The following are features of G6PD deficiency
A. episodic hemolysisB. presence of bite cells
C. presence of Heinz bodies
D. both intravascular and extra vascular hemolysis isseen
E. presence of spherocytes
Ans.
A, B, C, D, E
The episodic hemolysis that
is characteristic of G6PD deficiency is caused by exposures that generate
oxidant stress. The most common triggers are infections, in which oxygen-derived free radicals are produced
by activated leukocytes. Oxidants
cause both intravascular and extravascular hemolysis in G6PD-deficient
individuals. Exposure of G6PD-deficient red cells to high levels of
oxidants causes the cross-linking of reactive sulfhydryl groups on globin
chains, which become denatured and form membrane-bound precipitates known as Heinz bodies.[MCQ] These are seen as dark
inclusions within red cells stained with crystal violet. Heinz bodies can
damage the membrane sufficiently to cause intravascular hemolysis. Less severe
membrane damage results in decreased red cell deformability. As
inclusion-bearing red cells pass through the splenic cords, macrophages pluck
out the Heinz bodies. As a result of membrane damage, some of these partially
devoured cells retain an abnormal shape, appearing to have a bite taken out of
them. Other less severely damaged cells revert to a spherocytic shape due to
loss of membrane surface area. Both bite cells and spherocytes are trapped in
splenic cords and removed rapidly by phagocytes.
