Objectives and Study

Primary sclerosing cholangitis (PSC) is a poorly understood cholangiopathy. Here we aimed to characterize extra hepatic biliary tree of Mdr2^-/- mice and evaluate if the injury can be repaired with N-Acetyl-L-Cysteine (L-NAC), an antioxidant and glutathione precursor.

Methods

We histologically characterized the extra hepatic biliary tree of Mdr2^-/- mice. Extrahepatic bile ducts (EHBDs) fwere incubated ex-vivo with or without the addition of 5µM L-NAC and stained for various markers. We supplemented the drinking water with L-NAC, and assessed liver and EHBD response by histology and serum liver enzymes level. We combined local L-NAC treatment in a whole animal model via bile duct catheters into the gallbladders, and injected the mice twice a day with 50µM L-NAC.

Results

Mdr2^-/- mice developed progressive EHBD injury over time. Ex-vivo local L-NAC treatment significantly improved EHBD morphology both at 2 and 16 weeks of age with improvement in lumen shape and nuclear crowding. Tight junctions which are already impaired at 2 weeks of age, as noted by absence of ZO-1 stain compared to WT were restored with L-NAC treatment at 2 weeks old Mdr2^-/- EHBDs but not 16 weeks old, in addition to reduction in Vimentin levels. Interestingly, Mdr2^-/- mice treated with L-NAC added to their drinking water, showed significant improvement in liver enzymes levels, along with substantial reduction in intrahepatic periductal fibrosis, although the EHBD remained injured. Combining local L-NAC treatment in a whole animal using bile duct catheter resulted with significant improvement in liver enzyme along with EHBD recovery.

Conclusions

Mdr2^-/- mice have progressive EHBD disease mimicking human PSC EHBD disease. Injured EHBD have a potential for recovery, mainly at early stages of injury. Oral administration of L-NAC has a mild effect on liver injury, though limited effect on EHBD; Local L-NAC treatment using bile duct catheters resulted in both biochemical improvement and EHBD recovery.

Objectives and Study

Ascites in children is multifactorial and high serum ascites albumin gradient (SSAG ≥1.1) is used to differentiate portal hypertension (PHT) related ascites from non-PHT causes. We evaluated the age-based etiology and the diagnostic accuracy of SAAG in children with ascites.

Methods

Children with all grades of ascites were retrospectively evaluated. Etiological diagnosis was based on clinical presentation and investigations. All cases with ascitic fluid analysis and a definite diagnosis were included for calculating the utility of SAAG.

Results

A total of 878 children (568[64.7%] boys) with ascites were enrolled. The majority were liver disease related (638 [72.7%], age 96[3-288] months) and secondary to acute viral hepatitis [98,15.4%], acute liver failure [185,29%], chronic liver disease [276,43.3%] and Budd-Chiari syndrome [79,12.4%]. Other causes included tubercular (46, 5.2%), pancreatic (32, 3.6%), chylous (20, 2.3%), biliary (12,1.4%), pseudoascites (16,1.8%), tropical infections (46, 5.2%), nephrotic (26, 2.9 %), malignancy (23,2.6%), cardiac (9,1.0%), protein losing enteropathy (4, 0.4%) and others (6,0.6 %). Etiology in younger (≤5y) vs older children is shown in Figure 1. Biliary and pseudoascites were more frequent in younger and tubercular ascites in older children.

Ascitic fluid analysis was available in 497 cases (394[79.2%] PHT related and 103[20.7%] non-PHT ascites). SAAG (≥1.1) correctly differentiated PHT and non-PHT ascites in 89.7% cases, with a sensitivity 95.5% (95%CI- 92.9-97.3%), specificity 93.0% (85.4-97.4%), PPV 98.3% (96.5- 99.2%), NPV 82.4% (74.6-88.2%), and diagnostic accuracy of 95.1% (92.7-96.8%). Reasons for inaccurate SAAG included mixed ascites (n-11), serum albumin ≤ 1.1g/dl (n-4), different day serum and ascitic-fluid albumin estimation (n-7), albumin infusion (n-1), chylous ascites (n-3), hypergammaglobulinemia (n-2) and unexplained (n-23).

Conclusions

Nearly 27% children have non-PHT related ascites. SAAG has a good diagnostic accuracy of 95% in differentiating PHT from non-PHT ascites. Knowledge about factors affecting SAAG and complete ascitic fluid analysis is helpful.

Objectives and Study

We report various clinical phenotypes and genotypes of 25 Saudi children affected by homozygous TJP2 variants inducing familial hypercholanemia or subtypes of progressive familial intrahepatic cholestasis (PFIC4).

Methods

We conducted a retrospective study to identify all patients who were diagnosed with TJP2 disease in 2 tertiary care centers from 2000 to 2022.

Results

We have diagnosed 25 children with TJP 2 disease from 15 Saudi families (13 males). All the 25 cases developed low/normal GGT infantile cholestasis. We have identified 12 biallelic homozygous mutations in TJP2 (7 are novel). Eleven of the 12 variants (one splicing, 5 frameshift, 5 nonsense) were associated with progression to end stage liver disease leading to liver transplantation or death by 1 to 6 years of age. The remaining missense variant was associated with a milder clinical phenotype, survival into late childhood with normal liver function tests. There were two distinctive histopathological patterns: 1) a “non-inflammatory phenotype” characterized by few or no giant cell transformation with or without thin fibrotic bands, bland cholestasis, and absence of lobular disarray on liver biopsy, accompanied with mildly elevated transaminases (similar to PFIC 1); 2) an “inflammatory phenotype” characterized by marked giant cell transformation, lobular disarray, and portal fibrosis on liver biopsy accompanied with marked elevation of transaminases, (similar to PFIC 2). The latest phenotype was associated extrahepatic manifestations in 10 of the 25 cases (40%) including deafness, cardiac, neurologic, pulmonary, and renal lesions.

Conclusions

The results of our study provide further evidence of the broad allelic heterogeneity of the TJP2 defect leading to a phenotypic continuum between mild, transient, non-progressive disease and rapidly progressive, fatal, early-onset disease phenotypes. Our data show a genotype-phenotype correlation with splicing, frameshift, nonsense TJP2 variants associated with severe phenotype and the missense variant associated with milder phenotype.