Canterbury DHB

Context

Clinical and Laboratory Assessment

A careful history and examination aimed at detecting any of causes of iron deficiency should be carried out. Pallor, glossitis, koilonychia may be found.

Investigations will usually show a microcytic anaemia with normal white cells and a normal or slightly elevated platelet count. Serum iron is reduced, transferrin increased, soluble transferrin receptor increased. Ferritin is low, CRP normal. A bone marrow to assess iron stores is not required. If these results are equivocal, a search will need to be made for other causes of microcytosis.

Laboratory Findings in Microcytic Anaemia

 

Hb

MCV or MCH

Serum Iron

Transferrin

Ferritin

CRP

sTFR

Iron deficiency

Up Arrow

N

Up Arrow

 

Anaemia of chronic inflammation

N or

N or

N or Up Arrow

Up Arrow

N

 

Thalassaemia trait

N or

N

N

N

N

N

 

 

 

 

 

 

 

 

Sideroblastic anaemia

N or Up Arrow

N

Up Arrow

N

N

Notes:

Transferrin may be raised by oestrogens. Soluble transferrin receptor (STFR) may be more discriminating than transferrin, and is also raised in iron deficiency.In iron deficiency, Hb and MCV both fall to the same degree. In thalassaemia trait, the MCV is markedly reduced while the haemoglobin is normal or near normal. A slight reduction in MCV due to a thalassaemia is common in Polynesian and Maori.

Problems may arise when iron deficiency complicates inflammatory bowel disease such as Crohns Disease, ulcerative colitis, or helicobacter pylori. In these situations, the combination of an inflammatory process and iron deficiency may produce conflicting results when the above tests are done. A trial of iron therapy may be warranted. Combined iron and B12/folate deficiency may also produce a confusing picture with the MCV often in the normal range.

About this Canterbury DHB document (7939):

Document Owner:

Mark Smith (see Who's Who)

Issue Date:

August 2017

Next Review:

August 2019

Keywords:

Note: Only the electronic version is controlled. Once printed, this is no longer a controlled document. Disclaimer

Topic Code: 7939