Basement membrane-related and type III procollagen-related antigens in serum of patients with chronic viral liver disease

To assess the significance of serum basement membrane- and type III procollagen-related antigens in reflecting the degree of liver fibrosis, we measured radioimmunologically the concentrations of 7S collagen, laminin fragment P1, and the aminoterminal propeptide of type III procollagen (P-III-P) in serum from 48 patients with chronic viral liver disease: chronic persistent hepatitis (9), chronic active hepatitis (13), chronic active hepatitis with lobular disorganization (17), and liver cirrhosis (9). Concentrations of 7S collagen, laminin P1, and P-III-P in serum were increased in respectively 92%, 69%, and 77% of the patients with both chronic active hepatitis with lobular disorganization and liver cirrhosis. Concentrations of 7S collagen and laminin P1 in serum correlated well (r = 0.65, P less than 0.001, and r = 0.55, P less than 0.001, respectively) with the histological grade of liver fibrosis, whereas P-III-P correlated only weakly (r = 0.33, P less than 0.05). Evidently, measurement of serum 7S collagen is a reliable noninvasive test for detection of fibrosis in chronic viral liver disease.     

Serum enzymes of collagen synthesis and type III procollagen amino-propeptide in Nigerian patients with sickle cell disease

Serum immunoreactive prolyl hydroxylase protein, galactosylhydroxylysyl glucosyltransferase activity and the aminoterminal propeptide of type III procollagen were measured in 20 patients with sickle cell disease and the values were compared with those in 20 apparently healthy Nigerians. The means for the two enzymes and serum aminoterminal propeptide of type III procollagen were significantly higher in the sickle cell disease patients. Significant correlations were found between the values for the two enzymes and the protein serum aminoterminal propeptide of type III procollagen within the sickle cell disease patients. The data confirm that collagen formation is found in the liver, bone and other organs of patients with this disease. The measurement of serum immunoreactive prolyl hydroxylase protein, serum galactosylhydroxylysyl glucosyltransferase activity and serum aminoterminal propeptide of type III procollagen in prospective studies might be helpful in predicting hepatic, bone or diffuse fibrogenesis in sickle cell disease.     

Collagen biosynthesis enzymes in serum and hepatic tissue in liver disease

Abstract. Serum immunoreactive prolyl hydroxylase protein was measured in sixty-five patients with liver disease, and liver prolyl hydroxylase activity, immunoreactive prolyl hydroxylase protein and collagen hydroxyproline in forty of these patients. Serum immunoreactive prolyl hydroxylase protein was above the 95% confidence limit of the controls in most patients with primary biliary cirrhosis, portal cirrhosis, acute hepatitis and cancer with liver metastases, but below this in most patients with fatty liver, chronic active hepatitis, extrahepatic cholestasis, cholangitis, cancer without liver metastases and other malignant diseases. Elevated serum immunoreactive prolyl hydroxylase protein decreased rapidly with time in acute hepatitis but not in primary biliary cirrhosis. Liver prolyl hydroxylase activity and immunoreactive prolyl hydroxylase protein were elevated in the same diseases as serum immunoreactive prolyl hydroxylase protein, and correlated significantly with the latter whereas no correlation was found between serum immunoreactive prolyl hydroxylase protein and collagen hydroxyproline. Serum immunoreactive prolyl hydroxylase protein correlated highly significantly with serum alkaline phosphatase and weakly with serum aspartate aminotransferase in primary biliary cirrhosis, but not in any other disease. No correlation was found between serum immunoreactive prolyl hydroxylase protein and other tests of liver function. The results suggest that changes in serum immunoreactive prolyl hydroxylase protein in liver disease primarily reflect changes in this enzyme in the hepatic tissue, and that assays of serum immunoreactive prolyl hydroxylase in liver disease may give useful information on the actual hepatic collagen synthesis.     

Collagen type IV and procollagen type III during granulation tissue formation: a serological, biochemical, immunohistochemical and morphometrical study on the viscose cellulose sponge rat model

The serum concentrations of collagen type IV,7S, collagen type IV,nc1, and aminoterminal type III procollagen peptide immunoreactive components were measured by means of specific radioimmunoassays during development of granulation tissue in rats. The results were compared with tissue deposition of basement membranes and interstitial collagens in the granulation as measured morphometrically. A parallel sequential pattern in tissue deposition of collagen types III and IV, and serum increase of collagen types III- and IV-related fragments, was observed. Serum collagen type IV was less sensitive as a marker for development of granulation tissue than the serum procollagen type III N-peptide. This was in accordance with a low collagen type IV/interstitial collagen ratio in the granulation tissue. However, a cross-sectional study showed that serum collagens types IV,7S and IV,nc1 may be useful as early quantitative indicators of granulation tissue formation. Simultaneously, measurement of collagen type IV- and procollagen type III N-peptide-related antigens in serum provides a differentiated reflection of the dynamic matrix processes in developing granulation tissue.     

Serum type III procollagen peptide as a non-invasive marker of liver damage during infancy and childhood in extrahepatic biliary atresia, idiopathic hepatitis of infancy and alpha 1 antitrypsin deficiency

To evaluate the role of serum procollagen III peptide as a non-invasive marker of liver damage and prognosis in hepatobiliary disorders of infancy, we have measured its concentration at presentation and serially in 30 infants with extrahepatic biliary atresia, 22 with idiopathic hepatitis of infancy, 10 with alpha 1 antitrypsin deficiency and 105 age-matched controls. Raised procollagen III peptide concentrations occurred in 51% of patients at presentation and 59% at follow up but were not related to the type of liver disease or the severity of liver damage, as assessed either by standard biochemical tests of liver function, serum glycocholic acid, semiquantitative assessment of 11 histopathological features or hepatic prolyl hydroxylase activity. Serum procollagen III peptide concentrations also gave no guide to prognosis. Although the factors determining serum procollagen III peptide concentrations in hepatobiliary disorders of infancy are unknown at the present time, we suggest that changes in growth rate may be of major importance in determining the significance of serum procollagen III peptide concentrations in infants and children.     

Radioimmunoassay for the carboxy-terminal cross-linking domain of type IV (basement membrane) procollagen in body fluids. Characterization and application to collagen type IV metabolism in fibrotic liver disease.

The carboxy-terminal cross-linking domain (NCl) of type IV procollagen was isolated from human placenta and used for the production of polyclonal and monoclonal antibodies. Purity of the antigen and specificity of the antibodies were verified by Western blotting and radioimmunoassays. A radioimmunoassay was developed using rabbit antiserum. Intra- and interassay coefficients of variation were 4.7% and 5.8%, respectively; recovery of NCl added to serum and bile was 95-105%. NCl concentration in sera of healthy volunteers was 6 +/- 2.9 ng/ml (mean +/- 2.5 SD) and was elevated up to 18 ng in sera of patients with autoimmune or metastatic tumor disease and up to 240 ng in sera of patients with fibrogenic liver disease. Substantial amounts of antigen were also found in bile, urine, and ascites. 67% of serum antigens eluted from an agarose A5M column with an apparent molecular weight of 60 kD and 23% with a molecular weight of 90 and 150 kD, well below the molecular weight of type IV procollagen (550 kD). Serum NCl is apparently derived from the degradation of basement membrane collagen. The time course of NCl concentrations in sera of patients with fibrogenic liver disease showed no correlation with the serum concentration of the amino-terminal procollagen type III peptide, a marker of hepatic collagen biosynthesis. A decline of serum NCl levels along with elevated serum procollagen type III peptides apparently indicates bad prognosis in fibrogenic liver disease. The radioimmunoassay for NCl is a useful tool for studying type IV collagen metabolism in conditions causing remodeling or breakdown of basement membranes.     

Enzymes of collagen synthesis and type III procollagen amino-propeptide in serum from Nigerians with chronic endomyocardial fibrosis

The hallmark of cardiac pathology in chronic African endomyocardial fibrosis is the laying down of excess collagen in the endomyocardium. Preliminary observations on the assay of enzymes of collagen synthesis and type III procollagen aminopropeptide in chronic African endomyocardial fibrosis are reported. Serum immunoreactive prolyl hydroxylase protein was elevated in 4, serum galactosyl-hydroxylysyl glucosyl transferase activity was elevated in 5, and type III procollagen aminopropeptide was also elevated in 5 patients. Cardiac cirrhosis and endomyocardial fibrosis could be responsible for the elevated values in these patients. The relative contribution of fibrosis of the myocardium to these elevated values remains to be clarified.     

Collagen peptidase and type III procollagen peptide serum levels in chronic liver diseases.

The concentration of the N-terminal peptide of procollagen III and the activity of collagen peptidase (PZ-peptidase) were measured in sera from 92 patients with chronic liver disease. In patients with liver cirrhosis and chronic hepatitis with transformation of liver structure, high values were found for both variables compared with hepatoses and chronic hepatitis without transformation. The concentration of procollagen III peptide and the activity of collagen peptidase in serum increased with increasing degrees of fibrosis and, even more markedly, with increasing degrees of mesenchymal activity in the liver.     

Increased serum concentration of type IV collagen peptide and type III collagen peptide in hyperthyroidism.

Serum concentration of type IV collagen peptide, the 7S domain of type IV collagen (type IV collagen 7S) and the amino terminal propeptide of type III procollagen (type III procollagen peptide) is thought to be a useful marker of progressive liver disease. In the present study, serum levels of these collagens in patients with thyroidal diseases with normal liver function were assayed. Increased levels in the hyperthyroid state and relatively decreased levels in the hypothyroid state were observed. The increased levels in hyperthyroidism was most prominent in type IV collagen peptide. The increased level became normal in the subsidence of hyperthyroidism by treatment with anti-thyroid drug. A positive correlation between serum type IV collagen peptide levels and serum thyroid hormone levels such as T4, T3, free T4 and free T3 was observed. These facts show that serum type IV collagen peptide may be influenced by not only liver disease but also serum thyroid hormone levels. Type IV collagen peptide may provide a useful biochemical marker of hyperthyroid state.     

Radioimmunoassay for type III procollagen peptide and its application to human liver disease

A sensitive and specific radioimmunoassay was developed for the precursor-specific peptide segment located at the amino end of bovine type III procollagen. Human material showed high cross-reactivity in this assay. Two forms of human procollagen peptides were detected in body fluids. The larger peptide (45K) was found in serum and ascites, and resembled the whole precursor-specific segment which is presumably released from human type III procollagen by a single enzymatic cleavage. The smaller peptide (10K) was found mainly in urine indicating that further degradation of circulating procollagen peptides is required prior to their passage through the kidney. Compared to peptide concentrations in normal human serum two to twenty-fold increases were observed in all patients with alcoholic liver disease, in fifteen of seventeen patients with acute hepatitis, and in ten of fourteen patients with chronic active hepatitis. Much higher levels were detected in ascites fluid. Patients with rheumatoid arthritis and other diseases showed far smaller elevations of the serum peptide. In alcoholic liver disease peptide levels correlated well with inflammation and necrosis observed in liver biopsies, but not with other laboratory parameters.     

Serum hyaluronate and type III procollagen aminoterminal propeptide concentration in chronic liver disease. Relationship to cirrhosis and disease activity

To analyse the relationship between the presence of liver cirrhosis and hepatic inflammation and the serum concentrations of the aminoterminal propeptide of procollagen type III (P-III-NP) and of hyaluronic acid (HA) in chronic liver disease, we measured P-III-NP and HA concentrations in paired serum samples from 133 patients with various chronic liver diseases, from 22 patients with acute hepatitis and from 50 healthy age-matched controls. In 24 (of the 133) patients with autoimmune chronic liver disease, follow-up determination was performed during therapeutic treatment with immunosuppressive drugs. Compared with controls P-III-NP concentrations (medians) were significantly elevated in 65% of patients with chronic active hepatitis (P = 0.00097) and in 79% of patients with active liver cirrhosis (P = 0.0126) but not in patients with chronic persistent hepatitis (P = 0.06). Serum concentrations (medians) of HA were increased (P = 0.0058) in 32% of patients with chronic active hepatitis and in 91% of patients with active cirrhosis (P less than 6 x 10(-7)). The difference of HA serum concentrations but not that of P-III-NP serum concentrations in patients with chronic active hepatitis and in patients with active cirrhosis was statistically significant. HA and P-III-NP serum concentrations were significantly elevated in 22 patients with acute hepatitis.(ABSTRACT TRUNCATED AT 250 WORDS)     

Raised concentrations of the carboxy terminal propeptide of type IV (basement membrane) procollagen (NC1) in serum and urine of patients with glomerulonephritis

Type IV collagen is a major component of the glomerular and tubular basement membrane. We used a specific radioimmunoassay to determine (mean +/- SD) the concentration of carboxy terminal non-collagenous fragment (NC1) of type IV procollagen in the serum (normal 6.0 +/- 1.2 ng ml-1) and urine (normal 1.5 +/- 2.0 ng ml-1) of 142 patients with various kidney diseases. The 15 patients with active glomerulonephritis displayed (ANOVA, Scheffé test) significantly elevated NCl values in their serum (14 +/- 8.2 ng ml-1) as compared with the 32 patients with chronic interstitial nephritis (7.8 +/- 3.0 ng ml-1), the 17 patients with various other chronic kidney diseases (8.1 +/- 2.4 ng ml-1) and the 23 ambulatory kidney transplant patients (9.1 +/- 1.7 ng ml-1). The highest serum NCl concentrations were found in nine patients with membranoproliferative glomerulonephritis (16 +/- 9.4 ng ml-1). Sequential serum NCl concentrations in the one patient with active Goodpasture's syndrome were marginally elevated (less than 11 ng ml-1). Serum NCl did not increase with acute interstitial rejection episodes in six kidney transplant patients. The highest urinary NCl concentrations were found in seven patients with minimal change glomerulonephritis (7.5 +/- 3.2 ng ml-1). No correlation was found between serum NCl and serum creatinine, NCl and creatinine clearance, or renal NCl clearance and creatinine clearance. There was a significant correlation between serum NCl and proteinuria. Serum and urinary NCl concentrations were elevated independently from renal function, thus indicating intrinsic renal disease.(ABSTRACT TRUNCATED AT 250 WORDS)     

儿童血清4项标志物水平的临床研究

目的 为了解儿童血清透明质酸(HA)、层黏连蛋白(LN)、Ⅲ型前胶原(PcⅢ)、Ⅳ型胶原(CⅣ)水平以及在慢性肝炎中的临床价值.方法 采用酶联免疫吸附试验测定400例1～15岁健康儿童和180例患有慢性肝炎儿童的4项肝纤维化标志物.结果 4项标志物检测结果(x±s)如下:HA(58±16)ng/mL,LN(115±17)ng/mL,PcⅢ(146±27)ng/mL,CⅣ(51±16)ng/mL.HA、CⅣ与年龄不相关(r=-0.022,P>0.05;r=0.070,P>0.05),而LN与年龄显著相关(r=0.128,P<0.01),PcⅢ与年龄呈负相关(r=-0.669,P<0.01).慢性乙型肝炎表面抗原携带者与同龄对照组差异无统计学意义.轻度慢性肝炎患儿除HA显著高于对照组,差异有统计学意义(P<0.05)外,其他3项差异均无统计学意义.中度、重度及肝硬化儿童的4种血清标志物浓度均高于健康对照组(P<0.01).在中度、重度及肝硬化儿童中,有两种或3种以上的标志物显著性增加.结论 4项标志物在儿童期有其年龄特征.它们可反映慢性肝炎患儿肝纤维化的严重程度.     

Serum procollagen type III peptide in chronic hepatitis B

The clinical significance of serum procollagen type III peptide, a marker of active fibrogenesis, was evaluated in 110 hepatitis B surface antigen positive patients with chronic hepatitis (32 chronic persistent hepatitis, 60 chronic active hepatitis, and 18 active cirrhosis), selected on the basis of active viral replication and biochemical activity, including 54 cases treated with interferon-α. At presentation the procollagen type III peptide level serum was above normal in 48 (44%) of the 110 patients and the median value was significantly higher than that of healthy carriers with normal transaminases and histology (P<0.000005). Semiquantitative histological evaluation showed a significant correlation between serum procollagen type III peptide levels and necrosis/inflammation in the subgroup of patients with chronic active hepatitis, but no relationship with the score of fibrosis. Among patients treated with interferon-α and with increased fibrogenic activity (indicated by high pretreatment serum levels of procollagen type III peptide), peptide levels were significantly decreased when pretreatment levels were compared with those at 12 months after therapy withdrawal, both in responders to interferon (P=0.022) and non-responders (P=0.012). However, serum procollagen type III peptide levels normalized in 75% of responders to interferon with sustained serological and histological remission of liver disease, but in only 21% of non-responders (P=0.02). These results obtained in a well-defined population suggest that serum procollage type III peptide is a better marker of active fibrogenesis and inflammation than an indicator of the extent of fibrosis, and that interferon may reduce active liver fibrogenesis in chronic hepatitis B indenpendently of its effect on viral replication. However, a consistent proportion (56%) of our chronic hepatitis B patients had normal serum procollagen type III peptide levels at presentation, thus precluding the clinical use of this marker both for diagnosis of liver injury and for monitoring the therapeutic response to interferon.     

Fibrotic process and drug metabolism in alcoholic liver disease

The effect of fibrosis on drug metabolism in alcoholic liver disease was evaluated in a comparison of the concentrations of serum aminoterminal propeptide of type III procollagen and basement membrane (BM; 7S domain of type IV collagen and laminin) antigens with in vitro (cytochrome P-450) and in vivo (antipyrine) drug metabolism in 67 alcoholics classified by liver histology. Alcoholics with intact or fatty liver had rapid or normal drug metabolism and normal collagen metabolism. Alcoholics with a fatty liver plus fibrosis or active cirrhosis had reduced drug metabolism and elevated levels of serum markers for collagen and BM metabolism. Alcoholics with inactive cirrhosis who had received therapy with enzyme inducers had a tendency toward normal drug and collagen metabolism parameters. Antipyrine metabolism, but not P-450 content, was related to the levels of serum type III collagen and BM markers. The fibrotic process, especially BM formation, creates a mechanical barrier that may prevent contact between blood and hepatocytes, thus delaying substrate availability.     

Increased myocardial collagen turnover in patients with progressive cardiac conduction disease

Background: Histopathologically, progressive cardiac conduction disease (PCCD) is characterized by progressive fibrosis and sclerodegenerative changes in the proximal and distal conduction system of the heart. Therefore, we sought to determine the serum levels of myocardial collagen turnover markers, extracellular matrix components, transforming growth factor β₁ (TGFβ₁), and bone morphogenic protein‐7 (BMP‐7) in this population. Methods: Study population included 20 patients (6 M/14 F, mean age 76 ± 8 years) with acquired, permanent 2:1, or complete atrioventricular block and compared with age‐ and sex‐matched, asymptomatic, healthy control subjects (n = 18, 6 M/12 F, mean age 75 ± 7 years). Serum myocardial collagen turnover markers:matrix metalloproteinases (MMP‐1, 2, 9), tissue inhibitor of matrix metalloproteinase (TIMP‐1), amino‐terminal propeptide of procollagen type I (PINP) and type III (PIIINP), carboxy‐terminal telopeptide of collagen type I (CITP), and carboxy‐terminal propeptide of procollagen type I (PICP), serum extracellular matrix components (laminin and fibronectin), TGFβ₁, and BMP‐7 levels were measured in both groups. Results: Serum PICP (849 ± 396 vs 631 ± 294 ng/mL, P = 0.04), PIIINP (3.7 ± 1.3 vs 3 ± 1 μg/L, P = 0.03), CITP (0.68 ± 0.35 vs 0.48 ± 0.25 ng/mL, P = 0.037), and plasma MMP‐9 (58.8 ± 56 vs 25.9 ± 17.3 ng/mL, P = 0.006) levels were higher in patient population compared to control subjects. Serum MMP‐1 (24.1 ± 20.5 vs 13.6 ± 7.5 ng/mL, P = 0.045) and MMP‐2 (1310 ± 139 vs 1186 ± 163 ng/mL, P = 0.01) levels were higher in control subjects compared to patient population. There was no difference in serum TIMP‐1, PINP, laminin, fibronectin, TGFβ₁, and BMP‐7 levels between two groups. Conclusion: Our findings demonstrate the presence of increased myocardial collagen turnover and active fibrotic process in patients with PCCD compared to control subjects.     

Serum type III procollagen peptide levels in coronary artery disease (a marker of atherosclerosis)

The known shift in collagen synthesis from procollagen type I to type III in patients with atherosclerosis, suggested measurement of serum procollagen III peptide (PIIIP) levels in patients with coronary artery disease (CAD). Two groups of patients were studied: group I--thirty-six patients with CAD (male, mean age 56.9 +/- 7.5 years, hospitalized for coronary angiography. Risk factors included 16 patients with high blood pressure, four diabetics, 31 smokers and 15 with hypercholesterolaemia. Five patients had no significant lesions, seven had one vessel with over 50% stenosis, 10 had two vessels and 14 had three vessels. Group II--35 patients (male, mean age 39.4 +/- 13.3 years), with normal physical examination and ECG according to WHO criteria, formed the control group: the risk factors included nine patients with high blood pressure, 14 smokers and one with hypercholesterolaemia. Procollagen III peptide levels were determined by radioimmunoassay. In group I, PIIIP levels were 26.8 +/- 16 ng ml-1 vs. 10.4 +/- 3.2 for group II. Sixty-one per cent of group I had pathological levels of PIIIP with an absence of correlation with the severity of atherosclerosis or risk factors. Only 2.8% of patients in group II had pathological levels. Procollagen III peptide determination would appear to be a sensitive, specific and predictive test for atherosclerosis in patients with CAD.     

血清结缔组织生长因子对慢性肝病的诊断价值

目的观察肝病患者血清结缔组织生长因子(CTGF)变化,探讨其与肝纤维化形成的关系,寻找新的判定肝纤维化程度的指标。方法应用ELISA法测定313例肝病患者血清CTGF水平,用RIA法测定血清透明质酸、Ⅲ型前胶原蛋白、Ⅳ型胶原蛋白、层粘连蛋白。对其中45例慢性肝病患者进行肝穿刺组织病理学诊断,应用SPSS11.0统计软件分析CTGF等指标与肝纤维化分期的关系。结果血清CTGF的水平与慢性肝炎病情轻重程度有关,与肝组织病理学纤维化分期呈正相关,r=0.634。结论血清CTGF与肝纤维化的形成有密切关系,是评估肝纤维化程度(分期)的良好指标。     

Biochemical markers of hepatic fibrosis.

Most liver diseases lead to a pathobiochemical reaction termed liver fibrosis. This is a dynamic process implying different rates of progression or regression. Thus, histological examination of a liver biopsy is essential for a diagnosis but biochemical tests are necessary for assessing the activity of the process and monitoring its evolution. We review the most important constituents of liver connective tissue and the biochemical tests developed for evaluating liver fibrosis. The aminopeptide of type III procollagen is the most widely used parameter: two different radioimmunoassays have been developed with different affinities for the two circulating forms of the molecule. The determination of serum P3P reveals an elevation of blood levels both in acute and chronic liver diseases. In the first, serum P3P is an index of hepatic necrosis and inflammation which correlates with other biochemical parameters. In the second it is an index of active fibrogenesis. Moreover, in primary biliary cirrhosis this parameter is an independent prognostic variable and an important predictor of survival. Other immunoassays exist for different collagen cleavage products, but their clinical value is not established. Laminin and fibronectin are the principal structural glycoproteins in liver. Fibronectin determination does not seem to be of clinical value in liver disease. In contrast, serum laminin correlates with the severity of portal venous pressure in advanced liver disease. Its concentration parallels the severity of varices and may indicate the risk of bleeding. Hyaluronate is a high molecular weight polysaccharide, raised serum concentrations reflect both its increased synthesis by activated fibroblasts and its impaired catabolism by the liver. Thus, it may be useful for evaluating and monitoring the progression of chronic liver disease. The measurement of the activity of prolyl 4-hydroxylase as well as that of lysine oxidase and other enzymes has been proposed, but their clinical value is not sufficiently demonstrated. A panel of tests (e.g., laminin, hyaluronate and the aminopeptide of type III procollagen) seems to be recommended for a biochemical assessment of liver fibrosis in clinical practice.     

Three serum markers of collagen biosynthesis in Nigerians with cirrhosis and various infectious diseases

Serum immunoreactive prolyl hydroxylase protein, galactosylhydroxylysyl glucosyltransferase activity, and the aminoterminal propeptide of type III procollagen (S-Pro(III)-N-P) were measured in twenty patients with cirrhosis and ninety with various infectious diseases, and the values were compared with those in sixty apparently healthy Nigerians. The means for all three markers were elevated significantly in the patients with cirrhosis (P less than 0.001), acute viral hepatitis (P less than 0.001), amoebic liver abscess (P less than 0.001) and the early stages of Schistosoma mansoni infection (P less than 0.001 for S-Pro(III)-N-P, P less than 0.005 for the two other markers). The mean S-Pro(III)-N-P was also distinctly elevated during the early stages of Schistosoma haematobium infection (P less than 0.01) and filariasis (P less than 0.001), whereas none of the three markers was elevated during an acute attack of malaria. Significant correlations were found between the values for the three markers within the groups of patients with cirrhosis, amoebic liver abscess and schistosomiasis, the correlations for the pooled group of all patients being highly significant (P less than 0.001). The data suggest that elevated hepatic collagen formation is found not only in cirrhosis but also in several infectious diseases. The three serum markers may be useful for showing the stages of active collagen formation in various liver diseases and for predicting the development of fibrosis in acute cases if the values remain elevated.