Haematological Effects of the Idiopathic Splenomegaly Seen in Uganda

Abstract

SUMMARY The haematological effects of idiopathic splenomegaly have been studied in a group of 15 Ugandan patients. The results of the main investigations were compared with those obtained in five patients with miscellaneous diseases and without palpable splenomegaly. The splenic enlargement was mainly due to reticuloendothelial hyperplasia and not to sinusoidal congestion. A normochromic anaemia was present in almost all the patients and a proportion had leucopenia and thrombocytopenia. One patient presented with a crisis of anaemia; she was later shown to have red cell G6PD deficiency which was believed to be coincidental. Three aetiological factors were found in relation to the anaemia; reduction of red cell survival time, present in all the patients, haemodilution from expansion of the plasma volume, and the exclusion of a proportion of the red cell mass from the general circulation by the spleen. Six to 39 per cent of the red cell volume, the amount varying with spleen size, was sequestered in a slow mixing compartment, believed to be the extrasinusoidal spaces (the spleen pool) in the patients with splenomegaly. No spleen pool could be shown in any of the patients without splenomegaly. Intrasplenic red cell destruction was not conspicuous and it has been suggested that the red cells, after damage from repeated stagnation in the spleen pool, are destroyed widely throughout the body. The reasons for expansion of the plasma volume is not known. It relates to spleen size but cannot wholly be explained by plasma in the spleen pool. A good result from splenectomy was obtained in six out of seven patients in whom this was undertaken. Two months after operation the red cell survival time was corrected in the patients in whom this was measured. The rise in the PCV could be explained only by substantial reduction in plasma volume.

Spleen Blood Flow and Splanchnic Haemodynamics in Blood Dyscrasia and other Splenomegalies

“…Another effect of splenomegaly in these patients was an increase in blood volume with a proportionally greater increase in plasma volume than red cell mass resulting in a haemodilutional anaemia. This has also been observed in idiopathic tropical splenomegaly and in cirrhosis (Richmond et al, 1967;Kimber et al, 1965). In blood dyscrasias (Bowdler, 1963;Blendis, Clarke & Williams, 1969a) and tropical splenomegaly (Pryor, 1967) splenectomy results in a return of the blood volume to normal, although in cirrhosis it is only partially reduced (McFadzean & Todd, 1967).…”

Hypersplenism in Wilson's disease

“…Richmond, Donaldson, Williams, Hamilton, and Hutt (1967) found marked reductions in 61Cr RBC survival in 15 patients from Uganda with splenomegaly ofunknown cause. These patients, like our patients with Wilson's disease, did not have evidence of splenic sequestration as manifested by a rise in spleen radioactivity.…”

Radiological determination of spleen size.

“…In clinical studies the length of the spleen palpable below the costal margin has often been used as an index of spleen size (Bowdler, 1967;McFadzean and 434 Todd, 1967;Richmond, Donaldson, Williams, Hamilton, and Hutt, 1967). However, this does not take into account the considerable proportion of the spleen deep to the rib cage and there is also a considerable degree of observer variation in palpation of the spleen (Blendis, Murray-Lyon, Williams, McNeilly, Shepherd, and Laws, 1969).…”