title: b-Gamma-glutamyltransferase activity in human vulnerable carotid plaques.
abstract: OBJECTIVE
  The atherosclerotic plaque that is vulnerable to rupture and to superimposed thrombosis is mainly represented by a thin-cap fibroatheroma with or without ulceration/thrombosis and inflammatory infiltrates. Total serum gamma-glutamyltransferase (GGT) activity is an independent predictor for cardiovascular events. Four GGT fractions have been identified in plasma and only one of them (b-GGT) in atherosclerotic plaques, but the possible role of GGT in plaque pathophysiology has not been assessed yet. We investigated the relationships between plaque b-GGT activity and the histological features of plaque vulnerability.
  
  
  RESULTS
  Plaque GGT activity was investigated in 65 patients undergoing carotid endarterectomy; plaques were histologically characterized and immunostained for GGT. Intra-plaque total and fractional GGT activity was determined by a cost-effective test of molecular size exclusion chromatography, and compared with histological markers of plaque vulnerability. Plaque cholesterol content was also measured by chromatography. b-GGT was the only fraction detected within the atherosclerotic plaques and intra-plaque b-GGT activity correlated to plaque cholesterol content (r = 0.667, P < 0.0001), plasma b-GGT and f-GGT fractions (r = 0.249; r = 0.298, both P < 0.05). Higher b-GGT activity was found in thin-cap fibroatheromas and it was associated to histological markers of vulnerable plaques, i.e., larger necrotic areas, greater macrophage infiltration and higher cholesterol content (P < 0.05).
  
  
  CONCLUSIONS
  intra-plaque b-GGT activity correlates with the histological markers of vulnerable plaque and with plasma b-GGT in human carotid atherosclerosis; these data support the possible role of b-GGT in clinically significant atherosclerotic disease.
authors.affiliation: Histopathology Department, University Hospital, Pisa, Italy. Electronic address: a.pucci@ao-pisa.toscana.it.
authors.forename: Angela
authors.initials: A
authors.lastname: Pucci
authors.affiliation: Institute of Life Sciences, Scuola Superiore Sant'Anna, Pisa, Italy.
authors.forename: Maria
authors.initials: M
authors.lastname: Franzini
authors.affiliation: Institute of Life Sciences, Scuola Superiore Sant'Anna, Pisa, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Matteucci
authors.affiliation: Vascular Surgery Department, University of Pisa, Italy.
authors.forename: Sabrina
authors.initials: S
authors.lastname: Ceragioli
authors.affiliation: Vascular Surgery Department, University of Pisa, Italy.
authors.forename: Michele
authors.initials: M
authors.lastname: Marconi
authors.affiliation: Vascular Surgery Department, University of Pisa, Italy.
authors.forename: Mauro
authors.initials: M
authors.lastname: Ferrari
authors.affiliation: Institute of Life Sciences, Scuola Superiore Sant'Anna, Pisa, Italy; Fondazione G. Monasterio CNR-Regione Toscana, Pisa, Italy.
authors.forename: Claudio
authors.initials: C
authors.lastname: Passino
authors.affiliation: Surgical and Medical Pathology Department, University of Pisa, Italy.
authors.forename: Fulvio
authors.initials: F
authors.lastname: Basolo
authors.affiliation: Institute of Life Sciences, Scuola Superiore Sant'Anna, Pisa, Italy; Fondazione G. Monasterio CNR-Regione Toscana, Pisa, Italy.
authors.forename: Michele
authors.initials: M
authors.lastname: Emdin
authors.affiliation: Translational Research Department, University of Pisa, Italy.
authors.forename: Aldo
authors.initials: A
authors.lastname: Paolicchi
mesh_terms: D000368:Aged; D002318:Cardiovascular Diseases / Q000175:diagnosis; D002339:Carotid Arteries / Q000473:pathology*; D002340:Carotid Artery Diseases; D002784:Cholesterol / Q000097:blood; D002845:Chromatography; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D018450:Disease Progression; D016894:Endarterectomy, Carotid; D005260:Female; D015971:Gene Expression Regulation, Enzymologic; D006801:Humans; D007249:Inflammation; D008297:Male; D058226:Plaque, Atherosclerotic / Q000473:pathology*; D005723:gamma-Glutamyltransferase / Q000097:blood*
chemical_list: D002784:Cholesterol; D005723:gamma-Glutamyltransferase; C554782:gamma-glutamyltransferase, human
keywords: Atherosclerosis; Gamma-glutamyltransferase fractions; Vulnerable plaque