Page 43 - Essential Haematology

Chapter 2 Erythropoiesis and anaemia / 29

Red cell Causes Red cell Causes
abnormality abnormality
Normal Microspherocyte Hereditary spherocytosis,
autoimmune haemolytic
anaemia,
septicaemia

Macrocyte Liver disease, alcoholism. Fragments DIC, microangiopathy, HUS,
Oval in megaloblastic TTP, burns, cardiac valves
anaemia

Target cell Iron deficiency, liver disease, Elliptocyte Hereditary elliptocytosis
haemoglobinopathies,
post-splenectomy

Stomatocyte Liver disease, alcoholism Tear drop Myelofibrosis,
poikilocyte extramedullary
haemopoiesis

Pencil cell Iron deficiency Basket cell Oxidant damage–
e.g. G6PD deficiency,
unstable haemoglobin
Echinocyte Liver disease, Sickle cell Sickle cell anaemia
post-splenectomy.
storage artefact

Acanthocyte Liver disease, abetalipo- Microcyte Iron deficiency,
proteinaemia, renal failure haemoglobinopathy

Figure 2.16 Some of the more frequent variations in size (anisocytosis) and shape (poikilocytosis) that may be
found in different anaemias. DIC, disseminated intravascular coagulopathy; G6PD, glucose - 6 - phosphate
dehydrogenase; HUS, haemolytic uraemic syndrome; TTP, thrombotic thrombocytopenic purpura.

architecture, cellularity and presence of fi brosis or ineffective erythropoiesis is marked. Th e reticulo-
abnormal infiltrates can be reliably determined. cyte count is low in relation to the degree of anaemia

and to the proportion of erythroblasts in the
marrow.
Ineffective e rythropoiesis
Erythropoiesis is not entirely effi cient because Assessment of e rythropoiesis
approximately 10 – 15% of developing erythroblasts
die within the marrow without producing mature Total erythropoiesis and the amount of erythropoi-

cells. This is termed ineffective erythropoiesis and it esis that is effective in producing circulating red

is substantially increased in a number of chronic cells can be assessed by examining the bone marrow,
anaemias (Fig. 2.19 ). The serum unconjugated haemoglobin level and reticulocyte count.

bilirubin (derived from breaking down haemo- Total erythropoiesis is assessed from the marrow
globin) and lactate dehydrogenase (LDH, derived cellularity and the myeloid : erythroid ratio (i.e. the
from breaking down cells) are usually raised when proportion of granulocyte precursors to red cell