Serum procollagen type III peptide levels in patients with acute viral hepatitis

Evaluation of liver fibrosis: a concise review

The diagnosis of liver fibrosis has traditionally relied on liver biopsy. However, recent studies have suggested that there can be up to a 33 % error in the diagnosis of cirrhosis. In this article, we review the current status of liver biopsy as a gold standard for the diagnosis of liver fibrosis and discuss the radiological and serum tests that have been proposed as potential adjuncts or alternatives to biopsies. Indirect markers of liver fibrosis which reflect alterations in liver function and or inflammation are discussed as well as more direct markers of liver fibrosis. The limitations of utilization of these markers for both cross-sectional diagnosis of fibrosis and monitoring disease progression or regression are discussed.

Beneficial effects of pentoxifylline on cyclosporine-induced nephrotoxicity

1. Hypertension and renal failure are the two most common and severe complications due to cyclosporine A (CsA) therapy after transplantation. To determine whether an in vivo treatment with pentoxifylline (PTX) can prevent the toxic effects of CsA, three groups of rats were studied. 2. The first group of rats (n = 11) received daily injections of CsA (15 mg/kg, i.m.) and PTX (45 mg/kg, i.p., b.i.d.), the second group of rats (n = 11) was treated with CsA only and the third group of rats (n = 11) served as the control group (vehicle treatment). 3. Whole blood CsA levels were similar in CsA + PTX and CsA alone groups. Although CsA treatment significantly increased mean arterial blood pressure (110.00 +/- 2.48 mmHg; P < 0.01), there was no significant increase in the PTX co-treated group (104.09 +/- 2.96 mmHg) compared with initial values. In both the CsA alone and CsA + PTX groups the heart rate (365.45 +/- 6.65 and 357.27 +/- 7.23 b.p.m., respectively; P < 0.05) were found to be significantly higher than initial values. Serum creatinine levels increased significantly in the CsA alone group (1.40 +/- 0.11 mg/dL; P < 0.01) compared with control values (0.81 +/- 0.04 mg/dL). This increase was prevented by co-treatment with PTX (serum creatinine 1.11 +/- 0.01 mg/dL; P < 0.05). Total [99mTc]-DTPA percentage renal uptake, as an index of glomerular filtration rate (GFR), was markedly and significantly lower in the CsA alone group (10.01 +/- 0.79%; P < 0.01) than in the control group (18.19 +/- 1.32%). Pentoxifylline co-treatment attenuated this decrease compared with GFR in the CsA alone group (13.00 +/- 0.75%; P < 0.01). 4. These results suggest that the co-administration of PTX with CsA may prevent the dose-limiting toxic effects of CsA therapy.

Serum hyaluronan and aminoterminal propeptide of type III procollagen: variation with age

The serum levels of hyaluronan and the aminoterminal propeptide of Type III procollagen (PIIINP) were compared in 585 healthy individuals as a function of age. Newborn children displayed high hyaluronan (695 +/- 634 micrograms l-1, mean +/- SD) and PIIINP (295 +/- 152 micrograms l-1) values. The values were not correlated to the gestational week in which the children were born or to the birth weight but there was a significant correlation (p < 0.05) between the hyaluronan and PIIINP levels. During the first year the levels dropped and in childhood (1-16 years of age) both hyaluronan and PIIINP levels were fairly constant at 27 +/- 16 and 22 +/- 8.4 micrograms l-1, respectively. The PIIINP level showed a marked drop in adults compared to children. The drop continued to about 50 years of age (6.5 +/- 2.2 micrograms l-1) and then there was a slight increase in elderly people. The hyaluronan showed a continued increase with age from the level at 16 years of 29 +/- 17 micrograms l-1 to a mean value of 177 +/- 133 micrograms l-1 in people over 75 years. There was no increase in serum hyaluronan in women during pregnancy but the PIINP level increased in the later part of the gestational period. There was no correlation between the serum values of hyaluronan and PIIINP when compared throughout the life span which indicates that the blood levels of the two markers are regulated by independent factors.

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.