Background: Serum mac-2-binding protein glycosylation isomer (M2BPGi) is a new biomarker for liver fibrosis. However, its performance in metabolic dysfunction-associated steatotic liver disease (MASLD), particularly in obese patients, remains to be explored. Methods: This study evaluated the role of M2BPGi in predicting liver fibrosis in 205 patients with MASLD using magnetic resonance elastography (MRE) as a reference. The performance of M2BPGi was compared to vibration-controlled transient elastography (VCTE), FIB-4, APRI, and NFS. The PNPLA3, TM6SF2, and HSD17B13 polymorphisms were assessed by allelic discrimination assays. Results: The area under the ROC curves for VCTE, M2BPGi FIB-4, APRI, and NFS in differentiating significant fibrosis were 0.95 (95% CI; 0.91-0.98), 0.85 (0.79-0.92), 0.81 (0.74-0.89), 0.79 (0.71-0.87), and 0.80 (0.72-0.87) (all p < 0.001), respectively. The optimal cut-off values of M2BPGi in predicting significant fibrosis, advanced fibrosis, and cirrhosis were 0.82, 0.95, and 1.23 cut-off index (COI); yielding satisfactory sensitivity, specificity, and diagnostic accuracy. The performance of M2BPGi was consistent among subgroups according to BMI, while the AUROCs of FIB-4, APRI, and NFS were remarkably decreased in patients with BMI ≥ 30 kg/m2. Patients with the PNPLA3 GG genotype had significantly higher M2BPGi than those with the CC/CG genotypes. In multivariate analysis, the independent factors associated with significant liver fibrosis were VCTE, M2BPGi, and PNPLA3 rs738409. Conclusions: Our data demonstrated that serum M2BPGi accurately assessed liver fibrosis across different BMI, indicating that this biomarker could apply to non-obese and obese patients with MASLD in clinical settings.

The histological improvement in liver fibrosis in patients with hepatitis C who achieved a sustained virological response (SVR) to direct-acting antiviral (DAA) treatment has not been comprehensively investigated. Therefore, we assessed the histological changes in liver fibrosis among patients with hepatitis C who underwent long-term follow-up after achieving SVR to treatment with DAA.

This retrospective study enrolled 71 patients with hepatitis C who achieved SVR to treatment with DAA. Changes in histological liver fibrosis and fibrosis biomarkers (hyaluronic acid, type 4 collagen 7S, Mac-2 binding protein glycosylation isomer, autotaxin, and Fibrosis-4 index) were assessed before and 5 years after treatment. Transient elastography using the FibroScan® device was performed 5 years after treatment. Advanced fibrosis and cirrhosis were defined as Ishak fibrosis scores of ≥ 4 and ≥ 5, respectively.

Histological liver fibrosis significantly regressed after SVR. Fibrosis biomarkers were significantly reduced after SVR. Transient elastography was the most helpful after evaluating the predictive performance of advanced fibrosis and cirrhosis after SVR, with an area under the receiver operating characteristic curve of 0.965 and a cut-off value of 6.75 kPa. The cut-off values of serum fibrosis biomarkers for identifying advanced fibrosis and cirrhosis after SVR were lower than those before treatment.

Long-term SVR to treatment with DAA ameliorated histological liver fibrosis. Noninvasive tests helped predict the degree of liver fibrosis after SVR, but their cut-off values should be redefined to avoid underestimation of liver fibrosis.

Understanding the dynamics of serum Mac-2 binding protein glycosylation isomer (M2BPGi) remains pivotal for hepatitis C virus (HCV) patients' post-sustained virologic response (SVR12) through direct-acting antivirals (DAAs).

We compared areas under receiver operating characteristic curves (AUROCs) of M2BPGi, FIB-4, and APRI and assess M2BPGi cutoff levels in predicting fibrosis stages of ≥F3 and F4 utilizing transient elastography in 638 patients. Variations in M2BPGi levels from pretreatment to SVR12 and their association with pretreatment alanine transaminase (ALT) levels and fibrosis stage were investigated.

The AUROCs of M2BPGi were comparable to FIB-4 in predicting ≥F3 (0.914 vs 0.902, P = 0.48) and F4 (0.947 vs 0.915, P = 0.05) but were superior to APRI in predicting ≥F3 (0.914 vs 0.851, P = 0.001) and F4 (0.947 vs 0.857, P < 0.001). Using M2BPGi cutoff values of 2.83 and 3.98, fibrosis stages of ≥F3 and F4 were confirmed with a positive likelihood ratio ≥10. The median M2BPGi change was -0.55. Patients with ALT levels ≥5 times ULN or ≥F3 demonstrated more pronounced median decreases in M2BPGi level compared to those with ALT levels 2-5 times ULN and <2 times ULN (-0.97 vs -0.68 and -0.44; P < 0.001) or with < F3 (-1.52 vs -0.44; P < 0.001).

Serum M2BPGi is a reliable marker for advanced hepatic fibrosis. Following viral clearance, there is a notable M2BPGi decrease, with the extent of reduction influenced by ALT levels and fibrosis stage.

Large-scale studies to assess the utility of the Mac-2 binding protein glycosylation isomer (M2BPGi) in predicting hepatic fibrosis in patients with hepatitis C virus (HCV) infection are limited. Serum M2BPGi level determination was performed in 1460 patients with HCV who received liver stiffness measurement (LSM) using transient elastography (TE). The correlation of LSM and grade of hepatic fibrosis as staged by TE with M2BPGi was assessed. Receiver operating characteristic (ROC) curves were constructed to evaluate the diagnostic power of M2BPGi for fibrosis stages of ≥F2, ≥F3, and F4. The selected M2BPGi cutoff values were chosen based on the maximal Youden index, a positive likelihood ratio (LR) ≥ 10, and a negative LR ≤ 0.1. Serum M2BPGi level was highly correlated with LSM (Pearson correlation coefficient: 0.567, p < 0.001) and hepatic fibrosis stage (Spearman’s rank correlation coefficient: 0.772, p < 0.001). The areas under ROC curves (AUROCs) of M2BPGi for ≥F2, ≥F3, and F4 were 0.865 (95% confidence interval [CI]: 0.846−0.884), 0.937 (95 % CI: 0.922−0.952), and 0.962 (95% CI: 0.951−0.972). The maximal Youden indices for ≥F2, ≥F3, and F4 were 1.72, 2.65, and 3.93. By selecting M2BPGi cutoff values with a positive LR ≥ 10 and a negative LR ≤ 0.1, clinicians were able to correctly discriminate F2, F3, and F4 in 69.1%, 77.8%, and 90.1% of patients. In conclusion, serum M2BPGi is a good diagnostic tool to predict the severity of hepatic fibrosis in patients with HCV infection.