Serum cytokine profiles and Mac-2 binding protein glycosylation isomer (M2BPGi) level in patients with autoimmune hepatitis

Clinical validation of preoperative serum markers for liver fibrosis in living donor liver transplantation recipients

PURPOSE

To validate the reliability of fibrosis markers as predictors of graft survival in living donor liver transplantation (LDLT) recipients.

METHODS

We reviewed data retrospectively, from 163 patients who underwent adult LDLT with preoperative measurements of type IV collagen (CIV), Mac-2 binding protein glycosylation isomer (M2BPGi), and hyaluronic acid (HA). Patients were divided into high and low groups for each biomarker, based on optimal cutoff values, and graft loss within 6 months was evaluated in each group.

RESULTS

The high CIV level group showed significantly lower 6-month graft survival rates and significantly higher rates of postoperative sepsis and sepsis from pneumonia. However, the groups with high and low M2BPGi levels and those with high and low HA levels did not show significant differences in 6-month graft survival rates or rates of postoperative sepsis. Multivariate analysis revealed that a CIV level ≥ 590 was a significant predictor of graft loss within 6 months, postoperative sepsis, and sepsis from pneumonia.

CONCLUSION

Unlike other fibrosis markers, preoperative CIV levels can predict graft survival, postoperative sepsis, and sepsis from pneumonia after LDLT.

Elevated A2F bisect N-glycans of serum IgA reflect progression of liver fibrosis in patients with MASLD

BACKGROUND

Advanced liver fibrosis in cases of metabolic dysfunction-associated steatotic liver disease (MASLD) leads to cirrhosis and hepatocellular carcinoma. The current gold standard for liver fibrosis is invasive liver biopsy. Therefore, a less invasive biomarker that accurately reflects the stage of liver fibrosis is highly desirable.

METHODS

This study enrolled 269 patients with liver biopsy-proven MASLD. Patients were divided into three groups (F0/1 (n = 41/85), F2 (n = 47), and F3/4 (n = 72/24)) according to fibrosis stage. We performed serum N-glycomics and identified glycan biomarker for fibrosis stage. Moreover, we explored the carrier proteins and developed a sandwich ELISA to measure N-glycosylation changes of carrier protein.

RESULTS

Comprehensive N-glycomic analysis revealed significant changes in the expression of A2F bisect and its precursors as fibrosis progressed. The sum of neutral N-glycans carrying bisecting GlcNAc and core Fuc (neutral sum) had a better diagnostic performance to evaluate advanced liver fibrosis (AUC = 0.804) than conventional parameters (FIB4 index, aspartate aminotransferase-to-alanine aminotransferase ratio (AAR), and serum level of Mac-2-binding protein glycol isomer (M2BPGi). The combination of the neutral sum and FIB4 index enhanced diagnostic performance (AUC = 0.840). IgM, IgA, and complement C3 were identified as carrier proteins with A2F bisect N-glycan. A sandwich ELISA based on N-glycans carrying bisecting GlcNAc and IgA showed similar diagnostic performance than the neutral sum.

CONCLUSIONS

A2F bisect N-glycan and its precursors are promising candidate biomarkers for advanced fibrosis in MASLD patients. Analysis of these glycan alterations on IgA may have the potential to serve as a novel ELISA diagnostic tool for MASLD in routine clinical practice.

CLINICAL TRIAL NUMBER

UMIN000030720.

Comparison of Efficacy between Pemafibrate and Omega-3-Acid Ethyl Ester in the Liver: the PORTRAIT Study

AIM

No pharmacotherapeutic treatment has been established for metabolic dysfunction-associated steatotic liver disease (MASLD) and metabolic dysfunction-associated steatohepatitis (MASH). This trial compared the effects of pemafibrate and omega-3-acid ethyl ester on hepatic function in patients with hypertriglyceridemia complicated by MASLD.

METHODS

Patients with hypertriglyceridemia complicated by MASLD were enrolled, randomly assigned to the pemafibrate or omega-3-acid ethyl ester group, and followed for 24 weeks. The primary endpoint was the change in alanine aminotransferase (ALT) from baseline to week 24. The secondary endpoints included other hepatic enzymes, lipid profiles, and hepatic fibrosis biomarkers.

RESULTS

A total of 80 patients were enrolled and randomized. The adjusted mean change in ALT from baseline to week 24 was significantly lower in the pemafibrate group (-19.7±5.9 U/L) than in the omega-3-acid ethyl ester group (6.8±5.5 U/L) (intergroup difference, -26.5 U/L; 95% confidence interval, -42.3 to -10.7 U/L; p=0.001). Pemafibrate significantly improved the levels of other hepatic enzymes (aspartate aminotransferase and gamma-glutamyl transpeptidase), lipid profiles (triglycerides, total cholesterol, high-density lipoprotein cholesterol, and non-high-density lipoprotein cholesterol), and hepatic fibrosis biomarkers (Mac-2 binding protein glycan isomer and Fibrosis-4 index). No cases of discontinuation due to adverse drug reactions were identified in either group, and there were no safety concerns.

CONCLUSIONS

Pemafibrate is recommended over omega-3-acid ethyl ester for lipid management and MASLD treatment in patients with hypertriglyceridemia complicated by MASLD. The study results may contribute to the development of future treatment strategies for patients with MASLD/MASH.

The value of serum Mac-2 binding protein glycosylation isomer in the diagnosis of liver fibrosis: a systematic review and meta-analysis

Background

The early detection and intervention of liver fibrosis (LF) in patients with chronic liver disease is critical to their management. The accuracy of serum Mac-2 binding protein glycosylation isomer (M2BPGi) in the diagnosis of LF remains controversial. This study aimed to comprehensively assess the value of serum M2BPGi in diagnosing LF.

Methods

The PubMed, Embase, MEDLINE, Web of Science, and Cochrane Library databases were searched. The effect values were combined using a random-effects model. Meta-regression and subgroup analysis were used to explore the sources of heterogeneity. In addition, publication bias assessment and sensitivity analysis were conducted.

Results

This study includes 12 studies with 2,416 patients. The pooled sensitivity, specificity, and AUROC of M2BPGi in the diagnosis of significant fibrosis (≥F2) were 0.65 (95% CI: 0.57-0.71), 0.79 (95% CI: 0.72-0.84), and 0.78 (95% CI: 0.74-0.81), respectively, while those for predicting extensive fibrosis (≥F3) were 0.76 (95% CI: 0.71-0.80), 0.75 (95% CI: 0.68-0.81), and 0.81 (95% CI: 0.77-0.84). Sensitivity analysis indicated stable results in this study. The disease type, cut-off values, study country, average age, and male proportion were the sources of heterogeneity in diagnosing significant fibrosis of M2BPGi (p < 0.05). Sample size, disease type, study country, publication year, cut-off values, average age, and male proportion were important sources of heterogeneity in diagnosing extensive fibrosis (p < 0.05).

Conclusion

Serum M2BPGi has good diagnostic performance for significant fibrosis and extensive fibrosis in patients with chronic hepatitis B (CHB), chronic hepatitis C (CHC), or nonalcoholic fatty liver disease (NAFLD) and is an effective, non-invasive, and convenient marker.

Systematic Review Registration

https://inplasy.com/inplasy-2023-10-0086/.

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.

New chemiluminescent enzyme immunoassay for quantitative measurement of Mac-2 binding protein glycosylation isomer in chronic liver disease

BACKGROUND

This study aimed to evaluate the quantitative measurement of Mac-2 binding protein glycosylation isomer (M2BPGi) levels using the new chemiluminescent enzyme immunoassay.

METHODS

The data of a total of 347 patients with hepatitis C virus (HCV) infection and 150 health volunteers from 13 locations in Japan were evaluated. The quantitative system for measuring M2BPGi-Qt levels was based on a new chemiluminescent enzyme immunoassay. We evaluated the reproducibility and quantitation range in quantitative M2BPGi-Qt measurement. We also investigated the confidence ratio of M2BPGi-Qt levels measured by the new quantitative system to M2BPGi levels measured by the current semi-quantitative system for validating the clinical utility of the new method.

RESULTS

The reproducibility of M2BPGi-Qt in HCV samples with negative, positive 1+, and positive 2+ was 0.77 ± 0.02 AU/mL, 2.25 ± 0.03 AU/mL, and 6.55 ± 0.21 AU/mL, respectively, and the corresponding coefficient of variation (CV)s were 2.1%, 1.3%, and 3.2%, respectively. The range of quantification assessment resulted that all CVs showed less than 5% in investigated range. Sample stability testing found that the mean percentage difference between the pre- and post-storage values of 6 samples ranged between 96.2 and 103.9%. The correlation coefficient between M2BPGi and M2BPGi-Qt in patients with HCV and the healthy volunteers was 0.986 and 0.991, respectively. M2BPGi-Qt could be quantitatively assessed in a patient with over 20 C.O.I.

CONCLUSION

Compared with qualitative methods, the M2BPGi quantitative measurement system could provide a numerical value unaffected by interpretation bias, and measurements are more precise at high M2BPGi levels.

Pre-sarcopenia and Mac-2 binding protein glycosylation isomer as predictors of recurrence and prognosis of early-stage hepatocellular carcinoma

BACKGROUND

The Mac-2 binding protein glycosylation isomer (M2BPGi), a fibrosis marker in various liver diseases, is reportedly a prognostic marker in patients with hepatocellular carcinoma (HCC) who underwent hepatectomy.

AIM

To evaluate whether the M2BPGi value, M2BP, and pre-sarcopenia before radiofrequency ablation (RFA) could be useful recurrence and prognostic markers in patients with early-stage HCC.

METHODS

In total, 160 patients with early-stage primary HCC treated with RFA were separately analyzed as hepatitis C virus (HCV)-positive and HCV-negative. Factors contributing to recurrence and liver-related death, including M2BP, M2BPGi, and skeletal muscle mass index, were statistically analyzed. Eighty-three patients were HCV-positive and 77 were HCV-negative.

RESULTS

In HCV-positive patients, only des-γ-carboxy-prothrombin ≥ 23 mAU/mL was a significant poor prognostic factor affecting survival after RFA. In HCV-negative patients, M2BPGi ≥ 1.86 cutoff index was significantly associated with tumor recurrence, while M2BP was not. M2BPGi ≥ 1.86 cutoff index (hazard ratio, 4.89; 95% confidence interval: 1.97-12.18; P < 0.001) and pre-sarcopenia (hazard ratio, 3.34, 95% confidence interval: 1.19-9.37; P = 0.022) were independent significant poor prognostic factors in HCV-negative patients.

CONCLUSION

In HCV-negative patients with primary HCC treated with RFA, lower M2BPGi contributed to a lower tumor recurrence rate and longer survival period. Pre-sarcopenia contributed to the poor prognosis independently in HCV-negative patients. These factors might be useful recurrence and prognostic markers for early-stage primary HCC.

Serum Biomarkers for Autoimmune Hepatitis Type 1: the Case for CD48 and a Review of the Literature

In autoimmune hepatitis (AIH), the persisting inflammation contributes to fibrosis progression, for which conventional biochemical markers manifest relatively unsatisfactory prediction. Herein, we assessed the value of serum CD48 (sCD48) as an indicator for inflammation and fibrosis in AIH type 1. The levels of sCD48 were detected first in an exploratory cohort using ELISA. In this cohort, compared with healthy controls (4.90 ng/mL, P < 0.0001), primary biliary cholangitis (7.32 ng/mL, P < 0.0001), and non-alcoholic fatty liver disease (7.76 ng/mL, P < 0.0001), sCD48 levels were elevated in AIH (12.81 ng/mL) and correlated with histological inflammation and fibrosis. Further using multivariate logistic regression analysis, sCD48 was identified as an independent predictor for both significant inflammation (G3-4) and advanced fibrosis (S3-4). Two predictive scores, based on sCD48, were constructed for diagnosing significant inflammation and advanced fibrosis (sCD48-AIH-SI and sCD48-AIH-AF, respectively). Using these data as a premise, predictive abilities were subsequently evaluated and verified in a validation cohort. In the exploratory cohort, the area under the receiver operating characteristic curve of sCD48 and sCD48-AIH-SI, for significant inflammation, were 0.748 and 0.813, respectively. Besides, during treatment follow-up, sCD48 levels gradually decreased from immunosuppression initiation to re-evaluation biopsy, in parallel with aspartate transaminase, total sera IgG, and fibrosis-4 score. For AIH patients in a re-evaluation biopsy cohort, sCD48 could predict significant fibrosis (S2-4). Further using immunohistochemistry, hepatic CD48 expression was elevated in AIH patients and decreased after treatment. In conclusion, sCD48 and sCD48-based predictive scores predict histological inflammation and fibrosis in AIH-1. Detecting sCD48 might help in the clinical management of AIH.

Investigation of immune complexes formed by mitochondrial antigens containing a new lipoylated site in sera of primary biliary cholangitis patients

Primary biliary cholangitis (PBC) is characterized by the presence of serum anti-mitochondrial autoantibodies (AMAs). To date, four antigens among the 2-oxo-acid dehydrogenase complex family, which commonly have lipoyl domains as an epitope, have been identified as AMA-corresponding antigens (AMA-antigens). It has recently been reported that AMAs react more strongly with certain chemically modified mimics than with the native lipoyl domains in AMA-antigens. Moreover, high concentrations of circulating immune complexes (ICs) in PBC patients have been reported. However, the existence of ICs formed by AMAs and their antigens has not been reported to date. We hypothesized that AMAs and their antigens formed ICs in PBC sera, and analyzed sera of PBC and four autoimmune diseases (Sjögren's syndrome, systemic lupus erythematosus, systemic scleroderma, and rheumatoid arthritis) using immune complexome analysis, in which ICs are separated from serum and are identified by nano-liquid chromatography-tandem mass spectrometry. To correctly assign MS/MS spectra to peptide sequences, we used a protein-search algorithm that including lipoylation and certain xenobiotic modifications. We found three AMA-antigens, the E2 subunit of the pyruvate dehydrogenase complex (PDC-E2), the E2 subunit of the 2-oxo-glutarate dehydrogenase complex (OGDC-E2) and dihydrolipoamide dehydrogenase binding protein (E3BP), by detecting peptides containing lipoylation and xenobiotic modifications from PBC sera. Although the lipoylated sites of these peptides were different from the well-known sites, abnormal lipoylation and xenobiotic modification may lead to production of AMAs and the formation ICs. Further investigation of the lipoylated sites, xenobiotic modifications, and IC formation will lead to deepen our understanding of PBC pathogenesis.

Recent updates on the management of autoimmune hepatitis

Autoimmune hepatitis (AIH) is an immunoinflammatory chronic liver disease with dynamic and rather heterogeneous disease manifestations. A trend of increasing prevalence of AIH has been observed worldwide, along with a relative increase in the percentage of male patients. AIH is characterized and diagnosed based on serum biochemistry and liver histology: elevated aminotransferases and serum immunoglobulin G (IgG), the presence of serum anti-nuclear antibody or anti-smooth muscle antibody, and interface lympho-plasmacytic hepatitis. Clinical manifestations differ among disease subtypes with distinct time-frames, i.e., AIH with a chronic insidious onset, and acute-onset AIH (the diagnosis of which is often challenging due to the lack of typical serum findings). The absence of disease-specific biomarkers or histological findings may expand the disease phenotype into drug-induced AIH-like liver injury. Corticosteroids and azathioprine are recommended first-line treatments for AIH. The complete normalization of aminotransferases and serum IgG is an essential treatment response to ensure long-term overall survival. An incomplete response or intolerance to these drugs is considered an indication for second-line treatment, especially with mycophenolate mofetil. Life-long maintenance treatment is required for the majority of patients, but the few who achieve prolonged and stringent biochemical remission with lower alanine aminotransferase and IgG within the normal range may be able to discontinue the medications. In the future, the quality of life of AIH patients should be managed by personalized medicine, including the appropriate selection and dosing of first-line therapy and perhaps alternating with potential therapeutics, and the prediction of the success of treatment withdrawal.

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.

Serum levels of mac-2 binding protein are associated with diabetic microangiopathy and macroangiopathy in people with type 2 diabetes

INTRODUCTION

Non-alcoholic fatty liver disease is reportedly associated with type 2 diabetes and progressive liver fibrosis, as evaluated by transient elastography, and has been linked with micro- and macroangiopathy in people with type 2 diabetes. The purpose of this cross-sectional study was to investigate the association between serum mac-2 binding protein glycosylation isomer (M2BPGi) levels and diabetic complications in people with type 2 diabetes.

RESEARCH DESIGN AND METHODS

Serum M2BPGi levels were measured in terms of cut-off index (C.O.I.) units. Urinary albumin excretion (UAE) was calculated and nephropathy was graded as normoalbuminuria, microalbuminuria, or macroalbuminuria. Retinopathy was divided into three groups: no-diabetic retinopathy (NoDR), non-proliferative-diabetic retinopathy (NPDR), or proliferative-diabetic retinopathy (PDR) .

RESULTS

The mean age for the 363 studied subjects (212 males) was 66.4±10.6 years, the median serum M2BPGi level was 0.77 (0.57-1.04) C.O.I., and the median UAE was 22 (9-82.1) mg/g creatinine. M2BPGi levels in microalbuminuria (0.83 (0.61 to 1.18) C.O.I.) and macroalbuminuria (0.88 (0.67 to 1.22) C.O.I.) cases were higher than those in normoalbuminuria cases (0.71 (0.54 to 0.92) C.O.I.). M2BPGi levels in NPDR (0.93 (0.68 to 1.28) C.O.I.) and PDR (0.95 (0.71 to 1.31) C.O.I.) cases were higher than in cases with NoDR (0.73 (0.56 to 0.99) C.O.I.). Furthermore, M2BPGi levels in subjects with a history of cardiovascular diseases were higher than in those with no such history (0.82 (0.65 to 1.22) vs 0.76 (0.55 to 1.03) C.O.I., p=0.019). The logarithm of (M2BPGi+1) was associated with the logarithm of UAE values after adjusting for covariates (standardized β=0.107, p=0.031).

CONCLUSIONS

This study reveals a close association between serum M2BPGi levels and diabetic microangiopathy and macroangiopathy in people with type 2 diabetes. The results also show that liver fibrosis, evaluated by M2BPGi, is independently associated with an increased risk of albuminuria.

Autoimmune Hepatitis: 2019 Update

Autoimmune hepatitis (AIH) is a chronic inflammatory liver disease, characterized by the elevation of aminotransferases, presence of anti-nuclear antibody or anti-smooth muscle antibody, elevated immunoglobulin G (IgG), and interface hepatitis/plasma-lymphocytic inflammation based on histology. Recent epidemiological studies have indicated an increasing trend in the prevalence of AIH worldwide, especially in male patients; this trend may suggest the alteration of environmental triggers of disease onset over time. As no disease-specific biomarker or histological finding is currently available, AIH requires a clinical diagnosis, and a validated diagnostic scoring system with acceptable specificity and sensitivity has been proposed. Regarding treatment, corticosteroids and azathioprine are recommended, and in those who exhibit an incomplete response or those who are intolerant to these drugs, second-line therapy, such as mycophenolate mofetil, is considered. Overall, the long-term outcome is excellent in patients with complete biochemical responses, while life-long maintenance treatment may be required since the cessation of immunosuppressive agents frequently leads to the relapse of the disease. Acute-onset AIH does occur, and the diagnosis is very challenging due to the lack of serum autoantibodies or elevated IgG. The unmet needs include earlier diagnosis, intervention with disseminated clinical practice guidelines, and recognition and improvement of patients’ health-related quality of life with the development of novel corticosteroid-free treatment regimens.

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.

Galectin-9 in autoimmune hepatitis: Correlation between serum levels of galectin-9 and M2BPGi in patients with autoimmune hepatitis

Autoimmune hepatitis (AIH) is a disorder of unknown etiology in which immune-mediated liver damage progresses to cirrhosis or hepatocellular carcinoma (HCC). The mainstay therapy for AIH is steroids and other immunosuppressive treatments. Currently, there are no validated markers for monitoring immune-mediated hepatic inflammation. Galectin-9 has recently been identified as a potential biomarker in patients with chronic liver disease. The objective of this study was to determine whether Galectin-9 and other serum proteins are associated with active disease in AIH patients.We enrolled 77 Japanese patients with well-documented AIH who were identified from the National Hospital Organization-AIH-liver-network database, as well as 32 patients with chronic hepatitis C (CHC), 27 patients with SLE, and 17 healthy control subjects. Serum levels of galectin-9, and markers of liver injury were measured and compared between groups.Serum levels of galectin-9 were significantly higher in AIH patients than in CHC patients (13.8 ± 4.9 ng/mL vs 8.9 ± 3.0 ng/mL, P < .001) or healthy controls (13.8 ± 4.9 ng/mL vs 5.0 ± 1.3 ng/mL, P < .001). In AIH group, serum galectin-9 levels weakly correlated with alanine aminotransferase levels or total bilirubin (TB) and strongly correlated with C-X-C motif chemokine 10 (CXCL10) and Mac-2 binding protein glycosylation isomer (M2BPGi) levels, but did not correlate with the histological grade of liver fibrosis. Steroid treatment of AIH patients significantly reduced serum galectin-9 levels (14.1 ± 4.9 ng/mL vs 8.3 ± 3.8 ng/mL, P < .001). SLE patients exhibited higher galectin-9 levels, whereas the galectin-9 levels did not correlate with liver function tests such as alanine aminotransferase levels.Serum galectin-9 correlated with disease status in AIH patients and could thus be useful biomarkers to detect hepatic autoimmunity. Because circulating galectin-9 reflects autoimmune-mediated inflammation, it may have additional utility as a biomarker for other autoimmune disorders.