Abstract
We studied the effects of the presence of the HLA‐DR15 allele on the experimental and clinical features of myelodysplastic syndrome (MDS) by assessing the clinical data of 136 patients with MDS. We observed that the frequency of HLA‐DR15 expression in MDS patients (38.7%) was significantly higher than that in the healthy controls (p < 0.01). We noted the following observations with regard to disease progression: None of the 46 HLA‐DR15 positive patients with international prognostic scoring system (IPSS) scores ≤1 developed acute myeloid leukaemia (AML) during the follow‐up period, while six of the 63 DR15‐negative patients with the same IPSS score developed AML within a shorter follow‐up period (p = 0.039). Furthermore, the incidence of poor chromosomal abnormalities, the percentage of patients with IPSS scores ≥1.5 and the presence of ≥5% blasts in the bone marrow in the DR15‐positive patients were lower than the corresponding findings in the DR15‐negative patients. In addition, we also recorded the following observations with regard to bone marrow (BM) failure: The bicytopenia/pancytopenia ratio in the DR15‐positive patients was higher than that in the DR15‐negative patients (92.4 vs. 78.3%; p = 0.029). The peripheral–neutrophil count and the platelet count in the DR15‐positive patients were lower than those in the DR15‐negative patients (p = 0.028 and p = 0.011, respectively). Moreover, hypocellularity was more easily detectable in the DR15‐positive patients (26.4 vs. 16.9%). In addition, the BM CD4+ lymphocyte count and the CD4/CD8 ratio in the DR15‐positive patients were higher than the corresponding values in the DR15‐negative patients (p < 0.05 for both). However, there were no significant differences between the polarization of T‐helper (T~h~) and T‐cytotoxic (T~c~) cells and the cytokine levels in these two patient groups. We concluded that the presence of the HLA‐DR15 allele is indicative of a genetic susceptibility to MDS and, the presence of the HLA‐DR15 allele showed less association with disease progression and greater association with BM failure. Copyright © 2009 John Wiley & Sons, Ltd.