Flow cytometric characterization of phenotype, DNA indices and p53 gene expression in 55 cases of acute leukemia.
OBJECTIVE
To characterize the phenotype of acute leukemia cases using flow cytometry, to detect mixed lineage cases and to use DNA index determination, including S-phase fraction (SPF) and p53 detection, to find if there was any correlation of SPF and p53 expression with outcome.


METHODS
Fifty-five cases of acute leukemia were enrolled in this study. A complete hemogram and routine bone marrow examination, including cytochemistry, was done. Mycloperoxidase-negative cases were evaluated on a flow cytometer using monoclonal antibodies. DNA indices were determined by flow cytometry in all cases, and p53 was detected immunohistochemically using the alkaline phosphatase/antialkaline phosphatase technique.


RESULTS
Acute myeloblastic leukemia (AML) was diagnosed in 32 cases; acute lymphoblastic leukemia (ALL) was diagnosed in 18 (14 B lineage and 4 T line age). Four cases showed mixed lineage leukemia, and undifferentiated acute leukemia was diagnosed in one case. The mean/range of SPF for these groups were 3.76/0.33-6.91, 6.25/0.15-21.4, 2.89/0.35-10.64, 2.60/0.72-6.94 and 7.34, respectively. Aneuploidy was detected in two cases of B-lineage ALL and tetraploidy in a case of AML-M7, while all others were diploid p53. Was detected in 6 of 55 cases (10.90%). Follow-up was available for 24 patients. Five patients relapsed, and four had B-cell type ALL and were diploid and expressed no p53 gene. SPF% did not show any correlation with outcome.


CONCLUSIONS
These data suggest that within acute leukemia subtypes, there is a wide variation in SPF. SPF does not seem to correlate with outcome. Immunophenotyping is essential to determine the lineage in myeloperoxidase-negative cases. It is perhaps the only way to diagnose mixed lineage leukemia and aberrant expression of markers presently. The p53 gene was detected less frequently. However, more studies are required from different centers with longer follow-up to evaluate prognostic significance.
Powari
Manish
M
Department of Haematology, Postgraduate Institute of Medical Education and Research, Chandigarh, India.
Varma
Neelam
N
Varma
Subhash
S
Marwaha
Ram Kumar
RK
Sandhu
Harpreet
H
Ganguly
Nirmal Kumar
NK
D000293:Adolescent; D000368:Aged; D015703:Antigens, CD / Q000032:analysis / Q000145:classification; D002648:Child; D004273:DNA, Neoplasm / Q000032:analysis*; D005260:Female; D005434:Flow Cytometry / Q000379:methods*; D005500:Follow-Up Studies; D015870:Gene Expression; D016158:Genes, p53; D006801:Humans; D016130:Immunophenotyping; D007223:Infant; D015470:Leukemia, Myeloid, Acute / Q000145:classification / Q000175:diagnosis*; D008297:Male; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000145:classification / Q000175:diagnosis*; D016159:Tumor Suppressor Protein p53 / Q000235:genetics / Q000378:metabolism*
D015703:Antigens, CD; D004273:DNA, Neoplasm; D016159:Tumor Suppressor Protein p53