Because cyclosporin A rapidly changes its distribution in blood with changes in temperature, sample preparation affects results for it as measured in plasma. If whole blood is stored at either 4 degrees C or room temperature, results for cyclosporin A in the plasma are lower than in whole blood stored at 37 degrees C and centrifuged at this temperature. Re-equilibration of the former to 37 degrees C before cells are removed increases the analytical recovery of cyclosporin A in plasma; the optimal equilibration interval is 30 min. Use of such re-equilibration, followed by immediate centrifugation at room temperature, increases values obtained for cyclosporin in plasma by 60 to 65% over those determined after non-temperature-standardized collection procedures, but does not significantly improve the correlation between values for plasma and whole blood. Hematocrit and concentrations of cyclosporin A in plasma are inversely related. Correction for hematocrit improves the correlation between results for plasma and whole blood.
No takes yet. Share an insight, caveat, or question.
Yatscoff et al. (1984) studied this question.