The new definition of dominant stricture in primary sclerosing cholangitis: Prevalence and clinical significance.

BACKGROUND AND AIMS: A new definition of dominant stricture (NDS) has recently been defined for patients with primary sclerosing cholangitis (PSC). Prevalence and clinical features of this, compared to traditional dominant stricture (TDS), have not been reported. METHODS: In this single-centre longitudinal prospective cohort study, all PSC patients who underwent endoscopic retrograde cholangiopancreatography (ERCP) between October 2021 and 2022 were recruited. Symptoms of cholestasis, laboratory values (P-alkaline phosphatase, P-Bilirubin), Helsinki PSC-score, brush cytology findings and need for endoscopic therapy (i.e. dilation, stenting) were prospectively collected. RESULTS: Overall, 228 patients with PSC underwent 248 ERCPs. NDS was detected in 43 (17%; 36 patients) and TDS without NDS (TDS group) was detected in 62 (25%; 58 patients) ERCPs, respectively; in the remaining 143 ERCPs, neither TDS nor NDS was seen (no dominant stricture [NoDS] group). PSC duration (median 8 years) and patient's age did not differ between the three groups; males presented more often with NDS. Patients with NDS were more often symptomatic, had higher cholestatic liver enzymes, advanced bile duct disease and markers of biliary inflammation (p < .001). Patients with NDS needed dilation (81%) and stenting (21%) more often than the TDS group (60% and 5%, respectively). Dysplasia in brush cytology was more common in TDS (5%) and NDS (9%) than in NoDS (3%) groups (p = .04), but did not differ between TDS and NDS groups. CONCLUSIONS: Dominant stricture according to the new definition developed in 17% of PSC patients in our cohort and identifies patients with more advanced disease, biliary inflammation and need of endo-therapy.

Absence of orthopaedia homeobox protein (OTP) expression is associated with disease spread and adverse outcome in pulmonary carcinoid tumour patients.

Pulmonary carcinoid (PC) tumours typically have a good prognosis, although metastases occur, and the disease may progress after a long period of time. Expression of orthopaedia homeobox protein (OTP) has been recognized as a possible independent prognostic marker in PCs. Immunohistochemical (IHC) OTP expression has been associated with better prognosis, but the staining has yet to be implemented in routine clinical diagnostics. In response to this, two new monoclonal OTP antibodies were recently developed.This retrospective study included 164 PC patients operated on at Helsinki University Hospital between 1990 and 2020. Tissue microarray slides, prepared from formalin-fixed and paraffin-embedded primary tumour samples, were stained with OTP IHC using one polyclonal and two novel monoclonal antibodies.Absence of OTP expression was associated with a shorter disease-specific survival (DSS) and disease progression (p < 0.001). Patients without OTP expression had a 5-year DSS of 73-79%, whereas 5-year DSS was 91-94% with OTP expression, depending on the primary antibody. In a univariable Cox regression model, absence of OTP expression was associated with adverse outcome along with atypical histological subtype, metastatic disease, Ki-67 proliferation index > 1%, and larger tumour size. In a multivariable Cox regression model, only absence of OTP expression and lymph node involvement at the time of diagnosis were associated with risk of worse prognosis. All three antibodies showed good concordance with each other.Our findings support the role of OTP as an independent prognostic marker in PCs and applicability of IHC staining in routine clinical use with novel monoclonal antibodies.

Coexistence of metabolic-associated fatty liver disease and autoimmune or toxic liver disease.

Fatty liver disease (FLD) affects approximately 25% of global adult population. Metabolic-associated fatty liver disease (MAFLD) is a term used to emphasize components of metabolic syndrome in FLD. MAFLD does not exclude coexistence of other liver disease, but impact of coexisting MAFLD is unclear. We investigated prevalence and characteristics of MAFLD in patients with biopsy-proven autoimmune hepatitis (AIH), primary biliary cholangitis (PBC), primary sclerosing cholangitis (PSC), or toxic liver disease. Liver histopathology and clinical data from Helsinki University Hospital district (1.7 million inhabitants) between 2009 and 2019 were collected from patients with AIH, PBC, PSC, or toxic liver disease at the time of diagnosis. MAFLD was diagnosed as macrovesicular steatosis ≥5% together with obesity, type-2 diabetes, or signs of metabolic dysregulation. Of 648 patients included, steatosis was observed in 15.6% (n = 101), of which 94.1% (n = 95) was due to MAFLD. Prevalence of coexisting MAFLD in the four liver diseases varied between 12.4 and 18.2% (P = 0.483). Fibrosis was more severe in MAFLD among patients with toxic liver disease (P = 0.01). Histopathological characteristics otherwise showed similar distribution among MAFLD and non-FLD controls. Alcohol consumption was higher in MAFLD group among patients with AIH or PBC (P < 0.05 for both). In AIH, smoking was more common in patients with coexisting MAFLD (P = 0.034). Prevalence of coexisting MAFLD in other primary liver diseases is lower than reported in general population. Histopathology of MAFLD patients did not clearly differ from non-FLD ones. Alcohol and smoking were associated with MAFLD in AIH.

High immune cell infiltration predicts improved survival in cholangiocarcinoma.

Background: Antitumoral immune response has a crucial role in constraining cancer. However, previous studies on cholangiocarcinoma (CCA), a rare and aggressive cancer, have reported contradictory findings on the prognostic impact of tumor-infiltrating T-lymphocytes. We aimed to clarify the effect of tumor-infiltrating CD3+ and CD8+ lymphocytes and PD-1/PD-L1 expression on CCA prognosis. Methods: CD3+, CD8+, and PD-1+ lymphocyte densities, as well as PD-L1 expression rate were analyzed from stained tissue microarray samples from the tumor center and invasive margin of 47 cholangiocarcinomas. The association of CD3+ and CD8+ based Immune cell score (ICS) and its components with overall survival was evaluated, adjusting for age, sex, TNM stage, radicality of surgery, tumor location, and PD-L1 expression on immune cells. Results: Low ICS was a strong independent prognostic factor for worse overall survival (Hazard ratio 9.27, 95% confidence interval 2.72-31.64, P<0.001). Among the ICS components, high CD8+ lymphocyte infiltration at the tumor center had the most evident impact on patient outcome. PD-1 and PD-L1 expression on immune cells did not have a significant impact on overall survival alone; however, PD-L1 positivity seemed to impair survival for ICSlow subgroup. Conclusion: Identifying patient subgroups that could benefit from immunotherapy with PD-1/PD-L1 pathway blockade may help improve treatment strategies for this aggressive cancer. Our findings highlight the importance of evaluating the immune contexture in cholangiocarcinoma, as ICS serves as a strong independent prognostic and selective factor for patients who might benefit from immunotherapy.

External validation of a deep learning-based algorithm for detection of tall cells in papillary thyroid carcinoma: A multicenter study.

The tall cell subtype (TC-PTC) is an aggressive subtype of papillary thyroid carcinoma (PTC). The TC-PTC is defined as a PTC comprising at least 30% epithelial cells that are three times as tall as they are wide. In practice, this definition is difficult to adhere to, resulting in high inter-observer variability. In this multicenter study, we validated a previously trained deep learning (DL)-based algorithm for detection of tall cells on 160 externally collected hematoxylin and eosin (HE)-stained PTC whole-slide images. In a test set of 360 manual annotations of regions of interest from 18 separate tissue sections in the external dataset, the DL-based algorithm detected TCs with a sensitivity of 90.6% and a specificity of 88.5%. The DL algorithm detected non-TC areas with a sensitivity of 81.6% and a specificity of 92.9%. In the validation datasets, 20% and 30% TC thresholds correlated with a significantly shorter relapse-free survival. In conclusion, the DL algorithm detected TCs in unseen, external scanned HE tissue slides with high sensitivity and specificity without any retraining.

Protocol liver biopsy predicts graft survival after liver transplantation.

BACKGROUND: The use of protocol liver biopsy to monitor liver allograft status remains controversial. There is limited data from modern transplantation populations that includes protocol biopsies to evaluate its value in predicting clinical outcomes. METHODS: All protocol liver biopsies were identified from 875 patients who underwent liver transplantation at Helsinki University Hospital between 2000 and 2019. Each histologic component was analyzed for its ability to predict long-term outcomes, especially graft survival. We determined the frequency of significant biopsy findings based on the Banff working group definition. Liver function tests (LFTs) and clinical markers were evaluated for their ability to predict significant biopsy findings. RESULTS: In total, 867 protocol liver biopsies were analyzed. Significant findings were identified in 20.1% of the biopsies. In the first protocol biopsy, steatohepatitis (hazard ratio [HR] 3.504, p = .03) and moderate or severe congestion (HR 3.338, p = .04) predicted graft loss. The presence of cholangitis (HR 2.563, p = .04), necrosis (HR 7.635, p < .001), mild congestion (HR 4.291, p = .009), and significant biopsy finding (HR 2.540, p = .02) predicted inferior death-censored graft survival. While the degree of elevation of LFTs was positively associated with significant biopsy findings, the discrimination was poor (AUC .572-.622). Combined LFTs and clinical risk factors remained suboptimal for discriminating significant biopsy findings (AUC .696). CONCLUSIONS: Our findings support the use of protocol liver biopsies after liver transplantation since they frequently revealed changes associated with long-term outcomes, even when LFTs were normal.

NGS of brush cytology samples improves the detection of high-grade dysplasia and cholangiocarcinoma in patients with primary sclerosing cholangitis: A retrospective and prospective study.

BACKGROUND: Biliary dysplasia, a precursor of cholangiocarcinoma (CCA), is a common complication of primary sclerosing cholangitis. Patients with high-grade dysplasia (HGD) or early CCA who have received oncological treatment are candidates for liver transplantation. The preoperative diagnosis of CCA or HGD is challenging, and the sensitivity of biliary brush cytology (BC) is limited. METHODS: By using next-generation sequencing (NGS), we retrospectively analyzed archived tissue samples (n=62) obtained from explanted liver tissue and CCA samples to identify oncogenic mutations that occur during primary sclerosing cholangitis carcinogenesis. BC samples were prospectively collected from patients with primary sclerosing cholangitis (n=97) referred for endoscopic retrograde cholangiography to measure the diagnostic utility of NGS combined with BC compared with traditional cytology alone. RESULTS: Mutations in KRAS, GNAS, FLT3, RNF43, TP53, ATRX, and SMAD4 were detected in archived CCA or HGD samples. KRAS, GNAS, TP53, CDKN2A, FBXW7, BRAF, and ATM mutations were detected in prospectively collected brush samples from patients with histologically verified CCA or HGD. One patient with low-grade dysplasia in the explanted liver had KRAS and GNAS mutations in brush sample. No mutations were observed in brush samples or archived tissues in liver transplantation cases without biliary neoplasia. While KRAS mutations are common in biliary neoplasms, they were also observed in patients without biliary neoplasia during surveillance. CONCLUSIONS: In summary, NGS of BC samples increased the sensitivity of detecting biliary neoplasia compared with traditional cytology. Performing NGS on BC samples may help diagnose HGD or early CCA, benefiting the timing of liver transplantation.

Marked difference in liver fat measured by histology vs. magnetic resonance-proton density fat fraction: A meta-analysis.

Background & Aims: Pathologists quantify liver steatosis as the fraction of lipid droplet-containing hepatocytes out of all hepatocytes, whereas the magnetic resonance-determined proton density fat fraction (PDFF) reflects the tissue triacylglycerol concentration. We investigated the linearity, agreement, and correspondence thresholds between histological steatosis and PDFF across the full clinical spectrum of liver fat content associated with non-alcoholic fatty liver disease. Methods: Using individual patient-level measurements, we conducted a systematic review and meta-analysis of studies comparing histological steatosis with PDFF determined by magnetic resonance spectroscopy or imaging in adults with suspected non-alcoholic fatty liver disease. Linearity was assessed by meta-analysis of correlation coefficients and by linear mixed modelling of pooled data, agreement by Bland-Altman analysis, and thresholds by receiver operating characteristic analysis. To explain observed differences between the methods, we used RNA-seq to determine the fraction of hepatocytes in human liver biopsies. Results: Eligible studies numbered 9 (N = 597). The relationship between PDFF and histology was predominantly linear (r = 0.85 [95% CI, 0.80-0.89]), and their values approximately coincided at 5% steatosis. Above 5% and towards higher levels of steatosis, absolute values of the methods diverged markedly, with histology exceeding PDFF by up to 3.4-fold. On average, 100% histological steatosis corresponded to a PDFF of 33.0% (29.5-36.7%). Targeting at a specificity of 90%, optimal PDFF thresholds to predict histological steatosis grades were ≥5.75% for ≥S1, ≥15.50% for ≥S2, and ≥21.35% for S3. Hepatocytes comprised 58 ± 5% of liver cells, which may partly explain the lower values of PDFF vs. histology. Conclusions: Histological steatosis and PDFF have non-perfect linearity and fundamentally different scales of measurement. Liver fat values obtained using these methods may be rendered comparable by conversion equations or threshold values. Impact and implications: Magnetic resonance-proton density fat fraction (PDFF) is increasingly being used to measure liver fat in place of the invasive liver biopsy. Understanding the relationship between PDFF and histological steatosis fraction is important for preventing misjudgement of clinical status or treatment effects in patient care. Our analysis revealed that histological steatosis fraction is often significantly higher than PDFF, and their association varies across the spectrum of fatty liver severity. These findings are particularly important for physicians and clinical researchers, who may use these data to interpret PDFF measurements in the context of histologically evaluated liver fat content.