HPHS Journal Watch July and August 2024

American Journal of Clinical Pathology

5-Hydroxymethylcytosine (5-hmC) loss is a marker of malignancy in biliary neoplasms.

Gonzalez-Mancera MS, Siref A, Kosari K, et al. Am J Clin Pathol. 2024 Jul 5;162(1):41-50.

https://pubmed.ncbi.nlm.nih.gov/38345293

Adenocarcinomas of the biliary tract often present diagnostic challenges due to their histologic similarity to benign lesions. Mutations in IDH1/2, which are common in intrahepatic cholangiocarcinoma, can result in defective production of 5-hydroxymethylcytosine (5-hmC). Loss of 5-hmC staining may serve as a useful ancillary diagnostic tool for identifying biliary tract malignancies. The study demonstrated that 5-hmC loss occurred in 41 of 46 (89.1%) biliary malignancies. 5-hmC loss was more frequent in distal bile duct adenocarcinomas than in pancreatic ductal adenocarcinomas (88.2% versus 33.3%, respectively). The authors concluded that 5-hmC loss is a valuable diagnostic marker for distinguishing malignancies of the biliary tree from benign mimics.

Clinical Gastroenterology and Hepatology

Differential Effects of Genetic Polymorphism on Comorbid Disease in Metabolic Dysfunction–Associated Steatotic Liver Disease

Seko Y, Yamaguchi K, Shima T, et al. Clin Gastroenterol Hepatol . 2024 Jul;22(7):1436-1443.e4

https://pubmed.ncbi.nlm.nih.gov/38604296

This longitudinal multicenter cohort study investigated the impact of known genetic variants (PNPLA3 rs738409, TM6SF2 rs58542926, and HSD17B13 rs72613567) on hepatic fibrosis and liver-related events in metabolic dysfunction-associated steatotic liver disease (MASLD). The authors aim to analyze the risk of these genetic variants in Japanese populations based on the biopsies of 1178 Japanese patients with MASLD, who were followed for events such as hospitalization for any liver-related event (including HCC), gastroesophageal varices, ascites, and encephalopathy. Statistical analysis showed that PNPLA3 and TM6SF2 contributed to fibrosis progression and liver-related events, whereas HSD17B13 showed a protective effect against fibrosis progression. The authors conclude that genetic risk may be useful for assessing risk of liver-related events, particularly in patients without metabolic risk factors and in younger patients.

Cholangitis Induced by Immune Checkpoint Inhibitors: Analysis of Pharmacovigilance Data

Meunier L, Hountondji L, Jantzem H et al. Clin Gastroenterol Hepatol . 2024 Jul;22(7):1542-1545.e4

https://pubmed.ncbi.nlm.nih.gov/38110061

In this retrospective study, the authors investigated the natural course of cases of immune checkpoint inhibitor (ICI)-related cholangitis which were reported to the French pharmacovigilance system. ICI-cholangitis is an emerging immune-related adverse effect (irAE) that has been described to have a cholestatic profile with bile duct damage, longer time for resolution, and poorer response to immunosuppression. The authors summarize 48 cases of ICI-cholangitis in the French database. 40% of patients presented with another concurrent irAE, most commonly colitis. All patients had a mixed or cholestatic pattern and of the patients with a liver biopsy, 40% had bile duct involvement. Of these patients, 50% received steroids; 27% received ursodiol; and 1 patient received MMF; about a quarter improved without treatment and a quarter improved on ursodiol. Four patients eventually died. Cholangitis recurred in 3 of 6 patients who were rechallenged with ICI. The findings suggest a role for both therapeutic abstention and ursodiol as alternative to steroids in treatment of ICI-cholangitis.

Gastroenterology

Metabolic Dysfunction-Associated Fibrosis 5 (MAF-5) Score Predicts Liver Fibrosis Risk and Outcome in the General Population with Metabolic Dysfunction

van Kleef LA, Francque SM, Prieto-Ortiz JE, et al. Gastroenterology. 2024;167:357-367.

https://pubmed.ncbi.nlm.nih.gov/38513745

The authors developed a new anthropometrics-based score, the MAF-5 score, to identify individuals with metabolic dysfunction at risk of advanced liver disease. Validated in a cohort of 21,797 individuals, the MAF-5 score includes: (1) body mass index (BMI), (2) waist circumference and the BMI-waist circumference interaction, (3) diabetes status, (4) aspartate aminotransferase levels, and (5) platelet count. For the formula, refer to the paper. The score’s key advantage is its age-independent nature, ensuring consistent interpretation across different age groups. Patients are categorized into low-risk (score <0), intermediate-risk (score 0-1), and high-risk (score >1) for fibrosis. The MAF-5 score strongly correlates with fibrosis severity, whether measured by liver stiffness or histologically, and is associated with an increased risk of all-cause mortality, as demonstrated by multivariable Cox regression. Additionally, the MAF-5 score outperforms other non-invasive tests, such as the FIB-4 score. In summary, the MAF-5 score is an effective, age-independent tool for identifying high-risk individuals for fibrosis and mortality, using easily obtainable variables and incorporating the new nomenclature for steatotic liver disease.

Hepatology

Artificial intelligence scoring of liver biopsies in a phage II trial of semaglutide in nonalcoholic steatohepatitis.

Ratziu V, Francque S, Behling CA, et al. Hepatology2024;80:173-185.

https://pubmed.ncbi.nlm.nih.gov/38112484

Artificial intelligence (AI) and machine learning (ML) have been explored in several studies in patients with NASH. This is a post hoc analysis of a previously-published, randomized, double-blind, placebo-controlled trial that found clinical benefit with semaglutide in NASH, using central pathologist review of baseline and 72-week liver biopsies. ML was used to assess liver biopsies with scanned images (n=251) including a primary endpoint (NASH resolution without worsening of fibrosis), confirmatory secondary endpoint (improvement in liver fibrosis with no worsening of steatohepatitis), continuous fibrosis score (0-4) and categorical NASH CRN stage, grades of steatosis, lobular inflammation, and ballooning. ML and central pathologist review achieved similar results: both detected treatment benefit of semaglutide 0.4 mg vs placebo, with minor differences. Significantly, continuous scoring of fibrosis by ML found improvement with 0.4 mg semaglutide, whereas categorical scoring by pathologists did not, suggesting that ML may detect changes in fibrosis that are too subtle to be captured by assessment of categorical NAS stage. Interobserver agreement was better between the central pathologists than between ML and central pathologists; the ML tended to assign higher baseline stage and grades of steatosis, inflammation, and ballooning than pathologists, suggesting that ML has stricter criteria for assigning a value of “0” for histologic features in NASH. The authors conclude that ML has the potential to add value in the interpretation of histologic features of NASH in clinical trials.

Hepatology Communications

Whole-exome sequencing reveals novel cancer genes and actionable targets in biliary tract cancers in primary sclerosing cholangitis

Grimsruf MM, Forster M, Goeppert B, et al. Hepatol Commun . 2024 Jul 5;8(7):e0461.

https://pubmed.ncbi.nlm.nih.gov/38967597

In this cohort sequencing study, the authors performed whole-exome sequencing of paired and non-paired samples from 52 patients with PSC-associated biliary tract carcinomas (BTC). A number of genes previously identified as relevant in pancreatobiliary carcinomas were identified, including ARID2, ELF3, and PTPRD, and a subset of universal cancer genes were identified, including TP53, CDKN2A, SMAD4, KRAS, ERBB22, and BRAF. The study identified that actionable genes include FGFR3 and ERBB2 (amplified in 10%); possible targetable genes include MDM2 (amplification in 17%), KRAS (G12D), and BRAF (non-V600E types). None of the samples showed genomic alterations in IDH1, IDH2, BAP1, or FGFR2 (all of which are associated with small duct-type cholangiocarcinoma). The presence of alternations in RAS, TP53, and PI3K pathways were associated with reduced overall survival, but there was no difference in overall survival with high and low tumor mutational burden. The authors conclude that PSC-BTC are all large duct subtypes of cholangiocarcinoma with a number of possible targetable alterations.

High prevalence of short telomeres in idiopathic porto-sinusoidal vascular disorder

Coukos A, Saglietti C, Sempoux C, et al. Hepatol Commun . 2024 Jul 22;8(8):e0500.

https://pubmed.ncbi.nlm.nih.gov/39037376

In this monocentric cross-sectional sequencing study, the authors evaluate telomere length in patients with biopsy-proven idiopathic porto-sinusoidal vascular disorder (PSVD). Patients with short telomere syndrome (STS) have prematurely shortened telomeres and are known to manifest in the liver with PSVD. Peripheral blood leukocytes were investigated for telomere length via FISH and flow cytometry, and variants of telomere-related genes were identified via exome sequencing. In 22 patients with idiopathic PSVD, 73% had either short or very short telomeres (adjusted for age), and 64% had clinically significant portal hypertension. Shorter telomeres were also more frequent in males, patients with interstitial lung disease, chronic kidney disease, and portal hypertension. Variants in STS-related genes were identified in 4 patients, including DKC1, RTEL1, and TERT. The authors conclude that short and very short telomeres were prevalent in patients with idiopathic PSVD, suggesting that telomeres may play an important role in vascular liver disease.

Genetic variants associated with immune-mediated liver injury from checkpoint inhibitors

Fontana RJ, Li YJ, Chen V, et al. Hepatol Commun . 2024 Aug 26;8(9):e0518.

https://pubmed.ncbi.nlm.nih.gov/39185906

In this multi-institutional cohort study, the authors investigate the clinical features, histology, and genetic variants in patients with moderate to severe immune checkpoint inhibitor (ICI)-associated liver injury. The authors identified a total of 57 patients in a drug-induced liver injury network (DILIN) database. At the onset of liver injury, 53% had hepatocellular biochemistries; 35% had mixed biochemistries; and 15% had cholestatic biochemistries. Liver biopsies showed non-specific features, including portal and lobular hepatitis, cholestatic/biliary injury, diffuse glycogenosis, and zone 3 necrosis. Most patients presented within 6 months of exposure and were responsive to immunosuppressive therapy, but over a third of patients show recurrence of injury with ICI rechallenge.  Host immune response genes (including EDIL3 and SAMA5A) as well as genes involved in T-cell regulation were associated with CPI-liver injury. The authors conclude that there may be a role for T-cell regulation and adaptive immunity in the pathogenesis of ICI-associated liver injury.

Human Pathology

Steatohepatitic hepatocellular Carcinoma: A new approach to classifying morphological subtypes of hepatocellular carcinoma

Soon GST, Callea F, Burt AD, et al. Hum Pathol. 2024;149:55-65.

https://pubmed.ncbi.nlm.nih.gov/38876199

Histological subtyping of hepatocellular carcinoma (HCC) poses significant challenges due to intratumoral morphological heterogeneity. In an index cohort of 87 HCC cases, the authors observed that 45% exhibited notable intratumoral heterogeneity, with the highest incidence found in steatohepatitic HCC (SH-HCC) at 91%. The study aimed to determine if this heterogeneity followed consistent patterns and whether incorporating these patterns could enhance the histological classification of HCC, particularly for SH-HCC. They noted that SH-HCC typically begins as well-differentiated tumors characterized by substantial steatosis but evolves into forms showing a “burned-out” pattern (with reduced steatosis and increased ballooning) and/or a “scirrhous” pattern (marked by significant intratumoral fibrosis). Advanced morphological patterns observed included the macrotrabecular pattern, high-grade HCC with solid or trabecular growth, and the microsolid pattern. These findings suggest a need to revise the histological criteria for SH-HCC, advocating for a comprehensive evaluation of all observed patterns within a lesion rather than relying solely on specific cut-offs. The study proposed that lower-grade patterns may indicate early stages of morphological development and thus offer higher specificity for tumor subtyping. Additionally, CTNNB1 mutations may arise later in the progression of some SH-HCC cases, primarily in men. The study also emphasized that a lipid-rich or foamy histiocyte-like appearance should be regarded as part of the spectrum of SH-HCC morphological progression rather than as a separate subtype.

Journal of Hepatology

CRKL dictates anti-PD-1 resistance by mediating tumor-associated neutrophil infiltration in hepatocellular carcinoma.

Xie P, Yu M, Zhang B, et al. J Hepatol. 2024 Jul;81(1):93-107.

https://pubmed.ncbi.nlm.nih.gov/38403027

The effectiveness of immune checkpoint inhibitor (ICI) therapy for hepatocellular carcinoma (HCC) is limited by treatment resistance. This paper identifies the role of CT10 regulator of kinase-like (CRKL) in mediating resistance to anti-PD-1 therapy in hepatocellular carcinoma (HCC). CRKL overexpression negates the efficacy of anti-PD-1 treatment by mobilizing tumor-associated neutrophils (TANs), which inhibit the infiltration and function of CD8+ T cells. The authors confirmed positive correlations between CRKL, β-catenin, VEGFα, and CXCL1 in human HCC samples and found that activation of the CRKL/β-catenin/VEGFα/CXCL1 axis is a major barrier to successful anti-PD-1 therapy. Specifically, elevated CRKL levels are associated with poor prognosis in HCC patients and reduced CD8+ T-cell infiltration. CRKL overexpression reshapes the immune landscape by recruiting TANs, with VEGFα and CXCL1 being essential for CRKL-driven TAN infiltration in the tumor microenvironment. This study suggests that combining CRKL inhibitors with anti-PD-1 therapy may improve HCC treatment outcomes and shed a light that these molecules could potentially serve as biomarkers to predict the response to anti-PD-1 therapy in HCC.

Prepared by:

Dana Balitzer, MD (Editor); University of California San Francisco

Clifton Fulmer, MD, PhD; Cleveland Clinic

Nigar Anjuman Khurram, MD; University of Pittsburgh

Yuanxin Liang, MD, PhD; Yale School of Medicine

Joseph Misdraji, MD; Yale School of Medicine

Juan Putra, MD; Boston Children’s Hospital

Daniel Roberts MD; Cleveland Clinic

Angela R. Shih, MD; Massachusetts General Hospital

Xuefeng Zhang, MD; Cleveland Clinic