Genotype correlates with clinical course and outcome of children with tight junction protein 2 (TJP2) deficiency-related cholestasis

BACKGROUND AND AIMS

The study aimed to describe the clinical course and outcomes, and analyze the genotype-phenotype correlation in patients with tight junction protein 2 (TJP2) deficiency.

APPROACH AND RESULTS

Data from all children with chronic cholestasis and either homozygous or compound heterozygous mutations in TJP2 were extracted and analyzed. The patients were categorized into 3 genotypes: TJP2-A (missense mutations on both alleles), TJP2-B (missense mutation on one allele and a predicted protein-truncating mutation [PPTM] on the other), and TJP2-C (PPTMs on both alleles). A total of 278 cases of genetic intrahepatic cholestasis were studied, with TJP2 deficiency accounting for 44 cases (15.8%). Of these, 29 were homozygous and 15 were compound heterozygous variants of TJP2 . TJP2-A genotype was identified in 21 (47.7%), TJP2-B in 7 cases (15.9%), and TJP2-C in 16 cases (36.4%), respectively. Patients with the TJP2-C genotype were more likely to experience early infantile cholestasis (87.5% vs. 53.5%, p =0.033), less likely to clear jaundice (12.5% vs. 52.2%, p =0.037), more likely to develop ascites, and had higher serum bile acids. Patients with the TJP2-C genotype were more likely to die or require liver transplantation (native liver survival: 12.5% vs. 78.6%, p <0.001), with a median age at death/liver transplantation of 2.5 years. Cox regression analysis revealed that TJP2-C mutations ( p =0.003) and failure to resolve jaundice ( p =0.049) were independent predictors of poor outcomes.

CONCLUSIONS

Patients with the TJP2-C genotype carrying PPTMs in both alleles had a rapidly progressive course, leading to early decompensation and death if they did not receive timely liver transplantation.

A novel, bedside, etiology specific prognostic model (Peds-HAV) in hepatitis A induced pediatric acute liver failure

BACKGROUND

Hepatitis A virus (HAV) is the commonest cause of pediatric acute liver failure (PALF) in developing countries. Our objective was to develop and validate a HAV-etiology specific prognostic model in PALF.

METHODS

All children with HAV induced PALF (IgM HAV reactive) were included. Outcome was defined at day 28. Only those with death or native liver survival were included. The model (Peds-HAV) was derived using the independent predictors of outcome and validated in a prospective independent cohort.

RESULTS

Hepatitis A accounted for 131 (45.9%) of total 285 PALF. After excluding 11 children who underwent liver transplant, 120 children (74 survivors and 46 death) were included. The first 75 patients formed the derivation cohort and the next 45 patients formed the prospective validation cohort. In the derivation cohort, INR: OR 2.208, (95% CI 1.321-3.690), p = 0.003, grade of hepatic encephalopathy (HE): OR 3.078, (95% CI 1.017-9.312), p = 0.047 and jaundice-to-HE interval: OR 1.171, (95% CI 1.044-1.314), p = 0.007 were independent predictors of death. The final model comprised three criteria: (1) presence of grade 3-4 HE, (2) INR greater than 3.1, and (3) jaundice to HE interval more than 10 days. Presence of 2 or more of these criteria predicted death with 90% sensitivity, 81.4% specificity and 84.9% accuracy. Peds-HAV model was superior to existing prognostic models. In the validation cohort, Peds-HAV model predicted death with 83.3% sensitivity and 92.6% specificity.

CONCLUSION

Peds-HAV model is a simple, bedside, dynamic, etiology (HAV) specific prognostic model based on 3 objective parameters with optimum sensitivity and specificity, hence should be used as liver transplant listing criteria in HAV induced PALF.

Efficacy and Safety of Sodium Benzoate in The Management of Hyperammonemia in Decompensated Chronic Liver Disease of the Childhood-A Double-blind Randomized Controlled Trial

OBJECTIVE

The objective was to evaluate the efficacy and safety of sodium benzoate in the management of hyperammonemia and hepatic encephalopathy (HE) in decompensated chronic liver disease.

METHODS

It was a prospective, interventional, double-blinded randomized controlled trial conducted from August 2017 to December 2018. Children with decompensated chronic liver disease and hyperammonemia were included in the study. Those with ammonia >400 μg/dL, already receiving sodium benzoate or with grade III ascites were excluded. Group A received sodium benzoate (400 mg/kg loading dose followed by 200 mg · kg · daymaintenance for 5 days) along with the standard medical therapy. Group B received standard medical therapy with placebo.

RESULTS

A total of 108 episodes of hyperammonemia occurred in 86 patients of whom 16 were excluded. The final analysis included 46 episodes in each group. The median decrease in ammonia from baseline to day 5 was 52 μg/dL in group A versus 42 μg/dL in group B (P = 0.321). There was a significant decrease in ammonia on days 1 and 2 in group A as compared to group B, but not on subsequent days. There was no significant difference in the resolution of HE (57.1% vs 50%; P = 1), but there was higher, albeit insignificant increase in ascites in group A (15.9% vs 4.5%).

CONCLUSIONS

Addition of sodium benzoate significantly reduced the ammonia levels on the first 2 days of therapy but the effect was not sustained till day 5. The effect of sodium benzoate would probably be more sustained, if higher dosage (400 mg · kg · day) could be used under monitoring of benzoate levels. There was no effect on resolution of HE. Sodium benzoate caused an increasing trend of adverse events with no effect on short-term survival.