Preleukemic syndromes.

Acute nonlymphocytic leukemia (ANLL) is preceded by a hematologic illness representing the "preclinical" stages of the disease in many patients. This "preclinical stage" or preleukemic stage is difficult to recognize by conventional hematologic morphologic techniques. A prospective study was carried out to determine whether cytogenetic studies would be helpful in the recognition of preleukemic states and whether the presence of cytogenetic abnormalities would have prognostic significance. A study of 284 patients with suspected preleukemia has yielded 62 patients with progression to overt ANLL. Cytogenetic abnormalities were found in 30% of suspected preleukemic patients, whereas 53% of the patients progressing to acute leukemia had cytogenetic abnormalities. These studies show that the presence of cytogenetic abnormalities aid in the recognition of preleukemia but are not specific for early leukemia. Patients with cytogenetic abnormalities are more likely to develop overt ANLL. Banded chromosome studies demonstrated cytogenetic abnormalities in the preleukemic phase in 13 of 26 patients. A variety of clonal chromosomal abnormalities were observed.     

Micronucleus test applied in patients with acute leukemia, before and at different intervals during the cytostatic treatment

The micronucleus test was applied in a group of 36 patients with malignant disease of the blood (acute lymphoblastic leukemia, ALL, and acute non-lymphocytic leukemia, ANLL) in order to evaluate to what extent it may be relevant for the efficiency of the cytostatic treatment. To this end, the test was applied at the onset of the disease (when diagnosed) and at different intervals after initiating the cytostatic therapy. Determination of the incidence of micronucleated cells and immature cells (blasts) at the two moments of the study established a correlation between the frequency of micronucleated cells and blast cells, the response to the anticancerous treatment and survival duration, the data obtained reflecting the prognostic value of the test in some malignant hemopathies.     

The database for analysis of quantitative characteristics of chromosome aberration frequencies in the culture of human peripheral blood lymphocytes]

The data on spontaneous chromosome aberration rates in cultures of human peripheral blood lymphocytes obtained in the past 30 years have been collected to form a database. The database contains the results of analysis of more than 330,000 metaphases in lymphocytes from more than 1200 subjects. The frequency of aberrant metaphases in the control group has been estimated at 0.0213 +/- 0.00085. No differences between sexes have been found with respect to either the total chromosome aberration rate or the rates of individual aberration types. The total chromosome aberration rate did not depend on age; however, it has been found that the number of fragments increased and the number of exchanges decreased with age. Smoking has been found to increase the frequency of chromosome aberrations in individuals with occupational hazards, but not in those who are not occupationally exposed to radiation or chemicals. Alcohol consumption increased the frequency of paired fragments, whereas the frequencies of other aberrations did not differ from the control values.     

The Database for Analysis of Quantitative Characteristics of Chromosome Aberration Frequencies in the Culture of Human Peripheral Blood Lymphocytes

The data on spontaneous chromosome aberration rates in cultures of human peripheral blood lymphocytes obtained in the past 30 years have been collected to form a database. The database contains the results of analysis of more than 330 000 metaphases in lymphocytes from more than 1200 subjects. The frequency of aberrant metaphases in the control group has been estimated at 0.0213 ± 0.00085. No differences between sexes have been found with respect to either the total chromosome aberration rate or the rates of individual aberration types. The total chromosome aberration rate did not depend on age; however, it has been found that the number of fragments increased and the number of exchanges decreased with age. Smoking has been found to increase the frequency of chromosome aberrations in individuals with occupational hazards, but not in those who are not occupationally exposed to radiation or chemicals. Alcohol consumption increased the frequency of paired fragments, whereas the frequencies of other aberrations did not differ from the control values.     

Cytogenetic findings in acute myelogenous leukemias (FAB M 1 to M 6)

The results published in the period from 1973 to 1983 entitled "Cytogenetic findings in acute myeloic leukemias" (M 1 to M 6 of FAB classification) were compiled. In 50-60 per cent of those patients affected with acute myeloic leukemia a deviating karyotype could be detected. With a markedly higher frequency chromosomes 8 and 21 will take part in aberrations, with translocations (8; 21) having the main share with about 30-40 per cent. More than half the male bearers of translocation exhibits a loss of the Y-chromosome, a third of female patients a loss of the X-chromosome. Trisomy 8 and 9 as well as monosomy 7 appear in about 20 per cent. These aberrations can also be found in all other leukemic and preleukemic processes. Patients with karyotypic abnormalities in all their cells will have the slightest average survival time and the worst appeal to therapy. The sole appearance of monosomy 7 or Ph1-chromosome respectively seems to be an unfavourable sign from a prognostic point of view. Children with acute myeloic leukemia will possess an aberrant karyotype more frequently than adults, but they have a longer average life, boys are more frequently affected by this. Acute promyelocytic leukemia can be characterized cytogenetically in 94 per cent of the cases by translocation (15; 17). However, distinct geographical differences can be observed here, the causes of which have not been elucidated. About 40 per cent of the patients with acute myelo-monocytic leukemia developed aberrations. Further investigations will have to show whether the chromosome 11 really took part in it somewhat more frequently than merely at random. Chromosome anomalies have not a visible influence on the course of the disease. In 30-40 per cent of patients with a rarely occurring acute monocytic leukemia, an abnormal karyotype could be found. There was an incidence of 47 per cent for a specific translocation (9; 11) or a similar variant respectively. Erythroleukemia is characterized by a high instability of chromosomes and karyotypical variability, particularly in erythrocyte precursors and by an average survival time of one months. Megakaryoblastic and eosinophilic leukemia are very rare kinds of acute leukemias. The small number of publications allows no general statement to be made concerning karyotypical changes.     

Clinical implications of chromosome abnormalities in acute non-lymphocytic leukemia: current status.

Data currently available on banded chromosome studies on patients with ANLL suggest that the presence of a chromosome abnormality in such patients indicates a poor prognosis, and that different treatment strategies need to be developed for these patients. However, patients with at least one normal metaphase survive nearly as long as those with only normal metaphases. A specific chromosome abnormality in APL [t(15;17)], an unusual association of a translocation [t(8;21)] in association with loss of a sex chromosome, and a rare association of thrombocytosis and a chromosome insertion (3;3 ins), suggest that some chromosome changes in ANLL are specific.     

Chromosome studies in polycythemia vera.

Polycythemia vera (PV) represents an apparent monoclonal stem cell proliferation with a frequent transition to full neoplastic behavior. Up to 26% of untreated PV patients can be expected to have some chromosome abnormalities in the marrow at the time of diagnosis, and 10--15% have an abnormal cell line or clone. Both structural and numerical aberrations occur. Aneuploidy is the most common type of chromosome abnormality, however, with hyperdiploid clones occurring more frequently than hypodiploid clones. Chromosomes 1, 8, 9 and 20 are involved in a non-random pattern, and aberrations of all the F group, or at least the No. 20 chromosome seem to be associated to some extent with diseases involving erythroid hyperplasia. Leukemia develops in a certain percentage of patients regardless of the type of treatment they have received, but the relationship, if any, between the chromosome abnormalities and the development of leukemia is still uncertain. The abnormal clones that occur in PV appear to be quite stable and there is no indication at this time that they correlate with a prognosis of leukemic transformation.     

Inactivated X chromosome fold in human leukemia and related clonal disorders

Summary A disturbance of the X chromosome inactivation process has been demonstrated in some human tumors. In order to study this phenomenon in leukemia, the site of unusually frequent folding in Xq13-q21 was used as a morphological marker. A total of 858 GTG-banded mitoses from 61 women with different hematological malignancies were analyzed, 35 of them with normal karyotype and 26 with chromosome aberrations. The folding patterns and the fold percentage remained unchanged in our patients. Using this marker, X-inactivation could easily be verified in leukemia and related disorders on routine preparations.     

The effect of low-dose irradiation and of age on the in vitro radiosensitivity of human lymphocytes

The effect of low-dose irradiation and of age on the radiosensitivity of human lymphocytes was studies in two groups: control (67 people) and exposed to uncontrolled low-dose irradiation in past (165 people). Radiosensitivity of lymphocytes was estimated by the level of chromosome aberrations induced in vitro by gamma-radiation Cs137 at the dose 1.5 Gy. In exposed children the frequency of induced chromosome aberrations was higher and in the exposed adults--lower in comparison to the coresponding controls. To investigate an age response of the number of chromosome aberrations three statistical approaches were used: the correlation analysis of individual data, the correlation analysis of means for 10-years intervals, the comparison of 3 age groups. In control group no significant alteration in the level of induced chromosome aberrations with age was found. However the significant negative correlation between these two parameters was revealed in exposed group, which likely is due to the opposite direction of differences in radiosensitivity of exposed children and adults from the corresponding controls.     

Quantitative characteristics of the frequency of chromosomal aberrations in a group of residents of a large western Siberian industrial region

The results of a 15-year study of chromosome aberration frequency in cultured peripheral blood lymphocytes from subjects living in the Kuzbass industrial region are presented. The database for the analysis of the main parameters of chromosome aberrations contains data on 925 subjects, with the total number of cells examined being 92,900. It has been found that the total frequency of aberrant metaphases in the database is 3.73 +/- 0.1%, whereas this frequency for the sample of subjects from industrial areas of this region (the basic control group) is significantly lower (2.86 +/- 0.26%). It has been demonstrated that the sex and age of the subjects do not affect substantially the frequency of any type of chromosome aberrations. Tobacco smoking is associated with a slight increase in chromosome damage frequency; however, the difference between smokers and nonsmokers is insignificant even among subjects exposed to occupational hazards. The possible causes that have determined the increased basic and background chromosome aberration frequencies in the population of the Kemerovo oblast compared to these parameters for the European part of Russia and the CIS are discussed.     

Analysis of the Chromosome Aberrations Induced by X-Rays in Somatic Cells of DROSOPHILA MELANOGASTER

A technique has been perfected for enabling good microscope preparations to be obtained from the larval ganglia of Drosophila melanogaster. This system was then tested with X-rays and an extensive series of data was obtained on the chromosome aberrations induced in the various stages of the cell cycle.-The analysis of the results obtained offers the following points of interest: (1) There exists a difference in radio-sensitivity between the two sexes. The females constantly display a greater frequency of both chromosome and chromatid aberrations. They also display a greater frequency of spontaneous aberrations. (2) In both sexes the overall chromosome damage is greater in cells irradiated in stages G(2) and G(1). These two peaks of greater radiosensitivity are produced by a high frequency of terminal deletions and chromatid exchanges and by a high frequency of dicentrics, respectively. (3) The aberrations are not distributed at random among the various chromosomes. On the average, the Y chromosome is found to be more resistant and the breaks are preferentially localized in the pericentromeric heterochromatin of the X chromosome and of the autosomes. (4) Somatic pairing influences the frequency and type of the chromosome aberrations induced. In this system, such an arrangement of the chromosomes results in a high frequency of exchanges and dicentrics between homologous chromosomes and a low frequency of scorable translocations. Moreover, somatic pairing, probably by preventing the formation of looped regions in the interphase chromosomes, results in the almost total absence of intrachanges at both chromosome and chromatid level.     

Acute myelomonocytic leukemia with involvement of eosinophils and inversion of chromosome 16

A case of acute nonlymphocytic leukemia (ANLL) with abnormal marrow eosinophils is presented. Thorough morphological, cytochemical, and cytogenetic studies confirm the existence of a recently defined new cytogenetic-morphological entity: acute myelomonocytic leukemia with abnormal bone marrow eosinophils (FAB M4), chloracetate esterase- and periodic acid-Schiff-positivity of eosinophilic granules, and pericentric inversion of chromosome 16, in this case combined with trisomy 8. So far 18 such cases have been reported from a single institution. The implications of this new association on the diagnosis of acute leukemia with abnormal eosinophils are discussed.     

The evaluation of prognostic factors for achieving complete remission and survival in ANLL of adults. The proposition of a prognostic scale.

The retrospective analysis has concerned 323 patients with acute nonlymphocytic leukaemia (ANLL). The comparable patients groups were treated since 1981 according to protocols used by the Polish Acute Leukaemia Group (induction; modified TAD or Adriamycin plus Ara-C, maintenance; rotatingly changed polychemotherapy for 3 years). The prognostic value for achieving complete remission (CR) and survival of 67 pre-treatment factors (42 quantitative and 25 qualitative) was evaluated. The most important 9 parameters were scored according to the prognostic value as follows: age, proportion of blasts in bone marrow, blast count in peripheral blood, morphological subtype, percentage of granulocytes in bone marrow, proportion of blasts with CD-15 antigen, thrombocyte count, spleen/liver enlargement, protein concentration in cerebro-spinal fluid. The scoring system has been elaborated allowing selection of ANLL patients to standard risk group and a high risk group.     

Chromosome aberrations in relation to radiation dose following partial-body exposures in three populations

Structural chromosome aberrations were evaluated in peripheral blood samples obtained from three populations exposed to partial-body irradiation. These included 143 persons who received radiotherapy for enlarged thymus glands during infancy and 50 sibling controls; 79 persons irradiated for enlarged tonsils and 81 persons surgically treated for the same condition during childhood; and 77 women frequently exposed as young adults to fluoroscopic chest X rays during lung collapse treatment for tuberculosis (TB) and 66 women of similar ages treated for TB with other therapies. Radiation exposures occurred 30 and more years before blood was drawn. Doses to active bone marrow averaged over the entire body were 21, 6, and 14 cGy for the exposed thymic, tonsil, and TB subjects, respectively. Two hundred metaphases were scored for each subject, and the frequencies of symmetrical (stable) and asymmetrical (unstable) chromosome aberrations were quantified in 97,200 metaphases. Cells with stable aberrations were detected with greater frequency in the irradiated subjects compared with nonirradiated subjects in all three populations, and an overall test for an association between stable aberrations and partial-body ionizing radiation was highly significant (P less than 0.001). We found no evidence that radiation-induced aberrations varied by age at exposure. These data show that exposure of children or young adults to partial-body fractionated radiation can result in detectable increased frequencies of stable chromosome aberrations in circulating lymphocytes 30 years later, and that these aberrations appear to be informative as biological markers of population exposure.     

Genetic aspects of nonchromaffin paraganglioma

Summary Sister chromatid exchanges (SCE) and structural chromosome aberrations were analyzed in peripheral blood lymphocytes of 100 individuals, and correlated to age and sex. No correlation was found between the frequency of SCE and age, but older individuals had significantly more structural aberrations than younger. Females had significantly more SCE as well as structural chromosome aberrations than males. The positive correlations of SCE and structural aberrations to age and sex were also significant when these factors, as well as smoking habits, were taken into consideration in an analysis of covariance.     

Quantitative Characteristics of Chromosome Aberration Frequency in the Human Population of a Large Western Siberian Industrial Region

The results of a 15-year study of chromosome aberration frequency in cultured peripheral blood lymphocytes from subjects living in the Kuzbass industrial region are presented. The database for the analysis of the main parameters of chromosome aberrations contains data on 925 subjects, with the total number of cells examined being 92 900. It has been found that the total frequency of aberrant metaphases in the database is 3.73 ± 0.1%, whereas this frequency for the sample of subjects from industrial areas of this region (the basic control group) is significantly lower (2.86 ± 0.26%). It has been demonstrated that the sex and age of the subjects do not affect substantially the frequency of any type of chromosome aberrations. Tobacco smoking is associated with a slight increase in chromosome damage frequency; however, the difference between smokers and nonsmokers is insignificant even among subjects exposed to occupational hazards. The possible causes that have determined the increased basic and background chromosome aberration frequencies in the population of the Kemerovo oblast compared to these parameters for the European part of Russia and the CIS are discussed.     

Cytogenetic and FISH findings are complementary in childhood ALL

Primary genetic abnormalities of leukemia cells have important prognostic significance in childhood acute leukemia. In the last two years 30 newly diagnosed or recurrent childhood ALL bone marrow samples were analyzed for chromosomal abnormalities with conventional G-banding and interphase-fluorescence in situ hybridization (I-FISH) using probes to detect BCR/ABL fusions, cryptic TEL/AML1 and MLL rearrangements and p16(9p21) tumor suppressor gene deletions. G-banded karyotype analysis found clonal chromosomal aberrations in 50% of cases. With the use of complementary I-FISH techniques, ALL-specific structural and numerical changes could be identified in 70% of the patients. Nine cases (30%) had subtle chromosomal aberrations with prognostic importance that had not been detected in G-banded analysis. Conventional G-banding yielded additional information (rare and complex structural aberrations) in 19% of patients. The most common aberration (30%) was AML1 copy number increase present in G-banded hyperdiploid karyotype as a chromosome 21 tetrasomy in the majority of cases; one case displayed 5-6 copies and in another case amplification of AML1 gene on der(21) was combined with TEL/AML1 fusion of the homologue AML1 gene and deletion of the remaining TEL allele. High hiperdiploidy was detected in 6 cases, in one patient with normal G-banding karyotype. TEL/AML1 fusion signals were identified in four patients. Deletion of p16 locus was found in eight cases (23%), of which only two had cytogenetically visible rearrangements. G-banding in combination with I-FISH has produced major improvements in the sensitivity and accuracy of cytogenetic analysis of ALL patients and this method helps to achieve a more precise identification of different risk categories in order to choose the optimal treatment.     

Trisomy 8 in leukemia: A GCRI experience

Trisomy of chromosome 8 is frequently reported in myeloid lineage disorders and also detected in lymphoid neoplasms as well as solid tumors suggesting its role in neoplastic progression in general. It is likely to be a disease-modulating secondary event with underlying cryptic aberrations as it has been frequently reported in addition to known abnormalities contributing to clinical heterogeneity and modifying prognosis. Here, we share our findings of trisomy 8 in leukemia patients referred for diagnostic and prognostic cytogenetic assessment. Total 60 cases of trisomy 8, as a sole anomaly or in addition to other chromosomal aberrations, were reported (January 2005-September 2008). Unstimulated bone marrow or blood samples were cultured, followed by GTG banding and karyotyping as per the ISCN 2005. Patients with +8 were chronic myeloid leukemia (CML) (36), acute myeloid leukemia (AML) (17), and acute lymphoblastic leukemia (ALL) (7). In 7 patients, trisomy 8 was the sole anomaly, whereas in 6 patients +8 was in addition to normal clone, in 47 patients, the +8 was in addition to t(9;22), t(15;17), and others, including 3 with tetrasomy 8. Only one patient showed constitutional +8. The present study will form the basis of further cumulative studies to correlate potential differential effects of various karyotypic anomalies on disease progression and survival following a therapeutic regime. To unravel the role of extra 8 chromosome, constitutional chromosomal analysis and uniparental disomy will be considered.     

Humoral factors of "spontaneous" mutagenesis in mammals and man

The frequency of chromosome aberrations in bone-marrow cells of mice in tissue incompatibility conflicts, and in the lymphocytes of the peripheral blood of 20 patients suffering from different allergies was studied. It was established that in mice, during allograft rejection, i.e. on the 10th–15th days after grafting of allogeneic skin, the frequency of cells with chromosome aberrations increases significantly up to 12–15% against 4–5% in the control. On the 20th day after grafting, the level of chromosome aberrations falls back to the control level. In allergic patients the frequency of cells with chromosome aberrations was 10.7% (4–22%). In numerous control subjects this value did not exceed 2%. The highest level of aberrations was found during the acute stage of the disease especially in patients in the state of anaphylactic shock. No correlation was found between the frequency of aberrant cells and the action of definite allergens. The problem of the possibility of extending the above described phenomenon to non-immunocompetent cells of mammals, and of the role of immunological stress in spontaneous mutagenesis are discussed.     

Hybridization between Viola canina and V. persicifolia in Norway

Hybridization in Norway between Viola canina and V persicifolia was investigated by analysis of root tip mitosis, pollen stainability and morphological variation. The chromosome number was proved to be 2n = 40 (tetraploid) for V. canina ssp. montana , 2n = 20 (diploid) for V. persicifolia and 2n = 30 (triploid) for the hybrid, V. canina × persicifolia . No deviating chromosome numbers were found. The tetraploids and the diploids had a high frequency, and the triploids a low frequency, of apparently good pollen grains. Canonical variate analysis were used to investigate the pattern of morphological differentiation in the material. The specimens clearly separate into three groups in accordance with the three ploidy levels. No introgression was demonstrated.