Page 423 - Essential Haematology

Chapter 29 Blood transfusion / 409

Platelets and plasma may also be collected by Leucodepletion reduces the incidence of febrile
apharesis (and centrifuging). transfusion reactions and HLA alloimmunization.

It is effective at preventing transmission of CMV
infection and in addition should reduce the theo-
Leucodepletion
retical possibility of transmission of nvCJD in
In many countries, including Britain, blood prod- countries where this has been reported.
ucts are now routinely filtered to remove the major-

ity of white cells, a process known as leucodepletion.
Red c ells

This is usually performed soon after collection and

prior to processing and is more effective than fi ltra- Packed (plasma - depleted) red cells are the treatment
tion of blood at the bedside. A blood component is of choice for most transfusions (Fig. 29.7 a). In older

defined as leucocyte depleted if there are less than subjects, a diuretic is often given simultaneously
6

5 × 10 /L white cells present. and the infusion should be sufficiently slow to avoid

(a) (b)

Figure 29.7 Blood components: (a) plasma - depleted red cells;

(c) (b) platelets; and (c) fresh frozen plasma.