Biomedical subjects

D Catovsky

Publications and source records attributed to D Catovsky.

At least 163 records · Page 9Linked to original sources

PubMed1995

Molecular cytogenetics of chronic myeloid leukemia with atypical t(6;9) (p23;q34) translocation.

We report the molecular cytogenetic analysis of a case of Philadelphia (Ph)-negative, BCR-positive chronic myeloid leukemia (CML) which appeared by conventional cytogenetics to have a t(6;9)(p23;q34) as the sole cytogenetic abnormality. Neither conventional nor pulse-field Southern blots detected any rearrangement of the DEK or CAN genes which are often fused in acute myeloid leukemia (AML) with t(6;9)(p23;q34). However, rearrangements of both BCR and ABL genes were detected. The breakpoint in BCR was located in the major translocation cluster region between exons b1 and b3. ABL rearrangements were detected with an ABL exon 1B probe and with a probe located 5' of the entire ABL gene. Comigration between the rearranged fragments obtained with M-bcr-5' and ABL exon 1B probes was observed, implying that the entire ABL gene was fused to the 5' part of the BCR gene. Fluorescence in situ hybridization (FISH) analyses using BCR and ABL probes showed that in 20% of metaphases BCR and ABL signals were present on one chromosome 6 at 6p23, whilst in 80% of metaphases BCR and ABL signals were identified on both copies of chromosome 6. Furthermore, FISH analysis with a whole-chromosome 22 paint demonstrated that chromosome 22 material was present on both copies of chromosome 6. These data indicate a complex Philadelphia translocation involving chromosome band 6p23 and duplication of the whole aberrant chromosome. The nature of the gene locus on 6p23, involved in this rearrangement, remains unknown. A similar translocation has been previously reported in a case of CML, which also lacked DEK and CAN gene rearrangements implying that abnormalities of 6p23 involving genes other than DEK may be a recurrent abnormality in CML.

Blotting, Southern↗

PubMed1995

The sensitivity of leukemic bone marrow to simvastatin is lost at remission: a potential purging agent for autologous bone marrow transplantation.

BACKGROUND: Autologous bone marrow transplantation (ABMT) is frequently used in the treatment of malignant disease but carries the risk of reintroducing tumor cells into the patient. Methods are required for removing malignant cells from harvested bone marrow (BM) without impairing hematopoietic reconstitution. We have shown that simvastatin is toxic to leukemic progenitor cells at a concentration that conserves normal BM progenitors and may be of use clinically as a novel BM purging agent. METHODS: A two-stage culture system was used to compare the effects of simvastatin on both normal BM progenitor and primary acute myeloid leukemia (AML) cells. AML cells and normal BM mononuclear cells were incubated for 18 hours in suspension culture with 10 micrograms per mL simvastatin and the numbers of surviving clonogenic progenitor cells assayed in semisolid agar culture. RESULTS: Following simvastatin treatment of 18 AML cell populations, the mean surviving fraction of progenitor cells was 21.3 +/- 4.8% ( +/- standard error of the mean [SEM]). In contrast, the mean survival of normal BM progenitors from 16 donors was 89.6 +/- 8.6% ( +/- SEM). Samples were taken from 6 AML patients before treatment and after remission of disease had been induced by chemotherapy. In 5 of these cases the AML sample was significantly more sensitive to simvastatin than the remission sample, 4 of the 5 showed > 80% difference in progenitor cell survival. CONCLUSIONS: AML progenitor cells are sensitive to a short-term exposure to simvastatin that spares normal BM hematopoietic progenitor cells. We conclude that simvastatin may be an effective in vitro purging agent in ABMT for AML.

Acute Disease↗

PubMed1995

Chronic lymphoproliferative disorders.

There have been important advances in the diagnosis and treatment of chronic lymphoproliferative disorders. Three diseases stand out as examples of progress: chronic lymphocytic leukemia (CLL), hairy-cell leukemia (HCL), and adult T-cell leukemia-lymphoma. Improvements in diagnosis are the result of greater attention to cell morphology and the routine use of monoclonal antibodies, which in turn help define composite phenotypes that are specific for CLL and HCL. The combination of morphology and immunophenotype allowed the characterization of a new disorder, splenic lymphoma with villous lymphocytes, which was confused in the past with both CLL and HCL. The most important treatment developments stem from the availability of three nucleoside analogues: fludarabine, deoxycoformycin, and chlorodeoxyadenosine which, when used as single agents, are responsible for major improvements in remission rates in CLL (fludarabine, chlorodeoxyadenosine), HCL (deoxycoformycin, chlorodeoxyadenosine) and prolonged periods of disease-free survival. Adult T-cell leukemia-lymphoma remains a unique leukemia model, and interest in the worldwide distribution of the causative retrovirus, human T-cell lymphotropic virus I, continues with emphasis on epidemiologic and prevention studies.

Adult↗

PubMed1995

Differential TdT expression in acute leukemia by flow cytometry: a quantitative study.

Terminal deoxynucleotidyl transferase (TdT) has long been considered a diagnostic marker for acute lymphoblastic leukemia. Reports of TdT-positive cells in acute myeloid leukemia have lately questioned its diagnostic value. TDT has been detected mainly by microscopy methods: immunofluorescence and immunocytochemistry. The aim of this study was to reevaluate the diagnostic importance of TdT in acute leukemia by using flow cytometry with a method that allows quantitative analysis. Fifty-eight cases of acute leukemia were studied and TdT expression was quantified using calibrated fluorescent beads. The highest TdT values were found in B lineage acute lymphoblastic leukemia (ALL) while acute myeloid leukemia (AML) had the lowest values, even in cases with a high percentage of TdT-positive cells. Biphenotypic leukemia had intermediate values between B-lineage and T-lineage acute leukemia. The difference between these groups was statistically significant (P < 0.0001). The TdT assay by flow cytometry was more precise than immunocytochemistry because it recognizes quantitative differences between ALL and AML. It is also valuable in better defining the maturation stages in pre-B ALL and T-ALL. We conclude that quantitative flow cytometry of TdT re-establishes the diagnostic value of this enzyme and has potential applications for the study of minimal residual disease.

Acute Disease↗

PubMed1995

[Phenotypical diagnosis of Japanese chronic lymphocytic leukemia--an international cooperative study based on the French-American-British classification of mature B-cell leukemias].

To better understand the accuracy in the diagnosis of chronic lymphocytic leukemia (CLL) and characterize the clinical features of CLL in Japan, where the disease is extremely rare, an international cooperative study was conducted by hematologists between Japan and UK. Blood and bone marrow films from 36 patients with a possible-diagnosis of CLL were referred to two laboratories of Nagasaki University Hospital (Nagasaki) and Royal Marsden Hospital (London). According to the FAB criteria, typical CLL 16 and CLL/PL 2, a subtype of atypical CLL, were completely accordant in diagnosis. However, phenotypical diagnosis of CLL mixed, the other of atypical CLL, and intermediate lymphocytic leukemia (ILL) in leukemic phase often gave inconsistent results. Especially, 8 cases of atypical CLL designated as likely CLL were equivocal between CLL and ILL, suggesting clinical feature more close to typical CLL than ILL. This indicates the presence of a relatively high incidence of atypical CLL in Japan which dose not exactly fit with the FAB Criteria. Finally, we would like to emphasize that an international cooperative study allows improvement of accuracy in diagnosis and better understanding of the disease entity of lymphoid malignancies, having on ethnically different morbidity.

Aged↗

PubMed1994

The histopathology of splenic lymphoma with villous lymphocytes.

Whereas the hematologic, immunophenotypic, and molecular characteristics of splenic lymphoma with villous lymphocytes (SLVL) have been well documented, the histologic features of the spleen and lymph nodes remain uncharacterized. We have reviewed the histopathology of the spleen in 37 cases of SLVL and of involved splenic hilar lymph nodes in 6 cases. Tissue immunophenotyping was performed in 24 cases, 6 of which had frozen tissue available, and the results were compared with the membrane immunophenotype of the circulating villous lymphocytes and cells extracted from spleen and lymph nodes. In the spleen, SLVL is characterized by involvement of the white pulp follicles, which may be surrounded or replaced by the lymphoma cells. In the red pulp, the cells form small nodules and infiltrate diffusely with sinusoidal invasion. The cytologic appearance of the neoplastic cells varies from a resemblance to small mantle-zone--like lymphocytes to that of marginal-zone cells and there are scattered blast forms. In involved lymph nodes, the infiltrate again centers on the follicles that are usually replaced, but occasionally show preservation of follicle centers; sinuses are often preserved. The tissue immunophenotype is similar to that of marginal-zone B cells. Membrane immunophenotyping may give different results in some cases and may vary depending on the compartment from which the cells are obtained. SLVL in the peripheral blood is a histologically homogeneous entity identical to the condition previously characterised by histopathologists as splenic marginal-zone lymphoma.

Adult↗

PubMed1994

Adult T-cell leukemia/lymphoma: a working point-score classification for epidemiological studies.

Adult T-cell leukemia/lymphoma (ATL) is a malignancy that occurs most frequently in south-western Japan and the Caribbean basin. The primary etiologic agent for this disease, human T-lymphotropic virus type I (HTLV-I), is endemic in these areas. Only a small percentage of individuals infected with HTLV-I develop ATL. The factors that determine the development of malignant disease as an outcome of HTLV-I infection in an individual are unknown. ATL is histopathologically heterogeneous and firm diagnosis is made on the contribution of clinical, laboratory and histopathologic features. The wide variety of laboratory assays available to geographically diverse populations has led to a need to standardize the criteria for determining the diagnosis of this disease for epidemiologic studies. This report summarizes current information regarding ATL and proposes a classification facilitating comparison of case series in geographically and ethnically different populations.

Adult↗

PubMed1994

Splenic lymphoma with villous lymphocytes: analysis of BCL-1 rearrangements and expression of the cyclin D1 gene.

The translocation t(11;14)(q13;q32) occurs in about 15% of patients with splenic lymphoma with villous lymphocytes (SLVL) or the closely related disorder lymphoplasmacytic lymphoma (LPL). To characterize the nature and frequency of rearrangements of the BCL-1 locus in SLVL/LPL and to document the effect of these genetic alterations on the expression of the cyclin D1 gene, we analyzed 22 cases of SLVL/LPL with defined cytogenetic abnormalities by both conventional electrophoresis (CE) and pulse-field gel electrophoresis (PFGE) and by Northern blotting. Four SLVL/LPL cases showed rearrangement of the BCL-1 locus. In two cases with t(11;14)(q13;q32), different breakpoints were identified; one mapped adjacent to the major translocation cluster (MTC) and the other within a 28-kb region telomeric of it. In a third case of SLVL with no cytogenetic abnormality of 11q13, a novel breakpoint approximately 100 kb centromeric of MTC was detected by PFGE. The fourth case, which had a normal karyotype, demonstrated rearrangement with a BCL-1 probe immediately telomeric of MTC. This case may have had a small deletion of 0.5 kb from within the BCL-1 locus. No rearrangement of the BCL-1 locus or within the cyclin D1 gene was detected by CE or PFGE in any of the remaining 18 SLVL/LPL samples. Northern blot analysis showed expression of a normal-sized cyclin D1 transcript in the two SLVL/LPL cases with t(11;14)(q13;q32). In cases that lacked a cytogenetically demonstrable t(11;14) translocation, no cyclin D1 transcript was detected. Analysis of the BCL-1 locus was also performed in three other cases of B-cell disorders with t(11;14)(q13;q32) detected cytogenetically. Two cases were analyzed by Southern blot and showed rearrangement of the BCL-1 locus. Expression of high-level normal-sized and/or truncated cyclin D1 transcript was also detected in these cases. These data show the importance of PFGE in the detection of rearrangements in the BCL-1 locus and show further the complexity of rearrangements in this locus.

Chromosomes, Human, Pair 11↗

PubMed1994

Interstitial insertion of retinoic acid receptor-alpha gene in acute promyelocytic leukemia with normal chromosomes 15 and 17.

The translocation t(15;17)(q22;q21) is seen exclusively in patients with acute promyelocytic leukemia (APL) and in the promyelocytic blast crisis of chronic myeloid leukemia (CML). This translocation juxta-poses the promyelocytic leukemia (PML) gene on chromosome 15 and the retinoic acid receptor-alpha (RARA) gene on chromosome 17, resulting in the formation of a chimeric mRNA transcript. We describe a patient with the microgranular variant form of APL, with no detectable cytogenetic abnormality of either chromosomes 15 or 17, who nevertheless had juxtaposition of PML and RARA genes and expressed a chimeric transcript. Conventional cytogenetics showed the karyotype 46,XY,d-er(3)t(3;8)(p25;q12). Fluorescent in situ hybridization (FISH) with paints for chromosomes 8, 15, and 17 confirmed the presence of structurally intact chromosomes 15 and 17 and trisomy for chromosome 8q. Nevertheless, FISH using cosmid probes for PML and RARA showed their juxtaposition on one chromosome 15 homolog. Both genes were also present on their normal homologs; in addition, part of the RARA gene was still present on the remaining chromosome 17. DNA analysis by Southern blotting, performed with a variety of probes including PML, RARA and retinoic acid receptor-beta (RARB), showed a rearrangement in PML. Reverse transcriptase polymerase chain reaction (RT-PCR) confirmed the existence of hybrid transcripts of 276, 455 bp and 623 bp, from PML-RARA on the der(15) chromosome, consistent with alternate exon splicing of the long form of the transcript occurring in 50% to 60% of patients with APL. Our results show that APL patients with cytogenetically normal chromosomes 15 and 17 may, nevertheless, have involvement of both PML and RARA genes defining a subgroup of APL, t(15;17)-negative/PML-RARA-positive which is analogous to Philadelphia chromosome-negative/BCR-ABL-positive CML. In this case, the presence of chimeric transcripts suggests that treatment with all-trans RA may be warranted in APL, even in the absence of detectable cytogenetic change, showing the usefulness of RT-PCR or FISH to aid diagnosis.

Base Sequence↗

PubMed1994

The immunophenotype of splenic lymphoma with villous lymphocytes and its relevance to the differential diagnosis with other B-cell disorders.

Splenic lymphoma with villous lymphocytes (SLVL) is a low-grade disorder that regularly presents with peripheral blood involvement. We describe the immunophenotype of the circulating cells from 100 SLVL patients whose disease has been characterized on clinical, morphologic, and histologic grounds. Cells from all cases expressed B-cell antigens (CD19 and CD37) and/or HLA-Dr and showed light chain restriction (kappa/lambda: 1.5/1) with moderate to strong intensity of membrane Ig staining. Cells from most cases (> 80%) were CD24+, FMC7+, and expressed strongly membrane CD22. The monoclonal antibodies CD10, CD23, and CD38 were positive in one-third of the cases; CD11c in 47%; and CD25 in 25% of cases. A minority of cases (< 20%) were positive with HC2, B-ly-7, and CD5. However, none of the 19 CD5+ cases had the phenotype characteristic of chronic lymphocytic leukemia (CD5+, CD23+, FMC7-, weak surface Ig and membrane CD22). None of the 17 CD25+ cases had the immunophenotype typical of hairy cell leukemia (CD25+, CD11c+, HC2+, B-ly-7+). HC2 and B-ly-7 were the most useful reagents to distinguish SLVL from hairy cell leukemia. Our findings demonstrate that SLVL has a distinct immunologic profile and that monoclonal antibodies are important for the differential diagnosis between this disease and other B-lymphoproliferative disorders with which SLVL can be confused.

Adult↗

PubMed1994

Chromosome abnormalities in hairy cell leukaemia variant.

We describe chromosome abnormalities in 6 patients with hairy cell leukaemia (HCL) variant, a rare B-cell disorder with clinical and laboratory features intermediate between HCL and B-prolymphocytic leukaemia (B-PLL). All but one had marked splenomegaly and a raised white blood cell count (median 40 x 10(9)/l) with over 80% nucleolated hairy cells. These cells had a B-cell immunophenotype distinct from that of typical HCL. All patients but one are alive with stable disease with a median follow-up of 60 months. Numerical chromosome changes included loss of chromosomes 2, 3, 4, 6, 10, 19, 21, and X. three cases had translocations involving the immunoglobulin gene regions: t(14;17)(q32;q11), t(14;22)(q32;q11), and t(2;8)(p11.12;q24). Immunocytochemistry demonstrated the presence of the MYC protein in cells from the case with t(2;8) but not in two others. Other structural abnormalities included t(3;10)(q27;q22) and t(3;12)(q27;q13) in the same patient, der(17)t(7;10;17)(p11;q27;q22), t(1;3)(q25;p21), t(8;21)(p12;q11), t(17;21)(p11;p11), del(6)(q15), del(7)(q34), and del(14)(q24).

Aged↗

PubMed1994

Acute myelomonocytic leukemia with t(10;11)(p13;q23): heterogeneity of breakpoints at 11q23 and association with recombinase activation.

The human trithorax homolog gene (MLL) is directly involved in over 90% of cases of acute leukemia with abnormalities of 11q23. However, involvement of other genes at 11q23 both centromeric and telomeric of MLL has been identified in different subtypes of leukemia and lymphoma. We describe a case of acute myelomonocytic leukemia (AMML; FAB type M4) with t(10;11)(p13;q23) in which the breakpoint at 11q23 was centromeric to the MLL gene and distinct from the breakpoint seen in promyelocytic leukemias with t(11;17)(q23;q22), thus providing further evidence of heterogeneity of breakpoints in 11q23 in acute leukemia. Rearrangements of immunoglobulin (IG) and T-cell receptor (TCR) genes were also observed, with no immunophenotypic evidence for commitment to the lymphoid lineages, indicating that inappropriate activation of the recombinases may be a feature of this particular variant translocation.

Adult↗

PubMed1994

Persistent polyclonal B-cell lymphocytosis.

We document a case of persistent lymphocytosis in which the characteristic binucleated circulating lymphocytes were shown immunologically to be polyclonal B-cells. Cytogenetic and molecular studies failed to show a clonal population. A review of the literature on this rare condition, persistent polyclonal B-cell lymphocytosis, highlights an association with the female sex, HLA-DR7 antigen, smoking and raised levels of IgM, all of which were present in our patient.

B-Lymphocytes↗

PubMed1994

Trisomy 12 in B-cell chronic lymphocytic leukaemia: assessment of lineage restriction by simultaneous analysis of immunophenotype and genotype in interphase cells by fluorescence in situ hybridization.

We have studied the lineage restriction of trisomy 12 in six patients with B-cell chronic lymphocytic leukaemia (CLL) by simultaneous analysis of immunophenotype and fluorescence in situ hybridization (FISH) signals in single interphase cells. Fresh uncultured cells from each patient were immunophenotyped by the alkaline phosphatase anti-alkaline phosphatase method (APAAP) using monoclonal or polyclonal antibodies and hybridized with a chromosome 12 specific alpha-satellite DNA probe. In all cases trisomy 12 was restricted to the clonal B-cells, kappa positive or lambda positive, whereas T-cells (CD3 positive) and non clonal B-cells had only two chromosome 12 signals. Within the clonal B-cell population a large proportion of cells were disomic for chromosome 12, whilst trisomic cells ranged from 21% to 37%. The absence of trisomy 12 in T-cells and the mosaicism demonstrated in the clonal B-cells suggests that this abnormality is a secondary event during the leukaemic transformation of CLL and develops in an already established neoplastic B-cell population.

Aged↗

PubMed1994

First report of fludarabine in gamma-heavy chain disease.

We describe a case of gamma-heavy chain disease presenting with lymphadenopathy, splenomegaly, lytic lesions and bone marrow infiltration. Chemotherapy with epirubicin, chlorambucil and prednisolone produced a partial remission which lasted 5 months. The patient was then treated with fludarabine. After six courses of fludarabine a good partial remission was achieved which converted to complete remission with disappearance of the monoclonal IgG3 in the ensuing 12 months without further therapy. This response has, so far, been sustained for 2 1/2 years after stopping treatment.

Aged↗

PubMed1994

The chronic myeloid leukaemias: guidelines for distinguishing chronic granulocytic, atypical chronic myeloid, and chronic myelomonocytic leukaemia. Proposals by the French-American-British Cooperative Leukaemia Group.

We have reviewed our experience with four of the entities that are included under the generic term chronic myeloid leukaemia (CML), namely the classic Ph+ CGL, both BCR+ and BCR-, aCML and CMML. We have developed a statistical model that confirms that CGL, aCML and CMML can be distinguished from each other with reasonable success employing five quantitative parameters (WBC, percentage immature granulocytes, percentage monocytes, percentage basophils, percentage erythroid precursors in bone marrow) and one qualitative parameter (granulocytic dysplasia). It is hoped that these detailed recommendations will enable investigators to improve their diagnostic accuracy. This should permit more uniform comparisons of molecular biologic and clinical studies.

Bone Marrow↗

PubMed1994

Demonstration of cytoplasmic and nuclear antigens in acute leukaemia using flow cytometry.

AIMS: To detect cytoplasmic and nuclear antigens using flow cytometry in acute leukaemia and to use this technique for double marker combinations. METHODS: Cytoplasmic staining was carried out in samples from 40 cases of acute leukaemia with monoclonal antibodies against the myeloid antigen CD13, the lymphoid antigens CD3, CD22, mu chain and the enzymes terminal deoxynucleotidyl transferase (TdT) and myeloperoxidase (MPO). The cells were fixed with paraformaldehyde and permeabilised with Tween 20 and Becton Dickinson's FACS lysing solution. Flow cytometry results were compared in the same cases with immunocytochemistry results using the alkaline phosphatase anti-alkaline phosphatase method. RESULTS: The gentle permeabilisation induced by this method permitted preservation of the membrane antigens and the size and morphology of the cells. The results using flow cytometry were comparable with those obtained using immunocytochemistry, with nearly complete concordance in most cases. CONCLUSIONS: This technique is simple, rapid, sensitive and reproducible and it is suitable for double staining procedures, such as nuclear and cytoplasmic, nuclear and membrane, or cytoplasmic and membrane. It therefore provides a powerful tool for extending the use of immunophenotyping for the diagnosis and follow up of acute leukaemia. It could also be used for the investigation of minimal residual disease.

Acute Disease↗

PubMed1994

The role of pentostatin in the treatment of T-cell malignancies: analysis of response rate in 145 patients according to disease subtype.

PURPOSE: To assess the results of treatment with the purine analog 2'deoxycoformycin (pentostatin [DCF]) in patients with postthymic T-cell malignancies. PATIENTS AND METHODS: One hundred forty-five patients with postthymic T-cell malignancies were given DCF intravenously at 4 mg/m2/wk for the first 4 weeks and then every 2 weeks until maximal response; the last 30 patients received weekly injections until maximal response. RESULTS: The overall response rate was 32% (complete responses [CRs] plus partial responses [PRs]), with marked variation according to diagnosis. The best responses occurred in patients with Sézary syndrome (62%) and T-prolymphocytic leukemia (T-PLL) (45%), with CRs in three of 16 Sézary syndrome and five of 55 T-PLL patients. In contrast, no responses (NRs) were documented in 13 patients with other types of cutaneous T-cell lymphoma, including five mycosis fungoides. Two of five patients with large granular lymphocyte (LGL) leukemia had a CR and two of four with Sézary cell leukaemia had a PR. A low response rate was observed in 27 patients with peripheral T-non-Hodgkin's lymphoma (T-NHL) (19%) and in 25 with adult T-cell leukemia/lymphoma (ATLL) (12%). The latter included two CRs and one PR. Toxicity was low and DCF was generally well tolerated. No significant differences were observed when results were analyzed according to previous treatment. Disease subtype was the most important factor to influence results. CONCLUSION: We conclude that DCF is effective as a single agent in T-PLL, Sézary syndrome, and LGL leukemia, but has low activity in other T-cell disorders.

Adult↗