The utility of hematopoietic stem cell karyotyping in the diagnosis of de novo myelodysplastic syndromes.

Myelodysplastic syndromes (MDS) are a clonal hematopoietic stem cell (HSC) disorders. Cytogenetics plays a vital role in pathogenesis, diagnosis, prognosis, and determining treatments in MDS. Cytogenetic studies on CD 34 cells in Asian MDS patients are limited. The aim of conducting this study was to compare the karyotypic features of CD 34 cells and their bone marrow (BM) karyotypes. BM samples of 20 primary MDS patients were collected. BM-CD 34 cells were isolated by CD34 positive selection. Conventional karyotyping was performed on primary BM samples and isolated CD 34 cells. Fluorescence in situ hybridization (FISH) was performed to confirm del(5q) by using XL 5q31/5q33 locus-specific probe. Chromosomal abnormalities were detected in 41 % (7/17) of BM and 40 % (8/20) of HSC karyotypes. BM and HSC karyotypes were similar (94 %) except in one (BM-normal; CD 34+ cells had del(5q)) where the patient showed characteristic del(5q) phenotype. The abnormalities found were del(5q)-10 % (2/20), del(11q)-5 % (1/20), del(12p)-5 % (1/20), 47,XY,+19-5 % (1/20), hypodiploidy-5 % (1/20), and random loss of chromosomes-10 % (2/20). The percentage of abnormal metaphases counted per case was higher for CD 34 cell cultures than for BM cultures. Culture failure were less for CD 34 cells when compared to BM. Sample limitation for BM does not apply for CD 34 cells if cultures can be maintained. Although the abnormal karyotypes counted were greater using CD 34 cells than BM, there was no statistically significant difference ( p > 0.05). Detection of karyotypic abnormalities could be greater when using CD 34 cells. All the karyotypic abnormalities reported in this study had been previously known in MDS. Further large scale studies are needed to verify our findings. [ABSTRACT FROM AUTHOR]