Splenomegaly in sickle cell anaemia - abstract

ABSTRACT

Traditionally sickle cell anaemia is characterised by splenic atrophy in adult life but occasional persistence of splenomegaly is now well recognized. Splenomegaly is not present at birth and reached a maximum incidence of 60-70 percent at the age of 18 months. There is then a gradual disappearance of splenomegaly which falls to 35 percent at the age of 12 years, 19 percent at the age 18 and finally to 9 percent in patients over the age of 25 years. Since the persistence of splenomegaly is frequently associated with a benign clinical course, it was felt important to find what factors favoured its persistence in some patients. High levels of foetal haemoglobin and low counts of irreversibly sickled cells (ISCs) were two factors found to be associated with persistence of splenomegaly. Low ISC counts have perviously been observed in splenomegaly and attributed to sieve like removal of these cells by the spleen. Evidence presented here suggests that low ISCs may be the cause of splenomegaly and the result. The practical implications of these observations are threefold. Firstly, it is the first evidence that ISCs may be related to tissue infarction. Secondly, occasionally splenectomy indicated on other grounds, may be deferred for fear that removal of the sieve like action of the spleen will be followed by an increased in ISCs and perhaps thrombatic phenomena. The evidence is against this. Thirdly, in children with hypersplenism, the decision to perform splenectomy or await spontaneous atrophy may be a relevant problem. It is suggested that since spontaneous atrophy is more common in cases with low Hb F levels, conservative therapy may be preferred (AU)