Clinical significance of WHO classification and MDS 2000 classification in myelodysplastic syndromes

Excluding chronic myelomonocytic leukemia, a total of 92 consecutive patients with myelodysplastic syndrome showing less than 20% blasts in the bone marrow were analyzed. We evaluated the clinical significance of the WHO and MDS 2000 classifications by reviewing each MDS patient according to the classification. The WHO criteria classified the MDS patients into 36 with RA, 22 with RCMD and 33 with RAEB, whereas according to the MDS 2000 criteria there were 19 RAEB-I patients and 15 RAEB-II patients. Based on the WHO classification, the RCMD patients had higher platelet counts and percentages of blasts among BM cells than the RA patients (P = 0.0018, P = 0.0001). Twenty percent of the RA patients, 44.8% of the RCMD patients, and 70.8% of the RAEB patients had cytogenetic abnormalities. Among them, the poor karyotype was present in 6.7% of the RA patients, 21.0% of the RCMD patients and 41.6% of the RAEB patients. The rate of acute leukemia death was 14.3% in the RA patients, 67.7% in the RAEB patients and 50.0% in the RCMD patients. Analysis of survival times revealed significant differences between RA and RCMD patients (P = 0.0482). The clinical features of RCMD patients were intermediate between those of RAEB and RA patients. There was no difference between the clinical features of the RAEB-I and RAEB-II patients in the MDS 2000 classification.     

Hypocellular myelodysplastic syndromes (MDS): new proposals

Summary. To determine whether hypocellular MDS differs from normo/hypercellular MDS, we attempted to identify hypocellular MDS cases either by correcting the bone marrow (BM) cellularity by age (28 patients) or by using a single arbitrary value of BM cellularity (25 patients) and compared these two groups of hypocellular cases to the normo/hypercellular MDS cases (72 patients). 18 patients were common to both hypocellular groups. Patients with hypocellular MDS in both of these selected groups have similar features with regard to age and sex distribution, peripheral blood and bone marrow parameters, FAB subtypes, karyotypes, leukaemic transformation, and survival. However, the median age of patients in < 30% BM cellularity group was higher than those patients in the age-corrected group (69 years v 62 years). The selection of < 30% cellularity excluded 10 cases in the age group < 70 years but included another seven patients in the age group of > 70 years. However, correction of BM cellularity by age revealed that those included patients (selected for < 30% cellularity) who had normocellular BM by their age. Therefore we recommend the age-correcting grouping to ensure comparable series for comparison, for response to treatment, and survival. Finally, BM cellularity does not appear to be an important factor on prognosis in MDS, because patients with hypocellular MDS in both selected groups have similar prognosis to those with normo/hypercellular MDS patients.     

Cytogenetic studies in 69 patients with myelodysplastic syndromes (MDS)

Cytogenetic studies were performed in 69 patients with myelodysplastic syndromes classified according to the FAB proposals. Overall incidence of chromosomal anomalies was 48% with 5q-, +8, 12p-,-7/7q- being the aberrations most often found. The 12p- chromosome showed a close correlation with a prior exposure to mutagenic agents and CMML. Although there were no group-specific cytogenetic anomalies, FAB classification strongly influenced their incidence. They were lower (36%) in RA/RA-S than in RAEB/RAEB-T/CMML (53%). Chromosomal anomalies were significantly more often found in patients with a prior exposure to carcinogenic agents (80%) than in unexposed patients (33%). The presence of chromosomal anomalies did not predict a higher risk of leukemic transformation.     

骨髓增生异常综合征FAB和WHO分型的临床评价

目的:评价和分析骨髓增生异常综合征(MDS)从FAB分型到WHO分型的发展和临床意义。方法:对MDS患者分别用FAB分型及WHO分型进行分型,并对形态学、临床、实验室检查及预后资料进行对比分析。结果:MDS和急性髓性白血病(AML)均可出现病态造血。FAB分型中难治性贫血(RA)、原始细胞过多难治性贫血(RAEB)、转化中的原始细胞过多难治性贫血(RAEB-T)及AML之间生存率差异有统计学意义。WHO分型中RA与难治性血细胞减少伴多系增生异常(RCMD)之间生存率差异无统计学意义,RA与RAEB、RCMD与RAEB之间生存率差异有统计学意义,RAEB-Ⅰ与RAEB-Ⅱ之间生存率有显著差异。结论:WHO分型将FAB分型中的RA分为RA和RCMD并未显示出临床优越性。RAEB-T生存期比AML更短,因而将RAEB- T归为急性白血病,对临床治疗有好处。WHO分型按照原始细胞百分比将RAEB分为RAEB-Ⅰ和RAEB-Ⅱ,对临床诊断、治疗和预后有益。     

Azacitidine for treatment of patients with myelodysplastic syndromes (MDS): practical recommendations of the German MDS Study Group

Myelodysplastic syndromes (MDS) are a group of common bone marrow disorders characterized by ineffective hematopoiesis, peripheral cytopenias, and a substantial risk of progression to acute myeloid leukemia (AML). For many years, the main treatment option for MDS was best supportive care which alleviates symptoms, but has no effect on the natural course of the disease. Recently, demethylating agents have become available as a promising new treatment for patients with MDS. In two randomized clinical trials, the demethylating agent azacitidine has demonstrated a reduced risk of transformation to AML, improvement of peripheral blood values, an improved quality of life, and a definite survival advantage compared to conventional care regimens for patients with International Prognostic Scoring System score of intermediate-2 or high-risk MDS. This review aims to provide practical recommendations for the use of azacitidine and the management of its side effects in patients with MDS, assuring safe administration and best efficacy of treatment.     

骨髓增生异常综合征诊断与分型的新认识

骨髓增生异常综合征（ＭＤＳ）是全潜能干细胞水平上的分化障碍引起的一组克隆性恶性血液病。法美英（ＦＡＢ）三国协作组根据血象和骨髓象内的原始细胞数量、髓内环形铁粒幼细胞的多寡,以及周围血单核细胞的增多与否,将ＭＤＳ分为５种亚型（期）,即难治性贫血（Ｒ...     

Absence of MLL gene rearrangement in de novo myelodysplastic syndromes (MDS)

The Mixed Lineage Leukemia (MLL) gene has been identified in 11q23 translocations. The aim of the present study is the investigation of the frequency of MLL gene rearrangements in cases of de novo myelodysplastic syndromes (MDS). Sixty-two patients with de novo MDS were included in the analysis. The detection of MLL gene rearrangements was performed by Southern blot. Clonal karyotypic abnormalities were found in 15/50 (30%) cases. 11q23 abnormalities were not detected. One case with RAEB and a complex karyotype presented a del (11)(q13); further analysis by FISH revealed loss of one copy of MLL gene in all metaphases. Southern blot revealed germline bands in all cases using Eco RI and in 61/62 cases with Bam HI. The case with RAEB and a del (11)(q13) revealed a rearranged band following only Bam HI digestion, but not Eco RI. Rearrangements of MLL gene within exons 5–9 were not identified in this series of adult de novo MDS, indicating that this molecular abnormality is not involved in the pathogenesis of this group of hemopoietic disorders.