[Clinical Significance of Minimal Residual Disease in Pediatric Patients with TCF3/PBX1+ B-cell Acute Lymphoblastic Leukemia]

OBJECTIVE

To explore the consistency of flow cytometry (FCM) method and polymerase chain reaction (PCR) technique in the detection of minimal residual disease (MRD) at different treatment stages in pediatric patients with TCF3/PBX1+ B-cell acute lymphoblastic leukemia (B-ALL) and the correlations between the detection results and prognosis.

METHODS

The clinical data of 64 newly diagnosed pediatric patients with TCF3/PBX1+ B-ALL admitted to the Department of Pediatrics of Peking University People's Hospital from January 2005 to December 2017 were retrospectively analyzed. FCM and PCR methods were used to monitor the MRD level in bone marrow samples from 64 children during the same period of treatment on d33 and d90 respectively, and the detection results were analyzed.

RESULTS

There were 37 males and 27 females in the 64 patients, with a median age of 8 years(range 0.8 to 16 years). The complete remission (CR) rate after the first cycle of induction chemotherapy was 98.4% (62/63), with overall CR rate of 100%. 12 patients experienced recurrence, with a median recurrence time of 16.9 (5.3-46.3) months. The median follow-up time of the 64 patients was 77.2 (1.0-184.8) months , and the 5-year overall survival (OS) rate and event-free survival (EFS) rate were 82.8%±4.7% and 75.0%±5.4%, respectively. On d90, the concordance rate of the MRD results from the two methods was 98.4%, and the related kappa value was 0.792 (P < 0.001), which were significantly higher than those on d33. After induction chemotherapy (d33), the 5-year EFS rate of MRD-FCM- group (79.3%±5.3%) was significantly better than that of MRD-FCM+ group (40.0%±21.9%) (P =0.028), there were no significant differences in the 5-year OS rate and EFS rate between MRD-PCR+ group and MRD-PCR- group, and the 5-year EFS rate of MRD-FCM-/PCR- group (85.4%±5.5%) was significantly better than that of MRD-FCM+/PCR+ group (40.0 %±21.9%) (P =0.026).

CONCLUSION

In children with TCF3/PBX1+ B-ALL, the MRD results detected by FCM and PCR methods show good consistency, especially in consolidation therapy period (d90). The MRD level at the end of induction therapy (d33) is an important factor affecting the long-term prognosis, especially the MRD results detected by FCM method, which is significantly associated with prognosis.

Prognostic Significance of CD20 Expression in Children with Philadelphia Chromosome-Negative B-Cell Precursor Acute Lymphoblastic Leukemia

INTRODUCTION

The prognostic significance of CD20 in pediatric B-cell precursor acute lymphoblastic leukemia (BCP-ALL) remains unclear. Therefore, in this study, we evaluated the prognostic value of CD20 expression in leukemia blasts in pediatric BCP-ALL at our institute.

METHODS

Between 2005 and 2017, 796 children with newly diagnosed Philadelphia-negative BCP-ALL were enrolled consecutively; clinical characteristics and treatment outcomes were analyzed and compared between CD20-positive and CD20-negative groups.

RESULTS

CD20 positivity was observed in 22.7% of enrolled patients. The analysis of overall and event-free survival showed that white blood cell count ≥50 × 109/L, no ETV6-RUNX1, day 33 minimal residual disease (MRD) ≥0.1%, and week 12 MRD ≥0.01% were independent risk factors. Meanwhile, in the CD20-positive group, week 12 MRD ≥0.01% was the only factor associated with long-term survival. Moreover, subgroup analysis revealed that in patients with extramedullary involvement (p = 0.047), MRD ≥0.1% on day 33 (p = 0.032), or MRD ≥0.01% at week 12 (p = 0.004), CD20 expression led to a poorer outcome compared to those without CD20 expression.

CONCLUSIONS

Pediatric BCP-ALL with CD20 expression had unique clinicopathological characteristics, and MRD remained the major prognostic factor. CD20 expression had no prognostic value in pediatric BCP-ALL.

Clinical analysis of pediatric T-cell acute lymphoblastic leukemia using the MRD-oriented strategy system

Pediatric T-cell acute lymphoblastic leukemia (T-ALL) has historically been associated with a poor prognosis. However, prognostic indicators and methods of treatment used for T-ALL remain controversial. A total of 136 children newly diagnosed with T-ALL between 2005 and 2018 were consecutively enrolled in this study. We assessed the effect of different prognostic factors, such as clinical characteristics, minimal residual disease (MRD), and the role of transplantation in postremission treatment, as the outcomes. Compared with B-ALL patients, patients with T-ALL are generally older, more likely to be male and have a higher white blood cell count. The complete remission (CR) rate was 95.6%, while the 5-year overall survival (OS), event-free survival (EFS), and cumulative incidence of relapse (CIR) were 74.3 ± 3.7%, 71.3 ± 3.9%, and 24.4 ± 3.8%, respectively. In the multivariate analysis, day 33 MRD ≥0.1% and hyperleukocytosis were associated with a significantly worse prognosis in the whole group. Transplantation resulted in a significant survival advantage, compared with chemotherapy, for high-risk (HR) patients (5-year CIR: 15.6 ± 10.2% vs. 55.6 ± 11.7%, P = .029). The prognosis of children with T-ALL was poor, and the MRD on day 33 was found to be an important predictive factor of clinical outcome at our center.

[Mid-term efficacy of China Net Childhood Lymphoma-mature B-cell lymphoma 2017 regimen in the treatment of pediatric Burkitt lymphoma]

Objective: To analyze the clinical characteristics of children with Burkitt lymphoma (BL) and to summarize the mid-term efficacy of China Net Childhood Lymphoma-mature B-cell lymphoma 2017 (CNCL-B-NHL-2017) regimen. Methods: Clinical features of 436 BL patients who were ≤18 years old and treated with the CNCL-B-NHL-2017 regimen from May 2017 to April 2021 were analyzed retrospectively. Clinical characteristics of patients at disease onset were analyzed and the therapeutic effects of patients with different clinical stages and risk groups were compared. Survival analysis was performed by Kaplan-Meier method, and Cox regression was used to identify the prognostic factors. Results: Among 436 patients, there were 368 (84.4%) males and 68 (15.6%) females, the age of disease onset was 6.0 (4.0, 9.0) years old. According to the St. Jude staging system, there were 4 patients (0.9%) with stage Ⅰ, 30 patients (6.9%) with stage Ⅱ, 217 patients (49.8%) with stage Ⅲ, and 185 patients (42.4%) with stage Ⅳ. All patients were stratified into following risk groups: group A (n=1, 0.2%), group B1 (n=46, 10.6%), group B2 (n=19, 4.4%), group C1 (n=285, 65.4%), group C2 (n=85, 19.5%). Sixty-three patients (14.4%) were treated with chemotherapy only and 373 patients (85.6%) were treated with chemotherapy combined with rituximab. Twenty-one patients (4.8%) suffered from progressive disease, 3 patients (0.7%) relapsed, and 13 patients (3.0%) died of treatment-related complications. The follow-up time of all patients was 24.0 (13.0, 35.0) months, the 2-year event free survival (EFS) rate of all patients was (90.9±1.4) %. The 2-year EFS rates of group A, B1, B2, C1 and C2 were 100.0%, 100.0%, (94.7±5.1) %, (90.7±1.7) % and (85.9±4.0) %, respectively. The 2-year EFS rates was higher in group A, B1, and B2 than those in group C1 (χ²=4.16, P=0.041) and group C2 (χ²=7.21, P=0.007). The 2-year EFS rates of the patients treated with chemotherapy alone and those treated with chemotherapy combined with rituximab were (79.3±5.1)% and (92.9±1.4)% (χ²=14.23, P<0.001) respectively. Multivariate analysis showed that stage Ⅳ (including leukemia stage), serum lactate dehydrogenase (LDH)>4-fold normal value, and with residual tumor in the mid-term evaluation were risk factors for poor prognosis (HR=1.38,1.23,8.52,95%CI 1.05-1.82,1.05-1.43,3.96-18.30). Conclusions: The CNCL-B-NHL-2017 regimen show significant effect in the treatment of pediatric BL. The combination of rituximab improve the efficacy further.

Impacts of vegetation on particle concentrations in roadside environments

In roadside environments, commuters are exposed to a high level of traffic-related pollution. Despite vegetation is often used to mitigate air pollution in road environments, its air quality impacts are complex and could be both positive or negative depending on specific conditions. This study conducted field measurements to assess the air quality impacts of roadside vegetation. Three common street vegetation configurations (dense vegetation, porous vegetation, and clearing) were selected and the concentrations of size-resolved particles and black carbon were measured. Results show that dense vegetation formed an accumulation area of particle pollutants on the sidewalk and bikeway, which was attributable to the increased deposition of pollutants. Compared with porous vegetation, the increase in particle concentrations before dense vegetation was 0-35% on the sidewalk (closer to vegetation) and 0-6% on the bikeway. Due to high homogeneity, fine particles (0.3-1 μm) showed low variability among different sample points, while coarse particles (>1 μm) showed high variability and presented a significant increase in concentration before dense vegetation. Porous vegetation showed weak interception effects on pollutants, and the particle concentrations before porous vegetation were close to those in the clearing. The horizontal decay of particle concentrations in porous and dense vegetation showed that particle pollutants were difficult to penetrate dense vegetation, which concentrations of particles presented a pronounced increase in the front part (0-5 m) of dense vegetation but also showed a large drop across it. These results suggest that vegetation serves as a good filter to clean the air and could improve the air quality away from the vegetation but could also worsen the air quality close to the vegetation. This study provides an insight into the environmental impacts of roadside vegetation, which could have practical implications in air pollution abatement.

Predictive impact of residual disease detected using multiparametric flow cytometry on risk stratification of paediatric acute myeloid leukaemia with normal karyotype

INTRODUCTION

Residual disease (RD) detected using multiparametric flow cytometry (MFC) is an independent predictive variable of relapse in acute myeloid leukaemia (AML). However, RD thresholds and optimal assessment time points remain to be validated.

MATERIAL AND METHODS

We investigated the significance of RD after induction therapy in paediatric AML with normal karyotype between June 2008 and June 2018. Bone marrow samples from 73 patients were collected at the end of the first (BMA-1) and second (BMA-2) induction courses to monitor RD using MFC.

RESULTS

Presence of RD after BMA-1 and/or BMA-2 correlated with poor relapse-free (RFS) and overall survival at 0.1% RD cutoff level. Receiver operating characteristic curve showed that RD cutoff levels of 1.3% and 0.5% after BMA-1 and BMA-2, respectively, predicted events with the highest sensitivity and specificity. In multivariable analysis, RD after BMA-2 was the strongest independent risk predictor for poor RFS (hazard ratio 2.934; 95% confidence interval: 1.106-7.782; P = .031).

CONCLUSIONS

Our study therefore suggests that an RD level ≥0.5% after BMA-2 has a significant predictive impact on the prognosis of AML patients having normal karyotype and thus guide the stratification of treatment strategies.

Unmanipulated haploidentical hematopoietic stem cell transplantation is an excellent option for children and young adult relapsed/refractory Philadelphia chromosome-negative B-cell acute lymphoblastic leukemia after CAR-T-cell therapy

Although chimeric antigen receptor T-cell (CAR-T) therapy produces a high complete remission rate among patients with relapsed/refractory B-cell acute lymphoblastic leukemia, relapse remains an urgent issue. It is uncertain whether consolidative haploidentical-allogeneic hematopoietic stem cell transplantation (haplo-HSCT) is suitable for achieving sustainable remission. Therefore, we aimed to assess the efficacy and safety of bridging CAR-T therapy to haplo-HSCT. Fifty-two patients with relapsed/refractory Philadelphia chromosome-negative B-cell acute lymphoblastic leukemia who underwent haplo-HSCT after CAR-T therapy were analyzed. The median time from CAR-T therapy to haplo-HSCT was 61 days. After a median follow-up of 24.6 months, the 1-year probabilities of event-free survival, overall survival, and cumulative incidence of relapse were 80.1% (95% confidence interval (CI), 69.0-90.9), 92.3% (95% CI, 85.0-99.5), and 14.1% (95% CI, 10.7-17.4), respectively, while the corresponding 2-year probabilities were 76.0% (95% CI, 64.2-87.7), 84.3% (95% CI, 74.3-94.3), and 19.7% (95% CI, 15.3-24.0), respectively. No increased risk of 2-year cumulative incidence of graft-versus-host disease, treatment-related mortality, or infection was observed. A pre-HSCT measurable residual disease-positive status was an independent factor associated with poor overall survival (hazard radio: 4.201, 95% CI: 1.034-17.063; P = 0.045). Haplo-HSCT may be a safe and effective treatment strategy to improve event-free survival and overall survival after CAR-T therapy.

Re-Emergence of Minimal Residual Disease Detected by Flow Cytometry Predicts an Adverse Outcome in Pediatric Acute Lymphoblastic Leukemia

Purpose

While the role of minimal residual disease (MRD) assessment and the significance of achieving an MRD-negative status during treatment have been evaluated in previous studies, there is limited evidence on the significance of MRD re-emergence without morphological relapse in acute lymphoblastic leukemia (ALL). We sought to determine the clinical significance of MRD re-emergence in pediatric ALL patients.

Methods

Between 2005 and 2017, this study recruited 1126 consecutive patients newly diagnosed with ALL. Flow cytometry was performed to monitor MRD occurrence during treatment.

Results

Of 1030 patients with MRD-negative results, 150 (14.6%) showed MRD re-emergence while still on morphological complete remission (CR). Patients with white blood cell counts of ≥50 × 10⁹/L (p = 0.033) and MRD levels of ≥0.1% on day 33 (p = 0.012) tended to experience MRD re-emergence. The median re-emergent MRD level was 0.12% (range, 0.01–10.00%), and the median time to MRD re-emergence was 11 months (range, <1–52 months). Eighty-five (56.6%) patients subsequently developed relapse after a median of 4.1 months from detection of MRD re-emergence. The median re-emergent MRD level was significantly higher in the relapsed cohort than in the cohort with persistent CR (1.05% vs. 0.48%, p = 0.005). Of the 150 patients, 113 continued to receive chemotherapy and 37 underwent transplantation. The transplantation group demonstrated a significantly higher 2-year overall survival (88.7 ± 5.3% vs. 46.3 ± 4.8%, p < 0.001) and cumulative incidence of relapse (23.3 ± 7.4% vs. 64.0 ± 4.6%, p < 0.001) than the chemotherapy group.

Conclusions

MRD re-emergence during treatment was associated with an adverse outcome in pediatric ALL patients. Transplantation could result in a significant survival advantage for these patients.

The role of minimal residual disease in specific subtypes of pediatric acute lymphoblastic leukemia

Acute lymphoblastic leukemia (ALL) is a heterogeneous disease whose prognostic factors include minimal residual disease (MRD) and cytogenetic abnormalities. To explore the significance of MRD in ALL subtypes, we analyzed the outcomes of 1126 children treated with risk-stratified therapy based on sequential MRD monitoring. MRD distributions and treatment outcomes differed between distinct leukemia subtypes. Patients with ETV6-RUNX1 or hyperdiploidy had the best prognosis (5-year OS: 97 ± 1.5% and 89.2 ± 2.7%). However, hyperdiploidy patients with MRD ≥ 10% on day 15 had a higher risk of relapse (36.4%) than those with ETV6-RUNX1. TCF3-PBX1 patients had the fastest disease clearance (negative MRD rate on day 33: 92.1%), but the overall prognosis was intermediate (5-year OS: 82.5%). Patients with high-risk characteristics and ALL-T had inferior outcomes: even with undetectable MRD on day 33, cumulative incidence of relapse was 19.9% and 23.4%, respectively. Moreover, those with poor early-treatment response and detectable week-12 MRD had a worse prognosis. After adjusting for other risk factors, re-emergent MRD was the most significant adverse prognostic indicator overall. Sequential MRD measurement is important for MRD-guided therapy, and integration of MRD values at different timepoints based on leukemia subtype could allow for more refined risk stratification.

[Interpretation for the group standards in technical specification for health risk investigation of central air conditioning ventilation system during coronavirus disease 2019 epidemic]

The central air conditioning ventilation system plays an important role in the air circulation of buildings such as centralized isolation medical observation points and general public buildings. In order to meet the requirements of COVID-19 epidemic prevention and control, Beijing Preventive Medicine Association organized Beijing CDC and other professional institutes to write up the group standard entitled "Technical specification for health risk investigation of central air conditioning ventilation system during the COVID-19 epidemic (T/BPMA 0006-2020)" . According to the particularity of central air conditioning ventilation system risk control during the outbreak of similar respiratory infectious diseases, based on current laws and regulations and the principle of scientific, practical, consistency and normative, 8 key points of risk investigations were summarized, which were the location of fresh air outlet, air conditioning mode, air return mode, air system, air distribution, fresh air volume, exhaust and air conditioner components. The contents, process, method, data analysis and conclusion of the investigation implementation were also defined and unified. It could standardize and guide institutions such as disease control and health supervision to carry out relevant risk managements, and provided solutions and technical supports for such major public health emergencies in city operations.

Retrospective analysis of data from 73 patients with childhood acute promyelocytic leukaemia receiving modified chemotherapy: a single-centre study

PURPOSE

Early death (ED) and treatment-related toxicity emerge as two major barriers for curing paediatric acute promyelocytic leukaemia (APL) patients. This study aims to investigate the effect of idarubicin on controlling hyperleukocytosis in induction therapy and the efficacy and safety of a risk-adapted attenuated consolidation chemotherapy.

METHODS

We summarised the characteristics and long-term outcomes of 73 paediatric APL patients treated at our institution from February 2002 to October 2018, during which treatment protocols evolved over three periods and were defined as protocol A, B and C chronologically. All of the patients received an all-trans retinoic acid (ATRA)-arsenic trioxide (ATO) combination remission induction therapy, with hydroxyurea (group A) or idarubicin (group B and C) to control hyperleukocytosis. Consolidation chemotherapy was modified with risk-adapted attenuated intensity and minimised cumulative doses of anthracyclines for group C (144 mg/m² and 288 mg/m² of daunorubicin equivalents for standard- and high-risk patients, respectively).

RESULTS

The median initial WBC, platelet count, and fibrinogen were 2.9 × 10⁹/L (range 0.9-158.3 × 10⁹/L), 32 × 10⁹/L (range 4-226 × 10⁹/L), and 160 mg/dL (range 53-549 mg/dL), respectively. High-risk and standard-risk were seen in 20.5% and 79.5% of patients, respectively. Three patients (4.1%) suffered early haemorrhagic death. At the end of induction therapy, 68 (93.2%) patients achieved haematologic complete remission (HCR). At a median follow-up of 91.97 months, the estimated 5-year overall survival (OS) and event-free survival (EFS) rates for the whole cohort were 95.9 ± 2.3% and 88.7 ± 3.8%, respectively. A comparison of HCR rates and documented instances of toxicity between groups A and B + C showed no significant differences. However, idarubicin significantly reduced the peak WBC count (Z = - 3.292, P = 0.001) and duration of hyperleukocytosis (Z = - 2.827, P = 0.005). Estimated 3-year EFS (91.7 ± 8.0%) and OS (100%) rates for group C were not significantly different from those for group B, whereas the risk of treatment-related infections was significantly reduced (χ² = 5.515, P = 0.019).

CONCLUSIONS

Idarubicin (8-10 mg/m²/day for 2 days) for hyperleukocytosis control in induction therapy is safe and effective for paediatric APL. Risk-adapted attenuated consolidation chemotherapy is advocated.

Prognostic Impact of Extramedullary Infiltration in Pediatric Low-risk Acute Myeloid Leukemia: A Retrospective Single-center Study Over 10 Years

BACKGROUND

The impact of extramedullary infiltration (EMI) on the clinical outcomes of pediatric patients with acute myeloid leukemia (AML) are controversial.

PATIENTS AND METHODS

A total of 214 pediatric patients with low-risk AML were classified as having EMI (central nervous leukemia [CNSL] and/or myeloid sarcoma [MS]) and not having EMI. Patients with isolated MS before AML diagnosis by bone marrow examination were confirmed with histopathologic examination. For patients diagnosed with AML by bone marrow examination, a thorough physical examination and radiologic imaging were used to confirm MS.

RESULTS

Male gender, a high white blood cell count, the FAB-M5 subtype, t(8;21) and t(1;11) abnormalities, and c-KIT mutations were associated with EMI. The presence of MS was associated with a low complete remission rate (63.6% vs. 79.4%; P = .000) and poor 3-year relapse-free survival (RFS) (62.6% ± 7.5% vs. 87.0% ± 2.8%; P = .000) and 3-year overall survival (73.5% ± 7% vs. 88.8% ± 2.6%; P = .011). Multivariate analysis revealed that MS was a poor prognostic factor for RFS and overall survival. Bone infiltration was an independent risk factor for inferior RFS with MS. Patients with CNSL had a low complete remission rate (58.3% vs. 77.2%; P = .045); however, CNSL did not significantly affect the survival of low-risk patients with AML.

CONCLUSION

MS should be considered an independent risk factor to guide stratified treatment.

Allogeneic hematopoietic stem cell transplantation can improve the prognosis of high-risk pediatric t(8;21) acute myeloid leukemia in first remission based on MRD-guided treatment

Background

Pediatric acute myeloid leukemia (AML) with t(8;21) (q22;q22) is classified as a low-risk group. However, relapse is still the main factor affecting survival. We aimed to investigate the effect of allogeneic hematopoietic stem cell transplantation (allo-HSCT) on reducing recurrence and improving the survival of high-risk pediatric t(8;21) AML based on minimal residual disease (MRD)-guided treatment, and to further explore the prognostic factors to guide risk stratification treatment and identify who will benefit from allo-HSCT.

Methods

Overall, 129 newly diagnosed pediatric t(8;21) AML patients were included in this study. Patients were divided into high-risk and low-risk group according to RUNX1-RUNX1T1 transcript levels after 2 cycles of consolidation chemotherapy. High-risk patients were divided into HSCT group and chemotherapy group according to their treatment choices. The characteristics and outcomes of 125 patients were analyzed.

Results

For high-risk patients, allo-HSCT could improve 5-year relapse-free survival (RFS) rate compared to chemotherapy (87.4% vs. 61.9%; P = 0.026). Five-year overall survival (OS) rate in high-risk HSCT group had a trend for better than that in high-risk chemotherapy group (82.8% vs. 71.4%; P = 0.260). The 5-year RFS rate of patients with a c-KIT mutation in high-risk HSCT group had a trend for better than that of patients with a c-KIT mutation in high-risk chemotherapy group (82.9% vs. 75%; P = 0.400). Extramedullary infiltration (EI) at diagnosis was associated with a high cumulative incidence of relapse for high-risk patients (50% vs. 18.4%; P = 0.004); allo-HSCT can improve the RFS (P = 0.009).

Conclusions

allo-HSCT can improve the prognosis of high-risk pediatric t(8;21) AML based on MRD-guided treatment. Patients with a c-KIT mutation may benefit from allo-HSCT. EI is an independent prognostic factor for high-risk patients and allo-HSCT can improve the prognosis.

Impact of tyrosine kinase inhibitors on the statural growth in children with acute lymphoblastic leukemia

PURPOSE

To investigate the effect of tyrosine kinase inhibitors (TKIs) on the statural growth in children with acute lymphoblastic leukemia (ALL).

METHODS

We retrospectively collected data from 344 children with ALL younger than 17 years old at diagnosis identified in pediatric department of Peking University People's Hospital. The children were divided into three groups: conventional chemotherapy group, imatinib group and dasatinib group. Height was expressed as standard deviation score(HtSDS). In the three groups, we compared the HtSDS and △HtSDS at the start of treatment and during follow-up period and also compared the adult height and median parental height(MPH). We further compared the HtSDS classified by age and gender in imatinib group. At last, univariate analysis was used to analyze the influencing factors on the deceleration of height growth by imatinib.

RESULTS

There were 298 children in conventional chemotherapy group, 39 in imatinib group and 7 in dasatinib group. In imatinib group, the mean HtSDS of children at follow-up time was significantly lower than that at the start of treatment (P < 0.05), regardless of age and gender. In imatinib group, the decrease of HtSDS in girls was more obvious than in boys(P = 0.031). The HtSDS gradually decreased in the first and the second year in imatinib group. After discontinuation of imatinib, the HtSDS had no obvious change. Multivariate analysis showed that the HtSDS at the start of imatinib was negatively correlated with severe growth impairment on imatinib therapy. The HtSDS in dasatinib group and conventional chemotherapy group maintained a high degree of consistency.

CONCLUSION

Imatinib can affect growth velocity in children with ALL, regardless of age and gender. With the discontinuation of imatinib, the inhibitory effect will not continue. The lower HtSDS at the start of imatinib therapy, the more obvious effect of imatinib on growth impairment will be, and the effect will be more obvious in girls than boys.

[Influence of dasatinib treatment on body height in children with acute myeloid leukemia]

OBJECTIVE

To study the influence of dasatinib treatment on body height in children with acute myeloid leukemia (AML).

METHODS

A retrospective analysis was performed for the clinical data of 86 AML children aged <17 years. According to the treatment regimen, these children were divided into a conventional chemotherapy group and a dasatinib chemotherapy group. The 57 children in the conventional chemotherapy group were given conventional chemotherapy drugs without tyrosine kinase inhibitor, and the 29 children in the dasatinib chemotherapy group were given conventional chemotherapy drugs and dasatinib. The two groups were compared in terms of height standard deviation score (HtSDS) at the beginning of treatment and after treatment, as well as the change in HtSDS after 1 and 2 years of treatment.

RESULTS

There was no significant difference in HtSDS between the conventional and dasatinib chemotherapy groups before treatment. Within the first two years of treatment, the dasatinib chemotherapy group had a similar change trend of HtSDS as the conventional chemotherapy group. Four children in the dasatinib chemotherapy group reached the final adult height during follow-up, which was significantly lower than the target height (P=0.044). In the conventional chemotherapy group, there was no significant difference between final adult height and target height. In the dasatinib chemotherapy group, the children in adolescence had a significant change in HtSDS after treatment (P=0.032).

CONCLUSIONS

Dasatinib treatment may affect the final height of children with AML, and the use of dasatinib after the beginning of adolescence may lead to growth disorder, but dasatinib treatment has little effect on body height in the short-term treatment.

[Chimeric antigen receptors T cells for treatment of 48 relapsed or refractory acute lymphoblastic leukemia children: long term follow-up outcomes]

Objective: To evaluate the safety and efficacy of chimeric antigen receptors T cells (CAR-T) in childhood acute B lymphoblastic leukemia (B-ALL) to probe the prognosis-related factors. Methods: Forty-eight children, 29 boys and 19 girls, aged 3-17years old (median age was 8 years old) , with recurrent or refractory CD19 positive B-ALL, were treated by the CD19 specific CAR-T cells. A total of 48 cases received 61 infusions. Flow cytometry or real-time quantitative polymerase chain reaction method were used to monitor micro residual disease (MRD) . The follow-up period was from 16 to 1 259 days with the median follow-up of 406 days. SPSS software was used to statistical analysis. Results: No adverse reaction was observed during 61 infusions. The most common adverse reaction after CAR-T cell infusions was cytokine-release syndrome (CRS) . Only 2 cases experienced level 3 CRS performance, including continuous high fever, convulsions, delirium, serous cavity effusion, and decreasing of blood pressure. Tocilizumab was given to release CRS performance. No treatment-related death occurred. Thirty-seven patients showed response during 7 to 28 days after infusions. The early response rate was 77.1%, with MRD before infusion less than 5% group higher than the MRD more than 5% group (87.1% vs 58.8%, χ2=4.968, P=0.036) . For the 37 patients who showed response to CAR-T cell infusions, univariate analysis identified that age, disease status at the time of treatment, MRD before infusion affected 2-year OS rate (P<0.05) . Multivariate prognostic analysis for EFS disclosed that the MRD before infusion more than 5% (RR=3.433, 95% CI 1.333-8.844, P=0.011) and not bridge to HSCT (RR=4.996, 95% CI 1.852-13.474, P=0.001) were the independent risk factors. Conclusion: The fourth generation CAR-T cells directed against CD19 could effectively and safely treat relapsed and refractory B-ALL, which implicated that CAR-T therapy as a novel therapeutic approach could be useful for patients with relapsed or refractory B-ALL who have failed all other treatment options. Reducing MRD as far as possible by effective pretreatment chemotherapy was in favor of increasing the response rate. Bridging HSCT after CAR-T cell treatment might be a better therapeutic strategy for the patient with refractory or molecular relapsed B-ALL.

[Prognostic factors of pediatric patients with Ph-positive acute lymphoblastic leukemia]

Objective: To explore the clinical features and prognostic factors of Ph-positive and/or BCR-ABL positive acute lymphoblastic leukemia (Ph⁺ ALL) in children. Methods: The clinical data of 68 Ph⁺ ALL children who were treated at Peking University People's Hospital from December 2006 to December 2016 was retrospectively reviewed. Survival analysis were estimated by Kaplan-Meier method. Univariate analysis was estimated by Log-rank test and Chi-square, and multivariate analysis was estimated by Cox proportional hazards regression model. Results: In the 68 cases, the proportion of male to female was 2.1∶1, with a median age of 8 (1-16) years, and the median overall survival (OS) and disease free survival (DFS) were 16.8 months and 13.5 months, respectively. The early response rate to treatment was 43.9%, with myeloid-antigens-expression group lower than the non-expression group (29.6% vs 61.3%, χ²=5.814, P=0.020); The complete remission (CR) rate after one-course induction therapy was 86.2% (56/65), with good-response group higher than the poor-response group (100.0% vs 74.2%, χ²=6.680, P=0.003);The CR rate after induction in patients receiving imatinib plus chemotherapy was higher than the patients receiving chemotherapy only (94.9% vs 73.1%, χ²=5.185, P=0.024). The 2-and 5-year OS were (61.4±7.0)% and (50.8±8.1)%, respectively. The 2-and 5-year DFS were (54.6±6.8)% and (48.6±7.3)%, respectively. Univariate analysis showed that the initial WBC, LDH, spleen size, liver size, with-myeloid-antigens-expression, early response to treatment, MRD (BCR-ABL) after one-course induction, application of imatinib and different treatment options affected 2-year OS rate (all P<0.05). LDH, spleen size, liver size, with-myeloid-antigens-expression, early response to treatment, MRD (BCR-ABL) after one-course induction, application of imatinib and different treatment options affected 2-year DFS rate (all P<0.05). Multivariate prognostic analysis for OS (RR=45.7, 95% CI 1.4-1 528.2, P=0.033) and DFS (RR=52.3, 95% CI 1.6-1 725.9, P=0.026) showed that the spleen ≥ 3 cm was the independent risk factor. Conclusions: Pediatric Ph⁺ ALL is a special condition with unique clinical and biological features. The early response to treatment was poor in patients with myeloid-antigens-expression, which resulted in a low CR rate after one-course induction and the administration of imatinib can remarkably improve the CR rate. Initial spleen ≥ 3 cm is an independent prognostic factor. The efficacy of chemotherapy alone is poor, and imatinib combined with chemotherapy is applauded in the aim of improving outcomes.

[Study on the three-dimensional mapping to reduce the X-ray exposure dose of interventional doctors in radiofrequency catheter ablation of atrioventricular nodal reentry tachycardia]

Objective: To explore the advantage of radiofrequency catheter ablation under the three-dimensional mapping in the treatment of atrioventricular nodal reentrant tachycardia (AVNRT) in reducing the X-ray exposure dose of interventional doctors. Methods: 79 patients with AVNRT, in the first hospital of Shanxi Medical University from January 2015 to June 2016, performed to do radiofrequency catheter ablation treatment were selected, and according to the random number method were divided into two-dimensional mapping group and three-dimensional mapping group. The two-dimensional mapping group was mapped the ablation target at the X-ray, while the ablation target was mapped by CARTO 3 system in the three-dimensional mapping group. Compare the X-ray fluoroscopy time, success rate, complications rate and doctor's X-ray exposure dose between the two groups. Results: Compared with the two-dimensional mapping group, acute success rate and complication rate of the three dimensional mapping group were not statistically significant (P>0.05) , while the X-ray fluoroscopy time and the X-ray dose of the three-dimensional mapping group decreased significantly, the difference was statistically significant (P<0.05) . Conclusion: Three-dimensional mapping can significantly reduce the X-ray irradiation time and interventional doctor's X-ray exposure dose in radiofrequency catheter ablation of AVNRT patients and the potential hazards of ionizing radiation on the human body.

[Preliminavy clinical study of the treatment of hemorrhoids by superselective embolization of superior rectal artery]

Objective: To investigate the safety and feasibility of the treatment of hemorrhoids by superselective arterial embolization. Methods: The clinical data of 15 patients with grade Ⅱ to Ⅳ hemorrhoids were collected who were treated by superselective SRA embolization.According to the number and shape of SRA in the vicinity of the dentate line, chosed coils, PVA particles and gelfoam particles, ethanol and bletilla mixture of gelfoam particles for embolization.And intraoperative operations, postoperative complications, follow-up treatment results were observed. Results: The interventional procedures were successfully accomplished in all 15 cases.The operation time was (30±14) min, and the hospital stay was 1-7 (2.0±1.8) days after operation, and the patients recovered to normal life in 12 hours after the operation.Tenesmus (14/15), pain (5/15) and low fever (11/15) can alleviate without special treatment. All patients were follow up (19.0±2.6) months, bleeding symptoms were cured, there's no serious complications. Conclusion: The treatment of hemorrhoids by transcatheter superselective embolization of superior rectal artery is technically safe and feasible.

[The protective effect of alpha-2 adrenergic agonist on cranial nerve in rats with brain injury]

OBJECTIVE

To investigate the neuroprotective effect of α2 adrenergic agonist, dexmedetomidine on tumor necrosis factor α (TNF-α), interleukin-6 (IL-6) in brain tissue and serum S-100β protein level in traumatic brain injury rats.

METHODS

Seventy-two male Sprague-Dawley rats were randomly divided into sham operation group (group S), traumatic brain injury group (group C), and dexmedetomidine group (group D), 24 rats in each group; each of which was divided into 6, 12, 24 and 48 hours subgroup, 6 rats in each subgroup. Parietal brain contusion was produced by reformed Feeney method. The group S underwent sham operation without blunt force stroke; group D underwent blunt force stroke, then received loading dose of dexmedetomidine, 3 μg/kg with common jugular vein injection and continued infusion with 3 μg·kg(-1)·h(-1) for 2 hours. The total dosage of dexmedetomidine was 9 μg/kg with a volume of 4 ml; group C underwent 0.9% NaCl, 4 ml injection at the same time point with the same method. The S-100 protein activity in arteria cruralis serum was detected at the each time point by ELISA and TNF-α, IL-6 in the brain tissue were detected by ELISA.

RESULTS

There were no significant difference of TNF-α activity among time point of 6, 12, 24 and 48 h in group S ((2.07±0.06), (2.01±0.03), (2.11±0.05), and (2.08±0.04) pg/mg, F=1.147, P>0.05), no significant difference of IL-6 activity among the same time point ((4.03±0.06), (4.07±0.09), (4.06±0.04), and (4.55±0.09) pg/mg, F=1.176, P>0.05), and no significant difference of serum S-100β activity among the same time too ((0.37±0.07), (0.36±0.02), (0.35±0.06), and (0.39±0.11) μg/L, F=1.045, P>0.05). The above indexes in group C were higher than those in group S, and the above indexes in group D were higher than those in group S and lower than those in group C (all P<0.05).

CONCLUSION

Alpha-2 adrenergic agonist, dexmedetomidine could dramatically inhibit inflammatory reaction induced by traumatic brain injury in rats and protect brain tissue.

[Prognostic impact of loss of sex chromosomes in children with acute myeloid leukemia subtype M2]

OBJECTIVE

To study the relationship between loss of sex chromosomes and prognosis in children with acute myeloid leukemia (AML) M2 subtype.

METHODS

According to cytogenetic characteristics, 106 children with AML were divided into three groups: patients with normal karyotype (Group A, n=26), patients with abnormal karyotype who had no loss of sex chromosomes (Group B, n=52), and patients with abnormal karyotype who had loss of sex chromosomes (Group C, n=28). Prognosis was compared between the three groups.

RESULTS

The 5-year event-free survival (EFS) rates of Groups A, B, and C were (38.9±11.2)%, (59.3±7.3)%, and (66.5±10.5)%, respectively; the EFS of Group C was significantly higher than that of Group A (P=0.035). The 5-year overall survival (OS) rates of Groups A, B, and C were (54.3±13.5)%, (68.1±7.7)%, and (77.9±9.8)%, respectively (P>0.05). The 5-year EFS of 58 patients with t(8;21) was (63.3±7.3)%, significantly higher than that of patients with normal karyotype (P=0.015). All the 28 cases in Group C had t(8;21), and their 5-year EFS was not significantly different from that of patients with t(8;21) in Group B (P>0.05).

CONCLUSIONS

Loss of sex chromosomes is a favorable karyotype in children with AML M2 subtype and the patients in this group mostly have t(8;21). Why loss of sex chromosomes indicates a favorable prognosis is probably because it is accompanied by t(8;21) in the patients.

[A comparison of minimal residual disease in children with acute lymphoblastic leukemia of different genetic abnormalities]

OBJECTIVE

To study the changes of minimal residual disease (MRD) in children with B cell acute lymphoblastic leukemia (B-ALL) of different genetic abnormalities.

METHODS

Between February 2004 and April 2013, 271 newly diagnosed B-ALL pediatric patients who had finished the induction chemotherapy were enrolled in the study. The characteristics of changes in MRD in patients with different genetic abnormalities on the 15th day and at the end of the induction therapy were analyzed.

RESULTS

On the 15th day of the induction chemotherapy, the MRD positive proportion in patients with hyperdiploid was higher on all the three cut-off levels of MRD≥0.1%, 1% and 10% compared to patients without hyperdiploid (P<0.05), but there was no significant difference in the MRD positive proportion on the three levels of MRD between the TEL-AML1-positive and TEL-AML1-negative groups (P>0.05). On the end of induction chemotherapy, there was no significant difference in the MRD positive proportion on the three levels of MRD between the patients with and without hyperdiploid (P>0.05), neither between the BCR-ABL-positive and negative groups. The MRD positive proportion in TEL-AML1-negative patients was significantly higher than in TEL-AML1-positive patients on all three levels of MRD (P<0.05). The MRD positive proportion on two levels of MRD≥0.01% and 0.1% in E2A-PBX1-negative patients was significantly higher than in E2A-PBX1-positive patients (P<0.05).

CONCLUSIONS

Children with B-ALL of different genetic abnormalities have different MRD levels during, and at the end of, induction therapy. The prognostic significance of MRD may be related to the genetic abnormalities.

[Clinical features and etiological spectrum in children with pancytopenia]

OBJECTIVE

To study the clinical features and etiological spectrum of pancytopenia in children.

METHODS

The clinical data of 174 children with pancytopenia between September 2003 and January 2010 were retrospectively reviewed.

RESULTS

Pale face was the most common clinical manifestation (147 cases, 84.5%), followed by bleeding (87 cases, 50.0%) and fever (41 cases, 23.6%). Mild to moderate anemia, severe thrombocytopenia and mild leucopenia were common in complete blood count. Of the 174 children, pancytopenia was attributed to hematopoietic system diseases in 155 cases (89.1%) and non-hematopoietic system diseases (virus infections, systemic lupus erythematosus, hypersplenism and neuroblastoma) in 6 cases (3.4%). Aplastic anemia (91 cases, 52.3%) was the most common cause of pancytopenia, followed by myelodysplastic syndrome (37 cases, 21.3%), acute leukemia and other hematological tumours (11 cases, 6.3%) and hemophagocytic syndrome (6 cases, 3.4%). The cause of pancytopenia was not identified in 13 cases (7.5%).

CONCLUSIONS

Anemia, bleeding and fever are the main clinical manifestations of pancytopenia in children. Pancytopenia is mostly caused by aplastic anemia in children. Myelodysplastic syndrome, hematological tumours and hemophagocytic syndrome are also the common causes.

[Real-time quantitative study of minimal residual disease in childhood B cell acute lymphoblastic leukemia]

OBJECTIVE

The study was aimed to investigate the feasibility and clinical significance of quantitative detection of minimal residual disease (MRD) in childhood acute lymphoblastic leukemia (ALL) by real-time quantitative polymerase chain reaction (RQ-PCR).

METHODS

Clonal IgH gene rearrangements of samples at diagnosis were identified by standard PCR assay with consensus primers. Monoclonal IgH gene rearrangements were analyzed using DNAPLOT software. Upstream primers were designed with the Primer Express software and allele specific oligonucleotide developed complementary to the V-D or D-J junction. Samples at diagnosis were serially diluted to generate the patient specific standard curves. RQ-PCR method was used to quantify the MRD of the follow up samples collected at five time points during chemotherapy. To check the quantity and quality of DNA, the investigators used RQ-PCR analysis for the albumin gene.

RESULTS

Totally 16 monoclonal IgH gene rearrangements were identified from 34 patients with B-ALL. The analysis of the 16 monoclonal rearrangements showed that the most frequently used V segment was from V3 family and J segment from J4 and J6. The RQ-PCR sensitivity of 10(-4) to 10(-5) was mostly reached. Non-specific amplification was seen in 6 patients. The number of inserted and deleted nucleotides did not appear to be related to the sensitivity (P > 0.05). The correlation coefficients of all 16 standard curves were excellent (> or = 0.99). The mean slope of the standard curves was -3.4 +/- 0.37 and the mean intercept was 24.3 +/- 2.95. MRD analysis of follow up samples from the 16 patients showed an association between high degree of MRD and relapse. There was no apparent relationship between MRD degree at the end of induction chemotherapy and other high risk factors of ALL (P > 0.05).

CONCLUSION

The study showed that the above approach with RQ-PCR was applicable to clinical detection of MRD in childhood ALL. Quantitative and dynamic study of MRD was of prognostic importance.

Spinal neurokin3 receptors facilitate the nociceptive flexor reflex via a pathway involving nitric oxide

The present study examined the effects of intrathecal administration of neurokinin3 receptor agonists on the electrically-evoked nociceptive flexor reflex in decerebrate and spinalized adult rats. The reflex was evoked by stimulating the isolated sural nerve at an intensity that activates C fibers and was measured by recording the number of compound potentials in the ipsilateral hamstring muscles. Intrathecal senktide (1-30 nmol), a neurokinin3 receptor agonist, dose-dependently facilitated the reflex reaching a maximum effect of 230% of the baseline reflex at 10 nmol. SR 142801 (60 nmol), a non-peptide neurokinin3 receptor antagonist, blocked facilitation of the reflex induced by 10 nmol senktide, providing further support that the effect of senktide is mediated by neurokinin3 receptors. The intrathecal administration of senktide (10 nmol) did not alter the monosynaptic reflex elicited by stimulating the L5 dorsal root at an intensity that was at the threshold for activating A fibers. This indicates that the senktide-induced facilitation of the nociceptive flexor reflex was not at the level of the motor neuron. Pretreatment with N(G)-nitro-L-arginine methyl ester (30 nmol), a nitric oxide synthase inhibitor, attenuated the effect of senktide, indicating that facilitation of the reflex by senktide is also mediated by the production of nitric oxide. Data from the present work have shown that spinal neurokinin3 receptors facilitate the nociceptive flexor reflex through a pathway that involves interneurons and the production of NO. Therefore, neurokinin3 receptors are likely to be involved in enhancing nociceptive neurotransmission at the level of the spinal cord.

Spinal NK2 receptors contribute to the increased excitability of the nociceptive flexor reflex during persistent peripheral inflammation

The role of endogenous neurokinin A in changes in the excitability of spinal neurons during adjuvant-induced, peripheral inflammation was examined by determining the effect of a selective NK2 receptor antagonist, GR103537, on the nociceptive flexor reflex in rats. Intrathecal administration of GR103537 (1.4-14 nmol) dose-dependently attenuated the increased activity of the flexor reflex ipsilateral to the inflamed paw. The activity of GR103537 at NK2 receptors was confirmed by blockade of the facilitation of the reflex by neurokinin A but not substance P in normal rats. These results indicate that endogenous neurokinin A increases the excitability of spinal neurons during persistent peripheral inflammation.

Spinal NK1 receptors contribute to the increased excitability of the nociceptive flexor reflex during persistent peripheral inflammation

Hyperalgesia is a characteristic of inflammation and is mediated, in part, by an increase in the excitability of spinal neurons. Although substance P does not appear to mediate fast synaptic events that underlie nociception in the spinal cord, it may contribute to the hyperalgesia and increased excitability of spinal neurons during inflammation induced by complete Freund's adjuvant. We examined the role of endogenous substance P in changes in the excitability of spinal neurons during adjuvant-induced, peripheral inflammation by determining the effect of a selective NK1 receptor antagonist (RP67580) on the nociceptive flexor reflex in adult rats. Experiments were conducted 2 or 3 days after injection of adjuvant. Animals exhibited moderate thermal hyperalgesia at this time. The flexor reflex was evoked by electrical stimulation of the sural nerve and was recorded in the ipsilateral hamstring muscles. The flexor reflex ipsilateral to the inflamed hindpaw was enhanced approximately two-fold compared to the flexor reflex evoked in untreated animals as determined by the number of potentials and the duration of the reflex. The enhanced reflex in adjuvant-treated animals was most likely due to an increase in the excitability of spinal interneurons because short-latency activity in the hamstring muscles did not differ between untreated animals and adjuvant-treated animals following electrical stimulation of the L5 dorsal root or the nerve innervating the muscle with a stimulus that was 1.3-1.5 times the threshold for excitation of A-fibers. Intrathecal administration of RP67580 (2.3 and 6.8 nmol) attenuated the flexor reflex evoked in adjuvant-treated animals, but had no effect in untreated animals. Intravenous or intraplantar injection of RP67580 (6.8 nmol) did not affect the flexor reflex in adjuvant-treated animals indicating a spinal action of the drug following intrathecal administration. RP68651, the enantiomer of RP67580, was without effect at doses up to 6.8 nmol, indicating that the effects of comparable doses of RP67580 were due to an action of the drug at NK1 receptors. However, intrathecal administration of 23 nmol of both drugs attenuated the reflex in adjuvant-treated and control animals indicating that effects of RP67580 at this dose were not mediated entirely by its action at NK1 receptors. Overall, these data suggest that endogenous substance P has a role in the increased excitability of spinal interneurons observed during persistent inflammation and support the hypothesis that substance P released in the spinal cord contributes to the hyperalgesia that accompanies adjuvant-induced persistent, peripheral inflammation.