The failure to devise a satisfactory means of adjusting all sedimentation rates to a standard cell volume, together with a critical analysis of the results of other investigators, casts serious doubt on the validity of any such correction charts.
Two formulae are presented by means of which the sedimentation rate of a given sample of blood can be predicted on the basis of the plasma/cell ratio and plasma proteins concentrations. One formula utilizes the results of saltingout analysis of plasma proteins, the other those of electrophoretic analysis of serum proteins. The most influential factors in determininsg sedimentation rate are plasma/cell ratio, fibrinogen, alpha-2 globulin, and gamma globulin. The results suggest that the effective concentrations of the plasma proteins are most adequately expressed as concentrations per unit of cell volume.
Addition of purified protein fractions (fibrinogen, gamma globulin, and albumin) to the blood in vitro confirm the findings from the statistical studies and suggest a direct cause and effect relationship between the concentration of these proteins and the rate of erythrocyte sedimentation.
Determination of the erythrocyte sedimentation rate cannot give, per se, any clue as to the level of any one of the responsible factors. An appreciation of the multiple factors involved is essential for an adequate interpretation of the clinical significance of a sedimentation rate determination.