title: DNA Ploidy and S-phase Fraction Analysis in Paediatric B-cell Acute Lymphoblastic Leukemia Cases: a Tertiary Care Centre Experience.
abstract: DNA ploidy is an important prognostic parameter in paediatric B-ALL, but the significance of the S-phase fraction is unclear. In present study, DNA ploidy was assessed in 40 pediatric B-ALL cases by flow cytometry. The DI (DNA index) and percentage of cells in S-phase were calculated using Modfit software. Aneuploidy was noted in 26/40 (65%) cases. A DI of 1.10-1.6 (hyperdiploidy B) was noted in 20/40 (50%) and 6/40 (15%) had a DI>1.60 (triploid and tetraploid range). Some 14/40 (35%) cases had a diploid DI between 0.90-1.05. None of the cases had a DI <0.90 (hypodiploid) or in the 1.06-1.09 (hyperdiploid A) range. The mean S-phase fraction was 2.6%, with 24/40 (60%) having low and 16/40 (40%) high S-phase fractions. No correlation was noted with standard ALL risk and treatment response factors with DI values or S-phase data, except for a positive correlation of low S-phase with high NCI risk category (p=0.032). Overall frequency of hyperdiploidy in our cohort of B-ALL patients was very high (65%). No correlation between hyperdiploidy B and low TLC or common B-phenotype was observed in our study as 42% cases with DI 1.10-1.6 had TLC> 50 x 109 and 57.1% CD 10 negativity. The study also highlighted that S-phase fraction analysis does not add any prognostic information and is not a useful parameter for assessment in ALL cases. However, larger studies with long term outcome analysis are needed to derive definitive conclusions.
authors.affiliation: Department of Pediatrics, All India Institute of Medical Sciences, New Delhi, India E-mail : prateekbhatia@rediffmail.com.
authors.forename: Banothu Kiran
authors.initials: BK
authors.lastname: Kumar
authors.forename: Prateek
authors.initials: P
authors.lastname: Bhatia
authors.forename: Amita
authors.initials: A
authors.lastname: Trehan
authors.forename: Ajit Pal
authors.initials: AP
authors.lastname: Singh
authors.forename: Deepak
authors.initials: D
authors.lastname: Kaul
authors.forename: Deepak
authors.initials: D
authors.lastname: Bansal
mesh_terms: D000782:Aneuploidy; D001402:B-Lymphocytes / Q000473:pathology; D002648:Child; D002675:Child, Preschool; D004273:DNA, Neoplasm / Q000235:genetics*; D005260:Female; D005434:Flow Cytometry; D018628:Gene Dosage / Q000235:genetics*; D006801:Humans; D007223:Infant; D008297:Male; D015452:Precursor B-Cell Lymphoblastic Leukemia-Lymphoma / Q000235:genetics*; D016196:S Phase / Q000235:genetics*; D062606:Tertiary Care Centers; D057891:Tetraploidy; D057885:Triploidy
chemical_list: D004273:DNA, Neoplasm