INTRODUCTIONSince undetectable BCR-ABL mRNA transcription does not always indicate eradication of the Ph+ CML clone and since transcriptionally silent Ph+ CML cells exist, quantitation by genomic PCR of bcr-abl genes can be clinically useful. Furthermore, hotspot mutations in the Abelson tyrosine kinase (ABLK) domain of the bcr-abl gene translocation in Philadelphia chromosome-positive (Ph+) chronic myeloid leukaemia (CML) cells confer resistance on the specific kinase blocking agent, STI571.

MATERIALS AND METHODSGenomic DNA from K562, CESS and patient CML cells were amplified using rapid cycle quantitative real-time polymerase chain reaction for the gene regions spanning the mutation hotspots. In assays for ABLK exons 4 or 6, exonic or intronic PCR primers were used.

RESULTSWe show that separation of cycle threshold (CT) values for log-fold amplicon quantification was 2.9 cycles for ABLK exon 4, and 3.8 cycles for exon 6 with rapid amplification times. K562 CML cells were found to have a approximately 2 log-fold ABLK gene amplification. In contrast, patient CML cells had CT differences of 2.2 for both exon, suggesting that there was no significant ABLK gene amplification. DNA sequencing confirmed that neither K562 nor patient CML cells contained ABLK hotspot mutations. Messenger RNA transcription analysis permitted the assessment of BCR-ABL transcription, which was qualitatively correlated to genomic amplification.

CONCLUSIONSThis novel Q-PCR assay was found to have high fidelity and legitimacy, and potentially useful for monitoring minimal residual disease, transcriptionally silent Ph+ CML cells, and bcr-abl gene amplification.

Chronic Disease ; Drug Resistance ; genetics ; Fusion Proteins, bcr-abl ; genetics ; Gene Amplification ; Genes, abl ; genetics ; Hematologic Neoplasms ; genetics ; Humans ; Leukemia, Myeloid ; genetics ; Mutation ; Protein-Tyrosine Kinases ; genetics ; RNA, Messenger ; Reverse Transcriptase Polymerase Chain Reaction

INTRODUCTIONHigh workload volumes in a Cytogenetics laboratory can lead to long result turn-around times (TAT). This study aimed to improve laboratory efficiency by adopting Lean Management System initiatives to increase productivity through the elimination of wastes. This study examined if the prerequisite 20-cell analysis was sufficient for a conclusive result or if additional cell workup was necessary to ascertain the presence of a previous chromosome abnormality among cases on follow-up, or when a single abnormal cell was encountered during the analysis to determine the presence of a clone.

MATERIALS AND METHODSThe karyotype results of cases that had additional workup were retrieved from among 8040 bone marrow cases of various haematological disorders performed between June 2003 and June 2008.

RESULTSOf 8040 cases analysed, 2915 cases (36.3%) had additional cell workup. Only 49 cases (1.7%) led to the establishment of a clone. The majority of these cases could have been resolved without the additional workup, especially if fluorescence in situ hybridization (FISH) or polymerase chain reaction (PCR)-based assays had been utilised.

CONCLUSIONThis study shows that the additional workup procedure is redundant. The time saved by discontinuing the workup procedure can be used to analyse other cases, leading to increased laboratory efficiency and a faster TAT without compromise to patient care. The practice of additional workup over and above the 20- cell analysis should be dispensed with as little benefit was derived for the amount of additional manpower expended. FISH or PCR-based assays should be utilised to elucidate a case further.

Adult ; Aged ; Aged, 80 and over ; Bone Marrow ; Bone Marrow Cells ; Cytogenetics ; Efficiency ; Efficiency, Organizational ; Female ; Hematologic Diseases ; diagnosis ; pathology ; Humans ; In Situ Hybridization, Fluorescence ; instrumentation ; methods ; Karyotyping ; instrumentation ; methods ; Male ; Polymerase Chain Reaction