You are asked for advice by a Haematology Consultant regarding a 43 year
old female patient, recently diagnosed with non-Hodgkin's lymphoma. Urea,
creatinine, electrolytes are all normal. So are liver function tests with
the exception of alkaline phosphatase which is 7000 IU/L (upper reference
limit 126 IU/L).
Some previous Cases have produced a major concensus on interpretation, but
with large differences of opinion on the appropriate action. This Case has
produced the opposite - a major concensus on action, but with very marked
differences in opinion on interpretational advice. Perhaps because of this,
it has proved difficult to break down comments into components for scoring.
I have done my best, and to simplify matters I have ignored conditional
components (eg 'if the alkaline phosphatase was of bone origin, I
would....'). If I have misinterpreted the sense of any comments, please
forgive me in advance.
Many of us (including myself) are very disparaging of clinical colleagues
who write on a request form '?hyperthyroid' when they mean '?hypothyroid'.
This case showed that even the best of us can make just the same slip of
the e-mail finger when under stress or relaying messages through a third
party!
The Case attracted 27 participants (welcome, new participants from
Hamilton, New Zealand and from Danbury, Connecticut).
2 would check the analysis on this sample; [0.7]
5 would ask for a repeat sample. [0.7]
21 would look at alkaline phosphatase isoenzymes on this sample; [2.0]
12 would measure gamma-GT if not already measured as part of the 'liver
function tests' [1.7]
4 would measure calcium and phosphate; [1.0]
3 would measure calcium; [0.3]
1 each would measure or ask for a sample for
total protein/albumin (and possible electrophoresis); [0.7]
LDH; [0.3]
acid phosphatase; [-0.7]
CSF and serum immunoglobulins and albumin. [0.3]
4 commented 'unusually high alkaline phosphatase'; [0.7]
6 commented 'probably bony origin'; [0.0]
4 thought a liver origin was likely (eg 'space-occupying lesion of liver
likely'); [0.0]
6 participants thought the most likely diagnosis was (benign) (transient)
hyperphosphatas(aem)ia (of infancy) (Rosalki's disease) (which can occur in
adults); [0.3]
1 participant commented 'transient hypophosphatasaemia of infancy in an
adult (synonym 'benign transient hypophosphatasaemia (Rosalki et al Clin
Chem 1991; 37: 1137-1138))'; [!]
4 participants each queried
Paget's disease; [0.3]
malignancy; [0.7]
2 each queried
pregnancy; [-0.7]
drug therapy; [-1.0]
viral illness; [-1.0]
infection; [-1.0]
bone metastases. [0.3]
1 each queried
GITract disease; [-0.7]
osteomalacia; [-0.7]
total body irradiation; [-1.0]
primary biliary cirrhosis; [-0.7]
hyperparathyroidism. [-0.7]
4 participants each suggested
monitoring the alkaline phosphatase; [1.7]
a bone scan. [1.3]
3 suggested liver ultrasound; [1.7]
1 suggested viral studies [0.0]
1 suggested appropriate samples for microbiology. [0.0]
David Williams comments 'Alkaline phosphatase isoenzyme studies showed
predominantly bone. The level of alkaline phosphatase gradually declined
over the next few months; and it was thought likely that an infection had
caused a dramatic but transient rise in alkaline phosphatase'.
Sidney Rosalki comments 'in transient hyperphosphatasaemia of infancy, the
characteristic pattern is abnormally anodally migrating liver-like
isoenzyme and a characteristic bone band'.
Des Kenny comments 'transient hyperphotasaemia of infancy can be confirmed
or ruled out by electrophoresis of alkaline phosphatase isoenzymes under
appropriate conditions (methods vary, and some do not give a good enough
separation to identify the characteristic pattern).
So your pay your money, and you take your choice!
Best wishes
Gordon Challand
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