Little is known on the mechanism of liver injury mediated by bile acids following Kasai portoenterostomy (KPE) in biliary atresia (BA). We sought to quantify individual serum bile acids, 7-alpha-hydroxy-4-cholesten-3-one (C4), and fibroblast growth factor 19 (FGF19) after KPE and to evaluate their prognostic utility and transcriptomic regulation. Serum (n=244) and liver specimens (n=105) prospectively obtained from BA patients (n=54) after KPE were included. Bile acids were analyzed using mass spectrometry, gene expression with quantitative PCR, and histopathology using a neural network model. Following KPE, serum bile acids correlated positively with biochemical liver injury, pediatric end-stage liver disease score, liver stiffness, histological ductular reaction, and liver fibrosis. Bile acids were higher among patients who developed portal hypertension (79.6 vs. 11.9 μmol/l, p<0.0001), esophageal varices (91.6 vs. 16.2 μmol/l, p<0.0001), or required liver transplantation (LT, 115.3 vs. 22.0 μmol/l, p<0.0001) during follow up; bile acids predicted these outcomes in time-dependent regression models. Accumulation of conjugated bile acids, cholic acid, and taurine conjugates predicted LT risk while associating with histological liver injury. Serum C4 (0.04 vs. 0.00 μmol/l, p=0.04) and liver CYP7A1 were higher in native liver survivors than in LT patients (fold-change 16.9 vs. 7.0, p=0.02). Primary bile acids correlated negatively with C4 (R=-0.38, p<0.001) and CYP7A1 (R=-0.49, p=0.01). Unlike in native liver survivors (R=-0.19, p=0.66), serum FGF19 correlated with liver FGF19 (R=0.59, p=0.04) without an inverse association with serum primary bile acids in LT patients (R=0.26, p=0.08). Accumulation and altered composition of serum bile acids predicted progressive liver disease and poorer transplant-free survival following KPE. Poor prognosis was associated with low bile acid synthesis and aberrantly increased liver FGF19. Biliary atresia (BA), a fibro-obliterating biliary disease of infants, remains the most common indication for pediatric liver transplantation caused by rapid progression of liver injury. To identify predictive biomarkers of disease progression and to elucidate the pathophysiology of BA liver injury, we profiled serum bile acids and studied their liver metabolism after Kasai portoenterostomy. Accumulation and altered composition of circulating bile acids predicted progression of liver disease and need for liver transplantation. Patients with poor prognosis showed low bile acid synthesis and abnormal liver expression of fibroblast growth factor 19.

Background: We aimed to quantify ductular reaction (DR) in biliary atresia using a neural network in relation to underlying pathophysiology and prognosis. Methods: Image-processing neural network model was applied to 259 cytokeratin-7–stained native liver biopsies of patients with biliary atresia and 43 controls. The model quantified total proportional DR (DR%) composed of portal biliary epithelium (BE%) and parenchymal intermediate hepatocytes (PIH%). The results were related to clinical data, Sirius Red–quantified liver fibrosis, serum biomarkers, and bile acids. Results: In total, 2 biliary atresia biopsies were obtained preoperatively, 116 at Kasai portoenterostomy (KPE) and 141 during post-KPE follow-up. DR% (8.3% vs. 5.9%, p=0.045) and PIH% (1.3% vs. 0.6%, p=0.004) were increased at KPE in patients remaining cholestatic postoperatively. After KPE, patients with subsequent liver transplantation or death showed an increase in DR% (7.9%–9.9%, p = 0.04) and PIH% (1.6%–2.4%, p = 0.009), whereas patients with native liver survival (NLS) showed decreasing BE% (5.5%–3.0%, p = 0.03) and persistently low PIH% (0.9% vs. 1.3%, p = 0.11). In Cox regression, high DR predicted inferior NLS both at KPE [DR% (HR = 1.05, p = 0.01), BE% (HR = 1.05, p = 0.03), and PIH% (HR = 1.13, p = 0.005)] and during follow-up [DR% (HR = 1.08, p<0.0001), BE% (HR = 1.58, p = 0.001), and PIH% (HR = 1.04, p = 0.008)]. DR% correlated with Sirius red–quantified liver fibrosis at KPE (R = 0.47, p<0.0001) and follow-up (R = 0.27, p = 0.004). A close association between DR% and serum bile acids was observed at follow-up (R = 0.61, p<0.001). Liver fibrosis was not prognostic for NLS at KPE (HR = 1.00, p = 0.96) or follow-up (HR = 1.01, p = 0.29). Conclusions: DR predicted NLS in different disease stages before transplantation while associating with serum bile acids after KPE.

Familial cardiomyopathy in pediatric stages is a poorly understood presentation of heart disease in children that is attributed to pathogenic mutations. Through exome sequencing, we report a homozygous variant in tropomodulin 1 (TMOD1; c.565C>T, p.R189W) in three individuals from two unrelated families with childhood-onset dilated and restrictive cardiomyopathy. To decipher the mechanism of pathogenicity of the R189W mutation in TMOD1, we utilized a wide array of methods, including protein analyses, biochemistry and cultured cardiomyocytes. Structural modeling revealed potential defects in the local folding of TMOD1^R189W and its affinity for actin. Cardiomyocytes expressing GFP-TMOD1^R189W demonstrated longer thin filaments than GFP-TMOD1^wt-expressing cells, resulting in compromised filament length regulation. Furthermore, TMOD1^R189W showed weakened activity in capping actin filament pointed ends, providing direct evidence for the variant’s effect on actin filament length regulation. Our data indicate that the p.R189W variant in TMOD1 has altered biochemical properties and reveals a unique mechanism for childhood-onset cardiomyopathy.

Evaluating invasion in non-mucinous adenocarcinoma (NMA) of the lung is crucial for accurate pT-staging. This study compares the World Health Organization (WHO) with a recently modified NMA classification. A retrospective case-control study was conducted on small NMA pT1N0M0 cases with a 5-year follow-up. Seventy cases were reviewed by 42 pulmonary pathologists first according to the WHO classification and after tutorial according to a modified classification. A third round was conducted based on feedback from 41 peers of previous rounds. Additionally, orthogonal biomarker analysis was performed. In the first two rounds, 42 pathologists from 13 countries assessed all 70 cases, while 36 pathologists evaluated 41 non-unanimous cases in the third round. Kappa values for invasiveness increased in rounds 1, 2, and 3 to 0.27, 0.45 and 0.62, respectively. In contrast to low variation in total tumor size measurements (6 %), a marked increase in invasive tumor size variation was observed (42 %), which was associated with high uncertainty. In the third round 10 cases were non-invasive, all without recurrence. The modified classification showed in the 3rd round marked reduction of the variation in pT staging compared to the current WHO classification. Proliferation rate, tumor mutational burden, and transcriptomic profiles supported the distinction between invasive cases and non-invasive cases of the modified classification. The modified classification demonstrates essentially higher reproducibility compared to the current WHO classification in NMA. The modified classification proves valuable in identifying low-risk lesions that are entirely non-invasive, and is supported by biomarker analysis.

While KRAS is the most frequently mutated oncogene in non-small cell lung cancer (NSCLC), KRAS-mutant tumors have long been considered difficult to treat and thus, an unmet need still remains. Partly due to the lack of targeted treatments, comprehensive real-world description of NSCLC patients with KRAS mutation is still largely missing in Finland. In this study, all adult patients diagnosed with locally advanced and unresectable or metastatic NSCLC from 1 January 2018 to 31 August 2020 at the Hospital District of Helsinki and Uusimaa were first identified in this retrospective registry-based real-world study. The final cohort included only patients tested with next generation sequencing (NGS) and was stratified by the KRAS mutation status. A total of 383 patients with locally advanced and unresectable or metastatic NSCLC and with NGS testing performed were identified. Patients with KRAS mutation (KRAS G12C n = 35, other KRAS n = 74) were younger than patients without KRAS mutations, were all previous or current smokers, and had more often metastatic disease at diagnosis. Also, these patients had poorer survival, with higher age, Charlson comorbidity index (CCI) being 5 or above, and KRAS G12C being the most significant risk factors associated with poorer survival. This suggests that the patients with KRAS mutation have a more aggressive disease and/or tumors with KRAS mutation are more difficult to treat, at least without effective targeted therapies.

Objectives: To investigate the prognostic significance of aspartate aminotransferase to platelet ratio index (APRI) in relation to histopathological features across the clinical course of biliary atresia (BA). Methods: In this observational cohort study, we enrolled 135 BA patients with available APRI values at Kasai portoenterostomy (KPE, n = 116) or at post‐KPE follow‐up ( n = 70; serum samples, n = 139; liver biopsies, n = 139). APRI was matched to manual scorings of liver histology, ductular reaction (DR) analysed using neural network model and fibrosis quantified from Sirius Red‐stained sections. Results: APRI was elevated at both KPE and post‐KPE follow‐up (0.92 vs. 1.2, p = 0.5), and associated with biochemical markers of cholestasis, and decreased liver function. At KPE, APRI was higher in patients failing to resolve cholestasis postoperatively (0.80 vs. 0.96, p = 0.02) and both at KPE (0.77 vs. 0.94, p = 0.06) and post‐KPE (0.7 vs. 2.1, p < 0.001) in those with subsequent need for liver transplant (LT). Across the disease course, APRI moderately predicted LT need (at KPE, HR = 1.4, p = 0.01; post‐KPE, HR = 1.2, p < 0.001). APRI correlated with DR (at KPE, R = 0.37, p < 0.001; post‐KPE, R = 0.35, p < 0.001), composed of biliary epithelium ( R = 0.34, p < 0.001; R = 0.25, p < 0.01) and parenchymal intermediate hepatocytes ( R = 0.33, p < 0.001; R = 0.43, p < 0.001) during the entire clinical course. APRI showed no correlation with quantified liver fibrosis at KPE ( R = 0.16, p = 0.13), but correlated with quantified fibrosis ( R = 0.22, p = 0.02) and Metavir staging ( R = 0.46, p < 0.001) after KPE. No association was observed with portal inflammatory cell infiltration or histological cholestasis. Conclusions: APRI reflects biliary and portal injury rather than generalised liver fibrosis and associates with poor prognosis in BA.