Changes in membrane markers and chromosome patterns in chronic T-cell leukemia

CuZnSOD deficiency leads to persistent and widespread oxidative damage and hepatocarcinogenesis later in life

Mice deficient in CuZn superoxide dismutase (CuZnSOD) showed no overt abnormalities during development and early adulthood, but had a reduced lifespan and increased incidence of neoplastic changes in the liver. Greater than 70% of Sod1-/- mice developed liver nodules that were either nodular hyperplasia or hepatocellular carcinoma (HCC). Cross-sectional studies with livers collected from Sod1-/- and age-matched +/+ controls revealed extensive oxidative damage in the cytoplasm and, to a lesser extent, in the nucleus and mitochondria from as early as 3 months of age. A marked reduction in cytosolic aconitase, increased levels of 8-oxo dG and F2-isoprostanes, and a moderate reduction in glutathione peroxidase activities and porin levels were observed in all age groups of Sod1-/- mice examined. There were also age-related reductions in Mn superoxide dismutase activities and carbonic anhydrase III. Parallel to the biochemical changes, there were progressive increases in the DNA repair enzyme APEX1, the cell cycle control proteins cyclin D1 and D3, and the hepatocyte growth factor receptor Met. Increased cell proliferation in the presence of persistent oxidative damage to macromolecules likely contributes to hepatocarcinogenesis later in life.

Clonal evolution of T-cell chronic lymphocytic leukaemia in a patient with ataxia telangiectasia

Ataxia telangiectasia (A-T) is an autosomal recessive disorder in which patients show an unusual predisposition to malignant disease, including T-cell chronic lymphocytic leukaemia. We report here the steady growth over 5 years of a complex, cytogenetically abnormal clone of T lymphocytes in an A-T patient who was subsequently found to have an OKT3/OKT8 chronic lymphocytic leukaemia. The tumour cells at diagnosis had clearly evolved from a pre-existing, cytogenetically abnormal T-cell clone which contained an inv(14) chromosomal inversion alone.

Chromosome studies in patients with T-CLL chronic lymphocytic leukemia and expansions of granular lymphocytes

Chromosome analyses were carried out in eight patients with lymphoproliferative disorders of mature T and NK cells. Three cases were characterized by an abnormal expansion of granular lymphocytes (GL), one by a lymphoma of GL with leukemic spread, and four by an OKT4-T-CLL. In four patients cytogenetic studies were performed on bone marrow cells; in seven patients peripheral blood lymphocytes were examined by either direct preparations or PHA-stimulated cultures. Six patients displayed a normal karyotype. Two cases belonging to the OKT4-T-CLL group had a chromosome number ranging from 44 to 47, with multiple numerical and structural clonal anomalies. Clonal anomalies could be a feature of patients with the more aggressive clinical course.

Chromosomal aberrations in a case of T-cell CLL with concomitant IgA myeloma

Four consistent markers, involving chromosomes 8, 11, 14, 18, 21 and 22, were found in the majority of metaphases obtained after stimulation of peripheral blood and bone marrow from a patient with a T-cell chronic lymphocytic leukemia (CLL) and a concomitant IgA/lambda myeloma with phytohemagglutinin (PHA), lipopolysaccharide of E. coli (LPS) and S. aureus strain Cowan I bacteria (Cowan). A second malignant clone with three additional markers was observed after stimulation with Concanavalin A (Con A). A chromosome 14 aberration, inv(14) (q11-q32), may be of significance in the T-cell malignancy and may suggest a common clonal origin of the two tumors.

Chronic lymphocytic leukemia. Immunologic markers and functional properties of the leukemic cells

In 230 cases of chronic lymphocytic leukemia (CLL), marker analysis was performed with rosette techniques and a panel of xeno-antisera. A monoclonal B-cell proliferation was found in the majority of cases (94%). In most cases, the B-cells carried IgM, with or without IgD. Cytoplasmic immunoglobulin-inclusion bodies were seen in 7% of the cases of B-CLL. The number of patients with non-B/non-T-CLL was small (2%) in this series. In eight patients (4%), a proliferation of T-cells was established. These patients had a different clinical presentation and marker analysis of the lymphocytes, together with functional studies, showed that this group represented a mixture of different disease processes. Functional analysis of the B-CLL cells in 19 cases showed a poor or absent mitogen response and in nine cases the absence of the capacity to differentiate in vitro into plasma cells and/or to produce immunoglobulins.

Sézary syndrome with a 14:14 (q12:q31) translocation

The Sézary syndrome was diagnosed in a 71-year-old black woman with erythroderma, generalized lymphadenopathy and hepatosplenomegaly. The laboratory data revealed a white blood cell count of 65,000 mm3 with 81% lymphocytes, the majority having an indented or a cerebriform nucleus. The skin biopsy, the lymph node biopsy and immunologic surface marker studies confirmed the diagnosis of Sézary syndrome. The cytogenetic studies of the bone marrow and the peripheral blood revealed a (14:14) (q12:q31) translocation present, consistently in majority of the lymphocytes. This translocation is considered characteristic of ataxia-telangiectasia and, to our knowledge, has not been previously described in Sézary syndrome.

Spontaneous immunoglobulin changes in human plasma-cell dyscrasia

A series of spontaneous changes affecting the nature of the immunoglobulin secretion of plasma cels is described in a patient initially diagnosed as IgG lambda benign monoclonal gammopathy. After several years a slight increase in the amount of serum monoclonal immunoglobulin occurred; shortly thereafter an aggressive form of multiple myeloma was diagnosed. Unexpectedly a rapid spontaneous decrease of the monoclonal immunoglobulin, accompanied by the appearance in the serum of increasing quantities of a complex containing intact lambda light chains, then occurred. Concomitantly a fragment of the corresponding free light chain was was detected in the urine. A parallel is drawn between the facts observed in this patient and in an animal model recently proposed to explain the different types of structural immunoglobulin abnormalities in multiple myeloma.

Lymphocyte transformation in patients with cutaneous T-cell lymphomas

The proliferative responses of peripheral blood mononuclear cells from ten patients with cutaneous T-cell lymphoma were tested after stimulation with a variety of mitogens, including phytohemagglutinin (PHA), concanavalin A (Con A), pokeweed mitogen (PWM), staphylococcal protein A (SPA), and lymphocyte-conditioned medium (LyCM). Responses were measured by the incorporation of tritiated thymidine and by flow microfluorometry (FMF). In general, responses were depressed, although a broad range of responses were observed ranging from very poor to near normal responses. SPA and PWM were the most potent mitogens in the CTCL patients, unlike controls in whom PHA and SPA were the optimum mitogens and PWM was weakly mitogenic. FMF studies in two patients clearly demonstrated that aneuploid Sezary cells and not admixed normal lymphocytes were proliferating in response to SPA and PWM stimulation. The unusual pattern of mitogen responses found in these CTCL patients suggests Sezary cells may be derived from T-cell subpopulations with special affinity for SPA and PWM. The ability of FMF to demonstrate that aneuploid cells respond to mitogen stimulation makes it a useful additional technique in the evaluation of lymphocyte blastogenesis in patients with malignant lymphoproliferative disorders.

DNA content analysis by flow cytometry and cytogenetic analysis in mycosis fungoides and Sézary syndrome

Flow cytometric (FCM) analysis of DNA content was performed on 82 lymph node and peripheral blood specimens from 46 patients with mycosis fungoides and the Sézary syndrome. Overall, 32 of the 46 patients (70%) had aneuploidy detected by FCM. Aneuploidy was present in 63% of the patients at the time of diagnosis before systemic therapy. In these patients, aneuploidy was frequently detected in blood and lymph node specimens scored as negative by cytology and histology, suggesting that unsuspected extracutaneous dissemination is present in many patients at the time of diagnosis. Direct comparison with Giemsa-banded cytogenetic studies showed an excellent correlation of FCM results and cytogenetic chromosome number. However, FCM frequently detected a larger fraction of aneuploid cells, and mitogen-stimulation studies suggest this is the result of preferential stimulation of normal lymphocytes by phytohemagglutinin. Thus, mitogens with a preference for malignant T cells, such as staphylococcal protein A, should be used for cytogenetic analysis of malignant T-cell disorders. At diagnosis, some histologically positive specimens contained only diploid cells by FCM and cytogenetic analysis. These patients had a more indolent clinical course than patients with aneuploidy. Aneuploidy was detected by FCM as either wide G(1) or as discrete aneuploid peaks. The presence of aneuploidy at any time in the clinical course implied a poor prognosis. Discrete hyperdiploid peaks were associated with large cell histology, early relapse, and aggressive clinical course. The development of hyperdiploidy at relapse was documented in four patients and was associated with a transition to large cell histology and a poor prognosis. Similar studies may elucidate differences in natural history and mechanism for transition in histology in other lymphomas and solid tumors.

Chromosomes and Tumor Progression

Chromosome studies suggest that most neoplasms are unicellular in origin (i.e., "clones"), and that biological progression, typically associated with loss of "differentiated" properties, results from acquired genetic instability in the neoplastic population leading to sequential appearance of increasingly mutant subpopulations with greater selective growth advantage. In these circumstances acquisition by the tumor of an apparent "defect in maturation" could reflect either abnormal response to external growth regulators or loss ability to synthesize certain special differentiation products. Karyotypic data from a variety of mammalian neoplasms support both possibilities. The terminal accelerated phase of chronic granulocytic leukemia, for instance, in which undifferentiated blast cells replace a previously well-differentiated population, seems to represent emergence of a subline, often recognizable cytogenetically, in which an additionally altered response to growth regulation further shifts the balance between proliferation and differentiation at the stem cell level, so that undifferentiated (proliferating) cells come to predominate. In a case of chronic T cell leukemia, on the other hand, we have observed loss of certain specific T cell characteristics (membrane markers, response to mitogens) in conjunction with emergence of a chromosomally abnormal subclone, without alteration in the "mature" morphology of the neoplastic lymphocytes or any apparent change in their proliferation kinetics in vivo. Presumably, loss of these differentiated characteristics reflects alterations in specific gene functions within the neoplastic subpopulation, rather than any significant expansion in the undifferentiated stem cell pool. Cytogenetic studies may provide clues to the genetic basis of both types of "dedifferentiation.