Decreased deformability of red cells in refractory anemia and the abnormality of the membrane skeleton.

Rheological characteristics of red cells in two patients with refractory anemia (with single chromosomal abnormality of 20q- or 13q-, respectively) were investigated with the hematological and biochemical properties. (1) Whole blood viscosity was remarkably increased, and the red cell deformability was greatly impaired (the impairments were prominent in patient with 20q-). (2) The hematocrit of both patients was about half of the normal value. Remarkable anisocytosis with elliptocytes and poikilocytes was observed in the patient with 20q-, but the anisocytosis was not so prominent in the patient with 13q-. (3) 2,3-diphosphoglycerate content in red cells was markedly increased in both patients, but adenylate content was not. (4) The red cells were slightly resistant to osmotic hemolysis, but they were not heat-labile. (5) Structural abnormality of spectrin was suggested from the impaired dimer-dimer association in red cell membrane and from the different susceptibility of spectrin to tryptic digestion. In conclusion, the rheological impairments and the abnormal shape of red cells in refractory anemia probably originated from the structural abnormality of cytoskeletal proteins in membrane, and the functional and structural abnormality may be different among patients.