Frequency of Cytogenetic abnormalities in patients of acute Myeloid Leukemia

Abstract

Introduction: Cytogenetic analysis performed at diagnosis is considered to be the most valuable prognostic factor in acute myeloid leukaemia (AML). Cytogenetic abnormalities which indicate a good prognosis include t(8; 21), inv(16) and t(15;17). Normal cytogenetics carries average risk in AML. Patients with AML that is characterized by deletions of the long arms or monosomies of chromosome 5 or 7 or by abnormalities of 11q23 have particularly poor prognosis. Objective: To determine the frequency and type of cytogenetic abnormalities in Pakistani patients of AML. Design: Descriptive study. Subjects and Methods: Thirty six patients of acute myeloid leukaemia were referred to the department of Heamatology, Armed Forces Institute of Pathology, Rawalpindi for cytogenetic studies during the period from March 2001 to September 2004. Five ml of venous blood was collected by venesection in vacutainer containing sodium heparin as anticoagulant. Blood was cultured on RPMI-1640 medium enriched with L-glutamine and foetal bovine serum. Phytohaemagglutin was used as T-cell mitogen. The cultures were incubated for 72 hours at 37°C. Mitoses were arrested in metaphases by colchicine. The cells were harvested and slides were made. Slides were aged and trypsin digestion was done. Slides were stained with Giemsa stain. Twenty metaphases were analysed under the microscope and the observations were recorded. Results: In 10 patients` culture failed to yield evaluable metaphases. Out of 26 evaluated patients, cytogenetic abnormalities carrying good prognosis were seen in 6(23%) patients t(8;21) in 3 cases, t(15;17) in 2 and inv(16) in one patient. Normal karyotype carrying standard risk was seen in 17(65.4%) patients. Whereas abnormalities carrying poor prognosis were seen in only 3(11.6%) patients. These comprised 2 cases of trisomy 8 and one of dup (3)(q21; q26). Conclusion: This study reveals that majority of Pakistani patients with AML belong to good (23%) or standard (65.4%) risk groups. Only 11.6% patients belong to poor risk group