Page 94 - Essential Haematology

80 / Chapter 6 Haemolytic anaemias

1 Acute haemolytic anaemia in response to oxidant
RBC membrane damage stress, e.g. drugs, fava beans or infections (Table
6.4 ). The acute haemolytic anaemia is caused by

Oxidant Hb Heinz bodies
rapidly developing intravascular haemolysis with

haemoglobinuria (Fig. 6.3 a). The anaemia may
be self - limiting as new young red cells are made
GSH GSSG
with near normal enzyme levels.
Glucose 2 Neonatal jaundice.
3 Rarely, a congenital non - spherocytic haemolytic
NADP NADPH
anaemia.
G6P 6PG

G6PD These syndromes may result from different types of
severe enzyme defi ciency.
NADP
F6P
NADPH Diagnosis
Between crises the blood count is normal. Th e
enzyme deficiency is detected by one of a number

Lactate Pentose 5-P
of screening tests or by direct enzyme assay on red

cells. During a crisis the blood film may show con-
tracted and fragmented cells, ‘ bite ’ cells and ‘ blister ’

Figure 6.6 Haemoglobin and red blood cell (RBC)

cells (Fig. 6.8 ) which have had Heinz bodies
membranes are usually protected from oxidant stress
removed by the spleen. Heinz bodies (oxidized,
by reduced glutathione (GSH). In G6PD defi ciency,
NADPH and GSH synthesis is impaired. F6P, denatured haemoglobin) may be seen in the reticu-
fructose - 6 - phosphate; G6P, glucose - 6 - phosphate; locyte preparation, particularly if the spleen is

G6PD, glucose - 6 - phosphate dehydrogenase; GSSG, absent. There are also features of intravascular
glutathione (oxidized form); NADP, nicotinamide haemolysis. Because of the higher enzyme level in
adenine dinucleotide phosphate.

Frequency of G6PD-deficient
males (%)
<0.5 7.0–9.9
0.5–2.9 10.0–14.9
3.0–6.9 15.0–26.0

Figure 6.7 Global distribution of G6PD gene variants causing G6PD defi ciency. Shaded areas indicate the
prevalence of G6PD defi ciency. (From Luzzatto L. & Notaro R. (2001) Science 293 : 442, with permission.)