Adaptive immune response to BNT162b2 mRNA vaccine in immunocompromised adolescent patients

Protective immunity against COVID-19 is orchestrated by an intricate network of innate and adaptive anti-viral immune responses. Several vaccines have been rapidly developed to combat the destructive effects of COVID-19, which initiate an immunological cascade that results in the generation of neutralizing antibodies and effector T cells towards the SARS-CoV-2 spike protein. Developing optimal vaccine-induced anti-SARS- CoV-2 protective immunity depends on a fully competent immune response. Some evidence was gathered on the effects of vaccination outcomes in immunocompromised adult individuals. Nonetheless, protective immunity elicited by the Pfizer Biontech BNT162b2 vaccine in immunocompromised adolescents received less attention and was mainly focused on the antibody response and their neutralization potential. The overall immune response, including T-cell activities, was largely understudied. In this study, we characterized the immune response of vaccinated immunocompromised adolescents. We found that immunocompromised adolescents, which may fail to elicit a humoral response and develop antibodies, may still develop cellular T-cell immunity towards SARS-CoV-2 infections. Furthermore, most immunocompromised adolescents due to genetic disorders or drugs (Kidney and liver transplantation) still develop either humoral, cellular or both arms of immunity towards SARS-CoV-2 infections. We also demonstrate that most patients could mount a cellular or humoral response even after six months post 2nd vaccination. The findings that adolescents immunocompromised patients respond to some extent to vaccination are promising. Finally, they question the necessity for additional vaccination boosting regimens for this population who are not at high risk for severe disease, without further testing of their post-vaccination immune status

Once-Versus Twice-daily Mesalazine to Induce Remission in Paediatric Ulcerative Colitis : A Randomised Controlled Trial

Background: Trials in adults suggested that, in ulcerative colitis [UC], once-daily [OD] dosing of 5-ASA [5-amino salicylic acid] may be as or more effective than twice-daily [BD] dosing. In this induction of remission, investigator-blinded, randomised controlled-trial, we aimed to compare effectiveness and safety of once-versus twice-daily mesalazine in paediatric UC. Methods: Children, aged 4-18 years with a PUCAI [Paediatric Ulcerative Colitis Activity Index] of 10-55 points at inclusion, were randomised in blocks of six with blinded allocation to OD or BD mesalazine, using a weight-based dosing table. The primary outcome was mean PUCAI score at Week 6. Results: A total of 83/86 randomised children were eligible and analysed: 43 in the OD group and 40 in the BD group (mean age 14 +/- 2.7 years, 43 [52%] males, 51 [62%] extensive colitis). The groups did not differ with regard to disease activity or any other parameter at baseline. There was no difference in median PUCAI score between the OD group and BD group at Week 6: 15 (interquartile range [IQR] 5-40) versus 10 [0-40]; p = 0.48]. Response was seen in 25 [60%] OD versus 25 [63%] BD dosing [p = 0.78]. Proportion of children in remission [PUCAI 0.2]. Conclusions: In this first randomised controlled trial in children, no differences were found between OD and BD dosing for any clinical outcome. Remission was achieved in 35% of children treated with mesalazine for active UC.Peer reviewe

Genotype-phenotype relationships of truncating mutations, p.E297G and p.D482G in bile salt export pump deficiency

Background &amp; Aims: Bile salt export pump (BSEP) deficiency frequently necessitates liver transplantation in childhood. In contrast to two predicted protein truncating mutations (PPTMs), homozygous p.D482G or p.E297G mutations are associated with relatively mild phenotypes, responsive to surgical interruption of the enterohepatic circulation (siEHC). The phenotype of patients with a compound heterozygous genotype of one p.D482G or p.E297G mutation and one PPTM has remained unclear. We aimed to assess their genotype-phenotype relationship. Methods: From the NAPPED database, we selected patients with homozygous p.D482G or p.E297G mutations (BSEP1/1; n = 31), with one p.D482G or p.E297G, and one PPTM (BSEP1/3; n = 30), and with two PPTMs (BSEP3/3; n = 77). We compared clinical presentation, native liver survival (NLS), and the effect of siEHC on NLS. Results: The groups had a similar median age at presentation (0.7-1.3 years). Overall NLS at age 10 years was 21% in BSEP1/3 vs. 75% in BSEP1/1 and 23% in BSEP3/3 (p &lt;0.001). Without siEHC, NLS in the BSEP1/3 group was similar to that in BSEP3/3, but considerably lower than in BSEP1/1 (at age 10 years: 38%, 30%, and 71%, respectively; p = 0.003). After siEHC, BSEP1/3 and BSEP3/3 were associated with similarly low NLS, while NLS was much higher in BSEP1/1 (10 years after siEHC, 27%, 14%, and 92%, respectively; p &lt;0.001). Conclusions: Individuals with BSEP deficiency with one p.E297G or p.D482G mutation and one PPTM have a similarly severe disease course and low responsiveness to siEHC as those with two PPTMs. This identifies a considerable subgroup of patients who are unlikely to benefit from interruption of the enterohepatic circulation by either surgical or ileal bile acid transporter inhibitor treatment. Impact and implications: This manuscript defines the clinical features and prognosis of individuals with BSEP deficiency involving the combination of one relatively mild and one very severe BSEP deficiency mutation. Until now, it had always been assumed that the mild mutation would be enough to ensure a relatively good prognosis. However, our manuscript shows that the prognosis of these patients is just as poor as that of patients with two severe mutations. They do not respond to biliary diversion surgery and will likely not respond to the new IBAT (ileal bile acid transporter) inhibitors, which have recently been approved for use in BSEP deficiency.</p

Genotype-phenotype relationships of truncating mutations, p.E297G and p.D482G in bile salt export pump deficiency

Background & Aims: Bile salt export pump (BSEP) deficiency frequently necessitates liver transplantation in childhood. Homozygous p.D482G or p.E297G mutations are associated with relatively mild phenotypes, responsive to surgical interruption of the enterohepatic circulation (siEHC), in contrast to patients with two predicted protein truncating mutations (PPTM). The phenotype of patients with a compound heterozygous genotype of one p.D482G or p.E297G mutation and one PPTM has remained unclear. We aimed to assess their genotype-phenotype relationship. Methods: From the NAPPED database, we selected patients with homozygous p.D482G or p.E297G mutations (BSEP1/1; n=31), with one p.D482G or p.E297G, and one PPTM (BSEP1/3; n=30), and with two PPTMs (BSEP3/3; n=77). We compared presentation, native liver survival (NLS), and effect of siEHC on NLS. Results: The groups had a similar median age at presentation (0.7-1.3 years). Overall NLS at age 10 years was 21% in BSEP1/3 vs. 75% in BSEP1/1 and 23% in BSEP3/3 (P<0.001). Without siEHC in their follow-up, NLS of BSEP1/3 was similar to BSEP3/3 patients, but considerably lower than BSEP1/1 patients (at age 10 years: 38%, 30%, and 71%, resp; P=0.003). After siEHC, BSEP1/3 and BSEP3/3 patients had similarly low NLS, while this was much higher in BSEP1/1 patients (10 years after siEHC, 27%, 14%, and 92%, resp.; P<0.001). Conclusions: BSEP deficiency patients with one p.E297G or p.D482G mutation and one PPTM have a similarly severe disease course and low responsiveness to siEHC as patients with two PPTMs. This identifies a considerable subgroup of patients who are unlikely to benefit from interruption of the enterohepatic circulation by either surgical or ileal bile acid transporter inhibitor treatment

Acute Hepatitis of Unknown Aetiology Among Young Children: Research Agenda by the ESPGHAN Hepatology Committee

In April 2022, an increased incidence of acute hepatitis cases of unknown aetiology among previously healthy children across the United Kingdom was described. Since, more than 200 cases from United Kingdom and hundreds more from all across the world have been reported. The majority of affected children were younger than six years of age. The clinical presentation was nonspecific with diarrhoea and vomiting usually preceding the appearance of jaundice, abdominal pain, nausea and malaise. Approximately 10% have required liver transplantation. An infectious aetiology has been considered likely given the epidemiological and clinical features of the reported cases. More than 60% of the children tested were diagnosed with adenovirus infection although a clear aetiological connection has still to be demonstrated. No link with SARS-CoV-2 infection and COVID-19 vaccine was found. What is not clear to date is whether the high number of acute hepatitis cases reported is related to a true increase in incidence or heightened awareness following on from the initial reports from the United Kingdom. The Hepatology Committee of the European Society of Pediatric Gastroenterology, Hepatology and Nutrition developed a paper on the current outbreak of acute hepatitis of unknown aetiology recognizing its importance and the need of approaching the current situation with a scientifically rigorous approach. The aims of the paper are to summarize the current knowledge and to identify the most pertinent issues regarding the diagnosis and management of this condition and the research questions raised

Mesalamine Enemas for Induction of Remission in Oral Mesalamine-refractory Pediatric Ulcerative Colitis : A Prospective Cohort Study

Background: Paediatric ulcerative colitis [UC] is more extensive than adult disease, and more often refractory to mesalamine. However, no prospective trials have evaluated mesalamine enemas for inducing remission in children. Our goal was to evaluate the ability of mesalamine enemas to induce remission in mild to moderate paediatric UC refractory to oral mesalamine. Methods: This was an open-label arm of a previously reported randomised controlled trial of once-daily mesalamine in active paediatric UC [MUPPIT trial]. Children aged 4-18 years, with a Paediatric Ulcerative Colitis Activity Index [PUCAI] score of 10-55, were enrolled after failing at least 3 weeks of full-dose oral mesalamine. Patients treated with steroids or enemas in the previous month and those with isolated proctitis were excluded. Children received Pentasa (R) enemas 25 mg/kg [up to 1g] daily for 3 weeks with the previous oral dose. The primary endpoint was clinical remission by Week 3. Results: A total of 38 children were enrolled (mean age 14.6 +/- 2.3 years; 17/38 [45%] with extensive colitis). Clinical remission was obtained in 16 [42%] and response was obtained in 27 [71%] at Week 3. Eight children deteriorated and required steroids. There were no differences in baseline parameters between those who entered or failed to enter remission, including disease extent [43% in left-sided and 41% in extensive colitis] and disease activity [44% in mild and 41% in moderate activity]. Conclusion: Clinical remission can be markedly increased in children who are refractory to oral mesalamaine by adding mesalamine enemas for 3 weeks, before commencing steroids.Peer reviewe

Treatment of Chronic Hepatitis C Virus Infection in Children : A Position Paper by the Hepatology Committee of European Society of Paediatric Gastroenterology, Hepatology and Nutrition

Objectives: In 2017, the European Medicines Agency and the Food and Drug Administration approved the use of the fixed-dose combination of ledipasvir/sofosbuvir and of the combination of sofosbuvir and ribavirin for treatment of adolescents (12-17 years or weighing >35 kg) with chronic hepatitis C virus (HCV) genotype 1, 4, 5, and 6 and genotype 2 and 3 infections, respectively. Although trials with direct-acting antivirals are ongoing for younger children, the only available treatment in the United States and Europe for those <12 years is still the dual therapy of pegylated interferon and ribavirin. There is currently a lack of a systematic approach to the care of these patients. The Hepatology Committee of the European Society of Pediatric Gastroenterology, Hepatology and Nutrition developed an evidence-based position paper for the management of chronic HCV infection in children. Methods: A systematic literature search and meta-analysis were performed using MEDLINE and Embase from June 1, 2007 to June 1, 2017. The approach of the Grading of Recommendations Assessment, Development and Evaluation was applied to evaluate outcomes. European Society of Pediatric Gastroenterology, Hepatology and Nutrition Committee members voted on each recommendation, using the nominal voting technique. Results: The efficacy of the different direct-acting antivirals combinations tested was higher, the relapse and the treatment discontinuation rates lower when compared to pegylated interferon and ribavirin. Conclusions: This position paper addresses therapeutic management issues including goals, endpoints, indications, contraindications, and the optimal treatment regimen in children with chronic HCV infection

Management of Hepatitis B Virus Infection and Prevention of Hepatitis B Virus Reactivation in Children With Acquired Immunodeficiencies or Undergoing Immune Suppressive, Cytotoxic, or Biological Modifier Therapies :

Reactivation of hepatitis B virus (HBV) is a known complication of immune-suppressive, cytotoxic, and biological modifier therapies in patients currently infected with HBV or who have had past exposure to HBV. Nowadays, newer and emerging forms of targeted biologic therapies are available for the management of rheumatologic conditions, malignancies, inflammatory bowel disease, dermatologic conditions and solid-organ, bone marrow, or haematologic stem cell transplant but there is currently a lack of a systematic approach to the care of patients with or at risk of HBV reactivation. The Hepatology Committee of the European Society of Pediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) together with a working group of ESPGHAN members with clinical and research expertise in viral hepatitis developed an evidence-based position paper on reactivation of HBV infection in children identifying pertinent issues addressing the diagnosis, prevention, and treatment of this condition. Relevant clinical questions were formulated and agreed upon by all the members of the working group. Questions were answered and positions were based on evidence resulting from a systematic literature search on PubMed and Embase from their inception to July 1, 2019. A document was produced and the working group and ESPGHAN Hepatology Committee members voted on each recommendation, using a formal voting technique. A recommendation was accepted provided upon agreement by at least 75% of the working group members. This position paper provides a comprehensive update on the diagnosis, prevention and treatment of HBV reactivation in children