Hepatic extraction of the aminoterminal propeptide of type III procollagen before and after bile duct ligation in pigs

The aminoterminal propeptide of type III procollagen is extracted from the circulation by the liver, and PIIINP is found in bile. This study was performed in order to investigate whether biliary excretion contributes substantially to the hepatic extraction of circulating PIIINP. Hepatic extraction before and during a 4-h period after ligation of the common bile duct was assessed from serum PIIINP concentrations in a systemic artery, the portal vein and a hepatic vein of seven healthy anaesthetized pigs. Seven sham-operated anaesthetized pigs served as controls. Ligation of the bile duct did not cause a decrease in the hepatic extraction ratio of circulating PIIINP. The PIIINP serum levels of the cholestatic pigs and of the controls were similar throughout the investigation period. The PIIINP concentrations in bile were only 10% of the corresponding serum values. Gel filtration of sera showed that the lower PIIINP concentration in the hepatic vein, as compared to the artery and the portal vein was due to a selective decrease in the concentration of the intact propeptide. The study shows that biliary excretion does not contribute significantly to the hepatic extraction of circulating PIIINP in the normal liver. Furthermore, the hepatic extraction of circulating PIIINP preferentially affects the intact propeptide, rather than the somewhat larger PIIINP related molecule in serum.     

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)     

Effect of insulin on serum amino-terminal propeptide of type III procollagen in non-insulin-dependent diabetes mellitus.

The effect of insulin on the serum levels of the amino-terminal propeptide of type III procollagen (PIIINP) was investigated in patients with non-insulin-dependent diabetes mellitus, whose disease was unsatisfactorily controlled by oral drugs. Before insulin therapy the PIIINP values of the patients (3.2 +/- 1.3 micrograms/l, n = 38) varied within the range of healthy subjects (3.1 +/- 0.6 micrograms/l, n = 50, NS). Insulin therapy (6-20 IU at bedtime plus the oral drugs) improved the glycemic control and increased the serum PIIINP during a 4 week (3.1 +/- 0.9 to 3.8 +/- 1.1 micrograms/l, P less than 0.01, n = 8) and an 8 week period (3.2 +/- 1.3 to 3.8 +/- 1.6 micrograms/l, P less than 0.001, n = 22). The values were still elevated after 6 months on insulin (3.5 +/- 1.5 to 4.0 +/- 1.7 micrograms/l, P less than 0.01, n = 12). Placebo-insulin did not alter the concentration of PIIINP (3.1 +/- 0.6 to 2.8 +/- 0.6 micrograms/l, NS, n = 8) whereas the glycemic control improved and body weight decreased. The PIIINP values correlated with fasting insulin before (r = 0.403, P less than 0.05, n = 30) and after the therapy (r = 0.452, P less than 0.001, n = 60). Insulin therapy, while correcting the hormone deficiency and restoring glucose and protein metabolism, seems to activate the synthesis of type III procollagen in patients with NIDDM. This may promote the atherosclerotic process.     

Serum concentrations of aminoterminal propeptide of type III procollagen and propeptide of human type I procollagen in systemic lupus erythematosus

The purpose of this study was to assess the association between the serum levels of aminoterminal propeptide of type III procollagen (PIIINP) and carboxyterminal propeptide of type I procollagen (PICP) with disease activity and damage in systemic lupus erythematosus (SLE). Thirty-three patients with SLE were compared with 31 controls. The assessment in SLE included disease activity indices (SLEDAI, MEX-SLEDAI) and damage index (SLICC/ACR). PIIINP and PICP were measured by radioimmunoassay. Compared with controls, mean levels of PIIINP were higher in SLE (2.9±1.8 vs. 1.8±1.2, P=0.006). PICP was also increased in SLE versus controls (163±94 vs. 102±62, P=0.007). PIIINP was correlated with SLICC/ACR (r=0.33, P=0.048). No correlation was observed between PICP and PIIINP with other clinical or therapeutic variables. These preliminary data suggests a role of PIIINP as a marker for chronic damage. Follow-up studies are required to evaluate its utility in predicting future damage.     

Serum type III procollagen propeptide levels in acromegalic patients

Serum type III procollagen propeptide (PIIIP) is a reliable index of tissue collagen synthesis. Since in acromegaly there is increased collagen production, we measured serum PIIIP in acromegalic patients before any treatment (basal), during medical treatment with the somatostatin analog SMS 201-995, and after pituitary adenomectomy. In all patients, serum GH and plasma somatomedin-C (SmC) levels were also measured. Basal serum PIIIP levels were significantly (P less than 0.01) higher in acromegalic patients (mean +/- SEM, 22.7 +/- 2.1 ng/ml) than in normal subjects (n = 30; 9.7 +/- 0.5 ng/ml), and they were significantly correlated with plasma SmC values (r = 0.31; P less than 0.05). A significant (P less than 0.01) reduction in PIIIP levels occurred in patients treated with SMS 201-995 or surgery (from 24.3 +/- 2.7 to 12.4 +/- 1 ng/ml) as well as in GH and SmC levels. The maximum percent decrease in serum PIIIP was significantly correlated with those in GH (r = 0.65; P less than 0.01) and SmC (r = 0.60; P less than 0.01). Serum PIIIP levels did not change in those patients in whom neither GH nor SmC were decreased by treatment. In conclusion, serum PIIIP levels are elevated in acromegalic patients, and they decline in parallel with GH and SmC during medical or surgical treatment. Serum PIIIP measurements may be useful in the evaluation of acromegalic patients to gain information on the biological activity of GH and in monitoring the course of the disease.     

Aminoterminal propeptide of type III procollagen in serum in alcoholic liver disease

An assay of serum antigens related to the aminoterminal propeptide of type III procollagen has been suggested for monitoring fibrotic processes in the liver. These antigens were measured here in 61 alcoholics who were divided into four groups on the basis of liver histology: normal light microscopy, fatty liver, alcoholic cirrhosis with hepatitis, and inactive cirrhosis. All the subjects having alcoholic hepatitis with cirrhosis had elevated values in the assay, whereas some of those with either fatty liver or inactive cirrhosis still had normal values. It was, therefore, not possible on the basis of this method alone to distinguish fatty liver from cirrhosis or alcoholic hepatitis, although very high values were suggestive of alcoholic hepatitis. In a follow-up study, the aminopropeptide value decreased slowly during recovery from alcoholic hepatitis and increased rapidly after a new drinking bout. The antigens detected by the assay are heterogeneous in human serum. The proportions of the three main peptide forms varied during recovery from alcoholic hepatitis, the authentic propeptide being the main one at the acute stage, but almost disappearing later. The usefulness of the assay could probably be improved if distinct assays were available for the different antigen forms.     

Serum levels of the aminoterminal propeptide of type III procollagen and hyaluronan during resolving and nonresolving posttransfusion non-A, non-B hepatitis

Serum levels of the aminoterminal propeptide of type III procollagen (PIIINP) and hyaluronan were analysed before and during the acute, recovery and chronic phases of non-A, non-B (NANB) posttransfusion hepatitis (PTH) in 13 patients. All patients were discovered during a prospective study on NANB PTH in patients undergoing open-heart surgery. 7/13 (54%) patients resolved their hepatitis within 6 months after onset, whereas 6/13 (46%) went on to chronic hepatitis. In 5 of these 6 patients a liver biopsy during the chronic phase of the hepatitis showed chronic active hepatitis in 2 and chronic persistent hepatitis in 3. During the acute NANB PTH phase the mean serum PIINP level rose significantly as compared to prehepatitis levels and to levels in a reference group not developing hepatitis. Neither PIIINP levels nor hyaluronan levels, however, could differentiate patients with resolving from patients with nonresolving hepatitis. These markers should, however, be further evaluated as potential markers for development of fibrosis/cirrhosis during chronic hepatitis.     

Aminoterminal propeptide of type III procollagen and hyaluronan in patients with primary biliary cirrhosis: Markers of fibrosis in primary biliary cirrhosis

The aminoterminal propeptide of type III procollagen (PIIINP) and hyaluronan have previously been studied in different liver diseases. The results of these studies are controversial. The aim of the present study was to examine the relationship between PIIINP and hyaluronan levels and the clinical, biochemical and histological features of primary biliary cirrhosis (PBC) and its prognosis. Fifty-five PBC patients were studied at the time of diagnosis of PBC and were followed up for a mean of 58 months. During the follow-up period 21 patients died. In addition, 30 healthy subjects were examined in the present study. Hyaluronan and PIIINP were measured by radioimmunoassay and the levels of both PIIINP and hyaluronan were higher in PBC patients than in healthy volunteers (P< 1.8 times 10^-6 and 1.6 times 10^-9, respectively). Hyaluronan and PIIINP levels were above normal values in 82 and 84% of PBC patients, respectively. There were correlations between PIIINP and hyaluronan and the histological stage of PBC (r=0.44, P< 0.004 and r=0.56, P< 0.00001, respectively). The correlation between PIIINP and hyaluronan was 0.46 (P< 0.0035). In symptomatic patients, both PIIINP and hyaluronan values were higher than in controls (P< 0.002 and P< 0.006, respectively). The levels of PIIINP correlated significantly with bilirubin (r=0.43, P< 0.006), while hyaluronan was correlated with age (r=0.33, P< 0.015), pruritus (r=0.32, P< 0.02), fatigue (r=0.41, P< 0.003), hepatomegaly (r=-0.46, P< 0.0008), the presence of oesophageal varices (r=0.34, P< 0.002), weight loss (r=0.29, P< 0.05), bilirubin (r=0.54, P< 0.0001), albumin (r=-0.30, P< 0.04), extent of fat excretion (r=0.53, P< 0.009) and length of symptomatic period before diagnosis of PBC (r=0.43, P< 0.002). Using Cox's logistic regression analysis, survival was found to be influenced by bilirubin concentration but not by hyaluronan, PIIINP, age, albumin or histological stage. Therefore, hyaluronan is a more sensitive marker for predicting advanced PBC than is PIIINP. However, neither hyaluronan nor PIIINP gave any indication of prognostic outcome.     

Independent and additional prognostic value of aminoterminal propeptide of type III procollagen circulating levels in patients with chronic heart failure

BACKGROUND: In chronic heart failure (CHF), changes in the extracellular space contribute to cardiac dysfunction. We aimed to determine whether aminoterminal-propeptide of type III procollagen (PIIINP), a marker of extracellular matrix turnover, might provide prognostic information in CHF patients. METHODS AND RESULTS: A total of 101 consecutive CHF patients (mean age 61.7 +/- 8.7 years, 88% males) were followed up between 1999 and 2001. The combined endpoint of the study was death and hospitalization for heart failure. During follow-up there were 15 deaths and 11 hospitalizations for worsening heart failure. At the survival analysis, age (P = .02), New York Heart Association class (P = .014), s-creatinine (P = .014), plasma-PIIINP (p-PIIINP) levels (P = .005), left ventricular ejection fraction (LVEF) (P = .0002), and a restrictive mitral filling pattern (P = .0003) predicted event-free survival. At the multivariate analysis, p-PIIINP levels predicted outcome independently of other clinical variables, hormones, and echocardiographic and exercise testing variables (P < .05 in all models). In patients with LVEF <31%, the presence of p-PIIINP >4.7 microg/L levels was significantly associated with a higher risk of death and hospitalization as compared with the other patients (event-free survival rate at 12 months: 45% versus 95%; at 24 months: 27% versus 88%; at 36 months: 18% versus 85%, P < .0001). CONCLUSIONS: In patients with CHF, PIIINP levels predict outcome independently of clinical status, hemodynamics and hormonal activation. PIIINP levels provide additional prognostic information to that of left ventricular function alone, suggesting that it may reflect more than cardiac extracellular matrix turnover.     

充血性心力衰竭患者血清Ⅰ型前胶原羧基端肽及Ⅲ型前胶原氨基端肽的变化

目的 :研究充血性心力衰竭 (CHF)患者血清Ⅰ型前胶原羧基端肽 (PIP)和Ⅲ型前胶原氨基端肽 (PⅢP)含量变化及与反映左室结构和功能的参数间的关系。方法 :应用放射免疫法测定 2 0例正常人 (对照组 )和 6 1例CHF患者 (CHF组 )血清中PIP和PⅢP浓度 ,用M型超声心动图测算左室重量指数 (LVMI)和左室射血分数(LVEF) ,多普勒超声心动图测定二尖瓣口舒张早期和晚期最大血流速度 (VE和VA)。结果 :CHF组血清中PIP和PⅢP含量较对照组明显升高 ,并随着心功能等级的增加而有升高趋势 ,但与导致心力衰竭的基础病因无关。血清PⅢP和PIP水平与LVMI呈正相关 ,与VE/VA 呈负相关 ,并与同期测定的血浆血管紧张素Ⅱ和醛固酮含量有一定相关性。结论 :CHF患者血清PIP和PⅢP水平显著升高可以反映其左室重构过程中细胞外基质的代谢变化     

Serum hyaluronan and aminoterminal propeptide of type III procollagen in primary biliary cirrhosis: relation to clinical symptoms, liver histopathology and outcome.

Hyaluronan (HA) and aminoterminal propeptide of type III procollagen (PIIINP), two biochemical connective tissue markers, were determined in 76 patients with primary biliary cirrhosis (PBC). The HA and PIIINP concentrations were significantly increased compared with controls (P less than 0.001). Both HA and PIIINP levels correlated significantly with conventional liver-function tests. All patients with stage IV PBC showed increased concentrations of both these variables. However, HA was a better marker with regard to prediction of development of cirrhosis as well as prediction of symptoms. Furthermore, HA also showed a negative correlation with time of survival (P less than 0.05). The present data indicate that HA is a more sensitive marker of liver damage in PBC than PIIINP.     

Is measurement of type III procollagen amino propeptide useful in primary biliary cirrhosis?

We have examined the value of serum type III procollagen amino propeptide (PIIINP) measurement both in evaluation of disease activity and in estimation of prognosis in primary biliary cirrhosis (PBC). 55 paired sera from 32 PBC patients not receiving treatment known to affect PIIINP levels not with non-hepatic inflammatory conditions were used to estimate serum PIIINP by radioimmunoassay. Significant correlations were found between serum PIIINP and serum albumin (P less than 0.001), bilirubin (P less than 0.002) and aspartate transaminase (P = 0.01). The mean serum PIIINP level rose with advancing histological stage (P less than 0.001). In 18 patients in whom more than 1 serum was assayed (mean follow-up 42 months) PIIINP often fell, particularly in patients with established cirrhosis and advanced disease. The independent prognostic value of PIIINP was examined using Cox's proportional hazards model with three other prognostic co-variables (bilirubin, albumin, patient age). Stepwise regression analysis selected albumin (P less than 0.001) and bilirubin (P = 0.002) as the most important prognostic factors. PIIINP did not give independent prognostic information. We conclude that PIIINP is another marker of disease activity in PBC which confers no benefit over existing conventional measurements in routine management of this disease.     

Serum aminoterminal propeptide of type III procollagen after cardiac transplantation and the effect of rejection

The present study examines serum concentrations of the aminoterminal propeptide of type III procollagen (S-PIIINP), a marker of type III collagen synthesis, after heart transplantation, and assesses changes induced by rejection. Fourteen transplant patients were included with 12 coronary artery bypass patients serving as controls. Mild to moderate rejection was found in 44 biopsies, and severe rejection in 6. Two severe rejection incidents occurred before postoperative day 10, the remainder at postoperative days 23 to 57. S-PIIINP was elevated in transplant patients at postoperative days 1 to 7 (p ≤ 0.01), with return to baseline at postoperative day 60 (p = 0.14, N = 6). S-PIIINP remained unchanged after mild to moderate rejection, but increased 1 to 2 weeks following severe rejection occurring after postoperative day 10. S-PIIINP was elevated in bypass patients from postoperative day 2 throughout the study period of 360 days (p ≤ 0.01). Thus, type III collagen turnover after heart transplant and coronary artery bypass grafting resembles wound healing. Collagen synthesis after severe rejection is reflected by SP-IIINP approximately 2 weeks after transplant. The findings may prove to be significant concerning the prognosis of heart transplant patients.     

Is the aminoterminal propeptide of type III procollagen degraded in the liver? A study of type III procollagen peptide in serum during liver transplantation in pigs

The aminoterminal propeptide of type III collagen was monitored in serum during liver transplantation in nine pigs. The aim was to investigate whether removal of the liver causes any changes in the serum concentration of the propeptide. Another connective tissue component, hyaluronan, a glycosaminoglycan known to be degraded in the liver endothelial cells, was also measured. Removal of the liver caused a significant increase in the concentration of the intact propeptide as well as of hyaluronan. Gel filtration confirmed the increase in the amount of intact propeptide. However, another large propeptide-related antigen, eluted near the void volume, appeared in the antigen profile during the anhepatic phase. This peak probably represents the propeptide still attached to the collagen molecule (pN collagen). The findings indicate that the liver is involved in the degradation of the propeptide and of larger propeptide-holding proteins.     

Serum amino-terminal propeptide of type III procollagen and 7S domain of type IV collagen correlate with hepatic iron concentration in patients with chronic hepatitis C following alpha-interferon therapy

BACKGROUND: It has been reported that chronic infection with hepatitis C virus is associated with excess iron deposits in the liver of subjects who are neither alcoholics nor recipients of blood transfusions. However, little is known about the relationship between hepatic iron concentration (HIC) and the serum levels of hepatic fibrogenesis markers, which were caused by interferon therapy for chronic hepatitis C. Therefore, changes in the serum amino-terminal propeptide of type III procollagen (P-III-P) and the 7S domain of type IV collagen (7S-IV) in 16 patients treated with alpha-interferon (IFN-alpha) were studied, and their HIC and histological assessment evaluated. Hepatic iron concentrations were measured by using liver biopsy specimens obtained before and 6 months after the cessation of treatment. METHODS AND RESULTS: Eight subjects (50%) who had normal alanine transaminase levels at 6 months after therapy showed significantly lowered HIC, and attenuated hepatic iron staining with decreased serum levels of P-III-P and 7S-IV compared to the remaining subjects. The HIC was significantly correlated with the serum levels of P-III-P and 7S-IV in all subjects. CONCLUSIONS: These findings suggest that IFN-alpha treatment may decrease stimuli for fibrogenesis, at least in part, by reducing the hepatic iron deposition in patients with chronic hepatitis C.