Diagnostic performance of a multiplexed gastrointestinal PCR panel for identifying diarrheal pathogens in children undergoing hematopoietic stem cell transplant.

BACKGROUND: Diarrhea is a common complication of hematopoietic stem cell transplantation (HSCT) and is associated with substantial morbidity, but its etiology is often unknown. Etiologies of diarrhea in this population include infectious causes, chemotherapy- or medication-induced mucosal injury and graft-versus-host disease (GVHD). Distinguishing these potential causes of diarrhea is challenging since diarrheal symptoms are often multifactorial, and the etiologies often overlap in transplant patients. The objectives of this study were to evaluate whether the FilmArray gastrointestinal (GI) panel would increase diagnostic yield and the degree to which pre-transplantation colonization predicts post-transplantation infection. METHODS: From November 2019 to February 2021, a total of 158 patients undergoing HSCT were prospectively included in the study. Stool specimens were obtained from all HSCT recipients prior to conditioning therapy, 28 ± 7 days after transplantation and at any new episode of diarrhea. All stool samples were tested by the FilmArray GI panel and other clinical microbiological assays. RESULTS: The primary cause of post-transplantation diarrhea was infection (57/84, 67.86%), followed by medication (38/84, 45.24%) and GVHD (21/84, 25.00%). Ninety-five of 158 patients were colonized with at least one gastrointestinal pathogen before conditioning therapy, and the incidence of infectious diarrhea was significantly higher in colonized patients (47/95, 49.47%) than in non-colonized patients (10/63, 15.87%) (P < 0.001). Fourteen of 19 (73.68%) patients who were initially colonized with norovirus pre-transplantation developed a post-transplantation norovirus infection. Twenty-four of 62 (38.71%) patients colonized with Clostridium difficile developed a diarrheal infection. In addition, FilmArray GI panel testing improved the diagnostic yield by almost twofold in our study (55/92, 59.78% vs. 30/92, 32.61%). CONCLUSIONS: Our data show that more than half of pediatric patients who were admitted for HSCT were colonized with various gastrointestinal pathogens, and more than one-third of these pathogens were associated with post-transplantation diarrhea. In addition, the FilmArray GI panel can increase the detection rate of diarrheal pathogens in pediatric HSCT patients, but the panel needs to be optimized for pathogen species, and further studies assessing its clinical impact and cost-effectiveness in this specific patient population are also needed.

Human leukocyte antigen disparities reduce relapse after hematopoietic stem cell transplantation in children with juvenile myelomonocytic leukemia: A single-center retrospective study from China.

BACKGROUND: HSCT is the only proven curative therapy for JMML. Matching donor and recipient HLA alleles is considered optimal to reduce the risk of GVHD after HSCT but is not always possible. Only a limited number of studies have compared the influence of HLA disparities on HSCT outcomes for patients with JMML. METHODS: We conducted a retrospective study among 47 children with JMML who received related or unrelated unmanipulated HSCT (March 2010-October 2018). Among our participants, 27 (57.4%) donor-recipient pairs had 0-1 HLA disparities (Group 1: HLA-matched or ≤1 allele/antigen mismatch donor) and 20 (42.6%) had ≥2 HLA disparities (Group 2: 2-3 mismatched/haploidentical donors). RESULTS: The median follow-up period was 26.0 months (range: 1-105 months), and the 5-year probabilities of DFS and RI for the whole cohort were 54.6 ± 7.7% and 34.8 ± 15.0%, respectively. Compared to Group 1, Group 2 patients had a significantly lower RI (5.3 ± 10.5% vs 55.5 ± 20.9%, P Ë‚ .001), though similar rates of grade II-IV acute GVHD (60.0 ± 22.4% vs 33.3 ± 18.2%, P = .08), grade III-IV acute GVHD (25.0 ± 19.5% vs 7.4 ± 10.1%, P = .08), chronic GVHD (30.0 ± 20.9% vs 34.9 ± 18.8%, P = .85), NRM (20.0 ± 18.0% vs 3.9 ± 7.7%, P = .07), and DFS (74.4 ± 9.9% vs 41.3 ± 10.0%, P = .08). CONCLUSIONS: Disease relapse remains the major cause of treatment failure in JMML patients, especially in patients receiving HLA-matched and limited HLA-mismatched HSCT. Our findings suggest that donor-recipient HLA disparities may improve the outcome of HSCT in children with JMML.

ATG-Fresenius S combined with cyclosporine a: an effective immunosuppressive therapy for children with aplastic anemia.

For the first time, we conducted a 2-center retrospective study to show the efficacy of antithymocyte globulin (ATG)-Fresenius S plus cyclosporine treatment of children with severe aplastic anemia. From March 1997 to May 2011, a total of 124 patients (median age, 7.5 y; range, 1.5 to 16 y) from 2 centers with acquired AA treated with an immunosuppressive therapy (IST) regimen, consisting of ATG-Fresenius S (5 mg/kg per day for 5 d) and cyclosporine, were enrolled. The response rate was 55.6%. The median time between IST and response was 6 (0.5 to 18) months. After a median follow-up time of 29 (6 to 153) months, the rates of relapse and clonal evolution were 3.2% and 0.8%, respectively. Overall, 17 patients (13.7%) died in this study: 14 resulted from sepsis, 1 resulted from intracranial hemorrhage, 1 occurred after hematopoietic stem cell transplantation, and 1 resulted from clonal disease progression. The 5-year overall survival rate for the entire cohort was 74.7%. IST responders had a better survival rate (100%) than nonresponders (70.7%). The use of ATG-Fresenius S plus cyclosporine as a first-line immunosuppressive treatment appeared to be effective for children with severe aplastic anemia in our study. ATG-Fresenius S could be another option in the treatment arsenal, especially in countries where the other ATG products are harder to acquire.

[Long-term outcomes of childhood lymphoblastic lymphoma: report of 70 cases].

OBJECTIVE: To summarize long-term outcomes of childhood lymphoblastic lymphoma (LBL) with protocol CCCG-97 and -2002. METHODS: From November 1998 to October 2010, 70 consecutive newly diagnosed childhood LBL (5 B-LBL and 65 T-LBL) were enrolled in this study, in which 22 received CCCG-97 and 48 CCCG-2002 protocols. St.Jude staging system was adopted. Patients were divided into three risk groups based on clinical stage and serum LDH, and received chemotherapy with different intensity. The factors, which were possibly associated with the prognosis, were analyzed. The survival rates were evaluated by Kaplan-Meier analysis. RESULTS: The patients were 1.5 to 14 years old with the median age of 8 years old. They were evaluated as stage I-II for 6 , stage III41, and stage IV23 (15 were BM positive and 8 multiple bone metastases). Until Dec.31th, 2011,the mean follow-up was 62.5 months (range, 14 to 161 months) with the median follow-up of 48 months. 1-year overall survival (OS) was 74.3%, and 5- year event-free survival (EFS) 64.1% (abundance as event). Thirteen patients were complicated with serious condition during chemotherapy and 1 died of complication. Univariate analysis indicated that delayed and/or non-completed response on days 33 and 63 of induction was the unfavorable prognostic factor. CONCLUSION: Primary LBL usually located in the mediastinum. 90% of the patients was at advanced stage III-IV at first presentation. The 5-year EFS was 64.1%. Patients not achieved CR at days 33 and 63 at the end of induction was a poor prognostic factor.

[Long-term follow-up of childhood low-risk ALL patients treated with SCMC-ALL-2005 protocol].

OBJECTIVE: To evaluate the long-term efficacy of SCMC-ALL-2005 protocol in treatment of low-risk childhood acute lymphoblastic leukemia (ALL). METHODS: From May 1, 2005 to April 30, 2009, 387 patients enrolled into SCMC-ALL-2005 protocol. Based on the characteristics of cell morphology, immunology, cytogenetics and molecular biology and treatment response, 158 patients were fit into the low-risk treatment group. All the cases were registered in pediatric oncology network database (POND). The clinical characteristics and outcome were analyzed. RESULTS: Until December 31, 2012, the 5-year event free survival (EFS) and overall survival (OS) is (77.76±3.37)% and (89.55±2.83)%, respectively. Median follow-up time is 5.33 y (3.75-7.70 y). Five patients (3.16%) died of complication, all of them were severe infections. Twenty-seven patients (17.09%) relapsed, including 13 bone marrow relapse (8.23%), 5 testis relapse (5.32% of boys, 2 of unilateral and 3 bilateral), 6 central nerve system relapse (CNS, 3.80%), 1 relapse in both bone marrow and CNS, 1 relapse in both bone marrow and testis, and 1 right ovary and fallopian tube relapse. Relapse is related to positive minimal residual disease. Two cases (1.27%) occurred second tumors, 4 patients (2.53%) gave up treatment in complete remission without special reasons. CONCLUSION: The EFS and life quality of SCMC-ALL-2005 protocol in the treatment of childhood low-risk ALL is satisfactory. The treatment-related mortality rate is lower, and the long-term EFS is higher than that of XH-99 protocol.

[Therapeutic efficacy of allogeneic hematopoietic stem cell transplantation in children with chronic myelogenous leukemia].

OBJECTIVE: To investigate the therapeutic efficacy of allogeneic hematopoietic stem cell transplantation (allo-HSCT) in children with chronic myelogenous leukemia (CML), and to analyze the possible prognostic factors. METHODS: The clinical data of 20 children with CML who had received allo-HSCT was analyzed retrospectively to investigate possible prognostic factors, including age, sex, interval between diagnosis and transplantation, HLA matching between donors and recipients, illness status on transplantation and acute and chronic graft-versus-host disease (GVHD). RESULTS: At the end of follow-up, 13 of the 20 treated children had disease-free survival (DFS) and the rest (7 cases) died. Four died of severe acute GVHD, two of chronic GVHD and its complications, and one of relapse after transplantation. The three-year DFS was (64.6±1.1%). As shown by the univariate analysis, age was the most important prognostic factor in children with CML who had received allo-HSCT (P<0.05), and in children over 10 years, the prognosis was poor. No other of the above factors had a significant impact on prognosis (P>0.05). The multivariate logistic regression analysis also confirmed age as the only prognostic factor (P<0.01). Severe acute and/or chronic GVHD was the most important cause of patient death. 10/10 HLA-matched donors could improve the transplantation outcome. CONCLUSIONS: Allo-HSCT is an effective treatment for children with CML. To improve the prognosis and treatment outcome, children with CML aged over 10 years should receive allo-HSCT as early as possible. 10/10 HLA-matched donors are preferred in allo-HSCT and GVHD should be prevented.

[Evaluation on protocol SCMS-ALL-2005 for childhood B lineage acute lymphoblastic leukemia].

OBJECTIVE: To reduce the risk of therapy related complication during the treatment and keeps the long term event free survival, and to evaluate the results and risk factors of SCMC-lymphoblastic leukemia (ALL)-2005 protocol. METHODS: Designed the new protocol SCMC-ALL-2005 based on the previous protocol XH-99 for ALL. Divided the patients into low, median and high risk groups depends on risk factors including day 33 and 55 minimal residual disease (MRD) level. The higher risk group, the more intensive therapy was given. All the cases were registed on pediatric oncology network database (POND). All the abandonment patients were counted as event. From May 1(st) 2005 to April 30(th) 2009, 351 children who were newly diagnosed as B lineage ALL were enrolled in this study. The prognoses relating to risk grouping, age, mutation gene and MRD level were analyzed. RESULTS: Up to June 30, 2011, 273 patients were followed up with median time 49 months (range 26 to 74 months). Three hundred and forty-five patients (98.29%) achieved complete remission on day 35 induction. 12 cases were younger than 1 year old (3.42%), 285 cases between 1 and 9 years old (81.20%), 54 cases 10 to 18 years old (15.38%). Five year event-free survival (EFS) was 34%, 72% and 63%, respectively. One hundred and fifty-six cases belonged to lowered risk (44.44%), 177 to middle risk (50.43%) and 18 to higher risk (5.13%). Five year EFS was 78%, 64% and 30%, respectively. In this study, 18 patients were detected positive for BCR/ABL, 3 for MLL/AF4, 16 for PBX/E2A, and 36 for TEL/AML. The 5 year EFS were 11%, 66%, 75% and 74%, respectively. A total of 300 cases were tested for MRD levels on day 35. Of them, 241 cases were with MRD ≤ 0.01% (negative), and 59 cases > 0.01% (positive). The 5 year relapse free survival (RFS) was 79% and 58%, respectively. Total 6 patients died of complication (1.71%). 18 patients were abundant treatment with no disease progress. 70 patients relapsed (19.94%), including 52 bone marrow, 8 central nerve system (CNS), 1 both in bone marrow and CNS, 1 second cancer (M(4)) and 8 testis. Five year overall survival (OS) and EFS are 84% and 69%. CONCLUSIONS: The risk of therapy related death is low with the protocol SCMC-ALL-2005. MRD affects the prognosis. The long term prognosis is poor for high risk group, with BCR/ABL and positive MRD.

[Correlation between blood T-cell receptor rearrangement excision circles levels and severe infection in children with acute lymphoblastic leukemia].

OBJECTIVE: This study quantitatively examined signal joint T-cell receptor rearrangement excision circles (sjTRECs) levels in peripheral blood of children with acute lymphoblastic leukemia (ALL) at different stages in order to evaluate the role of sjTRECs in predicting severe infection postchemotherapy. METHODS: sjTRECs levels in peripheral blood were measured by fluorescent quantitation-polymerase chain reaction in 30 children with newly diagnosed ALL, 36 children with ALL who accepted chemotherapy but were not infected, 30 children with ALL who had severe infection after chemotherapy, and 50 normal children. RESULTS: Blood sjTRECs levels in the normal group (394 ± 270 copies/103 MNC) were significantly higher than those in the other three groups (P<0.05). Blood sjTRECs levels in the chemotherapy group without infection (96 ± 78 copies/103 MNC) were significantly lower than those in the newly diagnosed ALL group (210 ± 219 copies/103 MNC) (P<0.05). The chemotherapy group with severe infection showed the lowest blood sjTRECs levels (48 ± 40 copies/103 MNC) in the four groups. CONCLUSIONS: The measurement of blood sjTRECs levels might be helpful for predicting the occurrence of severe infection postchemotherapy in children with ALL.

[Analysis of clinical outcomes of 63 children with acute monocytic leukemia].

OBJECTIVE: To evaluate the outcomes of childhood acute monocytic leukemia (AML-M5) and explore the indications of allogeneic hematopoietic stem cell transplantation (allo-HSCT) for children with AML-M5. METHOD: Seventy-five AML-M5 patients and 201 non-AML-M5 AML patients were enrolled in this retrospective analysis. Event-free survival (EFS) and overall survival (OS) rates were estimated by Kaplan-Meier method and prognostic factors were evaluated by COX regression with SPSS. RESULT: (1) Twelve patients gave up treatment after confirmed diagnosis. Two patients died on the second day after chemotherapy. Of the 61 patients, 73.8% (45/61) achieved complete remission (CR) after two courses of chemotherapy. The 5-year EFS rate was 34.5% ± 6.8%. But of the 117 non-AML-M5/M3 AML patients, the 5-year EFS rate was 51.0% ± 4.9%. (2) Multivariate analysis showed that age ≥ 10 y, the proportion of bone marrow blast cell counts ≥ 15% after the first induction therapy, not CR after two courses of chemotherapy were risk factors for the long-term prognosis. (3) Of the 20 patients whose bone marrow blast cell counts ≥ 15% after the first induction therapy, 5 patients who choose allo-HSCT had a better OS than the other 15 patients who choose chemotherapy only (60.0% ± 21.9% vs. 7.3% ± 7.1%, P = 0.024). CONCLUSION: Children with AML-M5 had a poorer prognosis than the other AML patients; patients whose bone marrow blast cell counts ≥ 15% after the first induction therapy chose allo-HSCT had a better prognosis. At present, there is no enough evidence to support that patients whose bone marrow blast cell counts < 15% after the first induction therapy should choose unrelated donor for allo-HSCT.

[ALL-2005 protocol experience in the therapy of children and adolescents over 10 years of age with acute lymphoblastic leukemia].

OBJECTIVE: To explore the incidence, clinical characteristics and prognosis of children and adolescents over 10 years of age with acute lymphoblastic leukemia (ALL). METHODS: From May 1, 2005 to April 30, 2009, 67 newly diagnosed ALL children and adolescents over 10 years of age were enrolled in protocol of ALL-2005. All of the clinical characteristics of the patients were analyzed. The statistics was done by SPSS 13.0. RESULTS: There were 40 males (59.7%) and 27 females (40.3%). The mean age at diagnosis was 12.3 ± 1.7 (10.0 to 17.8) years with median age of 12.2 years. Of 67 patients, 48 were in medium risk group, and 19 in high risk group. During induction therapy, 83.6% and 86.6% patients had good response to prednisone and bone marrow blasts ≤ 5% at day 19, respectively. The overall hematologic response rate in these 67 patients was 88.1% (59) in complete remission (CR) after induction therapy, 15 patients relapsed with mean continuous CR period of (14.9 ± 9.9) months. The five-year event-free survivals (EFS) and overall survivals (OS) were (64.4 ± 6.3)% and (74.1 ± 6.1)%, respectively. According to univariate analysis, elevated serum ferritin, bcr-abl translocation, poor response to prednisone, high bone marrow blasts at day 19 or after induction therapy, and high minimal residual disease (MRD) after induction therapy increased risk for recurrence. Multivariate analysis indicated that high MRD after induction therapy was associated with recurrence (RR = 2.20, 95%CI 1.26 - 3.84, P < 0.01). CONCLUSION: Survival has improved for children and adolescents with ALL by ALL-2005 protocol. Analysis of serum ferritin and bcr-abl translocation at diagnosis, early responses to treatment and MRD detection during therapy are powerful prognostic indicators.

[Treatment outcomes of 125 children with aplastic anemia].

OBJECTIVE: To analyze the outcome of childhood aplastic anemia received allogenic hematopoietic stem cell transplantation (HSCT) and immunosuppressive therapy (IST). METHODS: The clinical data of 125 consecutive children with aplastic anemia (AA) in our hospital were retrospectively analyzed. RESULTS: According to the clinical manifestations, the 125 AA children were divided into two groups: SAA (n = 79) and NSAA (n = 46). There was no significant difference between the two groups in sex, age and follow-up duration (P > 0.05). The median follow-up was 25 (6 - 89) months. 103 cases received IST and 22 received allogenic HSCT. In SAA group, the response rate was better in patients received allogenic HSCT (n = 21) than in those received IST (n = 58) (85.7% vs 53.4%, P < 0.01). SAA patients received IST were further divided into two groups: 47 received antithymocyte globulin (ATG) and cyclosporine-A (CsA) combined therapy, 11 received CsA alone. There was no significant difference in total response rates (55.3% vs 45.5%, P = 0.555) and cure rates (42.6% vs 27.3%, P = 0.499) between the two groups. In NSAA group, 45 patients received IST and 1 received allogenic HSCT. In the IST treated NSAA patients, there was also no statistic significance in cure rates (36.4% vs 32.4%, P = 0.806) and total effective rates (63.6% vs 64.7%, P = 0.949) between ATG and CsA combined therapy (n = 11) and CsA alone therapy (n = 34). CONCLUSION: The outcome of children with AA received allogenic HSCT was obviously better than those received IST. IST is still the choice for patients without suitable donors for HSCT.

Outcome of Chinese children with unrelated donor hematopoietic stem cell transplantation.

BACKGROUND: To evaluate the prognostic factors and outcomes in Chinese children undergoing unrelated donor hematopoietic stem cell transplantation (UDT). METHODS: Retrospective analysis of clinical data from 53 consecutive children who received UDT from November 2002 to December 2007 in our center. RESULTS: The median recipient age was 8.4 years (range 1.5-21). With a median follow-up of 36 months (range 18-80), the probability of 3-year overall survival (OS) was 71.5%. Treatment-related mortality (TRM) was 19.0%, and 9.5% died after post-transplant leukemia relapse. Incidence of grades I-II, III-IV acute and chronic graft versus host disease (GVHD) was 63%, 29%, and 46%. There was significant difference in OS between patients older or younger than 10 years (50.0% vs. 84.8%, P = 0.003), patients with different underlying diseases (ALL, AML, CML, and non-malignant disease: 36.4%, 80.0%, 61.5%, and 100%, P = 0.001) and patients receiving either HLA 0-1 versus 2-3 loci high-resolution mismatched UDT (83.3% vs. 53.3%, P = 0.034). The OS was not affected by the stem cell source (peripheral stem cell 70.3%, bone marrow 87.5% vs. cord blood 62.5%, P = 0.542) or the severity of acute GVHD (grade 0-II 77.8% vs. grade III-IV 60.0%, P = 0.140). CONCLUSIONS: The important prognostic factors for OS after UDT were the degree of HLA match, the age of patient and the type of underlying disease. Patients < 10-year with non-malignant disease receiving 0-1 locus high-resolution mismatched UDT had the most favorable outcomes.

[Causes of deaths of children with malignant tumors during hospitalization in a single center].

OBJECTIVE: To investigate the main causes of deaths and the influencing factors in children with malignant tumors in the hospital, explore the possible way to improve the treatment. METHODS: Clinical data of 84 patients with malignant tumors who died during hospitalization in the Department of Hematology/Oncology from June 1999 to December 2008 were collected and retrospectively analyzed. Major causes of deaths and their influencing factors were analyzed. RESULTS: (1) Treatment related complications which occurred in 73 cases (86.9%) were the leading cause of death, including infection-related death which was the most common cause of 51 cases (60.7%), hemorrhage-related death occurred in up to 28 cases (33.3%), and acute tumor lysis syndrome (ATLS) related death occurred in 2 cases (2.4%), graft versus host disease (GVHD) related death after allogeneic hematopoietic stem cell transplantation occurred in 4 cases (4.8%). Moreover, primary diseases related death occurred in 30 cases (35.7%). (2) In this group, there were no significant differences in treatment phases when the death occurred among patients with leukemia (56 cases), lymphoma (9 cases) and other non-hematopoietic and lymphoid tissue tumors (7 cases, chi(2) = 4.784, P = 0.310). (3) The infection related death increased significantly when WBC count was lower than 1.0 x 10(9)/L, which is totally different from those whose WBC was higher than or equal to 1.0 x 10(9)/L (chi(2) = 25.486, P < 0.001). (4) Twenty-six cases were detected to be infected with definite pathogens; different pathogens were identified 36 times in the 26 patients. Gram-negative bacteria (15/36, 41.7%) were the most common pathogens, followed by fungal organisms (14/36, 38.9%) and gram-positive bacteria (7/36, 19.4%). CONCLUSION: More attention should be paid to the prevention and treatment of cancer therapy related complications in children with malignant tumors. Infection was the leading cause of death, gram-negative bacteria and fungi were predominating pathogens. Application of effective antibiotics and combined antifungal drugs timely, especially in the remission induction or first chemotherapy period as well as in the period of neutropenia, may reduce mortality of children with malignant tumors significantly.

[Relationship between the antileukemic activity of L-asparaginase and Asn level around leukemic cells].

OBJECTIVE: To study the antileukemic activity of L-asparaginase through determining the changes of 4 kinds of amino acids (Asn, Aspa, Glu and Gln) in cell culture medium. METHODS: Following L-Asp treatment with designed concentrations and duration, the IC50 (inhibitory concentration 50%) of 8 kinds of common leukemia cell lines (U937, HL-60, Jurkat, NB4, THP-1, Namalwa, Karpass299, K562) were determined by CCK-8 assay. The changes of the 4 kinds of amino acids mentioned above were detected by high performance liquid chromatography (HPLC). RESULTS: The asparagines in cell culture medium were rapidly exhausted when treated with 0.01 U/mL L-Asp for 4 hrs or 1 U/mL L-Asp for 5 minutes. There were significant differences in the sensitivities to L-Asp of different leukemia cell lines. The sensitivities to L-Asp of various cell lines were dose-dependent. Low concentration of L-Asp resulted in a low IC50 and the IC50 increased following the L-Asp concentration increased. CONCLUSIONS: Different leukemia cell lines have different sensitivities to L-Asp, suggesting that exhaustion of asparagines around leukemia cells could not reflect the treatment efficacy of L-Asp. L-Asp antileukemic activity is dose-dependent, which suggests the importance of high-dose L-Asp on childhood acute lymphoblastic leukemia.

[Relationship between asparagine synthetase expression level and cell sensitivity to L-asparaginase in human leukemic cell lines].

This study was purposed to explore the relationship between asparagine synthetase (AsnS) mRNA expression level and the sensitivity of leukemic cell lines to L-asparaginase. The AsnS mRNA expression level in 8 cell lines (Jurkat, HL-60, U937, NB4, THP-1, Namalwa, Karpas299 and K562) was determined by real-time quantitative PCR (RQ-PCR) based on fluorescence dye Eva Green before and after treatment with L-Asp, and the cell proliferation rates were analyzed by CCK-8 assay. The results showed that there was a significant disparity of AsnS expression level in 8 cell lines, and there were significant increases of AsnS expression level in cells co-cultured with L-Asp (p < 0.05). Of all these eight cell lines, cells sensitive to L-asparaginase had lower AsnS expression level and cells resistant to L-asparaginase had higher AsnS expression. U937 which was the most sensitive to L-asparaginase had the lowest AsnS expression level, while K562 was natural resistant to L-asparaginase and possessed of the highest AsnS level. It is concluded that the AsnS plays a critical role in regulating cellular biological behavior after depletion of asparagine, the AsnS mRNA expression level in cells reflects the sensitivity of cells to L-Asp. The results may imply the possibility for the use of L-asparaginase in leukemia with lower AsnS expression level.

[Outcome of 46 children with refractory leukemia treated with unrelated donor hematopoietic stem cell transplantation].

OBJECTIVE: To evaluate the efficacy of matched unrelated donor hematopoietic stem cell transplantation (UDT) and influencing factors in children with refractory leukemia. METHOD: Retrospective analysis was performed on clinical data of 46 consecutive children received UDT between Nov. 2002 and Dec. 2008. A 12-14 GY fractioned total body irradiation (TBI) was given to children with acute lymphoblastic leukemia (ALL). Busulphan based myeloablative regimen was applied to all the other patients. ATG (Fresenius) 15 - 20 mg/kg + low dose cyclosporine A oral [CSA, 8 - 12 mg/(kg * d) with serum trough levels 150 - 200 ng/ml] +/- methotrexate (without methotrexate for cord blood transplant) were administered as graft versus host disease (GVHD) prophylaxis. Mycophenolate mofetil [MMF, 20 - 30 mg/(kg * d)] was added for 13 CML after Jan 1, 2006 because of more severe GVHD was observed in this group. RESULTS: The median age was 8.0 (2 - 17) years with the median follow up period of 23.5 (0.7 - 85) months. The estimated 3 years overall survival (OS) was 63.0%; 23.9% patients died of transplant related mortality, 13.0% patients died of leukemia relapse. Cytomegalovirus (CMV) infection recurred in 50% patients and hemorrhagic cystitis in 15.2% patients; 33.3% patients developed grade III-IV acute GVHD and 55.6% developed chronic GVHD (13.9% with extensive chronic GVHD). The OS was significantly different between the patients older (n = 20) and younger (n = 26) than 10 years (45.0% vs. 76.9%, P = 0.015) and among the patients with ALL (n = 13), CML (n = 18) and AML (n = 15) (38.4%, 66.7% vs.80.0%, P = 0.034). The OS in patient with high risk leukemia (n = 24) was lower than that in the patient with low risk leukemia (n = 22) (45.8% vs. 81.8%, P = 0.012). Except 8 cord blood transplant the OS of patients with HLA 6/6 high resolution completely matched (n = 16) and 1/6 mismatched (n = 16) bone marrow and peripheral blood stem cell transplants was significantly higher than patients with 2/6 mismatched (n = 6) UDT (75.0%, 75.0% vs. 16.7%, P = 0.007). But the OS was not significantly different between patients with grade 0-II acute GVHD and III-IV acute GVHD (60.0% vs. 66.7%, P = 0.494). CONCLUSION: The outcome of UDT for Chinese children with refractory leukemia is encouraging. Patients younger than 10 years with 0-1/6 high resolution mismatched UDT had the best OS. The outcome of patients with myeloid and low risk leukemia is superior to those with other types of leukemia.

[Study of the correlation between the expression level of asparagine synthetase and the outcome of children with acute lymphocytic leukemia].

OBJECTIVE: To determine whether the high level of asparagine synthetase (AS) expression in childhood acute lymphocytic leukemia (ALL) is associated with an inferior prognosis. METHODS: AS mRNA level in leukemic cells from 53 newly diagnosed ALL children was measured by real time fluorescent quantitative PCR method. Patients were divided into groups according to their relapse risk and outcome, and the AS expression levels in each group were compared. The survival rates in different AS expressing level groups were estimated and compared. RESULTS: The highest level of AS [median 17.25 (2.48-46. 82)] was observed in children failed remission, intermediate level [14.28 (3.20-54.47)] in relapsed children and the lowest level [5.08 (0.84-54.92)] in children with continuous complete remission (CCR) (P<0.05). The AS mRNA level [14.93 (2.48-54.47)] in children with poor outcome (un-remission and relapsed) was significantly higher than that in children in CCR (P<0.01). The two-year estimated disease free survival was much lower in children with high AS expression (53.8%) than in those with low AS expression (84.6%) (P<0.05). CONCLUSION: High expression of AS is associated with a poor outcome in ALL children.

[Evaluation of a modified induction chemotherapy in children with acute lymphoblastic leukemia].

OBJECTIVE: To improve the treatment outcome of children with acute lymphoblastic leukemia (ALL), and to evaluate the efficacy and safety of a modified induction chemotherapy between the two protocols used to treat children with ALL in Shanghai Children's Medical Center. METHODS: From Jan. 1st, 1999 to Mar. 1st, 2006, 311 patients with newly diagnosed childhood ALL, who underwent induction chemotherapy for over 10 days, were eligible for analysis. Group 99 (n = 243) patients who were admitted before May 1st, 2005, were treated with ALL-XH-99 Protocol, whereas 68 patients admitted afterwards, defined as Group 05, were treated with ALL Protocol 2005 which was based on ALL-XH-99 Protocol but the treatment intensity was reduced to decrease treatment associated mortality. Clinically, the distributions of the initial data from the patients, treatment responses, complete remission rates after therapy, and treatment-associated infections in the two groups were evaluated. RESULTS: Patients from the two groups obtained similar complete remission rate (91.8% vs. 95.6%, P = 0.29), while patients from Group 05 were benefited more from their therapy. They had lower therapy associated infection rate (23.5% vs. 54.7% in Group 99, P < 0.01), and no severe infection (0 vs. 9.1% in Group 99) and no infection related death occurred (0 vs. 3.7% in Group 99). Patients in the Group 05 also had shortened period from the beginning day of the initial therapy to complete remission (32.34 +/- 3.36 days vs. 34.18 +/- 4.96 days, P < 0.01). CONCLUSIONS: ALL Protocol 2005 had the same efficacy as ALL-XH-99 Protocol had in the induction therapy in treating children with ALL, but it was safer than ALL-XH-99.

[Single nucleotide polymorphism in the promoter region of asparagine synthetase and its impact on the gene expression].

High expression of cellular asparagine synthetase (AS) is a causative factor for the resistance of leukemic cell to L-asparaginase therapy. This study was aimed to find single nucleotide polymorphism (SNPs) in the promotor region of asparagine synthetase (AS) gene and to determine if these SNPs have influence on the transcriptional activity of AS promotor. The DNA sequences of AS promoter (pAS) from 82 leukemic children and 45 controls were determined to screen for SNPs in this region and the AS mRNA level in these samples was quantified using real-time PCR assay. The results indicated that three SNPs were found in the sequenced pAS fragment. They were -239C/T, -92G/A and -62A/T respectively. The frequency of -92A allele was higher in leukemic samples than that in nonleukemic control (P<0.05). The gene expression level differed among the individuals with genotype of the -92G/A SNP, and the descending order was as follows: GA heterozygote > AA homozygote > GG homozygote. It is concluded that some features in leukemia might associate with SNP on -92A locus, and this SNP in pAS can be one of the factors influencing transcriptional activity of AS gene. The existence of the -92A allele variant contributes to a high expression of AS gene.

Homoharringtonine: a new treatment option for myeloid leukemia.

HHT, one of the alkaloids from a Chinese natural plant, Cephalotaxus, has shown its potential in leukemia treatment. This compound demonstrated strong growth-inhibiting activities in vitro and in animal experiments, and obtained encouraging results in some clonal proliferative disease such as in chronic myeloid leukemia (CML) and in polycythemia vera. Evidences also confirmed HHT as an apoptosis inducer in tumor cell lines and fresh cells from cancer patients. The CR rate reported with HHT-based regimen in acute nonlymphocytic leukemia showed no statistic differences from that with DNR-based regimen, although the case number was limited. While used in clinical trial, the drug often cause noticeably cardiovascular disturbances if be given rapidly by intravenous infusion. Myelosuppression is the common complication in HHT-based chemotherapy. Although with the anti-growth activity in vitro and praisable achievement in acute and chronic myeloid leukemia treatment, the drug shows no beneficial effect in lymphocytic leukemia and solid tumors. The underlying mechanism for the discrepancy of efficacy keeps unknown. This review will present with the preclinical research data including the action mechanism, pharmacokinetics and drug resistance of HHT as well as the result from the clinical trial with HHT in China and the United States.