Objective: It has been proposed that the homocysteine (Hcy) produced during the metabolism of methionine plays a role in etiopathogenesis of several diseases. The interest in measurement of plasma Hcy levels has increased recently upon the finding that Hcy is an independent risk factor for cerebral, vascular and coronary artery diseases.

Materials and Methods: In the present study, we measured plasma Hcy levels with two different systems; Chromsystems kits in HP1100 and Drew DS30 and investigated the analytical performances of these two systems in Hcy measurements in clinical laboratories.

Results: Reproducibilities for Drew DS30 system and HPLC with Chromsystems kits were found to be 2.1 and 1.6%, respectively (p=0.043). Inter-assay variability for three different Hyc concentrations revealed standard deviations of 4.9 and 4.0% for low (5 µmol/L), 5.2 and 4.2% for moderate (12.5 µmol/L) and 5.8 and 4.2% for high (24.8 µmol/L) concentrations for Drew DS30 and HPLC with Chromsystems kits, respectively. Mean recovery was 101.8 ± 2.3% for Drew DS30 and 98.9 ± 1.4% for HPLC. The lowest measurable Hcy concentrations for Drew DS30 and HPLC systems were recorded as 2.8 and 1.6 µmol/L, respectively. There was a good correlation between the Hyc levels measured with both systems (r= 0.948). Limits of linearity were found to be 100 and 200 µmol/L for Drew DS30 system and HPLC with Chromsystems kits.

Conclusion: We demonstrated that the use of Chromsystems HPLC for homocysteine measurement might be more useful both in groups with predicted hyperhomocysteinemia and in laboratories with high number of patients where there are limitations in sample amounts, and working hours. On the other hand, in laboratories without the limitations mentioned above, DS30 system might be used with a similar performance to Chromsystems kits.