Combined analysis of morphology and fluorescence in situ hybridization in follow-up of minimal residual disease in a child with Philadelphia-positive acute lymphoblastic leukemia

Measuring response to therapy in AML: Difference from normal flow cytometry vs RQ-PCR

Multiple technologies have been used to monitor response to therapy in acute myeloid leukemia (AML) to improve detection of leukemia over the standard of practice, morphologic counting of blasts. The two techniques most frequently used in a routine clinical setting, flow cytometry and RQ-PCR, differ in their targets, sensitivity, and ability to detect residual disease. Both flow cytometry and RQ-PCR detect the expression of abnormal gene products, at the protein level or RNA level, respectively. Flow cytometry can be applied to a broad range of AML cases while RQ-PCR is limited to specific genetic abnormalities identified in subsets of AML. This article compares the results when both techniques were used in a reference laboratory to monitor AML over the course of treatment, comparing quantitative and qualitative results.

State-of-the-art FISHing: automated analysis of cytogenetic aberrations in interphase nuclei

Interphase fluorescence in situ hybridization (i-FISH) is a powerful tool for visualizing various molecular targets in non-dividing cells. Manual scoring of i-FISH signals is a labor intensive, time-consuming, and error-prone process liable to subjective interpretation. Automated evaluation of signal patterns provides the opportunity to overcome these difficulties. The first report on automated i-FISH analysis has been published 20 years ago and since then several applications have been introduced in the fields of oncology, and prenatal and fertility screening. In this article, we provide an insight into the automated i-FISH analysis including its course, brief history, clinical applications, and advantages and challenges. The lack of guidelines for describing new automated i-FISH methods hampers the precise comparison of performance of various applications published, thus, we make a proposal for a panel of parameters essential to introduce and standardize new applications and reproduce previously described technologies.

Chromosomal numerical aberrations in apparently normal oral mucosa of heavy smokers affected by lung cancer

Cigarette smoke creates a field of injury in the epithelial lining of the entire respiratory tract causing an increased risk for the development of malignant lesions. It is conceivable, therefore, that early genetic alterations, can be detected in oral mucosa of heavy smokers mainly those affected by lung cancer. As aneuploidy was shown to be an early event in oral carcinogenesis, we aimed to investigate the prevalence of aneuploid cells (ACs) in samples obtained from apparently normal looking oral mucosa of heavy smokers affected by lung cancer (LC). Two brush samples were collected from the oral mucosa of 152 subjects; 31 heavy smokers with LC, 59 heavy smokers without LC and 62 never-smokers. The samples were simultaneously analyzed for morphology and fluorescent in situ hybridization (FISH) using chromosomes 2 and 8 centromeric probes. Over 2% ACs were found in 23% of heavy smokers with LC compared to 12% in heavy smokers without LC and 5% of the never-smokers group (P=0.015). A trend was also noticed when comparing the group of heavy smokers without LC with the never-smokers (P=0.198). We conclude that heavy smokers harbour detectable chromosomal numerical aberrations in oral epithelial cells of normal looking mucosa. These aberrations are more frequently found in heavy smokers affected by LC.

Automated scoring of multiprobe FISH in human spermatozoa

In the case of chromosomal aneuploidy in sperm wherein the incident rate is low and a large number of cells require scoring, automated methods that rely on computer software to segment and to count fluorescence signals are particularly necessary due to countless hours spent in reading slides and to the potential for interoperator differences. The purpose of this pilot experiment was to determine whether there were significant differences in the estimates of disomy frequency produced by automated versus manual scoring of signals for chromosome X, Y, and 18 in human sperm. The frequency of X18, Y18, XX18, YY18, and XY18 were determined in four separate normozoospermic samples. Slides were hybridized using a standard sperm FISH protocol for centromere-specific probes. Between 500 and 564, DAPI positive nuclei were captured from each sample and scored using the automated system, and the same slides were scored by a trained cytogeneticist, who was blind to the purpose of the study and the automated system results. None of the estimated frequencies was significantly different between manual and automated methods, regardless of whether individual slides or pooled results across all samples were compared. To our knowledge, this is the first report examining the validity of automated cell scoring in human spermatozoa. The results from this pilot exploration of sperm FISH suggest the comparability between automated and manual methods for estimating sex chromosome disomy and provide evidence that automated laser scanning of multiprobe sperm FISH should be explored further.

Combined morphologic and fluorescence in situ hybridization analysis of voided urine samples for the detection and follow-up of bladder cancer in patients with benign urine cytology

BACKGROUND

Bladder cancer is among the 5 most common malignancies worldwide. Patients with bladder cancer are closely followed with periodic cystoscopies and urine cytology analyses due to the significant risk of tumor recurrence. The UroVysion fluorescence in situ hybridization (FISH) test demonstrated higher sensitivity over urine cytology in detecting bladder cancer by most comparative studies.

METHODS

In the current study, the diagnostic usefulness of a combined cytology and FISH analysis approach was tested using the Duet automatic scanning system in patients with benign urine cytology who were being monitored for recurrent urothelial carcinoma or being assessed for various urologic symptoms.

RESULTS

By combining the benefits of conventional cytology with molecular diagnostics, a more sensitive detection of bladder cancer was attained. All patients who had positive cystoscopy concomitantly with urine sampling were detected by combined analysis. Additional patients that developed transitional cell carcinoma during a follow-up period of 24 months had a previous positive result on combined analysis. Only 2 patients with a negative combined analysis result presented with late disease recurrence (20 months and 22 months, respectively, after the negative test). Therefore, negative combined analysis was found to be predictive of a lack of disease recurrence for at least 12 months. In this timeframe, the overall sensitivity, specificity, negative predictive value (NPV), and positive predictive values of the combined analysis test were 100%, 65%, 100%, and 44%, respectively.

CONCLUSIONS

Given the absolute sensitivity and NPV of the combined analysis test, the management of patients with a negative combined analysis result might be revised and allow for more flexible assessment and management of bladder cancer patients relying more on urine bound tests.

Detection of non-diploid cells in premalignant and malignant oral lesions using combined morphological and FISH analysis - a new method for early detection of suspicious oral lesions

Alteration in DNA content is an early event in oral carcinogenesis. We have examined oral brush samples to detect non-diploid cells (NDC) using simultaneous morphological and cytogenetic analysis. The study included 8 oral squamous cell carcinomas (OSCC), 22 premalignant lesions (OPLs), and 25 control individuals. Slides stained with Giemsa followed by FISH using chromosome 2 centromeric DNA probe, were scanned and fluorescent signals were simultaneously analyzed in parallel with the morphology. The proportion of NDC increased with the severity of the diagnosis. In two control subjects, 1-1.5% of the examined cells were NDC. Over 2% NDC were present in all OSCC cases and in 11 of the OPLs, of which, in 8 the histologic diagnosis was either epithelial hyperplasia or mild dysplasia. A significant number of NDC had normal morphology when cytomorphology and FISH were compared. Two patients with OPLs developed OSCC these patients had a significant proportion of NDC. We suggest that the combined morphological and cytogenetic analysis of cells collected by a non-invasive brush sampling can enhance early detection of potentially malignant cells.

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.

Combined analysis of morphology and fluorescence in situ hybridization significantly increases accuracy of bladder cancer detection in voided urine samples

OBJECTIVES

To evaluate a combined analysis approach that involves cytologic evaluation and fluorescence in situ hybridization analysis for detecting cancer cells in voided urine samples using an automated scanning station.

METHODS

Voided urine samples from 41 patients suspected of having transitional cell carcinoma were stained with May-Grünwald Giemsa stain, scanned for atypical or suspicious cells, destained, and hybridized with a mixture of fluorescent-labeled probes. Samples were tested using either the UroVysion probe or by a mix of chromosomes 3, 7, and 17 centromeric probes. A case was regarded as positive when at least one cell was abnormal in both aspects, morphology and fluorescence in situ hybridization. Patients were evaluated concomitantly by cytology, cytoscopy, and biopsy, if indicated.

RESULTS

Overall, 26 samples were positive by combined analysis. Biopsy-proven transitional cell carcinoma was positive by combined analysis in all cases (100%) and in 13 cases (61.9%) by cytology (P = 0.0133). The advantage of the combined analysis was noted mostly in low-grade and superficial tumors for which the sensitivity of cytology reached 30% (P = 0.023) and 27.27% (P = 0.0133), respectively. Specificity was 100%.

CONCLUSIONS

Our results have shown that combined analysis for the presence of transitional cell carcinoma cells is a powerful tool, providing high sensitivity and specificity, and may offer a new scheme for bladder cancer management.

Philadelphia-chromosome-positive T-lymphoblastic leukemia: acute leukemia or chronic myelogenous leukemia blastic crisis

The Ph1 chromosome has rarely been reported in T-lineage acute lymphoblastic leukemia (T-ALL), and the clinical relevance of this translocation in T-ALL is currently unknown. In chronic myelogenous leukemia (CML) some data indicate derivation of T-cells from the leukemic clone and only a few cases of T-derived blastic crisis have been reported and quite often disputed. Particularly in cases identified initially in blastic crisis it may be difficult to distinguish those from Ph1-positive T-ALL. We herein report 2 patients who presented with a clinical picture of Ph1-positive T-ALL and who raised a differential diagnosis from T-cell blastic crisis of CML. We review the literature and suggest clinical and laboratory features that can help in the diagnosis. According to our literature review, 23 cases of Ph1-positive T-ALL and 44 cases of T-cell blastic crisis of CML, including ours, were reported. Some major differences between the two entities could help in establishing a diagnosis of Ph1-positive T-cell blastic crisis of CML vs. Ph1-positive T-ALL: Male sex and younger age was more predominant in T-ALL. While in most cases of CML blastic crisis there was a history of CML there was no such history in the T-ALL cases. Medullary involvement with lymphoblastic leukemia was present in all cases of T-ALL but only in about half of the cases of CML blastic crisis. None of the CML-blastic crisis cases tested by RT-PCR showed the minor breakpoint transcript, while 2 cases with T-ALL had the minor breakpoint transcript and 1 had both transcripts. Combined morphologic and FISH analysis can help to distinguish between the two entities and was applied in one of our cases. Although both entities carry a severe prognosis, differentiating between them might have clinical relevance, especially in the imatinib era.

Automatic Scanning of Interphase FISH for Prenatal Diagnosis in Uncultured Amniocytes

Fluorescence in situ hybridization (FISH) of uncultured amniocytes using chromosome-specific DNA probes offers the opportunity for rapid aneuploidy screening. Between 80 and 95% of all chromosomal disorders expected in the second trimester of pregnancy can be discovered within 24 hr if DNA probes specific for chromosomes 21, 18, 13, X, and Y are used. Rapid results are crucial for clinical decision-making and are helpful in decreasing the anxiety level in most patients. One of the major factors that have been preventing the rapid FISH test from being broadly incorporated into the clinical setting is the limited staff in the cytogenetics laboratories. The present study demonstrates the use of an automated scanning system (Duet, BioView Ltd. Rehovot, Israel) for analyzing FISH in uncultured amniocytes. Fifty-six amniotic fluid samples were evaluated in parallel by karyotyping, manual FISH analysis, and automatic FISH scanning. Automatic scanning provided accurate results compared to both manual FISH scoring and karyotype analysis. The correlation between automatic and manual FISH scanning was found to be very high (r = 0.9, p < 0.0001). The availability of automation for aneuploidy screening in amniotic fluid samples will enable offering this test to a broader patient population while providing fast and reliable results.

The multiparametric scanning system for evaluation of minimal residual disease in hematological malignancies

Combined simultaneous analysis of morphology, immunophenotyping and fluorescence in situ hybridization on the same cell offers advantages that may help to disclose the relevance of minimal residual disease (MRD) detection. Morphological analysis of small populations of cells related either to malignancy or recipient-associated markers may improve the accuracy of chimerism and MRD testing and delineate their clinical significance.

Tetraploid myeloid cells in donors of peripheral blood stem cells treated with rhG-CSF

Recombinant human granulocyte colony-stimulating factor (rhG-CSF) is frequently used to mobilize CD34+ cells in healthy donors and patient with malignant diseases prior to peripheral blood stem cell (PBSC) harvest. To analyze the effects of rhG-CSF on morphology and genotype of white blood cells, a novel multiparametric cell scanning system that combines morphologic, immune and genotypic analyses of the same cells was used. We report here that tetraploid myeloid cells are present in the peripheral blood of donors treated with rhG-CSF. The tetraploidy was detected in up to 0.6% of differentiated myeloid cells and all observed CD34+ cells were diploid. Thus, short treatment with rhG-CSF of PBSC donors induces numerfical chromosomal alterations in a small subset of mature myeloid cells.