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D Catovsky

Publications and source records attributed to D Catovsky.

At least 253 records · Page 14Linked to original sources

A classification of acute leukaemia for the 1990s.

The need for reproducibility in the classification of acute leukaemia has made it necessary to incorporate information derived from new techniques which have become essential for the study of these disorders. In addition to classic morphology and cytochemistry (FAB proposals), it is necessary to add immunology and cytogenetics (MIC proposals), as well as to investigate further the biological and diagnostic significance of molecular events. As a result of these investigations a new group of leukaemias merit recognition as distinct entities. These include three types of ALL with specific chromosome abnormalities, namely, i) t (9;22), ii) t (4;11) and iii) t (1;19) and four subtypes of AML, i) with minimal differentiation or AML-M0, ii) with basophilic precursors or M2Baso, iii) AML (M4/M5) with t (8;16) and iv) AML with trilineage myelodysplasia. Biphenotypic acute leukaemia constitutes also a distinct entity with features of ALL and AML and represents a malignancy probably affecting multipotent stem cells. We propose an objective evaluation system for biphenotypic leukaemias based on a score in which the various lineage markers are graded according to their known specificity.

Humans↗

HTLV-1 envelope sequences from Brazil, the Caribbean, and Romania: clustering of sequences according to geographic origin and variability in an antibody epitope.

We sequenced the envelope genes of Human T-cell leukemia type I viruses (HTLV-I) derived from five Brazilian, two Caribbean, and one Romanian case of adult T-cell leukemia after amplification of the complete env gene by PCR. A comparison with previously reported HTLV-I sequences revealed that, although highly homologous, no two env sequences were identical. All envelope sequences differed from each other by 0.3-2.1% nucleotide differences. The five Brazilian sequences clustered together and were about as different from each other (0.5-0.75% nucleotide difference) as were three previously reported Japanese sequences (0.7-0.95%). In contrast, sequences of Caribbean origin were less homogeneous (0.5-1.9% nucleotide differences within this group). The Romanian sequence was not significantly more divergent than any of the others and was closest to our two Caribbean sequences. We observed two changes in a region (aa 176-209) which has previously been shown to contain a linear antibody epitope recognized by most human sera from seropositive individuals. One of these changes affects the binding of monoclonal antibodies to this epitope demonstrating the variability of an antibody epitope in the HTLV-I envelope.

Amino Acid Sequence↗

Inversions and tandem translocations involving chromosome 14q11 and 14q32 in T-prolymphocytic leukemia and T-cell leukemias in patients with ataxia telangiectasia.

Ataxia telangiectasia (AT) and T-prolymphocytic leukemia (T-PLL) have similar chromosome abnormalities. Cytogenetic findings reported in 5 patients with AT who developed T-cell leukemia revealed: inv(14)(q11q32) (1 case), tandem translocations of chromosome 14 with breakpoints at q11 and q32 (3 cases), and int. del(14)(q11q32) (1 case). Additional abnormalities were present in 4 patients of whom two had trisomy for 8q. Of 27 patients with T-PLL but without AT, investigated by us, 17 had inv(14)(q11q32) and 3 had tandem rearrangement of chromosome 14 with breaks at 14q11 and q32; 15 of them also had rearrangements resulting in trisomy 8q. Two of the leukemias supervening on AT had morphology and clinical course suggestive of T-PLL. Two other cases of AT studied by us developed typical T-PLL at a young age (18 and 39 years). T-cell clones carrying an inv(14), tandem t(14;14) and t(X;14) can be present in AT for long periods of time without evolving into leukemia. In T-PLL, inv(14) and t(14;14) always occurs with other chromosome abnormalities. We suggest that these additional chromosome abnormalities may be required for the leukemic transformation of AT. This is supported by one of the two AT cases studied by us in which a long-standing t(X;14) clone evolved with the formation of t(1;14)(p21;q11), t(8;22)(q24;q11) at the time of the development of T-PLL.

Ataxia Telangiectasia↗

Fludarabine phosphate for the treatment of low grade lymphoid malignancy.

Thirty-four patients with previously treated, advanced, low grade NHL were treated with Fludarabine, a deamination-resistant analogue of adenosine arabinoside, at a dose of 25 mg m-2 intravenously, daily for 5 days (median number of cycles = 3, range 1-10). Complete remission (CR) was achieved in six and partial remission (PR) in a further seven. Overall, responses were seen in 11/23 patients (48%) with follicular lymphoma and in 2/11 (18%) with low grade, diffuse NHL. Fifteen patients with previously treated CLL and one patient with prolymphocytic leukaemia (PLL) were also treated as above (median no. of cycles = 3, range 1-6). A partial response was seen in three of the 11 evaluable patients with CLL and CR was achieved in the patient with PLL. There were four deaths due to infection and 19 further episodes requiring admission to hospital. No other significant toxicity was reported in a total of 164 cycles of Fludarabine. This agent is active in advanced low grade lymphoid malignancy. Further studies are required to assess its role in newly diagnosed patients.

Antineoplastic Agents↗

Deoxycoformycin in the treatment of mature T-cell leukaemias.

We describe the results of treatment with 2'-deoxycoformycin (DCF) in 68 patients with post-thymic (mature) T-cell malignancies. These included: prolymphocytic leukaemia (T-PLL), 31, HTLV-1 + adult T-cell leukaemia/lymphoma (ATLL), 20, cutaneous T-cell lymphoma (CTCL), comprising mycosis fungoides and Sezary syndrome, 13, and large granular lymphocytic leukaemia, four. Two-thirds of patients were refractory to previous therapy, which included four drug combinations. DCF was given intravenously at 4 mg m-2 weekly for the first 4 weeks and then every 2 weeks until maximal response. Toxicity was very low with only one death resulting from prolonged neutropenia. Overall response rates, partial (PR) and complete. (CR), were 38%, with variations according to diagnosis. Best responses, 54%, were seen in CTCL but limited to Sezary patients, one CR, six PR, whilst none of the mycosis fungoides responded. Responses in T-PLL were recorded in 48% including three CR (of 8-12 months' duration unmaintained) and 12 PR. Fifteen per cent of responses were seen in ATLL. The only ATLL responders - two CR, one PR - were those patients who received combination chemotherapy prior to DCF, with reduction of tumour bulk but short of PR. When results were analysed according to membrane phenotypes it was apparent that responses were seen mainly in cases with CD4+, CD8- T cells -22 of 47 (47%) - contrasting with only three of 19 (16%) with other T-cell phenotypes. We conclude that DCF is a useful therapy for the treatment of T-cell leukaemias, in particular Sezary syndrome and T-PLL, and should play a part in strategies to improve the natural history of this group of lymphoid malignancies.

Adult↗

Splenic lymphoma with villous lymphocytes: natural history and response to therapy in 50 cases.

We studied the natural history and response to treatment in 50 patients with splenic lymphoma with villous lymphocytes followed for a minimum of 6 months and up to 15 years (median 3.7 years). The disease occurs in the elderly (median 68 years) and affects males more than females (M/F ratio 1.77). The median survival for the group was not reached but 82% were surviving at 3 years and 78% at 5 years. Twelve patients (24%) died, one-third of deaths were disease related (four patients) and one-half were due to cardiovascular disease or another malignancy (six patients). The outcome was worse for males (31% died) than females (11% died). Fourteen patients were not treated and 10 remain alive between 1 and 6 years from diagnosis. The remaining patients were treated by chemotherapy, splenic irradiation or splenectomy. The response to chemotherapy was poor and only eight of 22 (36%) patients treated achieved a good response. Splenic irradiation was employed in seven patients and three benefited from it. Splenectomy seems to be the treatment of choice, with significant improvement seen in 19 of 20 patients with one post-operative death. This response, lasting from 6 months to 7 years (median 4 years), was seen irrespective of whether splenectomy was the initial treatment or used later in management.

Adult↗

Proposal for the recognition of minimally differentiated acute myeloid leukaemia (AML-MO)

We describe a form of acute myeloid leukaemia (AML), designated AML-MO, with minimal myeloid differentiation, not included previously in the FAB classification. AML-MO cannot be diagnosed on morphological grounds alone as the blast cells are large and agranular, sometimes resembling L2 or, rarely, L1 lymphoblasts, and should be identified by the following features: negative myeloperoxidase (MPO) and Sudan Black B reaction (or positive in less than 3% of blasts), negative B and T lineage markers and expression of myeloid antigens recognized by at least one monoclonal antibody, CD13 or CD33. Other myeloid markers are also often positive and these include CD11b and the enzyme MPO demonstrated by immunocytochemistry and/or electron microscopy analysis. The findings in a group of 10 cases satisfying the criteria for AML-MO are described. AML-MO represents 2-3% of all cases of AML and 1-1.5% of all acute leukaemias. Its clinical and biological significance is not yet apparent but its identification in a larger number of cases may achieve this aim.

Acute Disease↗

Leukaemia as a manifestation of large cell lymphoma.

A leukaemic phase is uncommon in large cell lymphoma, particularly at presentation of the disease, and very few cases have been reported since immunological markers became available. We have studied 24 cases presenting over a period of 15 years. 16 were B-lineage and eight T-lineage. In five patients the large cell lymphoma represented a transformation of a preceding low grade, small cell lymphoproliferative disease. Three other patients with T-lineage large cell lymphoma presented with skin infiltration (two cases) or lymphoma-associated nephrotic syndrome (one case) 3-9 months before leukaemia occurred. The other 16 patients (12 B-lineage and four T-lineage) presented with de novo large cell leukaemia/lymphoma. With the exception of skin infiltration, clinical features did not differ between T and B-lineage cases. Prognosis was generally poor although a minority of patients lived 1-2 years. Median survival was 7 months. In the B-cell lymphomas immunological markers were those expected but among the T-cell cases there were many unusual immunophenotypes with frequent failure to express markers which are usually positive in peripheral T cells. Without the availability of immunological markers diagnosis would have been difficult, with acute myeloid leukaemia being the most important differential diagnosis. T-lineage and B-lineage cases could not be distinguished on cytological features. In the majority of cases the cells were very pleomorphic with nuclear lobulation, prominent nucleoli and marked cytoplasmic basophilia being commonly observed. Marked nuclear lobulation was not confined to T-lineage cases but was seen also in seven of 12 cases of de novo B-lineage leukaemia/lymphoma; it was readily apparent in histological sections and on ultrastructural examination.

Adolescent↗

Translocations t(14;18) and t(8;14) with rearranged bcl-2 and c-myc in a case presenting as B-ALL (L3).

Follicular lymphoma is a low grade malignancy characterized by the translocation t(14;18), which involves the putative oncogene bcl-2. We describe a 73-year-old patient presenting with Burkitt acute lymphoblastic leukemia (B-ALL) L3 (Burkitt type), whose cells had the following immunophenotype: CD19+, CD22+, HLA-DR+, CD10+, TdT-, Cyt IgM-, CD34-. Analysis of 25 peripheral blood metaphases showed the presence of t(14;18) (q32;q21), and t(8;14) (q24;q32) in 24 cells and t(14;18) only in one cell, suggesting that the latter translocation came first during clonal evolution. Both bcl-2 and c-myc were rearranged in addition to the immunoglobulin heavy and light chain genes. The presence of small lymphoid cells in paratrabecular areas on the bone marrow biopsy, together with evidence of cytogenetic clonal evolution, was indicative of a transformation from a low grade follicular lymphoma to a more aggressive Burkitt type malignancy.

Aged↗

Adult T-cell leukaemia/lymphoma in Brazil and its relation to HTLV-I.

In a series of fourteen patients with adult T-cell lymphoma-leukaemia (ATLL) in Brazil the main features were lymphadenopathy, hepatosplenomegaly, hypercalcaemia, and high leucocyte counts, with abnormal lymphoid cells which had irregular nuclei. The series included the youngest patient with ATLL so far (18 months). Analysis with monoclonal antibodies showed a mature T-cell phenotype (CD4+, CD8-). Antibodies to HTLV-I and/or integration of HTLV-I proviral DNA were found in eleven patients. In the other three HTLV-I DNA could not be demonstrated even by means of the polymerase chain reaction; they therefore had HTLV-I-negative ATLL. This report of ATLL in Brazil corroborates serological reports that HTLV-I may be endemic in some parts of that country. Follow-up studies are required to identify precisely the main route of transmission of HTLV-I in South America and the risk factors for the development of ATLL in carriers.

Adult↗

B-ly-7, a monoclonal antibody reactive with hairy cell leukemia, also defines an activation antigen on normal CD8+ T cells.

We undertook a study to determine the specificity of the monoclonal antibody, B-ly-7, for hairy cell leukemia (HCL) by examining the expression in 150 samples from B-cell lymphoproliferative diseases as well as screening for reactivity in a number of other hematologic malignancies. Within the B-cell lineage we found that the expression of B-ly-7 was highly specific for HCL and reacted with all 28 cases examined, as well as with 3 of 9 cases of a variant form of HCL. Cells of other closely related B-cell disorders, prolymphocytic leukemia, and splenic lymphoma with villous lymphocytes were negative. Investigation of the peripheral blood and bone marrow of patients with HCL before and after treatment with alpha-interferon or deoxycoformycin suggests that B-ly-7 may be useful in the assessment of minimal disease after therapy. In addition to HCL, we found that B-ly-7 was positive with cells of three mature, CD4+ T-cell malignancies. In view of the reactivity with malignancies of activated B and T cells, we searched for the expression of B-ly-7 on activated, normal B and T cells and found that B-ly-7 reacted specifically with activated normal peripheral blood CD8+ T cells. B-ly-7 has a number of applications, including the precise classification of mature B-cell neoplasia and the diagnosis HCL and its assessment after treatment. In addition, B-ly-7 recognizes a small subset of T-cell disorders. Its expression on these malignancies and on in vitro activated peripheral blood CD8+ T cells suggests that B-ly-7 detects a lymphocyte activation antigen.

Antibodies, Monoclonal↗

A variant form of hairy cell leukemia resistant to alpha-interferon: clinical and phenotypic characteristics of 17 patients.

We describe the clinical and laboratory features of 17 adult patients with a variant form of hairy cell leukemia (HCL-V) studied over the last 7 years. The main findings were: splenomegaly, moderate anemia, thrombocytopenia, and a raised white blood cell count (median 116 x 10(9)/L; range 15 to 482). The circulating lymphoid cells had abundant villous cytoplasm and a round, occasionally bilobed nucleus, with a prominent nucleolus. Monocytopenia, a feature of typical HCL, was not seen; neither was tartrate-resistant acid phosphatase demonstrated in eight cases tested. HCL-V cells had a mature B-cell phenotype: CD19+, CD20+, CD22+, FMC7+, CD11c+, CD10-, CD5-, with light chain isotope restriction in 15 cases. In contrast to typical hairy cells, HCL-V cells were negative with the monoclonal antibodies anti-HC2 and anti-TAC (CD25). Immunoglobulin (Ig) was not detected in two cases and IgG was expressed in the cell membrane of 73% of cases. Bone marrow histology was different from HCL, showing interstitial infiltration by cells clumped together and a moderate amount of reticulin, but the spleen showed the typical red pulp expansion of HCL. HCL-V patients did not respond to splenectomy (5 of 7) or alpha-interferon (7 of 7); 2 of 3 patients had a partial response to 2'deoxycoformycin. The clinical course was benign with 15 patients alive with a median survival greater than 4 years. We confirm that HCL-V is a distinct clinico-pathologic entity with intermediate features between HCL and B-prolymphocytic leukemia.

Aged↗

Oestrogen receptor (ER) analysis in B-cell chronic lymphocytic leukemia: correlation of biochemical and immunocytochemical methods.

Oestrogen receptors (ER) are present in neoplastic lymphoid cells and have been considered a physiological marker of growth rate or differentiation. Tamoxifen, an oestrogen antagonist, has been given in some patients with CLL and Hodgkin's disease, with dramatic response in single cases. Until now, ER status has been assessed using a steroid binding assay (SBA) which has many inherent problems. Recently, the development of monoclonal antibodies directed against ER has been applied to the study of breast carcinomas and results obtained show good correlation with the quantitative SBA. We studied 49 cases of B-cell chronic lymphocytic leukemia (CLL) using immunostaining of cytospin preparations. In 30 of these cases ER enzyme immunoassay (ER-EIA) was also performed. Cultured MCF-7 cells, derived from a pleural effusion of a breast cancer patient, known to contain high levels of ER were used as a positive control (40-48% ER positive cells by immunocytochemistry; 200 fmol/mg protein by EIA). All of the CLL cases except two (96%) were negative for ER (less than 1% staining; less than 4 fmol/mg protein). The two positive cases expressed granular ER staining over the nucleus (9.2 and 12.1% positive cells) and were positive by EIA and SBA. It is concluded that (i) patients with CLL rarely express ER and (ii) immunocytochemical staining of cytospin preparations is a valid technique for the measurement of ER. It is of interest that one of the positive cases was diagnosed as CLL with Richter's transformation confirming earlier findings.

Adult↗

The distribution of CD45R, CD29 and CD45RO (UCHL1) antigens in mature CD4 positive T-cell leukaemias.

We have studied the expression of antigens characterizing functional T-cell subsets in 32 CD4+ mature T-cell leukaemias. In this analysis we used two monoclonal antibodies (McAb) of the CD45R group (2H4 and GRT22) which have been shown to identify the 'native/virgin' T-cell population that functions as 'suppressor-inducer' cells in vitro, and two McAb, CD29 (4B4) and CD45RO (UCHL1), which characterize non-identical 'memory' cells that proliferate in response to soluble recall antigens and provide help in antigen-specific IgG synthesis. Four groups of CD4+ cases were identified according to this reactivity: (a) 15 CD45R+, CD29+; (b) 13 CD45R-, CD29+; (c) three CD45R-, CD29-; and (d) one case only CD45+, CD29-. The high incidence of coexpression of CD45R and CD29 (47% of cases) is a new finding which contrasts with the mutual exclusion of these antigens on normal CD4+ T-lymphocytes. There was no correlation between subset phenotypes and pathological disease entities. None of the six cases of adult T-cell leukaemia/lymphoma (ATLL), which is known as a disorder of activated 'suppressor-inducer' cells, had the 'expected' CD45R+, CD29- phenotype. Reactivity with UCHL1 showed a good correlation with CD29 in the CD45R- CD29+ cases which included three with ATLL. These results may help in the further characterization of T-cell malignancies according to functional subgroups and may clarify further the role of T-differentiation antigens in health and disease.

Antigens, CD↗