engleski

Development and characteristics of working HBsAg standard: a potential national standard

High sensitivity assays are used on donor blood testing for HBsAg. The quality of blood testing at the national level can be upgraded by using a national HBsAg standard to achieve uniform test sensitivity. Aim of study: To develop a HBsAg standard at a concentration of 0.2 IU/mL, on the model of the British HBsAg standard, stable in liquid state for one year at +4 ºC. The standard should be used as a working standard in blood testing for HBsAg in the Croatian transfusion service. Material and methods: The plasma collected from five HBsAg positive donors was converted to serum by use of thrombin. The sera obtained were filtered in sterile conditions and diluted with distilled water at a 1:4 ratio. The sera were individually and then pooled aa adjusted to a concentration of 100 IU HBsAg by use of PBS-BSA, 5% (preservative 0.05%, Bronidox), according to the method of Ferguson et al. from 2001. A modification of Murex-Abbott HBsAg test, version 3 GE 34/36, was used on plotting calibration curve and determination of HBsAg concentration against WHO International Standard of 100 IU/mL. Results: The stability of HBsAg standard 0.2 IU/mL was assessed for 12 months by use of Murex HBsAg test on automated and semiautomated patient blood testing, yielding an S/CO value of 5.43±0.85. Also, the HBsAg standard 0.2 IU/mL was assessed by the same test on an Ortho Summit Processor analyzer for 6 months, yielding an S/CO value of 4.95±0.67. Single testing of the HBsAg standard 0.2 IU/mL was performed at 27 transfusion medicine laboratories, in 16 of them by use of Axsym Abbott test, in 8 by IMx Abbott test, in 2 by Ortho HBsAg Elisa 3 test, in 1 by Hepanostika Biomerieux test, and in 1 by Abbott Prism HBsAg test. The mean S/CO value was 2.78, 5.3, 8.0, 3.0 and 9, 5 for Axsym, Imx, Ortho, Hepanostika and Prism test, respectively. Conclusion: The HBsAg standard 0.2 IU/mL, developed according to Ferguson et al., is stable in liquid state for at least 12 months at +4 ºC. The HBsAg standard 0.2 IU/mL showed an efficient S/CO ratio of 2-10 with the use of 10 different HBsAg tests, thus meeting the conditions required for a national HBsAg standard.

Croatian HBsAg standard

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