Serum Mac-2 binding protein glycosylation isomer predicts the activation of hepatic stellate cells after liver transplantation

Diagnostic Performance of Serum Mac-2-Binding Protein Glycosylation Isomer as a Fibrosis Biomarker in Non-Obese and Obese Patients with MASLD

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.

Value of Mac-2 Binding Protein Glycosylation Isomer (M2BPGi) in Assessing Liver Fibrosis in Metabolic Dysfunction-Associated Liver Disease: A Comprehensive Review of its Serum Biomarker Role

Metabolic Dysfunction-Associated Fatty Liver Disease (MAFLD) is a broad condition characterized by lipid accumulation in the liver tissue, which can progress to fibrosis and cirrhosis if left untreated. Traditionally, liver biopsy is the gold standard for evaluating fibrosis. However, non-invasive biomarkers of liver fibrosis are developed to assess the fibrosis without the risk of biopsy complications. Novel serum biomarkers have emerged as a promising tool for non-invasive assessment of liver fibrosis in MAFLD patients. Several studies have shown that elevated levels of Mac-2 binding protein glycosylation isomer (M2BPGi) are associated with increased liver fibrosis severity in MAFLD patients. This suggests that M2BPGi could serve as a reliable marker for identifying individuals at higher risk of disease progression. Furthermore, the use of M2BPGi offers a non-invasive alternative to liver biopsy, which is invasive and prone to sampling errors. Overall, the usage of M2BPGi in assessing liver fibrosis in MAFLD holds great promise for improving risk stratification and monitoring disease progression in affected individuals. Further research is needed to validate its utility in clinical practice and establish standardized protocols for its implementation.

Evaluation of Mac-2 binding protein glycosylation isomer (M2BPGi) as a diagnostic marker for staging liver fibrosis: a meta-analysis

Objective

This study aimed to assess the accuracy of Mac-2 binding protein glycosylation isomer (M2BPGi) in predicting the stage of liver fibrosis.

Methods

Articles published until October 10, 2023, were searched in the PubMed, Embase, Web of Science, and Cochrane Library databases. Pooled sensitivity, specificity, diagnostic odds ratio (DOR), summary receiver-operator curves (SROC), and Spearman's rank correlation coefficient were used to examine the accuracy of M2BPGi in predicting the stage of liver fibrosis. A 95% confidence interval (CI) was provided for each estimate.

Results

Twenty-four studies were included in this meta-analysis, including 3,839 patients with liver fibrosis, 409 of whom progressed to stage 4 or above. The pooled sensitivity, specificity, and area under the ROC (AUC) for M2BPGi predicting liver fibrosis ≥F3 were 0.74 (95% CI [0.65-0.82]), 0.84 (95% CI [0.76-0.89]), and 14.99 (95% CI [9.28-24.21]), respectively. The pooled sensitivity, specificity, and AUC for ≥F4 were 0.80 (95% CI [0.70-0.88]), 0.80 (95% CI [0.73-0.86]), and 16.43 (95% CI [0.84-0.90]), respectively.

Conclusion

Among different sample partitions, M2BPGi has the best diagnostic performance for liver fibrosis stage ≥4. Furthermore, the cutoff of 1-2 is more accurate than that of 0-1 or 2-3 for fibrosis ≥ F3 and ≥ F4.

Registration

CRD42023483260.

Serum Mac-2 binding protein glycosylation isomer and galectin-3 levels in adult-onset Still's disease and their association with cytokines

Background

Autoinflammation with cytokine dysregulation may be implicated in the pathophysiology of adult-onset Still's disease (AOSD); however, the relationship between galectins and cytokines in patients with active AOSD remains unknown. We aimed to examine the relationship between circulating cytokines/chemokines and galectin-3 (Gal-3) or its ligand, Mac-2 binding protein glycosylation isomer (M2BPGi), in Japanese patients with AOSD.

Methods

We recruited 44 consecutive patients diagnosed with AOSD according to the Yamaguchi criteria, 50 patients with rheumatoid arthritis (RA) as disease controls, and 27 healthy participants. Serum M2BPGi levels were directly measured using a HISCL M2BPGi reagent kit and an automatic immunoanalyzer (HISCL-5000). Serum Gal-3 concentrations were measured by enzyme-linked immunosorbent assay. The serum levels of 69 cytokines were analyzed in patients with AOSD using a multi-suspension cytokine array. We performed a cluster analysis of each cytokine expressed in patients with AOSD to identify specific molecular networks.

Results

Significant increases in the serum concentrations of Gal-3 and M2BPGi were found in the serum of patients with AOSD compared with patients with RA and healthy participants (both p <0.001). There were significant positive correlations between serum Gal-3 levels and AOSD disease activity score (Pouchot score, r=0.66, p <0.001) and serum ferritin levels. However, no significant correlations were observed between serum M2BPGi levels and AOSD disease activity scores (Pouchot score, r = 0.32, p = 0.06) or serum ferritin levels. Furthermore, significant correlations were observed between the serum levels of Gal-3 and various inflammatory cytokines, including interleukin-18, in patients with AOSD. Immunosuppressive treatment in patients with AOSD significantly reduced serum Gal-3 and M2BPGi levels (p = 0.03 and 0.004, respectively).

Conclusions

Although both Gal-3 and M2BPGi were elevated in patients with AOSD, only Gal-3 was a useful biomarker for predicting disease activity in AOSD. Our findings suggest that circulating Gal-3 reflects the inflammatory component of AOSD, which corresponds to proinflammatory cytokine induction through inflammasome activation cascades.

Clinical Implications of Serum Mac-2 Binding Protein in Patients After Living Donor Liver Transplantation for Biliary Atresia

BACKGROUND

Patients who undergo pediatric living donor liver transplantation (LDLT) sometimes develop graft fibrosis. Recently, Mac-2 binding protein glycosylation-modified isomer (M2BPGi) was developed as a new marker of hepatic fibrosis progression. We performed this study to examine the relationship between serum M2BPGi levels and liver histologic findings in patients after LDLT for biliary atresia.

METHODS

Patients aged <19 years who underwent LDLT for biliary atresia at our institution and followed up for at least 1 year after LDLT were eligible. There were 56 patients in this study. Pathologic findings of the last available biopsy were assessed. Portal vein (PV) stenosis was confirmed with angiography. M2BPGi levels were compared with pathologic fibrosis scores and PV stenosis findings.

RESULTS

The mean age at transplant was 4.3 years. The mean observation period was 8.6 years. In terms of the degree of liver fibrosis, F0 was observed in 7 patients, F1 in 36, and F2 in 13. The median serum M2BPGi value was 0.8 cut-off index (COI) overall and 0.60 COI for F0, 0.74 COI for F1, and 1.07 COI for F2. The mean M2BPGi value in F2 was higher than that in F0 (P = .016) and F1 (P = .012). Mean serum M2BPGi values were 1.57 COI (0.29 COI) in patients with PV complications (n = 5) and 0.72 COI in patients without PV complications (n = 51) (P = .0001).

CONCLUSION

M2BPGi is a novel marker for liver fibrosis in patients after pediatric LDLT. It is especially useful for follow-up of pediatric patients after LDLT to support liver biopsy interpretation.

Clinical Significance of the Mac-2 Binding Protein Glycosylated Isomer as a Surrogate Marker of Graft Fibrosis After Pediatric Liver Transplantation

BACKGROUND

After pediatric liver transplantation, liver fibrosis may occur during long-term follow-up. Noninvasive markers for assessing this liver fibrosis are desired. Mac-2 binding protein glycosylated isomer (M2BPGi) has recently been reported as a useful biomarker for liver fibrosis. However, its usefulness in the pediatric population is yet to be established. This study investigated the clinical significance of M2BPGi levels as a surrogate marker of graft fibrosis after pediatric liver transplantation.

METHODS

We retrospectively identified 96 patients who underwent pediatric liver transplantation at our institution between 1991 and 2015. The association between M2BPGi levels and other fibrosis markers was analyzed in 60 patients in whom fibrosis markers were measured. The association between fibrosis marker levels and graft fibrosis was assessed in 42 patients who underwent biopsies between 2016 and 2022.

RESULTS

The M2BPGi levels were statistically correlated with the hyaluronic acid and type-IV collagen levels. None of the fibrosis markers were significantly associated with liver graft fibrosis, although the levels of these markers were slightly higher in patients with severe liver fibrosis than in those with mild fibrosis.

CONCLUSIONS

The M2BPGi levels had a limited ability to assess liver graft fibrosis after pediatric liver transplantation, similar to other fibrosis markers. Further studies with larger cohorts are required to validate these findings externally.

Hepatic stellate cell as a Mac-2-binding protein-producing cell in patients with liver fibrosis

BACKGROUND

Mac-2 binding protein (M2BP) glycosylated isomer (M2BPGi) is a serum marker of liver fibrosis; M2BPGi is a glycosylated form of M2BP. Hepatocytes and hepatic stellate cells (HSCs) have been studied to determine the source of M2BP. This study proposes to identify the origin of M2BP in fibrotic liver.

METHODS

Using liver fibrosis tissue specimens from 15 patients with liver cancer, M2BP mRNA and M2BP were detected by in situ hybridization and immunohistochemistry, respectively. The expression levels of M2BP mRNA were evaluated with scores of 3, 2, and 1. Fluorescent in situ hybridization was carried out to evaluate the distribution of M2BP mRNA and the activated-HSC marker αSMA mRNA; multicolor fluorescent immunohistochemistry was used for protein localization of M2BP, αSMA, and CD68. The Kruskal-Wallis test analyzed the relationship between M2BP mRNA expression and existing serum fibrosis markers.

RESULTS

M2BP mRNA was expressed in spindle-shaped cells along the fibrous septa and in the perisinusoidal area of the fibrotic liver. The HSC markers αSMA mRNA and M2BP mRNA were colocalized in the spindle-shaped cells; on the protein level, M2BP was expressed in Kupffer cells. M2BP mRNA expression was positively correlated with serum M2BPGi levels. Aspartate transaminase-to-platelet ratio index, Fibrosis-4, hyaluronic acid, and the 15-minute indocyanine green retention rate were significantly correlated with M2BP mRNA expression.

CONCLUSIONS

M2BP mRNA transcription in fibrotic liver was primarily observed in HSCs but not at the M2BP level, which suggests that HSCs might produce and introduce M2BP to Kupffer cells and serum.

Sarcoidosis-lymphoma syndrome with portal hypertension: diagnostic clues and approach

Sarcoidosis-lymphoma syndrome associated with portal hypertension is very rare. A 68-year-old female presented with a 5 kg weight loss in 6 months. Soluble interleukin-2 receptor activity was increased and total platelet count was decreased. Contrast-enhanced computed tomography showed the presence of hepatosplenomegaly and a 3 cm-sized tumor in segment 3 of the liver. The hepatic venous catheterization showed mild portal hypertension. On fluorodeoxyglucose-positron emission tomography/computed tomography, progressive malignant lymphoma was suspected. However, bone marrow biopsy showed multiple noncaseating granulomas. A laparoscopic liver biopsy revealed that the liver tumor had features of Hodgkin lymphoma. There were multiple noncaseating epithelioid granulomas in the portal tracts of the liver. Splenectomy for splenomegaly and partial hepatectomy for the liver tumor were performed. Pathological examination of the resected specimens revealed multiple noncaseating epithelioid granulomas in the liver and spleen. Histopathology of the liver tumor confirmed classic Hodgkin lymphoma with mixed cellularity. We conclude that hepatic venous catheterization, positron emission tomography/computed tomography, and pathological examinations of bone marrow, liver, and spleen are crucial for the diagnosis of sarcoidosis-lymphoma syndrome associated with portal hypertension.

Utility of Mac-2 Binding Protein Glycosylation Isomer to Evaluate Graft Status After Liver Transplantation

Mac-2 binding protein glycosylation isomer (M2BPGi) is a novel liver fibrosis biomarker, but there are few studies on M2BPGi in liver transplantation (LT) recipients. This study aimed to evaluate the utility of M2BPGi measurement in LT recipients. We collected the clinicopathological data of 233 patients who underwent a liver biopsy at Kyoto University Hospital after LT between August 2015 and June 2019. The median values of M2BPGi in patients with METAVIR fibrosis stages F0, F1, F2, and ≥F3 were 0.61, 0.76, 1.16, and 1.47, respectively, whereas those in patients with METAVIR necroinflammatory indexes A0, A1, and ≥A2 were 0.53, 1.145, and 2.24, respectively. Spearman rank correlation test suggested that the necroinflammatory index had a stronger correlation to the M2BPGi value than the fibrosis stage. The area under the receiver operating characteristic curve of M2BPGi to predict ≥A1 was 0.75, which was significantly higher than that of any other liver fibrosis and inflammation marker. Patients with a rejection activity index (RAI) of ≥3 had a higher M2BPGi value than those with RAI ≤ 2 (P = 0.001). Patients with hepatitis C virus viremia had a higher M2BPGi value than sustained virological responders or those with other etiologies. In conclusion, the present study demonstrated that M2BPGi values are more strongly influenced by necroinflammatory activity and revealed M2BPGi, which has been thought to be a so-called fibrosis marker, as a disease activity marker in transplant recipients. M2BPGi measurement may be useful to detect early stage liver inflammation that cannot be detected by routine blood examination of LT recipients.

Serum Mac-2 binding protein glycosylation isomer as a biomarker of fibrosis in living donor liver transplant graft

INTRODUCTION

Non-invasive assessment of graft fibrosis is important in liver transplantation. Mac-2 binding protein glycosylation isomer (M2BPGi) has been reported as a diagnostic marker for this purpose, and thus, this predictive ability of M2BPGi was assessed in this study.

PATIENTS AND METHODS

In this retrospective study, 236 patients who received living donor liver transplantation (LDLT) from August 1997 to March 2017 were enrolled. Among them, 94 biopsy patients were analyzed. Further, the predictive ability of fibrotic biopsy using M2BPGi, Fibroscan, and Fib-4 index was compared.

RESULTS

Of 94 LDLT patients (53 men, 41 women), the median ages of recipients and donors were 57.5 and 33.0 years, respectively. The median M2BPGi values in patients with F0 (n = 11), F1 (n = 38), F2 (n = 35), and F3/4 (n = 10) were 0.680, 0.760, 1.240, and 4.110 COI, respectively. There were significant correlations between the fibrotic stage and M2BPGi levels (Kruskal-Wallis test, P < .0001). The area under the ROC curve for the diagnosis of F ≥ 2 in M2BPGi was 0.778, which was superior to Fibroscan (0.701) and Fib-4 index (0.639).

CONCLUSION

M2BPGi is an accurate, non-invasive detection method for significant fibrosis after LDLT.

Clinical Utility of Mac-2 Binding Protein Glycosylation Isomer in Chronic Liver Diseases

An accurate evaluation of liver fibrosis is clinically important in chronic liver diseases. Mac-2 binding protein glycosylation isomer (M2BPGi) is a novel serum marker for liver fibrosis. In this review, we discuss the role of M2BPGi in diagnosing liver fibrosis in chronic hepatitis B and C, chronic hepatitis C after sustained virologic response (SVR), and nonalcoholic fatty liver disease (NAFLD). M2BPGi predicts not only liver fibrosis but also the hepatocellular carcinoma (HCC) development and prognosis in patients with chronic hepatitis B and C, chronic hepatitis C after SVR, NAFLD, and other chronic liver diseases. M2BPGi can also be used to evaluate liver function and prognosis in patients with cirrhosis. M2BPGi levels vary depending on the etiology and the presence or absence of treatment. Therefore, the threshold of M2BPGi for diagnosing liver fibrosis and predicting HCC development has to be adjusted according to the background and treatment status.

Wisteria floribunda agglutinin-positive Mac-2-binding protein as a diagnostic biomarker in liver cirrhosis: an updated meta-analysis

Wisteria floribunda agglutinin-positive Mac-2-binding protein (WFA+-M2BP) had been suggested as a possible glycobiomarker for assessing liver fibrosis. Here, we conducted this updated meta-analysis to systematically investigate the predictive accuracy of WFA+-M2BP for diagnosing liver fibrosis and hepatocellular carcinoma (HCC) by comparing with multiple non-invasive indicators. We searched relevant literatures from Pubmed, Web of Science, EMBASE and Cochrane Library and enrolled 36 eligible studies involving 7,362 patients. Summary results were calculated using bivariate random effects model. The pooled sensitivities, specificities and areas under the summary receiver operating characteristic curves (AUSROCs) of WFA+-M2BP for identifying mild fibrosis, significant fibrosis, advanced fibrosis, cirrhosis, and HCC were 0.70/0.68/0.75, 0.71/0.75/0.79, 0.75/0.76/0.82, 0.77/0.86/0.88, and 0.77/0.80/0.85, respectively. The accuracy of WFA+-M2BP was strongly affected by etiology and it was not better than other non-invasive indicators for predicting early fibrosis. It showed similar diagnostic performance to hyaluronic acid and FibroScan for cirrhosis, but was equivalent to α-fetoprotein for HCC. In conclusion, WFA+-M2BP was suitable to diagnose late stage of liver fibrosis, especially cirrhosis. Individual cutoff value of WFA+-M2BP could be used to grade liver fibrosis in different etiology. Combined diagnostic model was suggested to improve its predictive accuracy for HCC.

Increased Mac-2 binding protein glycan isomer in patients at risk for late nonrelapse mortality after HSCT

Macrophages play a crucial role in the pathogenesis of chronic graft-versus-host disease (cGVHD). We hypothesized that galectin-3, Mac-2 binding protein (M2BP), or Wisteria floribunda agglutinin (WFA)+-M2BP, called M2BP glycan isomer (M2BPGi), might contribute to macrophage activation, and fibrosis would be associated with cGVHD and nonrelapse mortality (NRM) in hematopoietic stem cell transplant (HSCT) recipients. Patients who underwent their first allogeneic HSCT and survived for >180 days without relapse were included. The predictive potential of the 3 markers for NRM was assessed using the discovery cohort (n = 55) and validation cohort 1 (n = 55). When we used the threshold determined by a receiver operating characteristics curve analysis in the discovery cohort, only M2BPGi at day +180 was significantly associated with a higher NRM in the discovery cohort (15.0% vs 0.0% at 5 years, P = .001) and in validation cohort 1 (34.0% vs 8.4% at 5 years, P = .014). This result was confirmed in validation cohort 2 (n = 50). M2BPGi was not increased in healthy individuals or in patients who received autologous HSCT. In the entire cohort (N = 110), M2BPGi was significantly related to liver cGVHD but not to other organ involvement. In multivariate analyses, M2BPGi was an independent risk factor for NRM. In immunofluorescence staining of autopsy cases, WFA+-M2BP-positive macrophages were found only in the liver sections with cGVHD. In conclusion, M2BPGi could be a promising predictor of late NRM after HSCT and was associated with liver involvement.

Elevation of Mac-2 binding protein glycosylation isomer after hepatectomy is associated with post-hepatectomy liver failure, total Pringle time, and renal dysfunction

BACKGROUND

Mac-2 binding protein glycosylation isomer (M2BPGi) is a novel serum glycomarker used to assess liver fibrosis. However, it has been reported that M2BPGi is likely to reflect other factors not limited to liver fibrosis.

METHODS

We retrospectively analyzed 79 patients with liver tumors who underwent liver resection. M2BPGi was measured within 1 week before operation and almost 1 month after operation. We introduced a value termed the "ΔM2BPGi ratio" (=M2BPGiafter operation/M2BPGibefore operation), and analyzed factors that influenced the ΔM2BPGi ratio.

RESULTS

The median value of the ΔM2BPGi ratio was 1.28 (range, 0.36-5.68). In 64 patients (81.0%), the cutoff index values of M2BPGi were elevated approximately 1 month after operation, especially in patients who experienced post-hepatectomy liver failure (PHLF). Multiple linear regression showed total Pringle time, PHLF grade ≥B, and preoperative value of creatinine were significant predictors of the ΔM2BPGi ratio. The mean values of the ΔM2BPGi ratio were 1.37 ± 0.07, 1.52 ± 0.22, and 2.94 ± 0.30 for PHLF grade 0, grade A, and grade B, respectively, resulting in statistically significant differences by the Kruskal-Wallis test (P = 0.022).

CONCLUSIONS

Total Pringle time, PHLF grade ≥B, and preoperative creatinine significantly influenced the elevation of M2BPGi almost 1 month after liver resection. This study strongly affirms the previous suggestion that M2BPGi is likely to reflect other factors not limited to liver fibrosis.

Peritransplant kinetics of Mac-2-binding protein glycosylation isomer levels in living donor liver transplantation: its implication of posttransplant small-for-size syndrome

Background

Wisteria floribunda agglutinin positive human Mac-2 binding protein glycosylation isomer (M2BPGi) has recently developed as a noninvasive serum marker of liver fibrosis. Liver transplant candidates usually have high serum levels of M2BPGi due to advanced cirrhosis. The aim of the present study was to elucidate the kinetics of serum M2BPGi after liver transplantation and the relationships between the level of M2BPGi and graft function.

Methods

Fifteen recipients who underwent living donor liver transplantation (LDLT) between June 2015 and January 2016 and whose pretransplant, postoperative day (POD) 1, POD 3, and POD 7 sera were available for measuring M2BPGi were enrolled in this study. Small-for-size syndrome (SFSS) was defined as the presence of cholestasis (total bilirubin >10 mg/dL) on POD 7 and intractable ascites (>1 L/day on POD 14 or >500 ml/day on POD 28) without other specific causes.

Results

The median of pretransplant M2BPGi was 9.75 cutoff index (C.O.I.) (range, 3.04-24.49). There was neither any correlation between pretransplant M2BPGi and Model for End-Stage Liver Disease scores (r=0.416, P=0.123) nor Child-Turcotte-Pugh scores (r=-0.221, P=0.428). The levels of M2BPGi dramatically decreased after LDLT (median; 1.48 on POD 1, 1.47 on POD 3, 1.49 on POD 7). However, serum levels of M2BPGi rose again on POD 7 in some recipients and all 4 recipients with serum levels of M2BPGi exceeding 3.00 C.O.I. succumbed to SFSS later. When the cutoff of M2BPGi on POD 7 for predicting SFSS was determined to be 3.06 according to its receiver operating characteristic curve, both the sensitivity and the specificity for predicting later SFSS were 100%.

Conclusions

The levels of M2BPGi dramatically decreased after LDLT. A re-rise of M2BPGi predicted later development of SFSS.