Application of markers of collagen metabolism in serum and synovial fluid for assessment of disease process in patients with rheumatoid arthritis.

OBJECTIVE--To assess the potential of markers of collagen metabolism to reflect disease processes in rheumatoid arthritis (RA). METHODS--Serum (S) and synovial fluid (SF) from 59 patients with RA, and a knee joint effusion and serum from 90 control subjects were studied with radioimmunoassays for the aminoterminal propeptides of type I and type III procollagens (PINP and PIIINP, respectively). The breakdown of type I collagen was quantified with a radioimmunoassay for the cross linked carboxyterminal telopeptide of type I collagen (ICTP). RESULTS--About 50% of the patients had increased S-ICTP and S-PIIINP values, whereas S-PINP was increased in only 20% of the patients. The mean SF:S ratios of these markers varied between 4 (for ICTP) and 340 (for PIIINP), indicating that markers of collagen metabolism are formed locally and then released into the circulation. SF-PINP and SF-PIIINP correlated with each other (rs = 0.86, p < 0.001) and with SF-ICTP (rs = 0.69, p < 0.001, and rs = 0.65, p < 0.001, respectively). SF-ICTP was clearly related to radiographic findings in the corresponding knee joint, patients with gross bone deformation having the greatest SF-ICTP concentrations. S-ICTP and S-PIIINP also correlated with conventional markers of disease activity, such as C reactive protein and joint swelling score. CONCLUSION--Markers of collagen metabolism both in serum and synovial fluid can be measured to provide an assessment of disease process in patients with RA. ICTP and PIIINP are the most informative.     

Serum aminoterminal type III procollagen peptide in early rheumatoid arthritis: relation to disease activity and progression of joint damage

Serum levels of the aminoterminal type III procollagen peptide (S-PIIINP) have been used as markers of proliferative inflammation in rheumatoid arthritis (RA) and a prognostic significance has been suggested. To test this further we have measured S-PIIINP longitudinally for 2 years in 66 patients with definite RA and a disease duration of less than 2 years, and related the levels to clinical, biochemical, and radiographic findings. In this patient group the correlations between S-PIIINP and ESR and CRP, respectively, were higher than those obtained between S-PIIINP and articular indices, and markedly higher than in patients with RA of longer duration. Patients with normal mean levels of S-PIIINP during the study period had a significantly slower rate of radiographic progression than patients with elevated mean levels of S-PIIINP. ESR yielded in general higher correlations with the joint damage process than did S-PIIINP. The correlations between S-PIIINP and the joint damage scores increased with time. A multiple regression analysis showed that ESR explained most of the variance in joint damage progression over 2 years, but S-PIIINP added independent information. About one third of the variance could be explained by the two variables.     

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.     

Markers of collagen and basement membrane metabolism in sera of patients with progressive systemic sclerosis.

The concentrations of the amino terminal propeptide of type III procollagen, the 7S domain of type IV collagen, and the fragment P1 of laminin (PIIINP, 7S, and P1 respectively) and the activity of galactosylhydroxylysyl glucosyltransferase (GGT) in serum were evaluated as indicators of disease activity in a cross sectional study of 84 patients with progressive systemic sclerosis. The mean values of PIIINP, P1, and GGT were raised in progressive systemic sclerosis, 19-32% of patients having abnormal values of the various tests. PIIINP, measured with two different assays, and P1 were associated with active, acute, or subacute disease. GGT also correlated positively with some acute phase proteins in the whole group, without a clear association with the course of the disease. Arthritis was associated with increased PIIINP concentrations as well as with an increased activity of GGT. Kidney disease led to raised concentrations of the degradation products of PIIINP. Raynaud's phenomenon in the hands was related to increased PIIINP concentrations.     

Elevated serum PIIINP and laminin in inflammatory bowel disease indicate hepatobiliary and pancreatic dysfunction

BACKGROUND/AIMS: Levels of S-PIIINP (serum aminoterminal propeptide of type III procollagen) have been shown to be increased in patients with primary sclerosing cholangitis and inflammatory bowel disease. The aim of the study was to investigate the serum concentrations of PIIINP and laminin in inflammatory bowel disease patients, their relationship with inflammatory bowel disease-associated hepatobiliary and pancreatic dysfunction, and to correlate them with clinical, endoscopic, and histologic variables. METHODOLOGY: S-PIIINP and S-laminin were measured in 222 consecutive inflammatory bowel disease patients, who were screened for abnormal liver and pancreatic enzymes and for pancreatic exocrine hypofunction with the p-aminobenzoic acid test (215 patients). The patients with abnormal screening results were further scheduled for endoscopic retrograde cholangiopancreatography, liver biopsy, secretin test and ultrasound. RESULTS: S-PIIINP and S-laminin were abnormally high in 19% and 40% of all inflammatory bowel disease patients, respectively. The elevated levels of the fibrosis markers were associated with laboratory signs of either hepatobiliary or pancreatic disease. Hepatobiliary disease was found in 37 (17%) of inflammatory bowel disease patients, 15 of whom had primary sclerosing cholangitis. The median levels of S-PIIINP and S-laminin were significantly higher in patients with hepatobiliary disease than in those without (P < 0.0001 and P < 0.001, respectively), being most strikingly elevated in primary sclerosing cholangitis. Abnormal pancreatic screening tests were found in 67 (30%) patients. High levels of S-PIIINP and S-laminin were also significantly associated with low values in p-aminobenzoic acid (P < 0.001 and P < 0.005) and secretin (P < 0.01 and P < 0.05) tests, but not with inflammatory bowel disease category, endoscopic or histological disease extent, frequency of bowel resection or actual clinical activity. CONCLUSIONS: In inflammatory bowel disease, increased S-PIIINP and S-laminin are associated with hepatobiliary and pancreatic disorders.     

Bone marrow fibrosis and disease activity in multiple myeloma monitored by the aminoterminal propeptide of procollagen III in serum

Simple bone marrow fibrosis is seen in 10–30% of multiple myeloma (MM) patients. We investigated the incidence and characteristics of the bone marrow stromal alterations, in order to characterize the collagens involved by immunohistochemistry, and to evaluate the use of serum aminoterminal propeptide of type III procollagen (PIIINP) as a marker of marrow fibrogenesis and disease activity in MM. 34 consecutive patients with newly diagnosed MM were included prospectively, and followed for 12–30 months. Compared with the findings in 15 normal individuals we found increased interstitial deposits of collagen III in 48% of MM patients, whereas deposits of collagen I were not increased. Interstitial fibrosis appeared to be restricted to areas of severe plasma cell infiltration, but it could also have a more dispersed presentation in the severely infiltrated marrow. There was a high co-distribution of collagen III fibrils and reticulin fibres. Serum PIIINP levels were elevated in most patients, and in the follow-up study serum PIIINP showed a good correlation with the response to treatment. Patients with resistant or progressive disease had continually elevated levels of PIIINP. In most patients with responsive disease serum PIIINP normalized, and we observed no relapses in patients who had normal serum PIIINP levels. Other patients who responded to treatment by reduced M-component level, but had persistently elevated serum levels of PIIINP, had either early relapses or developed progression of osteolytic lesions in spite of unchanged M-component levels. Therefore an elevated serum PIIINP during treatment might indicate an active malignant clone. Serum PIIINP does not simply follow the M-component, but gives further information of potential therapeutic value.     

Synovial fluid and serum concentrations of aminoterminal propeptide of type III procollagen in healthy volunteers and patients with joint disease.

OBJECTIVES--To analyse synovial fluid and serum concentrations of the amino-propeptide of the type III procollagen (PIIINP) in normal individuals and patients with joint disease, and to explore the relationship between synovial fluid PIIINP concentrations and the rheumatological diagnosis, local inflammation, and joint disease. METHODS--A radioimmunoassay was used to measure the PIIINP concentrations in serum and knee joint synovial fluid from 16 healthy volunteers and patients with osteoarthritis (OA) (n = 40), rheumatoid arthritis (RA) (n = 30), and psoriatic arthritis (PsA) (n = 12). The PIIINP measurements were related to demographic data, synovial fluid leucocyte counts, and radiographic changes at the knee. RESULTS--Serum PIIINP concentrations were greater in each of the disease groups than in control subjects, but there were no differences between the disease groups. Synovial fluid concentrations of PIIINP were much greater than those in serum, indicating local production, and were significantly greater in RA than in other disease groups (p < 0.001). There was only a weak positive correlation between synovial fluid leucocyte counts, some radiographic changes, and synovial fluid PIIINP concentrations. CONCLUSIONS--These data suggest that synovial fluid PIIINP concentrations may reflect local synovial proliferative processes in joint disease, and that they could be of diagnostic and prognostic value in inflammatory arthropathies.     

Serum procollagen III peptide concentration in iron overload

Abstract: Patients with severe iron overload may develop hepatic fibrosis due to iron toxicity. Unfortunately, the follow-up of the fibrogenic activity during treatment by histological examination of tissue biopsies carries potential side effects, and may therefore not be justified ethically. Recently, the serum concentration of procollagen type III peptide (S-PIIINP) has been shown to be a valid serum marker of the activity of collagen metabolism in conditions with hepatic fibrosis unrelated to iron overload. In order to evaluate the potential usefulness of this test in patients with fibrosis due to iron overload, we investigated the relationship between the PIIINP serum concentration and the size of iron overload in 18 patients with hereditary haemochromatosis (HH) and in 14 patients with transfusional iron overload. A close correlation was found between S-ferritin and S-PIIINP (r=0.73, p<0.0001). Follow-up of 6 patients during iron depletion treatment revealed a normalization of the serum aminotransferase concentration before normalization of S-PIIINP was found. This may indicate that excess iron directly induces an increase in fibrogenesis rather than the increased fibrogenesis is secondary to hepatocellular injury caused by iron excess. Thus, serial measurements S-PIIINP may be useful in follow-up of the fibrogenic process due to iron overload.     

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 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.     

Relationship between serum and hepatic 7S fragments of type IV collagen in chronic liver disease

We evaluated the mechanism of increased serum concentrations of the 7S fragment of the N-terminal domain of type IV collagen (7S collagen) in chronic liver disease. We measured the concentrations of hepatic-free and deposited 7S collagens after extraction with Tris-HCl buffer and bacterial collagenase, then compared them with the serum levels in 8 normal controls and 48 patients with chronic liver disease. The hepatic 7S collagen levels extracted with Tris-HCl buffer and collagenase accounted for 7% and 93%, respectively, of the total 7S collagen levels in normal controls. Both hepatic 7S collagen levels as well as serum levels increased in accordance with the progress of liver disease. Serum levels of 7S collagen showed a closer correlation with the hepatic 7S collagen levels extracted with Tris-HCl buffer (r = .822), compared with those extracted with collagenase (r = .382). On the other hand, the histological degrees of liver fibrosis were highly correlated with the hepatic collagenase-extracted 7S collagen levels (r = .822), compared with serum and the hepatic Tris-HCl buffer-extracted levels (r = .478 and r = .537, respectively). Although there was no difference in serum and hepatic 7S collagen levels between B and C viral patients, the serum and hepatic Tris-HCl buffer-extracted 7S collagen levels were higher in patients with alcoholic cirrhosis than patients with viral cirrhosis. However, the hepatic collagenase-extracted levels were similar in both groups. Gel filtration demonstrated that the serum and hepatic Tris-HCl buffer-extracted 7S collagens were mainly eluted in the macromolecular 7S collagen-reactive fraction in cirrhosis, whereas the hepatic collagenase-extracted 7S collagen was eluted in the authentic 7S collagen-reactive fraction. The results suggest that serum 7S collagen levels are not a particularly reliable measure of hepatic fibrosis but reflect the enhanced metabolism, especially synthesis of type IV collagen in the liver. (Hepatology 1996 May;23(5):1154-8)     

Procollagen type III aminoterminal peptide in serum in idiopathic myelofibrosis and allied conditions: relation to disease activity and effect of chemotherapy

The serum concentration of the aminoterminal propeptide of type III procollagen (PIIINP) was measured serially in patients with idiopathic myelofibrosis and other myeloproliferative syndromes. Two different assays were applied, the RIA-gnost assay (Hoechst, Frankfurt, FRG) and a new equilibrium RIA for the N-terminal propeptide of human type III procollagen (Farmos Diagnostica, Oulu, Finland). A positive correlation was found between the results obtained by the two RIA's (rho = 0.90, P less than 0.001). The highest propeptide levels were recorded in patients with idiopathic myelofibrosis, particularly in those with active disease. Elevated serum PIIINP levels decreased during treatment with various cytotoxic drugs, including intensive chemotherapy. By contrast, serum PIIINP was unchanged or increased in patients undergoing interferon alpha-2b therapy. Gel filtration of sera on Sephacryl S-300 column (Pharmacia, Sweden) showed that smaller PIIINP related peptides dominated in healthy subjects and in osteomyelosclerosis with stable disease. Conversely, the relative proportion of intact propeptide increased in accelerating disease stages and acute myelofibrosis. In conclusion, the present study implicates serum PIIINP as a useful indicator of disease activity in idiopathic myelofibrosis. The propeptide also appears to be a sensitive sero-marker of chemotherapy effect on fibrogenesis related to clonal myeloproliferation. Finally, the propeptide is suggested as an early predictor of relapse during cytotoxic therapy.     

Collagen metabolites in the peripheral and splanchnic circulation of patients with Crohn disease.

BACKGROUND: Fragments of collagen arising during synthesis and breakdown have been suggested as markers of fibrous tissue remodelling in Crohn disease. We compared serum concentrations of the C-terminal propeptide of collagen I (PICP), the N-terminal propeptide of collagen III (PIIINP) and the C-terminal telopeptide of type I collagen (ICTP) in the splanchnic and systemic circulation in Crohn disease requiring segmental intestinal resection. METHOD: 15 consecutive patients undergoing surgery due to strictures or continuous inflammation. Male:female ratio was 6:9. Blood was drawn from a peripheral vein prior to surgery. Immediately before intestinal resection, additional samples were drawn from the antecubital vein and from a mesenteric vein draining the affected intestinal segment. PIIINP, PICP and ICTP were measured with radioimmunoassays. RESULTS: Pre-surgery S-ICTP (median 5.5 microg/L; range 3.2-17.2 microg/L) was significantly increased in peripheral blood compared with healthy controls (median 2.6 microg/L; range 0.6-5.7 microg/L), P < or = 0.05. By contrast, S-PICP (median 98 microg/L; range 62-137 microg/L) and S-PIIINP (median 2.5 microg/L; range 1.2-7.4 microg/L) were significantly lower than S-PICP (median 133 microg/L; range 66-284 microg/L) and S-PIIINP (median 3.4 microg/L; range 1.0-7.1 microg/L) in healthy controls, P < or = 0.05. During surgery. no difference in S-PICP and S-PIIINP was documented between peripheral blood and splanchnic blood. In contrast, S-ICTP was increased in splanchnic blood (median 6.2 microg/L; range 2.7-17.4) compared to peripheral blood (median 5.0 microg/L; range 3.1-13.4) (P=0.05). CONCLUSION: The present study provides further evidence that the altered intestinal collagen metabolism in Crohn disease is reflected in the local and systemic circulation.     

Clinical significance of the serum levels of the 7S domain of type IV collagen in patients with primary biliary cirrhosis

The serum levels of the 7S domain of type IV collagen were measured with a radio-immunoassay in 42 patients with primary biliary cirrhosis (asymptomatic: n = 28; symptomatic: n = 14), 10 patients with chronic active hepatitis, 10 patients with liver cirrhosis and 10 healthy female controls. Serum levels of the 7S domain of type IV collagen were: 4.28 ng/mL (3.88-4.72 ng/mL; mean and range of mean +/- s.d.) in healthy controls; 5.97 ng/mL (5.07-7.02 ng/mL) in patients with chronic active hepatitis; 8.23 ng/mL (6.40-10.58 ng/mL) in patients with liver cirrhosis; and 6.79 ng/mL (4.76-9.67 ng/mL) in patients with primary biliary cirrhosis. Patients with liver cirrhosis and primary biliary cirrhosis had higher levels of serum 7S domain of type IV collagen than healthy controls (P < 0.001, respectively). Serum levels of the 7S domain of type IV collagen in patients with asymptomatic primary biliary cirrhosis, 5.83 ng/mL (4.55-7.48 ng/mL) were significantly lower than those in symptomatic primary biliary cirrhosis, 9.18 ng/mL (6.53-12.91 ng/mL; P < 0.001). Serum levels of the 7S domain of type IV collagen increased significantly along with advancement of the histological stages of primary biliary cirrhosis. Serum levels of the 7S domain of type IV collagen in the paired sera of eight patients with asymptomatic primary biliary cirrhosis (mean interval 30 months, range 12-48 months) showed significant rises during the intervals (P < 0.05), while serum levels of albumin and total bilirubin did not change significantly during these intervals.(ABSTRACT TRUNCATED AT 250 WORDS)     

High serum level of procollagen type III amino-terminal peptide contributes to the efficacy of spironolactone and angiotensin-converting enzyme inhibitor therapy on left ventricular hypertrophy in essential hypertensive patients.

We recently demonstrated that spironolactone may have beneficial effects on left ventricular hypertrophy in selected patients with essential hypertension undergoing treatment with an angiotensin-converting enzyme (ACE) inhibitor. To clarify the possible mechanisms by which spironolactone improves cardiac hypertrophy, we investigated the change in serum procollagen type III amino-terminal peptide (PIIINP) in 11 patients with essential hypertension treated with spironolactone and an ACE inhibitor for 24 weeks. Both blood pressure and serum PIIINP levels were significantly decreased by treatment. There was a statistical significant correlation between the changes in LVMI and those in PIIINP. The reduction in PIIINP was significant in patients whose initial serum PIIINP levels were above the normal range. Before treatment, there were no statistically significant correlations between serum PIIINP levels and either LVMI, blood pressure, or plasma aldosterone concentration. Essential hypertensive patients matched in terms of duration of therapy, blood pressure and LVMI and treated with an ACE inhibitor alone showed no change in serum PIIINP levels. In conclusion, the results of the present study demonstrate that patients with essential hypertension and high serum levels of PIIINP are particularly responsive to MR blockade in terms of left ventricular hypertrophy. Moreover, these results suggest that spironolactone limits cardiac collagen turnover in such patients. Larger studies may provide definitive evidence for the involvement of aldosterone in left ventricular hypertrophy in patients with abnormally high PIIINP levels.     

Autoantibodies to type II collagen: occurrence in rheumatoid arthritis, other arthritides, autoimmune connective tissue diseases, and chronic inflammatory syndromes.

Serum IgG antibodies to native and denatured human type II collagen (Col II) were measured using an enzyme linked immunosorbent assay (ELISA). One hundred and thirty one patients with various forms of arthritis such as rheumatoid arthritis (RA), ankylosing spondylitis (AS), psoriatic arthritis (PSA). Reiter's Syndrome (RS), osteoarthritis (OA), and gout, 60 with autoimmune connective tissue disease, and 37 with the chronic inflammatory conditions--graft versus host disease and leprosy--were studied. With the exception of RS, PSA, OA, and gout, significant levels of Col II antibodies were detected in each disease group. Blocking studies with types I and II collagen on selected serum samples confirmed the specificity to native Col II, though some cross reactivity was apparent with denatured collagen. The patients with RA who were Col II antibody positive tended to fall into stage III of disease progression. There was, however, no correlation with rheumatoid factor, erythrocyte sedimentation rate, or disease duration and this, together with the finding that Col II antibodies are present in a wide array of diseases, makes their role in the pathogenesis of RA questionable. They may arise as a secondary disease perpetuating mechanism in some patients, or in turn may be an epiphenomenon secondary to generalised disturbed immunoregulation or B cell hyperreactivity, or both, that characterises these clinical conditions.     

Different effects of thyroid disease on serum levels of procollagen III N-peptide and hyaluronic acid

Serum levels of procollagen III N-peptide (PIIINP) and hyaluronic acid (HA) reflect secretion of procollagen III and HA from fibroblasts, a cell type sensitive to thyroid hormones. Serum PIIINP and HA concentrations were measured in different thyroid function states, the former by two different assays, one detecting intact and aggregated PIIINP (PIIINP assay) and another detecting low mol wt degradation products of PIIINP as well (Fab-PIIINP assay). Two thirds of 28 hyperthyroid patients had elevated serum PIIINP values (mean, 192% in the PIIINP assay and 243% in the Fab-PIIINP assay) compared to age- and sex-matched controls (P less than 0.001). Normalization was seen after medical treatment (n = 16). In contrast, serum HA levels increased from 49 +/- 30 to 68 +/- 37 ng/mL (P less than 0.01) when a euthyroid state was achieved. Hypothyroid patients (n = 23) had increased serum HA levels (mean, 162%; P less than 0.05), which normalized after L-T4 treatment (71 +/- 50 before and 41 +/- 20 ng/mL after treatment (n = 16; P less than 0.02). L-T4 treatment also increased serum PIIINP levels significantly. Subjects with familial dysalbuminemic hyperthyroxinemia (n = 8), representing a situation with elevated circulating levels of T4 due to enhanced protein binding, and patients with nontoxic goiter with serum TSH levels ranging from 3.6-0.05 mU/L had normal serum levels of PIIINP and HA. Our data suggest that the secretion of procollagen III and that of HA from fibroblasts are influenced differently by thyroid hormones, since the secretion of procollagen III seems enhanced by thyroid hormones, whereas the secretion of HA seems reduced. Neither euthyroidism with enhanced serum T4 levels (familial dysalbuminemic hyperthyroxinemia) nor euthyroidism with reduced serum TSH levels (nontoxic goiter) seems associated with alterations at the connective tissue level.     

Seromarkers of collagen I and III metabolism in active Crohn's disease. Relation to disease activity and response to therapy.

Crohn's disease is characterised by gradual development of intestinal fibrotic lesions containing large amounts of collagen type I, III, and V. Measurement of circulating connective tissue metabolites has emerged as a useful tool for assessment of fibroproliferative activity in various diseases. Serum concentrations of procollagen peptides, N-terminal propeptide of type III procollagen (PII-INP), and C-terminal propeptide of type I procollagen (PICP), reflect the synthesis rate of the parent collagens, while the C-terminal telopeptide of type I collagen (ICTP) reflects its degradation. S-PIIINP, S-PICP, and S-ICTP were measured by radioimmunoassays in 29 patients with active Crohn's disease. S-ICTP was significantly increased, median 6.2 micrograms/l (95% CI 5.2 to 8.7 micrograms/l) versus controls 2.6 micrograms/l (2.5 to 2.7 micrograms/l) (p < 0.0001), S-PICP reduced, 100 micrograms/l (80 to 110 micrograms/l) versus 132 micrograms/l (124 to 141 micrograms/l) (p = 0.001), and S-PIIINP did not differ from controls. Patients with sustained clinical remission during prednisolone therapy exhibited an increase in S-PICP (p = 0.0052). S-PIIINP changed significantly (p = 0.0002), however, exhibiting a biphasic pattern. S-ICTP decreased (p = 0.015) in treatment responders but remained above the upper normal limit even when clinical remission had been achieved. Non-responders showed no significant changes in any of the marker molecules of collagen synthesis or degradation. Correlations were found between S-PIIINP and S-PICP (p < 0.005) and S-ICTP (p < 0.02), and between S-ICTP and S-orosomucoid (p < 0.005) and S-C reactive protein (p < 0.02). By contrast, there was no relation between the connective tissue metabolites and Harvey Bradshaw Index. These data provide evidence that collagen I degradation is increased not only in active Crohn's disease, but also in patients entering clinical remission. The concurrent normal/low-normal values of markers of collagen formation may reflect a changed local or systemic elimination of the propeptides.     

Collagen Metabolites in the Peripheral and Splanchnic Circulation of Patients with Crohn Disease

Background: Fragments of collagen arising during synthesis and breakdown have been suggested as markers of fibrous tissue remodelling in Crohn disease. We compared serum concentrations of the C-terminal propeptide of collagen I (PICP), the N-terminal propeptide of collagen III (PIIINP) and the Cterminal telopeptide of type I collagen (ICTP) in the splanchnic and systemic circulation in Crohn disease requiring segmental intestinal resection. Method: 15 consecutive patients undergoing surgery due to strictures or continuous inflammation. Male:female ratio was 6:9. Blood was drawn from a peripheral vein prior to surgery. Immediately before intestinal resection, additional samples were drawn from the antecubital vein and from a mesenteric vein draining the affected intestinal segment. PIIINP, PICP and ICTP were measured with radioimmunoassays. Results: Pre-surgery S-ICTP (median 5.5 μg/L; range 3.2-17.2 μg/L) was significantly increased in peripheral blood compared with healthy controls (median 2.6 μg/L; range 0.6-5.7 μg/L), P &#104 0.05. By contrast, S-PICP (median 98 μg/L; range 62-137 μg/L) and S-PIIINP (median 2.5 μg/L; range 1.2-7.4 μg/L) were significantly lower than S-PICP (median 133 μg/L; range 66-284 μg/L) and S-PIIINP (median 3.4 μg/L; range 1.0-7.1 μg/L) in healthy controls, P &#104 0.05. During surgery, no difference in S-PICP and S-PIIINP was documented between peripheral blood and splanchnic blood. In contrast, S-ICTP was increased in splanchnic blood (median 6.2 μg/L; range 2.7-17.4) compared to peripheral blood (median 5.0 μg/L; range 3.1-13.4) ( P = 0.05). Conclusion: The present study provides further evidence that the altered intestinal collagen metabolism in Crohn disease is reflected in the local and systemic circulation.     

Serum levels of aminoterminal type III procollagen peptide and hyaluronan predict mortality in systemic sclerosis.

Systemic sclerosis (SSc) is characterized by an excessive accumulation of collagen in skin and internal organs and increased serum concentrations of different connective tissue metabolites have been reported. In this study of 82 patients with SSc, serum concentrations of aminoterminal type III procollagen peptide (PIIINP), smaller PIIINP-related antigens (Fab PIIINP) and hyaluronan (HA) were increased as compared to healthy controls matched for age and sex. Patients with a shorter disease duration (less than 3 years) had higher serum levels of PIIINP and Fab PIIINP than patients with a longer disease duration. The highest serum concentrations of PIIINP and HA were seen in seven patients who died within 2 years.