CD38high/HLA-DR+CD8+ T lymphocytes display pathogen-specific expansion regardless of hemophagocytic lymphohistiocytosis.

The characteristic expansion of T CD38high/HLA-DR+CD8+ lymphocytes observed in hemophagocytic lymphohistiocytosis (HLH) and macrophage activation syndrome (MAS) proved able to distinguish HLH/MAS from sepsis and systemic juvenile idiopathic arthritis. However, the performance of this marker in differentiating HLH/MAS from other pediatric febrile conditions with similar clinical onset and yet entirely different treatments remains unexplored. CD38high/HLA-DR+CD8+ frequencies measured in the peripheral fresh blood of pediatric patients attended for suspicion of HLH/MAS were retrospectively recorded and clinical characteristics were retrieved. CD38high/HLA-DR+CD8+ frequencies in HLH/MAS patients (15 patients; median: 22.0%, IQR: 11.0-49.0%) were compared with those who presented febrile conditions other-than-HLH (28 patients; median: 13.0%, IQR: 3.9-28.7%; p = 0.24). HLH and non-HLH patients were subsequently regrouped based on the presence of an identified infection (22 patients; median: 27.0%, IQR: 15.2-72.1%) and compared with those without infections (21 patients; median: 7.6%, IQR: 3.7-24.3%; p = 0.0035). CD38high/HLA-DR+CD8+ percentages were significantly higher only in the infection group compared with the noninfection one, with a patent pathogen-specific expansion in Epstein-Barr virus primoinfection and visceral leishmaniasis regardless of the presence of HLH. CD38high/HLA-DR+CD8+ frequencies do not appear as an HLH-specific marker as they naturally expand in other clinical situations that are common in childhood and may mimic HLH initial presentation.

Event-free survival of maralixibat-treated patients with Alagille syndrome compared to a real-world cohort from GALA.

BACKGROUND AND AIMS: Alagille syndrome (ALGS) is characterized by chronic cholestasis with associated pruritus and extrahepatic anomalies. Maralixibat, an ileal bile acid transporter inhibitor, is an approved pharmacologic therapy for cholestatic pruritus in ALGS. Since long-term placebo-controlled studies are not feasible or ethical in children with rare diseases, a novel approach was taken comparing 6-year outcomes from maralixibat trials with an aligned and harmonized natural history cohort from the G lobal AL agille A lliance (GALA) study. APPROACH AND RESULTS: Maralixibat trials comprise 84 patients with ALGS with up to 6 years of treatment. GALA contains retrospective data from 1438 participants. GALA was filtered to align with key maralixibat eligibility criteria, yielding 469 participants. Serum bile acids could not be included in the GALA filtering criteria as these are not routinely performed in clinical practice. Index time was determined through maximum likelihood estimation in an effort to align the disease severity between the two cohorts with the initiation of maralixibat. Event-free survival, defined as the time to first event of manifestations of portal hypertension (variceal bleeding, ascites requiring therapy), surgical biliary diversion, liver transplant, or death, was analyzed by Cox proportional hazards methods. Sensitivity analyses and adjustments for covariates were applied. Age, total bilirubin, gamma-glutamyl transferase, and alanine aminotransferase were balanced between groups with no statistical differences. Event-free survival in the maralixibat cohort was significantly better than the GALA cohort (HR, 0.305; 95% CI, 0.189-0.491; p <0.0001). Multiple sensitivity and subgroup analyses (including serum bile acid availability) showed similar findings. CONCLUSIONS: This study demonstrates a novel application of a robust statistical method to evaluate outcomes in long-term intervention studies where placebo comparisons are not feasible, providing wide application for rare diseases. This comparison with real-world natural history data suggests that maralixibat improves event-free survival in patients with ALGS.

Disrupted Seasonality of Respiratory Viruses: Retrospective Analysis of Pediatric Hospitalizations in Italy from 2019 to 2023.

This multicenter study in Italian hospitals highlights the epidemiologic disruptions in the circulation of the 5 main respiratory viruses from 2019 to 2023. Our data reveal a resurgence of respiratory syncytial virus and influenza during the 2022-2023 winter season, with an earlier peak in cases for both viruses, emphasizing the importance of timely monitoring.

Efficacy and safety of DAA in children and adolescents with chronic HCV infection: A systematic review and meta-analysis.

BACKGROUND AND AIMS: We evaluated the effectiveness and safety of pan-genotypic regimens, glecaprevir/pibrentasvir (GLE/PIB), sofosbuvir/velpatasvir (SOF/VEL), and sofosbuvir/daclatasvir (SOF/DCV) and other direct-acting antivirals (DAA) regimens for the treatment of hepatitis C virus (HCV)-infected adolescents (12-18 years), older children (6-11 years), and young children (3-5 years). The purpose of this systematic review and meta-analysis was to inform the World Health Organization (WHO) guidelines. METHODS: We included clinical trials and observational studies published up to August 11, 2021, that evaluated DAA regimens in HCV-infected adolescents, older children, and young children. We searched MEDLINE, EMBASE, and CENTRAL databases and key conference abstracts. Sustained virological response 12 weeks after the end of treatment (SVR12), adverse events (AEs), and treatment discontinuation were the outcomes evaluated. Risk of bias was assessed using a modified version of the ROBINS-I tool. Data were pooled using random-effects models, and certainty of the evidence was assessed using the GRADE approach. RESULTS: A total of 49 studies including 1882 adolescents, 436 older children, and 166 young children were considered. The SVR12 was 100% (95% Confidence Interval: 96-100), 96% (90-100), and 96% (83-100) for GLE/PIB in adolescents, older, and young children, respectively; 95% (90-99), 93% (86-98), and 83% (70-93), for SOF/VEL, respectively; and 100% (97-100) and 100% (94-100) for SOF/DCV in adolescent and older children, respectively. There was a clear trend towards a higher rate of any reported AE from adolescents (50%), older children (53%), to young children (72%). Serious AEs and treatment discontinuations were uncommon in adolescents and older children (<1%) but slightly higher in young children (3%). CONCLUSIONS: All three pan-genotypic DAA regimens were highly effective and well-tolerated and are now recommended by the WHO for use in adults, adolescents, and children down to 3 years, which will simplify procurement and supply chain management. The evidence was based largely on single-arm non-randomized controlled studies. Moreover, there were also missing data regarding key variables such as route of HCV acquisition, presence or absence of cirrhosis, or HIV co-infection that precluded evaluation of the impact of these factors on outcomes. PROSPERO RECORD: CRD42020146752.

Health-related quality of life in patients aged 6-18 years with chronic hepatitis C treated with sofosbuvir/velpatasvir.

BACKGROUND & AIMS: The aim of this study was to assess the effect of treatment with sofosbuvir/velpatasvir (SOF/VEL) on the health-related quality of life (HRQL) of children with chronic hepatitis C. METHODS: In the non-commercial, non-randomized, open-label PANDAA-PED study, 50 children aged 6-18 years with chronic hepatitis C were treated with a fixed dose of SOF/VEL. All patients achieved sustained virologic response 12 weeks after the end of treatment (SVR12). Evaluation of HRQL was performed twice: at baseline (before the treatment) and during the SVR12 analysis using the KIDSCREEN-27 questionnaires, which included 5 dimensions of HRQL, for child self-reporting and parent proxy reporting. The normal range for the population was set to T values of 50 ± 10 points. Child-parent agreement was analysed using the intra-class correlation coefficient (ICC) and Bland-Altman test. RESULTS: Mean T values were within the normal range for all dimensions, both before and after treatment. There was a significant improvement in physical well-being based on the children's self-assessment (from 48.53 to 51.21, p = .03). In addition, a trend towards better scores in the 'social support & peers' part of the parent proxy evaluation (from 45.98 to 48.66, p = .06) was noticed. After the treatment, the proportion of children self-assessing their physical well-being as below normal significantly decreased from 17% to 5% (p = .007). HRQL scores were not associated with patients' sex, but in most cases, younger age correlated with better HRQL. Evaluation of the ICC for child self-reports versus parent proxy reports revealed poor to moderate agreement for most single measures. Bland-Altman analysis showed that in all dimensions, both before and after treatment, the limits of agreement (LoAs) exceeded ±5 points (half of the SD and considered a maximum allowed difference). CONCLUSIONS: A significant proportion of children with chronic hepatitis C have decreased HRQL in all dimensions, but effective treatment with SOF/VEL leads to an improvement in some areas of well-being. As the effect of HCV on HRQL is more pronounced in older patients, treatment of younger children should be indicated to prevent them from experiencing decreased HRQL due to ongoing HCV infection in the future.

Convergence and divergence in Kawasaki disease and multisystem inflammatory syndrome in children: results from the COVASAKI survey.

OBJECTIVES: To compare Kawasaki disease (KD) and multisystem inflammatory syndrome (MIS-C) in children. METHODS: Prospective collection of demographics, clinical and treatment data. Assessment of type 1 interferon (IFN) score, CXCL9, CXCL10, Interleukin (IL)18, IFNγ, IL6, IL1b at disease onset and at recovery. RESULTS: 87 patients (43 KD, 44 MIS-C) were included. Age was higher in MIS-C compared to KD group (mean 31±23 vs. 94±50 months, p<0.001). Extremities abnormalities (p=0.027), mucosal involvement (p<0.001), irritability (p<0.001), gallbladder hydrops (p=0.01) and lymphadenopathy (p=0.07) were more often recorded in KD. Neurological findings (p=0.002), gastrointestinal symptoms (p=0.013), respiratory involvement (p=0.019) and splenomegaly (p=0.026) were more frequently observed in MIS-C. Cardiac manifestations were higher in MIS-C (p<0.001), although coronary aneurisms were more frequent in KD (p=0.012). In the MIS-C group, the multiple linear regression analysis revealed that a higher IFN score at onset was related to myocardial disfunction (p<0.001), lymphadenopathy (p=<0.001) and need of ventilation (p=0.024). Both CXCL9 and CXCL10 were related to myocardial disfunction (p<0.001 and p=0.029). IL18 was positively associated to PICU admission (0.030) and ventilation (p=004) and negatively associated to lymphadenopathy (0.004). IFNγ values were related to neurological involvement and lymphadenopathy (p<0.001), IL1b to hearth involvement (0.006). A negative correlation has been observed between IL6 values, heart involvement (p=0.013) and PICU admission (p<0.001). CONCLUSIONS: The demographic and clinical differences between KD e MIS-C cohorts confirm previous reported data. The assessment of biomarkers levels at MIS-C onset could be useful to predict a more severe disease course and the development of cardiac complications.

ESPGHAN recommendations on treatment of chronic hepatitis C virus infection in adolescents and children including those living in resource-limited settings.

Hepatitis C virus (HCV) infection is a major cause of chronic liver disease worldwide, with more than three million viraemic adolescents and children. Treatment of adults with HCV infection and HCV-related liver disease has advanced considerably thanks to development and improvements in therapy. Direct-acting antiviral regimens are safe and effective. Three regimens with pangenotypic activity (glecaprevir/pibrentasvir, sofosbuvir/velpatasvir and sofosbuvir/velpatasvir/voxilaprevir) and three regimens with genotype-specific activity (sofosbuvir/ribavirin, sofosbuvir/ledipasvir and elbasvir/grazoprevir) have been approved with age-specific limitation for treatment of children with chronic hepatitis C by the European Medicines Agency and the United States Food and Drug Administration. The World Health Organization has set the ambitious target to eliminate hepatitis C as a major public health threat by 2030 and based its actions against HCV on the large use of direct acting antivirals. These updated European Society for Pediatric Gastroenterology, Hepatology and Nutrition recommendations on treatment of hepatitis C describe the optimal therapeutic management of adolescents and children with HCV infection including specific indications for those living in resource-limited settings.

Does multiple gastric aspirate collection increase sensitivity of M. tuberculosis detection in children with pulmonary tuberculosis?

This study aims to investigate the sensitivity of microscopy, culture and polymerase chain reaction on three gastric aspirates (GAs) in the microbiological confirmation of active pulmonary tuberculosis (TB) and to identify possible changes in sensitivity derived from the collection of a different number of aspirates. Children with clinical and radiological diagnoses of active pulmonary TB who underwent three GAs between March 2007 and June 2019 were retrospectively evaluated. Clinical, radiological, and microbiological data were collected. The sensitivity of microbiological tests on GAs was calculated. Moreover, differences in sensitivity according to age and radiological pattern were investigated. Overall, 156 children with active pulmonary TB were enrolled with a median age of 51.5 (IQR: 25.2-113.2) months. Microbiological investigations on the first GA showed a sensitivity of 34% (95%CI 26.7, 42), the cumulative sensitivity of first and second GAs was 40.4% (95%CI 32.7, 48.5) and of the three GAs was 47.4% (95%CI 39.8, 55.2). The collection of three GAs leads to an overall increase in sensitivity of the first GA by 13.4% (95%CI 2.8, 24.1%; p=0.014). Moreover, the increase in sensitivity was significantly higher in children ≤ 4 years of age and in those with uncomplicated TB (p=0.008).Conclusions: Performing a higher number of GAs increases the sensitivity of microbiological confirmation of active pulmonary TB, particularly in children ≤ 4 years and with an uncomplicated radiological pattern. What is known: • The diagnosis of paediatric tuberculosis is a challenge for paediatricians • Despite their low sensitivity gastric aspirates represent the standard sample for microbiological confirmation of active pulmonary tuberculosis in children • Most international guidelines recommend performing three sequential gastric aspirates on three consecutive days What is new: • A significant increase in global sensitivity by 13.4% was found by the collection of three gastric aspirates compared to the first one • Performing a higher number of gastric aspirates increases the sensitivity of microbiological confirmation, particularly in children ≤ 4 years and with an uncomplicated radiological pattern.

Acute hemorrhagic edema of infancy: 20-year experience from an Italian tertiary referral center.

PURPOSE: Data on acute hemorrhagic edema of infancy (AHEI) are derived from small case series or case reports. We report a 20-year experience at a national referral center. METHODS: We performed a single-center retrospective study including patients who were diagnosed with AHEI from January 1, 2004, to June 30, 2023. RESULTS: We identified 21 patients (57.1% females) with a median age of 18 months (range 7-33 months). Thirteen (61.9%) patients were admitted to the pediatric ward, the remaining eight (38.1%) presented to the emergency department and were discharged for outpatient management. The median length of hospitalization was 5 days (range 3-9 days). Twenty patients (95.2%) had prodromal symptoms. The most common cutaneous findings were targetoid purpuric plaques. The lesions were most localized on the face (13, 61.9%) and on the upper limbs (18 patients, 85.7%). Sixteen (76%) patients presented with nonpitting and tender edema, localized on the feet (9/16, 56%) and hands (6/16, 37.5%). Systemic involvement was rare, and no patients experienced complications or sequelae. Twelve (57.1%) patients underwent infectious disease investigations, with positive results in only four (33.3%). None of the patients diagnosed after the SARS-CoV-2 outbreak (March 2020) had positive nasopharyngeal swabs for the virus. For the 13 patients who were admitted to the pediatric ward, the median length of hospitalization was five days (3-9 days). CONCLUSIONS: The 21-patient single-center cohort of children affected by AHEI confirmed a generally benign course of AHEI, despite a 62% rate of hospitalization.

Severe A(H1N1)pdm09 influenza acute encephalopathy outbreak in children in Tuscany, Italy, December 2023 to January 2024.

A severe outbreak of influenza A(H1N1pdm09) infection in seven children (median age: 52 months) occurred between December 2023 and January 2024 in Tuscany, Italy. Clinical presentation ranged from milder encephalopathy to acute necrotizing encephalopathy (ANE) with coma and multiorgan failure; one child died. This report raises awareness for clinicians to identify and treat early acute encephalopathy caused by H1N1 influenza and serves as a reminder of severe presentations of influenza in young children and the importance of vaccination.

Spontaneous Clearance of Vertically Acquired Hepatitis C Infection: Implications for Testing and Treatment.

BACKGROUND: Current guidelines recommend that infants born to women with hepatitis C virus (HCV) viremia be screened for HCV antibody at age 18 months and, if positive, referred for RNA testing at 3 years to confirm chronic infection. This policy is based, in part, on analyses that suggest that 25%-40% of vertically acquired HCV infections clear spontaneously within 4-5 years. METHODS: Data on 179 infants with HCV RNA and/or anti-HCV evidence of vertically acquired infection in 3 prospective European cohorts were investigated. Ages at clearance of infection were estimated taking account of interval censoring and delayed entry. We also investigated clearance in initially HCV RNA-negative infants in whom RNA was not detectable until after 6 weeks. RESULTS: Clearance rates were initially high then declined slowly. Apparently, many infections clear before they can be confirmed. An estimated 65.9% (95% credible interval [CrI], 50.1-81.6) of confirmed infections cleared by 5 years, at a median 12.4 (CrI, 7.1-18.9) months. If treatment were to begin at age 6 months, 18 months, or 3 years, at least 59.0% (CrI, 42.0-76.9), 39.7% (CrI, 17.9-65.9), and 20.9% (CrI, 4.6-44.8) of those treated would clear without treatment. In 7 (6.6%) confirmed infections, RNA was not detectable until after 6 weeks and not until after 6 months in 2 (1.9%). However, all such cases subsequently cleared. CONCLUSIONS: Most confirmed infection cleared by age 3 years. Treatment before age 3, if it was available, would avoid loss to follow-up but would result in substantial overtreatment.

Overall Vertical Transmission of Hepatitis C Virus, Transmission Net of Clearance, and Timing of Transmission.

BACKGROUND: It is widely accepted that the risk of hepatitis C virus (HCV) vertical transmission (VT) is 5%-6% in monoinfected women, and that 25%-40% of HCV infection clears spontaneously within 5 years. However, there is no consensus on how VT rates should be estimated, and there is a lack of information on VT rates "net" of clearance. METHODS: We reanalyzed data on 1749 children in 3 prospective cohorts to obtain coherent estimates of overall VT rate and VT rates net of clearance at different ages. Clearance rates were used to impute the proportion of uninfected children who had been infected and then cleared before testing negative. The proportion of transmission early in utero, late in utero, and at delivery was estimated from data on the proportion of HCV RNA positive within 3 days of birth, and differences between elective cesarean and nonelective cesarean deliveries. RESULTS: Overall VT rates were 7.2% (95% credible interval [CrI], 5.6%-8.9%) in mothers who were human immunodeficiency virus (HIV) negative and 12.1% (95% CrI, 8.6%-16.8%) in HIV-coinfected women. The corresponding rates net of clearance at 5 years were 2.4% (95% CrI, 1.1%-4.1%), and 4.1% (95% CrI, 1.7%-7.3%). We estimated that 24.8% (95% CrI, 12.1%-40.8%) of infections occur early in utero, 66.0% (95% CrI, 42.5%-83.3%) later in utero, and 9.3% (95% CrI, 0.5%-30.6%) during delivery. CONCLUSIONS: Overall VT rates are about 24% higher than previously assumed, but the risk of infection persisting beyond age 5 years is about 38% lower. The results can inform design of trials of interventions to prevent or treat pediatric HCV infection, and strategies to manage children exposed in utero.

Efficacy and safety of treatment with sofosbuvir/velpatasvir in patients aged 6-18 years with chronic hepatitis C-Results of the PANDAA-PED study.

BACKGROUND AND AIMS: The aim of this non-commercial, open-label, real-life, non-randomized clinical trial was to analyse the efficacy and safety of a pangenotypic regimen sofosbuvir/velpatasvir (SOF/VEL) in patients aged 6-18 years with chronic hepatitis C virus (HCV) infection. METHODS: Fifty patients qualified for the 12-week treatment were divided into two weight groups: 15 children weighting between 17 and <30 kg received a fixed dose of 200/50 mg of SOF/VEL (tablet) once daily, and 35 patients weighting ≥30 kg were treated with 400/100 mg SOF/VEL. The primary endpoint of the study was efficacy defined as sustained viral response (undetectable HCV RNA using an real-time polymerase chain reaction method) at 12 weeks posttreatment (SVR12). RESULTS: Median age of the participants was 10 (IQR 8-12) years, 47 were infected vertically, and 3 patients were previously ineffectively treated with pegylated interferon and ribavirin. Thirty-seven participants were infected with HCV genotype 1, 10 with HCV genotype 3 and the remaining 3 with genotype 4. There was no case of cirrhosis. SVR12 was 100%. Thirty-three reported adverse events (AEs) were considered related to the administration of SOF/VEL, all of them were mild or moderate. Children presenting with AEs were older compared to these without AEs: 12 (9.5-13) versus 9 (IQR 8-11) years (p = 0.008). CONCLUSIONS: Results of the PANDAA-PED study indicated a 100% effectiveness of a 12-week therapy with SOF/VEL in children aged 6-18 years with chronic HCV infection and its good safety profile, in particular in younger patients.

Inadequate Hospital Practices to Prevent Mother-to-Child Transmission of Hepatitis B Virus Infection: A European Survey.

OBJECTIVES: Prevention of vertical transmission of hepatitis B virus (HBV) infection is crucial to eliminate viral hepatitis as a major public health threat by 2030. We aimed to assess the current hospital policies and practices implemented before, at, and after birth, and to evaluate potential barriers to the full application of international guidelines. METHODS: A web-based survey was supported by PENTA Foundation and distributed across Europe from October to December 2021. RESULTS: Overall, 76 centers with delivery departments completed the survey. Hepatitis B surface antigen (HBsAg) maternal screening is performed in the first trimester of pregnancy in 53% of the centers and in the third in 46%. HBsAg positive pregnant women are tested for serologic HBV markers and HBV-DNA in 78% and 63% of the departments; 38% of the HBeAg positive women with high HBV-DNA levels are treated during the last trimester of pregnancy. At birth, 91% of the departments administer HBV vaccine to infants born to HBsAg positive mothers within 12 hours of birth; 74% test women with unknown HBsAg status and 78% of them wait for the maternal testing results before administering HBV vaccine to their newborns. After birth, 47% of the departments provide postvaccination serological testing for infants born to HBsAg positive mothers. The timing of the HBV vaccine schedule varies greatly. CONCLUSIONS: There is significant heterogeneity in the hospital policies and correlated procedures. The implementation of a multidisciplinary clinical pathway is a must if a stronger connection between the prenatal, perinatal, and postnatal phases is to be established.

Anticoagulation and Thrombotic Events in the Multisystem Inflammatory Syndrome in Children: Experience of a Single-center Cohort and Review of the Literature.

The multisystem inflammatory syndrome in children (MIS-C) is a severe clinical entity affecting the coagulative system; although thromboembolic events (TEs) are not common, most patients receive anticoagulation. We retrospectively assessed patients below 18 years admitted with MIS-C at Meyer Children's Hospital (Florence, Italy). Data on baseline clinical and laboratory presentation, treatment, and outcome, including differences between patients with and without thrombotic prophylaxis, were analyzed. Thirty-two children 1 to 15 years were included. Seventeen patients (53.1%) required intensive care admission, 2 (8.7%) had obesity, 7 (30.4%) a central venous catheter, and 14 (43.8%) an impaired cardiac function. Twelve patients (37.5%) received prophylactic anticoagulation: they had more frequent cardiac involvement (91.7 vs. 50%, P =0.02) and higher ferritin levels (median 1240 vs. 501.5 ng/mL, P <0.001). No differences were found in median d -dimers between the 2 groups. Twenty-one patients (65.6%) had d -dimers >5×upper limit of normal but the indication for anticoagulation was not driven by d -dimers. No patient had hemorrhagic events and only 1 patient (3.1%) had a superficial thrombotic event (under thromboprophylaxis). Our series and the available literature data on MIS-C and thromboembolic events suggest that TEs are a rare complication of MIS-C that is frequently associated with high d -dimer values. However, also in MIS-C, the well-established risk factors of pediatric TEs (ie, older age, central venous catheter, obesity, and cancer) should guide thromboembolic risk assessment.

Erythema nodosum in children: a cohort study from a tertiary pediatric hospital in Italy.

Erythema nodosum (EN), although relatively uncommon in the pediatric population, is the most frequent type of panniculitis in children. The present study aimed to report all the cases of children admitted to our tertiary pediatric hospital with the diagnosis of EN to evaluate the epidemiology, clinical manifestations, etiology, treatment, and the course of this disease in the pediatric age. This observational study retrospectively considered all children evaluated to the emergency room (ER) of Meyer Children's University Hospital, Florence, Italy, discharged with a diagnosis of EN over a 12-year period (from January 2009 to December 2021). Clinical and laboratory data were recorded using a standardized report form. Sixty-eight patients with EN were included. The etiologic diagnosis of EN was made in 38 children (55.9%): 29 (42.6%) had infection-related EN (in particular EBV and ß-hemolytic streptococcus), 6 (8.8%) had Crohn's disease, 1 celiac disease, 1 Sjogren syndrome, and 1 Hodgkin lymphoma. In 30 patients (45%), no definitive diagnosis was reached, and they were defined as having idiopathic EN. Most of the laboratory tests were nonspecific. No statistical differences were found in the demographic and clinical data, and the main diagnostic laboratory parameters between patients with idiopathic EN versus those with secondary EN.  Conclusion: Since EN can be isolated or the first manifestation of heterogeneous underlying pathologies, some of which can be severe and life-threatening, it is important to recognize it and carry out all the necessary etiological diagnostic investigations to understand its etiology and start the specific treatment. What is Known: • Erythema nodosum (EN) is the most frequent type of panniculitis in children. • It has been associated with a wide spectrum of disorders, such as different types of infection, malignancies, chronic inflammations, and drugs. What is New: • No statistical differences can be found in clinical features as well as laboratory data, between patients with idiopathic EN versus those with secondary EN. • A broad spectrum of investigations and a proper follow-up should be taken into account in order to prevent a delayed or missed secondary EN diagnosis.

SNPs of the IFNL favour spontaneous clearance of HCV infection in children.

BACKGROUND: Both spontaneous and treatment-induced clearance of hepatitis C virus (HCV) in adults have been associated with genetic polymorphisms in the interferon-λ genes. The aim of the present study was to confirm the association between the rs12979860 and evaluate the association between the rs368234815 and the rs4803217 single-nucleotide polymorphisms (SNPs) of the interferon-λ genes and the outcome of the infection in children. METHODS: Alleles and genotypes frequencies of 32 children, who presented spontaneous clearance of the virus and 135 children, with viral persistence were compared with ethnically matched controls obtained from the 1000 Genomes Project and the International HapMap Project databases. RESULTS: The frequencies of the C/C genotype of rs12979860, the TT/TT of the rs368234815 and the A/C of the rs4803217 were higher in the clearance group than in children with viral persistence (C/C versus T/T + C/T odds ratio (OR): 2.6; 90% confidence intervals (CI): 1.3-5; p = 0.01; TT/TT versus ΔG/TT + ΔG/ΔG OR: 2.8; 90% CI: 1.4-5.5; p = 0.01; and A/A versus A/C OR: 8.3; 90% CI: 1.5-45.9; p = 0.017, respectively) and with the ethnically matched controls. CONCLUSIONS: The rs12979860, the rs368234815 and the rs4803217 SNPs are associated with spontaneous clearance of HCV in children. IMPACT: Innate immune system response has a key role in the outcome of vertically acquired HCV infection in children. The rs12979860, the rs368234815 and the rs4803217 SNPs are associated with spontaneous clearance of HCV in children. Interferons-λ activate the Janus kinase-Stat pathway, which in turn induces several interferon-stimulated genes, leading to suppression of HCV replication both in vivo and in vitro.

De Novo Food Allergy in Pediatric Recipients of Liver Transplant.

ABSTRACT: Allergic and atopic conditions, including food allergy, asthma, eczema and eosinophilic disease of the gastrointestinal tract after liver transplant in previously non-allergic children have been increasingly described. After a liver transplant, children can present mild to severe reactions to food allergens (ie, from urticaria-angioedema to life-threatening anaphylactic reactions). De novo post-transplant food allergy may become clinically evident in children who undergo liver transplant between a few months and a few years of transplant. The present narrative review aims to describe the spectrum of de novo post-transplant food allergy development, the current theories of pathogenesis, risk factors and to suggest possible clinical management strategies.

Epidemiology and Natural History of Childhood-Acquired Chronic Hepatitis C: A Single-Center Long-Term Prospective Study.

OBJECTIVES: To prospectively describe the epidemiology and long-term outcome of childhood-acquired hepatitis C virus (HCV) infection in a large cohort of children followed at a single center. METHODS: All children with chronic HCV infection followed at the Liver Unit of our tertiary Hospital in Florence (Italy) from January 1, 1988, to September 30, 2021, were included in the analysis. RESULTS: The final sample consisted of 163 children (median age at enrollment 4 years, interquartile range (IQR): 10; median age at last follow-up 14 years, IQR: 7). The median duration of follow-up was 86 months (IQR: 112). One hundred twenty-five children were vertically infected and 26 acquired the infection horizontally. Twenty-six of the 125 children who were vertically infected (20.8%) underwent spontaneous clearance of HCV RNA at a median age of 4 years (IQR: 2), whereas all the others remained persistently viremic. One patient was diagnosed with cirrhosis; 2 presented clinically detectable extrahepatic manifestations (chronic urticaria). Thirty-two children (19.6%) received antiviral therapy: 8 out of 32 (25%) were treated with pegylated-interferon alfa-2b [sustained virological response (SVR) 24 weeks after the end of treatment in 7/8]; 24 out of 32 (75%) were treated with direct-acting antivirals (SVR 12 weeks after the end of treatment in 23/24). CONCLUSIONS: The present study describes the largest cohort of children with chronic HCV infection prospectively evaluated with a long follow-up at a single center. HCV infection in children is often a chronic infection that can be cured with modern antiviral therapy. Early treatment could prevent the development of advanced liver disease.

The Impact of Severe Acute Respiratory Syndrome Coronavirus Type 2 on Children With Liver Diseases: A Joint European Society for Pediatric Gastroenterology, Hepatology and Nutrition and Society of Pediatric Liver Transplantation Position Paper.

ABSTRACT: Children are seldom affected by severe forms of severe acute respiratory syndrome coronavirus type 2 (SARS-CoV2) infection; however, the impact of comorbidities in the clinical presentation and outcome of SARS-CoV2 in children is poorly characterized including that of chronic liver disease (CLD) and those taking immunosuppressive medications for autoimmune liver disease or following liver transplantation (LT). Although not the main target organ, a spectrum of liver involvement has been described in children infected with SARS-CoV2 and those presenting with Multisystem Inflammatory Syndrome in Children (MIS-C). The Hepatology Committee of the European Society for Pediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) and the Society of Pediatric Liver Transplantation (SPLIT) present an evidence-based position paper on liver involvement in children with SARS-CoV2 infection and its impact on those with CLD as well as LT recipients. All children may exhibit acute liver injury from SARS-CoV2 infection, and those with CLD and may experience hepatic decompensation. Preventative and therapeutic measures are discussed.