Tiejun Qin

Calreticulin mutations in Chinese with primary myelofibrosis

We tested 357 Chinese with primary myelofibrosis for mutations in CALR, JAK2 and MPL. CALR mutations were detected in 76 subjects (21%). There were 24 (32%) type-1 (L367fs*46) and 49 (64%) type-2 (K385fs*47) mutations. Seventy-two of 168 subjects (43%) without a JAK2 or MPL mutation had a CALR mutation. Subjects with a type-2 CALR mutation had lower hemoglobin concentrations (P=0.001), lower WBC counts (P<0.001), a higher percentage of blood blasts (P=0.009), and higher conventional (P<0.001) and Chinese-adjusted Dynamic International Prognostic Scoring System (P<0.001) scores compared with subjects with JAK2 mutations. Subjects with a type-2 CALR mutation were also likely to have abnormal platelet levels (<100 × 109/L, P=0.01 or >450 × 109/L, P=0.042) and no splenomegaly (P=0.004). Type-2 CALR mutation or no detectable mutation was an independent high-risk factor for survival in multivariate analyses. These data suggest the ratio between type-1 and type-2 mutations is reversed in Chinese with primary myelofibrosis compared with populations of subjects with primary myelofibrosis of predominately European descent. The unfavorable prognostic impact of CALR mutations in Chinese with primary myelofibrosis is only seen in those with type-2 mutations. These data underscore the need to evaluate the prognostic impact of genetic mutations in different populations.

TET2, ASXL1 and EZH2 mutations in Chinese with myelodysplastic syndromes

Somatic mutations of epigenetic gene regulators are common in patients with myelodysplastic syndromes (MDS) and correlate with some clinical and laboratory features. We studied mutations in TET2, ASXL1 and EZH2 in 153 Chinese patients with MDS. TET2 mutations were detected in 35 patients (23%), ASXL1 in 33 patients (22%) and EZH2 in 8 (5%). ASXL1 mutations were associated with increased colony formation of BFU-E, CFU-E and CFU-GM (P-values, 0.049, 0.011 and 0.006). EZH2 mutations were common in patients with poor IPSS cytogenetics (P=0.001) and in patients in the IPSS intermediate-2/high-risk cohorts (P=0.06). In uni- but not multi-variate analyses, mutated TET2 was associated with longer survival (P=0.044) whereas EZH2 mutations were associated with an increased risk of transformation to acute myeloid leukemia (AML; P=0.039). These data suggest ASXL1 mutations might results in dominance of the mutant clone in Chinese with MDS whereas EZH2 mutations might predict an increased risk of transformation to AML.

Unique cytogenetic features of primary myelodysplastic syndromes in Chinese patients.

Myelodysplastic syndromes (MDS) are a heterogeneous group of myeloid neoplasms. Chromosomal abnormalities have been detected in 40-70% patients with primary MDS and are heterogeneous among patients of different races and from different backgrounds. In the current study, 351 Chinese adult patients with primary MDS were retrospectively analyzed for their chromosomal abnormalities by karyotyping. Among the 237 cases (67.5%) of chromosomal abnormalities, 99 were copy number changes alone (41.7%), 70 were structural abnormalities alone (29.5%), and 68 displayed both of these changes (28.8%). Overall, the frequency of -5/5q-/del(5)(q13-33) was 5.1% in these Chinese MDS patients, which was lower than that in the MDS patients of western countries (8.7-23.4%), and the incidence of 5q- syndrome was only 0.3% in Chinese MDS patients. On the other hand, the frequencies of trisomy 8 (19.1%) and -20/20q-/del(20)(q11-13) (9.4%) were higher than those in western countries (1.2-7.0% and 2.0-3.5%, respectively). Chromosomal translocations were also detected in 31 cases (13.1%) including 12 rare translocations that have not been reported in MDS patients before. In addition, i(17)(q10) was detected in nine cases (3.8%), of which six cases only had this single abnormality. According to the IPSS chromosomal prognostic classification, the incidence of poor-risk karyotypes increased in the advanced WHO subtypes (p < 0.001). Together, we detected the unique cytogenetic features of chromosomal abnormalities and some rare translocations of MDS among Chinese patients.

Unique features of primary myelofibrosis in Chinese

Clinical and laboratory features of 642 consecutive Chinese subjects with primary myelofibrosis (PMF) were analyzed and compared with those of 1054 predominately white subjects with PMF. Chinese subjects were significantly younger, fewer had constitutional symptoms, and fewer had a palpable spleen or liver. Anemia, in contrast, was significantly more common in Chinese as was an increased white blood cell count and low platelet count. The reason for these differences is unclear, but it does not seem to be correlated with delayed diagnosis. A small but significantly increased proportion of Chinese had the JAK2(V617F) mutation but no difference in the frequency of haplotypes associated with PMF in whites. Survival of Chinese with PMF was also significantly longer than that of whites with PMF. We found commonly used staging systems for PMF such as the International Prognostic Scoring System and the Dynamic International Prognostic Scoring System were suboptimal predictors of survival in Chinese with PMF, and we developed a revised prognostic score that should help in comparison of data between studies of PMF in different populations and planning of clinical trials.

CSF3R, SETBP1 and CALR mutations in chronic neutrophilic leukemia

The WHO 2008 definition of chronic neutrophilic leukemia (CNL) is based on clinical and laboratory parameters but not on molecular abnormalities. Mutations in CSF3R, SETBP1 and CALR are reported in patients with chronic neutrophilic leukemia (CNL). However, because CNL is rare, there are few large studies of this issue. We sequenced these genes in 14 patients who met the WHO-criteria of CNL. 8 subjects had CSF3RT618I, 6 SETBP1 mutations and 1 a CALR mutation. Our data suggest mutation analysis of CSF3R, SETBP1 and CALR should be included in the diagnostic criteria for CNL. These data may also have therapy implications.

Serum iron metabolism and erythropoiesis in patients with myelodysplastic syndrome not receiving RBC transfusions

Dysregulation of hepcidin, a key iron regulating hormone, is important in the pathogenesis of iron overload in patients with myelodysplatic syndrome (MDS). However, most studies of hepcidin levels are complicated by concomitant RBC transfusions. To evaluate the relationship between iron metabolism and erythropoiesis, we measured serum levels of hepcidin, growth-differentiation factor-15 (GDF15) and other markers of erythropoiesis in 107 subjects with MDS not receiving RBC transfusions. Patients with MDS had significantly higher levels of hepcidin than normals. However, their hepcidin-ferritin ratio was markedly decreased compared to normals (P<0.001) and varied substantially between MDS subtypes (P=0.011). GDF15 levels positively correlated with percent of bone marrow erythroblasts (P<0.001), soluble transferrin receptor (sTfR) (P=0.018), and also with transferrin saturation (ISAT) (P=0.038). The hepcidin-ferritin ratio negatively correlated with serum erythropoietin (EPO) levels (P<0.001), and also with GDF15 levels (P=0.014). Colony forming cells (CFC) were evaluated in 70 subjects. Those with serum ferritin (SF) levels <500 ng/ml had significantly more BFU-E than subjects with SF ≥ 500 ng/L (P=0.007), but numbers of granulocyte/macrophage-colony-forming cells (CFU-GM) were similar (P=0.190). Our data indicate serum hepcidin levels are inappropriately low in patients MDS not receiving RBC transfusions. GDF15 levels correlated with low hepcidin levels and may contribute to iron overload in this setting. Iron overload may in turn suppress erythropoiesis by imparing the proliferative capacity of the erythroid progenitor cells.

Clinical importance of SF3B1 mutations in Chinese with myelodysplastic syndromes with ring sideroblasts

Recent studies report SF3B1 mutations in about 20% of persons of European descent with myelodysplastic syndromes (MDS). Mutations are especially common in persons with ring sideroblasts (RS). SF3B1 mutation state was determined in 104 Chinese with MDS-RS. SF3B1 mutations were found in 55 subjects (53%) including 25 of 39 with refractory anemia and RS (RARS), 26 of 45 (58%) of those with refractory cytopenia with multi-lineage dysplasia and RS (RCMD-RS), 3 of 6 with refractory anemia with excess blasts-1-RS (RAEB1-RS) and 1 of 14 with RAEB2-RS. There were significant correlations between SF3B1 mutation state and platelet levels (P=0.007), mean RBC corpuscular volume (MCV; (P<0.001), proportion of RS (P<0.001) and percent bone marrow erythroblasts (P=0.012) and myeloblasts (P=0.044). Multivariate analyses using a Cox proportional hazards regression model including sex, age, SF3B1 mutation state, hemoglobin concentration, absolute neutrophil level, platelet level, MCV, international prognostic scoring system (IPSS) cytogenetics category, WHO morphologic category and treatment showed SF3B1 mutation state to independently predict survival. These data increase our knowledge of the impact of SF3B1 mutations in persons with MDS. They indicate a similar favorable impact of SF3B1 mutation on survival in Chinese with MDS as reported for persons of European descent.

RAD51 and XRCC3 polymorphisms: impact on the risk and treatment outcomes of de novo inv(16) or t(16;16)/CBFβ-MYH11(+) acute myeloid leukemia.

DNA double-strand break repair via homologous recombination (HR) is essential in maintaining genetic integrity, and may modulate susceptibility to the development of acute myeloid leukemia (AML) and influence outcomes of AML. This study was designed to evaluate the effects of polymorphisms in HR repair genes RAD51 and XRCC3 on the risk and treatment outcomes of inv(16)/t(16;16)/CBFβ-MYH11(+) AML. The distribution of polymorphisms in RAD51-G135C and XRCC3-Thr241Met were studied by PCR-RFLP analysis in 625 cases of de novo AML, including 105 cases with inv(16)/t(16;16)/CBFβ-MYH11, 806 family controls and 704 volunteer controls. It was found that the XRCC3-241Met variant significantly increased the risk of the development of the AML with inv(16)/t(16;16) as compared with both the volunteer control (OR=7.22; 95% CI, 4.37-11.91) and the family control (OR=7.99; 95% CI, 5.03-12.69). A retrospective study conducted in 103 inv(16)/t(16;16) AML patients. In multivariate analysis for the potential prognostic factors, the XRCC3-241Met variant significantly reduced disease-free survival (DFS) in complete remission (CR) achieved patients (HR=2.34, 95% CI, 1.32-4.16). These data indicate that the XRCC3-241Met variant may not be only a susceptibility factor to the AML with inv(16)/t(16;16), but also an independent poor-prognostic factor for this AML subtype.

Periodic oscillation of blood leukocytes, platelets, and hemoglobin in a patient with chronic eosinophilic leukemia

Chronic eosinophilic leukemia (CEL) is a rare myeloproliferative disease in which autonomous, clonal proliferation of eosinophilic precursors results in persistent increase of eosinophils in the blood and bone marrow. A case of CEL spontaneous oscillation of white blood cell (WBC) count is presented. The cycle of WBC variation comprised about 60 days. Similar cyclic variations were noted in his platelet count, hemoglobin level and bone marrow cellularity, as well as in the spleen size, which was directly correlated with the WBC count. The numbers of bone marrow erythroid colony-forming units (CFU-E), granulocyte-macrophage colony-forming units (CFU-GM) and the serum level of colony-stimulating factors (CSFs) were also regularly changed during the oscillation of WBC. Bone marrow hyperplasia was accompanied with the increase in peripheral WBC count, suggesting that the variation of cell production caused the cyclic oscillation.

Impacts of cytogenetic categories in the Revised International Prognostic Scoring System on the prognosis of primary myelodysplastic syndromes: results of a single-center study

Abstract Recently, the Revised International Prognostic Scoring System (IPSS-R) has been developed for assessing the prognosis of primary myelodysplastic syndromes (MDS) and has shown satisfactory outcomes for prognostic stratification. In this new system, cytogenetics remains the key stratification parameter and karyotypic abnormalities are classified into five prognostic subgroups with more uncommon cytogenetic subsets. Using this system, we analyzed the cytogenetic features of 532 adult Chinese patients with primary MDS and assessed the impacts of the IPSS-R cytogenetic categories on the prognosis of the disease without intensive treatment. Here, we show that the cytogenetic features of this cohort of Chinese patients are different from those of previously reported Western populations with MDS. In our Chinese patients, trisomy 8 was the most common anomaly, and the incidence rate of del(5q) was lower than that in the Western population. In the IPSS-R cytogenetic subgroups, the median survival was 59 months for the good risk, 36 months for the intermediate risk, 15 months for the poor risk and 10 months for the very poor risk subgroups (p < 0.001). In conclusion, the IPSS-R can effectively stratify the prognosis of MDS based on cytogenetics, but the prognostic significances of some karyotypes in the IPSS-R still need to be confirmed by larger multicenter cooperative studies.