OBJECTIVETo investigate the abnormal hematopoietic clone burden of the patients with myelodysplastic syndromes (MDS) and its clinical implication.

METHODSThe ratio of the metaphase with abnormal karyotypes to the total was regarded as the index of MDS clonal burden. Thirteen parameters were assayed and the correlations between these parameters and MDS clone burden were analysed.

RESULTSThe clonal burden of MDS patients was (67.4 +/- 36.2)%. It correlated positively with bone marrow blasts (r = 0.483, P < 0.05), negatively with hemoglobin level (r = -0.445, P < 0.05). The number of blasts, hemoglobin and erythrocytes in high clonal burden (>50%) and low clonal burden (< or = 50%) groups were significantly different (P < 0.05). CD4+ T lymphocytes of MDS patients and normal controls were (274.18 +/-71.85) x 10(6)/L and (454.82 +/- 205.88) x 10(6)/L (P < 0.05) respectively. CD8+ T lymphocytes between MDS patients and normal controls had no difference. The serum level of IL-2 of MDS patients and normal control groups were (6.29 +/- 3.58) g/L and (3.11 +/- 1.40) microg/L (P < 0.05) respectively; but no difference in the serum level of TNF between MDS and control groups. The ratio of CD4+ to CD8+ in high clonal burden patients was 1.90 + 0.52, and in low clonal burden patients was 0.97 +/- 0.44 (P < 0.05).

CONCLUSIONThe clonal burden and deficient T cell immunity are the indicators for predicting MDS patients clinical progression.