Preferred Sample Type
Suitable Specimen Types
- Serum
- Li Hep Plasma
Specimen Transport
Ensure that samples remain frozen during transport.Record the blood glucose concentration on the request form.
Sample Processing in Laboratory
Transport blood sample to lab as soon as possible.Sample Preparation
Separate within 30 mins. Freeze sample at -20ºC immediately after separation.Sample Stability
Freeze immediately after separationProinsulin
General Information
Clinical use
Differential diagnosis of documented spontaneous hypoglycaemia.
Application
Autonomous secretions of some, but not all, insulinomas contain an abnormally high proportion of immunoreactive proinsulin. An elevated blood level can confirm this diagnosis but a low (normal) result cannot exclude it.
Patient Preparation
Hypoglycaemia, spontaneous or whilst fasting, must first be established by regular monitoring of blood glucose levels. Blood (10 mL) collected when the whole blood glucose concentration (confirmed by laboratory analysis) is less than 2.2 mmol/L (or less than 2.5 mmol/L in patients over 60 years), should be used for the tests.
Notes
Serum is the preferred sample type.
Small blood samples from neonates should be transferred to a heparin tube so that the maximum volume of plasma may be collected.
Visible haemolysis may invalidate the result.
Reference Range
Provided by reference lab
Specifications
- EQA Status: None available