Glucagon

Specimen:

The patient should fast overnight; 5 mL blood in special EDTA/Trasylol tube, collected on melting ice and delivered immediately to the laboratory.

Method:

Immunoasssay.

Reference Interval:

25-250 µg/L.

Application:

Diagnosis of functional glucagonoma, in patients with Diabetes mellitus and other suggestive features eg, necrolytic migratory erythema, diarrhoea, weight loss and glossitis.

Interpretation:

The test lacks specificity, with elevated glucagon levels occuring in acute illness and in patients with Diabetes mellitus who do not have a functional glucagonoma.

The diagnosis of a functional glucagonoma requires appropriate clinical features (as above), the presence of a pancreatic tumour and hyperglucagonaemia.

Many glucagonomas are non-functional.

Reference:

Tomassetti P et al. Ann Oncol. 2001; 12 Suppl 2: 95-99.