Serum laminin P1 in chronic viral hepatitis: correlations with liver histological activity and diagnostic value

Applying Non-Invasive Fibrosis Measurements in NAFLD/NASH: Progress to Date

Nonalcoholic fatty liver disease (NAFLD) has now become a worldwide health issue due to the obesity epidemic, affecting approximately 90% of the obese population and 15-40% of the general population. It is the most common form of chronic liver disease in the United States. NAFLD constitutes a spectrum of diseases ranging in severity from mild, such as fatty liver, progressing into nonalcoholic steatohepatitis (NASH), then fibrosis, and ending with cirrhosis. NASH and increasing fibrosis stage are associated with increased morbidity and mortality; the fibrosis stage is therefore a critical element of risk stratification needed to determine therapeutic approach and also the response to treatment. Liver biopsy is considered the 'gold standard' in the diagnosis of NAFLD. However, it is not practical for widespread clinical use because it is invasive, costly, and associated with complications including occasional death. These limitations have driven the development of noninvasive tests that can accurately predict the fibrosis stage in those with NAFLD. In this review, we provide a concise overview of different non-invasive measurements used for NAFLD/NASH.

Diagnostic performance of collagen IV and laminin for the prediction of fibrosis and cirrhosis in chronic hepatitis C patients: a multicenter study

BACKGROUND/AIM

To date, liver biopsy has been the gold standard used for the assessment of liver fibrosis in patients with chronic hepatitis C. Our aim was to evaluate the diagnostic performance of a panel of simple blood markers of liver fibrosis and the development a novel score to replace liver biopsy.

PATIENTS AND METHODS

Liver biochemical profile including transaminases, bilirubin, alkaline phosphatase, and albumin, in addition to platelet count, was evaluated using standard methods in 305 chronic hepatitis C patients. Serum type IV collagen and laminin were assayed using the ELISA technique. Liver biopsies were performed. Statistical analyses were carried out by logistic regression and receiver operating characteristic curves to assess and compare the diagnostic accuracy of blood markers. A stepwise combination algorithm was developed and validated in 317 additional patients.

RESULTS

The Fibrosis Discriminant Score (FDS) was developed combining collagen, laminin, aspartate aminotransferase/platelet ratio index, and albumin. FDS produced an area under receiver operating characteristic curve of 0.831 for significant fibrosis, 0.791 for advanced fibrosis, and 0.881 for cirrhosis. The FDS was correctly classified in 82% of patients with significant fibrosis with 79% sensitivity and 88% specificity at cut-off 0.66 or more. Similar results were obtained in a validation study in which, of 317 patients, liver biopsy could have been avoided in 81%.

CONCLUSION

A simple fibrosis index can be useful to select hepatitis C virus-infected patients with a very low risk of significant fibrosis in whom the protocol of liver biopsies may be avoided.

Interferon α-2a reduces carbon tetrachloride-induced hepatic fibrosis in rats

AIM: To observe the effect of IFNα-2a on liver fibrosis induced with carbon tetrachloride (CCl₄) in rats.

METHODS: Fifty female Sprague-Dawley rats were equally and randomly into five groups: groups A, B, C, D and E. Liver fibrosis was induced in rats of groups B, C and D with CCl₄. Group A was treated with normal saline, while groups C, D and E were treated with 60 000, 120 000 and 60 000 U/kg IFNα-2a, respectively. At week 8, blood and liver tissue samples were collected to measure liver function (ALT, AST, TBIL, TP), evaluate liver fibrosis (HA, LN, PCIII) and pathological changes (HE staining, masson staining and reticular fiber staining).

RESULTS: Hepatic fibrosis was successfully induced by CCl₄ injection, and significant fibrosis around the portal area and formation of spiky fibers and fibrous septa were observed. Serum levels of ALT, AST, TBiL, HA and LN levels were significantly higher in groups B, C and D than in group A (F = 14.8, 4.4, 7.8, 51.3, 68.9; all P < 0.05). Serum levels of ALT, AST and TBiL were significantly lower in groups C and D than in group B, and in group D than in group C.

CONCLUSION: IFNα-2a reduces CCl₄-induced liver fibrosis in a dose-dependent manner in rats.

Serum laminin assayed by Slot-Blot-ELISA in patients with combined viral hepatitis C and schistosomiasis

OBJECTIVES

Hepatic schistosomiasis and chronic hepatitis C virus (HCV) are the most prevalent agents causing hepatic fibrosis in humans. Laminin (LA) has been related to liver fibrosis and subsequent development of portal hypertension in chronic liver disease. There are no available data describing the pattern of laminin in combined HCV and schistosoma-infected patients, thus the rationale of this study was to assess the serum LA as an index of liver fibrosis in patients with schistosomiasis and/or chronic viral hepatitis C and to evaluate a developed Slot-Blot Enzyme-Linked Immunosorbant Assay (Slot-Blot-ELISA) as a method of estimation.

DESIGNS AND METHODS

This study included four groups: group I included 34 patients with schistosomiasis, group II included 58 patients infected with HCV, group III included 68 patients with combined chronic viral hepatitis C and schistosomiasis and group IV included 50 healthy individuals who served as a control group. Serum LA was measured in the different groups quantitatively by ELISA and semi-quantitatively by Slot-Blot-ELISA.

RESULTS

Significantly higher serum LA concentrations measured by ELISA were found in patients with combined chronic viral hepatitis C and schistosomiasis than in patients with either chronic HCV (P = 0.005) or schistosomiasis (P < 0.001) alone. Serum LA was significantly higher in the patient groups than the control group (P < 0.001). Serum LA concentration was positively correlated with fibrosis grading scores. Semi-quantitative results of serum LA using the developed SB-ELISA were found to have approximately the same power of ELISA results in different groups. The overall sensitivity, specificity, positive predictive value, negative predictive value and efficiency of ELISA for estimation of serum LA were 85.6%, 84.0%, 94.5%, 64.6% and 90%, respectively and for SB-ELISA were 87.5%, 82.0%, 94%, 67.2% and 88%, respectively.

CONCLUSIONS

Serum LA was significantly increased in patients coinfected with HCV and Schistosoma mansoni. The newly developed Slot-Blot-ELISA is a simple, rapid and highly sensitive assay for detection of LA in hepatic fibrosis. Moreover, all steps were performed at room temperature without the need to use expensive equipment, and this may enhance the application of this assay in screening programs. Further study is warranted for confirmation of SB-ELISA reproducibility in a large population.

A chemotactic peptide from laminin alpha 5 functions as a regulator of inflammatory immune responses via TNF alpha-mediated signaling

Tissue injury triggers inflammatory responses that may result in release of degradation products or exposure of cryptic domains of extracellular matrix components. Previously, we have shown that a cryptic peptide (AQARSAASKVKVSMKF) in the alpha-chain of laminin-10 (alpha5beta1gamma1), a prominent basement membrane component, is chemotactic for both neutrophils (PMNs) and macrophages (Mphis) and induces matrix metalloproteinase-9 (MMP-9) production. To determine whether AQARSAASKVKVSMKF has additional effects on inflammatory cells, we performed microarray analysis of RNA from RAW264.7 Mphis stimulated with AQARSAASKVKVSMKF. Several cytokines and cytokine receptors were increased >3-fold in response to the laminin alpha5 peptide. Among these were TNF-alpha and one of its receptors, the p75 TNFR (TNFR-II), increasing 3.5- and 5.7-fold, respectively. However, the peptide had no effect on p55 TNFR (TNFR-I) expression. Corroborating the microarray data, the protein levels of TNF-alpha and TNFR-II were increased following stimulation of RAW264.7 cells with AQARSAASKVKVSMKF. In addition, we determined that the production of TNF-alpha and TNFR-II in response to AQARSAASKVKVSMKF preceded the production of MMP-9. Furthermore, using primary Mphis from mice deficient in TNFR-I, TNFR-II, or both TNF-alpha receptors (TNFRs), we determined that AQARSAASKVKVSMKF induces MMP-9 expression by Mphis through a pathway triggered by TNFR-II. However, TNF-alpha signaling is not required for AQARSAASKVKVSMKF-induced PMN release of MMP-9 or PMN emigration. These data suggest that interactions of inflammatory cells with basement membrane components may orchestrate immune responses by inducing expression of cytokines, recruitment of inflammatory cells, and release of proteinases.

Serum concentrations of laminin-P1 in thrombotic microangiopathy: usefulness as an index of activity and prognostic value

Laminin is the main noncollagenous constituent of the basement membrane, and its serum levels could reflect the metabolic changes that occur in the basement membrane. Severe endothelial injury with thickening of basement membrane is a characteristic feature of thrombotic microangiopathy (TMA). With this background, the aim of the study was to investigate in a prospective way (1) the relationship among serum Lam-P1, the extent of renal histopathologic lesions, and the biochemical parameters commonly used as markers of TMA activity, and (2) the usefulness of serum Lam-P1 concentrations as a renal outcome prognostic index. To this end, 18 consecutive patients with active biopsy-proven TMA with renal involvement were studied. One hundred and twenty-one healthy control subjects, 20 patients with systemic scleroderma without renal involvement, and 35 patients with systemic lupus erythematosus (20 without nephropathy and 15 with diffuse proliferative type 4 lupus nephritis) were used as control groups. In addition, to analyze the influence of either renal failure or hemodialysis therapy on serum Lam-P1 levels, 91 patients on regular hemodialysis therapy and 81 patients with predialysis chronic renal failure of different etiologies were included in the study. Serum Lam-P1 was determined by RIA at admission, on days 10 and 30 of follow-up in all patients, and after 6 and 12 mo of follow-up in all surviving patients. Serum lactate dehydrogenase, haptoglobin, platelet count, hemoglobin, and serum creatinine were determined as markers of endothelial dysfunction and hemolysis. At admission, serum levels of Lam-P1 were significantly higher in patients with TMA than in healthy control subjects (3.39 +/- 0.56 U/ml versus 1.40 +/- 0.18 U/ml; P < 0.0001). In addition, patients with TMA had significantly higher serum Lam-P1 levels than the other groups included in the study. At the first control, Lam-P1 correlated with lactate dehydrogenase (P = 0.006) and hemoglobin (P = 0.002). During follow-up, platelet count and hemolysis indicators normalized in all patients, while serum Lam-P1 decreased only in patients with renal function recovery. In multivariate analysis, serum creatinine and Lam-P1 at day 10 were the only independent predictors of renal outcome (r2 = 0.94; P < 0.0001) and also correlated with indices of histopathologic damage (P < 0.001). Serum Lam-P1 normalized in all patients with chronic renal failure in the samples obtained at 6 and 12 mo of regular hemodialysis after solving active TMA, thus suggesting that histopathologic lesions, but not renal function itself, would be mainly responsible for the high Lam-P1 serum concentrations detected in TMA. In conclusion, serum Lam-P1 concentrations are increased in patients with active TMA. Furthermore, patients with poor renal outcome show a prolonged increase of serum Lam-P1 that is related to the extent of renal histologic lesions. Unlike the biochemical markers of hemolysis commonly used to assess TMA activity, the sequential determination of serum Lam-P1 provides valuable information about long-term renal prognosis in patients with TMA.

Basement membrane peptides as markers of liver disease in chronic hepatitis C

BACKGROUND/AIM

Chronic hepatitis C is characterised by slow progression to liver fibrosis. In liver fibrosis, basement membrane components are increasingly deposited around the vessels and in the portal tracts. Serum assays can measure the two major components of the basement membrane, type IV collagen and laminin. The aim of this study was to determine whether serum levels of type IV collagen and laminin are related to severity of liver injury in chronic hepatitis C.

METHODS

Thirty-seven patients with chronic hepatitis C (CHC) and five healthy controls were studied. Serum type IV collagen was measured by a one-step sandwich EIA kit (Fuji, Japan) and serum laminin was measured by RIA (CIS, UK). Liver biopsies in patients with CHC were scored using a previously described grading and staging system. Liver biopsy scores were compared to serum levels of laminin, type IV collagen and alanine aminotransferase (ALT). Receiver operating characteristic (ROC) analysis was used to compare the ability of the assays to detect advanced liver injury.

RESULTS

The median serum concentration of type IV collagen was 127.1 ng/ml (range 17.7 to 317.4) in CHC patients compared to a median of 61.3 ng/ml (range 11.5 to 102.3) in controls, p=0.006. The median serum concentration of laminin was 1.12 U/ml (range 0.74 to 2.46) in CHC compared to a median of 0.87 U/ml (range 0.83 to 1.06) in controls, p=0.07. Both serum type IV collagen and laminin were significantly correlated with the fibrotic stage and also with the necroinflammatory injury scores- histological activity index, portal inflammation and periportal hepatitis. Serum ALT was significantly correlated with portal inflammation. Using ROC analysis, the area under the curve for type IV collagen and laminin was 0.83 (p=0.001) and 0.82 (p=0.0017), respectively, while the area under the curve for ALT was 0.54 (p=0.1).

CONCLUSIONS

Serum assays of basement membrane peptides are accurate non-invasive markers of liver fibrosis and liver inflammation in chronic hepatitis C. These markers are superior to serum ALT in reflecting liver injury and they have high specificity and sensitivity in detecting advanced liver disease in chronic hepatitis C.

High serum laminin concentrations in patients with Candida sepsis

BACKGROUND

Laminin, a major component of the basement membrane, plays a critical role in normal cell adhesion and also during tissue invasion of pathogenic microorganisms.

MATERIALS AND METHODS

Serum laminin concentrations were determined in 19 patients with Candida albicans sepsis, in 13 patients with bacterial sepsis and in 20 noninfectious controls.

RESULTS

Serum laminin concentrations of both, patients with candidal and bacterial sepsis, were significantly elevated compared to the controls (486 ng mL-1 [155-924], median [range]; P < 0.01). Laminin concentrations were significantly higher in patients with Candida sepsis than in patients with bacterial sepsis on day 1 (2565 ng mL-1 [659-6064] vs. 994 ng mL-1 [386-2064]; P < 0.01), day 7 (1594 ng mL-1 [607-4611] vs. 684 ng mL-1 [284-1920]; P < 0.05) and day 14 (1444 ng mL-1 [202-2131] vs. 386 ng mL-1 [180-1658]; P < 0.05).

CONCLUSIONS

Laminin serum concentrations might be useful to differentiate nonbacterial, bacterial and fungal etiology.

Serum laminin and type III procollagen in chronic hepatitis C. Diagnostic value in the assessment of disease activity and fibrosis

Laminin P1 (pepsin-resistant fragment of laminin) and aminoterminal peptide of type III procollagen are measurable in serum and are now considered useful serum markers of fibrogenesis and inflammation in chronic liver diseases. However, very few studies thus far have focused on assessing the diagnostic value of these markers in detecting fibrosis and necro-inflammatory activity in chronically diseased liver. The aim of the present study was therefore to investigate the correlations of laminin and type III procollagen with liver histology and to compare their diagnostic value in detecting the degree of liver fibrosis and necro-inflammatory activity in a homogeneous group of 99 patients suffering from chronic hepatitis C, and lacking other factors which can directly affect the serum levels of the two markers. Both these serum markers were measured by radioimmunoassay, employing commercially available kits. The three main aspects of liver pathology, i.e. portal-periportal activity, lobular activity and fibrosis, were histologically evaluated and semiquantitatively expressed by numerical scores. The results of this study show that laminin and type III procollagen were both positively correlated with the histological scores for portal-periportal activity and with those for fibrosis, whereas no significant correlation was observed between each of the two serum markers and the histological scores for lobular activity. The sensitivity and specificity of laminin and type III procollagen in detecting histological aspects of fibrosis and disease activity in liver, computed at various cut-off levels, showed overlapping trends for the two markers; however, the diagnostic value was in general rather low, whatever the cut-off considered. We therefore conclude that the 'static' measurement of both serum laminin and type III procollagen is of limited value for individual diagnosis of liver damage.