The highly elevated HVA results and normal dopamine results are not at
all incompatable but are suggestive of a neural crest tumour, the most
likely diagnosis for an adult patient would be a small thoracic
ganglioneuroma.
Most cases of neuroblastoma or ganglioneuroma not predominantly
located in the abdominal cavity do tend to have elevated urinary HVA and
normal dopamine in our experience.
It seems unlikely that any drug or combination could produce such an
apparent elevation of dopamine turnover indicated by an HVA of 104.
Bananas and other tropical fruit can elevate HVA levels (and also
5-HIAA levels which could be checked) but an adult would need to eat
about 5-6 bananas a day or a whole pineapple. Nuclear medicine scans
can supress the appearance of HVA in the urine... a possible
explanation for the changing levels ?.
However an interference in the chromatography is also quite possible
from p-hydroxylphenylacetic acid or a drug metabolite. Are you using
reverse phase or ion exchange ?. Reverse phase generally appears to
be subject to less interferences.
Hope this is helpful
John Earl
Neurochemistry Laboratory
New Children's Hospital
Sydney, Australia.
..................................................................................................
We have a problem with one patient who has given the following results:
Date VMA HVA Adrenaline Noradrenaline Dopamine
Volume
21-22 15 27 0.02 0.27 0.75
1.98L
22-23 21 60 0.02 0.42 1.23
2.1L
23-23 28 104 0.03 0.46 1.53
3.1L
Ref range
VMA <35 umol/24hrs
HVA < 44 umol/24hrs
Adrenaline <0.10 umol/24hrs
Noradrenaline < 0.57 umol/24hrs
Dopmaine < 2.50 umol/24hrs
Medication:
Moxonidine 200mcg twice a day
Doxazosin 4mg twice a day
Frusemide 40 mg/day
Cervistatin 300mcg a day
Zirtek and HRT.
The dopamine and HVA results do not seem compatible and we suspect
drug interference.
If you have a non HPLC assay for these please get in touch.
Any ideas welcome.
Edward Kearney.
QEQMH,
All the catecholamines and metabolites appear to be increasing with the
urine collections. Firstly one should examine the 24h creatinine results to
ascertain that all the collections are for the same time period.
The predominant increase is in HVA, the metabolite of dopamine. This
patient is on Moxonidine, which acts on alpha2adrenoreceptor and
doxazocin which is an alpha blocker. These drugs or the combination
may act as dopamine antagonists.
I suggest that both these drugs be stopped and the 24h urine collections
be repeated off medication.
Dr Jeffrey Barron
Department of Chemical Pathology
St Helier Hospital
Carshalton Surrey SM5 1AA
UK
[log in to unmask]
Tel 0181 296 2660
Fax 0181 641 2633
Fax 0181 641 2633
0181 296 2660
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