Cytogenetic and immunologic study in chronic leukemia

ABSTRACT

Cytogenetic study of peripheral blood and bone marrow aspirate as well as HLA typing were done in 17 patients with chronic myeloid leukemia [CML] and 14 patients with chronic lymphocytic leukemia [CLL]. Chromosomal studies of phytohemagglutinin stimulated lymphocytes usually reveal normal karyotype. Clonal chromosomal aberrations are revealed in about half of the patients if lymphocyte cultures are stimulated by B-cell mitogen such as pokeweed mitogen and other polyclonal mitogens. In CML, the most common abnormality was the presence of Philadelphia chromosome [Ph1] which was found in 88% of the cases Additional chromosomal abnormalities were found in 47% of the patients, including deletions, breaks, duplication of X- chromosome and monosomy 6. These aberrations were found in patients in the accelerated phase or in the blastic phase of the disease. Ph1 negative patients were found to have more aggressive course of the disease, while the presence of a single Ph1 carries a better prognosis. In patients with CLL, only one patient had monosomy 7 and another one had monosomy 8 and 10 patients showed normal karyotype, while the cytogenetic study failed in two patients. As regards HLA typing, CML patients have significantly high frequency of the specificities HLA- A9, CW3, and CW4, whereas the frequency of HLA-AW19 was decreased significantly as compared to the typing of 100 normal random individuals from the same population. In patients with CLL, there was a significantly high relative risk of the phenotypes HLA-B8, B14, and A9 as compared to those in controls. The present study revealed the importance of cytogenetic studies in the diagnosis, classification, course and prognosis of leukemic patients. The appearance of aneuploid metaphases in a previously diploid marrow may herald imminent relapse of the disease and may be used for diagnostic purposes in cases in which other parameters are confusing. The cytogenetic data when combined with clinical data can preferably predict an impending transformation in chronic leukemia patients. The appearance of additional chromosomal aberrations together with Ph1 denotes disease metamorphosis whether to accelerated phase or actual blastic crisis. The presence of chromosome aberrations in patients with CLL denotes advanced disease stage or resistance to therapy, while normal karyotype carries a better prognosis