The diagnostic relevance of red cell rigidity.

Red cell rigidity is an important hemorheological parameter determining the passage of erythrocyte through narrow capillaries and the reduction of blood viscosity under high shear rates. The changes in red cell rigidity in various diseases of altered blood flow - hypertension (HT), diabetes mellitus (DM), myocardial infarction (MI) and cerebrovascular accidents (CVA), using equal sample sizes of 25 each, have been analysed in this paper. One of the essential elements of red cell rigidity is the structural and functional properties of erythrocyte membrane which, in turn, is determined by the membrane biochemistry. Since cholesterol-rich erythrocytes have increased rigidity, the serum cholesterol and triglycerides levels have been monitored in order to detect the extent to which they affect red cell rigidity. No significant change in red cell rigidity have been found in CVA. RBC rigidity is found to be significantly increased in the other diseases. Significant increase in triglyceride levels have been found in all the diseases studied. Cholesterol levels were significantly increased in all diseases except CVA. Hence, increased cholesterol levels have been found to consistently cause a simultaneous increase in RBC rigidity. Triglycerides levels, on the other hand, have not shown a consistent change with changes in RBC rigidity, but have been shown to be a more sensitive marker for early detection of diseased status.