Second harmonic generation microscopy provides accurate automated staging of liver fibrosis in patients with non-alcoholic fatty liver disease

Abstract

BackgroundAssessment of severity of liver fibrosis is essential in the management of non-alcoholic fatty liver disease (NAFLD). Second Harmonic Generation (SHG) microscopy is a novel optical tissue imaging system that provides automated quantification of fibrosis based on unique architectural features of collagen. This study aims to develop and validate a SHG-based index for automated staging of liver fibrosis in patients with NAFLD.MethodsSHG microscopy was performed on archived liver biopsy specimens from 83 patients with NAFLD. A unique algorithm was developed to identify specific SHG parameters that correlated with fibrosis stage. The accuracy of the algorithm was compared against clinical assessment by experienced liver histopathologists using the Brunt fibrosis staging and further validated using the leave-one-out cross-validation method.ResultsMean age of the study cohort was 51.8 ± 11.7 years, with 41% males. A fibrosis index (SHG B-index) was developed comprising 14 unique SHG-based collagen parameters that correlated with severity of NAFLD fibrosis in a continuous fashion. The SHG B-index had excellent correlation with Brunt fibrosis stage (Spearman’s correlation 0.820, p<0.001). AUROCs for prediction of Brunt fibrosis stages 1, 2, 3 and 4 were 0.853, 0.967, 0.985 and 0.941 respectively. In the cross-validation analysis, the SHG B-index demonstrated high specificity for diagnosis of all grades of fibrosis. A SHG B-index score of >1.76 had an overall diagnostic accuracy of 98.5% for prediction of presence of bridging fibrosis (Brunt stage ≥3) with sensitivity of 87.5%, specificity 98.0%, positive predictive value 96.6% and negative predictive value 92.6%.ConclusionThe SHG B-index is a unique SHG-based index that provides accurate automated assessment of fibrosis stage in NAFLD patients.

qFIBS: An Automated Technique for Quantitative Evaluation of Fibrosis, Inflammation, Ballooning, and Steatosis in Patients With Nonalcoholic Steatohepatitis

“…Automatic quantification of lobular inflammation and ballooning on digital images of H&E‐stained slides has also been reported: R values were 0.45 for lobular inflammation and 0.46 for ballooning, AUC values were 0.95 for lobular inflammation and 0.98 for ballooning . Others have demonstrated that LF could be quantified using a range of techniques, such as collagen proportionate area and dual‐photon microscopy, but these studies have tended to be in mixed etiology cohorts, or derived from single centers, and histological characteristics other than fibrosis were not assessed. In contrast, the current study derives NAFLD/NASH cases associated samples from a large international, multicenter collaboration and therefore provides an opportunity to not only comprehensively assess key histological features of NASH, but also to demonstrate utility across differing ethnicities, environmental/nutritional backgrounds, and age groups (adult and pediatric disease).…”

“…Wang et al first established an SHG‐based quantification of fibrosis‐related parameters (Q‐FP) model in NAFLD that offered a more refined assessment of collagen architectural changes along a continuous, quantitative scale. Liu et al and Chang et al subsequently described the use of SHG to autoquantify collagen deposition and assess fibrosis in pediatric and adult patients with NAFLD. To further explore the utility and potential of SHG in the context of NAFLD, we carried out an international, multicenter study to develop and validate a SHG‐based automated quantitative evaluation tool, qFIBS, for the evaluation of fibrosis as well as lobular inflammation, ballooning, and steatosis, with the goal of increasing the precision of disease severity assessment following the confirmation of an NAFLD/NASH diagnosis by expert hepatopathologist consensus .…”

“…Liu et al and Chang et al subsequently described the use of SHG to autoquantify collagen deposition and assess fibrosis in pediatric and adult patients with NAFLD. To further explore the utility and potential of SHG in the context of NAFLD, we carried out an international, multicenter study to develop and validate a SHG‐based automated quantitative evaluation tool, qFIBS, for the evaluation of fibrosis as well as lobular inflammation, ballooning, and steatosis, with the goal of increasing the precision of disease severity assessment following the confirmation of an NAFLD/NASH diagnosis by expert hepatopathologist consensus . This present study comprises a large, multicenter cohort that includes patients from different ethnicities, age ranges (pediatric to adult), and varying severity of NAFLD, from simple steatosis to cirrhosis.…”

High-Throughput, Machine Learning–Based Quantification of Steatosis, Inflammation, Ballooning, and Fibrosis in Biopsies From Patients With Nonalcoholic Fatty Liver Disease

“…11 Furthermore, to our knowledge, very few studies have attempted a quantitative assessment of ballooning and inflammation in NAFLD. 12,13 A recent consensus document from the Case Definitions Working Group of the Liver Forum recognized the potential role of quantitation as an entry criterion to drug trials within the field. 14 This study's primary aim was to develop and validate a high-throughput, fully automated, machine learning-based system for the quantitation of all 4 key histologic features contributing to the NASH CRN score, using liver biopsy specimens obtained from patients with NAFLD.…”

“…Note: To access the supplementary material accompanying this article, visit the online version of Clinical Gastroenterology and Hepatology at www.cghjournal.org, and at https://doi.org/10.1016/j.cgh.2019. 12…”