The Statistical Process Control applied to viral Nucleic Acid Testing: an experimental approach.

During the National Multicentric Study concerning the introduction of NAT f or HCV and HIV-1 viruses in blood donation screening which was supervised b y the Medical and Scientific departments of the French Blood Establishment (Etablissement francais du sang - EFS), Transcription-Mediated transcriptio n Amplification (TMA) technology (Chiron / Gen Probe) was experimented in t he Molecular Biology Laboratory of Montpellier, EFS Pyrenees-Mediterranee. After a preliminary phase of qualification of the material and training of the technicians, routine screening of homologous blood and apheresis donati ons using this technology was applied for two months. In order to evaluate the different NAT systems, exhaustive daily operations and data were regist ered. Among these, the luminescence results expressed as RLU of the positiv e and negative calibrators and the associated internal controls were analys ed using Control Charts, Statistical Process Control methods, which allow u s to display rapidly process drift and to anticipate the appearance of inci dents. This study demonstrated the interest of these quality control method s, mainly used for industrial purposes, to follow and to increase the quali ty of any transfusion process. It also showed the difficulties of the post- investigations of uncontrolled sources of variations of a process which was experimental. Such tools are in total accordance with the new version of t he ISO 9000 norms which are particularly focused on the use of adapted indi cators for processes control, and could be extended to other transfusion ac tivities, such as blood collection and component preparation. (C) 2001 Edit ions scientifiques et medicales Elsevier SAS.