Soluble adhesion molecules in immune mediated liver disease

Inflammatory and cardiovascular diseases biomarkers in chronic hepatitis C virus infection: A review

Hepatitis C virus (HCV) infects 180 million people worldwide and over 4 million people in the United States. HCV infection is a major cause of chronic liver disease and is recognized as a risk factor for clinical cardiovascular disease (CVD). Many studies have shown increased prevalence of cardiac and inflammatory biomarkers in patients with chronic HCV infection (CHC), and though these markers may be used to risk stratify people for cardiac disease in the general population their role in the HCV population is unknown. Patients with CHC have elevated cardiac and inflammatory biomarkers compared to noninfected controls which may play a role in CVD risk stratification. We undertook a systematic review of inflammatory and cardiac biomarkers in people with HCV infection with a focus on the effect of CHC on serum levels of these markers and their utility as predictors of CVD in this population. Medline, EMBASE, and Cochrane databases were searched for relevant articles until June 2019. A total of 2430 results were reviewed with 115 studies included. Our review revealed that HCV infection significantly alters serum levels of markers of inflammation, endothelial function, and cardiac dysfunction prior to HCV treatment, and some of which may change in response to HCV therapy. Current risk stratification tools for development of CVD in the general population may not account for the increased inflammatory markers that appear to be elevated among HCV‐infected patients contributing to increased CVD risk.

Nonresponse to interferon monotherapy in HCV-related chronic hepatitis: results of retreatment and prognostic factors

At present two of the most relevant problems of the therapy of HCV-related chronic active hepatitis are the retreatment of nonresponders to interferon-alpha (IFN-alpha) and the definition of a prognostic index of response. We treated 44 patients who previously were nonresponders to IFN-alpha alone with IFN-alpha plus ribavirin for 12 months. Among the tests performed, we included the serum level of soluble intercellular adhesion molecule-1 (sICAM-1) at the beginning of the trial and at 3 months thereafter. We obtained 56.81% end of treatment responses and 47.72% sustained responses. A decrease of at least 10% of the sICAM-1 serum level during the first 3 months of treatment strongly correlated to the results of therapy while the usual important prognostic factors (HCV genotype and viral load) did not show this relation.

Serum intercellular adhesion molecule-I in children with chronic liver disease: relationship to disease activity

Intercellular adhesion molecule-I (ICAM-I) is a member of the immunoglobulin supergene family. It is expressed on the surface membrane of cells of multiple lineages at sites of inflammation. A soluble form of ICAM (sICAM-I) comprising the five extracellular Ig-like domains of ICAM-I has been detected in human serum and has been found to be increased in a variety of acute and chronic liver disorders. However, little is known about sICAM-I levels in children with chronic liver disease. Therefore, we measured sICAM-I in 23 children with chronic hepatitis, 14 children with cirrhosis, and 10 age- and sex-matched normal children by commercially available ELISA. We also correlated the sICAM-I levels with the histological activity index (HAI) score as determined from liver biopsies. Patients with chronic hepatitis had higher sICAM-I levels compared to controls (723 +/- 272 ng/ml vs 282 +/- 43 ng/ml, mean +/- SD; P < 0.05). sICAM-I levels were also higher in patients with cirrhosis compared to controls (630 +/- 218 ng, mean +/- SD; P < 0.05). However, there was no significant difference between sICAM levels in patients with chronic hepatitis and cirrhosis. A significant correlation was found between the ICAM-I level and the histological activity index score in patients with chronic hepatitis (r = 0.58; P < 0.001) and in patients with cirrhosis (r = 0.7; P < 0.001). We also found that by using the cutoff level of 346 ng/ml, sICAM-I can be used as a screening test with high specificity (100%) and sensitivity (94%) to differentiate children with chronic liver disease from normal children. We conclude that sICAM is increased in children with chronic hepatitis and cirrhosis compared to controls. The degree of elevation correlates with the HAI score. sICAM may be used as a marker of the disease activity and may provide diagnostic and prognostic information in children with chronic liver disease. However, this needs to be further studied.

sICAM-1, sCD95 and sCD95L levels in chronic liver diseases of different etiology

The release of soluble circulating molecules represents a prominent feature during the course of immune-mediated clinical conditions. To further assess the relationship between serum concentrations of adhesion or apoptotic-related soluble structures and liver diseases, we evaluated the levels of intercellular adhesion molecule-1 (sICAM-1), Fas receptor (CD95) and Fas ligand (sCD95L) in a group of patients affected by Hepatitis C Virus (HCV)-induced chronic hepatitis (CH-C), HCV-positive liver cirrhosis with superimposed hepatocellular carcinoma (HCC), autoimmune hepatitis (AIH), primary biliary cirrhosis (PBC) and alcoholic liver cirrhosis (ALC). Results show that sICAM-1 values were in all instances significantly elevated when compared to those seen in healthy donors. Similar findings were noted in subjects with liver diseases in terms of sCD95 concentrations, even if to a different degree of statistical significance. Finally, sCD95L amounts were augmented in AIH, PBC, ALC and CH-C in comparison to controls, while in the HCC counterpart sCD95L levels fell within normal range. All together, these findings emphasize the occurrence of circulating soluble molecules in patients with various chronic liver diseases, likely reflecting the involvement of several pathogenetic mechanisms.

Inhibition of macrophages with gadolinium chloride alters intercellular adhesion molecule-1 expression in the liver during acute endotoxemia in rats

Cell adhesion molecules are important for localized accumulation of phagocytes at sites of tissue damage. In the present studies, we analyzed the effects of blocking hepatic macrophages on expression of beta2 integrins and intercellular adhesion molecule-1 (ICAM-1) adhesion molecules on liver cells during acute endotoxemia. Flow cytometric analysis revealed distinct subpopulations of macrophages from control animals that varied on the basis of their size and density. In contrast, hepatocytes and endothelial cells were relatively homogeneous. Treatment of rats with endotoxin (5 mg/kg, intravenously) resulted in a time-dependent increase in the percentage of small, dense macrophages and a progressive loss of larger, less-dense cells. In contrast, no major effects were observed on the physical properties of hepatocytes or endothelial cells. ICAM-1 was found to be constitutively expressed on endothelial cells and hepatocytes, as well as on macrophages. Induction of acute endotoxemia resulted in a time-dependent increase in ICAM-1 expression on hepatocytes, which was observed within 3 hours and reached a maximum after 24 hours. An increase in ICAM-1 expression was also observed on endothelial cells and on macrophages at 3 hours, followed by a decrease at 24 to 48 hours. Macrophages and endothelial cells also constitutively expressed beta2 integrins. Induction of acute endotoxemia had no effect on beta2 integrin expression by these cells. Pretreatment of rats with gadolinium chloride (GdCl3), a macrophage inhibitor known to block endotoxin-induced liver injury, abrogated the effects of endotoxin on ICAM-1 expression by hepatocytes and macrophages. In contrast, ICAM-1 expression on endothelial cells increased. Interestingly, treatment of rats with GdCl3 alone resulted in a marked increase in expression of ICAM-1 on endothelial cells and hepatocytes, and of beta2 integrins on macrophages and endothelial cells. Taken together, these data suggest that ICAM-1 is involved in mediating macrophage adherence and accumulation in the liver during endotoxemia. Furthermore, macrophages appear to regulate expression of this cell adhesion molecule on parenchymal cells.

Circulating Form of Human Vascular Adhesion Protein-1 (VAP-1): Increased Serum Levels in Inflammatory Liver Diseases

Vascular adhesion protein-1 (VAP-1) is a dimeric 170-kDa endothelial transmembrane molecule that under normal conditions is most strongly expressed on the high endothelial venules of peripheral lymph nodes and on hepatic endothelia. It is a glycoprotein that mediates tissue-selective lymphocyte adhesion in a sialic acid-dependent manner. In this study, we report the detection of a soluble form of VAP-1 in circulation. We developed a quantitative sandwich ELISA using novel anti-VAP-1 mAbs and used it to determine the levels of soluble VAP-1 (sVAP-1) in the serum of healthy individuals and in patients with inflammatory diseases. In healthy persons, circulating sVAP-1 concentrations were 49 to 138 ng/ml. Immunoblotting studies revealed that the apparent molecular mass of dimeric sVAP-1 is slightly (∼10 kDa) higher than that of transmembrane VAP-1 under nonreducing conditions. In contrast, the electrophoretic mobilities of monomeric sVAP-1 and transmembrane VAP-1 were similar after reduction and boiling. Adhesion assays showed that the circulating sVAP-1 modulates lymphocyte binding to endothelial cells. Inflammation can cause an elevation of serum sVAP-1 levels, because sVAP-1 concentrations in patients with certain liver diseases were two- to fourfold higher than those in normal individuals. In contrast, rheumatoid arthritis and inflammatory bowel diseases were not associated with elevated levels of sVAP-1. These findings indicate that there is a functionally active, soluble form of VAP-1 in circulation and suggest that the serum level of sVAP-1 might be a useful marker of disease activity in inflammatory liver diseases.

Serum intercellular adhesion molecule-1 in alcoholic liver disease and its relationship with histological disease severity

BACKGROUND

Infiltration of the liver by leukocytes is a histological feature of alcoholic liver disease. Intercellular adhesion molecule-1 (ICAM-1) mediates the migration of lymphocytes from the circulation to target sites of inflammation. It has been demonstrated in the liver of alcoholic liver disease subjects and as a circulating soluble form (sICAM-1). The origin of sICAM-1 and its relationship to disease severity is unknown, although it has been postulated that it may arise from activated T lymphocytes and is an inflammatory marker.

AIMS

The aim of the study was to determine the relationship of sICAM-1 to clinical and histological severity of alcoholic liver disease and to serum T-cell (soluble interleukin-2 receptor (sIL-2R), beta 2-microglobulin) and monocyte (neopterin) immune activation markers.

METHODS

Serum from 48 outpatients with biopsy proven alcoholic liver disease (steatosis = 9, cirrhosis = 28, hepatitis +/- cirrhosis = 11), 31 with primary biliary cirrhosis and 27 normals was assayed for sICAM-1, sIL-2R, beta 2-microglobulin, and neopterin.

RESULTS

sICAM-1 was significantly elevated, p = 0.0001, in alcoholic liver disease and primary biliary cirrhosis patients compared to normals. Circulating sIL-2R (p = 0.0001) and beta 2-microgloblin (p = 0.0034) were significantly elevated in alcoholic liver disease compared to controls. There was a highly significant correlation between levels of sICAM-1 and histological grade of disease, Rs = 0.80 (p = 0.0001), but no significant correlation with clinical correlates of disease severity or circulating immune activation markers.

CONCLUSIONS

sICAM-1 is elevated in alcoholic liver disease, is a marker of histological severity of disease and does not appear to originate from activated T lymphocytes. Measurements of sICAM-1 may be useful in assessing histological severity of alcoholic liver disease.

Increased intercellular adhesion molecule-1 serum concentration in cholestasis

BACKGROUND/AIMS

Increase of serum levels of the soluble intercellular adhesion molecules in patients with the cholestatic liver diseases primary biliary cirrhosis (PBC) and primary sclerosing cholangitis (PSC) are known and have been thought to indicate activation of the immune system and the grade of the inflammatory process. In hepatitis and cholestatic diseases, expression of adhesion molecules was found on the surface of bile duct epithelia and hepatocytes.

MATERIALS AND METHODS

Serum levels of sICAM-1 in patients with intrahepatic cholestasis in PBC (n = 42) and extrahepatic cholestasis (n = 18) due to choledocholithiasis were investigated. sICAM-1 levels and "classical" cholestasis parameters as alkaline phosphatase (ALP), gamma-glutamyl-transpeptidase (gamma-GTP) and bilirubin levels were compared. Furthermore, sICAM-1 concentrations and "classical" cholestasis parameters were analysed before and after therapy with ursodeoxycholic acid (UDCA). In addition, sICAM-1 was detected in serum and bile fluid of four patients with cholestasis due to choledocholithiasis. Soluble ICAM-1 levels in sera and, if accessible, in bile fluids were determined using a commercially available ELISA system. Statistics were done by Wilcoxon's signed rank exact test and Spearman's rank correlation test. Sensitivity and specificity of cholestasis parameters and sICAM-1 concentrations was analysed by receiver operating characteristic (ROC) curves.

RESULTS

Increased sICAM-1 serum concentrations in a similar range were found in patients with PBC (range 251-2620 micrograms/l; median 966 micrograms/l) as well as in patients with extrahepatic cholestasis (257-2961 micrograms/l; median 760 micrograms/l) compared to healthy controls (n = 12; 220-500 micrograms/l; median 318 micrograms/l). sICAM-1 levels correlated significantly to histological stage I to IV (p < 0.001), ALP (range 107-1877 U/l; median 545 U/l; r = 0.496, p = 0.0008), bilirubin (range 0.3-26 mg/dl; median 0.8 mg/dl; r = 0.52; p < 0.0004) and gamma-GTP levels (range 43-705 U/l; median 221 U/l; r = 0.36; p = 0.02) in PBC patients. In PBC patients a histological stage III or IV (n = 21) could be predicted with high sensitivity (95%) and specificity (85%) if sICAM-1 levels were above 840 micrograms/l. After treatment of PBC patients with UDCA, sICAM-1 levels decreased significantly with decline of other "classical" cholestasis parameters. Increased sICAM-1 levels (range 257-2961, median 745 micrograms/l) in extrahepatic cholestasis correlated also significantly with serum concentrations of bilirubin (r = 0.8; p < 0.01; range 0.3-19.7, median 1.6 mg/dl), gamma-GTP (r = 0.55; p = 0.03; range 33-1401, median 179 U/l) and ALP (r = 0.61; p = 0.1; range 110-1378, median 562 U/l). sICAM-1 was detectable in bile fluid (264-919 micrograms/l) of four patients with extrahepatic cholestasis and nose-biliary catheterisation.

CONCLUSIONS

sICAM-1 concentrations were found to discriminate between histological stage I/II and stage III/IV of PBC with higher sensitivity and specificity than "classical" cholestasis parameters. Increased serum concentrations for sICAM-1 in intra- and in extrahepatic cholestasis and detection of sICAM-1 in the bile may indicate that sICAM-1 is eliminated through the bile. In other words, not only increased synthesis but also decreased elimination may be responsible for increased sICAM-1 serum levels in patients with cholestatic liver diseases.

Serum and ascitic levels of soluble intercellular adhesion molecule-1 in patients with alcoholic liver cirrhosis: relation to biochemical markers of disease activity and alcohol intake

The overexpression of intercellular adhesion molecule-1 (ICAM-1) has been shown to be involved in the pathogenesis of various necroinflammatory diseases, including alcoholic hepatitis. Shedding of this molecule from cell surfaces results in a circulating form, soluble ICAM-1 (sICAM-1). In this work, the serum and ascitic concentrations of sICAM-1 were studied in relation to clinical and laboratory data in patients with alcoholic liver cirrhosis of different disease activities. Elevated circulating concentrations of this adhesion molecule were found in all cirrhotic patients, the highest in those with superimposed severe alcoholic hepatitis, and the levels in regularly drinking cirrhotics without severe alcoholic hepatitis were likewise significantly higher than in those who had stopped drinking. The serum sICAM-1 concentration was best related to the serum AST activity, and also exhibited significant correlations with the prothrombin activity, serum bilirubin, albumin, peripheral leukocyte count. Maddrey's discriminant function value, Child grading, and antecedent alcohol consumption. Multivariate regression analysis revealed that the serum AST and prothrombin activities were independent predictors of the circulating sICAM-1 concentration. The concentration of sICAM-1 in the uninfected ascitic fluid of cirrthotics was about seven times lower than that in the serum; the ratio of its ascitic and serum levels was lower than that of the ascitic and serum total protein concentrations. These data contradict a significant intraperitoneal production of the molecule. It is concluded that the serum sICAM-1 level may be useful as a marker for the current disease activity (the severity of underlying acute necroinflammatory reactions) in alcoholic liver cirrhosis.