Preoperative diagnosis of a glucagon-producing tumour of the pancreas in patients with diabetes and a characteristic skin rash (necrolytic migratory erythema).
With the patient at rest after an overnight fast, take blood (10 mL) using a needle and syringe.
Transfer the blood (10 mL) to a heparin tube (do not exceed 20 U/mL blood) containing Trasylol (aprotinin, 0.2 mL, 2000 kIU). Mix by inversion. Place on ice and transfer to the laboratory. Separate the plasma in a refrigerated centrifuge. Freeze the plasma at -200C within 15 min of venepuncture. Visible haemolysis invalidates the result. Send plasma (5 mL) to the SAS laboratory. Ensure the sample remains frozen during transport.
Adults (fasting): <50 pmol/L;
Adults with a glucagonoma: usually >200 pmol/L.
Centre offering this assay
London Imperial Charing Cross Hospital Endocrine Laboratory