Effect of Normal Cells on Viscosity of Sickle-Cell Blood

Abstract

The protean clinical manifestations of painful sickle-cell crises have been described by many authors,^1-7 but the factors responsible for precipitating the crises remain poorly understood. Many approaches to treatment of crises have been proposed; none has proved regularly effective. Blood transfusions are frequently disappointing in their failure to alter significantly the course of a well-established crisis, even when sufficient blood is given to raise the patient's hemoglobin concentration close to normal. However, despite the lack of immediate clinical improvement following transfusion, the patient frequently remains free from painful crises for 2 to 3 months thereafter. This freedom from crises persists long after the transient relief of anemia by transfusion; presumably the presence of normal donor cells in the patient's circulation exerts a protective effect against precipitation of crises. The nature of this protection is not known, but a likely mechanism is the effect of the transfused cells upon the