Blood, 1 January 2003, Vol. 101, No. 1, pp. 372-372
CORRESPONDENCE
To the editor:
Iron status indicators: hello new, goodbye old?
A recent Brief report1 highlighted the clinical use
of the reticulocyte hemoglobin content (CHr) in the assessment of iron status. It identified a strong correlation between CHr and an assessment of stainable bone marrow iron stores.
The conclusion that CHr could predict the degree of stainable iron
perpetuates the misunderstanding that has dogged the assessment of
"iron status" for many decades. It fails to recognize that this
status can have different levels in different parts of the iron
metabolic process. Stainable iron stores give crude and imprecise estimates of the insoluble ferric hydroxide complexes deposited in the
reticuloendothelial system. Whether or not this is a "store" or
simply iron taken out of active metabolic employment is another matter.
CHr, on the other hand, is a direct reflection of recent hemoglobin
synthesis in developing red cells. It is a measure of the
adequacy of the rate of iron supply and this, as has been amply shown
in renal anemia, can be compromised even when there is iron on deposit
in the stores. CHr is a new and valuable parameter in its own right.
The need to assess stainable iron owes more to tradition than to
clinical diagnostic science. With the availability of
parameters, such as CHr, that reflect a pathophysiologic reality, it is
time to dispense with "Fool's Gold" standards (iron pyrites, a
mineral deposit that looks like gold).
Ivor A. Cavill
Correspondence: Ivor Cavill, University of Wales College of
Medicine, Haematology, Cardiff, Wales, United Kingdom; e-mail:
cavilli{at}cf.ac.uk
References
1.
Mast AE, Blunder MA, Lu Q, Flax S, Dietzen J.
Clinical utility of the reticulocyte hemoglobin content in the diagnosis of iron deficiency.
Blood.
2002;99:1489-1491[Abstract/Free Full Text].
