Comparison of bone marrow high mitotic index metaphase fluorescence in situ hybridization to peripheral blood and bone marrow real time quantitative polymerase chain reaction on the International Scale for detecting residual disease in chronic myeloid leukemia

• Published in: Haematologica (Roma) 2008-02, Vol.93 (2), p.178-185
• Main Authors: Lundan, Tuija, Juvonen, Vesa, Mueller, Martin C, Mustjoki, Satu, Lakkala, Taina, Kairisto, Veli, Hochhaus, Andreas, Knuutila, Sakari, Porkka, Kimmo
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; Bone Marrow - metabolism; Bone Marrow - pathology; Chromosome aberrations; Female; Follow-Up Studies; Fusion Proteins, bcr-abl - biosynthesis; Fusion Proteins, bcr-abl - genetics; Hematologic and hematopoietic diseases; Humans; In Situ Hybridization, Fluorescence; Leukemia, Myelogenous, Chronic, BCR-ABL Positive - diagnosis; Leukemia, Myelogenous, Chronic, BCR-ABL Positive - drug therapy; Leukemia, Myelogenous, Chronic, BCR-ABL Positive - genetics; Leukemia, Myelogenous, Chronic, BCR-ABL Positive - metabolism; Leukemia, Myelogenous, Chronic, BCR-ABL Positive - pathology; Leukemias. Malignant lymphomas. Malignant reticulosis. Myelofibrosis; Leukocytes, Mononuclear - metabolism; Leukocytes, Mononuclear - pathology; Male; Medical genetics; Medical sciences; Metaphase; Mitotic Index; Neoplasm, Residual; Reverse Transcriptase Polymerase Chain Reaction
• ISSN: 0390-6078; 1592-8721
• DOI: 10.3324/haematol.11910

1 Department of Pathology, Laboratory of Molecular Pathology, Haartman Institute and HUSLAB, Helsinki, Finland; 2 Hematology Research Unit, Biomedicum Helsinki, Helsinki, Finland; 3 Department of Clinical Genetics, University of Oulu and Oulu University Hospital, Oulu, Finland; 4 TYKSLAB, Turku University Hospital Laboratories, Turku, Finland; 5 III. Medizinische Klinik, Medizinische Fakultaet Mannheim der Universitaet Heidelberg, Mannheim, Germany 6 Department of Clinical Chemistry, HUSLAB, Laboratory of Hematology, Helsinki University Central Hospital, Helsinki, Finland; 7 Department of Medical Genetics, University of Turku, Turku, Finland and 8 Department of Medicine, Division of Hematology, Helsinki University Central Hospital, Helsinki, Finland Correspondence: Sakari Knuutila, Laboratory of Molecular Pathology, HUSLAB, Haartmaninkatu 3, PO BOX 400, 00029 Helsinki, Finland. E-mail: sakari.knuutila{at}helsinki.fi Background: Recently, an International Scale was proposed for standardizing BCR-ABL transcript measurements and reporting in the assessment of minimal residual disease by real-time quantitative polymerase chain reaction (RQ-PCR). Here we present the setting up of the International Scale conversion factors for a national laboratory by performing both a cross-analysis of a set of standard samples from a reference laboratory and an analysis of bone marrow and peripheral blood samples at diagnosis (from 32 and 27 patients, respectively). Design and Methods: A total of 222 bone marrow and 173 peripheral blood mononuclear cell samples from 96 patients with chronic myeloid leukemia were analyzed with RQ-PCR according to Europe Against Cancer protocols. Additionally, 291 bone marrow samples were analyzed with high mitotic index metaphase fluorescence in situ hybridization (metaphase FISH). Results: Major molecular response according to the International Scale in BCR-ABL / GUS transcript levels corresponded to a ratio of 0.035% in peripheral blood and 0.034% in bone marrow, yielding the same conversion factor of 2.86 for both types of sample. Based on metaphase FISH, values of 10%/–1.0 log, 1%/–2.0 log and 0.1%/–3.0 log on the International Scale, corresponded to 13%, 2%, and 0.3% of Philadelphia chromosome positive cells in bone marrow, respectively. Conclusions: In conclusion, conversion factors can be determined either by cross-analyzing a number of samples with a laboratory that has already established the International Scale or utilizing sufficient