To compare Elecsys and high performance liquid chromatographytandem mass spectrometric (HPLC-MS/MS) methods in measuring the blood Cyclosporine A (CSA) concentration of bone marrow transplant patients and to investigate the relationship of the results obtained from the two methods in order to establish a more accurate and reasonable conversion method.

The through concentration of CSA in 83 patients with bone marrow transplantation was measured by Elecsys and HPLC-MS/MS, respectively. The results from the two methods were analyzed by linear regression, and by the mean value and the normal distribution analyses in order to investigate the correlation of the two methods. Three data processing methods were performed to carry out weighted residual analysis and to verify the accuracy of the statistical methods.

The mean concentrations of CSA were 139.2 ng/ml and 149.7 ng/ml measured by Elecsys and HPLC-MS/MS methods, respectively. There was no significant difference between Elecsys and HPLC-MS/MS in the determination of CSA concentration (t<0.01, P>0.05). The results obtained by the two methods were in accorded with normal distribution. Linear regression analysis showed that the correlation between the two methods was better (Y=0.888X+ 7.2696, r=0.999). The conversion coefficients obtained by the three data processing methods were 0.89, 0.96 and 0.95, respectively.

The results of the blood CSA concentration in bone marrow transplantation patients obtained by Elecsys and HPLC-MS/MS are similar., and the conversion coefficient of the two methods is not needed. Doctors and clinical pharmacists can directly adjust the individualized dosing of CSA in patients undergoing bone marrow transplantation according to the either testing results.