We believe there is a need for a science based quality assurance program in the blood banks and other medical laboratories. We have decided to launch a quality control program under the name bioQControl to test all infectious disease agents. We recognise that previous quality control programs were set up from collaborations between different institutions. Therefore we have asked these parties to join us. We strongly believe in the concept combining data analysis, proficiency testing, validation testing and daily control of performance into one system. The results of a continuous program will be instrumental in redefining the performance of assays and laboratories.
We aim to define nucleic acid standards of the first metrological order; expression in SI units. For your convenience all standards are also defined in IU/ml when a WHO standard is available. Our standard dilutions are used in many validation and quality control studies. As a result the analytical sensitivity of nucleic acid tests is known to us. For qualitative assays, run controls are made available able to control the analytical sensitivity and performance. The viral standards are also used to calibrate infectivity standards expected in 50 % infectious dose. The cross-calibration enables us to estimate residual risk of transmission and/or non-detection. The clinical sensitivity and analytical sensitivity of nucleic acid tests are correlated. We found that current technologies reach theoretical limitations. This finding again demands a need for control on sensitivity.
The serology standards originates from fully seroconverted donors except for HBsAg positive for all antibodies against antigens available on commercial blots. Furthermore the preparations are composed of a large number of plasma samples. They are useful to monitor the analytical sensitivity and consistency but cannot be used to estimate the clinical sensitivity. Clinical sensitivity can be evaluated on seroconversion series and nucleic acid standard dilution series;HIV-Ag, HCV-Ag etc. An exception is HBsAg. Our standard is a purified HBsAg preparation which is inactivated by heat. A dilution is used as WHO standard. Expression in IU/ml is available while expression in ng/ml is on-going
