title: High-sensitivity γ-glutamyltransferase fraction pattern in alcohol addicts and abstainers.
abstract: BACKGROUND
  Four fractions of gamma-glutamyltransferase (GGT) with different molecular weight (b-, m-, s-, and f-GGT) are present in human plasma. Differential GGT fraction pattern is found in non-alcoholic liver disease (NAFLD) and chronic viral hepatitis, characterized by normal or decreased b-GGT/s-GGT (b/s) ratio, respectively.
  
  
  METHODS
  Chromatographic fractional GGT analysis was performed on plasma obtained from 51 subjects: 27 alcoholics (mean (SD), age 45 (9) years; 23 males; 14 positive for viral infection), 24 abstinents from at least 1 month (43 (12) years; 20 males; 6 positive for viral infection). Twenty-seven blood donors matched for age and gender (44 (9) years; 23 males) were selected as controls.
  
  
  RESULTS
  All fractions were significantly increased in alcoholics (P<0.001), s-GGT showing the largest increase, while only m-GGT and s-GGT were elevated in abstainers (P<0.01), in comparison with controls. The b/s ratio was significantly lower in both alcoholics and abstainers than in controls (median (25th-75th perc.): 0.10 (0.07-0.15), 0.16 (0.10-0.24), 0.35 (0.29-0.53), respectively, P<0.001). Viral infection did not significantly changes absolute values of individual GGT fractions in alcoholics, but the b/s ratio was significantly lower in virus positive than in virus negative subjects (0.08 (0.05-0.12), 0.14 (0.09-0.20), respectively, P<0.01).
  
  
  CONCLUSIONS
  The fraction pattern analysis might increase the specificity of GGT as biomarker of alcohol abuse, especially concerning the differential diagnosis between alcoholism and NAFLD, a common cause of elevated GGT level in the general population.
authors: Scuola Superiore Sant'Anna, Pz. Martiri della Libertà 33, 56127 Pisa, Italy. m.franzini@sssup.it
authors: Maria
authors: M
authors: Franzini
authors: Irene
authors: I
authors: Fornaciari
authors: Tiziana
authors: T
authors: Vico
authors: Marco
authors: M
authors: Moncini
authors: Valerio
authors: V
authors: Cellesi
authors: Milo
authors: M
authors: Meini
authors: Michele
authors: M
authors: Emdin
authors: Aldo
authors: A
authors: Paolicchi
mesh_terms: D000328:Adult; D000368:Aged; D000437:Alcoholism / Q000097:blood / Q000175:diagnosis* / Q000201:enzymology*; D015415:Biomarkers / Q000097:blood; D002853:Chromatography, Liquid / Q000592:standards; D003937:Diagnosis, Differential; D005234:Fatty Liver / Q000175:diagnosis / Q000201:enzymology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D065626:Non-alcoholic Fatty Liver Disease; D013695:Temperance; D005723:gamma-Glutamyltransferase / Q000097:blood*
chemical_list: D015415:Biomarkers; D005723:gamma-Glutamyltransferase