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Background: Fecal calprotectin (FCP) is a highly sensitive biomarker of intestinal inflammation widely used in diagnostics and monitoring of inflammatory bowel disease (IBD). Immunohistochemical assessment of calprotectin in the bowel mucosa is not a diagnostic standard. Therefore, the aim of this study was to evaluate tissue calprotectin (TCP) as a potential marker providing added insight for pediatric patients with Crohn’s disease (CD). Methods: Fecal and tissue calprotectin were measured in children with CD. The values were correlated with disease activity and histopathological changes of the patients’ endoscopic biopsies. Disease activity was assessed using the Pediatric Crohn’s Disease Activity Index (PCDAI); fecal calprotectin (FCP) was measured with the ELISA test. Immunohistochemical (IHC) staining for calprotectin antigen was performed on the biopsy samples from six bowel segments, and the number of TCP cells was counted per high power field (HPF). Non-parametric statistical tests were used for data analysis. Results: Fifty-seven children with CD with a median age of 10.5 (1–17) years (yrs) were examined for fecal and tissue calprotectin. The patients’ median PCDAI score was 10 (0–63.5), while median FCP was 535 (30–600) μg/g. We observed a correlation between disease activity (PCDAI) and FCP, TCP in inflammatory lesions and in crypts. There was no association either between FCP and TCP or between TCP in epithelium and PCDAI. Conclusion: It seems that IHC detection of calprotectin in bowel mucosa to assess disease behavior may be useful. FCP is a gold-standard biomarker in the diagnosis, monitoring and prognosis of IBD, and its levels correlated well with clinical activity in our study group.

Non-alcoholic fatty liver disease (NAFLD) is a health concern affecting 24% of the population worldwide. Although the pathophysiologic mechanisms underlying disease are not fully clarified, mitochondrial dysfunction and oxidative stress are key players in disease progression. Consequently, efforts to develop more efficient pharmacologic strategies targeting mitochondria for NAFLD prevention/treatment are underway. The conjugation of caffeic acid anti-oxidant moiety with an alkyl linker and a triphenylphosphonium cation (TPP+), guided by structure-activity relationships, led to the development of a mitochondria-targeted anti-oxidant (AntiOxCIN4) with remarkable anti-oxidant properties. Recently, we described that AntiOxCIN4 improved mitochondrial function, upregulated anti-oxidant defense systems, and cellular quality control mechanisms (mitophagy/autophagy) via activation of the Nrf2/Keap1 pathway, preventing fatty acid-induced cell damage. Despite the data obtained, AntiOxCIN4 effects on cellular and mitochondrial energy metabolism in vivo were not studied.In the present work, we proposed that AntiOxCIN4 (2.5 mg/day/animal) may prevent non-alcoholic fatty liver (NAFL) phenotype development in a C57BL/6J mice fed with 30% high-fat, 30% high-sucrose diet for 16 weeks. HepG2 cells treated with AntiOxCIN4 (100 μM, 48 h) before the exposure to supraphysiologic free fatty acids (FFAs) (250 μM, 24 h) were used for complementary studies. AntiOxCIN4 decreased body (by 43%), liver weight (by 39%), and plasma hepatocyte damage markers in WD-fed mice. Hepatic-related parameters associated with a reduction of fat liver accumulation (by 600%) and the remodeling of fatty acyl chain composition compared with the WD-fed group were improved. Data from human HepG2 cells confirmed that a reduction of lipid droplets size and number can be a result from AntiOxCIN4-induced stimulation of fatty acid oxidation and mitochondrial OXPHOS remodeling. In WD-fed mice, AntiOxCIN4 also induced a hepatic metabolism remodeling by upregulating mitochondrial OXPHOS, anti-oxidant defense system and phospholipid membrane composition, which is mediated by the PGC-1α-SIRT3 axis. AntiOxCIN4 prevented lipid accumulation-driven autophagic flux impairment, by increasing lysosomal proteolytic capacity.AntiOxCIN4 improved NAFL phenotype of WD-fed mice, via three main mechanisms: a) increase mitochondrial function (fatty acid oxidation); b) stimulation anti-oxidant defense system (enzymatic and non-enzymatic) and; c) prevent the impairment in autophagy. Together, the findings support the potential use of AntiOxCIN4 in the prevention/treatment of NAFLD.

The progression of non-alcoholic fatty liver (NAFL) into non-alcoholic steatohepatitis implicates multiple mechanisms, chief of which is mitochondrial dysfunction. However, the sequence of events underlying mitochondrial failure are still poorly clarified. In this work, male C57BL/6J mice were fed with a high-fat plus high-sucrose diet for 16, 20, 22, and 24 weeks to induce NAFL. Up to the 20th week, an early mitochondrial remodeling with increased OXPHOS subunits levels and higher mitochondrial respiration occurred. Interestingly, a progressive loss of mitochondrial respiration along “Western diet” feeding was identified, accompanied by higher susceptibility to mitochondrial permeability transition pore opening. Importantly, our findings prove that mitochondrial alterations and subsequent impairment are independent of an excessive mitochondrial reactive oxygen species (ROS) generation, which was found to be progressively diminished along with disease progression. Instead, increased peroxisomal abundance and peroxisomal fatty acid oxidation-related pathway suggest that peroxisomes may contribute to hepatic ROS generation and oxidative damage, which may accelerate hepatic injury and disease progression. We show here for the first time the sequential events of mitochondrial alterations involved in non-alcoholic fatty liver disease (NAFLD) progression and demonstrate that mitochondrial ROS are not one of the first hits that cause NAFLD progression.

The significance of the Quilty effect (QE) is not fully understood. It was once proposed to be related to acute cellular rejection (ACR). We aim to assess the relation between QE prevalence and antibody-mediated rejection (AMR). One thousand three hundred and fifty endomyocardial biopsies (EMBs) from 212 patients who underwent heart transplantation in the years 2001-2013 and survived a period of 30 days after the operation were diagnosed. In all EMBs routine HE staining and additional immunohistochemical staining with polyclonal antibody against C4d were performed. Microscopic findings were classified according to the new ISHLT 2013 criteria. Patients were separated into two groups: group 1 included those with at least one pAMR1 I+ and/or pAMR2 EMB (n = 16), and group 2 included the rest of the patients (n = 196). Presence of QE with distinguishing subtypes A and B (according to the first ISHLT 1990 criteria) was assessed. One hundred and twenty one EMBs from group 1 and 1229 EMBs from group 2 were diagnosed. Quilty effect type A was found in 16 (13.2%) EMBs in group 1 and in 96 (7.8%) EMBs in group 2, p < 0.001. Quilty effect type B was diagnosed in 52 (43%) EMBs in group 1 and in 245 (20%) EMBs in group 2, p < 0.001. The QE was not present in 53 (43.8%) EMBs in group 1 and in 888 (72.2%) EMBs in group 2, p < 0.001. The relation between QE prevalence and AMR is possible as the QE is present statistically more often in EMBs of patients with C4d capillary depositions.

Nonalcoholic fatty liver disease (NAFLD) is characterized by the development of steatosis, which can ultimately compromise liver function. Mitochondria are key players in obesity-induced metabolic disorders; however, the distinct role of hypercaloric diet constituents in hepatic cellular oxidative stress and metabolism is unknown. Male mice were fed either a high-fat (HF) diet, a high-sucrose (HS) diet or a combined HF plus HS (HFHS) diet for 16 weeks. This study shows that hypercaloric diets caused steatosis; however, the HFHS diet induced severe fibrotic phenotype. At the mitochondrial level, lipidomic analysis showed an increased cardiolipin content for all tested diets. Despite this, no alterations were found in the coupling efficiency of oxidative phosphorylation and neither in mitochondrial fatty acid oxidation (FAO). Consistent with unchanged mitochondrial function, no alterations in mitochondrial-induced reactive oxygen species (ROS) and antioxidant capacity were found. In contrast, the HF and HS diets caused lipid peroxidation and provoked altered antioxidant enzyme levels/activities in liver tissue. Our work provides evidence that hepatic oxidative damage may be caused by augmented levels of peroxisomes and consequently higher peroxisomal FAO-induced ROS in the early NAFLD stage. Hepatic damage is also associated with autophagic flux impairment, which was demonstrated to be diet-type dependent. The HS diet induced a reduction in autophagosomal formation, while the HF diet reduced levels of cathepsins. The accumulation of damaged organelles could instigate hepatocyte injuries and NAFLD progression.

The aim of this study was to assess the long-term results of liver transplantation (LT) in pediatric patients with unresectable hepatoblastoma (HB) or hepatocellular carcinoma (HCC) with special reference to the risk of tumor recurrence. We retrospectively analyzed data from 46 HB and 26 HCC patients who underwent LT between 1990 and 2022. In HCC patients, we compared outcomes depending on donor type. We evaluated the impact of a number of risk factors on recurrence-free survival after LT. Estimated patient survival after 5, 10, and 15 years was 82%, 73%, and 73% in the HB group and 79%, 75%, and 75% in the HCC group, respectively (p = 0.76). In the HCC group, living donor LT (LDLT) and deceased donor LT (DDLT) provided similar patient survival (p = 0.09). Estimated recurrence-free survival in patients who had three or fewer risk factors was significantly better than in patients with more than three risk factors (p = 0.0001). Adequate patient selection is necessary when considering LT for primary liver tumors in children. The presence of more than three risk factors is associated with a very high risk of recurrence and indicates poor prognosis, whereas extrahepatic disease may be considered a contraindication for transplantation.

Progressive familial intrahepatic cholestasis (PFIC) comprises a group of rare cholestatic liver disorders of childhood that could lead to liver cirrhosis. Nowadays, the partial biliary diversion procedure is still a therapeutic option in non-cirrhotic children with PFIC1 or PFIC2 after an ineffective ursodeoxycholic acid (UDCA) therapy. However, the relevant disadvantage of the partial external biliary diversion (PEBD) is that adolescent patients could not accept a permanent stoma. In some of them, despite of good clinical and biochemical results of this procedure, the ileal exclusion (IE) procedure had to be performed many years after PEBD. Our aims were to find the most characteristic early microscopic features of the disease as well as to compare changes in the liver biopsy specimens at the time of diagnosis and long-time (more than 10 years) after a surgical procedure. We examined retrospectively 8 liver biopsies from 4 PFIC2 patients comparing the results from the first biopsies done at the time of PFIC diagnosis and the second ones, done many years after PEBD. The characteristic lobular rosette formations of hepatocytes were found in all patients at the time of diagnosis. Cholestasis was observed in each patient, but only in two of them, centrally located bile plugs were found. The majority of hepatocytes showed degenerative changes from mild to severe degree. In the follow-up biopsies, cholestasis completely disappeared in 3 patients and decreased significantly in 1 other patient. Based on Batts and Ludwig fibrosis scoring system, the liver fibrosis had resolved in two out of three patients. The formation of lobular rosettes with centrally located bile plugs and degenerative changes of hepatocytes seem to be the most characteristic microscopic features in early liver biopsies in PFIC2 patients. Partial external biliary diversion significantly improved the clinical, anthropological, biochemical as well histological outcome of the patients.

Liver transplantation has become a routine treatment for children with end stage liver failure. Recently, the long term survival of pediatric patients after liver transplantation has improved, with a life expectancy much longer than that of adult recipients, but also with longer exposition of the graft to various injuries, including immunological, inflammatory and others. Biochemical tests, although important, do not always reflect graft injury. The aim of our study was to analyze the histopathology of the graft in late protocol biopsies and correlate it with the clinical and biochemical status of these patients. We analyzed 61 protocol liver biopsies taken from 61 patients. Biopsies were taken 9.03–17.09 years (mean 12.68, median 11.74 years) after transplantation. Liver specimens were examined particularly for the presence and stage of liver fibrosis, inflammation, steatosis, and acute or chronic cellular and humoral rejection. We did not find any abnormalities in 26 (42.6%) liver specimens. None of the patients had signs of cellular or antibody mediated rejection or chronic rejection. In 23 liver biopsies (37.7%), we found non-specific lymphoid infiltrates. Another problem was fibrosis (equal to or more than three on the Ishak scale)—we found it in 17 patients, including seven liver specimens (11.5%) with severe fibrosis (Ishak 5–6). Conclusions: Various pathomorphological abnormalities were found in more than half of patients with a median 11.74 years post-transplant follow-up. Most of them presented normal laboratory liver tests at the same time, suggesting a slow subclinical process leading to pathomorphological abnormalities. No single factor for the development of these abnormalities was found, but our study supports the need for protocol liver biopsies even in patients with normal/almost normal biochemical liver tests.

Disruption of epithelial junctional complex (EJC), especially tight junctions (TJ), resulting in increased intestinal permeability, is supposed to activate the enhanced immune response to gluten and to induce the development of celiac disease (CD). This study is aimed to present the role of EJC in CD pathogenesis. To analyze differentially expressed genes the next-generation mRNA sequencing data from CD326+ epithelial cells isolated from non-celiac and celiac patients were involved. Ultrastructural studies with morphometry of EJC were done in potential CD, newly recognized active CD, and non-celiac controls. The transcriptional analysis suggested disturbances of epithelium and the most significant gene ontology enriched terms in epithelial cells from CD patients related to the plasma membrane, extracellular exome, extracellular region, and extracellular space. Ultrastructural analyses showed significantly tighter TJ, anomalies in desmosomes, dilatations of intercellular space, and shorter microvilli in potential and active CD compared to controls. Enterocytes of fetal-like type and significantly wider adherence junctions were observed only in active CD. In conclusion, the results do not support the hypothesis that an increased passage of gluten peptides by unsealing TJ precedes CD development. However, increased intestinal permeability due to abnormality of epithelium might play a role in CD onset.