Sterling, Richard K

Background and Aims: Transient elastography (TE), shear wave elastography, and/or magnetic resonance elastography (MRE), each providing liver stiffness measurement (LSM), are the most studied imaging-based noninvasive liver disease assessment (NILDA) techniques. To support the American Association for the Study of Liver Diseases guidelines on NILDA, we summarized the evidence on the accuracy of these LSM methods to stage liver fibrosis (F). Approach and Results: A comprehensive search for studies assessing LSM by TE, shear wave elastography, or MRE for the identification of significant fibrosis (F2-4), advanced fibrosis (F3-4), or cirrhosis (F4), using histopathology as the standard of reference by liver disease etiology in adults or children from inception to April 2022 was performed. We excluded studies with <50 patients with a single disease entity and mixed liver disease etiologies (with the exception of HCV/HIV coinfection). Out of 9447 studies, 240 with 61,193 patients were included in this systematic review. In adults, sensitivities for the identification of F2-4 ranged from 51% to 95%, for F3-4 from 70% to 100%, and for F4 from 60% to 100% across all techniques/diseases, whereas specificities ranged from 36% to 100%, 74% to 100%, and 67% to 99%, respectively. The largest body of evidence available was for TE; MRE appeared to be the most accurate method. Imaging-based NILDA outperformed blood-based NILDA in most comparisons, particularly for the identification of F3-4/F4. In the pediatric population, imaging-based NILDA is likely as accurate as in adults. Conclusions: LSM from TE, shear wave elastography, and MRE shows acceptable to outstanding accuracy for the detection of liver fibrosis across various liver disease etiologies. Accuracy increased from F2-4 to F3-4 and was the highest for F4. Further research is needed to better standardize the use of imaging-based NILDA, particularly in pediatric liver diseases.

Background and Aims: Blood-based biomarkers have been proposed as an alternative to liver biopsy for noninvasive liver disease assessment in chronic liver disease. Our aims for this systematic review were to evaluate the diagnostic utility of selected blood-based tests either alone, or in combination, for identifying significant fibrosis (F2-4), advanced fibrosis (F3-4), and cirrhosis (F4), as compared to biopsy in chronic liver disease. Approach and Results: We included a comprehensive search of databases including Ovid MEDLINE(R), EMBASE, Cochrane Database, and Scopus through to April 2022. Two independent reviewers selected 286 studies with 103,162 patients. The most frequently identified studies included the simple aspartate aminotransferase-to-platelet ratio index and fibrosis (FIB)-4 markers (with low-to-moderate risk of bias) in HBV and HCV, HIV-HCV/HBV coinfection, and NAFLD. Positive (LR+) and negative (LR−) likelihood ratios across direct and indirect biomarker tests for HCV and HBV for F2-4, F3-4, or F4 were 1.66–6.25 and 0.23–0.80, 1.89–5.24 and 0.12–0.64, and 1.32–7.15 and 0.15–0.86, respectively; LR+ and LR− for NAFLD F2-4, F3-4, and F4 were 2.65–3.37 and 0.37–0.39, 2.25–6.76 and 0.07–0.87, and 3.90 and 0.15, respectively. Overall, the proportional odds ratio indicated FIB-4 <1.45 was better than aspartate aminotransferase-to-platelet ratio index <0.5 for F2-4. FIB-4 >3.25 was also better than aspartate aminotransferase-to-platelet ratio index >1.5 for F3-4 and F4. There was limited data for combined tests. Conclusions: Blood-based biomarkers are associated with small-to-moderate change in pretest probability for diagnosing F2-4, F3-4, and F4 in viral hepatitis, HIV-HCV coinfection, and NAFLD, with limited comparative or combination studies for other chronic liver diseases.

Background and Aims: Portal hypertension is a serious complication of cirrhosis, which leads to life-threatening complications. HVPG, a surrogate of portal pressure, is the reference standard test to assess the severity of portal hypertension. However, since HVPG is limited by its invasiveness and availability, noninvasive liver disease assessments to assess portal pressure, especially clinically significant portal hypertension (CSPH), are needed. Approach and Results: We conducted a systematic review of Ovid MEDLINE(R) Ovid EMBASE, Ovid Cochrane Central Register of Controlled Trials, Ovid Cochrane Database of Systematic Reviews, and Scopus from each database’s inception to April 22, 2022. We included only studies in English that examined ≥50 patients in single liver disease etiologies, which compared noninvasive tests (blood and/or imaging) to HVPG for predicting clinically significant portal hypertension (CSPH; defined as HVPG ≥ 10 mm Hg) in patients with chronic liver disease. Outcomes included measures of diagnostic test accuracy. Additionally, a narrative review of studies not eligible for the systematic review is also provided. Nine studies with 2492 patients met the inclusion criteria. There was substantial heterogeneity with regard to liver disease studied and cutoff values used to detect CSPH. Blood-based tests, including aspartate-to-platelet ratio index (APRI) (56% sensitivity and 68% specificity) and FIB-4 (54% sensitivity and 73% specificity) had low accuracy measures. Imaging-based tests (transient elastography and shear wave elastography detection of liver stiffness measurement [LSM]) had better accuracy but also had substantial variation; at 15 kPa, TE sensitivity was 90%–96% and specificity was 48%–50%, while at 25 kPa, its sensitivity and specificity were 57%–85% and 82%–93%, respectively. The narrative review suggested that imaging-based tests are the best available noninvasive liver disease assessment to detect CSPH; CSPH is highly unlikely to be present at an LSM ≤15 kPa and likely to be present at an LSM ≥25 kPa. Conclusions: While imaging-based noninvasive liver disease assessment appeared to have higher accuracy than blood-based tests to detect CSPH, only 9 studies fit the a priori established inclusion criteria for the systematic review. In addition, there was substantial study heterogeneity and variation in cutoffs for LSM to detect CSPH, limiting the ability to establish definitive cutoffs to detect CSPH.