Abstract
The influence of haematocrit on blood cyclosporin measurements has been studied in 276 paired blood and plasma samples from 21 renal transplant patients. A highly significant correlation was found between blood and plasma cyclosporin concentrations, r = 0.8744, but the correlation between blood or plasma cyclosporin and haematocrit was not significant. The ratio of blood/plasma cyclosporin did not significantly increase with increasing haematocrit. It was concluded that in vivo the influence of haematocrit on the measurement of blood cyclosporin concentrations was negligible.