Neurodevelopmental outcome in children with congenital cytomegalovirus infection: A prospective multicenter cohort study.

BACKGROUND: Congenital cytomegalovirus infection (cCMV) is the most common congenital infection worldwide and is a major cause of neurodevelopmental impairment in children. At this point there are insufficient data on neurodevelopmental outcome of children with cCMV, both symptomatic and asymptomatic. AIM: This study aimed to describe the neurodevelopmental outcome in a large prospective cohort of children with cCMV. METHODS: All children with cCMV, included in the Flemish cCMV register, were eligible for this study. Data on neurodevelopmental outcome was available in 753 children. Data on neuromotor, cognitive, behavioral, audiological and ophthalmological outcome were analyzed. RESULTS: Neurodevelopmental outcome was normal in 530/753 (70,4 %) at any age of last follow-up. Mild, moderate and severe neurodevelopmental impairment was found in 128/753 (16,9 %), 56/753 (7,4 %) and 39/753 (5,2 %), respectively. Adverse outcome is found both in the symptomatic and asymptomatic children (53,5 % versus 17,8 %). Autism spectrum disorder (ASD) was diagnosed more often than in the general population in Flanders (2,5 % versus 0,7 %). Speech and language impairment was found in 2 %, even in absence of hearing loss. CONCLUSION: Both symptomatic and asymptomatic cCMV children are at risk of sequelae, with higher risk in case of first trimester infection. During follow-up of this population, special attention should be given to the audiological follow-up, the presence of hypotonia at young age, the possible higher risk of ASD and the risk of speech and language impairment even in absence of hearing loss. Our results emphasize the need for multidisciplinary neurodevelopmental follow-up of all cCMV infected children.

White matter microstructural differences in children and genetic risk for multiple sclerosis: A population-based study.

BACKGROUND: MS patients show abnormalities in white matter (WM) on brain imaging, with heterogeneity in the location of WM lesions. The "pothole" method can be applied to diffusion-weighted images to identify spatially distinct clusters of divergent brain WM microstructure. OBJECTIVE: To investigate the association between genetic risk for MS and spatially independent clusters of decreased or increased fractional anisotropy (FA) in the brain. In addition, we studied sex- and age-related differences. METHODS: 3 Tesla diffusion tensor imaging (DTI) data were collected in 8- to 12-year-old children from a population-based study. Global and tract-based potholes (lower FA clusters) and molehills (higher FA clusters) were quantified in 3047 participants with usable DTI data. A polygenic risk score (PRS) for MS was calculated in genotyped individuals (n = 1087) and linear regression analyses assessed the relationship between the PRS and the number of potholes and molehills, correcting for multiple testing using the False Discovery Rate. RESULTS: The number of molehills increased with age, potholes decreased with age, and fewer potholes were observed in girls during typical development. The MS-PRS was positively associated with the number of molehills (ß = 0.9, SE = 0.29, p = 0.002). Molehills were found more often in the corpus callosum (ß = 0.3, SE = 0.09, p = 0.0003). CONCLUSION: Genetic risk for MS is associated with spatially distinct clusters of increased FA during childhood brain development.

Stability and Change of Psychopathology Symptoms Throughout Childhood and Adolescence.

Assessing stability and change of children's psychopathology symptoms can help elucidate whether specific behaviors are transient developmental variations or indicate persistent psychopathology. This study included 6930 children across early childhood (T1), late childhood (T2) and early adolescence (T3), from the general population. Latent profile analysis identified psychopathology subgroups and latent transition analysis quantified the probability that children remained within, or transitioned across psychopathology subgroups. We identified four psychopathology subgroups; no problems (T1: 85.9%, T2: 79.0%, T3: 78.0%), internalizing (T1: 5.1%, T2: 9.2%, T3: 9.0%), externalizing (T1: 7.3%, T2: 8.3%, T3: 10.2%) and the dysregulation profile (DP) (T1: 1.7%, T2: 3.5%, T3: 2.8%). From T1 to T2, 44.7% of the children remained in the DP. Between T2 and T3, 33.6% remained in the DP; however, 91.4% were classified in one of the psychopathology subgroups. Our findings suggest that for many children, internalizing or externalizing symptoms encompass a transient phase within development. Contrary, the DP resembles a severe at-risk state in which the predictive value for being in one of the psychopathology subgroups increases over time.

Effector T Helper Cells Are Selectively Controlled During Pregnancy and Related to a Postpartum Relapse in Multiple Sclerosis.

Background: Multiple sclerosis (MS) patients are protected from relapses during pregnancy and have an increased relapse risk after delivery. It is unknown how pregnancy controls disease-contributing CD4+ T helper (Th) cells and whether this differs in MS patients who experience a postpartum relapse. Here, we studied the effector phenotype of Th cells in relation to pregnancy and postpartum relapse occurrence in MS. Methods: Memory skewing and activation of effector Th subsets were analyzed in paired third trimester and postpartum blood of 19 MS patients with and without a postpartum relapse and 12 healthy controls. Ex vivo results were associated with circulating levels of pregnancy-induced hormones and mirrored in vitro by exposing proliferating Th cells to corresponding serum samples. Results: Based on HSNE-guided analyses, we found that effector memory proportions of Th cells were increased in postpartum vs. third trimester samples from MS patients without a postpartum relapse. This was not seen for relapsing patients or healthy controls. CXCR3 was upregulated on postpartum memory Th cells, except for relapsing patients. These changes were verified by adding sera from the same individuals to proliferating Th cells, but did not associate with third trimester cortisol, estradiol or progesterone levels. For relapsing patients, activated memory Th cells of both third trimester and postpartum samples produced higher levels of pro-inflammatory cytokines. Conclusion: Effector Th cells are differentially regulated during pregnancy in MS patients, likely via serum-related factors beyond the studied hormones. The pro-inflammatory state of memory Th cells during pregnancy may predict a postpartum relapse.

Prevalence of radiologically isolated syndrome in a pediatric population-based cohort: A longitudinal description of a rare diagnosis.

BACKGROUND: Radiologically isolated syndrome (RIS) is typified by multiple sclerosis (MS)-like lesions on imaging, without clinical MS symptoms. The prevalence of pediatric RIS is largely unknown. OBJECTIVE: The objective of the study is to provide an estimated RIS prevalence in a population-based cohort of children. METHODS: We used data from the Generation R study to identify the childhood RIS prevalence. RESULTS: In 5238 participants, only one RIS case was identified (prevalence: 0.02%; 95% confidence interval (CI): 0.00-0.11). During a 62-month follow-up, imaging examinations showed accrual of new focal demyelinating lesions; however, no clinical MS symptoms occurred. CONCLUSIONS: This study shows that the occurrence of RIS in children from the general population is rare.

Polygenic Multiple Sclerosis Risk and Population-Based Childhood Brain Imaging.

OBJECTIVE: Multiple sclerosis (MS) is a neurological disease with a substantial genetic component and immune-mediated neurodegeneration. Patients with MS show structural brain differences relative to individuals without MS, including smaller regional volumes and alterations in white matter (WM) microstructure. Whether genetic risk for MS is associated with brain structure during early neurodevelopment remains unclear. In this study, we explore the association between MS polygenic risk scores (PRS) and brain imaging outcomes from a large, population-based pediatric sample to gain insight into the underlying neurobiology of MS. METHODS: We included 8- to 12-year-old genotyped participants from the Generation R Study in whom T1-weighted volumetric (n = 1,136) and/or diffusion tensor imaging (n = 1,088) had been collected. PRS for MS were calculated based on a large genome-wide association study of MS (n = 41,505) and were regressed on regional volumes, global and tract-specific fractional anisotropy (FA), and global mean diffusivity using linear regression. RESULTS: No associations were observed for the regional volumes. We observed a positive association between the MS PRS and global FA (ß = 0.098, standard error [SE] = 0.030, p = 1.08 × 10-3 ). Tract-specific analyses showed higher FA and lower radial diffusivity in several tracts. We replicated our findings in an independent sample of children (n = 186) who were scanned in an earlier phase (global FA; ß = 0.189, SE = 0.072, p = 9.40 × 10-3 ). INTERPRETATION: This is the first study to show that greater genetic predisposition for MS is associated with higher global brain WM FA at an early age in the general population. Our results suggest a preadolescent time window within neurodevelopment in which MS risk variants act upon the brain. ANN NEUROL 2020;87:774-787.

The clinical spectrum and incidence of anti-MOG-associated acquired demyelinating syndromes in children and adults.

OBJECTIVES: The aim of this study was to assess the Dutch nationwide incidence of myelin oligodendrocyte glycoprotein (MOG)-IgG-associated acquired demyelinating syndromes (ADS) and to describe the clinical and serological characteristics of these patients. METHODS: All serum samples for routine diagnostics from February 2014 to December 2017 were sent to the single central reference laboratory for the full-length MOG-IgG cell-based assay (CBA) in the Netherlands. Clinical data from patients known in our National ADS centre were available. RESULTS: A total of 1414 samples of 1277 patients were received; of these, 92 patients (7%) were MOG-IgG-seropositive. The mean incidence was 0.16/100,000 people, with higher seropositivity in children (0.31/100,000) than in adults (0.13/100,000). In MOG-IgG-positive patients at the National ADS centre (61/92, 66%), the most common presenting phenotype is acute disseminated encephalomyelitis (ADEM, 56%) in children and optic neuritis (ON, 44%) in adults. Relapsing disease occurred in 9/34 (26%) children and 11/27 (41%) adults during median follow-up of 27.5 months. Patients were tested MOG-IgG-positive >200 months after the initial attack, suggesting an extended time to first relapse (TTFR). Longitudinal analysis of MOG-IgG (25/61, 41%) showed that 67% of the monophasic patients remain seropositive and 60% in relapsing patients. Majority of seronegative patients had no relapses (89%). CONCLUSION: This nationwide study shows that the overall incidence of MOG-IgG-seropositive disorders is 0.16 per 100,000 people. The distribution over the clinical phenotypes differs between adults and children. Seropositivity can be maintained over years even without clinical activity, while seronegative patients generally had no relapses.

Real-world validation of the 2017 McDonald criteria for pediatric MS.

Objective: To compare the diagnostic accuracy of the McDonald 2017 vs the McDonald 2010 criteria to predict a second attack of MS (clinically definite MS [CDMS]) at the first attack of acquired demyelinating syndromes (ADS). Methods: One hundred sixty-four children (aged <18 years) with an incident attack of ADS were included in a prospective multicenter study between June 2006 and December 2016. Brain (and spinal if available) MRI was performed ≤3 months after symptom onset. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were compared at baseline between the 2010 and 2017 criteria. Results: Among the 164 patients, 110 patients (67%) presented without encephalopathy (ADS-, female 63%; median age 14.8 years, IQR 11.3-16.1years) and 54 (33%) with encephalopathy (acute disseminated encephalomyelitis [ADEM], female 52%; median age 4.0 years, IQR 2.6-6.1 years). Of the 110 ADS- patients, 52 (47%) were diagnosed with CDMS within a median follow-up of 4.5 years (IQR 2.6-6.7 years). The sensitivity was higher for the 2017 criteria than for the 2010 criteria (83%; 95% CI 67-92, vs 49%; 95% CI 33-65; p < 0.001), but the specificity was lower (73%; 95% CI 59-84 vs 87%; 95% CI 74-94, p = 0.02). At baseline, 48 patients fulfilled the 2017 criteria compared with 27 patients when using the 2010 criteria. The results for children aged <12 years without encephalopathy were similar. In patients with ADEM, 8% fulfilled the 2010 criteria and 10% the 2017 criteria at baseline but no patient fulfilled the criteria for CDMS. Conclusions: The McDonald 2017 criteria are more sensitive than the McDonald 2010 criteria for predicting CDMS at baseline. These criteria can also be applied in children aged <12 years without encephalopathy but not in children with ADEM. Classification of evidence: This study provides Class II evidence that in children with ADS, the 2017 McDonald criteria are more sensitive but less specific than the 2010 McDonald criteria for predicting CDMS.

Brain-Tumor-Regenerating 3D Scaffold-Based Primary Xenograft Models for Glioma Stem Cell Targeted Drug Screening.

Glioma stem cells (GSC) present a critical therapeutic challenge for glioblastoma multiforme (GBM). Drug screening against GSC demands development of novel in vitro and in vivo platforms that can mimic brain microenvironment and support GSC maintenance and tumorigenesis. Here, we report, a 3-dimensionel (3D) biomimetic macro-porous scaffold developed by incorporating hyaluronic acid, porcine brain extra cellular matrix (ECM) and growth factors that facilitates regeneration of GBM from primary GSCs, ex vivo and in vivo. After characterizing with human and rat GBM cell lines and neurospheres, human GSCs expressing Notch1, Sox-2, Nestin, and CD133 biomarkers were isolated from GBM patients, cultured in the 3D scaffold, and implanted subcutaneously in nude mice to develop patient derived xenograft (PDX) models. Aggressive growth pattern of PDX with formation of intratumoral vascularization was monitored by magnetic resonance imaging (MRI). Histopathological and phenotypial features of the original tumors were retained in the PDX models. We used this regenerated GBM platform to screen novel siRNA nanotherapeutics targeting Notch, Sox-2, FAK signaling for its ability to inhibit the tumorigenic potential of GSCs. Current clinical drug, Temozolomide and an anticancer phytochemical, nanocurcumin, were used as controls. The siRNA nanoparticles showed excellent efficacy in inhibiting tumorigenesis by GSCs in vivo. Our study suggests that the brain-ECM mimicking scaffold can regenerate primary gliomas from GSCs in vitro and in vivo, and the same can be used as an effective platform for screening drugs against glioma stem cells.

Incidence and outcome of acquired demyelinating syndromes in Dutch children: update of a nationwide and prospective study.

INTRODUCTION: Acquired demyelinating syndromes (ADS) are immune-mediated demyelinating disorders of the central nervous system in children. A nationwide, multicentre and prospective cohort study was initiated in the Netherlands in 2006, with a reported ADS incidence of 0.66/100,000 per year and MS incidence of 0.15/100,000 per year in the period between 2007 and 2010. In this study, we provide an update on the incidence and the long-term follow-up of ADS in the Netherlands. METHODS: Children < 18 years with a first attack of demyelination were included consecutively from January 2006 to December 2016. Diagnoses were based on the International Paediatric MS study group consensus criteria. Outcome data were collected by neurological and neuropsychological assessments, and telephone call assessments. RESULTS: Between 2011 and 2016, 55/165 of the ADS patients were diagnosed with MS (33%). This resulted in an increased ADS and MS incidence of 0.80/100,000 per year and 0.26/100,000 per year, respectively. Since 2006 a total of 243 ADS patients have been included. During follow-up (median 55 months, IQR 28-84), 137 patients were diagnosed with monophasic disease (56%), 89 with MS (37%) and 17 with multiphasic disease other than MS (7%). At least one form of residual deficit including cognitive impairment was observed in 69% of all ADS patients, even in monophasic ADS. An Expanded Disability Status Scale score of ≥ 5.5 was reached in 3/89 MS patients (3%). CONCLUSION: The reported incidence of ADS in Dutch children has increased since 2010. Residual deficits are common in this group, even in monophasic patients. Therefore, long-term follow-up in ADS patients is warranted.

Routine abdominal ultrasonography has limited value in the care for patients with indolent systemic mastocytosis.

OBJECTIVES: Systemic mastocytosis (SM) is a myeloproliferative disease characterized by the accumulation of aberrant mast cells. Since advanced subtypes of SM can lead to organ dysfunction and shortened survival, timely recognition of progressive disease is important for the adequate treatment of SM patients. METHODS: Here, we report the results of our cohort study on the value of routine abdominal ultrasonography for the detection of progression of indolent systemic mastocytosis (ISM). RESULTS: We included 88 patients with ISM, of whom 9 developed new hepatosplenomegaly during follow-up. In this group, the median serum tryptase level increased by 11.60 µg/l, compared with a decrease of -0.20 µg/l in the 79 patients with unchanged ultrasonography results (p = 0.016). A change in liver and/or spleen size never led to a change in clinical classification, nor management. DISCUSSION: Based on the finding that a change in ultrasonography findings did not correlate to disease progression in general, it appears that isolated hepatosplenomegaly does not have prognostic implications in patients with ISM. CONCLUSIONS: Routine abdominal ultrasonography is redundant in the follow-up of patients with ISM. A combination of physical examination with serum tryptase levels can be used to screen for hepatosplenomegaly.

Osteoporosis markers on low-dose lung cancer screening chest computed tomography scans predict all-cause mortality.

OBJECTIVES: Further survival benefits may be gained from low-dose chest computed tomography (CT) by assessing vertebral fractures and bone density. We sought to assess the association between CT-measured vertebral fractures and bone density with all-cause mortality in lung cancer screening participants. METHODS: Following a case-cohort design, lung cancer screening trial participants (N = 3,673) who died (N = 196) during a median follow-up of 6 years (inter-quartile range: 5.7-6.3) were identified and added to a random sample of N = 383 from the trial. We assessed vertebral fractures using Genant's semiquantative method on sagittal reconstructions and measured bone density (Hounsfield Units (HU)) in vertebrae. Cox proportional hazards modelling was used to determine if vertebral fractures or bone density were independently predictive of mortality. RESULTS: The prevalence of vertebral fractures was 35% (95% confidence interval 30-40%) among survivors and 51% (44-58%) amongst cases. After adjusting for age, gender, smoking status, pack years smoked, coronary and aortic calcium volume and pulmonary emphysema, the adjusted hazard ratio (HR) for vertebral fracture was 2.04 (1.43-2.92). For each 10 HU decline in trabecular bone density, the adjusted HR was 1.08 (1.02-1.15). CONCLUSIONS: Vertebral fractures and bone density are independently associated with all-cause mortality. KEY POINTS: • Lung cancer screening chest computed tomography contains additional, potentially useful information. • Vertebral fractures and bone density are independently predictive of mortality. • This finding has implications for screening and management decisions.

Thiopurine metabolism and identification of the thiopurine metabolites transported by MRP4 and MRP5 overexpressed in human embryonic kidney cells.

Mercaptopurines have been used as anticancer agents for more than 40 years, and most acute lymphoblastic leukemias are treated with 6-mercaptopurine (6MP) or 6-thioguanine (TG). Overexpression of the two related multidrug resistance proteins MRP4 and MRP5 has been shown to confer some resistance against mercaptopurines, which has been attributed to extrusion of mercaptopurine metabolites by these transporters. We have analyzed the mercaptopurine metabolites formed in human embryonic kidney cells and determined which metabolites are extruded by MRP4 and MRP5. Incubation with 6MP led to the formation of thioinosine and thioxanthosine metabolites and we found that thio-IMP was transported by both MRP4 and MRP5; MRP5 showed the highest transport rate. In contrast, only MRP5 transported thioxanthosine monophosphate (tXMP). During incubation with TG, the monophosphorylated form of thioguanosine was transported by both MRP4 and MRP5; the highest transport rate was for MRP4. Similarly, only 6-methyl-thio-IMP was formed during incubation with 6-methyl mercaptopurine riboside. This compound was a substrate for both MRP4 and MRP5; MRP4 showed the highest transport rate. Our results show that all major thiopurine monophosphates important in the efficacy of mercaptopurine treatment are transported by MRP4 and MRP5, although the substrate specificity of the two transporters differs in detail.

DNA damage recognition and repair pathway coordination revealed by the structural biochemistry of DNA repair enzymes.

Cells have evolved distinct mechanisms for both preventing and removing mutagenic and lethal DNA damage. Structural and biochemical characterization of key enzymes that function in DNA repair pathways are illuminating the biological and chemical mechanisms that govern initial lesion detection, recognition, and excision repair of damaged DNA. These results are beginning to reveal a higher level of DNA repair coordination that ensures the faithful repair of damaged DNA. Enzyme-induced DNA distortions allow for the specific recognition of distinct extrahelical lesions, as well as tight binding to cleaved products, which has implications for the ordered transfer of unstable DNA repair intermediates between enzymes during base excision repair.

Reduced hepatic uptake and intestinal excretion of organic cations in mice with a targeted disruption of the organic cation transporter 1 (Oct1 [Slc22a1]) gene.

The polyspecific organic cation transporter 1 (OCT1 [SLC22A1]) mediates facilitated transport of small (hydrophilic) organic cations. OCT1 is localized at the basolateral membrane of epithelial cells in the liver, kidney, and intestine and could therefore be involved in the elimination of endogenous amines and xenobiotics via these organs. To investigate the pharmacologic and physiologic role of this transport protein, we generated Oct1 knockout (Oct1(-/-)) mice. Oct1(-/-) mice appeared to be viable, healthy, and fertile and displayed no obvious phenotypic abnormalities. The role of Oct1 in the pharmacology of substrate drugs was studied by comparing the distribution and excretion of the model substrate tetraethylammonium (TEA) after intravenous administration to wild-type and Oct1(-/-) mice. In Oct1(-/-) mice, accumulation of TEA in liver was four to sixfold lower than in wild-type mice, whereas direct intestinal excretion of TEA was reduced about twofold. Excretion of TEA into urine over 1 h was 53% of the dose in wild-type mice, compared to 80% in knockout mice, probably because in Oct1(-/-) mice less TEA accumulates in the liver and thus more is available for rapid excretion by the kidney. In addition, we found that absence of Oct1 leads to decreased liver accumulation of the anticancer drug metaiodobenzylguanidine and the neurotoxin 1-methyl-4-phenylpyridium. In conclusion, our data show that Oct1 plays an important role in the uptake of organic cations into the liver and in their direct excretion into the lumen of the small intestine.

Specific detection of multidrug resistance proteins MRP1, MRP2, MRP3, MRP5, and MDR3 P-glycoprotein with a panel of monoclonal antibodies.

Tumor cells may display a multidrug resistance phenotype by overexpression of ATP binding cassette transporter genes such as multidrug resistance (MDR) 1 P-glycoprotein (P-gp) or the multidrug resistance protein 1 (MRP1). MDR3 P-gp is a close homologue of MDR1 P-gp, but its role in MDR is probably minor and remains to be established. The MRP1 protein belongs to a family of at least six members. Three of these, i.e., MRP1, MRP2, and MRP3, can transport MDR drugs and could be involved in MDR. The substrate specificity of the other family members remains to be defined. Specific monoclonal antibodies are required for wide-scale studies on the putative contribution of these closely related transporter proteins to MDR. In this report, we describe the extensive characterization of a panel of monoclonal antibodies (Mabs) detecting several MDR-related transporter proteins in both human and animal tissues. The panel consists of P3II-1 and P3II-26 for MDR3 P-gp; MRPr1, MRPm6, MRPm5, and MIB6 for MRP1; M2I-4, M2II-12, M2III-5 and M2III-6 for MRP2; M3II-9 and M3II-21 for MRP3; and M5I-1 and M5II-54 for MRP5. All Mabs in the panel appeared to be fully specific for their cognate antigens, both in Western blots and cytospin preparations, as revealed by lack of cross-reactivity with any of the other family members. Indeed, all Mabs were very effective in detecting their respective antigens in cytospins of transfected cell lines, whereas in flow cytometric and immunohistochemical analyses, distinct differences in reactivity and suitability were noted. These Mabs should become valuable tools in studying the physiological functions of these transporter proteins, in screening procedures for the absence of these proteins in hereditary metabolic (liver) diseases, and in studying the possible contributions of these molecules to MDR in cancer patients.