Taenia martis Neurocysticercosis-Like Lesion in Child, Associated with Local Source, the Netherlands.

A neurocysticercosis-like lesion in an 11-year-old boy in the Netherlands was determined to be caused by the zoonotic Taenia martis tapeworm. Subsequent testing revealed that 15% of wild martens tested in that region were infected with T. martis tapeworms with 100% genetic similarity; thus, the infection source was most likely local.

Evaluation of Dosing Guidelines for Gentamicin in Neonates and Children.

Although aminoglycosides are frequently prescribed to neonates and children, the ability to reach effective and safe target concentrations with the currently used dosing regimens remains unclear. This study aims to evaluate the target attainment of the currently used dosing regimens for gentamicin in neonates and children. We conducted a retrospective single-center cohort study in neonates and children receiving gentamicin between January 2019 and July 2022, in the Beatrix Children's Hospital. The first gentamicin concentration used for therapeutic drug monitoring was collected for each patient, in conjunction with information on dosing and clinical status. Target trough concentrations were ≤1 mg/L for neonates and ≤0.5 mg/L for children. Target peak concentrations were 8-12 mg/L for neonates and 15-20 mg/L for children. In total, 658 patients were included (335 neonates and 323 children). Trough concentrations were outside the target range in 46.2% and 9.9% of neonates and children, respectively. Peak concentrations were outside the target range in 46.0% and 68.7% of neonates and children, respectively. In children, higher creatinine concentrations were associated with higher gentamicin trough concentrations. This study corroborates earlier observational studies showing that, with a standard dose, drug concentration targets were met in only approximately 50% of the cases. Our findings show that additional parameters are needed to improve target attainment.

Adoption is not associated with immunological and virological outcomes in children with perinatally acquired HIV infection in the Netherlands.

OBJECTIVES: To provide an overview of the demographics, treatment characteristics and long-term outcomes of children with perinatal HIV-1 infection (PHIV) living in the Netherlands (NL) and to specifically investigate whether outcomes differ by children's adoption status. DESIGN: A prospective population-based open cohort including children with PHIV in NL. METHODS: We included children with PHIV who had entered HIV care in NL since 2007, in view of a sharp increase in the number of adopted children with PHIV since that year. We compared the proportion with virologic suppression and CD4+T-cell count over time between the following groups of children with PHIV: adopted and born outside NL, non-adopted born in NL, and non-adopted born outside NL, using generalized estimating equations and linear mixed effects models, respectively. To account for the variation in cohort inclusion, we analyzed data of children exposed to at least one year of antiretroviral therapy (ART). RESULTS: We included 148 children (827.5 person-years of follow-up, 72% adopted, age at start care in NL 2.4 (0.5-5.3)). Under-18 mortality was zero. Over the years, a boosted PI-based regimen was most often prescribed. The use of integrase inhibitors increased since 2015. Non-adopted children born in NL were less likely to achieve virological suppression compared to adopted children (OR 0.66, 95%CI 0.51-0.86, p = 0.001), which disappeared after excluding one child with suspected treatment nonadherence (OR 0.85, 95%CI 0.57-1.25, p = 0.400). CD4+T-cell Z-score trajectories were not significantly different between groups. CONCLUSIONS: Despite considerable and increasing diversity of the population of children with PHIV in NL, geographical origin and adoption status do not seem to pose important challenges in achieving good immunological and virological outcomes.

Subtherapeutic Exposure of Ganciclovir in Children Despite Appropriate Dosing: A Short Communication.

ABSTRACT: Therapeutic drug monitoring (TDM) results for ganciclovir in 12 different treatment episodes showed large intraindividual and interindividual variabilities in the trough concentration and area under the 24-hour concentration-time curve (AUC24). Despite adequate valganciclovir dosing, subtherapeutic concentrations were found in 30% of the treatment episodes. A decrease in viral load was observed regardless of subtherapeutic exposure. These findings show the need for target concentration evaluation and assessment of the applicability of ganciclovir TDM in children.

Indeterminate pediatric acute liver failure: Clinical characteristics of a temporal cluster of five children in the Netherlands in the spring of 2022.

There is increasing global concern of severe acute hepatitis of unknown etiology in young children. In early 2022, our center for liver transplantation in the Netherlands treated five children who presented in short succession with indeterminate acute liver failure. Four children underwent liver transplantation, one spontaneously recovered. Here we delineate the clinical course and comprehensive diagnostic workup of these patients. Three of five patients showed a gradual decline of liver synthetic function and had mild neurological symptoms. Their clinical and histological findings were consistent with hepatitis. These three patients all had a past SARS-CoV-2 infection and two of them were positive for adenovirus DNA. The other two patients presented with advanced liver failure and encephalopathy and underwent dialysis as a bridge to transplantation. One of these children spontaneously recovered. We discuss this cluster of patients in the context of the currently elevated incidence of severe acute hepatitis in children.

Tuberculosis Disease in Children and Adolescents on Therapy With Antitumor Necrosis Factor-ɑ Agents: A Collaborative, Multicenter Paediatric Tuberculosis Network European Trials Group (ptbnet) Study.

BACKGROUND: In adults, anti-tumor necrosis factor-α (TNF-α) therapy is associated with progression of latent tuberculosis (TB) infection (LTBI) to TB disease, but pediatric data are limited. METHODS: Retrospective multicenter study within the Paediatric Tuberculosis Network European Trials Group, capturing patients <18 years who developed TB disease during anti-TNF-α therapy. RESULTS: Sixty-six tertiary healthcare institutions providing care for children with TB participated. Nineteen cases were identified: Crohn's disease (n = 8; 42%) and juvenile idiopathic arthritis (n = 6; 32%) were the commonest underlying conditions. Immune-based TB screening (tuberculin skin test and/or interferon-γ release assay) was performed in 15 patients before commencing anti-TNF-α therapy but only identified 1 LTBI case; 13 patients were already receiving immunosuppressants at the time of screening. The median interval between starting anti-TNF-α therapy and TB diagnosis was 13.1 (IQR, 7.1-20.3) months. All cases presented with severe disease, predominantly miliary TB (n = 14; 78%). One case was diagnosed postmortem. TB was microbiologically confirmed in 15 cases (79%). The median duration of anti-TB treatment was 50 (IQR, 46-66) weeks. Five of 15 (33%) cases who had completed TB treatment had long-term sequelae. CONCLUSIONS: LTBI screening is frequently false-negative in this patient population, likely due to immunosuppressants impairing test performance. Therefore, patients with immune-mediated diseases should be screened for LTBI at the point of diagnosis, before commencing immunosuppressive medication. Children on anti-TNF-α therapy are prone to severe TB disease and significant long-term morbidity. Those observations underscore the need for robust LTBI screening programs in this high-risk patient population, even in low-TB-prevalence settings.

Upsurge of Enterovirus D68, the Netherlands, 2016.

In June and July 2016, we identified 8 adults and 17 children with respiratory enterovirus D68 infections. Thirteen children required intensive care unit admission because of respiratory insufficiency, and 1 had concomitant acute flaccid myelitis. Phylogenetic analysis showed that all of 20 sequences obtained belong to the recently described clade B3.

Phenotypic variability in patients with ADA2 deficiency due to identical homozygous R169Q mutations.

OBJECTIVE: To determine the genotype-phenotype association in patients with adenosine deaminase-2 (ADA2) deficiency due to identical homozygous R169Q mutations inCECR1 METHODS: We present a case series of nine ADA2-deficient patients with an identical homozygous R169Q mutation. Clinical and diagnostic data were collected and available MRI studies were reviewed. We performed genealogy and haplotype analyses and measured serum ADA2 activity. ADA2 activity values were correlated to clinical symptoms. RESULTS: Age of presentation differed widely between the nine presented patients (range: 0 months to 8 years). The main clinical manifestations were (hepato)splenomegaly (8/9), skin involvement (8/9) and neurological involvement (8/9, of whom 6 encountered stroke). Considerable variation was seen in type, frequency and intensity of other symptoms, which included aplastic anaemia, acute myeloid leukaemia and cutaneous ulcers. Common laboratory abnormalities included cytopenias and hypogammaglobulinaemia. ADA2 enzyme activity in patients was significantly decreased compared with healthy controls. ADA2 activity levels tended to be lower in patients with stroke compared with patients without stroke. Genealogical studies did not identify a common ancestor; however, based on allele frequency, a North-West European founder effect can be noted. Three patients underwent haematopoietic cell transplantation, after which ADA2 activity was restored and clinical symptoms resolved. CONCLUSION: This case series revealed large phenotypic variability in patients with ADA2 deficiency though they were homozygous for the same R169Q mutation inCECR1 Disease modifiers, including epigenetic and environmental factors, thus seem important in determining the phenotype. Furthermore, haematopoietic cell transplantation appears promising for those patients with a severe clinical phenotype.

Immune Dysfunction in Children with CHARGE Syndrome: A Cross-Sectional Study.

CHARGE syndrome is a variable, multiple congenital malformation syndrome. Patients with CHARGE syndrome have frequent infections that are presumed to be due to anatomical anomalies of the craniofacial region and upper airway, and cranial nerve problems resulting in swallowing difficulties and aspiration. The possible contribution of immunological abnormalities to these infections has not been systematically studied even though immune deficiencies have been described in patients with 22q11.2 deletion syndrome, a condition which shares remarkable clinical overlap with CHARGE syndrome. We assessed the frequency and nature of immune dysfunction in 24 children with genetically proven CHARGE syndrome. All patients, or their parents, completed a questionnaire on infectious history. Their immune system was extensively assessed through full blood counts, immunoglobulin levels, lymphocyte subpopulations, peripheral B- and T-cell differentiation, T-receptor excision circle (TREC) analysis, T-cell function, and vaccination responses. All CHARGE patients had a history of infections (often frequent), mainly otitis media and pneumonia, leading to frequent use of antibiotics and to hospital admissions. Decreased T-cell numbers were found in 12 (50%) patients, presumably caused by insufficient thymic output since TREC amounts were also diminished in CHARGE patients. Despite normal peripheral B-cell differentiation and immunoglobulin production in all patients, 83% of patients had insufficient antibody titers to one or more early childhood vaccinations. Based on our results, we recommend immunological evaluation of CHARGE patients with recurrent infections.

CD21 and CD19 deficiency: Two defects in the same complex leading to different disease modalities.

PURPOSE: Deficiencies in CD19 and CD81 (forming the CD19-complex with CD21 and CD225) cause a severe clinical phenotype. One CD21 deficient patient has been described. We present a second CD21 deficient patient, with a mild clinical phenotype and compared the immunobiological characteristics of CD21 and CD19 deficiency. METHODS: CD21 deficiency was characterized by flowcytometric immunophenotyping and sequencing. Real-time PCR, in vitro stimulation and next generation sequencing were used to characterize B-cell responses and affinity maturation in CD21(-/-) and CD19(-/-) B cells. RESULTS: A compound heterozygous mutation in CD21 caused CD21 deficiency. CD21(-/-) B cells responded normally to in vitro stimulation and AID was transcribed. Affinity maturation was less affected by CD21 than by CD19 deficiency. CONCLUSIONS: Both CD21 and CD19 deficiencies cause hypogammaglobulinemia and reduced memory B cells. CD19 deficiency causes a more severe clinical phenotype. B-cell characteristics reflect this, both after in vitro stimulation as in affinity maturation.

Loss of ADAM17 is associated with severe multiorgan dysfunction.

ADAM metallopeptidase domain 17 (ADAM17) is responsible for processing large numbers of proteins. Recently, 1 family involving 2 patients with a homozygous mutation in ADAM17 were described, presenting with skin lesions and diarrhea. In this report, we describe a second family confirming the existence of this syndrome. The proband presented with severe diarrhea, skin rash, and recurrent sepsis, eventually leading to her death at the age of 10 months. We performed exome sequencing and detailed pathological and immunological investigations. We identified a novel homozygous frameshift mutation in ADAM17 (NM_003183.4:c.308dupA) leading to a premature stop codon. CD4(+) and CD8(+) T-cell stimulation assays showed severely diminished tumor necrosis factor-α and interleukin-2 production. Skin biopsies indicated a focal neutrophilic infiltrate and spongiotic dermatitis. Interestingly, the patient developed unexplained systolic hypertension and nonspecific hepatitis with apoptosis. This report provides evidence for an important role of ADAM17 in human immunological response and underscores its multiorgan involvement.

CHARGE syndrome: a review of the immunological aspects.

CHARGE syndrome is caused by a dominant variant in the CHD7 gene. Multiple organ systems can be affected because of haploinsufficiency of CHD7 during embryonic development. CHARGE syndrome shares many clinical features with the 22q11.2 deletion syndrome. Immunological abnormalities have been described, but are generally given little attention in studies on CHARGE syndrome. However, structured information on immunological abnormalities in CHARGE patients is necessary to develop optimal guidelines for diagnosis, treatment and follow-up in these patients. Here, we provide an overview of the current literature on immunological abnormalities in CHARGE syndrome. We also explore immunological abnormalities in comparable multiple congenital anomaly syndromes to identify common immunological phenotypes and genetic pathways that might regulate the immune system. Finally, we aim to identify gaps in our knowledge on the immunological aspects in CHARGE syndrome that need further study.

The emergence of enterovirus D68 in a Dutch University Medical Center and the necessity for routinely screening for respiratory viruses.

BACKGROUND: Since August 2014, an increase in infections caused by enterovirus D68 (EV-D68) was reported in the USA and Canada, for the most part in children presenting with severe respiratory symptoms. OBJECTIVES: To determine whether an increase in severe EV-D68 respiratory infections was observed in our region. STUDY DESIGN: Samples from patients with respiratory symptoms were screened for viral pathogens, including rhinovirus and enterovirus. Subsequently, samples positive for rhinovirus and enterovirus were routinely sequenced for phylogenetic analysis. Furthermore, an additional method was used to detect EV-D68 specifically. RESULTS: During the first three quarters of the year 2014, 1896 respiratory samples were analyzed; 39 (2%) of them tested positive for enterovirus. Eighteen samples tested positive for EV-D68, obtained from 16 different patients admitted to our hospital. Eleven were children below the age of 18, of whom five children needed intensive care treatment. The remaining five samples were from adults, who all had an underlying disease; three were transplant patients (heart, lung and renal transplantation), the other two had an underlying lung condition (COPD, asthma). Phylogenetic analysis showed a close relationship with the strains circulating currently in the USA, all belonging to the known EV-D68 genetic subtypes. CONCLUSIONS: We observed an increase of EV-D68 infections in our population, both in children as well as in adult. In 2014 there have been 16 cases so far, compared to none in 2011 and 2013 and a single case in 2012. Phylogenetic analysis identified two similar clusters as shown in the USA and Canada.

Clinical validation of the analysis of fluconazole in oral fluid in hospitalized children.

Fluconazole is a first-line antifungal agent for the treatment and prophylaxis of invasive candidiasis in pediatric patients. Pediatric patients are at risk of suboptimal drug exposure, due to developmental changes in gastrointestinal and renal function, metabolic capacity, and volume of distribution. Therapeutic drug monitoring (TDM) can therefore be useful to prevent underexposure of fluconazole in children and infants. Children, however, often fear needles and can have difficult vascular access. The purpose of this study was to develop and clinically validate a method of analysis to determine fluconazole in oral fluid in pediatric patients. Twenty-one paired serum and oral fluid samples were obtained from 19 patients and were analyzed using a validated liquid chromatography-tandem mass spectrometry (LC-MS-MS) method after cross-validation between serum and oral fluid. The results were within accepted ranges for accuracy and precision, and samples were stable at room temperature for at least 17 days. A Pearson correlation test for the fluconazole concentrations in serum and oral fluid showed a correlation coefficient of 0.960 (P < 0.01). The mean oral fluid-to-serum concentration ratio was 0.99 (95% confidence interval [CI], 0.88 to 1.10) with Bland-Altman analysis. In conclusion, an oral fluid method of analysis was successfully developed and clinically validated for fluconazole in pediatric patients and can be a noninvasive, painless alternative to perform TDM of fluconazole when blood sampling is not possible or desirable. When patients receive prolonged courses of antifungal treatment and use fluconazole at home, this method of analysis can extend the possibilities of TDM for patients at home.

Insufficient fluconazole exposure in pediatric cancer patients and the need for therapeutic drug monitoring in critically ill children.

BACKGROUND: Fluconazole is recommended as first-line treatment in invasive candidiasis in children and infants. Although timely achievement of adequate exposure of fluconazole improves outcome, therapeutic drug monitoring is currently not recommended. METHODS: We conducted a retrospective study of critically ill children treated with fluconazole from January 2007 to October 2013 and for whom fluconazole concentrations were available. We collected demographic, clinical, and treatment data through review of the medical records and determined the correlation of clinical variables with the fluconazole concentration. Additionally, we assessed the relation between the fluconazole concentration and the time to culture conversion in patients with proven invasive candidiasis. RESULTS: In total, 99 pediatric patients met the inclusion criteria. The fluconazole concentration was considered subtherapeutic in 40% of the patients. Multiple linear regression analysis showed a significant, independent, and positive association of the fluconazole trough concentration with the fluconazole dose (P <.001), weight (P = .009), and the serum urea concentration (P = .003), and a significant, independent, and negative association with age (P = .004) and cancer as an underlying condition (P = .003). A higher fluconazole concentration was associated with a shorter time to culture conversion (hazard ratio = 1.076 [95% confidence interval, 1.017-1.138]; P = .011). CONCLUSIONS: The fluconazole concentration is not sufficient in pediatric cancer patients with the currently recommended dose regimen, and a higher fluconazole dose is required to achieve adequate drug exposure. Therapeutic drug monitoring of fluconazole can be a valuable tool to detect possible underexposure in critically ill children.

Long-term response to combination antiretroviral therapy in HIV-infected children in the Netherlands registered from 1996 to 2012.

OBJECTIVES: To describe demographic and treatment characteristics of the Dutch vertically HIV-infected paediatric population from 1996 to 2012, and to investigate the long-term virological and immunological response to combination antiretroviral therapy (cART), with emphasis on the influence of age at cART initiation and initial CD4 cell counts. DESIGN: Descriptive cohort study. METHODS: From 1996 to 2012, all paediatric HIV clinics in the Netherlands provided data on their HIV-infected population. Descriptive statistics, parametric and non-parametric comparative tests, and random-effects linear regression models were performed to investigate the different aspects of this cohort. RESULTS: A total of 229 vertically HIV-infected children were included. The majority of all mothers (64%) and almost half of the children (43%) originated from sub-Saharan Africa. Ritonavir-boosted lopinavir and efavirenz have replaced indinavir, nelfinavir and nevirapine as preferred first-line cART regimens. Long-term CD4 T-cell reconstitution (with CD4 cell counts corrected for age) was independent of age and CD4 cell count at cART initiation. The decline in HIV viral load after cART introduction occurred faster over the studied time period. The percentage of children with an undetectable viral load rose substantially from 1996 to 2012. Mortality was 0.3 per 100 person-years. CONCLUSION: A sustained immunological response in the Dutch paediatric HIV-infected population was independent of age as well as CD4 cell count at cART initiation, despite a higher initial HIV viral load in the youngest children. The percentage of children with an undetectable HIV viral load rose substantially over the years and there was a low mortality rate in comparison with reports from other industrialized countries.

Fluorescent cell barcoding as a tool to assess the age-related development of intracellular cytokine production in small amounts of blood from infants.

Fluorescent Cell Barcoding (FCB) is a flow cytometric technique which has been used for assessing signaling proteins. This FCB technique has the potential to be applied in other multiparameter analyses. Since data on antigen (Ag)-specific T-cell immune responses, like intracellular cytokine production, are still lacking in infants because limited blood volumes can be obtained for analysis, the FCB technique could be very useful for this purpose. The objectives of this study were to modify the FCB method to be able to measure multiple Ag-specific cytokine reponses in T-cells upon simultaneous stimulation by various antigens and mitogens in small amounts of blood and to investigate the cytokine pattern of T-cell subsets in healthy infants aged six and twelve months. Blood samples, collected from 20 healthy infants aged six and twelve months, were stimulated in vitro with the antigens: phorbol-myristate-acetate (PMA), purified-protein-derivative (PPD), Tetanus-toxoid (TT), Staphylococcal-enterotoxin-B (SEB), and phytohemagglutinin (PHA). Each stimulus was barcoded by labelling with different intensities of fluorescent cell barcoding (FCB) markers. Intracellular production of interleukin-2, interferon-gamma, and tumor necrosis factor-alpha was measured simultaneously in just one blood sample of 600 µl whole blood. Significant age-related differences in cytokine production were shown for PMA, PHA, and TT in CD4(+) T-cells, and for PMA, PHA, SEB, and TT in CD8(+) T-cells. The intracellular cytokine production by CD4(+) and CD8(+) T-cells was higher at twelve months compared to six months of age for all antigens, except for PMA, which was lower at the age of twelve months. Based on the consistency in both T-cell subsets, we conclude that the new FCB method is a promising tool to investigate the age-related development of intracellular cytokine production in infants.