Caspase-cleaved fragments of cytokeratin-18 as a marker of inflammatory activity in chronic hepatitis B virus infection

Preliminary study on the diagnostic value of LEAP-2 and CK18 in biopsy-proven MAFLD

Metabolic Dysfunction-Associated Fatty Liver Disease (MAFLD) has become the leading cause of chronic liver disease. Liver biopsy, as the diagnostic gold standard, is invasive and has sampling bias, making it particularly important to search for sensitive and specific biomarkers for diagnosis. Cytokeratin 18 (CK18) M30 and M65 are products of liver cell apoptosis and necrosis, respectively, and liver-expressed antimicrobial peptide 2 (LEAP-2) is a related indicator of glucose and lipid metabolism. Correlation studies have found that all three indicators positively correlate with the liver enzymes alanine aminotransferase (ALT) and aspartate aminotransferase (AST). Through comparison of diagnostic values, it was found that CK18 M65 can better distinguish between healthy individuals and MAFLD; LEAP-2 can effectively distinguish MAFLD from other liver diseases, especially ALD.

4210 Da and 1866 Da polypeptides as potential biomarkers of liver disease progression in hepatitis B virus patients

HBV infection is recognized as a serious global health problem, and hepatitis B virus infection is a complicated chronic disease leading to liver cirrhosis (LC) and hepatocellular carcinoma (HCC). New biochemical serum markers could be used to advance the diagnosis and prognosis of HBV-associated liver diseases during the progression of chronic hepatitis B into cirrhosis and HCC. We determined whether the 4210 Da and 1866 Da polypeptides are serum metabolite biomarkers of hepatopathy with hepatitis B virus. A total of 570 subjects were divided into five groups: healthy controls, those with natural clearance, and patients with CHB, LC, and HCC. The 1866 Da and 4210 Da polypeptides were measured by Clin-ToF II MALDI-TOF-MS. There were significant differences in 4210 Da and 1866 Da levels among the five groups (P < 0.001). For the differential diagnosis of CHB from normal liver, the areas under the receiver operating characteristic (ROC) curve of 4210 Da and 1866 Da and their combination via logistic regression were 0.961, 0.849 and 0.967. For the differential diagnosis of LC from CHB, the areas under the ROC curve were 0.695, 0.841 and 0.826. For the differential diagnosis of HCC from CHB, the areas under the ROC curve were 0.744, 0.710 and 0.761, respectively. For the differential diagnosis of HCC from LC, the areas under the ROC curve of 4210 Da and 1866 Da were 0.580 and 0.654. The positive rate of 1866 Da was 45.5% and 69.0% in AFP-negative HCC patients and that of 4210 Da was 60.6% 58.6% in AFP-negative HCC patients of the study HCC vs. CHB and HCC vs. LC. The 4210 Da and 1866 Da polypeptide levels were positively correlated with HBV DNA levels (P < 0.001, r = 0.269; P < 0.001, r = 0.285). The 4210 Da and 1866 Da polypeptides had good diagnostic value for the occurrence and progression of HBV-related chronic hepatitis, liver cirrhosis and hepatocellular carcinoma and could serve to accurately guide treatment management and predict clinical outcomes.

Efficacy and Safety of Emricasan in Liver Cirrhosis and/or Fibrosis

This study aimed to perform a meta-analysis to determine the efficacy and safety of emricasan. Nine databases were searched for clinical trials investigating the efficacy of emricasan treatment in patients with liver cirrhosis or fibrosis. A manual search was conducted to identify the missing trials. The quality of the included studies was assessed using the revised Cochrane risk of bias tool. Efficacy of emricasan treatment was defined as a positive change in apoptosis-related parameters from baseline to the last follow-up visit. Overall, emricasan treatment is more effective in patients with liver cirrhosis or fibrosis than placebo (standardized mean difference [SMD] [95% confidence intervals (CI)]=0.28 [0.14; 0.41]). No significant change in model for end-stage liver disease (MELD) score between the emricasan and placebo groups was noted (SMD [95% CI]=0.18 [-0.01; 0.36]; p=0.058). A 50 mg dose of emricasan had the highest efficacy rate compared to placebo (SMD [95% CI]=0.28 [0.06; 0.50]; p=0.012), followed by the 5 mg dosing regimen (SMD [95% CI]=0.28 [0.06; 0.50]; p=0.012). Treatment with emricasan resulted in significant reductions in ALT (mean difference (MD) [95% CI]=-5.89 [-10.59; -1.20]; p=0.014) and caspase3/7 levels (MD [95%CI]=-1215.93 [-1238.53; -1193.33]; p<0.001), respectively. No significant increase in the rate of overall adverse events was noted (OR [95% CI]=1.52 [0.97; 2.37]; p=0.069). Treatment with emricasan is more effective in improving liver function and apoptosis parameters compared to placebo, with a well-tolerated safety profile. However, due to the poor quality of the analyzed studies, the small number of trials and patients, and the short follow-up periods, more robust trials are still warranted.

Time-Course Changes of Serum Keratin Concentrations after Liver Transplantation: Contrasting Results of Keratin-18 and Keratin-19 Fragments

Objective

Under normal conditions, adult hepatocytes express only keratin-8 (K8) and keratin-18 (K18), whereas cholangiocytes also express K19. In this study, we delineate the pattern of normal time-course changes in serum K19 and K18 levels after liver transplantation. Patients and Methods. Serum levels of the K19 fragment CYFRA 21-1 and the K18 fragments tissue polypeptide specific antigen (TPS) and M30 (a neoepitope that is generated after caspase cleavage during apoptosis) were measured at baseline and at regular intervals (up to 6 months) after liver transplantation in 11 adult patients.

Results

There was a gradual decrease in serum K19 concentrations from baseline values after transplantation, following a time-course pattern similar to that of serum bilirubin. In contrast, serum concentrations of K18 fragments increased markedly shortly after transplantation and gradually decreased thereafter, following a time-course pattern similar to that of serum transaminases. The increase in TPS tended to occur earlier than that in M30, suggesting an initial predominance of hepatocyte necrosis followed by a predominance of apoptosis in the first days after transplantation. Five patients presented posttransplant complications (acute rejection in three cases and HCV recurrence in two cases). An early increase in serum K19 concentrations was observed in all cases. An increase in serum concentrations of K18 fragments (M30 and TPS) was observed in the two cases with HCV recurrence and was more variable in the three cases with acute rejection.

Conclusions

Serum concentrations of K19 and K18 fragments follow a dissimilar pattern of time-course changes after liver transplantation. The diagnostic value of variations in these normal patterns should be addressed in future studies.

Serum regucalcin is a useful indicator of liver injury severity in patients with hepatitis B virus-related liver diseases

Regucalcin is a soluble protein that is principally expressed in hepatocytes. Studies of regucalcin have mainly been conducted in animals due to a lack of commercially available kits. We aimed to develop an enzyme-linked immunosorbent assay (ELISA) to quantify serum regucalcin in patients with hepatitis B virus (HBV)-related disease. High-titer monoclonal antibodies and a polyclonal antibody to regucalcin were produced, a double-antibody sandwich ELISA method was established, and serum regucalcin was determined in 47 chronic hepatitis B (CHB) patients, 91 HBV-related acute-on-chronic liver failure (HBV-ACLF) patients, and 33 healthy controls. The ELISA demonstrated an appropriate linear range, and high levels of reproducibility, sensitivity, specificity, accuracy, and stability. The median serum regucalcin concentrations in HBV-ACLF and CHB patients were 5.46 and 3.76 ng/mL, respectively (P<0.01), which were much higher than in healthy controls (1.72 ng/mL, both P<0.01). For the differentiation of CHB patients and healthy controls, the area under curve (AUC) was 0.86 with a cut-off of 2.42 ng/mL, 85.7% sensitivity, and 78.8% specificity. In contrast, the AUC of alanine aminotransferase (ALT) was lower (AUC=0.80, P=0.01). To differentiate ACLF from CHB, the AUC was 0.72 with a cut-off of 4.26 ng/mL, 77.0% sensitivity, and 61.2% specificity while the AUC of ALT was 0.41 (P=0.07). Thus, we have developed an ELISA that is suitable for measuring serum regucalcin and have shown that serum regucalcin increased with the severity of liver injury due to HBV-related diseases, such that it appears to be more useful than ALT as a marker of liver injury.

Serum keratin-18 fragments as cell death biomarker in association with disease progression and prognosis in hepatitis B virus-related cirrhosis

Extensive hepatocyte death leads to hepatic inflammation and contributes to systemic inflammation in decompensated cirrhosis. We aimed to investigate the prognostic value of serum cell death markers in patients with hepatitis B virus (HBV)-related acute decompensation (AD) of cirrhosis with and without acute-on-chronic liver failure (ACLF). We studied two cohorts-cohort 1: 201 outpatients with stable chronic hepatitis B (49 cirrhosis); cohort 2: 232 inpatients with HBV-related cirrhosis admitted for AD. Cell death was determined with serum keratin-18 (K18) for total death and serum caspase-cleaved-K18 (cK18) for apoptosis. Survival analyses were performed using competing risk method. We found that serum K18 and cK18 were significantly (P < 0.001) higher in patients from cohort 2 than those from cohort 1. Among cohort 2, ACLF patients had significantly (P < 0.001) increased K18 and cK18 comparing to those without ACLF. Increased K18 and cK18 were mainly attributed to HBV flare and were associated with liver and coagulation failure. HBV-AD patients without ACLF who admitted with upper tertile of K18 or cK18 were at higher risk of developing ACLF during follow-up. Baseline serum K18 or cK18 was significantly associated with transplant-free 90-day survival independent of leucocytes, HBV DNA, bacterial infection, encephalopathy and severity scores. The combination of cell death biomarkers significantly improved the prognostic value of the currently established prognostic scores. The reduction of cell death level after standard treatment was associated with increased short-term survival. In conclusion, measurements of serum K18 or cK18 in HBV decompensated cirrhosis are a promising tool for predicting ACLF and risk stratification of short-term outcome.

Serum cytokeratin-18 and its relation to liver fibrosis and steatosis diagnosed by FibroScan and controlled attenuation parameter in nonalcoholic fatty liver disease and hepatitis C virus patients

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) has emerged as the most common cause of chronic liver disease worldwide. Multiple diagnostic noninvasive methods for NAFLD were studied (both serological and imaging), either single or combined. Attention has been focused on cytokeratin-18 (CK18) as a novel serological marker for the diagnosis of steatosis/fibrosis in NAFLD and hepatitis C virus (HCV) patients.

AIM

The aim of this study was to evaluate serum CK18 in NAFLD and HCV fibrosis/steatosis and also to correlate its performance with the diagnostic accuracy of transient elastography (TE) and controlled attenuation parameter (CAP) in the diagnosis of fibrosis/steatosis in these patients.

PATIENTS AND METHODS

Three equal groups of participants were enrolled (n=135): group I included patients with chronic HCV, group II included NAFLD patients, and group III included control participants. For all groups, TE/CAP and labs including serum CK18 were performed. Liver biopsy was performed for the NAFLD group.

RESULTS

Serum CK18 was significantly higher in the NAFLD group (19.01±3.49 ng/ml) versus the HCV group (8.95±1.06 ng/ml) and the control group (4.83±1.6 ng/ml) (P<0.001). The CK18 levels in biopsy stages (steatosis, ballooning, inflammation, and fibrosis) and FibroScan/CAP degrees showed that CK18 increased significantly with steatosis and fibrosis stages (biopsy or FibroScan/CAP), but did not reach significance with ballooning or inflammation grades. CK18 was significantly different in nonalcoholic steatohepatitis versus non-nonalcoholic steatohepatitis patients (P=0.041). The best CK18 cutoff to detect steatosis (S≥2) in NAFLD and HCV was 11.65 and 6.84 ng/ml, respectively with an overall sensitivity and specificity over 97%. The CK18 cutoff for significant fibrosis (F≥2) by FibroScan in the NAFLD/HCV groups was 9.115 ng/ml, with 62.5%/69.2% sensitivity/specificity (P=0.031). However, inflammation had a cutoff with a marginal P value (P=0.080), and a reliable cutoff for ballooning was not attained (P=0.386). There was a positive correlation between CK18 and fibrosis (by FibroScan) in the NAFLD and HCV groups (P<0.05). The correlation between CK18 and steatosis in CAP and the nonalcoholic fatty liver disease activity score was very good (P<0.001).

CONCLUSION

Serum CK18 is related strongly to the development/progression of NAFLD and HCV-related fibrosis/steatosis. TE was correlated highly with liver biopsy results. The combination of CK18 with other noninvasive modalities increases the diagnostic yield of these tests.

Emricasan Improves Liver Function in Patients With Cirrhosis and High Model for End-Stage Liver Disease Scores Compared With Placebo

BACKGROUND & AIMS

Caspase-mediated apoptosis and inflammation contribute to progression of liver disease. Emricasan is a pan-caspase inhibitor that reduced serum markers of apoptosis and liver inflammation in patients with hepatitis C and non-alcoholic steatohepatitis (NASH).

METHODS

We performed a multicenter study of 86 patients with cirrhosis (Child-Pugh class A or B; mean score, 6.9; 38% with alcohol-associated cirrhosis, 29% with HCV-associated cirrhosis, and 23% with NASH) and model for end-stage liver disease (MELD) scores of 11-18 (mean, 12.8). Patients were randomly assigned to groups given placebo (N = 42) or Emricasan (25 mg, N = 44), twice daily for 3 months; subjects then received open-label Emricasan (25 mg) twice-daily for 3 months. The primary endpoint was the change from baseline in serum levels of cleaved keratin 18 (CK-18) at month 3.

RESULTS

Seventy-four patients completed the 3-month study period (40 given Emricasan and 34 given placebo); 69 patients received open-label Emricasan for 3 months afterward. At the 3-month timepoint, Emricasan significantly reduced mean MELD (P = .003) and Child-Pugh (P = .003) scores in subjects with high MELD scores (15 or more), compared with placebo, with significant reductions in INR (95% CI, -0.2882 to -0.0866) and total bilirubin (95% CI, -1.5069 to -0.0823) vs placebo. There were no significant differences between Emricasan and placebo groups in mean MELD (P = .466) or Child-Pugh (P = .124) scores overall at 3 months compared to placebo. Of patients with high MELD scores, 6/9 given Emricasan (67%) had a reduction of 2 points or more at month 3, compared with 2/10 given placebo (20%). Serum levels of full-length CK-18 (P = .02) and caspase 3/7 (P < .001), but not cleaved CK-18 (P = .092), decreased significantly at 3 months in the Emricasan vs placebo group. Emricasan was well tolerated, and adverse events were balanced between groups. Emricasan's effects were generally maintained or increased after 6 months of treatment.

CONCLUSIONS

In a randomized trial of patients with cirrhosis, we found 3 months treatment with Emricasan to improve liver function, compared with placebo, reducing MELD and Child-Pugh scores, INR, and total bilirubin in patients with MELD scores ≥15. ClinicalTrials.gov no: NCT02230670.

Expression of MMP-9 in different degrees of chronic hepatitis B and its correlation with inflammation

Expression of matrix metalloproteinase-9 (MMP-9) in different degrees of chronic hepatitis B (CHB) and the correlation of MMP-9 with inflammation was investigated. A total of 96 CHB patients (observation group) admitted and treated in Dongying People's Hospital from December 2016 to November 2017 were selected, and they were compared with 60 healthy individuals (control group) selected in the physical examination center during the same time period. Enzyme-linked immunosorbent assay (ELISA) was used to detect the expression of MMP-9, tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6), MMP-9 expression in different inflammation grades and fibrosis stages, and the relationship between MMP-9 and inflammation was analyzed. The levels of MMP-9, TNF-α and IL-6 in serum in the observation group were obviously higher than those in the control group (P<0.05). The rank sum test indicated that there were statistically significant differences in the expression levels of MMP-9 among the inflammation grades G0, G1, G2, G3 and G4 (P<0.05). The expression levels of MMP-9 in fibrosis stages S0, S1, S2, S3 and S4 were detected via the rank sum test, and it suggested that the differences among the 5 stages were statistically significant (P<0.05). Pearsons correlation analysis showed that the MMP-9 expression level was positively correlated with TNF-α and IL-6 (P<0.05). In conclusion, the MMP-9 level is elevated remarkably in patients with varying degrees of CHB, it may play an important role in the pathological progress of liver, and it has a close correlation with inflammation, which can provide a theoretical basis for clinical treatment.

Serum levels of caspase-cleaved cytokeratin 18 (CK18-Asp396) predict severity of liver disease in chronic hepatitis B

Background and aim

Caspase-cleaved cytokeratin 18 (CK18-Asp396) is a potential clinically useful biomarker in liver disease as it is released from hepatocytes during apoptosis. In this study, we investigated serum CK18-Asp396 levels in chronic hepatitis B (CHB).

Patients and methods

Overall, 163 patients with CHB were included. Serum CK18-Asp396 levels were determined by enzyme-linked immunosorbent assay (ELISA), and results were related to steatosis grade, histological activity index, inflammation score, and METAVIR fibrosis grade as well as to viral load, serum levels of liver enzymes, and albumin. Receiver operating characteristic analysis was used to evaluate the diagnostic performance of serum CK18-Asp396 levels for assessing disease activity.

Results

A higher level of serum CK 18 concentrations was found in patients with significant inflammation vs no significant inflammation (378.5 [interquartile range {IQR}: 173.2–629.6] vs 137.3 [87.5–197.7], P < 0.05; approximately threefold increase) and in patients with significant fibrosis vs no significant fibrosis (177.8 [IQR: 120.8–519.1] vs 142.7 [IQR: 88.8–214.4], P < 0.05; 1.25-fold increase). There was no differential CK 18 level by degree of steatosis. CK 18 was an independent predictor of significant inflammation with an 82% specificity and a 94% negative predictive value. We found the strongest correlation of CK 18 with alanine aminotransferase and aspartate aminotransferase (both r = 0.52; P < 0.001), but less with albumin (r = −0.24; P < 0.05) and viral load (log) (r = 0.19; P < 0.05).

Conclusion

CHB appears to be accompanied by continuous high levels of hepatocyte apoptosis as judged from serum CK 18, suggesting that elimination of the infected compartment constitutes a defensive strategy against disease. Accordingly, CK 18 works as an independent predictor of significant inflammation with a high specificity.

Serum Cytokeratin 18 M30 Levels in Chronic Hepatitis B Reflect Both Phase and Histological Activities of Disease

Chronic hepatitis B has highly a dynamic course with significant fluctuations of HBV-DNA and ALT impeding assessment of disease activity. New biomarkers of inflammatory versus noninflammatory stages of HBV infection are urgently needed. Cytokeratin 18 epitope M30 (M30 CK-18) is a sensitive marker of cell death. We aimed to investigate an association between serum M30 CK-18 and histological activity and phase of HBV infection. 150 Caucasian patients with HBV-infection were included in the study. Serum M30 CK-18 levels reflected phase of disease, being significantly higher in both HBeAg(+) and HBeAg(−) hepatitis B in comparison to HBsAg(+) carrier groups. The highest serum M30 CK-18 levels were observed in subjects with the most advanced stages of HBV. Moreover, its serum concentrations correlated with both inflammatory activity and fibrosis advancement (ANOVA P < 0.001). Importantly, serum M30 CK-18 levels were able to discriminate patients with mild versus moderate-advanced fibrosis (AUC: 0.86) and mild versus active liver inflammation (AUC: 0.79). M30 CK-18 serum concentration has good sensitivity and specificity in discriminating mild versus moderate/severe fibrosis and inflammation even in patients with normal ALT activity. This study suggests M30 CK-18 as a potential noninvasive marker of disease activity and also a marker of phase of persistent HBV infection.

Relationship between liver injury and serum cytokeratin 18 levels in asymptomatic hepatitis B virus carriers and in patients with chronic hepatitis B infection

BACKGROUND AND STUDY AIMS

Apoptosis represents a well-known mechanism of cell death involved in most chronic liver injuries. Our aim was to investigate the serum fragment level of cytokeratin 18 (CK18), M30, in asymptomatic hepatitis B virus (HBV) carriers and patients with chronic hepatitis B (CHB) and to evaluate the relationship between serum M30 levels and the severity of hepatic injury.

PATIENTS AND METHODS

Asymptomatic HBV carriers (n=169), patients with CHB (n=100), and healthy control subjects (n=43) were enrolled in the study. Serum CK18 (M30) levels were analysed in all subjects. Liver biopsy for histopathological assessment was performed in asymptomatic HBV carriers and in patients with CHB infection.

RESULTS

Serum CK18 (M30) levels were significantly higher in asymptomatic HBV carriers (198.77±77.62U/L) than in healthy control subjects (146.92±40.18U/L). Patients with CHB (283.02±147.45U/L) had significantly higher CK18 (M30) levels than asymptomatic HBV carriers (p=0.001). The diagnostic efficacy of CK18 (M30) levels in distinguishing patients with HBeAg-negative CHB from asymptomatic HBV carriers was found to be moderate (c-statistics: 0.695), and the diagnostic cut-off value of CK18 (M30) was 262U/L (specificity: 85%, sensitivity: 48%, positive likelihood ratio: 3.35, and negative likelihood ratio: 0.60). There was a positive correlation between serum CK18 (M30) levels and histological activity index scores in asymptomatic HBV carriers and patients with CHB.

CONCLUSIONS

Serum CK18 (M30) levels may be a valuable indicator in distinguishing asymptomatic HBV carriers from patients with HBeAg-negative CHB when considered together with ALT and HBV-DNA levels.

Cell death biomarker M65 is a useful indicator of liver inflammation and fibrosis in chronic hepatitis B: A cross-sectional study of diagnostic accuracy

Cell death markers, M65 and M30, have been suggested to be sensitive markers of liver inflammation and fibrosis in nonalcoholic fatty liver disease and chronic hepatitis C. Our aim was to investigate whether these markers were useful in diagnosing liver inflammation and fibrosis in chronic hepatitis B (CHB).We examined 186 patients with CHB; 18 sex- and age-matched healthy subjects were controls. The blood samples were collected from CHB patients within 1 week before or after liver biopsy. According to METAVIR score system, liver inflammation was graded from A0 to A3, and fibrosis from F0 to F4.Serum M65 and M30 levels were in parallel with the grades of liver inflammation. M65, not M30, increased significantly in patients with severe inflammation and normal alanine aminotransferase. M65 is one of the independent predictors of severe liver inflammation (≥A2). The levels of M65 and M30 levels significantly increased in parallel with the degree of inflammation in F1 patients, whereas they showed no statistical difference between different stages of fibrosis in A1 patients.Serum M65 is a useful indicator of liver inflammation in CHB patients. Serum M65, not M30, is valuable in the grading of liver fibrosis.

Serum hepatocyte apoptosis biomarker predicts the presence of significant histological lesion in chronic hepatitis B virus infection

BACKGROUND

Hepatocyte death, either apoptosis or necrosis, is closely associated with hepatic inflammation and fibrosis.

AIMS

To investigate the potential values of hepatocytes death biomarker, M30 (apoptosis) and M65 (total death) in predicting histological lesions in chronic hepatitis B virus (HBV) infection.

METHODS

Total 201 treatment-naïve patients were prospectively recruited. Liver biopsies were performed prior to antiviral treatments for treatments starting evaluation. Sera were collected on the day of liver biopsy for biomarker measurements. Sera from 200 age-matched healthy volunteers served as healthy controls (HCs).

RESULTS

Significant histological lesions (SHL, i.e. significant inflammation and/or significant fibrosis) were confirmed in 150 (74.63%) patients. There were significantly higher serum M30 and M65 in patients with SHL than those without SHL (p<0.001) or than HCs (p<0.001). Serum M30, but not M65, independently predicted SHL [odds ratio:3.4 (95% CI, 1.8-6.2) per increase of 50U/L, p<0.001] after adjusting other potential confounding factors. A novel model based on M30 provided good diagnostic performance in predicting SHL [AUC, 0.87 (0.81-0.92)]. Cut-off value of >0 to confirm or ≤-0.5 to exclude SHL has ∼12% misclassification rate.

CONCLUSION

Hepatocyte apoptosis biomarker, M30 is a promising non-invasive alternative to liver biopsy in chronic HBV infection upon treatment evaluation.

Keratins: Biomarkers and modulators of apoptotic and necrotic cell death in the liver

Keratins, formerly known as cytokeratins, are the major epithelial-specific subgroup of intermediate filament proteins. Adult hepatocytes express keratin polypeptides 8 and 18 (K8/K18), whereas cholangiocytes express K8/K18 and keratins 7 and 19 (K7/K19). Keratins function primarily to protect hepatocytes from apoptosis and necrosis, which was revealed using several genetic mouse models. This cytoprotective function was further clarified by the identification of natural human keratin variants that are normally silent, but become pathogenic by predisposing their carriers to apoptosis during acute or chronic liver injury mediated by toxins, virus infection, or metabolic stress. During apoptosis, caspases cleave K18 and K19 at conserved aspartates (human K18/K19: (235) Val-Glu-Val-Asp(↓) ) and K18 at a unique aspartate (human K18: (394) Asp-Ala-Leu-Asp(↓) ), with the latter exposed epitope becoming recognized by the M30 antibody in blood and tissues. Additional K18-containing protein backbone epitopes are detected using the M6 and M5 (termed M65) antibodies. Intact K18 and its associated fragments, which are released into blood during apoptosis and necrosis in various diseases, have been analyzed by enzyme-linked immunosorbent assay using the M30/M65 antibodies or their signal ratios. Furthermore, M30/M65 levels have been used as diagnostic and prognostic biomarkers in acute and chronic liver diseases, including nonalcoholic steatohepatitis and acute liver failure. Other keratin biomarkers include K8/K18/K19-related tissue polypeptide antigen, K18-related tissue polypeptide-specific antigen, and K19-related CYFRA-21-1, which have been evaluated mostly in patients with epithelial tumors.

CONCLUSION

Keratins and their fragments are released into blood during liver and other epithelial tissue injury. The epithelial specificity of K18/K19, epitope unmasking upon caspase digestion, keratin abundance, and relative keratin stability render them useful biomarkers for hepatocyte and cholangiocyte apoptosis and necrosis. However, the precise biochemical nature and release mechanism of circulating keratins remain unknown. (Hepatology 2016;64:966-976).

Cytokeratin 18-Aspartate396 apoptotic fragment for fibrosis detection in patients with non-alcoholic fatty liver disease and chronic viral hepatitis

BACKGROUND

The combination of non-invasive markers for the detection of fibrosis in patients with chronic liver diseases is still a matter of debate.

AIMS

To test the performance of cytokeratin18-Aspartate396 alone or in combination with transient elastography as a marker of fibrosis, compared to liver biopsy as gold standard.

METHODS

In 259 prospectively enrolled patients with chronic liver diseases, clinical, biochemical, and histological features were assessed. Serum cytokeratin18-Aspartate396 and Fibroscan were performed within 6 months prior to liver biopsy.

RESULTS

Cytokeratin18-Aspartate396 levels predicted both significant and advanced fibrosis in non-alcoholic fatty liver disease group, correctly identifying 83.7% and 80.8% of cases, respectively. Liver stiffness performed best in predicting severe fibrosis in patients with chronic viral infection, correctly identifying 78.7% of chronic hepatitis B and 88.6% of chronic hepatitis C subjects. The combination of cytokeratin18-Aspartate396 and liver stiffness improved their diagnostic performance for the detection of significant and advanced fibrosis in non-alcoholic fatty liver disease group, only (sensitivity=78.3%, specificity=90.7%; sensitivity=91.7%, specificity=71.6%, respectively).

CONCLUSION

Cytokeratin18-Aspartate396 and liver stiffness can improve the non-invasive prediction of significant and advanced fibrosis in patients with non-alcoholic fatty liver disease, while in hepatitis B and C virus infected patients their combined use had no advantage over the diagnostic accuracy of transient elastography alone.

Serum levels of ET-1, M30, and angiopoietins-1 and -2 in HELLP syndrome and preeclampsia compared to controls

PURPOSE

We aimed to compare the serum levels of ET-1, M30, and Angs-1 and -2 in patients with preeclampsia or HELLP syndrome, and normal controls.

METHODS

In this cross-sectional study of 74 pregnant women, serum levels of ET-1, M30, and Angs-1 and -2 were measured in preeclamptic patients with or without HELLP syndrome. 74 pregnant women; 37 had healthy pregnancies, 25 had preeclampsia (PE), and 12 had HELLP syndrome.

RESULTS

The age, body mass index, gravidity, and parity of patients with normal pregnancy, PE, and HELLP syndrome were comparable (p > 0.05). In HELLP syndrome, compared to healthy or preeclamptic pregnancies, platelet count was lower (p < 0.05) and the values of hepatic function tests were higher (p < 0.05). In HELLP syndrome, ET-1, M30, and Ang-2 were higher compared to healthy or preeclamptic pregnancies (p < 0.05); however, they increased in preeclamptic pregnancies compared to healthy pregnancies though not significant (p > 0.05). In PE or HELLP syndrome, Ang-1 was higher compared to a healthy pregnancy (p < 0.05); however, in HELLP syndrome, it was also higher than in PE though not significant (p > 0.05). We found no significant correlation among these biomarkers and hematological and biochemical parameters (p > 0.05).

CONCLUSION

For the diagnosis of HELLP syndrome, increased levels of ET-1, M30, and Angs-1 and -2 appear as promising biomarkers after determination of their standardized threshold levels after further studies. As an apoptosis-related biomarker, serum M30 level has a merit to be the most promising test for prediction or differential diagnosis of HELLP syndrome in PE patients.