Population Pharmacokinetics of Cyclosporine in Chinese Pediatric Patients With Acquired Aplastic Anemia.

Cyclosporine (CsA) is a component of the first-line treatment for acquired aplastic anemia (acquired AA) in pediatric patients. This study aimed to develop a population pharmacokinetic (PK) model of CsA in Chinese pediatric patients with acquired AA to inform individual dosage regimens. A total of 681 CsA whole blood concentrations and laboratory data of 157 pediatric patients with acquired AA were retrospectively collected from two hospitals in Shanghai. A nonlinear mixed-effect model approach was used to build the population PK model. Potential covariate effects of age, body weight, and biochemical measurements (renal and liver functions) on CsA PK disposition were evaluated. Model fit was assessed using the basic goodness of fit and a visual predictive check. The CsA concentration data were accurately described using a two-compartment disposition model with first-order absorption and elimination. Body weight value was implemented as a fixed allometric function on all clearance and volume of distribution parameters. Total bilirubin level was identified as a significant covariate on apparent clearance (CL/F), with a 1.07% reduction per 1 nmol/L rise in total bilirubin level. The final estimates for CL/F and central volume (Vc/F) were 29.1 L/h and 325 L, respectively, for a typical 28 kg child. Other covariates (e.g., gender, age, albumin, hemoglobin, hematocrit, serum creatinine, and concomitant medication) did not significantly affect the PK properties of CsA. This population PK model, along with a maximum a posteriori Bayesian approach, could estimate individual PK parameters in pediatric patients with acquired AA to conduct individual CsA therapy.

Potential protein-phenotype correlation in three lipopolysaccharide-responsive beige-like anchor protein-deficient patients.

BACKGROUND: Patients with lipopolysaccharide (LPS)-responsive beige-like anchor protein (LRBA) deficiency have a variety of clinical symptoms, but there is no apparent genotype-phenotype correlation, and patients carrying the same mutations may have different phenotypes. Therefore, it is not easy for doctors to make a decision regarding hematopoietic stem cell transplantation (HSCT) for LRBA-deficient patients. We hypothesized that there may be a protein-phenotype correlation to indicate HSCT for LRBA-deficient patients. AIM: To report on three Chinese LRBA-deficient patients and determine the correlation between residual protein expression and disease phenotypes. METHODS: Clinical data of three Chinese LRBA-deficient patients were collected, and protein levels were detected by Western blot analysis. In addition, LRBA mutation information of another 83 previously reported patients was summarized. RESULTS: All the major clinical findings indicated enteropathy, but patients 1 and 3 presented with more severe symptoms than patient 2. Endoscopy and histology indicated nonspecific colitis for patients 1 and 3 but Crohn's disease-like colitis for patient 2. Compound heterozygous mutations in LRBA were found in patient 1, and homozygous mutations in LRBA were found in patient 2 and patient 3. Only patient 2 responded well to traditional immunosuppressive treatment. Residual expression of the LRBA protein in patients 1 and 3 was very low, but in patient 2, a more than 0.5-fold in expression of the LRBA protein was found compared to that in the control. After HSCT, patient 1 had increased LRBA protein expression. We summarized the genetic information of 86 patients, and the mutations in patients 1 and 3 were novel mutations. CONCLUSION: We described three Chinese LRBA-deficient patients, two of whom carried novel mutations. These patients had no genotype-phenotype correlations, but their residual LRBA protein expression might be associated with disease outcome and could be an indicator for HSCT.

Population Pharmacokinetics of High-Dose Methotrexate in Chinese Pediatric Patients With Acute Lymphoblastic Leukemia.

High-dose methotrexate (HD-MTX) is widely used in pediatric acute lymphoblastic leukemia (ALL) treatment regimens. In this study, we aimed to develop a population pharmacokinetic (PK) model of HD-MTX in Chinese pediatric patients with ALL for designing personalized dosage regimens. In total, 4,517 MTX serum concentration data for 311 pediatric patients with ALL, aged 0.75-15.2 years and under HD-MTX treatment, were retrospectively collected at a tertiary Children's Hospital in China. The non-linear mixed-effect model was used to establish the population PK model, using NONMEM software. The potential covariate effects of age, body weight, and biochemical measurements (renal and liver function) on MTX PK disposition were investigated. The model was then evaluated using goodness-of-fit, visual predictive check. MTX PK disposition was described using a three-compartment model reasonable well. Body weight, implemented as a fixed allometric function on all clearance and volume of distribution parameters, showed a substantial improvement in model fit. The final population model demonstrated that the MTX clearance estimate in a typical child with body weight of 19 kg was 6.9 L/h and the central distribution of volume estimate was 20.7 L. The serum creatinine significantly affected the MTX clearance, with a 0.97% decrease in clearance per 1 µmol/L of serum creatinine. Other covariates (e.g., age, sex, bilirubin, albumin, aspartate transaminase, concomitant medication) did not significantly affect PK properties of MTX. The proposed population PK model could describe the MTX concentration data in Chinese pediatric patients with ALL. This population PK model combined with a maximum a posteriori Bayesian approach could be used to estimate individual PK parameters, and optimize personalized MTX therapy in target patients, thus aiming to reduce toxicity and improve treatment outcomes.

Ras pathway mutation feature in the same individuals at diagnosis and relapse of childhood acute lymphoblastic leukemia.

BACKGROUND: Acute lymphoblastic leukemia (ALL) is the most common malignancy in children, while relapse and refractory ALL remains a leading cause of death in children. However, paired ALL samples of initial diagnosis and relapse subjected to next-generation sequencing (NGS) could construct clonal lineage changes, and help to explore the key issues in the evolutionary process of tumor clones. Therefore, we aim to analyze gene alterations during the initial diagnosis and relapse of ALL patients and to explore the underlying mechanism. METHODS: Targeted exome sequencing technology was used to detect molecular characteristic of initial diagnosis and relapse of ALL in 12 pediatric patients. Clinical features, treatment response, prognostic factors and genetic features were analyzed. RESULTS: In our 12 paired samples, 75% of pre-B-cell acute lymphoblastic leukemia (B-ALL) patients had alterations in the Ras pathway (NRAS, KRAS, NF1, and EPOR), and Ras mutation are very common in patients with ALL relapse. TP53 mutations mainly existed in the primary clones and occurred at the initial diagnosis and relapse of ALL. Relapse-associated genes such as NT5C2 and CREBBP were observed in patients with ALL relapse; however, all patients included in this study had gene abnormalities in the Ras pathway, and NT5C2 and CREBBP genes may collaboratively promote ALL relapse. CONCLUSIONS: Among the 12 ALL patients, Ras pathway mutations are common in ALL relapse and may be associated with other recurrence-related genes alterations. The study with paired samples could improve the understanding of ALL relapse.

Genetic variants and clinical significance of pediatric acute lymphoblastic leukemia.

BACKGROUND: Acute lymphoblastic leukemia (ALL), the most common childhood malignancy, is characterized by molecular aberrations. Recently, genetic profiling has been fully investigated on ALL; however, the interaction between its genetic alterations and clinical features is still unclear. Therefore, we investigated the effects of genetic variants on ALL phenotypes and clinical outcomes. METHODS: Targeted exome sequencing technology was used to detect molecular profiling of 140 Chinese pediatric patients with ALL. Correlation of genetic features and clinical outcomes was analyzed. RESULTS: T-cell ALL (T-ALL) patients had higher initial white blood cell (WBC) count (34.8×109/L), higher incidence of mediastinal mass (26.9%), more relapse (23.1%), and enriched NOTCH1 (23.1%), FBXW7 (23.1%) and PHF6 (11.5%) mutations. Among the 18 recurrently mutated genes, SETD2 and TP53 mutations occurred more in female patients (P=0.041), NOTCH1 and SETD2 mutants were with higher initial WBC counts (≥50×109/L) (P=0.047 and P=0.041), JAK1 mutants were with higher minimal residual disease (MRD) level both on day 19 and day 46 (day 19 MRD ≥1%, P=0.039; day 46 MRD ≥0.01%, P=0.031) after induction chemotherapy. Multivariate analysis revealed that initial WBC counts (≥50×109/L), MLLr, and TP53 mutations were independent risk factors for 3-year relapse free survival (RFS) in ALL. Furthermore, TP53 mutations, age (<1 year or ≥10 years), and MLLr were independently associated with adverse outcome in B-cell ALL (B-ALL). CONCLUSIONS: MLLr and TP53 mutations are powerful predictors for adverse outcome in pediatric B-ALL and ALL. Genetic profiling can contribute to the improvement of prognostication and management in ALL patients.

Circulating MicroRNA-21, MicroRNA-23a, and MicroRNA-125b as Biomarkers for Diagnosis and Prognosis of Burkitt Lymphoma in Children.

BACKGROUND The aim of this study was to investigate the diagnostic and prognostic value of microRNA (miRNA)-21, miRNA-23a, and miRNA-125b in Burkitt lymphoma (BL) in children. MATERIAL AND METHODS We recruited 41 children with BL for the case group, 56 children with lymph node inflammation for the positive control group, and 60 healthy children for the negative control group. Real-time fluorescent quantitative polymerase chain reaction (RT-qPCR) was conducted for detection of circulating miRNA-21, miRNA-23a, and miRNA-125b. A receiver operating characteristic (ROC) curve was drawn to compare the diagnostic value of miRNA-21, miRNA-23a, and miRNA-125b. Kaplan-Meier method and log-rank test were used for prognostic analyses. RESULTS MiRNA-21 and miRNA-23a had significantly higher expression in cases than in positive and negative controls (all P<0.05). Overexpression of miRNA-21 and miRNA-23a were associated with staging, WBC, upregulated serum lactate dehydrogenase (LDH) level, presence of lymphoma size ≥6 cm, and cluster of differentiation 10 (CD10) expression, while miRNA-125b expression had an association with staging and upregulated serum LDH level (both P<0.05). ROC curves of miRNA-21, miRNA-23a, and miRNA-125b presented an area under curve (AUC) of 0.759, 0.853 and 0.615, respectively. MiRNA-21 and miRNA-23a in combination had an AUC of 0.869. After treatment, both miRNA-21 and miRNA-23a expression were significantly decreased (both P<0.05). Advanced clinical stage, upregulated LDH, and lymphoma size of ³6 cm were related to low complete remission rate (all P<0.05). CONCLUSIONS Patients with high expression of miRNA-21 and miRNA-23a had significantly lower complete remission rates and survival rates than those with low expression. Expression of miRNA-21 and miRNA-23a may serve as useful diagnostic and prognostic biomarkers in children with BL.

Association of SLCO1B1 gene polymorphisms with toxicity response of high dose methotrexate chemotherapy in childhood acute lymphoblastic leukemia.

OBJECTIVE: The present study aims to investigate the correlation of polymorphisms of SLCO1B1 gene with the toxicity during therapy with the high-dose methotrexate (MTX) chemotherapy in childhood acute lymphoblastic leukemia. METHODS: We analyzed 2 polymorphisms (rs4149081 and rs11045897) in SLCO1B1 gene in 280 Chinese pediatric B-ALL patients, using MTX plasma concentration as an objective and quantifiable marker of toxicity. We utilized Enzyme-multiplied immunoassay technique (EMIT) to measure the plasma concentration of MTX. The polymerase chain reaction-allele specific (PCR-AS) method was utilized to perform the genotyping. RESULTS: We found there was a statistically significant association between MTX plasma concentration and the SLCO1B1 rs11045879 CC genotype (P<0.05). We also found the rs4149081 AA genotype was associated with high-MTX plasma concentrations. A-C haplotype carriers have a higher risk for MTX delayed clearance but G-T haplotype was associated with a lower risk for MTX delayed clearance. CONCLUSIONS: The rs4149081 AA genotype and the rs11045897 CC genotype could be indicators for high-MTX plasma concentrations in children with ALL.

[Cytogenetic characteristics of 163 children with acute lymphoblastic leukemia].

OBJECTIVE: To further understand the cytogenetic characteristics of pediatric acute lymphoblastic leukemia (ALL). METHODS: Cytogenetic abnormalities of 163 children with newly diagnosed ALL (0-17 years of age) were evaluated by conventional cytogenetic analysis and fluorescent in situ hybridization findings. RESULTS: Chromosome abnormalities were detected in 87.7% of patients (143/163). The ploidy levels most frequently observed among ALL patients were high hyperdiploidy (51-67 chromosomes) (45 cases, 27.6%), Chromosomes X and 21 were gained in 100% of these cases. The most common genetic alterations were t(12;21)/ETV6/RUNX1 (26 cases, 16.0%), followed by t(1;19)/TCF3/PBX1 (13 patients, 8.0%), t(4;11)/MLL rearrangement and t(8;14) IGH/MYC (6 cases, 3.7%), t(9;22)/BCR/ABL(2 cases, 1.2%), and iAMP21 (1 patient, 0.6%). The no-classical structural abnormalities included dup(1q) in 20.2%, del(6q) and del(9p) in 10.4%, del(12p) in 12.9% and del(13q) in 5.5%. The incidences of t(12;21), t(1;19), t(9;22) and high hyperdiploidy were consistent with reports in Western children (P>0.25). The incidence of (9;22) seemed to be much lower in our study than that in Korea (1.5% vs 9.5%, P<0.005). CONCLUSION: Cytogenetic findings of childhood ALL patients are similar to that of Western countries, it seems no more adverse risk factors.

Screening of RB1 gene mutations in Chinese patients with retinoblastoma and preliminary exploration of genotype-phenotype correlations.

PURPOSE: Retinoblastoma (RB) sets the paradigm for hereditary cancer syndromes, for which medical care can change depending on the results of genetic testing. In this study, we screened constitutional mutations in the RB1 gene via a method combining DNA sequencing and multiplex ligation-dependent probe amplification (MLPA), and performed a preliminary exploration of genotype-phenotype correlations. METHODS: The peripheral blood of 85 retinoblastoma probands, including 39 bilateral and 46 unilateral, was collected, and genomic DNA was extracted. DNA sequencing was conducted first. MLPA analysis was applied for patients with bilateral RB with negative sequencing results and unilateral probands whose age at diagnosis was less than 1 year old. RESULTS: Thirty-four distinct mutations were identified in 40 (47.1%) of the 85 probands (36 bilateral and four unilateral), of which 20% (8/40) was identified by MLPA. The total detection rate in bilateral cases was 92.3% (36/39). Of the total mutations identified, 77.5% (31/40) probands with a mean age of 10.7 months at diagnosis had null mutations, and 22.5% (9/40) with a mean age of 13.5 months at diagnosis had in-frame mutations. Of the 31 probands with null mutations, bilateral RB accounted for 96.8% (30/31). Of the nine probands with in-frame mutations, 66.7% had bilateral RB. There were seven new mutations of RB1 identified in this report, including six null mutations and one missense mutation. Clinical staging of the tumor did not show obvious differences between patients with null mutations and in-frame mutations. CONCLUSIONS: Our results confirm that the type of mutation is related to age of onset and the laterality, but not staging of the retinoblastoma tumor. MLPA is a reliable method for detecting gross deletion or duplication of the RB1 gene. The combination of sequencing and MLPA improves the clinical diagnosis of RB.

Clinical outcome of childhood lymphoblastic lymphoma in Shanghai China 2001-2010.

BACKGROUND: This retrospective cohort study analysed the clinical characteristics and outcomes of patients with childhood lymphoblastic lymphoma (LBL) treated in Shanghai, China. PROCEDURE: From 2001 to 2010, 108 evaluable patients ≤16 years of age who were newly diagnosed with biopsy-proven LBL were treated with one of three treatment protocols: CCCG-99, SCMC-T-NHL-2002, or LBL-CHOF-2006. RESULTS: Two patients had Stage I disease, 5 had Stage II, 55 had Stage III, and 46 had Stage IV. The immunophenotype was T-cell LBL in 92 patients (85.2%) and precursor B-cell LBL in 16 (14.8%). The abandonment rate was 11.5%. Twenty-five patients (23.2%) suffered from resistant disease, including 1 with isolated central nervous system (CNS) relapse. At a median follow-up of 40.4 months (range, 0-114 months), the 5-year probability of event-free survival (pEFS) was 63.9 ± 4.6% in all patients. The 5-year pEFS for patients with pB-LBL was better than for patients with T-LBL (100% vs. 61.3 ± 5.1%, P = 0.007). Patients who had achieved complete remission on day 33 of induction had significantly better pEFS than those who had not (78.8 ± 4.6% vs. 28.2 ± 9.0%, P = 0.000). Three of 25 patients who experienced resistant disease were alive at the end of the study period. CONCLUSIONS: The abandonment rate was lower for patients with LBL than for patients with acute lymphoblastic leukemia. Prophylactic cranial radiation can be omitted for patients with LBL even when advanced-stage disease is present, as intensive systemic chemotherapy with intrathecal therapy is sufficient to prevent CNS relapse. The survival of patients with resistant disease was very poor.

Improved outcome for children with non-high risk acute lymphoblastic leukaemia after using an ALL IC-BFM 2002-based protocol in Shanghai, China.

We report the outcome of 92 non-high risk children with acute lymphoblastic leukaemia (ALL) following a Berlin-Frankfürt-Münster (BFM) Intercontinental ALL -based protocol. Compared with a matched historical control group, we found a lower incidence of treatment-related early death (1·2% vs. 10·9%, P = 0·015), a higher 6-year event-free survival (75·4 ± 4·9% vs. 58·2 ± 6·7%, P = 0·02), reduced total in-hospital costs per person (US $) (10267·0 vs. 18331·0, P < 0·001) and fewer total in-hospital days (164 vs. 296, P < 0·001). This ALL-BFM based protocol was quite tolerable in our institution and will be extended to high-risk patients.

[Clinical characteristics of hepatic veno-occlusive disease in 6 children with hematologic neoplasm treated with 6-thioguanine].

OBJECTIVE: To improve the treatment of drug related childhood hepatic veno-occlusive disease (HVOD), clinical characteristics of 6 children with hematologic neoplasm from 2 hospitals of China Children's Leukemia Group (CCLG) treated with 6-thioguanine (6-TG) complicated with HVOD were analyzed. METHOD: All the drug related HVOD patients were treated with CCLG acute lymphoblastic leukemia (ALL)-2008 protocol. They were from Children's Hospital of Fudan University and Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College from April 2008 to April 2009. The diagnosis was made according to the modified Seattle criteria and Baltimore criteria, including 2 or 3 of the following clinical features: hepatomegaly and upper right abdominal pain, jaundice (bilirubin ≥ 35 µmol/L), ascites or confirmed by pathology. The 6 HVOD patients' clinical manifestations, laboratory finding, imageologic and pathologic data were collected and analyzed. RESULT: Of the 6 patients, 2 were males and 4 females. Mean age of the 6 patients was 3.89 years (range from 3 years 1 month to 4 years 11 months). The original disease was acute lymphoblastic leukemia. HVOD occurred during chemotherapy protocols of CAM (CTX + Ara-C + 6-TG) or maintenance period (MTX + 6-TG). Most of 6 HVOD patients presented with pain in liver area, hepatomegaly on imaging, elevated aminotransferase and bilirubin (often ≥ 35 µmol/L), hydroperitonia was common, one with pleural fluid, illegible hepatic veins. All the patients recovered after being treated with hepatoprotective, jaundice-relieving and supportive therapeutics, some patients were treated with low molecular weight heparin. The prognoses were good. CONCLUSION: HVOD was a serious complication of chemotherapy with 6-TG. Hepatoprotective and jaundice-relieving and low molecular weight heparin could improve the prognosis.