Diagnostic Value of Serum Procollagen Peptide Measurements in Alcoholic Liver Disease

Procollagen type I carboxyterminal and type III aminoterminal peptide concentrations were measured in sera of 60 patients with alcoholic and 14 with nonalcoholic liver disease to study whether these assays are useful as clinical tests to differentiate various stages of alcoholic liver injury. Both propeptides were markedly elevated in alcoholic hepatitis and cirrhosis: procollagen type III peptide in 90% and type I peptide in 60-80% of these patients. Moderately increased values were found less frequently in patients with fatty liver. These tests did not differentiate patients with simple fatty liver from those with fatty liver and early fibrosis. There was a significant difference in serum procollagen type III peptide between fatty liver and both alcoholic hepatitis and cirrhosis (p less than 0.001), and in type I peptide between fatty liver and alcoholic hepatitis (p less than 0.005). Although serum peptide values correlated with the degree of liver fibrosis, appreciable overlap of values was found between the various groups. The peptide concentrations also seemed to be related to the degree of hepatic inflammation, and the highest values were observed in a subgroup of patients with alcoholic hepatitis in whom numerous Mallory bodies were found. The data suggest that in alcoholic liver diseases, serum collagen propeptide determination may be useful in diagnosing severe alcoholic hepatitis.     

Serum Type I Collagen and N-terminal Peptide of Type III Procollagen in Patients with Alcoholic Liver Disease: Relationship to Liver Histology

This study compared, in patients with alcoholic liver disease, the serum concentration of N-terminal peptide of type III procollagen and of a novel serum marker, type I collagen, with liver histological data and assessed the role of these markers in the diagnosis and follow-up of liver changes. Ninety-six patients (mean age 51 years, 61 men and 35 women) were included. All had alcoholic liver disease diagnosed on usual clinical, biochemical, and histological criteria. Two histological scores, one for alcoholic hepatitis and one for fibrosis, were established. Serum N-terminal peptide of type III procollagen and type I collagen were assayed by liquid phase radioimmunoassay. Significant correlations between serum type I collagen and score of fibrosis (r = 0.34, p less than 0.001) and between serum N-terminal peptide of type III procollagen and score of alcoholic hepatitis (r = 0.60, p less than 0.0001) were noted. There was no significant correlation between serum aminotransferases and the score of alcoholic hepatitis. In 25 patients with alcoholic hepatitis reassessed between 3 and 6 months, serum N-terminal peptide of type III procollagen significantly decreased (p less than 0.05) as did the score of alcoholic hepatitis, but serum type I collagen and the score of fibrosis were not modified. These serum markers of collagen metabolism could be useful for the assessment and follow-up in patients with alcoholic liver disease.     

Serum laminin and portal pressure in alcoholic cirrhosis. A study of 39 patients

A correlation between serum laminin, a glycoprotein found in basement membranes, and hepatic wedge pressure has previously been reported in a small number of patients with various liver diseases. To study this relationship in patients with alcoholic cirrhosis, we measured the wedge hepatic pressure and venous gradient, in comparison with serum concentrations of laminin and collagen metabolism products: N-terminal peptide of type III procollagen, collagen type I, and collagen type III in 39 patients. A statistically significant correlation was observed between serum laminin and wedged hepatic pressure (r = 0.529; p less than 10(-3] or hepatic venous gradient (r = 0.482; p = 0.002). By contrast, no statistically significant correlation was found between hemodynamic parameters and serum concentrations of N-terminal peptide of type III procollagen, collagen type I or collagen type III. These results suggest that, in patients with alcoholic cirrhosis, portal pressure may be estimated by serum concentration of laminin, and that perisinusoidal fibrosis, especially basement membrane thickening, may play an important role in the pathogenesis of portal hypertension in these patients.     

Splanchnic and renal extraction of circulating type III procollagen aminoterminal propeptide in patients with normal liver function and in patients with alcoholic cirrhosis

Splanchnic and renal extraction of circulating aminoterminal propeptide of type III procollagen and related antigens were studied in 12 patients with normal liver function and in 19 patients with alcoholic cirrhosis during catheterization. Type III procollagen peptide in serum was measured in two assays: the Type III Procollagen Peptide Radioimmunoassay Kit, a new assay that selectively determines the intact propeptide (and larger type III propeptide-holding antigens) and the Type III procollagen Fab assay that measures both the intact propeptide and the smaller fragments that quantitatively dominate in serum. A significant decrease in the concentration of the intact propeptide between the artery and the hepatic vein was found in the group with normal liver function (p less than 0.01) and in patients with cirrhosis (p less than 0.01). In patients with cirrhosis, however, the splanchnic extraction ratio of the intact propeptide (median = 0.04, range = -0.03 to 0.16) was significantly lower than in patients with normal liver function (median = 0.17, range = 0.05 to 0.36, p less than 0.01). The concentration of the intact propeptide in the hepatic vein was positively correlated to hepatic pressure (n = 18, r = 0.51, p less than 0.05) and inversely correlated to indocyanine green clearance (n = 15, r = -0.61, p less than 0.05). No splanchnic extraction could be demonstrated in the Type III propeptide Fab assay. A significant renal extraction was found in the Fab assay, but not in Type III Procollagen Peptide Radioimmunoassay Kit.(ABSTRACT TRUNCATED AT 250 WORDS)     

Serum type I collagen and N-terminal peptide of type III procollagen in chronic hepatitis. Relationship to liver histology and conventional liver tests.

The aim of this study was to compare serum N-terminal peptide of type III procollagen to aminotransferases and gamma-globulins as a marker for histological activity in patients with chronic hepatitis and to assess the role of type I collagen, a new serum marker, as a marker of fibrosis in these patients. Sixty patients with biopsy-proven chronic hepatitis were included in this study. Liver disease was virus B-related in 29, autoimmune in five, drug-induced in five, and of unknown etiology in 21. Each biopsy was independently assessed by two liver pathologists. Two histological scores, a score of activity and a score of fibrosis, were established. Serum N-terminal peptide of type III procollagen and type I collagen were assayed by liquid phase RIA. Significant correlations were noted between serum N-terminal peptide of type III procollagen and scores of activity (r = 0.70, p less than 10(-4)) and fibrosis (r = 0.45, p = 0.0005), and between serum type I collagen and scores of activity (r = 0.46, p = 0.0004) and fibrosis (r = 0.67, p less than 10(-4)). When the correlation between scores of activity and fibrosis (r = 0.52, p = 10(-4)) was considered by partial correlation, serum N-terminal peptide of type III procollagen was correlated with the score of activity (r = 0.63, p less than 10(-3)) but not with the score of fibrosis, and serum type I collagen was correlated with the score of fibrosis (r = 0.58, p less than 10(-3)), but not with the score of activity.(ABSTRACT TRUNCATED AT 250 WORDS)     

Biliary excretion of procollagen type III peptide in healthy humans and in patients with alcoholic cirrhosis of the liver

Serum concentrations of procollagen type III peptide are found to be elevated in liver disease and to correlate with fibrosis activity in liver tissue. These elevated serum levels may be due to enhanced synthesis, decreased excretion, or release from deposits of the propeptide in connective tissue. To quantitatively investigate the excretion of procollagen type III peptide, we studied its presence in the bile and urine of 10 healthy controls and 11 patients with alcoholic cirrhosis of the liver. Biliary excretion rates of procollagen propeptide were determined by the duodenal perfusion method. The serum concentrations of procollagen type III peptide were 2.5 +/- 0.5 ng/ml in the healthy controls and 33.6 +/- 6.8 ng/ml in the patients with cirrhosis. Procollagen type III peptide was found in the bile; the healthy controls excreted 0.4 +/- 0.07 nmol/h and the cirrhotics excreted 0.98 +/- 0.27 nmol/h. A fragment of the procollagen propeptide, Col 1, was excreted in urine; the healthy controls excreted 0.25 +/- 0.04 nmol/h, and the cirrhotics excreted 0.11 +/- 0.03 nmol/h. These data demonstrate that the biliary excretion of procollagen type III peptide represents a quantitatively important pathway.     

Serum Type I Collagen Propeptide and Severity of Alcoholic Liver Disease

We assessed the relationship of serum type I collagen propeptide concentrations with various severity indices of alcoholic liver disease, including clinical and morphological severity, the amount of alcohol consumption, and the serum levels of other components of connective tissue. The serum concentration of the carboxyterminal propeptide of type I procollagen (PICP) was measured with a new radioimmunoassay that is devoid of a crossreaction caused by type III procollagen-derived fragments. A significant correlation was found between serum PICP and the Combined Clinical and Laboratory Index (CCLI) (rs = 0.58, p < 0.001) and the Combined Morphological Index (CMI) (rs = 0.57, p < 0.01). However, PICP was elevated less frequently than serum type III collagen propeptide (PIIINP), type IV collagen or laminin, and the correlations with the latter three parameter with both the CCLI (PIIINP: rs = 0.80, type IV collagen: rs = 0.80; and laminin: rs = 0.81) or CMI (PIIINP: rs = 0.75, type IV collagen: rs = 0.72; and laminin rs = 0.61) were all stronger than that of PICP. Furthermore, although during a follow-up period of 6 months, the mild or moderately drinking patients had a significant decrease in PIIINP and the heavily drinking patients had no improvement. PICP was, however, found to improve in both the mild and heavy drinkers. These results point to differences in handling of type I and type III collagen propeptides in alcoholic liver disease. The latter appears to be a more sensitive indicator of disease severity, presence of alcoholic hepatitis, and the amount of alcohol intake.     

Schistosoma mansoni infection in a recently exposed community in Senegal: lack of correlation between liver morphology in ultrasound and connective tissue metabolites in serum

Summary Four hundred and seventy villagers of Ndombo, a village with recently established intensive transmission of Schistosoma mansoni in the Senegal River Basin, were enrolled in a study with the intention to assess hepatosplenic morbidity. All patients were examined parasitologically and by ultrasound. Hepatic fibrosis serum markers were determined in 153 adult patients (aminoterminal propeptide of procollagen type III, hyaluronan and laminin). By ultrasound, about 60% of the patients showed early stages of hepatic involvement, 3% of the patients unequivocally showed severe hepatosplenic pathology (grade 3 according to the Managil classification), whereas in another study performed in the same village 3 years earlier, no patients with severe hepatosplenic pathology had been found. No correlation between the aminoterminal propeptide of procollagen type III, hyaluronan or laminin and the ultrasound findings could be established. These hepatic fibrosis serum markers do not seem to be a sensitive method to detect early hepatic fibrosis in schistosomiasis.     

Hepatic fibrosis in rats produced by carbon tetrachloride and dimethylnitrosamine: observations suggesting immunoassays of serum for the 7S fragment of type IV collagen are a more sensitive index of liver damage than immunoassays for the NH2-terminal propeptide of type III procollagen.

Liver fibrosis was induced in rats both with carbon tetrachloride and dimethylnitrosamine. Assays were performed on steady-state levels of messenger RNAs in the liver for several collagens and basement membrane components. The results indicated marked increases in the steady-state levels of messenger RNA for type I collagen, type III collagen, type IV collagen and the B2 component of laminin. In the same animals, immunoassays were performed for serum levels of the N-terminal propeptide of type III procollagen and the 7S fragment of type IV collagen. The results demonstrated an increase in the serum levels of 7S fragment that occurred early and closely paralleled the increase in the steady-state levels of messenger RNA for the alpha 1(IV) chain of type IV collagen. In contrast, no significant increase was seen in the serum levels of the N-propeptide of type III procollagen. The results suggest that immunoassays for 7S fragment of type IV collagen in serum are a more sensitive index for liver cell damage and fibrosis than assays for the N-propeptide of type III procollagen. The results suggest that greater attention should be paid to assays of 7S fragments in assessing hepatic fibrosis in man.     

Serum type III procollagen peptide and laminin (Lam-P1) detect alcoholic hepatitis in chronic alcohol abusers

The diagnosis of alcoholic hepatitis is difficult to establish by conventional clinical and laboratory methods, and a firm diagnosis relies on liver histology. Since there are severe limitations in following patients with repeated liver biopsies, noninvasive procedures are needed to assess the presence of alcoholic hepatitis in chronic alcohol abusers. It has been suggested that serum Type III procollagen peptide levels correlates with the degree of inflammation in chronic liver disease. Since inflammation is a major histological finding in alcoholic hepatitis, we therefore studied the usefulness of measuring serum Type III procollagen peptide and laminin values in 45 consecutive chronic alcohol abusers, with or without cirrhosis, in detecting those with alcoholic hepatitis. The results showed that both Type III procollagen peptide and laminin values were elevated in all of the patients with established liver damage. However, the values were highest in those with liver cirrhosis plus alcoholic hepatitis (Type III procollagen peptide 50.4 +/- 36.4 ng per ml vs. 8.1 +/- 2.6 in controls, p less than 0.01; laminin 4.50 +/- 1.49 units per liter vs. 1.24 +/- 0.26 units per liter in controls, p less than 0.01), followed by subjects with alcoholic hepatitis alone (Type III procollagen peptide 23.5 +/- 17.6 ng per ml, p less than 0.01; laminin 2.60 +/- 1.09 units per liter, p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)     

慢性乙型肝炎肝纤维化分期与血清肝纤维化标志物的相关性分析

目的 探讨血清透明质酸、Ⅲ型前胶原、层粘蛋白、Ⅳ型胶原等血清肝纤维化标志物与慢性肝炎肝组织炎症活动度及纤维化程度的相关性。方法 278例慢性肝炎患者经肝脏活栓后常规病理检查,肝活检前同时采血检测血清透明质酸、Ⅲ型前胶原、层粘蛋白、Ⅳ型胶原,结果应用x^2检验及t检验进行统计学处理。结果 肝组织纤维化程度与炎症活动度呈正相关关系,透明质酸可反映中度以上慢性肝炎炎症活动度及纤维化程度,且呈正相关;肝脏存在纤维化时层粘蛋白水平升高,与纤维化程度正相关;Ⅲ型前胶原、Ⅳ型胶原水平升高与炎症活动度有关。结论 血清透明质酸、Ⅲ型前胶原、层粘蛋白、Ⅳ型胶原可不同程度反映肝纤维纤维化程度,可作为血清肝纤维化检测指标,透明质酸更可反映肝硬化发展趋势。     

Albumin and collagen gene regulation in alcohol- and virus-induced human liver disease

Common features of chronic alcoholic liver disease are progressive hypoalbuminemia and a spectrum of liver fibrosis. The molecular mechanisms that account for these effects are still the subject of controversy. Therefore, in the present study we evaluated albumin and collagen gene expression in livers of alcohol abusers and patients with virus-induced liver disease. Albumin and pro alpha 1(I) collagen messenger RNA levels were determined in 30 patients who underwent diagnostic liver biopsy. Of 14 alcoholics, 7 had alcoholic hepatitis alone and the other 7 had cirrhosis plus alcoholic hepatitis. Of 16 nonalcoholic patients with chronic viral infection, 6 had chronic active hepatitis and 10 had cirrhosis plus chronic active hepatitis. Total RNA was extracted from a portion of each biopsy specimen, hybridized with a human albumin or collagen complementary DNA clone, and compared with 2 normal surgical specimens, which served as controls. The Northern hybridization studies showed that (a) despite the presence of inflammation and fibrosis, the albumin messenger RNA levels of alcoholics were similar to those of the controls; (b) these alcoholics had significantly higher levels of albumin messenger RNA than did patients with similar histological levels of disease due to viral infection; and (c) all the categories of patients had markedly increased procollagen messenger RNA levels compared with controls. Given these results it is tempting to speculate that alcohol may actually increase albumin messenger RNA content in humans as it does in animals. Furthermore, the increased procollagen messenger RNA levels in fibrotic livers suggest that an increase in collagen syntheses may be a significant factor in the pathogenesis of hepatic fibrosis.     

Evaluation of hepatic fibrosis by serum proline and amino-terminal type III procollagen peptide levels in alcoholic patients

In patients with alcoholic liver disease, serum proline and amino-terminal type III procollagen peptide levels were evaluated as a marker of hepatic fibrosis. Thirty-one patients with alcoholic liver disease (2 with nonspecific change, 3 with alcoholic hepatitis, 17 with hepatic fibrosis without cirrhosis, and 9 with cirrhosis) and 15 controls were investigated. Hepatic fibrosis was estimated in each liver biopsy specimen by morphometric analysis, and the ratio of fibrotic change to total area (AREA-F) was calculated by morphometric analysis. In patients with hepatic fibrosis, serum proline levels and routine liver function tests were not significantly correlated to AREA-F value, while serum peptide levels showed a significant positive correlation to AREA-F value (r=0.733,P<0.001). These results suggest that the determination of serum amino-terminal type III procollagen peptide level may serve as a good marker for the diagnosis of liver fibrosis in the alcoholic.This study was supported in part by grants 57570273 and 59480207 from the Japanese Ministry of Education, Science and Culture.     

Renal function and morphology in Sudanese patients with advanced hepatosplenic schistosomiasis and portal hypertension

The association between glomerular disease and hepatosplenic schistosomiasis is well documented in reports from South America. During the present hospital investigation in Sudan, 58 patients admitted for intercurrent complications of advanced hepatosplenic schistosomiasis were studied. The patients, median age 35 years, had no concurrent Schistosoma haematobium infection. Diagnostic criteria included an enlarged spleen (n = 58), at least 1 episode of hematemesis (n = 55) and/or melena (n = 36), endoscopical demonstration of gastroesophageal varices (29/29 studied), ultrasonographical imaging of hepatic periportal fibrosis (18/18 studied), and intraoperative liver biopsy with characteristic histological findings (11/16 biopsied). Serum creatinine, urea, electrolytes, cholesterol, total protein, and electrophoresis were within normal limits. Median urinary protein/creatinine ratio was 0.06 and thereby not significantly different from European reference values. Only 1 patient had proteinuria of 1.7 g/l. Minimal hematuria was found in 5 patients. Ten kidney biopsies were taken intraoperatively during a portal decompression procedure (Hassab operation). Light, immunofluorescence, and electron microscopy produced no evidence of glomerulonephritis. These findings indicate that S. mansoni induced nephrotic syndrome may be less frequent in Sudan than in South America. Renal involvement due to S. mansoni infection may therefore encompass geographical variances.     

Markers of fibrogenesis and basement membrane formation in alcoholic liver disease. Relation to severity, presence of hepatitis, and alcohol intake.

This study investigated the relationships of the serum markers of fibrogenesis and basement membrane formation to the clinical and morphological severity of alcoholic liver disease and to the degree of alcohol abuse. The concentrations of the aminoterminal propeptide of type III collagen, type IV collagen, and laminin were measured from 87 samples representing a wide range of clinical and histological severities of the disease, which were assessed with indices that have been shown to correlate well with the risk of dying within 1 yr. Significant correlations (p less than 0.00001) were found between the markers of connective tissue metabolism and the Combined Clinical and Laboratory Index: (aminoterminal propeptide of type III collagen, rs = 0.82; type IV collagen, rs = 0.82; laminin, rs = 0.81), as well as between these markers and the Combined Morphological Index: (aminoterminal propeptide of type III collagen, rs = 0.70; type IV collagen, rs = 0.68; laminin, rs = 0.64). Whereas the patients with less than 8 mM of alcohol in their morning urine (mild or moderate drinkers) showed a significant (p less than 0.00001) decrease in these markers in a period of 27 +/- 1 wk, the patients with more than 8 mM of urinary alcohol (heavy drinkers) had no improvement. It is proposed that both fibrogenesis and basement membrane formation are associated with disease severity, degree of alcoholic hepatitis, and alcohol intake, which are important determinants of prognosis in alcoholic liver disease.     

Localisation and semiquantitative assessment of hepatic procollagen mRNA in primary biliary cirrhosis

Background—Chronic liver disease ischaracterised by excessive deposition of collagen and otherextracellular matrix proteins, produced mainly, but not exclusively, byactivated hepatic stellate cells in the perisinusoidal space. Inprimary biliary cirrhosis (PBC) fibrosis is concentrated mainly aroundthe portal tracts.
Aims—To examine the hypothesisthat, in addition to hepatic stellate cells, portal tract fibroblastsmight play a significant role in the deposition of collagen in PBC.
Methods—Fifty liver biopsyspecimens from patients with PBC were studied. An in situ hybridisationtechnique was adapted to localise and measure semiquantitatively type Iprocollagen mRNA in formalin fixed, paraffin wax embedded sections,using an ³⁵S labelled cRNA probe specific for theα₁ chain of rat type I procollagen. Hepatic fibrogenicactivity was also assessed using serum type III procollagen peptide (PIIINP).
Results—In PBC, type I procollagengene expression was significantly increased. Signal was localisedmainly in and around inflamed portal tracts, to cells which had theappearances of portal fibroblasts. Signal activity in these cellscorrelated with the degree of portal fibrosis and inflammation and alsowith serum PIIINP concentrations.
Conclusions—Results are consistentwith the hypothesis that the excessive extracellular matrix, depositedwithin the liver in PBC, is synthesised not only by hepatic stellatecells but also by portal tract fibroblasts. The semiquantitativeassessment of procollagen mRNA in liver biopsy specimens may provide auseful method of evaluating the rate of synthesis of collagen andtherefore disease activity in patients with PBC.

Keywords:in situ hybridisation; procollagen peptide; primarybiliary cirrhosis; hepatic fibrosis

     

Comparison of assays for N-amino terminal propeptide of type III procollagen in chronic hepatitis C by using receiver operating characteristic analysis.

OBJECTIVE: During the process of liver fibrosis, type III procollagen is converted to type III collagen by cleavage of its amino terminal and carboxy terminal propeptides. Serum levels of amino terminal propeptide of type III procollagen (PIIINP) are a marker of collagen turnover in liver fibrosis. Two assays for PIIINP are available, one which measures both Col 1-3 (collagen synthesis) and Col 1 (collagen degradation) peptides, and one which measures Col 1-3 only. Using receiver operating characteristic analysis, the two PIIINP assays were compared with serum ALT as markers of liver disease in chronic hepatitis C. METHODS: Serum PIIINP was measured using both assays in 33 patients with chronic hepatitis C and five healthy controls. Liver biopsies in chronic hepatitis C patients were scored using a previously described grading and staging system. RESULTS: Serum PIIINP was significantly elevated in chronic hepatitis C compared to controls using both the combined Col 1-3 and Col 1 (median 0.61 vs 0.33 U/ml, P=0.001) and Col 1 assays (median 6.5 vs 3.5 microg/l, P=0.006). Serum PIIINP measured by the combined assay was significantly related to liver fibrosis, periportal necrosis and histological activity index (P<0.05). The area under the curve for specificity and sensitivity in detecting advanced liver disease was only significant for the combined assay (P=0.017). Serum PIIINP measured by the Col 1 assay was not related to these indices of disease severity while serum ALT was only related to portal inflammation. CONCLUSION: A serum PIIINP assay which measures both Col 1-3 and Col 1 peptides instead of Col 1-3 peptide alone is more predictive of severity of liver disease and should be used in preference as a non-invasive marker of liver injury in chronic hepatitis C.     

Collagen type I and III occur together in hybrid fibrils in the space of Disse of normal rat liver

Collagen type I and procollagen type III were localized at the ultrastructural level on ultrathin frozen sections of rat liver by the protein A-gold technique using affinity-purified primary antibodies. Both collagen type I and procollagen type III were localized on nearly all solitary and bundled fibrils in the space of Disse. Simultaneous localization of collagen type I and procollagen type III by a double-labeling procedure using protein A-gold probes of different sizes unequivocally demonstrated the presence of both collagens in the same fibrils. Measurement of the diameter of large numbers of collagen fibrils in the space of Disse of the rat liver showed a unimodal distribution of the fibril diameters around an average value of 62.4 nm (S.D. = 12.8 nm), and 91% of the collagen bundles contained less than 30 fibrils. Additional measurements on epoxy resin-embedded material of five biopsy specimens of normal human liver showed a comparable unimodal distribution of the fibril diameters around an average value of 57.2 nm (S.D. = 9.6 nm), and 74% of the bundles contained less than 60 fibrils. The latter observation demonstrates that human liver contains broader interstitial collagen bundles than rat liver. From these results, we conclude that the space of Disse of normal rat and human liver contains a uniform population of striated interstitial collagen fibrils. In the rat liver, these fibrils contain both collagen type I and procollagen type III. Therefore the concept that procollagen type III is predominantly localized in small diameter fibrils or bundles, whereas collagen type I is preferentially localized in thick ones, does not hold.