[Clinical significance of cytogenetic monitoring in chronic myeloid leukemia]

Objective: To analyze the association of cytogenetic abnormalities with the prognosis of chronic myeloid leukemia (CML) patients in tyrosine kinase inhibitors (TKI) era. Methods: Karyotype analysis of chromosome G-banding was carried out in 387 newly diagnosed CML patients by short-term culture of bone marrow cells. The correlation of cytogenetic abnormalities and CML progression was explored in combination with ABL tyrosine point mutations. Result: Of 387 patients with positive BCR-ABL fusion gene assayed by fluorescence in situ hybridization (FISH) technique, 94.1% (364/387) patients were Ph positive and 5.9% (23/387) Ph negative; 320 patients (87.9%) had a translocation t (9;22) (q34;q11) and 5 (1.4%) a variant translocation t (v;22) . Additional cytogenetic aberrations (ACA) at diagnosis were found in 10.7% (39/387) Ph(+) patients, major route ACA in 22 (56.4%) cases and minor route ACA in 15 (38.5%) cases and 2 patients (5.1%) lacked the Y chromosome (-Y) ; 23.4% (71/303) patients occurred ACA during TKI treatment and the most frequent abnormalities were abnormal chromosome numbersd, which were likely associated with high proportion of disease progression (χ(2)=168.21, P<0.001) and ABL tyrosine point mutations (χ(2)=29.04, P<0.001) . Newly diagnosed CML-CP patients with t (9;22) (q34;q11) had a longer event-free survival (EFS) and disease-free survival (DFS) rates than that of patients with ACA (P=0.037; P=0.003) , while the overall survival (OS) had no significant differences (P=0.209) . As for CML-CP patients that occurred ACA during TKI therapy would have a marked low OS, EFS and DFS (all P<0.001) compared with no ACA occurred patients. Survival of advanced patients that occurred ACA were dramatically reduced. Conclusion: ACA often emerged during the disease progress in CML patients, regular and timely detection of chromosomes karyotype and ABL tyrosine point mutations during TKI treatment was important for therapeutic evaluation, progress and prognosis of CML.

The epigenetically-regulated miR-34a targeting c-SRC suppresses RAF/MEK/ERK signaling pathway in K-562 cells

Previous reports show that miR-34a suppressed K-562 cell proliferation and contributed to megakaryocytic differentiation of K-562 cells. Here, we reported that miR-34a, a tumor suppressor gene, is down-regulated in the K-562 cells and chronic myeloid leukemia (CML) patients due to aberrant DNA hypermethylation. c-SRC is a target of miR-34a. Restoring miR-34a expression resulted in down-regulation of c-SRC and phosphorylated (Tyr416) c-SRC protein in K-562 cells, which consequently triggered suppression of the RAF/MEK/ERK signaling pathway to decrease cell proliferation.

[Pharmacokinetics of generic dasatinib in the management of chronic myeloid leukemia in the choronie phase]

Objective: To evaluate the pharmacokinetics and bioequivalence of generic dasatinib in patients with chronic myeloid leukemia in the choronie phase (CML-CP). Methods: Using randomized, parallel, overlapping, self-control designed study, a 100 mg dose of the reference or test tablet was given to 12 CML-CP patients who were resistant or intolerant to Imatinib and Nilotinib in a randomized two-way crossover design, and the plasma concentration of the medicine was assayed by HPLC-MS-MS. The main pharmacokinetic parameters and bioequivalence of the two formulations were evaluated. Results: The major pharmacokinetic parameters were as follows: Cmax (209.01±58.69) μg/L and (223.07±79.51) μg/L, Tmax (1.1±0.8) h and (1.1±0.8) h, T1/2 (5.10±1.34) h and (4.39±0.74) h, AUC0-τ (646.65±185.67) h·μg/L and (695.84±273.40) h·μg/L (all P>0.05); AUC0-∝ (668.11±186.00) h·μg/L and (712.42±278.08) h·μg/L, MRT (5.32 ± 1.70) h and (4.68 ± 1.53) h (all P>0.05). Conclusion: The two formulations were bioequivalent.

Development of a protease-resistant reporter to quantify BCR-ABL activity in intact cells

A peptidase-resistant ABL kinase substrate was developed by identifying protease-susceptible bonds on an ABL substrate peptide and replacing flanking amino acids with non-native amino acids. After an iterative design process, the lead, or designed, peptide X-A possesses a six-fold longer life in a cytosolic lysate than that of the starting peptide. The catalytic efficiency (kcat/KM) of purified ABL kinase for the lead peptide (125 s-1 μM-1) is similar to that of the starting peptide (103 s-1 μM-1) demonstrating preservation of the peptide's ability to serve as a kinase substrate. When incubated in cytosolic lysates, the lead peptide is slowly degraded into 4 fragments over time. In contrast, when loaded into intact cells, the peptide is metabolized into 5 fragments, with only 2 of the fragments corresponding to those in the lysate. Thus the two environments possess differing peptidase activities, which must be accounted for when designing peptidase-resistant peptides. In both settings, the substrate is phosphorylated by BCR-ABL providing a readout of BCR-ABL activity. A small panel of tyrosine kinase inhibitors verified the substrate's specificity for BCR-ABL/ABL kinase activity in both lysates and cells in spite of the multitude of other kinases present. The designed peptide X-A acts as a long-lived BCR-ABL kinase reporter in the leukemic cells possessing the BCR-ABL mutation.

[Comparative Analysis of Efficacy and Drug Resistance of Imatinib in Patients with Chronic Myeloid Leukemia at Chronic and Advanced Phases]

OBJECTIVE

To compare the efficacy and drug resistance of imatinib in patients with chronic myeloid leukemia (CML) at chronic phase (CP) and advanced phase (accelerated phase and blast crisis (AP+BC).

METHODS

Forty-two patients with CML were treated with imatinib of different doses(CP 400 mg/d, AP+BC 600 mg/d), and the efficacy and drug resistance of the 2 groups were compared. The median follow-up time was 24 months (3-42 months).

RESULTS

The complete hematological remission rate (CHR), the major cytogenetic remission rate (MCyR) and complete molecular remission rate (CMoR) in the CP group were 100%, 89.6% and 20.1% respectively, while those in advanced phase group were 46.2%, 308% and 0; survival rate of 42 months in CP patients was 76.7%, and that in advanced phase group was 39.2%, the difference between them was statistically significant (P<0.05). The incidence of severe hematologic adverse reaction in advanced phase group was higher than that in CP Group; among 42 cases of CML, the drug-resistance happened in 13 cases, out of them 9 cases was CML in advanced phase; the drug resistance rate in CML in advanced phase group (69.2%) was significantly higher than that in CML-CP group(13.8%). The correlation factor analysis showed that the effects of the advanced phase and the lower dose of the drug were statistically significant.

CONCLUSION

Imatinib can provide certain curative effect for CML patients at different phases, especially for the patients at chronic phase; the early MCyR for patients with CML is an important factor in long-term survival; drug resistance is an important factor affecting the efficacy of imatinib; The incidence of imatinib drug resistance at the late stage has been found to be higher.

[Efficacy of three prognostic scoring systems on evaluating the prognosis for patients with chronic myeloid leukemia]

OBJECTIVE

To retrospectively analyze the efficacy of three prognostic scoring systems on evaluating the prognosis for patients with chronic myeloid leukemia (CML) in chronic phase (CP).


METHODS

In this retrospective cohort study, we collected 234 patients with CML in CP, who were treated with imatinib mesylate (IM). Patients were stratified into low-, intermediate- and high- risk groups according to three scoring systems (Sokal, Hasford and EUTOS), respectively. We compared the agreement of overall survival (OS), progression free survival (PFS), event free survival (EFS) in CML patients stratified by three prognostic scoring systems. The median for follow-up was 20.5 months. 


RESULTS

EUTOS scoring system: In the low- and high-risk groups, the 5-year OS was 94.6% and 84.7% (P=0.011), 5-year EFS was 92.6% and 77.6% (P=0.001), and 5-year PFS was 95.3% and 82.4% (P=0.001), respectively. While stratified by Sokal or Hasford scoring system, there was no significant the correlation between low-, intermediate- and high- risk groups with the prognosis for CML patients (P>0.05). Compared with Sokal and Hasford scoring system, the outcome of EUTOS prognostic scoring system showed highly accordance with 5-year expect OS, PFS and EFS of CML patients.


CONCLUSION

EUTOS scoring system could predict the long-time outcome of CML-CP patients better than Sokal and Hasford scoring system. Chang of treatment may affect the prognostic value of EUTOS scoring system.

Coexistent chronic myelogenous leukemia with squamous cell carcinoma of the larynx associated with NOD2/CARD15 mutation in a young adult

We report the case of a 37-year-old man with human papillomavirus-positive squamous cell carcinoma of the larynx coexisting with chronic myelogenous leukemia. The patient had no history of smoking or alcohol consumption. Within a few months, his rapidly growing tumor was classified as T4aN2cM0. It could be assumed that the rapid increase in the tumor mass, which did not respond positively to treatment, might have been associated with the coexistence of the chronic myelogenous leukemia, which had been found incidentally. Genetic testing revealed the presence of insertion mutation 3020insC within the NOD2 gene, which might be an important genetic predisposing factor, not only for a single tumor such as laryngeal cancer, but also for multiple primary neoplasms. The presence of an NOD2 mutation could significantly worsen the course of the cancer. Therefore, given the relatively high frequency of 3020insC mutations in the general population, it might be reasonable to perform genetic testing on a wider scale for patients with head or neck cancer, particularly in cases that follow an atypical course. It is also worth emphasizing the importance of thorough and periodically repeated laryngeal examinations in patients with chronic leukemia.

Biodegradable charged polyester-based vectors (BCPVs) as an efficient non-viral transfection nanoagent for gene knockdown of the BCR-ABL hybrid oncogene in a human chronic myeloid leukemia cell line

First-line therapy of chronic myelogenous leukemia (CML) has always involved the use of BCR-ABL tyrosine-kinase inhibitors which is associated with an abnormal chromosome called Philadelphia chromosome. Although the overall survival rate has been improved by the current therapeutic regime, the presence of resistance has resulted in limited efficacy. In this study, an RNA interference (RNAi)-based therapeutic regime is proposed with the aim to knockdown the BCR-ABL hybrid oncogene using small interfering RNA (siRNA). The siRNA transfection rates have usually been limited due to the declining contact probability among polyplexes and the non-adherent nature of leukemic cells. Our work aims at addressing this limitation by using a biodegradable charged polyester-based vector (BCPV) as a nanocarrier for the delivery of BCR-ABL-specific siRNA to the suspension culture of a K562 CML cell line. BCR-ABL siRNAs were encapsulated in the BCPVs by electrostatic force. Cell internalization was facilitated by the BCPV and assessed by confocal microscopy and flow cytometry. The regulation of the BCR-ABL level in K562 cells as a result of RNAi was analyzed by real-time polymerase chain reaction (RT-PCR). We observed that BCPV was able to form stable nanoplexes with siRNA molecules, even in the presence of fetal bovine serum (FBS), and successfully assisted in vitro siRNA transfection in the non-adherent K562 cells. As a consequence of downregulation of BCR-ABL, BCPV-siRNA nanoplexes inhibited cell proliferation and promoted cell apoptosis. All results were compared with a commercial transfection reagent, Lipofectamine2000™, which served as a positive control. More importantly, this class of non-viral vector exhibits biodegradable features and negligible cytotoxicity, thus providing a versatile platform to deliver siRNA to non-adherent leukemia cells with high transfection efficiency by effectively overcoming extra- and intra-cellular barriers. Due to the excellent in vitro transfection results from BCPV-siRNA, a newly developed biodegradable transfection agent, BCPV, is being probed for transfection performance in an animal model.

[Expression and Clinical Significance of DNMT in Patients with Chronic Myeloid Leukemia]

OBJECTIVE

To investigate the expression and clinical significance of DNA methyltransferases (DNMT) mRNA in patients with chronic myeloid leukemia (CML).

METHODS

The expression levels of DNMT mRNA in mononucllear cells (MNC) of bone marrow or in peripheral blood of 93 CML patients in 3 different phases and 10 normal controls (NC) were detected by SYBR Green flurescent quatitative PCR.

RESULTS

The relative expression levels of DNMT1 mRNA in NC, chronic phase CML (CML-CP), accelerated phase (CML-AP) and blastic phase (CML-BP) were 1.45 ± 0.22, 1.83 ± 0.63, 2.95 ± 0.87 and 3.24 ± 1.39 resectively. The expression of DNMT1 mRNA showed no statistically significant difference between CML-CP and NC (P = 0.28). The expression of DNMT1 mRNA in advanced stages (including CML-AP and CML-BP) of CML obviously increased in comparison with CML-CP and NC (P < 0.05). The expression of DNMT1 mRNA in CML-AP was not significantly different from that in CML-BP (P = 0.336). The relative expression levels of DNMT3a mRNA in NC, CML-CP, CML-AP and CML-BP groups were 1.29 ± 0.34, 1.34 ± 0.46, 2.33 ± 1.05 and 3.18 ± 1.23 resectively. And the expression levels of DNMT3a mRNA were not statistically significantly different between CML-CP and NC (P = 0.844). The results showed that the expression of DNMT3a mRNA in the advanced phase of CML significantly increased in comparison with that in CML-CP and NC (P < 0.05). Meanwhile, the expression of DNMT3a mRNA in CML-AP was not different from that in CML-BP (P = 0.304). The relative expression levels of DNMT3b mRNA in NC, CML-CP, CML-AP and CML-BP groups were 1.37 ± 0.31, 16.41 ± 22.50, 9.36 ± 5.50 and 12.17 ± 13.44 resectively. It was also found that the level of DNMT3b mRNA in CML significantly increased in comparison with NC (P < 0.05), and that the between the 3 different phase of CML was not statistically significantly different (P >0.05).

CONCLUSION

The expression of DNMT mRNA increases in advanced CML as compared with normal controls and CML-CP, and the increased levels of DNMT mRNA probably correlate with disease progression in CML.

Towards a Molecular Understanding of the Link between Imatinib Resistance and Kinase Conformational Dynamics

Due to its inhibition of the Abl kinase domain in the BCR-ABL fusion protein, imatinib is strikingly effective in the initial stage of chronic myeloid leukemia with more than 90% of the patients showing complete remission. However, as in the case of most targeted anti-cancer therapies, the emergence of drug resistance is a serious concern. Several drug-resistant mutations affecting the catalytic domain of Abl and other tyrosine kinases are now known. But, despite their importance and the adverse effect that they have on the prognosis of the cancer patients harboring them, the molecular mechanism of these mutations is still debated. Here by using long molecular dynamics simulations and large-scale free energy calculations complemented by in vitro mutagenesis and microcalorimetry experiments, we model the effect of several widespread drug-resistant mutations of Abl. By comparing the conformational free energy landscape of the mutants with those of the wild-type tyrosine kinases we clarify their mode of action. It involves significant and complex changes in the inactive-to-active dynamics and entropy/enthalpy balance of two functional elements: the activation-loop and the conserved DFG motif. What is more the T315I gatekeeper mutant has a significant impact on the binding mechanism itself and on the binding kinetics.

[A multicenter comparison study on the detection of BCR-ABL tyrosine kinase domain point mutation]

OBJECTIVE

To investigate the accuracy and consistency of the detection of BCR-ABL tyrosine kinase domain point mutation among different laboratories.

METHODS

Every one of 6 laboratories prepared 10 cDNA samples from tyrosine kinase inhibitors resistant BCR-ABL (P210 or P190) positive patients'bone marrow or peripheral blood. Each cDNA sample was divided into 6 aliquots and delivered to the laboratories. All 6 laboratories tested BCR-ABL point mutations of 60 samples according to their own protocols. Peking University People's Hospital analyzed the comparison results based on both the reports and sequencing chromatogram from all laboratories.

RESULTS

All laboratories reported the same nucleotide and corresponding amino acid mutations in 37 samples (61.7%）. Of 60 samples, 53 had confirmed mutation types, and a total of 23 types were included; 1 had no mutation; mutation types of 6 samples could not be determined because of the big differences among chromatograms from different laboratories. Low percentages of mutants were significantly related to results inconsistency (P=0.008). Inconsistent result of one sample was caused by the unique chromatogram of the mutant L248V, and one by the non-coverage amplification of PCR product from different laboratories. Amplification was failed in 3 samples. Testing or sequencing mistakes occurred in 7 samples. The differences in the mutant percentages among laboratories were less than 20% in the 80.6% of samples with confirmed results. Low internal control gene copies (ABL<10 000) were significantly related to both failed amplification and big differences among chromatograms from different laboratories (P=0.005 and <0.001, respectively).

CONCLUSION

Problems in the clinical routine detection of BCR-ABL point mutation could be exposed and improvement could be achieved by sample exchange and comparison. Low percentage of mutant is the main reason which causes the discrepancy of BCR-ABL point mutation results among different laboratories.

[A prospective, multi-centre clinical trial to evaluate the early clinical efficacy and safety of a generic imatinib in treating patients with chronic phase of chronic myelogenous leukemia]

OBJECTIVE

To evaluate the early hematologic, cytogenetic and molecular responses in newly diagnosed patients with chronic myelogenous leukemia in chronic phase（CML-CP）and initially treated with a generic imatinib（Xinwei）, manufactured by Jiansu Hansoh Pharmaceutical Group Co., Ltd.

METHODS

107 newly diagnosed patients of CML-CP, whose ages were above 18- year- old and who had never received any tyrosine kinase inhibitor（TKI）were treated with Xinwei 400 mg QD. The hematologic, cytogenetic and molecular responses were assessed at 3- and 6-month, and adverse effects were evaluated throughout the study.

RESULTS

107 patients were treated with Xinwei for at least 3 months, 54 of them were treated for 6 months or more. At 3- month, the complete hematologic responses（CHR）rate were 98.1%（105/107）; 47/57（82.5%） patients achieved major cytogenetic response（MCyR）, and 20/57 （35.1%） patients complete cytogenetic response（CCyR）; BCR- ABLIS was ≤10% in 77/106 patients （72.6%）, 11 of them（10.4%）achieved major molecular response（MMR, BCR-ABLIS was ≤0.1%）. At 6-month, the CHR rate was 100%（54/54）; 28/39 patients（71.8%）achieved CCyR; BCR-ABLIS was ≤1% in 37/54 patients （68.5% ）, 18 of them （33.3% ） achieved MMR. The grade Ⅲ leukopenia, thrombocytopenia and anemia rates were 19.5%, 23.0% and 13.8%, respectively. No grade Ⅳ hematologic toxicity occurred. The common non- hematologic toxicities were edema（74.7%）, nausea（48.3%）, bone pain（42.5%）, rash（36.8%）, diarrhea（34.5%）, fever（23.0%）, cramp（11.5%）and impaired liver function （3.4%）. No patient experienced grade Ⅳ non- hematologic toxicity. No adverse effects related death occurred.

CONCLUSION

Our results revealed the excellent early haematology, cytogenetic and molecular responses and safety of Xinwei in treating patients with CML-CP.

[Clinical Efficacy of Dasatinib, Nilotinib and Imatinib in Newly Diagnosed Patients with Chronic-Phase Chronic Myeloid Leukemia: A Three-year Retrospective Analysis]

OBJECTIVE

To evaluate efficacy and safety of second-generation tyrosine kinase inhibitors (TKI) dasatinib, nilotinib and imatinib in treatment of newly diagnosed patients with chronic-phase chronic myeloid leukemia (CML).

METHODS

The clinical data and follow-up results of 163 patients with chronic-phase chronic myeloid lenkemia(CP-CML) who were treated in our hospital during the nearly 3 years were analysed retrospectively, among 163 patients 47 received dasatinib, 43 received nilotinib and 73 received imatinib. The efficacy, disease progression and safety were evaluated.

RESULTS

After treatment for 3 months, the rate of complete hematologic response(CHR) in three treatment groups were 77%, 79% and 67%, respectivily, CHR at 12 months in three treatment groups were 92%, 91% and 90%, respectively. By 3 months, the rates of complete cytogenetic response(CCyR) with dasatinib and nilotinib were higher than that with imatinib (55%, 53% vs 33%)(P<0.05 for both comparisons), CCyR at 12 months in three treatment groups were 86%, 88% vs 69% (P<0.05 for both comparisons). The rates of major molecular response(MMR) for dasatinib (11%) and nilotinib (9%) by 3 months were significantly higher than that for imatinib (1%) (P<0.05 for both comparisons), MMR at 12 months in three treatment groups were 49%, 50% and 28%, respectively (P<0.05 for both comparison). Progression to the accelerated or blast phase of CML occurred in 2 (4%) patients received dasatinib, 2 (5%) received nilotinib and 6 (8%) received imatinib. The safety profiles of these 3 second-generation TKI treatments were similar.

CONCLUSION

Both dasatinib and nilotinib induced strikingly higher and faster rates of complete cytogenetic response and major molecular response, with a statistically significant difference from imatinib.

[Generation and identification of P210(T315I-BCR/ABL) transgenic mice]

OBJECTIVE

To construct the P210(T315I-BCR/ABL) transgenic mice model.

METHODS

The transgenic vector in which the P210(T315I-BCR/ABL) gene and eGFP gene was derived by APN/CD13 promoter was constructed and microinjected into the single-cell fertilized eggs of C57 mice. Transgene integration was conformed by PCR genotyping and P210(T315I-BCR/ABL) expression levels was evaluated by RT-PCR. The CML phenotype was confirmed by blood routine examination, Wright's staining for peripheral blood and bone marrow smears, HE staining for organs of transgenic mice.

RESULTS

Three transgenic mice lines with high expression of P210(T315I-BCR/ABL) gene and eGFP gene was selected. Compared with the wild type mice, the levels of WBC, platelet and neutrophil granulocyte of transgenic mice began to increase gradually at 2 months, and increase to 23.9×10⁹/L, 4 136×10⁹/L, and 74.6% respectively at 6 months. The remarkable hyperplasia of granulocytes was seen in the peripheral blood and bone marrow smears with splenomegaly infiltrated by leukemic cells.

CONCLUSION

The P210(T315I-BCR/ABL) transgenic mice was constructed and provided a model to explore the mechanism of T315I CML and screen out the drug for T315 CML patient.

Biomarkers for personalized oncology: recent advances and future challenges

Cancer is a group of diseases characterized by the uncontrolled growth and spread of abnormal cells and oncology is a branch of medicine that deals with tumors. The last decade has seen significant advances in the development of biomarkers in oncology that play a critical role in understanding molecular and cellular mechanisms which drive tumor initiation, maintenance and progression. Clinical molecular diagnostics and biomarker discoveries in oncology are advancing rapidly as we begin to understand the complex mechanisms that transform a normal cell into an abnormal one. These discoveries have fueled the development of novel drug targets and new treatment strategies. The standard of care for patients with advanced-stage cancers has shifted away from an empirical treatment strategy based on the clinical-pathological profile to one where a biomarker driven treatment algorithm based on the molecular profile of the tumor is used. Recent advances in multiplex genotyping technologies and high-throughput genomic profiling by next-generation sequencing make possible the rapid and comprehensive analysis of the cancer genome of individual patients even from very little tumor biopsy material. Predictive (diagnostic) biomarkers are helpful in matching targeted therapies with patients and in preventing toxicity of standard (systemic) therapies. Prognostic biomarkers identify somatic germ line mutations, changes in DNA methylation, elevated levels of microRNA (miRNA) and circulating tumor cells (CTC) in blood. Predictive biomarkers using molecular diagnostics are currently in use in clinical practice of personalized oncotherapy for the treatment of five diseases: chronic myeloid leukemia, colon, breast, lung cancer and melanoma and these biomarkers are being used successfully to evaluate benefits that can be achieved through targeted therapy. Examples of these molecularly targeted biomarker therapies are: tyrosine kinase inhibitors in chronic myeloid leukemia and gastrointestinal tumors; anaplastic lymphoma kinase (ALK) inhibitors in lung cancer with EML4-ALk fusion; HER2/neu blockage in HER2/neu-positive breast cancer; and epidermal growth factor receptors (EGFR) inhibition in EGFR-mutated lung cancer. This review presents the current state of our knowledge of biomarkers in five selected cancers: chronic myeloid leukemia, colorectal cancer, breast cancer, non-small cell lung cancer and melanoma.

[Allo-geneic hematopoietic stem cell transplantation in treatment with T315I mutation of chronic myelogenous leukemia]

OBJECTIVE

To explore the therapeutic efficacy of allo-geneic hematopoietic stem cell transplantation (allo-HSCT) for chronic myelogenous leukemia (CML) patients with T315I mutation.

METHODS

Retrospective analyses were conducted for 4 patients with T315I mutation of CML undergoing allo-HSCT from June 2012 to January 2014, including 2 cases in acceleration phase and 2 in chronic phase. There were 2 males and 2 females with ages from 26 to 45 years. Two patients received HLA-matched sibling allo-geneic peripheral blood stem cell transplantation (allo-PBSCT) while another 2 unrelated cord blood stem cell transplantation (UCBT). No splenomegaly was found before transplantation. One case had F317L mutation. All of them were treated with imatinib before transplantation. And the time from medication to T315I mutation was 20-35 months. All of them were conditioned with myeloablative regimen and received a combination of cyclosporine A (CsA) and mycophenolate mofetil (MMF) for preventing graft-versus-host disease (GVHD).

RESULTS

Myeloid implantation was achieved in all of them. The time of absolute neutrophil count (ANC) ≥ 0.5×10(9)/L were 10-28 days. One patient whose platelet was not implanted died from severe pulmonary infection at Day 88 post-transplantation. For 3 patients, platelet ≥ 20×10(9)/L were 15-33 days. But the marrow short tandem repeat (STR)-PCR was 100% donor type at the time of 30 days post-transplantation in all patients. One case of UCBT developed pre-implantation immune response syndrome (PES) and one acute GVHD of gradeI at Day 12 after allo-PBSCT. However both were controlled after treatment with methylprednisolone. And 1/3 evaluatable patients developed chronic GVHD. BCR/ABL transcript was detected by qualitative PCR after transplantation. And all BCR/ABL fusion genes turned negative after 30 days of transplantation. Up to the follow-up endpoint, there was no relapse except for one mortality. And the time of disease-free survival was 133, 248 and 704 days respectively.

CONCLUSIONS

Allo-HSCT is currently the optimal treatment for T315I mutation of CML. And umbilical cord blood is an ideal donor for those patients without HLA-matched sibling donor.

[Increased risk of severe acute graft-versus-host disease in low body mass index patients undergoing haploidentical allogeneic stem cell transplantation]

OBJECTIVE

To investigate the impact of body mass index (BMI) before transplantation on clinical outcomes of haploidentical allogeneic stem cell transplantation (allo-HSCT).

METHODS

We performed a retrospective cohort study of 253 adult patients with acute or chronic leukemia who received haploidentical allo-HSCT from August 2008 to September 2011. All conditioning regimens were myeloablative and bulsufan based. Patients were stratified according to BMI values (low BMI group: <18 kg/m(2); normal BMI group: ≥ 18 and < 25 kg/m(2); overweight BMI group: ≥ 25 kg/m(2)). Other possible risk factors correlated with GVHD, relapse, transplant related mortality (TRM) and overall survival (OS) included age and gender of donor and recipient, HLA disparity, relationship between donor and recipient, diagnosis, status of disease, ATG dose in conditioning regime(10 mg/kg , 6 mg/kg), mononuclear cells (MNC), CD(+)34 and CD(+)3 cell amount from granulocyte colony-stimulating factor (G-CSF) primed bone marrow grafts (G-BM) and G-CSF mobilized peripheral blood grafts(G-PB). Cox regression analysis was used to determine the related risk factors.

RESULTS

The median age of all 253 patients was 31 (18-56) years, including 128 cases with acute myeloid leukemia (AML), 95 cases with acute lymphocytic leukemia (ALL), and 30 cases with chronic myeloid leukemia (CML). According to primary diseases, 185 patients were classified in the standard -risk group and 68 cases in the high-risk group. Median follow-up time was 929 days (range: 48-1762 days) post-transplantation. Engraftment has been attained 252 (99.6%) recipients with the median time of granulocyte and platelet recovery 12 days (ranging from 9 to 45 days) and 16 days (ranging from 7 to 180 days), respectively. Cumulative incidences of acute GVHD was 33.2% with median time of 25 days (range: 13-88 days) after transplant. Multivariate analysis identified that low BMI was associated with an increased risk of grade III-IV acute GVHD (HR = 5.736, 95%CI 1.779-18.491, P = 0.003). There was no significant impact of BMI to other manifestations of GVHD, TRM, relapse or OS in different groups.

CONCLUSIONS

Our findings demonstrate a correlation between pre transplant BMI and clinical outcome post-transplant. Low BMI was associated with increased risk of severe acute GVHD in leukemia patients receiving haploidentical allo-HSCT. Meticulous supportive care pre-transplantation is required for low BMI patients.

[Advances in the target therapy of hematological malignancies]

With the rapid development of modern bio-medical technology, the pathogenesis of hematological malignancies including leukemia, lymphoma, myeloma has been illustrated with more and more attractive details. The diagnosis of hematological malignancies now becomes more precisely and clarified based on the progress than ever before, and the treatments of hematological malignancies keep the evolution in the way of integrating the novel molecular target drugs with conventional chemotherapy, radiotherapy, hematopoietic stem cell transplantation. The pivotal progress in the target therapy of hematological malignancies includes tyrosine kinase inhibitors for the treatment of chronic myeloid leukemia, CD20 monoclonal antibody treatment of B-cell lymphoma and CD20 positive leukemia, FLT3 inhibitors fo the treatment of FLT3 mutation positive high-risk acute myelogenous leukemia. The topics of this issue focus on the advances in this field, which reflects the new achievements in the research of hematological malignancies, and the trends of precise and stratified diagnosis as well as tailored target therapy in the future.