OBJECTIVE: Mechanisms and clinical impact of portal microthrombosis featuring severe COVID-19 are unknown. Intrapulmonary vascular dilation (IPVD)-related hypoxia has been described in severe liver diseases. We hypothesized that portal microthrombosis is associated with IPVD and fatal respiratory failure in COVID-19.
METHODS: Ninety-three patients who died from COVID-19, were analysed for portal microvascular damage (histology), IPVD (histology and chest-computed tomography, CT), and hypoxemia (arterial blood gas). Seventeen patients who died from COVID-19-unrelated pneumonia served as controls. Vascular lesions and microthrombi were phenotyped for endothelial (vWF) and pericyte (αSMA/PDGFR-β) markers, tissue factor (TF), viral spike-protein and nucleoprotein (SP, NP), fibrinogen, platelets (CD41a). Viral particles in vascular cells were assessed by transmission electron microscopy (TEM). Cultured pericytes were infected with SARS-CoV-2 to measure TF expression and tubulisation of human pulmonary microvascular endothelial cells (HPMEC) was assessed upon vWF treatment.
RESULTS: IPVD was present in 16/66 COVID-19 patients with both liver and lung histology, with a younger age (62 vs 78yo), longer illness (25 vs 14 days), worsening hypoxemia (PaO2/FiO2 from 209 to 89), and more ventilatory support (63 vs 22%) compared to COVID-19/Non-IPVD. IPVD, absent in controls, were confirmed by chest-CT. COVID-19/IPVD liver histology showed portal microthrombosis in >82.5% of portal areas, with a thicker wall of αSMA/PDGFR-β+/ SP+/NP+ pericytes compared with COVID-19/Non-IPVD. Thrombosed portal venules correlated with αSMA+ area, whereas infected SP+/NP+ pericytes expressed TF. SARS-CoV-2 viral particles were observed in portal pericytes. In-vitro SARS-CoV-2 infection of pericytes up-regulated TF and induced endothelial cells to overexpress vWF, which expanded HPMEC tubules.
CONCLUSIONS: SARS-CoV-2 infection of liver pericytes elicits a local procoagulant response associated with extensive portal microthrombosis, IPVD and worsening respiratory failure in fatal COVID-19.
UNASSIGNED: Vascular involvement of the liver represents a serious complication of COVID-19 infection that must be considered in the work-up of patients with long-lasting and progressively worsening respiratory failure, as it may associate with the development of intrapulmonary vascular dilations. This clinical picture is associated with a pro-coagulant phenotype of portal venule pericytes, which is induced by SARS-CoV-2 infection of pericytes. Both observations provide a model that may apply, at least in part, to other vascular disorders of the liver, featuring obliterative portal venopathy, similarly characterized at the clinical level by development of hypoxemia and at the histological level, by phlebosclerosis and reduced caliber of the portal vein branches in the absence of cirrhosis. Moreover, our findings bring light to an as yet overlooked player of thrombosis pathophysiology, i.e. pericytes, which may provide novel therapeutic tools to halt prothrombotic mechanisms.

The use of extended criteria donors (ECD) in liver transplantation is increasing due to the organ shortage. Histological evaluation of the liver graft in the context of procurement is an important tool for extending the donor pool without affecting the quality of the transplanted organs. Macrovesicular steatosis is widely accepted as predictor of early allograft dysfunction (EAD), while other features, such as portal fibrosis, are poorly studied.
To identify morphological features, other than macrovesicular steatosis, that may affect recipients\' outcome.
Between 2014 and 2016, 132 donors with extended criteria underwent pre-transplant liver biopsy during procurement. Histological variables of the graft, donors\'/recipients\' clinical data, EAD and patient/graft survival were registered.
The recipients who received a graft with histological-proven portal fibrosis had a significant lower patient and graft survival in comparison to patients without fibrosis (P = 0.044 and P = 0.039, respectively). Donors\' dyslipidemia was significantly associated with the occurrence of EAD (P = 0.021). When dyslipidemia was combined with histological liver fibrosis a 54.5% incidence of EAD was observed (P = 0.012).
The histological assessment of liver fibrosis in pre-transplant biopsy of ECD grafts, together with donor\'s clinical data, provides important information on recipients\' outcome.

Recent evidence has implicated EFL1 in a phenotype overlapping Shwachman-Diamond syndrome (SDS), with the functional interplay between EFL1 and the previously known causative gene SBDS accounting for the similarity in clinical features. Relatively little is known about the phenotypes associated with pathogenic variants in the EFL1 gene, but the initial indication was that phenotypes may be more severe, when compared with SDS. We report a pediatric patient who presented with a metaphyseal dysplasia and was found to have biallelic variants in EFL1 on reanalysis of trio whole-exome sequencing data. The variant had not been initially reported because of the research laboratory\'s focus on de novo variants. Subsequent phenotyping revealed variability in her manifestations. Although her metaphyseal abnormalities were more severe than in the original reported cohort with EFL1 variants, the bone marrow abnormalities were generally mild, and there was equivocal evidence for pancreatic insufficiency. Despite the limited number of reported patients, variants in EFL1 appear to cause a broader spectrum of symptoms that overlap with those seen in SDS. Our report adds to the evidence of EFL1 being associated with an SDS-like phenotype and provides information adding to our understanding of the phenotypic variability of this disorder. Our report also highlights the value of exome data reanalysis when a diagnosis is not initially apparent.

BACKGROUND: Extrahepatic biliary atresia is a progressive disorder characterised by fibroinflammatory obliteration or stenosis of the extrahepatic biliary tree leading to obstruction of bile flow and cholestatic jaundice. It is the most common cause for cholestasis in newborn. Histopathological criteria for diagnosing biliary atresia from liver biopsy have not been clearly defined.
OBJECTIVE: This study was undertaken to analyse the significance of the various histopathological features in diagnosis and prognosis of extrahepatic biliary atresia from liver biopsy specimens.
METHODS: This was a retrospective study of 43 cases of extra-hepatic biliary atresia diagnosed and treated at a tertiary care hospital between January 2010 to December 2014. Formalin fixed paraffin embedded liver biopsy tissues were processed by standard technique and the slides were stained with haematoxylin and eosin. All the slides were reviewed and graded by a semi-quantitative scoring system. Features such as increased age at kasai\'s portoenterostomy, portal fibrosis, bile duct proliferation, cholestasis, portal inflammation and duct plate malformation were studied. Statistical analysis was worked out using SPSS 17.0 (statistical package for the social science software). Chi-square test was used to find association between various parameters with respect to mortality and Kaplan-Meier estimator was used for survival analysis of the population under study.
RESULTS: In this study comprising of 43 cases, only 6 cases (13.95%) were alive at the end of 6 months follow-up. Twenty patients who died and the 17 cases with poor survival had greater degrees of fibrosis, bile duct proliferation and cholestasis. Majority of the cases with duct plate malformation expired inspite of earlier surgical intervention. Thus proving the association of fibrosis, bile duct proliferation, cholestasis and duct plate malformation with the survival and prognosis of biliary atresia cases. Age at surgery did not show any correlation with prognosis as cases operated even at <60 days had poor survival.
CONCLUSIONS: From this study it can be concluded that in extrahepatic biliary atresia patients, presence of duct plate malformation, greater degrees of fibrosis, bile duct proliferation and cholestasis were strongly associated with poor prognosis.

The molecular mechanisms underlying progressive liver fibrosis following surgical treatment of biliary atresia (BA) remain unclear. Our aim was to address hepatic gene and protein expression and serum levels of matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) after successful portoenterostomy (PE), and relate them to histological signs of liver injury, clinical follow-up data and biochemical markers of hepatic function. LIver biopsies and serum samples were obtained from 25 children after successful PE at median age of 3.3 years. Serum MMP concentrations were determined by enzyme-linked immune sorbent assay. Hepatic gene expression of MMPs and TIMPs was analyzed using real-time reverse-transcription PCR. Liver expression of MMP-7 and cytokeratin-7 was studied using immunohistochemistry. Despite effective clearance of biochemical and histological cholestasis following PE, BA patients showed increased hepatic gene expression of MMP-7 (29-fold, p < 0.001), MMP-2 (3.1-fold, p < 0.001), MMP-14 (1.7-fold, p = 0.007), and TIMP-1 (1.8-fold, p < 0.001), when compared to controls. Similar to a biliary epithelial marker cytokeratin-7, expression of MMP-7 localized in biliary epithelium of bile ducts and ductal proliferations and periportal hepatocytes and was increased (p < 0.001) in relation to controls. BA patients had 6-fold higher serum levels of MMP-7 (p < 0.001), which correlated positively with hepatic MMP-7 gene (r = 0.548, p = 0.007) and protein (r = 0.532, p = 0.007) expression. Patients showed a positive correlation between biliary MMP-7 expression and Metavir fibrosis stage (r = 0.605, p = 0.001) and portal fibrosis grade (r = 0.606, p = 0.001). Neither similarly increased MMP-7 expression nor correlation with liver fibrosis was observed in patients with intestinal failure-associated liver disease and comparable Metavir stage. In conclusion, our findings support an unique role of altered hepatic expression of MMP-7 in the progression of liver fibrosis after successful PE and introduce a potential therapeutic target to pharmacologically extend native liver survival by inhibiting MMP-7 hyperactivity. Serum MMP-7 may be a valuable postoperative prognostic tool in BA.

OBJECTIVE: Precisely what type of cells mainly contributes to portal fibrosis, especially in chronic viral hepatitis, such as hepatic stellate cells (HSCs) in the parenchyma or myofibroblasts in the portal area, still remains unclear. It is necessary to clarify the characteristics of cells that contribute to portal fibrosis in order to determine the mechanism of portal fibrogenesis and to develop a therapeutic target for portal fibrosis. This study was undertaken to examine whether LRAT+/CRBP-1+ HSCs contribute to portal fibrosis on viral hepatitis.
METHODS: Antibodies to lecithin:retinol acyltransferase (LRAT), cellular retinol-binding protein-1 (CRBP-1) and widely ascertained antibodies to HSCs (alpha-smooth muscle actin, neurotrophin-3) and endothelial cells (CD31) were used for immunohistochemical studies to assess the distribution of cells that contribute to the development of portal fibrosis with the aid of fluorescence microscopy. A quantitative analysis of LRAT+/CRBP-1+ HSCs was performed.
RESULTS: The number of LRAT+/CRBP-1+ HSCs was increased in fibrotic liver in comparison with normal liver in the portal area and fibrous septa. The number of double positive cells was less than 20% of all cells/field in maximum.
CONCLUSIONS: This study provides evidence that functional HSCs coexpressing both LRAT and CRBP-1 that continue to maintain the ability to store vitamin A contribute in part to the development of portal fibrogenesis in addition to parenchymal fibrogenesis in patients with viral hepatitis.

Hematologic, neurologic, renal, and rheumatic complications in patients with cyanotic congenital heart disease are well known. However, the effects of this condition on the liver are poorly described. Between April 2005 and April 2010, 25 adults with cyanotic congenital heart disease were studied to determine clinical history, liver ultrasonographic data, and liver histological presentation. Twenty-five patients, with a median age of 28.7 ± 8.3 years and a basal tissue hemoglobin oxygen saturation of 83.3% ± 6.8%, were studied. Liver ultrasonographic examination showed abnormalities in 10 of 20 patients (50%): 6 patients (30%) had hepatomegaly, 2 patients (10%) heterogeneous parenchyma echo pattern, and 2 patients (10%) increased portal echogenicity. Ascites was found in 7 patients (28%): 4 patients had refractory ascites and 3 patients anasarca. Patients with anasarca responded well to oral and intravenous furosemide, but those with isolated ascites did not. No data to indicate severe ventricular dysfunction or severe valve regurgitation were seen. In patients with refractory ascites who had therapeutic paracentesis, serum-ascites albumin gradient in ascites was greater than 1.1 g/dL. No significant association was found between patients with or without ascites when laboratory data and New York Heart Association functional class were compared. Liver biopsy was performed in 6 patients (24%). The most remarkable liver histological finding, in those with refractory ascites, was the existence of periportal fibrosis associated with sinusoidal dilatation. Periportal liver fibrosis associated with congestive heart failure, sepsis, or a long-term Fontan procedure can trigger refractory ascites formation.

BACKGROUND: That non-cirrhotic portal fibrosis (NCPF) can lead to end stage chronic liver disease (CLD) has been convincingly demonstrated only recently after the study of explant livers from clinically cirrhosis cases.
OBJECTIVE: This study attempted to determine the frequency of NCPF among adults transplanted for end stage CLD and to identify parameters for a pre-transplant diagnosis of NCPF.
METHODS: Several parameters were analyzed in three categories of cases: pure NCPF (n = 10), overlap NCPF (n = 10), and NAFLD cirrhosis controls (n = 44). Morphologic features of NCPF were looked for in explant livers of all these.
RESULTS: Explant livers in the pure NCPF group were non-cirrhotic and showed histologic features of NCPF. These features were also present in all cases of overlap NCPF in the background of established cirrhosis of other etiologies but absent in the NAFLD cirrhosis controls. Values of seven objective and two subjective parameters showed significant differences between pure NCPF and NAFLD control groups. Compared to NAFLD controls, the model for end stage liver disease (MELD) score, body mass index (BMI), bilirubin, albumin, aspartate amino transferase (AST), and international normalized ratio (INR) were significantly less, whereas variceal grade was higher in the pure NCPF group.
CONCLUSIONS: The study concludes that in our population, NCPF constitutes about 5% of the subset of end stage CLD considered eligible for liver transplantation (LT), presenting mostly as cryptogenic cirrhosis (CC). A diagnosis of NCPF should be considered when patients presumed to have cryptogenic or other cirrhosis become eligible for LT even in the presence of relatively well-preserved liver function and low MELD scores. End stage CLD manifests at earlier age, when cirrhosis of another etiology supervenes on pre-existent NCPF.