs are of benefit in functional gastrointestinal disorders. FUNDING: None.

Recurrent seizures during acute acquired toxoplasmosis in an immunocompetent traveller returning from Africa.

INTRODUCTION: We report an unusual case of acute acquired toxoplasmosis (AAT) presenting as lymphadenopathy and recurrent seizures in an immunocompetent 15-year-old boy. MATERIALS AND METHODS: The patient reported an 18-day vacation to Africa (Ethiopia), 39 days prior to the first seizure. Electroencephalogram (EEG) showed sporadic single-spike or sharp-wave paroxysms and the magnetic resonance imaging (RMI) of the brain was negative. The serology for T. gondii was compatible with an acute infection defined as positive for both toxoplasma-specific IgG and IgM and a low avidity (6 %), confirmed by a reference laboratory. The patient reported other two episodes of seizures, occurring 7 days apart. He was treated with pyrimethamine plus sulfadiazine and leucovorin for 4 weeks, with an improvement of lymphadenitis and normalization of EEG. After 5 months, new seizures were reported and a diagnosis of epilepsy was done. Toxoplasma polymerase chain reaction (PCR) of cerebrospinal fluid (CSF) and blood were negative. A treatment with valproic acid was started, obtaining control of the neurological disease. CONCLUSION: Awareness of this neurologic manifestation by clinicians is required, also in immunocompetent patients. The relationship between toxoplasmosis and recurrent seizure needs to be investigated by new studies.

Ultrasound detection of pneumonia in febrile children with respiratory distress: a prospective study.

To analyse the usefulness of bedside lung ultrasound (LUS) in detecting lung consolidation in a paediatric emergency room (ER) setting, febrile children seen at our ER from 2008 to 2012 with a moderate to severe respiratory distress underwent LUS, chest X-ray (CXR) and laboratory investigations. At first ER assessment, LUS identified a lung consolidation in 207 patients of 222 children enrolled, with a liver-like appearance in 75 (36.2%) and an associated pleural effusion in 36.7% of cases. CXR proved positive in 197 cases, showing a parenchymal consolidation (68.5%) or a focal ground-glass opacity (31.4%). LUS liver-like consolidation was significantly associated with longer duration of fever (p = 0.002), higher neutrophil counts and C-reactive protein (CRP) values (p = 0.015 and p < 0.0001, respectively), and with the discovery of a homogeneous and dense parenchymal consolidation on CXR (p < 0.0001). CONCLUSION: LUS can be adopted by the clinician as a non-invasive bedside tool to expand the physical evaluation of febrile children with respiratory distress. In our study, LUS results appeared not only as reliable as CXR in detecting lung consolidations but also consistent with clinical and laboratory data. WHAT IS KNOWN: The diagnosis of pneumonia is mainly based on physical examination plus radiologic and laboratory evaluation when needed. Although lung ultrasound (LUS) has shown high sensitivity in detecting several pleuropulmonary diseases in adults, its role in the work-up of pneumonia in children is not yet widely recognized. WHAT IS NEW: LUS is confirmed to be a reliable imaging technique for the diagnostic work-up of febrile children with respiratory distress, consistent not only with CXR results as previously reported by others but also with clinical and laboratory data. In the hands of trained clinicians, it may represent a valuable supplemental bedside tool for a rapid evaluation in such circumstances.

Characterization of human disease phenotypes associated with mutations in TREX1, RNASEH2A, RNASEH2B, RNASEH2C, SAMHD1, ADAR, and IFIH1.

Aicardi-Goutières syndrome is an inflammatory disease occurring due to mutations in any of TREX1, RNASEH2A, RNASEH2B, RNASEH2C, SAMHD1, ADAR or IFIH1. We report on 374 patients from 299 families with mutations in these seven genes. Most patients conformed to one of two fairly stereotyped clinical profiles; either exhibiting an in utero disease-onset (74 patients; 22.8% of all patients where data were available), or a post-natal presentation, usually within the first year of life (223 patients; 68.6%), characterized by a sub-acute encephalopathy and a loss of previously acquired skills. Other clinically distinct phenotypes were also observed; particularly, bilateral striatal necrosis (13 patients; 3.6%) and non-syndromic spastic paraparesis (12 patients; 3.4%). We recorded 69 deaths (19.3% of patients with follow-up data). Of 285 patients for whom data were available, 210 (73.7%) were profoundly disabled, with no useful motor, speech and intellectual function. Chilblains, glaucoma, hypothyroidism, cardiomyopathy, intracerebral vasculitis, peripheral neuropathy, bowel inflammation and systemic lupus erythematosus were seen frequently enough to be confirmed as real associations with the Aicardi-Goutieres syndrome phenotype. We observed a robust relationship between mutations in all seven genes with increased type I interferon activity in cerebrospinal fluid and serum, and the increased expression of interferon-stimulated gene transcripts in peripheral blood. We recorded a positive correlation between the level of cerebrospinal fluid interferon activity assayed within one year of disease presentation and the degree of subsequent disability. Interferon-stimulated gene transcripts remained high in most patients, indicating an ongoing disease process. On the basis of substantial morbidity and mortality, our data highlight the urgent need to define coherent treatment strategies for the phenotypes associated with mutations in the Aicardi-Goutières syndrome-related genes. Our findings also make it clear that a window of therapeutic opportunity exists relevant to the majority of affected patients and indicate that the assessment of type I interferon activity might serve as a useful biomarker in future clinical trials.

Pharmacokinetic/pharmacodynamic evaluation of linezolid in hospitalized paediatric patients: a step toward dose optimization by means of therapeutic drug monitoring and Monte Carlo simulation.

OBJECTIVES: To report on linezolid exposure in a paediatric population who routinely underwent therapeutic drug monitoring (TDM) for dosage optimization and to assess the factors affecting interpatient variability. METHODS: We performed a retrospective study of patients whose plasma C(min) and Cmax levels were measured during linezolid treatment. Adequate exposure was defined as a C(min) of 2-7 mg/L and/or an estimated AUC24 of 160-300 mg · h/L. Patients were divided into two subgroups (Group 1, 2-11 years; Group 2, 12-18 years). Monte Carlo simulation was performed to investigate whether or not the currently recommended dosages might enable a high probability of target attainment (PTA) of two thresholds for linezolid efficacy (AUC24/MIC ≥ 80 or ≥ 100). Data on demographic characteristics, disease, microbiology and haematochemical parameters and outcomes were collected. RESULTS: A total of 23 patients were included. Standard dosages were suboptimal in 50.0% and 44.4% of patients in Group 1 and Group 2, respectively. Among those who underwent multiple instances of TDM, the dosages were increased in 33.3% of cases in both groups, and decreased in 6.6% and 9.5% of cases in Group 1 and Group 2, respectively. Co-treatment with phenobarbital, proton pump inhibitors and amiodarone accounted for most of the variability in C(min) (adjusted R(2) of 0.692). Simulations showed a PTA of ≥ 90% with the current dosing regimens in both groups only for pathogens with an MIC ≤ 1 mg/L. CONCLUSIONS: Higher dosages of linezolid may be needed, especially in Group 1 when in the presence of pathogens with an MIC >1 mg/L. The role of TDM should be encouraged for optimization of linezolid exposure in the paediatric setting in the presence of infections caused by pathogens with borderline susceptibility and/or for patients co-treated with drugs that may alter linezolid exposure.