title: Serum carboxy-terminal propeptide of procollagen type I is a marker of myocardial fibrosis in hypertensive heart disease.
abstract: BACKGROUND
  This study was designed to investigate whether the serum concentration of the carboxy-terminal propeptide of procollagen type I (PIP), a marker of collagen type I synthesis, is related to myocardial fibrosis in hypertensive patients.
  
  
  RESULTS
  The study was performed in 26 patients with essential hypertension in which ischemic cardiomyopathy was excluded after a complete medical workup. Right septal endomyocardial biopsies were performed in hypertensive patients to quantify collagen content. Collagen volume fraction (CVF) was determined on picrosirius red-stained sections with an automated image analysis system. The serum concentration of PIP was measured by specific radioimmunoassay. Compared with normotensives, both serum PIP and CVF were increased (P<0.001) in hypertensives. A direct correlation was found between CVF and serum PIP (r=0.471, P<0.02) in all hypertensives. Histological analysis revealed the presence of 2 subgroups of patients: 8 with severe fibrosis and 18 with nonsevere fibrosis. Serum PIP was higher (P<0.05) in patients with severe fibrosis than in patients with nonsevere fibrosis. Using receiver operating characteristic curves, we observed that a cutoff of 127 microg/L for PIP provided 78% specificity and 75% sensitivity for predicting severe fibrosis with a relative risk of 4.80 (95% CI, 1.19 to 19.30).
  
  
  CONCLUSIONS
  These results show a strong correlation between myocardial collagen content and the serum concentration of PIP in essential hypertension. Although preliminary, these findings suggest that the determination of PIP may be an easy and reliable method for the screening and diagnosis of severe myocardial fibrosis associated with arterial hypertension.
authors.affiliation: Division of Cardiology, Nuestra Señora de Aránzazu Hospital, San Sebastian, Spain.
authors.forename: R
authors.initials: R
authors.lastname: Querejeta
authors.forename: N
authors.initials: N
authors.lastname: Varo
authors.forename: B
authors.initials: B
authors.lastname: López
authors.forename: M
authors.initials: M
authors.lastname: Larman
authors.forename: E
authors.initials: E
authors.lastname: Artiñano
authors.forename: J C
authors.initials: JC
authors.lastname: Etayo
authors.forename: J L
authors.initials: JL
authors.lastname: Martínez Ubago
authors.forename: M
authors.initials: M
authors.lastname: Gutierrez-Stampa
authors.forename: J I
authors.initials: JI
authors.lastname: Emparanza
authors.forename: M J
authors.initials: MJ
authors.lastname: Gil
authors.forename: I
authors.initials: I
authors.lastname: Monreal
authors.forename: J P
authors.initials: JP
authors.lastname: Mindán
authors.forename: J
authors.initials: J
authors.lastname: Díez
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers; D001706:Biopsy; D003094:Collagen / Q000378:metabolism; D004452:Echocardiography; D005260:Female; D005355:Fibrosis; D006801:Humans; D006973:Hypertension / Q000097:blood* / Q000378:metabolism / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000473:pathology*; D010446:Peptide Fragments / Q000097:blood*; D011347:Procollagen / Q000097:blood*; D012372:ROC Curve; D012680:Sensitivity and Specificity
chemical_list: D015415:Biomarkers; D010446:Peptide Fragments; D011347:Procollagen; C042813:procollagen type I carboxy terminal peptide; D003094:Collagen