Adeno-associated viral vector gene therapy: Challenges for the paediatric hepatologist.

Hepatoxicity associated with recombinant adeno-associated virus gene therapy is being increasingly encountered by hepatologists in tertiary and quaternary referral units due to the recent increase of these therapies for neuromuscular and haematological disorders. The challenges in managing the condition stem from a lack of good-quality evidence on the appropriate protocols for immunosuppressants due to lack of representative animal models. There is a need for protocols for diagnosing and treating hepatotoxicity and this possible with further research to understand the problem and its management. The review also highlights the importance of a multidisciplinary team in managing hepatotoxicity and recommends further research to better identify at-risk individuals, define the extent of the problem and assess the long-term effects of liver injury and immunosuppressants.

Outbreak of indeterminate acute liver failure in children with adenoviraemia - Not a new disease.

BACKGROUND & AIMS: In the year 2022, an outbreak of indeterminate acute hepatitis and indeterminate paediatric acute liver failure (ID-PALF) in association with adenoviraemia in immunocompetent children was reported in the UK. We postulate that this association is not a new disease in immunocompetent children. METHODS: Children with acute hepatitis during the outbreak who were referred to King's College Hospital, London for advice and management were included in the study. Data on the frequency of ID-PALF in 2022, as well as transplantation rates and the association with adenovirus infection, were obtained from electronic health records. The clinical presentation, histology and outcomes of children with ID-PALF and adenoviraemia in 2017-2021 were compared with those in 2022. RESULTS: From January to June 2022, 65 patients with acute hepatitis were referred. Ten children were admitted with ID-PALF. ID-PALF constituted 26% of all PALF cases in 2017-2021, in contrast to 58.8% during the 2022 outbreak. During the outbreak, adenoviraemia was present in 52% of children with acute hepatitis without liver failure (in whom adenoviraemia test results were available) and in 100% of ID-PALF cases. Adenoviraemia was seen in immunocompetent children in 6/13 (46%) of all ID-PALF cases between 2017-2019, with a clear absence of adenoviraemia in the 6 ID-PALF cases during 2020-2021. Compared to ID-PALF with adenoviraemia in 2017-2019 (n = 6), ID-PALF with adenoviraemia during the outbreak (n = 10) was associated with more frequent hepatic encephalopathy, hypotension requiring vasoactive medications and higher plasma ammonia levels (admission and peak), with similar native liver survival. CONCLUSIONS: The recent outbreak of ID-PALF with adenoviraemia in immunocompetent children does not appear to be a new disease, contrary to perception and other reports. The frequency of such cases over the years could be linked to background rates of adenovirus infections. IMPACT AND IMPLICATIONS: Indeterminate paediatric acute liver failure (ID-PALF) associated with adenoviraemia in immunocompetent children is not a new disease specific to 2022. The exclusive role of human adenovirus infection in the causation of this outbreak of acute hepatitis seems unlikely. Indeed, we provide histological data from explants in transplanted patients that do not support direct viral cytotoxicity. The disease is probably mediated by immunological injury directed towards adenovirus infection and/or adeno-associated virus-2.

Emergencies in paediatric hepatology.

The aetiology of several liver diseases in children is age specific and many of these conditions have significant and potentially long-term clinical repercussions if not diagnosed early and managed in a timely fashion. We address 5 clinical scenarios that cover most of the diagnostic and therapeutic emergencies in children: infants with liver disease; acute liver failure; management of bleeding varices; liver-based metabolic disorders; and liver tumours and trauma. A wide spectrum of conditions that cause liver disease in infants may present as conjugated jaundice, which could be the only symptom of time-sensitive disorders - such as biliary atresia, metabolic disorders, infections, and haematological/alloimmune disorders - wherein algorithmic multistage testing is required for accurate diagnosis. In infantile cholestasis, algorithmic multistage tests are necessary for an accurate early diagnosis, while vitamin K, specific milk formulae and disease-specific medications are essential to avoid mortality and long-term morbidity. Management of paediatric acute liver failure requires co-ordination with a liver transplant centre, safe transport and detailed age-specific aetiological work-up - clinical stabilisation with appropriate supportive care is central to survival if transplantation is indicated. Gastrointestinal bleeding may present as the initial manifestation or during follow-up in patients with portal vein thrombosis or chronic liver disease and can be managed pharmacologically, or with endoscopic/radiological interventions. Liver-based inborn errors of metabolism may present as encephalopathy that needs to be recognised and treated early to avoid further neurological sequelae and death. Liver tumours and liver trauma are both rare occurrences in children and are best managed by a multidisciplinary team in a specialist centre.

Acute Motor Axonal Polyneuropathy Following Mumps Infection in a 9-Year-Old Girl.

A 9-year-old girl presented with lower motor neuron type of paralysis involving limbs, trunk and multiple cranial nerves (7, 9 and 10) with preceding history of mumps 1 week before the onset of weakness. There were no features to suggest either a meningitis or encephalitis in the child. Cerebrospinal fluid showed hypoglycorrhachia and mild protein elevation; magnetic resonance imaging of the brain was normal. Nerve conduction study showed motor axonal neuropathy. Serology for mumps IgM was positive, consistent with a diagnosis of post-mumps acute motor axonal polyneuropathy. The girl made a complete recovery within 3 weeks.

Yield and Examiner Dependence of Digital Rectal Examination in Detecting Impaction in Pediatric Functional Constipation.

OBJECTIVES: Guidelines on functional constipation recommend digital rectal examination (DRE) when constipation is doubtful or with a suspicion of organic etiology. The guidelines do not clarify if DRE is mandatory to diagnose impaction. This study aims to determine the frequency of impaction detectable only on DRE among children satisfying Rome III criteria without requiring DRE and also the inter-observer influences on impaction detection by DRE. METHODS: Children between 6 months to 13 years of age, presenting with history suggestive of constipation were assessed. After excluding those with suspicion of organic etiology, those who needed DRE for diagnosis of constipation and those who do not satisfy Rome III criteria without DRE, the rest who satisfied Rome III criteria were assessed for impaction by palpable fecoliths or constipation-associated fecal incontinence. Those without such impaction were randomized to 2 examiners for DRE to diagnose impaction, in the absence of contraindications. RESULTS: Two hundred and thirty-three children were assessed. One hundred and sixty-nine satisfied Rome III without needing DRE. Forty-eight (28.4%) had impaction detectable without DRE. Among the rest, 28 (30.1%) had impaction by DRE. There was no difference between the frequency of impaction detected by the 2 examiners. Clinical characteristics were similar (P > 0.05) between those with impaction detectable by DRE and those without. CONCLUSIONS: DRE does detect cases of impaction not discernible by other means. Such a finding may be comparable between examiners. These children may be identified by other clinical characteristics. The clinical significance of such a finding needs more understanding from the standpoint of therapeutic choices.

Stroop Test Validation to Screen for Minimal Hepatic Encephalopathy in Pediatric Extrahepatic Portal Venous Obstruction.

OBJECTIVES: Minimal hepatic encephalopathy (MHE) has been reported in children with extrahepatic portal vein obstruction (EHPVO). MHE assessment is restricted to research situations as neuropsychiatric tests are time-intensive. Computerized Stroop Test (CST) has been used in cirrhotic adults for MHE screening. The study aims to assess MHE frequency in young Indian children with EHPVO and validate CST for MHE screening in pediatric EHPVO. METHODS: Thirty-seven children with EHPVO between 7 and 12 years of age and 37 age- and sex-matched controls were enrolled. Fasting plasma ammonia was measured. MHE was diagnosed by Revised Amsterdamse Kinder Intelligentie Test. The performance of a Tamil language version of CST in MHE screening was assessed. RESULTS: MHE was diagnosed in 18.9% (7/37) of EHPVO (EHPVO-MHE). Plasma ammonia levels were higher in EHPVO-MHE compared to EHPVO without MHE (EHPVO-No-MHE) but abnormal plasma ammonia levels are unsuitable for MHE screening. CST was administered in 35 EHPVO and 37 controls. EHPVO-MHE, compared to EHPVO-No-MHE, had longer "on time," "off time," "(on+off) time," and "(on-off) time." For MHE diagnosis, specificity and sensitivity of "(on+off) time" were 100% and 89.6% for a cutoff of >180.4 seconds (area under receiver operating characteristic = 0.97). CONCLUSIONS: In the absence of other risk factors for neurological insult or patent surgical shunts, MHE frequency in young Indian children with EHPVO, determined by Revised Amsterdamse Kinder Intelligentie Test, was lesser than in earlier studies. CST is suitable for MHE screening in clinical practice to select patients for neuropsychiatric evaluation.

Hemophagocytic Lymphohistiocytosis in A Child With Very Severe Aplastic Anemia: Double Jeopardy Resulting in Fatality.

A 7-year-old male child with very severe aplastic anemia developed refractory disease, which was attributed to febrile hemolytic transfusion reactions and was treated with immunosuppressants, which lead to a transient improvement. However, the child worsened subsequently and succumbed to an underlying hemophagocytic lymphohistiocytosis that was recognized late due to an overlap of clinical and biochemical parameters in both the conditions. Hemophagocytic lymphohistiocytosis should be an early suspicion in children with refractory very severe aplastic anemia and the detection of underlying gene mutations can predict disease severity.

Validation of Adapted Dartmouth Operative Conditions Scale for sedation during pediatric esophagogastroduodenoscopy.

AIMS: Pediatric esophagogastroduodenoscopy requires deep sedation as it involves stimulation of the airway. Frequency of adverse events is higher with esophagogastroduodenoscopy. Hence, monitoring needs sedation scales like the Dartmouth Operative Condition Scale that identifies safe states of sedation. This study aims at validating the Adapted Dartmouth Operative Condition Scale for sedation rating by pediatricians during pediatric esophagogastroduodenoscopy. METHODS: Items in the Dartmouth Operating Conditions Scale were adapted for pediatric esophagogastroduodenoscopy. Videos of 35 procedures were recorded. The recording started 10 min before sedation and continued till recovery. The videos were split into preprocedure videos, intraprocedure videos, and recovery videos, and further split into 30-s clips. Twenty representative intraprocedure videos clips were selected. Ten raters scored the videos with the Adapted Dartmouth Operating Conditions Scale and modified-COMFORT score. The Adapted Dartmouth Operating Conditions Scale scoring was repeated after a month. The preprocedure videos, intraprocedure videos, and recovery videos of ten patients (six clips each) were scored by one rater to assess responsiveness. RESULTS: The Adapted Dartmouth Operating Conditions Scale detected nonoptimal sedation states including laryngospasm due to undersedated states. It showed fair interrater reliability at timeline-1 (intraclass correlation coefficient = 0.45) and timeline-2 (intraclass correlation coefficient = 0.65) but poor intrarater reliability (intraclass correlation coefficient = 0.32). There was significant positive correlation with modified-COMFORT (Spearman's rank order correlation, r = 0.150). Responsiveness was demonstrated by the difference in the preprocedure videos, intraprocedure videos, and recovery videos scores (F = 126.50). CONCLUSION: The Adapted Dartmouth Operating Conditions Scale detects nonoptimal sedation states during pediatric-esophagogastroduodenoscopy. It shows good criterion validity, interrater reliability, and responsiveness. Poor intrarater reliability seen in our study could be due to item ambiguity arising from the mode of training of the raters in the Dartmouth Operating Conditions Scale.

Chronic Pruritus in an 18-Month-Old Male Infant Due to Anicteric Cholestasis.

An 18-month-old male infant was referred to us with pruritus from 6 months of age. He was being managed as atopic eczema with emollients and antihistamines without any response to treatment. On examination, he was found to have extensive scratch marks, mild hepatomegaly and no icterus. Blood investigations were suggestive of anicteric cholestatic liver disease. Liver biopsy was suggestive of progressive familial intrahepatic cholestasis type 3. He showed symptomatic improvement after starting ursodeoxycholic acid and fat-soluble vitamins and is under follow up.

Propofol-ketamine and propofol-fentanyl combinations for nonanesthetist-administered sedation.

OBJECTIVES: There is a need to compare propofol requirement between propofol-ketamine (PK) and propofol-fentanyl (PF) given as nonanesthetist-administered propofol sedation during pediatric esophagogastroduodenoscopy (EGD). METHODS: The study was a parallel-group, randomized, double-blind comparison of the need for additional doses of propofol in the first minute after sedation induction between PK and PF, administered by rotating trainees in pediatrics for sedation during pediatric EGD. A total of 95 children with American Society of Anesthesiologists class I to III between 3 and 12 years undergoing EGD were included and randomized to either of the groups. After midazolam premedication, children received either 0.5 mg/kg ketamine (PK) or 1 µg/kg of fentanyl (PF) followed by a mandatory 1 mg/kg of propofol. Additional doses of propofol of 0.5 mg/kg each were given to achieve sedation induction (modified Ramsay scale level 6), and further doses were administered during the procedure as required. A total of 92 children (PK, n = 47; PF, n = 45) were analyzed. P < 0.05 was considered significant. RESULTS: There was no difference in the propofol dose required for successful scope introduction and also in the need for additional propofol doses and the total additional propofol doses required in the first minute after sedation induction. Propofol injection pain was higher in the PF group (odds ratio 1.78). The adverse events and recovery time were similar. There was no escalation of care, airway intubations, death, or disability. CONCLUSIONS: Nonanesthetist-administered propofol sedation is feasible in teaching hospitals. Propofol requirement is similar in both PK and PF combination regimens, but the lower frequency of propofol injection pain may favor the use of PK.

Intraperitoneal transplant of Hepatocytes co-Encapsulated with mesenchymal stromal cells in modified alginate microbeads for the treatment of acute Liver failure in Pediatric patients (HELP)-An open-label, single-arm Simon's two stage phase 1 study protocol.

BACKGROUND: Pediatric acute liver failure (PALF) carries a high mortality without liver transplantation (LT) in children. Liver transplantation, though lifesaving, is limited by timely donor organ availability, the risks of major surgery and complications of life-long immunosuppression. Hepatocyte transplantation (HT) improves synthetic and detoxification functions in small animal models. The encapsulation of hepatocytes in alginate protects it from the recipient immune system while the intraperitoneal route of administration allows large volumes to be infused. The safety and possibly short-term efficacy of encapsulated hepatocytes has been observed in a named patient use. A novel type of microbeads (HMB002) has been developed, using a modified alginate and mesenchymal stromal cells (MSCs). Its safety and medium-term efficacy need to be studied in the context of clinical study while optimizing the hepatocyte function and viability using modifications of the alginate and MSCs co-encapsulation. METHODS: A single centre, non-randomised, open-label, single-arm Simon's two stage study will be conducted to evaluate the safety, biological activity and tolerability of transplantation of a single intraperitoneal dose of microbeads made from an optimum combination of a modified alginate, MSCs and hepatocytes in 17 patients less than 16 years of age with acute liver failure (Stage 1: 9 patients and Stage 2: 8 patient). Safety will be assessed by documenting moderate to severe (including life threatening and death) adverse events due to HMB002 in the first 52 weeks post-procedure. Tolerability will be assessed by observing the proportion of initiated infusions where >80% of infusion is received by the patient. Biological activity will be reflected in patient survival with native liver at 24 weeks post treatment. DISCUSSION: HMB002, if safe and efficacious in acute liver failure, could be a bridge until the liver regenerates or a suitable organ becomes available. There are multiple advantages to using HT. HT, when delivered by the intraperitoneal route, is less invasive than LT. Hepatocytes from a single donor liver can be used to treat multiple patients. Cryopreserved cells provide an off-the-shelf emergency treatment in PALF. When encapsulated, alginate encapsulation of hepatocytes precludes the need for immunosuppression unlike in LT.

Acute on chronic liver disease in children from the developing world: recognition and prognosis.

OBJECTIVES: A subset of children with chronic liver disease (CLD) decompensate following an acute insult; however, data for children are not readily available. The present study aims to characterize the clinical presentation, etiology, outcome, and determinants of short-term mortality in children with an acute hepatic insult superimposed over CLD. PATIENTS AND METHODS: Children of acute on chronic liver disease (ACLD) were grouped as acute on chronic liver failure (ACLF) and non-ACLF. ACLF was defined as per the definition proposed by Asian Pacific Association for the Study of Liver. The acute insult, etiology of CLD, and clinical and laboratory parameters at admission along with 3-month outcome were assessed. Receiver operating curve (ROC) was plotted to measure the performance of pediatric end-stage liver disease (PELD) score in predicting the 3-month mortality. RESULTS: Of the 36 children with ACLD (median age 9.5; range 3-15 years), 17 fulfilled ACLF criteria and 19 non-ACLF. CLD was diagnosed for the first time in 86% children during their presentation with a superimposed acute insult. Wilson disease and autoimmune liver disease were the most common underlying etiology. Acute insult was caused by hepatitis E virus (HEV) in 27 (75%) children and hepatitis A virus (HAV) in 10 (28%). The 3-month mortality of ACLF group was significantly higher than that of non-ACLF group (59% vs 11%, P = 0.001). PELD score of >25.5 predicted death, with a sensitivity of 100% and specificity of 83.3%. CONCLUSIONS: Superinfection with hepatotropic viruses on CLD in children manifests as ACLD: ACLF and non-ACLF. Hepatitis E virus is the most common superinfection in the population studied. The mortality in ACLF is 5 times higher than that in the non-ACLF group. PELD score is useful in differentiating likely survivors and nonsurvivors.

Biliary Atresia Screening in India-Strategies and Challenges in Implementation.

OBJECTIVE: To assess the utilization of SCC implemented in southern India and the effect on SCC utilization of face-to-face verbal education versus video-based content delivery. METHODS: The study included newborns with postnatal age of less than 2 wk at discharge. Mothers were administered SCCs and provided standardized verbal or video health education based on the time-period of enrollment. Home based monitoring of stool color and return of SCC on postnatal day 21 was advised. Telephone surveys were conducted to identify SCC use among families that did not return the SCC by post. RESULTS: Of the 2254 newborns enrolled, 1130 were in the verbal-counseling group and 1124 in the video-counseling group. No newborns with pale stools and biliary atresia were identified. SCC return rates were 3.8% and 2.8%. Comparing the verbal and video-counseling groups, there were no differences in the conservative (81.8% vs. 81.5%) and optimistic estimates (97.1% vs. 97.3%) of SCC utilization rates. Mothers with better educational status had higher optimistic estimates of SCC utilization. CONCLUSIONS: The use of a validated SCC in Tamil with standardized information delivery leads to good utilization rates in southern India, with video content delivery being as effective as face-to-face verbal content delivery. SCC return by post is not a feasible mode of identification of card use. TRIAL REGISTRATION: The study is registered under Clinical Trials Registry - India (CTRI/2018/01/011285).

Splenic stiffness and platelet count to predict varices needing treatment in pediatric extrahepatic portal vein obstruction.

BACKGROUND: Surveillance endoscopy to detect varices needing treatment (VNT) is important to prevent bleeding and morbidity in portal hypertension. In adult and pediatric cirrhosis, platelet count and liver stiffness measurement (LSM) are useful in selecting patients for endoscopy. Such recommendations do not exist for extrahepatic portal vein obstruction (EHPVO). Splenic stiffness measurement (SSM) has been studied in adult and pediatric EHPVO with conflicting results and methodological errors. This study evaluates the role of platelet counts and SSM to predict VNT and bleeding in pediatric EHPVO while comparing LSM and SSM between pediatric EHPVO and controls. METHODS: One hundred and seven children (55 with EHPVO and 52 controls) were recruited. Clinical, biochemical, hematological, and radiographic parameters of all children were noted. All children with EHPVO underwent endoscopy. RESULTS: Of the 55 children with EHPVO, 48 (87.3%) had VNT. There was no difference in the platelet counts (85,000/mm3 vs. 120,000/mm3, p = 0.58) and SSM (3.62 vs. 3.19, p = 0.05) between EHPVO children with VNT and those without. They had poor sensitivity and specificity to predict VNT. EHPVO children with bleeding had higher SSM that those without. LSM was higher among EHPVO than among controls (1.19 vs. 1.10, p = 0.003). Those with LSM higher than controls had normal liver histology. CONCLUSION: SSM is higher in EHPVO bleeders but SSM and platelet counts are unreliable to predict VNT in pediatric EHPVO. Surveillance endoscopies may be needed in all pediatric EHPVO until better screening strategies are available. TRIAL REGISTRATION: Not applicable.

Evaluation of LAMP for detection of Shigella from stool samples in children.

BACKGROUND: To assess the diagnostic accuracy of loop-mediated isothermal amplification (LAMP) for the detection of Shigella from stool samples from children. METHODS: Consecutive stool samples from children aged <13 years old who presented with acute watery diarrhoea or dysentery to the Department of Paediatrics were collected and processed in the Department of Microbiology. All the stool samples were subjected to culture, conventional PCR and LAMP. Genomic sequencing was performed for samples that were positive by LAMP but negative by both culture and conventional PCR. The LAMP results were compared to those from culture and to a composite reference standard based on culture and conventional PCR. RESULTS: Amongst the 374 stool samples tested, 291 samples were positive by LAMP and 213 were positive by the composite reference standard. The sensitivity of LAMP was 100 % (98.3-100 %) and its specificity was 51.6 % (43.6-59.5 %) with a disease prevalence of 57 %. The sensitivity and specificity of LAMP improved to 99.3 % (94.2-100) and 98.2 % (94.5-99.9), respectively, using latent class analysis, while assuming that genomic sequencing has perfect specificity. DISCUSSION: The authors have standardized the LAMP procedure for direct application to clinical stool samples. LAMP is a sensitive and specific method for the diagnosis of Shigella from stool samples of children as compared to both culture and conventional PCR.