Suggested protocol for investigation of a raised GGT in an asymptomatic patient without risk factors for or clinical features of liver disease

Recommended investigation for isolated raised abnormal gamma glutamyl transpeptidase(GGT) in an asymptomatic patient without risk factors for or clinical features of liver disease in primary care (1):

• GGT has limited utility as a primary liver test
• the measurement of GGT is recommended in particular to establish the likely origin of a raised Alk Phos
• there is no clear consensus on thresholds for further investigation (1)
  • suggested that if a mildly raised GGT (<3 upper limit of normal (ULN)) then this is a justification for interval retesting
  • if GGT rises >5 ULN justify consideration of ultrasound if cause is not apparent

Notes:

• in the absence of clear guidance it is recommended that if results >2 ULN (unexplained by laboratory tests)
  • referral to secondary care is indicated (1)

Reference:

1. Clinical Knowledge Summaries (accessed 6/4/07). How should I investigate an isolated 'slightly raised' gamma glutamyl transpeptidase in an asymptomatic adult? www.cks.library.nhs.uk