Specimen Collection:
Collect fasted.
Ideally 5 full EDTA tubes should be collected to ensure there is sufficient sample to send to the UK for the full Hammersmith Gut Hormone Screen to be tested.
Only samples from the Department of Endocrinology, Greenlane are accepted for Hammersmith Gut Hormone screening. (For more information contact the Department of Endocrinology, Greenlane - phone: 09 3074949 ext. 26850)
Medical staff must not request a Hammersmith gut hormone screen without first consulting an endocrinologist, neuroendocrine surgeon or medical oncologist.
Requests for Hammersmith Gut Hormone screen MUST have "Hammersmith" written on the request form.
Patient preparation:
The patient must fast overnight, but should have a normal intake of fluids, and report to the Department of Endocrinology, Greenlane Clinical Centre, at 09:00h. Medications: PPIs (e.g. omeprazole) must be stopped for 2 weeks, and H2 blockers for 72h before the blood is taken, if gastrin is to be interpretable.
All patients must have their bloods taken by the Dept. of Endocrinology. A special procedure for specimen preparation has to be followed, including special tubes for freeze drying. For patients from outside Auckland who are unable to do this, please contact the Labplus on-call chemical pathologist via Lablink (09-307-8995) before collecting any specimens.
A covering letter from the requesting doctor, which should include patient details, is required to accompany the specimen to the Hammersmith Hospital laboratory, UK.
Specimens will be sent to SAS laboratories, Charring Cross Hospital, London after being freeze dried
Samples must be separated and frozen within 15 minutes of collection and not be allowed to thaw
Place the gently inverted tubes into an ice slurry and transport to the GLCC laboratory immediately
Paediatric Specimens
When collecting small samples from infants, please specify which hormone is of the greatest importance.
0.4mL plasma is required for a single hormone request.
Diagnostic Use and Interpretation
1. Investigation of watery diarrhoea - Request the following tests individually:
Gastrin ( ZE syndrome)
Calcitonin, CEA (medullary thyroid carcinoma)
VIP ( vipoma)
urine 5HIAA (metastatic carcinoid tumour)
For specimens for these assays, see under the specific hormone.
In this context, there is little or no extra diagnostic sensitivity obtained by requesting the Hammersmith gut hormone screen. Measurement of CGA on its own has little diagnostic utility unless a person has some identified diagnosis such as a known NET or an MEN1 syndrome.
2. Hammersmith gut hormone screen
Specimens for the Hammersmith gut hormone screen must be taken off at the Department of Endocrinology, Greenlane Clinical Centre.
The Hammersmith gut hormone screen includes the following hormones:
VIP (vasoactive intestinal peptide)
PP (pancreatic polypeptide)
gastrin
glucagon
Somatostatin (SRIF)
CART (cocaine and amphetamine regulated transcript)
chromogranin A
chromogranin B (GAWK fragment)
Medical staff must not request a Hammersmith gut hormone screen without first consulting an endocrinologist, neuroendocrine surgeon or medical oncologist.
Laboratory Notes
GLCC staff
Only samples from the Department of Endocrinology, GLCC are acceptable.
Samples must be frozen in special tubes suitable for freeze drying within 15 minutes of collection and sent from GLCC in their own Bio-bottle .
Samples must not be allowed to thaw at any point (these are precious samples and are unable to be easily recollected).
Refer to document LPCHPENDPR341 for the full procedure
NOTE:
The sample must be in a -20 o C freezer within 15 minutes of venepuncture
Delay in separation and freezing invalidates the result
Visible haemolysis invalidates the result
5 mL of plasma in individual 1 mL aliquots is required for the whole screen
Procedure:
1 Set the centrifuge at 4 o C for 5 minutes
2 Label each tube with the patient details and write 1 mL plasma
3 Inform the Trace Metals Technical Specialist at ext. 22059 or the Section Leader at ext. 22042, to expect a gut hormone sample to arrive for freeze drying
4 Once the sample is received, centrifuge the EDTA tubes immediately, set the timer for 5 minutes and press start
5 Once centrifuged, immediately accurately transfer 1 mL of plasma into each labelled pilot tube. NOTE: the exact volume is important as the sample will be reconstituted later with 1 mL of water for analysis at Charing Cross Hospital
6 Cover with parafilm and perforate this with 3-4 holes with a needle
7 Place the labelled tubes at a 45 o angle in the -20 o C freezer for 1-2 hours (the angle will assist the freeze drying process)
8 Register for GUTH
9 Transport the frozen pilot tubes in a dedicated bio-bottle to ensure they arrive frozen at LabPlus ALSS before 3pm
10 Once the sample is picked up by the courier, inform ALSS on ext. 22122, or LabLink on ext. 22000 to expect the samples
ALSS staff
HAND DELIVER to a Technical Specialist in either Trace Metals or Endocrinology. If neither are available, give to the Section Leader of Specialist Chemistry
If no-one is available, IMMEDIATELY return the Bio-bottle to an ALSS freezer and leave the sample request form on the desk of the Technical Specialist in Trace Metals
After the samples have been freeze dried by Trace Metals staff, the samples, plus a covering letter are sent at ambient temperature to:
The SAS Laboratories
Clinical Biochemistry and Medical Oncology
Charing Cross Hospital
Fulham Place Road
London W6 8RF
United Kingdom
Phone number: 0044 020 8383 0649
Trace Metals staff
Follow the procedure for freeze-drying as per document LPCHPENDIN340