Assessment of splenic and RES function of patients with thalassemia major long after partial splenic embolization: in vivo clearance study.

The activity of the remaining reticuloendothelial system (RES) and the function of the splenic remnants was estimated in 5 thalassemic patients who had undergone successful partial splenic embolization (PSE) 6 yr previously. The kinetics of 125I-heat-denatured human albumin as well as that of 51Cr-heat-damaged homologous red blood cells were applied for this purpose and the parameters derived were compared to those of nonsplenectomized as well as splenectomized thalassemics with the following results: (a) The parameters of splenic function in embolized thalassemics were found to be within the limits observed in nonsplenectomized patients. (b) Their maximum phagocytic capacity was significantly lower, not only than that found in nonsplenectomized, but also than in thalassemic patients splenectomized at about the same time. It is concluded that, 6 yr after PSE has been performed, a reorientation of the altered circulatory dynamics has taken place in the splenic remnants allowing previously blockaded areas to gain normal function. It therefore seems that, despite the continuing hemolytic stimulus, RES hyperplasia is prevented, resulting in the stable, low-level transfusion requirements that have been observed in embolized thalassemics.