Automated detection of residual leukemic cells by consecutive immunolabeling for CD10 and fluorescence in situ hybridization for ETV6/RUNX1 rearrangement in childhood acute lymphoblastic leukemia.
Among the various methods available for analyzing minimal residual disease, a new procedure for the cell-based approaches using consecutive phenotypic and genotypic analysis as revealed by immunofluorescent labeling and subsequent fluorescent in situ hybridization (FISH) has been developed. We are introducing a fluorescent microscopy-based technique by which not only cellular targets and immunological marker positivity, but also the FISH pattern was identified by automated scanning. For the latter one translocation-specific FISH pattern recognition was accomplished by using an automated scanning mode for the 3D determination of valid distances between FISH signals, to define the cutoff value for the shortest green-red spot distance differentiating positive cells from negative ones. The procedure was tested with CD10(+) acute lymphoblastic leukemia cell line harboring the t(12;21)(p13;q22) resulting in the ETV6/RUNX1 rearrangement (formerly TEL/AML1), as well as peripheral blood lymphocytes of healthy individuals. Using the combined, automated method, a sensitivity of 98.67% and a specificity of 99.97% were obtained. The mean false positivity + 2 standard deviations cutoff level (0.09%) allows detection of leukemic cells with high accuracy, even a bit below the tumor load dilution of 10(-3), a value reported to be critical in clinical decision making.
Alpár
Donát
D
Department of Pathology, Faculty of Medicine, University of Pécs, 12. Szigeti Str., H-7624, Pécs, Hungary.
Kajtár
Béla
B
Kneif
Mária
M
Jáksó
Pál
P
László
Renáta
R
Kereskai
László
L
Pajor
László
L
D000328:Adult; D045744:Cell Line, Tumor; D002648:Child; D050676:Core Binding Factor Alpha 2 Subunit / Q000235:genetics*; D005434:Flow Cytometry / Q000379:methods; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D017404:In Situ Hybridization, Fluorescence / Q000379:methods; D008856:Microscopy, Fluorescence / Q000379:methods*; D018365:Neoplasm, Residual / Q000175:diagnosis* / Q000235:genetics / Q000378:metabolism; D015260:Neprilysin / Q000032:analysis*; D015514:Oncogene Proteins, Fusion / Q000235:genetics*; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000175:diagnosis* / Q000235:genetics / Q000378:metabolism; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D000097764:ETS Translocation Variant 6 Protein
D050676:Core Binding Factor Alpha 2 Subunit; D015260:Neprilysin; D015514:Oncogene Proteins, Fusion; C102421:TEL-AML1 fusion protein; D000097764:ETS Translocation Variant 6 Protein