[Analysis of in vitro characteristics of colony-forming cells in myelodysplastic syndrome and comparison with that in non-severe aplastic anemia].

ABSTRACT

OBJECTIVE: To investigate in vitro characteristics of colony-forming cells (CFC) in patients with myelodysplastic syndrome (MDS) and to compare that in patients with non-severe aplastic anemia (NSAA). METHODS: Data of in vitro CFC and correlation with other related laboratory tests in 155 newly diagnosed MDS patients were analyzed retrospectively, and to compare with data of in vitro CFC in 122 newly diagnosed NSAA patients. RESULTS: Median number of burst-forming units-erythroid (BFU-E) was 9 (0 - 157)/10(5) bone marrow mononuclear cells (BMMNC), colony forming unit-erythroid (CFU-E) 30 (0 - 425)/10(5)BMMNC and colony forming unit-granulocytes/macrophages (CFU-GM) 14 (0 - 125)/10(5)BMMNC in patients with MDS, being significantly lower than those in healthy control; number of BFU-E and/or CFU-E was lower than the lower limit of normal control in 66 cases (42.6%), CFU-GM lower in 3 cases (1.9%) and BFU-E and/or CFU-E with CFU-GM lower in 70 cases (45.2%). Cluster/CFU-GM ratio was significantly lower in low blast group (MDS < 5% blast in bone marrow smear) than that in high blast group (MDS ≥ 5% blast) (0.65 vs 1.0, P = 0.049). In all MDS patients, cluster had positive correlation with each type of CFC (r = 0.415, 0.338, 0.642 for BFU-E, CFU-E, CFU-GM, respectively, P = 0.000), but had negative correlation with neutrophil alkaline phosphatase (N-ALP) positive rate and scores (r(rate) = -0.315, P = 0.001 and r(scores) = -0.257, P = 0.006). The median number of each type of CFC was significantly higher in MDS group than that in NSAA group (BFU-E 9 vs 5/10(5)BMMNC, P = 0.017; CFU-E 30 vs 19.5/10(5)BMMNC, P = 0.023; CFU-GM 14 vs 10/10(5)BMMNC, P = 0.003, respectively). Positive correlation between BFU-E and CFU-E were revealed in both MDS and NSAA group (r(MDS) = 0.712, P = 0.000 and r(NSAA) = 0.757, P = 0.000), with a lower correlation coefficient in MDS (P < 0.05). CONCLUSIONS: Early onset MDS present markedly decreased hematopoietic progenitor cells (HPC), and particularly in erythroid progenitors extensively and severely. The number of BFU-E, CFU-E and CFU-GM can reflect HPC number in vivo but not stand for normal hematopoietic clones, the number of clusters represent pathologic HPC clones but not exactly leukemic blasts.