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Comparison of molecular and cytogenetic methods in the evaluation of engraftment following allogeneic bone marrow transplantation.

Cytogenetic evaluation of patients after bone marrow transplantation (BMT) has provided a standard method of documentation of hematopoietic engraftment. More recently, recombinant DNA technology has also been applied to determine engraftment status. In order to establish the relative utility of these methods in clinical practice we have directly compared the data from cytogenetic and recombinant DNA methods, evaluating engraftment status in 68 BMT recipients. Patients were evaluated pre-transplant, 30, 60, 90, and 180 days after BMT, and yearly thereafter for 1) the presence or absence of the Y chromosome in sex-mismatched allogeneic transplant recipients, 2) the presence or absence of the Philadelphia chromosome [t(9;22)] in patients transplanted for chronic myelogenous leukemia (CML), 3) restriction fragment length polymorphism (RFLP) profiles, and/or 4) clonal rearrangement of the bcr gene. Cytogenetic examination of unstimulated bone marrow and recombinant DNA tests of nucleated peripheral blood or bone marrow cells produce qualitatively similar data in the identification of patient and donor cells and/or normal and tumor cells. Differences in the results obtained by the two analytic methods were most often due to the restricted cell populations evaluable by cytogenetic studies of PHA-stimulated peripheral blood specimens. DNA analyses could frequently be applied at earlier intervals after transplantation and, in cases of graft rejection, when cell counts were low. Although recombinant DNA methods required fewer cells and demonstrated greater sensitivity in detection of minor cell populations in the majority of instances, the cytogenetic evaluation may complement the DNA studies and allow detection of additional chromosomal anomalies.

Bone Marrow Transplantation↗

Relevance of cytogenetic and fluorescent in situ hybridization analyses in the clinical assessment of soft tissue sarcoma.

Soft tissue sarcomas are a heterogeneous group of malignant tumors displaying a wide range of clinical presentations, morphological features, and biological behaviors. These characteristics and the recent development of differentiated treatment regimens for the different types of soft tissue sarcomas call for refined histological classification using additional ancillary approaches such as cytogenetic and molecular genetic analyses. We coupled classical cytogenetics and fluorescent in situ hybridization (FISH) on both metaphases and interphase nuclei to show the feasibility of this approach to characterize tumor type-specific chromosome rearrangements in soft tissue sarcomas of different histotype. In 35 cases analyzed, we detected the presence of specific chromosome rearrangements such as t(X;18) in synovial sarcoma (SS), t(12;16) in myxoid liposarcoma (MLS), t(11;22) in peripheral primitive neuroectodermal tumors (pPNET), t(2;13) in alveolar rhabdomyosarcoma (ARMS) and ring chromosomes in dermatofibrosarcoma protuberans (DFSP). In several cases, the presence of these cytogenetic rearrangements was of help for a differential diagnosis. The FISH analysis using painting probes not only confirmed the cytogenetic results but also allowed the identification of tumor-specific chromosome changes in those cases presenting low mitotic index or with poor quality chromosomes. Moreover, in the absence of analysable metaphases, FISH was successfully performed on interphase nuclei. Taken together, these results indicate both the diagnostic and clinical relevance of a molecular cytogenetic analysis in the study of soft tissue sarcomas.

Biomarkers, Tumor↗

Good prognosis cytogenetics in B-cell chronic lymphocytic leukemia is associated in vitro with low susceptibility to apoptosis and enhanced immunogenicity.

Chromosomal abnormalities in B-cell chronic lymphocytic leukemia (B-CLL) have been shown to correlate with prognosis. Little is known about the relationship between chromosomal abnormalities and biological behavior of B-CLL cells in vitro. The present study was designed to explore the impact of chromosomal abnormalities determined by interphase fluorescence in situ hybridization (FISH) on the in vitro survival and immunogenicity of B-CLL. Considerable heterogeneity was noted in the in vitro survival and expression of costimulatory, adhesion, and antigen-presenting molecules by B-CLL cells. Spontaneous apoptosis of B-CLL cells in vitro was significantly lower in samples with good prognosis cytogenetics when compared to samples with poor prognosis cytogenetics. In contrast, B-CLL cells from samples with good prognosis cytogenetics exhibited higher basal expression of molecules involved in costimulation, cellular adhesion, and antigen presentation, and induced significantly more T-cell proliferation in mixed lymphocyte cultures. We conclude that chromosomal aberrations of B-CLL cells correlate with the in vitro biological behavior of B-CLL. Our data indicate that good prognosis cytogenetics correlates with less spontaneous apoptosis but greater in vitro immunogenicity. These findings could have significant implications on the design of future therapeutic approaches in patients with CLL, and the likelihood of response based on cytogenetics.

Aged↗

Combination of broad molecular screening and cytogenetic analysis for genetic risk assignment and diagnosis in patients with acute leukemia.

We evaluated the impact of genetic analysis combining cytogenetics and broad molecular screening on leukemia diagnosis according to World Health Organization (WHO) and on genetic risk assignment. A two-step nested multiplex RT-PCR assay was used that allowed the detection of 29 fusion transcripts. A total of 186 patients (104 males (56%), 174 adults (94%), 12 children (6%), 155 AML (83%), 31 ALL (17%)) characterized by morphology and immunophenotyping were included. Of these 186 patients, 120 (65%) had a genetic abnormality. Molecular typing revealed a fusion transcript in 49 (26%) patients and cytogenetic analysis revealed an abnormal karyotype in 119 (64%). A total of 27 (14%) cases were genetically classified as favorable, 107 (58%) intermediate and 52 (28%) unfavorable. For 38 (20%) patients, there was a discrepancy in the genetic risk assignments obtained from broad molecular screening and cytogenetics. Cryptic fusion transcripts in nine (5%) patients changed the genetic risk assignment in four and the WHO classification in four patients. In 34 patients (18%), cytogenetics defined the risk assignment by revealing structural and numerical chromosomal abnormalities not detected by molecular screening. Broad molecular screening and cytogenetics are complementary in the diagnosis and genetic risk assignment of acute leukemia.

Acute Disease↗

Proteomics of acute myeloid leukaemia: Cytogenetic risk groups differ specifically in their proteome, interactome and post-translational protein modifications.

Acute myeloid leukaemia (AML) is characterized by specific cytogenetic aberrations that are strong determinants of prognostic outcome and therapeutic response. Because the pathological outcome of AML patients with cytogenetic abnormalities differs considerably, we hypothesized that their proteome may also differ specifically in their expression pattern, protein interaction pathways and post-translational modifications (PTM). We performed this study using 42 AML patients diagnosed for various cytogenetic abnormalities based on two-dimensional gel electrophoresis and matrix-assisted laser desorption/ionization time of flight mass spectrometry (MS) and MSMS tandem MS. We could identify significant differences in the proteome and PTM of peptides, later confirmed by other methods, between cytogenetic groups. The interactome analysis based on computational bioinformatics reveals major regulating networks: MAPK8 and MYC for complex aberrant karyotype, TP53 for t(8;21), TP53-MYC-PRKAC for 11q23 and JUN and MYC for Inv(16). Further, we analysed 42 MS spectra representative of hnRNPH1, calreticulin and hnRNPA2/B1 in a peak explorer, which reveals a cytogenetic-specific PTM of beta-O-linked N-acetyl glucosamine (O-GlcNAc) of hnRNPH1 in AML patients with 11q23 translocation, an acetylation of calreticulin in t(8;21) translocation and methylation of hnRNPA2/B1 in patients with translocations of t(8;21) and inv(16). This report may lead to a new thinking about AML pathogenesis, as differences at PTM level could be used to distinguish different subtypes of AML.

Cell Shape↗

Underestimation of inversion (16) in acute myeloid leukaemia using standard cytogenetics as compared with polymerase chain reaction: results of a prospective investigation.

In order to determine whether the polymerase chain reaction (PCR) is more suitable for the detection of inversion (16) as compared with standard cytogenetics, we prospectively investigated a total of 132 cases of de novo acute myeloid leukaemia (AML) (n = 121) and secondary AML after myelodysplastic syndromes (MDS) (n = 11) using a sensitive and nested PCR procedure to detect the fusion transcripts CBFbeta-MYH11. All patients were recruited within 10 months in an ongoing multicentre AML-trial. In addition, several cases from a retrospective molecular analysis were included. The data were compared with standard cytogenetics performed in a central laboratory. Of the 132 prospective AML cases, five patients (3.7%) harboured inv(16) upon conventional cytogenetics. In all cases fusion transcripts CBFbeta-MYH11 were detected using PCR. In addition in two patients fusion transcripts were detected, although cytogenetics revealed a normal karyotype. In the group of patients analysed retrospectively, four patients harboured fusion transcripts specific for CBFbeta-MYH11; cytogenetics were normal in one case, and could not be evaluated in two cases. These data show that PCR may be a better means to detect inv(16) in AML. Since inv(16) may have prognostic impact in AML, detection of this aberration seems important in the clinical management of AML patients.

Acute Disease↗

CD40L stimulation enhances the ability of conventional metaphase cytogenetics to detect chromosome aberrations in B-cell chronic lymphocytic leukaemia cells.

Conventional metaphase cytogenetics underestimates the frequency of specific chromosome aberrations in B-cell chronic lymphocytic leukaemia (B-CLL) as a result of the very low proliferative activity of these cells in vitro. New molecular approaches, such as fluorescence in situ hybridization (FISH) or comparative genomic hybridization (CGH), may circumvent this problem, at least in part, but these techniques are either strongly dependent on the knowledge of candidate regions or detect only unbalanced aberrations. In the present study, we analysed 27 B-CLL peripheral blood samples by metaphase cytogenetics after CD40 ligand (CD40L)-induced cell cycle stimulation. In comparison with the simultaneous use of B-cell mitogens such as 12-O-tetradecanoylphorbol-13-acetate (TPA), lipopolysaccharide (LPS) and pokeweed mitogen (PWM), CD40L stimulation of B-CLL cells induced a threefold increase in metaphases amenable to analysis by conventional cytogenetics. The analysis of these metaphases confirmed all genetic abnormalities detected by FISH. Moreover, CD40L-enhanced cytogenetics revealed complex karyotypic aberrations in 11 out of 27 patients (41%). In one case, a balanced translocation t(11;16)(p15;p13.1), so far unreported in B-CLL, was detected. Taken together, the results of our study show the potential of CD40L-enhanced metaphase cytogenetics to detect more and new chromosome aberrations in B-CLL.

3T3 Cells↗

Immunophenotypic and cytogenetic changes in acute leukaemia at relapse.

To gain more insight into the immunophenotypic and cytogenetic changes in acute leukaemia at relapse, 99 Korean patients treated at a single institution were studied: acute myelogenous leukaemia (AML, n=46), acute lymphoblastic leukaemia (ALL, n=44) and biphenotypic and mixed leukaemia (n=9). Immunophenotypic changes at relapse were observed in 51 of 99 patients (51.5%) with almost even distribution in AML and ALL. Overall expression of aberrant markers on leukaemic cells was more frequent at relapse than at initial diagnosis (P < 0.05), and this finding was most prominent in B lineage ALL (41.4% versus 10.3%, P=0.007). Gain of aberrant CD13 or CD33 at relapse of B lineage ALL was most frequently observed. Cytogenetic changes at relapse were observed in 28 of 46 patients (60.8%). The initially abnormal karyotypes were more frequently associated with clonal changes at relapse compared to initially normal karyotypes (78.3% versus 43.5%, P=0.016). Cytogenetic changes were more frequent in B lineage ALL than in AML (90% versus 47.8%, P=0.05). In ALL, patients showing cytogenetic changes at relapse were significantly younger than those showing no changes (mean age of 15.0 versus 38.8, P=0.002), whereas in AML there was no significant difference between the two groups. In conclusion, the gain of aberrant markers and cytogenetic changes at relapse, which are suggestive of clonal instability, are more prevalent in B lineage ALL compared to AML, and lymphoid leukaemic cells of younger patients are more susceptible to clonal changes at relapse.

Acute Disease↗

A precise and scalable method for querying genes in chromosomal banding regions based on cytogenetic annotations.

MOTIVATION: Staining the human metaphase chromosomes reveals characteristic banding patterns known as cytogenetic bands or cytobands. Using technologies based on metaphase chromosomes, researchers have accumulated much knowledge about the correlations between human diseases and specific cytoband aberrations, indicating the presence of disease-associated genes in those bands. With the progress of human genome project and techniques such as fluorescent in situ hybridization, many genes have been assigned to the cytobands and annotated in public databases, making it possible to find all genes in the disease-related cytobands through database queries. However, finding genes in cytobands remains an imprecise process, partly due to the insufficiency of current methods for cytoband queries, especially for those based on cytogenetic annotations. RESULTS: By transforming the cytoband annotations into numerical segments, a new query method is developed that is able to accurately define any cytogenetic ranges in human chromosomes. A query system (designated cytoband query sys CQS) is implemented using cytogenetic annotations in the public domain. Judged by a performance test, CQS executed as accurately as expected using cytogenetic annotations from NCBI Map Viewer. The new method is scalable and can be applied to genomes from other species. AVAILABILITY: The CQS is freely accessible over the Internet at http://moris.csie.ncku.edu.tw/cqs/ CONTACT: clh9@mail.ncku.edu.tw SUPPLEMENTARY INFORMATION: http://moris.csie.ncku.edu.tw/cqs/

Algorithms↗

The incidence peaks of the childhood acute leukemias reflect specific cytogenetic aberrations.

The correlation between age and karyotype was studied in 1425, 0 to 14.9 years old children who were diagnosed with acute lymphoblastic leukemia (ALL) or acute myeloblastic leukemia. Almost 80% of the non-Down B-cell precursor ALL cases in the 2 to 7 years frequency peak group who had aberrant cytogenetic results had either a high-hyperdiploid clone (51 to 61 chromosomes) or a translocation t(12;21)(p13;q22). Among B-cell precursor ALL cases, high white blood cell counts correlated with earlier age at diagnosis (rS=-0.23; P<0.001) being most evident for 11q23/MLL-aberrations, translocation t(12;21)(p13;q22), and high-hyperdiploidy. Among acute myeloblastic leukemia patients, frequency peaks were found for those with MLL/11q23 rearrangements (peak: first year), Down syndrome (peak: second to third year), or cytogenetic abnormalities other than translocations t(8;21), t(15;17), and inv(16)/t(16;16) (peak: first to third year). The epidemiology of the cytogenetic subsets of acute leukemias questions whether age as a disease-related prognostic parameter has any relevance in childhood leukemia clinical research beyond being a surrogate marker for more important, truly biologic features such as cytogenetic aberrations and white cell count at diagnosis. Further research is needed to explore whether the 2 to 7 years age incidence peak in childhood ALL harbor yet unidentified cytogenetic subsets with the same natural history as the high-hyperdiploid and t(12;21)-positive leukemias.

Adolescent↗

Clinical and cytogenetic survey of institutionalized mentally retarded patients with emphasis on the fragile-X syndrome.

A detailed clinical and cytogenetic survey for the fragile-X syndrome was undertaken on 201 institutionalized mentally retarded males with no previously recognized cause of retardation, and the causes of mental retardation were summarized from a total of 595 institutionalized male and female patients after the review of their medical records including clinical and cytogenetic data. Among the 201 males clinically and cytogenetically examined, five (2.5%) had abnormal chromosome findings with four (2%) having the fragile-X syndrome. Twelve of the males (6.0%) were diagnosed with a single gene disorder. In the present study, mental retardation was classified as possibly due to multifactorial causes when a genetic syndrome, chromosome abnormality or environmental insult was not identified, but mental retardation was present in one or more first and/or second degree relatives, but did not follow a recognizable inheritance pattern. Hence, mental retardation was recorded in other family members and may indicate possible multifactorial causes in 45 males (22.4%). An environmental insult was noted in 25 males (12.4%); unexplained birth defects in three males (1.5%); a specific condition or diagnosis identified, but cause unknown (e.g. Rubinstein-Taybi syndrome) in 10 males (5%); and no diagnosis made in the remaining 101 males (50.2%). Of all 595 patients (334 males and 261 females), including the 201 males who had undergone a detailed clinical and cytogenetic evaluation, 39 (6.6%) had abnormal chromosome findings, with Down's syndrome noted in 31 of the patients. Twenty-five patients (4.2%) were diagnosed with a single gene disorder while mental retardation was noted in other family members and may indicate possible multifactorial causes in 64 patients (10.8%). An environmental insult was noted in 170 patients (28.6%); unexplained birth defects in 17 patients (2.9%); a specific condition or diagnosis but cause unknown in 27 patients (4.5%); and no diagnosis made in 253 patients (42.5%). Clinical and cytogenetic screening of mentally retarded patients for the fragile-X syndrome and other causes of mental retardation is helpful in identifying individuals and their families who may benefit from genetic services such as counseling and treatment. This study was performed over an approximate 2 year period from 1987 to 1989.

Adolescent↗

Is cytogenetic diagnosis of 46,XX karyotype spontaneous abortion specimens erroneous? Fluorescence in situ hybridization as a confirmatory technique.

AIM: Performing the standard cytogenetic technique on spontaneous abortion material is still a valuable tool, but finding a normal 46,XX karyotype can confuse investigators and lead to a problem in diagnosis. This is mainly because it is possible for the female or male conceptus to retain contaminating maternal cells. To address this possibility, we used fluorescence in situ hybridization technique (FISH). X (DXZ1: p11.1-q11.1 region) and Y (DYZ3: p11.1-q11.1 region) chromosome alpha-satellite probes were employed to confirm the karyotypes previously diagnosed as 46,XX by our cytogenetic laboratory, or to verify the occurrence of 'Y chromosome component'. METHODS: Besides conventional long-term tissue cultures and G-bands by trypsin using Giemsa (GTG) bandings, FISH analyses were also performed. RESULTS: A total of 134 spontaneous abortion specimens (singleton gestations) were referred for cytogenetic evaluation, of which 125 specimens were successfully karyotyped. Of these, 20.8% (26/125) had chromosome aberrations; 88.5% (23/26) of these aberrations were numerical and 11.5% (3/26) were structural. The most prevalent numerical anomalies were trisomies 15, 16 and 21, tetraploidies, triploidies and monosomy X. FISH results were obtained for 45 out of 92 cases with 46,XX, of which 2 (4.4%) showed XY signals. CONCLUSIONS: For accurate cytogenetic evaluation of spontaneous abortion materials, an additional technique such as FISH is required in order to confirm the cytogenetic results or to provide an estimate of the error rate in the analysis of miscarriages.

Abortion, Spontaneous↗

Cytogenetic analysis in 941 consecutive patients with haematologic disorders.

Clinical and cytogenetic findings were reevaluated in 941 consecutive patients with suspected neoplastic haematological conditions studied during 1973-1984. A total of 1652 attempts at cytogenetic analysis with banding technique were performed in 240 patients with acute nonlymphocytic leukaemia (ANLL), 177 with chronic myeloid leukaemia (CML), 157 with myelodysplasia (MDS), 82 with myeloproliferative disorders (MPD), 114 with acute lymphoblastic leukaemia (ALL), 42 with non-Hodgkin lymphoma or other lymphoproliferative disorders (NHL + LPD), and 120 patients with benign disorders. Only 1 patient with a benign disorder had an acquired clonal chromosomal abnormality (diagnostic specificity 0.99), whereas abnormalities were detected in 50.0% of patients with malignant haematologic disorders (diagnostic sensitivity 0.50). Success rate was 73-74.4% in ALL, MPD, and NHL + LPD, versus 87-94% in ANLL, MDS, CML, and benign disorders. The frequencies of detected abnormalities in diagnostic subgroups were within the limits of previous reports. Striking differences in cytogenetic pattern in relation to age were found in MDS and ANLL. Results from 1973-80 were compared to 1981-84. In spite of a marked reduction in failure rate of bone marrow (BM) analyses in the second time period, the fraction of patients with only inadequate cytogenetic analyses and the frequencies of detected chromosome abnormalities remained essentially unchanged. Peripheral blood samples had a high failure rate, and seldom provided additional information to BM analyses. Delay in transportation time of samples did not in general affect the outcome of cytogenetic analysis, with possible exceptions for a higher failure rate in ALL and lower frequency of detected abnormalities in ANLL.

Acute Disease↗

Cytogenetics of secondary myelodysplasia (sMDS) and acute nonlymphocytic leukemia (sANLL).

76 cases of secondary myelodysplasia (sMDS) and acute non-lymphocytic leukemia (sANLL) were cytogenetically analyzed. Among the 36 sMDS patients, 13 (36%) had only normal karyotypes whereas 23 (64%) displayed clonal chromosomal abnormalities. The most common aberrations were -7, 5q-, -5, and +8. In 10 patients (43% of the cytogenetically aberrant cases), clones with only one anomaly, mostly 5q- or -7, were found. Of the 40 sANLL patients, normal karyotypes were detected in 10 (25%). Among the 30 (75%) abnormal cases, the most frequent aberrations were -7, -5, +8, 7q-, -17, and +21. 12 patients (40%) had clones with single abnormalities, most often -7. In 4 sANLL patients cytogenetically unrelated clones were detected. A survey of all previously published secondary hematologic neoplasias reveals that the most frequent abnormalities in sMDS are -7 (41%), 5q- (28%), and -5 (11%), followed by der(21q), +8, 7q-, der(12p), t(1;7), -12, -17, der(17p), der(3p), der(6p), and -18. Clones with single aberrations have been found in 45% of the cases and cytogenetically unrelated clones have been described in 6%. The most common abnormalities in sANLL are -7 (38%), 5q- (17%), -5 (15%), +8 (13%), and -17 (11%), followed by der(3q), der(11q), der(12p), -21, 7q-, -18, der(3p), der(17p), +21, der(21q), der(6p), and -16. 38% of the sANLL patients have had clones with only one aberration and 3% have had unrelated clones. The frequencies of these nonrandom abnormalities in sMDS and sANLL are thus remarkably similar - the only exception appears to be 5q-, which is more common in sMDS. Also the mean number of abnormalities per case is similar - 5.3 in sMDS and 5.6 in sANLL. When the incidences of characteristic cytogenetic abnormalities were correlated with the type of previous therapy, -7 was found to be more frequent in sMDS and sANLL patients who had been exposed to chemotherapy whereas 5q- was associated with previous exposure to ionizing radiation in sMDS patients.

Aged↗

Clarification of dubious karyotypes in Hodgkin's disease by simultaneous fluorescence immunophenotyping and interphase cytogenetics (FICTION).

Cytogenetic studies on Hodgkin's disease (HD) typically reveal very complex karyotypes with a variety of numerical and structural abnormalities. The confusing thing is that about 10% of cases contain relatively discrete chromosome aberrations, for example a simple trisomy or loss of one single chromosome. Whether these karyotypes really correspond to Hodgkin and Reed-Sternberg (HRS) cells is uncertain. They could, for example, represent early stages in the evolution of the karyotype of the pathognomonic HRS cells. On the other hand, they could be artificial events that occur during the cytogenetic procedure. In our experience, isolated loss of the Y chromosome is the most frequent finding of this type. This aberration is usually considered to be a preparation artifact. However, if one takes into account that in HD up to 50% of male cases with complex karyotypes also lack the Y chromosome, a possible relation to HRS cells must be considered. The technique of simultaneous fluorescence immunophenotyping and interphase cytogenetic analysis (referred to as FICTION) is a powerful tool for studying the nature of cytogenetically abnormal cells. With the FICTION technique we studied four cases of HD in which the chromosome analysis had shown only the loss of the Y chromosome. Our aim was to clarify whether these karyotypes corresponded to the CD30-positive HRS cells. In two cases we found that HRS cells actually lacked the Y chromosome. There was strong evidence, however, that the HRS cells additionally had other chromosome aberrations and thus could not correspond to the cytogenetically determined karyotypes.

Cytogenetics↗

Comparison of cytogenetics and polymerase chain reaction based detection of the amelogenin gene polymorphism for the diagnosis of freemartinism in cattle.

A polymerase chain reaction (PCR) assay which detects a sex-based polymorphism in the bovine amelogenin locus was modified and compared to conventional cytogenetic analysis for diagnosis of freemartinism (XX/XY chimerism) in cattle. The PCR assay is more sensitive than cytogenetic analysis for detection of XY cells, with the limit of detection of the assay falling between 0.2% and 1% XY cells. Seventy-three heifer blood samples submitted for evaluation of freemartinism to the University of Minnesota Diagnostic Laboratory were tested using both cytogenetic and PCR techniques. Poor-quality samples precluded successful lymphocyte culture and recovery of mitotic nuclei for cytogenetic evaluation in 17 cases (23%). Two of these samples (2.7%) also failed to amplify with PCR. There was 100% agreement in the results from the 56 samples that were suitable for testing using both techniques. This PCR-based assay provides an alternative to the more laborious cytogenetic evaluation for diagnosis of freemartinism.

Amelogenin↗

Discrimination of distinct subpopulations within a tumor with combined double immunophenotyping and interphase cytogenetics.

We describe a method that enables detection and immunophenotypical characterization of distinct subpopulations within a cytogenetically defined tumor clone. Coexisting normal cells do not hinder microscopic evaluation because they can be distinguished from cytogenetically aberrant tumor cells. This is also true when normal and neoplastic cells cannot be clearly distinguished by cytology or immunohistochemistry, i.e., if both constituents have similar immunophenotypes and morphology. The method is based on fluorescence double staining for two different antigens combined with interphase cytogenetic analysis. It is referred to as "Fluorescence immunophenotyping and Interphase Cytogenetics as a Tool for Investigation of Neoplasms (FICTION)." In a case of follicular lymphoma we demonstrate that FICTION can differentiate bcl-2-positive malignant and non-malignant cells and can verify the presence of bcl-2-positive but cytogenetically inconspicuous T-lymphocytes.

Antigens, CD↗

Pretreatment cytogenetics add to other prognostic factors predicting complete remission and long-term outcome in patients 60 years of age or older with acute myeloid leukemia: results from Cancer and Leukemia Group B 8461.

We investigated the relative prognostic significance of cytogenetics in 635 adult acute myeloid leukemia (AML) patients 60 years of age or older treated on front-line protocols. Classification trees and tree-structured survival analysis (TSSA) were used to identify important cytogenetic groups, and their prognostic significance was then assessed in multivariable analysis (MVA). Overall, 48.5% achieved complete remission (CR); 6.6% survived at 5 years. Complex karyotypes with at least 3 abnormalities (complex > or = 3) and a group including "rare aberrations" predicted lower CR rates (25% and 30%) versus other patients (56%). Compared with complex > or = 3, the odds of CR were significantly higher for noncomplex karyotypes without rare aberrations on MVA. Cytogenetically, complex > or = 5 predicted inferior disease-free survival on TSSA, remaining significant on MVA together with white blood cell count (WBC), sex, and age. For survival, complex > or = 5, rare aberrations, and core-binding factor (CBF) abnormalities were prognostic (P < .001), with 5-year survivals of 0%, 0%, and 19.4%, respectively, and 7.5% for remaining patients. Together with WBC, marrow blasts, sex, and age, the cytogenetic groups remained significant on MVA. In conclusion, pretreatment cytogenetics adds to other prognostic factors in older AML patients. Patients with complex > or = 5 appear to benefit minimally from current treatment and are better suited for investigational therapy or supportive care.

Acute Disease↗