Red Cells in Sickle Cell Crisis: Observations on the Pathophysiology of Crisis

The pathophysiology of the occurrence and sickle crisis is associated with an increased resolution of sickle cell crisis is unknown. filterability of the circulating red cell and a The molecular abnormality is constant, decreased susceptibility of the red cell to while crisis is episodic. In the present sickle with deoxygenation ( p < 0.05). study, red cell filterability and sickling The possibility that these changes are re-with deoxygenation have been measured sponsible for the resolution of crisis is sug-during sickle cell crises. Recovery from gested. S ICKLE CELL DISEASE is a chronic illness punctuated by episodes of crisis. The cause for the occurrence and resolution of these thromboem-bolic episodes is unknown. ’ Some patients have a benign clinical course,23 whereas others have a great morbidity. Many factors have been associated with crises,4’5 but in most crises no precipitating factor can be detected. The inability to relate clinical manifestations to laboratory measurements6 has led to the suggestion that additional intracorpuscular modifying factors or other comple-mentary factorsU223 are needed for crisis to occur. Differences in the susceptibility of red cells to sickle have been recognized,’3’34 but no clinical correlation has been established. Greenberg and Kass’4 men-tioned increased susceptibility of red cells to sickle during crises, but without data, and Charache and Conley’2 observed a correlation between the severity of the clinical manifestations and the changes in viscosity with deoxygenation. The present studies were undertaken to investigate the possibility that spon-taneous sickle cell crises were associated with measurable changes in the proper-ties of the circulating red cell. It was found that (I) recovery from sickle cell crisis correlated with increased filterability of red blood cells as measured by time of filtration and per cent filterable cells under standardized conditions, and (2) recovery from sickle cell crisis was associated with a decreased susceptibility ofcirculating blood cells to sickle