Cytogenetic Techniques in Haematology

Etiology and survival of aplastic anemia: a study based on clinical investigation

BACKGROUND

Management of aplastic anemia is etiology driven, whether constitutional or acquired. Age, gender, and severity of disease also play crucial role in the survival of aplastic anemia. Since, inadequate data are available from India, the present study was conducted with the aim to evaluate the etiology and survival of aplastic anemia.

METHODS

Three hundred patients were enrolled between May 2007 and April 2010. Severity analysis and chromosomal breakage study was performed and patients were followed up to calculate the survival rate.

RESULTS

Only 9.4% of the cases demonstrated the evidence of constitutional disease. Patients with acquired disease showed a significantly higher odd ratio for hepatitis. Overall survival was found to be independent of the gender and inherited etiology. Phenotype resembling to constitutional disease was present in only 22.22% (6/27) of patients. Similar ratio of the constitutional and acquired disease in both the age groups was observed.

CONCLUSION

Irrespective of the age and phenotype, chromosomal breakage study should be mandatory for all patients with aplastic anemia. Hepatitis as a preceding event may be associated with the cause of aplastic anemia. Young age and less severe disease were strongly associated with better survival. Lack of tertiary care facility in the country, time lag between diagnosis and treatment, and unaffordability to abide the treatment cost could be the major contributory factors for poorer survival.

Leukocyte concentration and the yields of metaphase cells in cultured peripheral blood of leukemic patients with hyperleukocytosis

The optimal concentration of leukocytes for maximizing the yields of metaphase cells was examined using PHA-stimulated and unstimulated peripheral blood cells of various leukemic patients with hyperleukocytosis, including 5 acute nonlymphocytic leukemias, 4 Ph-positive chronic myelocytic leukemias, one acute lymphoblastic leukemia, and one malignant lymphoma at a leukemic phase. The yields of metaphases reached maximum at leukocyte concentrations of either 1 X 10(6) or 2 X 10(6)/ml in both stimulated and unstimulated blood cultures of each patient, except for one patient with malignant lymphoma who exhibited no metaphases at any cell concentration level in the unstimulated culture. Metaphase yields in the stimulated and unstimulated cultures correlated with neither the percentages of blast cells and lymphocytes in the peripheral blood of the leukemia patients nor with the type of leukemia studied.

Studies of mitomycin C absorption after intravesical treatment of superficial bladder tumors

Mitomycin C is an active drug in the treatment of superficial bladder cancer. Although clinical safety of intravesical mitomycin C has been well accepted there are no data on absorption of this drug from the bladder in patients with damaged bladder mucosa. We studied 18 patients for evidence of absorption of mitomycin C after transurethral resection and/or radiation therapy. Mitomycin C is absorbed on intravesical instillation and the degree of absorption depends on the degree of damage to the bladder. Despite some evidence of absorption no systemic effect on bone marrow was observed and no evidence of deoxyribonucleic acid damage was found in any of these patients. Mitomycin C appears to be a safe drug but further studies are indicated to document its safety when used for maintenance therapy.

Chromosome analysis in hematologic disorders. The leukemias

For two decades, cytogenetic studies have been used to rule in (or out) the Philadelphia (Ph1) chromosome associated with chronic myeloid leukemia. Beyond this single purpose, chromosome studies have generally not been utilized in or applied to the practice of hematology-oncology. This report presents male and female patients, teens to 70s in age, with representative hematologic disorders, in whom the cytogenetic findings were useful clinically. These cases illustrate the following principles: (1) hematologic disorders can be characterized by chromosome analysis; (2) chromosome findings help in the diagnosis, prognosis, and treatment of blood diseases; (3) blood and bone marrow samples can be processed routinely for cytogenetic analysis; (4) these samples can be transported long distances from clinic to laboratory; and (5) the contemporary practice of hematology and oncology requires chromosome analysis for fuller evaluation and understanding of hematologic conditions.

Cytogenetic study in acute myeloid leukaemia using peripheral blood samples sent by post

The patterns of chromosomal abnormalities in acute myeloid leukaemia (AML) revealed by study of peripheral blood specimens (group A) up to seven days old were comparable to the results from fresh bone marrow (group B). However, a decreasing proportion of cases providing enough metaphases for study, an increasing proportion of cases with chromosomal abnormalities, a decreasing ratio AN:AN + AA (see footnote Table 1) and a decreasing percentage of chromosomally normal cells in AN cases were found with ageing of specimens, which clearly demonstrates that cells with a normal karyotype were more likely to lose the capacity for dividing and die off than abnormal ones during ageing of specimens. Since the cells in older specimens were less active in division, a prolonged culture time was used. The different times for the cells from older specimens to re-enter active proliferation in culture conditions appeared to have some cytobiological significance. Three cases with t(8q-; 21q+) were present in group A but none in group B. Two cases of APL both showed a t(15q+; 17q-) and the breakpoints seemed to be at 15q24 and 17q22. One case showed trisomy 8 and double minute chromosomes. The remission rate in AN patients was lower than in AA or NN patients.

New chromosome techniques in the study of human neoplasia

Amethopterin synchronization of bone marrow and lymph node cells makes it possible to obtain well banded and elongated metaphases and prometaphases in the majority of patients with leukemia and lymphoma. Chromosomal analysis of most neoplasias is also possible through the use of mild tumor cell disaggregation methods, short term culture on feeder layers, and special media that help in the preferential proliferation of cancer cells. In the past, only about half of all patients with acute leukemia and lymphoma could be shown to have a chromosomal defect, and only a small proportion of solid tumors could be analyzed. With the new technology, abnormal tissue from the majority of cancer patients can be successfully studied and chromosomal abnormalities detected.