1. ¹National Institute of Biological Standards and Controls, South Mimms, UK
2. ²Biochemistry and Molecular Biology Laboratory ERT MEIDIA, APHM-IFR Jean Roche, Université de la Méditerranée, Marseille, France
3. ³Molecular Pathology, MD Anderson, Houston, TX, USA
4. ⁴Molecular Medicine and Surgery, Karolinska Hospital, Stockholm, Sweden
5. ⁵Molecular Pathology, Institute of Medicine & Veterinary Science, Adelaide, Australia
6. ⁶Hematology and INSERM U728, St Louis Hospital, Paris, France
7. ⁷Pediatric Clinic, University of Milan-Bicocca, Ospedale San Gerardo, Monza, Italy
8. ⁸Hematology, Hospital Clinico Universitario, Salamanca, Spain
9. ⁹Department of Medical & Molecular Genetics, King's College London, London, UK
10. ¹⁰Laboratory Department 931, TYKSLAB, Turku University Hospital, Turku, Finland
11. ¹¹Rheumatology and Hematology, Tohoku University School of Medicine1, Sendai, Japan
12. ¹²Hematology, St James's Hospital, Dublin, Ireland
13. ¹³Molecular Biology, Children's Cancer Research Institute, Vienna, Austria
14. ¹⁴Hematology, Necker Hospital, Paris, France
15. ¹⁵Laboratoire de greffe de Moelle – UMR 5540, University Hospital, Bordeaux, France
16. ¹⁶III Medizinische Klinik, Medizinische Fakultaet Mannheim der Universitaet Heidelberg, Mannheim, Germany
17. ¹⁷Department of Hematology, Aarhus University Hospital, Aarhus, Denmark
18. ¹⁸Hematology, University Hospital, Frankfurt, Germany
19. ¹⁹Clinical and Biological Science, University Hospital, Turin, Italy
20. ²⁰Hematology Oncology, UCLA, Los Angeles, CA, USA
21. ²¹Hematology, Ospedali Riuniti, Bergamo, Italy
22. ²²Immunology, Erasmus, MC University Medical Center Rotterdam, Rotterdam, The Netherlands
23. ²³Specialty Laboratories, Santa Monica, CA, USA
24. ²⁴Foundation for Biomedical Research, Academy of Athens, Athens, Greece

Correspondence: Professor J Gabert, Biochemistry and Molecular Biology Laboratory, IFR Jean Roche, Faculte de Medecine NORD, Bd Pierre Dramard, 13916 Marseille Cedex 20, France. E-mail: jean.gabert@univmed.fr

²⁵Current address: Roche Molecular Systems Inc., Pleasanton, CA 94588, USA

Received 27 January 2006; Revised 14 March 2007; Accepted 22 March 2007; Published online 3 May 2007.

Abstract

Monitoring of BCR-ABL transcripts has become established practice in the management of chronic myeloid leukemia. However, nucleic acid amplification techniques are prone to variations which limit the reliability of real-time quantitative PCR (RQ-PCR) for clinical decision making, highlighting the need for standardization of assays and reporting of minimal residual disease (MRD) data. We evaluated a lyophilized preparation of a leukemic cell line (K562) as a potential quality control reagent. This was found to be relatively stable, yielding comparable respective levels of ABL, GUS and BCR-ABL transcripts as determined by RQ-PCR before and after accelerated degradation experiments as well as following 5 years storage at -20°C. Vials of freeze-dried cells were sent at ambient temperature to 22 laboratories on four continents, with RQ-PCR analyses detecting BCR-ABL transcripts at levels comparable to those observed in primary patient samples. Our results suggest that freeze-dried cells can be used as quality control reagents with a range of analytical instrumentations and could enable the development of urgently needed international standards simulating clinically relevant levels of MRD.