ERYTHROCYTE SEDIMENTATION IN COLUMNS AND THE SIGNIFICANCE OF ESR

Erythrocyte Sedimentation Rate (ESR) is a simple, non-specific clinica l test, Most models of erythrocyte sedimentation (ES) are formulated a s a sigmoid function but consider the ES process to consist of three d istinct phases: single-cell fall; fall of rouleaux and aggregates; cel l packing, Recently, a piecewise (three-phase) continuous model has be en developed, Our study applies ES data from 29 haematologically norma l subjects to this model and re-evaluates the mechanism of ES using th e derived model parameters, Using the Westergren technique, ES reading s were taken every 10 minutes for 300 minutes, Three subjects remained in the first phase, while 26 displayed three discrete phases, For the 26 subjects, the average rate of fall of the sedimenting particles in the first phase was 87 mu m/min, while that of the second phase was 1 76 mu m/min. The ratio of these two values suggests an alternative nat ure of sedimenting particles in the first phase, Further, the average duration of the first phase was 62 minutes, suggesting that, in 50% of subjects, aggregate formation is incomplete when ESR is measured at 6 0 minutes. Copyright (C) 1997 Elsevier Science Ltd.