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 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.     

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.     

Increased type I collagen degradation correlates with disease severity in rheumatoid arthritis.

OBJECTIVES--To assess the extent and clinical significance of type I collagen degradation in rheumatoid arthritis (RA). METHODS--Serum samples from 90 consecutive patients with RA from a cross-sectional population based study and 90 age- and sex-matched controls were analysed with the new assay of cross-linked carboxyterminal telopeptide of type I collagen (ICTP). RESULTS--Patients with RA had significantly higher concentrations of ICTP than the controls. ICTP correlated strongly with measures of impairment in RA, such as the erosive state of joint disease (ES) (r = 0.57, p < 0.001) and Keitel function test (KFT) (r = 0.49, p < 0.001), and more weakly with various disease activity markers. When erythrocyte sedimentation rate (ESR), ES or KFT were used as indicators of disease severity among the patients with disease duration over five years, ICTP distinguished the more serious RA from milder cases. CONCLUSIONS--Elevated serum concentrations of ICTP are common in RA and are associated with signs of aggressive disease.     

Collagen metabolism and enzymes of the urokinase plasminogen activator system in chronic myeloproliferative disorders: correlation between plasma-soluble urokinase plasminogen activator receptor and serum markers for collagen metabolism

Extracellular proteolytic enzymes of the urokinase-type plasminogen activator (uPA) system and the family of metalloproteinases (MMPs) catalyse the matrix degradation and remodelling processes characteristic of invasive malignant disorders. In a cohort of 50 patients with chronic myeloproliferative disorders (MPD) serum markers for collagen metabolism were compared to plasma levels of enzymes of the uPA and MMP system. Serum aminoterminal propeptide of type III procollagen (S-PIIINP) (P < 0.0001) concentration was significantly higher in the patients (median 3.7 micro g/L vs. 2.5 micro g/L) compared with controls. In a subgroup analysis comprising patients with myelofibrosis (MF), polycythaemia vera (PV) and essential thrombocythaemia (ET), respectively, S-PIIINP levels differed significantly with the highest values found in patients with MF (MF vs. PV vs. ET; P = 0.0027). Serum concentration of carboxyterminal telopeptide of type I collagen (S-ICTP) (P = 0.0006), reflecting type I collagen degradation, was significantly higher in patients compared with controls (median 4.0 micro g/L vs. 2.7 micro g/L). When comparing S-ICTP measurements between patient subgroups and controls there were only significantly higher values among MF and PV patients (MF vs. controls; P < 0.0001, PV vs. controls; P = 0.0016). A significant correlation between the marker for collagen synthesis (S-PIIINP) and degradation (S-ICTP) (r = 0.59; P < 0.0001) was demonstrated. A correlation analysis between serum markers for bone marrow remodelling processes (S-PIIINP, S-ICTP and S-hyaluronan) and plasma-soluble urokinase plasminogen receptor (suPAR) disclosed a significant relationship between suPAR and S-PIIINP (r = 0.48; P = 0.0009), S-hyaluronan (r = 0.56; P < 0.0001) and S-ICTP (r = 0.47; P = 0.0013), respectively. Plasma levels of MMP-2 and -9 were not correlated to serum markers for collagen metabolism. These findings suggest that enzymes of the uPA system might participate in the bone marrow remodelling processes characteristic of MPD.     

Connective tissue metabolites in serum as markers of disease activity in patients with rheumatoid arthritis

The serum levels of aminoterminal type III procollagen peptide (S-PIIINP), immunoreactive prolyl 4-hydroxylase protein (S-IRPH), 7S domain of collagen type IV (S-Col IV, 7S), and fragment P1 of laminin (S-Lam), which are associated with the metabolism of extracellular interstitial collagens and basement membranes, were measured sequentially for two years in 14 rheumatoid arthritis (RA) patients undergoing disease modifying antirheumatic drug treatment. Elevated S-PIIINP, S-IRPH, and S-Col IV, 7S levels were demonstrated in active RA. In active disease the metabolites showed some correlation with clinical and serological signs of disease activity. A high average synovial fluid/serum concentration ratio of PIIINP and of Col IV, 7S supports the concept that the increased serum levels of PIIINP and Col IV, 7S originated from the diseased joints. After 2 years of treatment a decline was observed in S-PIIINP and S-Col IV, 7S in treatment responders. However, the median levels of S-PIIINP and S-IRPH were still above the upper limit of normal, suggesting smouldering, subclinical inflammatory processes. S-Lam remained within the normal range in active and inactive disease.     

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.     

The value of synovial fluid analysis in the assessment of knee joint destruction in arthritis in a three year follow up study

OBJECTIVES: To assess the predictive significance of synovial fluid (SF) analysis for progressive radiological knee joint destruction in arthritis. METHODS: Altogether 55 patients with arthritis and knee joint effusion were included in the study. The diagnosis was rheumatoid arthritis (RA) for 44 of them, chronic seronegative spondylarthropathy for seven and juvenile rheumatoid arthritis for four. The mean age of the patients was 51.8 (SD 14.9, range 19-82) years, and the mean duration of disease 10.9 (SD 9.2, range 0.5-37) years. In addition to the routine laboratory tests, different markers of collagen synthesis and breakdown in serum and SF were assessed. The radiological grade of the knee joint was assessed by Larsen's method at the baseline and after a three year follow up. RESULTS: During the follow up, Larsen's grade deteriorated in 22 (40%) patients. These patients had a significantly higher median level of cross linked carboxyterminal telopeptide of type I collagen (ICTP) in SF at entry than those who had a stable index (p = 0.035). Serum ICTP did not have any predictive value for a specific joint. The median levels of total SF leucocytes (p = 0.012) and the subgroup of polymorphonuclear leucocytes (p = 0.018) were higher in the patients with a stable Larsen's index. However, the relation of SF leucocyte level to radiological progression could not be confirmed in the RA group. CONCLUSION: It is concluded that SF analysis may help in the identification of patients with inflammatory arthritis who are at risk for progressive destruction in a particular joint. A high total SF leucocyte level is not necessarily associated with a poor prognosis. Instead, a high SF ICTP level seems to reflect accelerated bone degradation.     

Abnormal bone turnover in monoclonal gammopathy of undetermined significance: analyses of type I collagen telopeptide,osteocalcin, bone-specific alkaline phosphatase and propeptides of type I and type III procollagens

Abstract: The main difference between monoclonal gammopathy of undetermined significance (MGUS) and multiple myeloma (MM) is the presence of lytic bone destructions in the latter. About 20% of MGUS patients develop MM, and histomorphometric studies have shown disturbed bone turnover rates in some of these patients. This study was performed in order to evaluate whether serum analyses of the C-terminal telopeptide of type I collagen (ICTP), as a reflector of bone degradation, and of osteocalcin, bone-specific alkaline phosphatase (bAP) and the C-terminal propeptide of type I procollagen (PICP), as markers of bone formation, might give information on disturbancies of bone metabolism in MGUS. Furthermore, serum N-terminal propeptide of procollagen III (PIIINP) might give information on disturbances in collagen III metabolism in the bone marrow. In the 35 patients examined, serum ICTP was elevated in 12 patients (34%), serum PIIINP elevated in 6 patients (17%), serum osteocalcin elevated in 11 patients (31%), serum bAP elevated in 6 patients (17%), and serum PICP elevated in 4 patients (11%). Serum ICTP correlated significantly with PIIINP (r=0.72, p<0.001), and with serum osteocalcin (r=0.57, p<0.001) and serum bAP (r=0.51, p=0.002). These findings indicate disturbancies of bone turnover and affected collagen metabolism in some MGUS patients. Follow-up observation may reveal any prognostic value of these findings.     

Serum markers of bone metabolism in multiple myeloma: prognostic value of the carboxy-terminal telopeptide of type I collagen (ICTP)

This study was performed to evaluate the prognostic significance of serum markers of bone and collagen metabolism in multiple myeloma. Serum C-terminal telopeptide of type I collagen (ICTP) reflects degradation of bone, whereas serum osteocalcin, together with serum C-terminal propeptide of procollagen type I (PICP) and serum bone-specific alkaline phosphatase (bAP) reflect synthesis of bone matrix. The N-terminal propeptide of procollagen type III (PIIINP) in serum reflects synthesis of type III collagen. We analysed frozen sera from 109 patients with newly diagnosed multiple myeloma. Serum ICTP was elevated (>5.0μg/l) in most patients (median 6.6 μg/l, range 1.4–29.4 μg/l). Serum PIIINP was elevated (>4.2μg/l) in 46% (median 4.0 μg/l, range 1.4–20.1 μg/l). Serum PICP was generally within the reference limits, whereas serum osteocalcin and serum bAP were elevated in 19% and 37%, respectively. Serum ICTP correlated with serum PIIINP, serum β₂-microglobulin (β₂m), serum calcium, performance status, and stage. In univariate analysis, the test variables serum ICTP ( P =0.026) and serum osteocalcin ( P =0.036) were found to be of prognostic value, but PIIINP, PICP, or bAP in serum were not. Serum ICTP and serum β₂m had a similar prognostic value. In multivariate analysis, serum calcium showed the highest prognostic significance, and serum β₂m was the only other variable of independent prognostic value. However, in normocalcaemic patients, serum ICTP showed the highest prognostic significance, followed by serum osteocalcin. Thus, the serum levels of ICTP and osteocalcin seem related to bone turnover and calcium metabolism, and provide further information about myeloma activity, particularly in normocalcaemic patients.     

Dupuytren's disease in type I diabetic subjects: investigation of biochemical markers of type III and I collagen

OBJECTIVE: To clarify whether biochemical markers of collagen type III and I metabolism show alterations in type I diabetic subjects with Dupuytren's disease (DD) compared to those without DD. METHODS: DD was assessed in a total of 28 type I diabetic subjects, mean age 43.4 +/- 9.5 (SD) and duration of diabetes 25.2 +/- 9.7 years. Concentrations of aminoterminal propeptide of type III procollagen (PIIINP), carboxyterminal propeptide of type I procollagen (PICP) and carboxyterminal cross-linked telopeptide of type I collagen (ICTP) in serum and excretion of cross-linked N-telopeptides of type I collagen (NTX) and deoxypyridinoline crosslinks (DPyr) into urine were measured. RESULTS: The prevalence of DD was 32% (9 of 28 diabetic subjects). Average serum ICTP was 2.7 +/- 0.8 micrograms/l in subjects without DD and 3.6 +/- 1.2 micrograms/l with DD (p = 0.0276). No significant association between other collagen markers and DD was found. The reference intervals of PIIINP and ICTP were exceeded only in 1 and 2 subjects, respectively, and they both had DD. CONCLUSION: The degradation of type I collagen might be increased in diabetic subjects with DD. The overall implication was that synthesis or degradation of type III and I collagen in diabetic subjects with DD did not differ enough from those without DD to reflect changes in the biochemical markers of type III and I collagen.     

Myocardial collagen metabolism in failing hearts before and during cardiac resynchronization therapy

BACKGROUND: In patients with heart failure cardiac resynchronization therapy (CRT) leads to reverse ventricular remodelling. AIM: To evaluate whether myocardial collagen metabolism in patients with heart failure is implicated in adverse ventricular remodelling and response to CRT. METHODS: Collagen synthesis and degradation were assessed from the concentrations of aminoterminal propeptides of type I and type III collagen (PINP and PIIINP) and carboxyterminal telopeptide of type I collagen (ICTP), respectively, in serum of 64 patients with heart failure before and after 6 months of CRT. Forty-six patients (72%) showed a > 10% reduction in LV end-systolic volume at follow-up and were classified as responders to CRT, the other 18 patients (28%) were classified as non-responders. RESULTS: Responders demonstrated a mean (+/-SEM) increase of serum PINP and PIIINP during follow-up, from 32.9+/-2.2 to 46.7+/-4.0 microg/L (p < 0.001) and from 4.59+/-0.24 to 5.13+/-0.36 microg/L (p < 0.05), respectively. In non-responders, serum PINP and PIIINP remained unchanged during follow-up. At baseline, responders had significantly lower serum PINP than non-responders (32.9+/-2.2 vs. 41.8+/-4.3 microg/L; p < 0.05). ICTP levels of responders at baseline tended to be higher than in non-responders (3.54+/-0.56 vs. 2.08+/-0.37 microg/L, p = ns), and in both groups ICTP levels did not change upon CRT. CONCLUSION: Reverse LV remodelling following CRT is associated with increased collagen synthesis rate in the first 6 months of follow-up.     

Markers of type I and III collagen turnover as indicators of growth velocity in very low birth weight infants

Monitoring postnatal growth in very low birth weight (VLBW) infants is complicated by the difficulty of obtaining reliable measurements. A need thus exists for safe and reliable indicators of such infants' short-term growth velocity. We set out to study whether markers of type I collagen synthesis [amino-terminal propeptide of type I procollagen (PINP)] or degradation [via the matrix metalloproteinase pathway, carboxyl-terminal telopeptide of type I collagen (ICTP)] or of type III collagen synthesis [amino-terminal propeptide of type III procollagen (PIIINP)] could serve as such indicators. PINP, ICTP, and PIIINP were measured for 48 VLBW infants (mean birth weight, 923 g; range, 540-1485 g; mean gestational age, 27.6 wk; range, 23.7-32.7 wk) at the age of 1, 2, 4, and 8 wk. At each time point, these were compared with concurrent growth velocity rigorously assessed by frequent lower leg (knemometry) and weight measurements. PINP showed a significant positive correlation with lower leg growth velocity at 1, 2, and 4 wk and with weight growth velocity at 2, 4, and 8 wk. PIIINP showed a significant positive correlation with lower leg growth at 1, 2, and 8 wk and with weight growth at 2 and 8 wk. The ICTP/PINP ratio, reflecting type I collagen degradation in relation to its synthesis, showed close negative correlations with lower leg growth at 1 wk (r = -0.46; P = 0.003), 2 wk (r = -0.51; P = 0.002), and 4 wk (r = -0.56; P = 0.001) and with weight growth at 2 wk (r = -0.39; P = 0.018), 4 wk (r = -0.59; P = 0.0003), and 8 wk (r = -0.53; P = 0.005). A high ICTP/PINP ratio was an accurate predictor of impaired growth; a high ICTP/PINP ratio was a more rapid and at least as sensitive and specific indicator of slow growth as weight gain. We conclude that PINP, PIIINP, and the ICTP/PINP ratio all reflect postnatal growth velocity in VLBW infants. The most robust of these indicators is the ICTP/PINP ratio, which may thus serve as a clinical tool in assessing short-term growth of these infants.     

Influence of primary coronary intervention on myocardial collagen metabolism and left ventricle remodeling predicted by collagen metabolism markers

The aims of the present study were to analyze cardiac collagen metabolism changes in vivo during acute and nonacute phases of ST elevation myocardial infarction (STEMI) in patients who were treated with primary coronary intervention (PCI) only, and to determine the predictive significance of collagen I and III synthesis markers (PICP, PIIINP) as well as the collagen I degradation marker (ICTP) on left ventricular function and volume changes after STEMI. Serum levels of the carboxy-terminal propeptide of type I procollagen (PICP) and amino-terminal propeptide of type III procollagen (PIIINP) assessed on the 30th day and the carboxyterminal telopeptide located at the C end of collagen type I (ICTP) assessed on the 7th day after STEMI were significantly higher (P = 0.01, P = 0.019, P = 0.04, respectively) in the PCI unsuccessful group than in the PCI successful group. These findings support the theory that early and successful PCI not only limits the amount of muscle necrosis but also protects cardiac collagen from ischemia-related injury. PICP and PIIINP levels assessed on the fourth day after acute STEMI enables us to predict the development of left ventricular function (EF) and end-diastolic volume changes over the course of 6 months, irrespective of the initial EF or revascularization success.     

Biochemical markers of types I and III collagen and limited joint mobility in type 1 diabetic patients

Abstract. Limited joint mobility (LJM), a long-term complication of diabetes, has been shown to be associated with microvascular complications of diabetes. Connective tissue alterations may contribute to the development of LJM and other diabetic complications. We tested whether biochemical markers of types I and III collagen metabolism are associated with LJM in type 1 diabetes. We studied 28 male patients of mean age 43.4 years (SD=9.5) and with a duration of diabetes of 25.2 years (SD=9.7) years. LJM assessment included goniometric measurements of the joints and classification by Rosenblooms method. We measured serum concentrations of aminoterminal propeptide of type III procollagen (PIIINP), carboxyterminal propeptide of type I procollagen (PICP) and carboxyterminal crosslinked telopeptide of type I collagen (ICTP); urinary excretion of crosslinked N-telopeptides of type I collagen (NTX) and deoxypyridinoline crosslinks (DPyr) was also measured. Although average serum PIIINP tended to be higher in subjects with moderatesevere LJM (3.1±1.3 µg/l) than in subjects with mild LJM (2.5±0.7 µg/l) or without LJM (2.6±0.4 µg/l), no significant association was found (p<0.27). Concentrations of the other collagen markers were not different in subjects with or without LJM. We conclude that synthesis and degradation of types I and III collagen in diabetic subjects with LJM did not differ from those without LJM to reflect changes in the biochemical markers of these proteins.     

Comparison of five biochemical markers of bone resorption in multiple myeloma: elevated pre-treatment levels of S-ICTP and U-Ntx are predictive for early progression of the bone disease during standard chemotherapy

Increased osteoclastic bone resorption is the major causal factor of bone disease in multiple myeloma. Recently, non-invasive methods have been developed for the estimation of bone resorptive activity. To evaluate the biological sensitivity and clinical usefulness of five biochemical assays for measuring the C-terminal telopeptide of collagen I (ICTP) in serum (beta-Crosslaps ELISA and ICTP radioimmunoassay) and urinary creatinine-adjusted excretions of pyridinoline (PYR), deoxypyridinoline (DPD) and N-terminal telopeptide of collagen I (Ntx), we performed a study of 34 consecutive newly diagnosed myeloma patients. Serum and morning-fasting, second-void urine samples were taken before the start of treatment. In total, 40 age- and sex-adjusted healthy individuals served as controls. Results were expressed as Z-scores. All test variables were highly significantly elevated in the patients (P < 0.001). Serum (S)-ICTP was elevated (Z-score > 2) in most patients (85%) and showed significantly higher Z-score values than the other markers. S-ICTP remained more sensitive than the urinary assays when patients with impaired renal function were excluded from analysis. S-ICTP and the urinary metabolites correlated significantly with skeletal morbidity. S-beta-Crosslaps correlated with the bone morbidity only when patients with renal insufficiency were excluded from the analysis. High levels of S-ICTP and urinary (U)-Ntx correlated with an increased risk for early progression of bone lesions during standard melphalan-prednisolone treatment. U-Ntx and S-ICTP are sensitive tools for estimating the increased bone resorption in multiple myeloma and are clinically useful for identifying patients with increased risk of early progression of bone disease.     

Increased serum and synovial fluid antibodies to immunoselected peptides in patients with rheumatoid arthritis.

OBJECTIVES: To investigate the role of potential immunoselected phages displaying random peptides in addition to possible antigen leads in rheumatoid arthritis (RA) by assaying the levels of synovial fluid (SF) and serum antibodies to synthetic peptides. METHODS: Serum and SF antibodies from patients and controls were measured using an enzyme linked immunosorbent assay (ELISA). RESULTS: Sera and SF from RA patients reacted significantly more strongly to a 12 amino acid peptide, EFHELGDIAIAA, that shares a significant homology with collagen type IX, than did SF and sera from control groups (p < 0.0209 and p < 0.0115, respectively). In addition, the humoral responses to a 15 amino acid peptide, GGYGDGGAHGGGYGG, derived from the glycine-rich cell wall protein (GRP) 1.8, and to a 16 amino acid synthetic peptide, LGSISESRRALQDSQR, derived from the Proteus haemolysin protein were significantly stronger in RA patients compared with healthy individuals (p < 0.0001 and p < 0.0011, respectively). CONCLUSION: Our data indicate that peptide phage libraries can be used as tools for the identification of the (auto)antigen leads that may be responsible for the initiation, perpetuation, or both, of the immune response in patients with RA.     

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.     

Elite volunteer athletes of different sport disciplines may have elevated baseline GH levels divorced from unaltered levels of both IGF-I and GH-dependent bone and collagen markers: a study on-the-field

Seventy-seven Italian eliteathletes(42 M, 35 F, mean age +/- SE: 24.4-0.7 yr, age range: 17-47 yr) of different sport disciplines (sprinters, triathletes, middle-distance runners, road-walkers, cyclists, rowing athletes, skiers, roller hockey players, swimmers) were sampled on-the-field (before a training session) for the determination of basal GH, IGF-I, C-terminal cross-linked telopeptide of type I collagen (ICTP) and amino-terminal propeptide of type III procollagen (PIIINP) levels, two GH-dependent peripheral markers of bone and collagen turnover, respectively. Basal GH concentrations were significantly higher (p<0.001) in female (5.8 +/- 1.0 ng/ml) vs male athletes (1.8 +/- 0.5 ng/ml), with a large spread of values in either gender. Mean GH levels of athletes were significantly higher than those recorded in age-matched sedentary controls (females: 2.5 +/- 0.5 ng/ml, p<0.001; males: 0.5 +/- 0.2 ng/ml, p<0.05). Among female athletes, 7/35 had basal GH values higher than the upper limit of control values (>9.5 ng/ml), while among males 7/42 had values higher than the upper limit of male sedentary controls (>3.6 ng/ml). No significant differences in basal GH concentrations were found between females taking oral contraceptives (OC) and those who did not receive this treatment (5.0 +/- 2.1 vs 6.0 +/- 1.2 ng/ml). IGF-I levels (236.4 +/- 7.8 ng/ml) were in the normal range for age in all athletes (except for 1 athlete with slightly increased levels), no significant correlation being found between GH and IGF-I levels (R2=0.0393). Mean ICTP (4.6 +/- 0.2 ng/ml) and PIIINP (4.4-0.1 ng/ml) concentrations of elite athletes were not significantly different from those recorded in age and matched healthy sedentary subjects; 4 athletes showed increased PIIINP levels and 2 had increased ICTP levels. ICTP and PIIINP levels were positively correlated with chronological age (p<0.001), a positive correlation being also found between the two markers (p<0.001). On the contrary, no significant correlation was found between basal GH/IGF-I levels and ICTP/PIIINP levels. In conclusion, the present study demonstrates that: 1) elite athletes (particularly females), which have frequently increased basal GH on-the-field, have actually normal IGF-I levels; 2) ICTP and PIIINP levels of athletes are similar to those recorded in healthy sedentary, being significantly higher in younger subjects of both groups; 3) the presence of increased basal GH levels, being associated with normal IGF-I, ICTP and PIIINP levels, is probably the result of a transient GH peak in this study group. Further additional studies are requested to verify the possible use of these peripheral GH-dependent markers for detecting exogenous chronic administration of recombinant GH in athletes.     

Circulating collagen metabolites in systemic sclerosis. Differences between limited and diffuse form and relationship with pulmonary involvement

OBJECTIVE: To study collagen metabolites in systemic sclerosis (SSc) and their relationship with clinical manifestations of the disease. METHODS: Forty-eight SSc patients, 13 with a diffuse form (dcSSc), 23 with a limited form (lcSSc) and 12 with suspected SSc not fulfilling the ACR criteria, and 31 healthy controls were examined. Serum concentrations of aminoterminal type III procollagen peptide (PIIINP), aminoterminal and carboxyterminal type I procollagen peptides (PINP and PICP) and cross-linked carboxyterminal telopeptide of collagen I (ICTP) were determined by radioimmunoassay. RESULTS: Increased serum concentrations of ICTP were found in SSc patients compared with controls. Distinctly higher levels of ICTP were observed in dcSSc than in lcSSc. High serum ICTP was correlated with skin score and acute phase reactants, and with reduced pulmonary function. Serum PIIINP concentration was elevated in both lcSSc and dcSSc. CONCLUSION: Augmented collagen catabolism accompanies the increased collagen synthesis in SSc. Serum ICTP concentration is a marker of this feature and also reflects clinical severity.