title: FISHing in the dark: How the combination of FISH and conventional karyotyping improves the diagnostic yield in CpG-stimulated chronic lymphocytic leukemia.
abstract: Despite significant advances in molecular genetic approaches, fluorescence in situ hybridization (FISH) remains the gold standard for the diagnostic evaluation of genomic aberrations in patients with chronic lymphocytic leukemia (CLL). Efforts to improve the diagnostic utility of molecular cytogenetic testing have led to the expansion of the traditional 4-probe CLL FISH panel. Not only do these efforts increase the cost of testing, they remain hindered by the inherent limitations of FISH studies - namely the inability to evaluate genomic changes outside of the targeted loci. While array-based profiling and next generation sequencing (NGS) have critically expanded our understanding of the molecular pathogenesis of CLL, these methodologies are not routinely used by diagnostic laboratories to evaluate copy number changes or the mutational profile of this disease. Mitogenic stimulation of CLL specimens with CpG-oligonucleotide (CpG-ODN) has been identified as a reliable and reproducible means of obtaining a karyotype, facilitating a low-resolution genome-wide analysis. Across a cohort of 1255 CpG-ODN-stimulated CLL specimens, we describe the clinical utility associated with the combinatorial use of FISH and karyotyping. Our testing algorithm achieves a higher diagnostic yield (∼10%) through the detection of complex karyotypes, well-characterized chromosomal aberrations not covered by the traditional CLL FISH panel and through the detection of concurrent secondary malignancies. Moreover, the single cell nature of this approach permits the evaluation of emerging new clinical concepts including clonal dynamics and clonal evolution. This approach can be broadly applied by diagnostic laboratories to improve the utility of traditional and molecular cytogenetic studies of CLL. Am. J. Hematol. 91:978-983, 2016. © 2016 Wiley Periodicals, Inc.
authors.affiliation: Department of Pathology, Brigham and Women's Hospital, Boston, Massachusetts.|Harvard Medical School, Boston, Massachusetts.
authors.forename: Adrian M
authors.initials: AM
authors.lastname: Dubuc
authors.affiliation: Harvard Medical School, Boston, Massachusetts.|Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts.
authors.forename: Matthew S
authors.initials: MS
authors.lastname: Davids
authors.affiliation: Department of Pathology, Brigham and Women's Hospital, Boston, Massachusetts.
authors.forename: Mirela
authors.initials: M
authors.lastname: Pulluqi
authors.affiliation: Department of Pathology, Brigham and Women's Hospital, Boston, Massachusetts.
authors.forename: Olja
authors.initials: O
authors.lastname: Pulluqi
authors.affiliation: Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts.
authors.forename: Kevin
authors.initials: K
authors.lastname: Hoang
authors.affiliation: IBSAL, IBMCC, Centro de Investigación del Cáncer, Universidad de Salamanca-CSIC, Salamanca, 37007, Spain.
authors.forename: Jesus M
authors.initials: JM
authors.lastname: Hernandez-Sánchez
authors.affiliation: Department of Pathology, Brigham and Women's Hospital, Boston, Massachusetts.
authors.forename: Cathy
authors.initials: C
authors.lastname: Schlich
authors.affiliation: IBSAL, IBMCC, Centro de Investigación del Cáncer, Universidad de Salamanca-CSIC, Salamanca, 37007, Spain.|Department of Hematology, Hospital Universitario de Salamanca, Salamanca, 37007, Spain.
authors.forename: Jesus M
authors.initials: JM
authors.lastname: Hernández-Rivas
authors.affiliation: Harvard Medical School, Boston, Massachusetts.|Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts.
authors.forename: Jennifer R
authors.initials: JR
authors.lastname: Brown
authors.affiliation: Department of Pathology, Brigham and Women's Hospital, Boston, Massachusetts. pdalcin@partners.org.|Harvard Medical School, Boston, Massachusetts. pdalcin@partners.org.
authors.forename: Paola
authors.initials: P
authors.lastname: Dal Cin
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002869:Chromosome Aberrations; D002999:Clone Cells / Q000473:pathology; D003582:Cytogenetics; D006801:Humans; D017404:In Situ Hybridization, Fluorescence / Q000379:methods*; D007621:Karyotyping / Q000379:methods*; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000175:diagnosis* / Q000209:etiology / Q000235:genetics; D008875:Middle Aged; D008934:Mitogens / Q000494:pharmacology; D016609:Neoplasms, Second Primary / Q000175:diagnosis; D009838:Oligodeoxyribonucleotides / Q000494:pharmacology; D059010:Single-Cell Analysis; D055815:Young Adult
chemical_list: C408982:CPG-oligonucleotide; D008934:Mitogens; D009838:Oligodeoxyribonucleotides