6-巯基嘌呤致急性淋巴细胞白血病患儿不良反应及其与TPMT基因多态性的关系

目的 分析6-巯基嘌呤（6-MP）维持治疗急性淋巴细胞白血病（ALL）患儿不良反应的发生情况,探讨巯嘌呤甲基转移酶（TPMT）基因多态性与6-MP毒副作用的关系。方法 提取46例ALL患儿骨髓细胞总RNA并逆转录成cDNA。应用变性梯度凝胶电泳（DGGE）结合DNA测序,对ALL患儿TPMT*S和*3C基因型进行检测。采用美国国立癌症研究所第3版常规毒性判定标准（NCI CTC 3.0）行药物毒性分级,分析TPMT基因多态性与6-MP不良反应发生的关系。结果 在维持治疗阶段,22%（10/46）患儿因6-MP所致严重不良反应停药,不良反应主要表现为骨髓抑制、肝脏毒性和胃肠道反应。2例TPMT*3C突变基因型（AG+GG）患儿均出现重度不良反应,其中1例纯和突变患儿出现与6-MP剂量相关的骨髓抑制和肝脏毒性。TPMT*1S各基因型与6-MP所致的重度骨髓抑制及肝脏毒性无明显相关性（P>0.05）。结论 TPMT*3C多态性可能与6-MP所致严重不良反应发生有关。     

Cytomegalovirus disease in children with acute lymphoblastic leukemia

Viral infections are an underrecognized problem in children on standard chemotherapy for acute lymphoblastic leukemia (ALL). In countries with high baseline seroprevalence of cytomegalovirus (CMV) such as India, it may be an important pathogen leading to fever, end-organ damage, and cytopenia. Data regarding the incidence and manifestations of CMV disease in pediatric ALL patients are scanty. The authors prospectively assessed all children on chemotherapy for ALL with prolonged febrile neutropenia (FN) for CMV disease over a 3-year period. Children with end-organ damage, including pneumonia, retinitis, and colitis, were also evaluated. Quantitative and qualitative polymerase chain reaction (PCR) from blood, body fluids, or tissue was done along with ophthalmologic evaluation. CMV disease was detected in 10% of the children with prolonged FN. In addition, other children were identified due to end-organ damage, lung and eye being the common organs of involvement. Time of CMV reactivation was essentially during nonintense phase of chemotherapy. Lymphopenia was present in most children, and prolonged lymphopenia was associated with relapse of CMV infection after therapy. The authors conclude that CMV is an important pathogen in children on standard chemotherapy for ALL. It has a good outcome with early detection and directed therapy. Parenteral ganciclovir is needed for a period of 14–21 days to prevent recurrence.     

Vincristine disposition in children with acute lymphoblastic leukemia

Vincristine (VCR) has been widely used to treat childhood malignancies for over thirty years, but its plasma disposition has not yet been well-defined. Therefore, we conducted a pharmacokinetic study of VCR in 17 children with acute lymphoblastic leukemia (ALL) receiving the first dose of VCR. A new high-performance liquid chromatographic assay was used for the measurement of VCR in plasma. A two-compartment pharmacokinetic model was fit to the data by nonlinear least-squares regression. Estimated pharmacokinetic parameters were highly variable; mean (S.D.) volume of distribution at steady-state was 360 (176) L.m^?2; total body clearance was 431 (238) ml. min^?1.m^?2, and elimination half-life was 823 (390) min. These results were compared to data from eight adults with lung cancer. Mean volume of distribution in adults and children were similar, but VCR clearance was significantly larger in children (P = 0.01), resulting in a significantly longer elimination half-life in the adults (P < 0.01). We conclude that administration of a standard dosage of VCR to children with ALL results in a highly variable systemic drug exposure, which may have implications for the oncolytic effect and/or toxicity in individual patients. Comparison of data from children and adults suggests that VCR elimination rate is a function of age; this could account for more severe neurotoxicity in older patients. However, it cannot be excluded that differences between the children and adults may be due to other variables than age. Future studies should focus on the possible influence of multidrug resistance modulating agents on VCR pharmacokinetics and on pharmacokinetic-pharmacodynamic relationships in individual patients. © 1995 Wi1ey-Liss Inc.     

Neutropenic enterocolitis in children with acute lymphoblastic leukemia

Neutropenic enterocolitis is an acute, life-threatening inflammation of the small and large bowel, often seen in children with malignancies during periods of prolonged or severe neutropenia. During the period 1990-1995, 180 children were treated at the authors' center for acute lymphoblastic leukemia using a standard chemotherapy protocol. Among them, 11 children (6.1%) aged 4 to 12 years, were diagnosed clinically to have neutropenic enterocolitis. Eight had severe neutropenia (absolute neutrophil count < 10(8)/L and 5 had prolonged neutropenia (> 7 days duration). The symptoms included diffuse abdominal pain (10 children), oral mucositis (7), hematochezia (7), diarrhea (6), hematemesis (5), and right lower quadrant tenderness (4). Three children had radiological evidence of free intraperitoneal gas and an additional 3 children were found on surgical exploration to have cecal perforation. Laparotomy was performed on 8 children (73%), 4 of whom survived. Among the 3 children managed conservatively, 1 died awaiting surgical exploration, while the other 2 did well. The overall survival was 55%. The authors recommend an approach to management that respects the heterogeneity of the disease.     

Human bocavirus in children with acute lymphoblastic leukemia

A new human parvovirus, human bocavirus, has recently been identified in respiratory secretions, feces and serum. It is associated with lower and most likely also upper respiratory tract infections. Most commonly reported symptoms are cough, rhinorrhea, expiratory wheezing and fever, and the virus is preferentially detected in young children. We report three children with acute lymphoblastic leukemia who had acute febrile episodes with concomitant detection of human bocavirus in their respiratory secretions. One of them had five consecutive febrile episodes during 6 months, all associated with the presence of human bocavirus at varying viral loads, suggesting prolonged shedding or reactivation of the virus.     

XYY syndrome in children with acute lymphoblastic leukemia

Certain constitutional chromosomal abnormalities increase the risk of malignancy and/or decrease treatment tolerance. We identified two patients with the XYY syndrome among a total of 444 male children with acute lymphoblastic leukemia who had complete cytogenetics studies. In both cases, the leukemic cell karyotype suggested a constitutional XYY abnormality that was confirmed in studies of lymphocytes obtained during remission. The incidence rate in our series is higher than that of the XYY syndrome in the general population (0.0045 vs. 0.001), but not significantly so. This finding and a literature review failed to confirm an increased frequency of the XYY syndrome among children with acute lymphoblastic leukemia. Both of our patients remain in remission 24 and 28 months, respectively, postdiagnosis. Their tolerance of intensive treatment, including high-dose methotrexate, suggests that the untoward treatment toxicity seen in patients with chromosomal abnormalities such as trisomy 21 does not extend to the XYY syndrome. © 1997 Wiley-Liss, Inc.     

Desensitization to pegaspargase in children with acute lymphoblastic leukemia and lymphoblastic lymphoma

Hypersensitivity to pegaspargase is associated with inferior survival in pediatric patients with acute lymphoblastic leukemia and lymphoblastic lymphoma. In the past year, drug‐supply shortages have led to the lack of an available alternative to pegaspargase. Rather than omit asparaginase from the treatment of acute lymphoblastic leukemia or lymphoblastic lymphoma patients with hypersensitivity to pegaspargase, we continued pegaspargase treatments for nine pediatric patients, utilizing a rapid desensitization protocol. There were no adverse events related to the pegaspargase during desensitization, and all patients who were checked had asparaginase serum levels above the threshold of 0.1 IU/mL at 7 to 14 days after pegaspargase therapy.     

Acquired X-chromosome aneuploidy in children with acute lymphoblastic leukemia

BACKGROUND: A cytogenetic study of 75 consecutive children with ALL revealed a normal karyotype, a low hyperdiploid karyotype (including 47-50 chromosomes), and a high hyperdiploid karyotype (including > 50 chromosomes) in 10, 12, and 33 patients, respectively. An acquired extra X-chromosome was detected at diagnosis by conventional cytogenetics in 29 (88%) of 33 children with a high hyperdiploid karyotype and in 4 (33%) of 12 children with a low hyperdiploid karyotype. X-chromosome aneuploidy was retrospectively studied by fluorescence in situ hybridization (FISH) in eight and 20 patients with a normal and a hyperdiploid karyotype, respectively. PROCEDURE: A classical cytogenetic study was performed according to standard methods. FISH with the centromeric probe specific to X-chromosome was used to study interphase cells of bone marrow or blood samples. RESULTS: An extra X-chromosome was found by FISH in all 13 patients with a high hyperdiploid or tetraploid, in 6 of 7 patients with a low hyperdiploid, and in none with a normal karyotype. Two children with a normal karyotype displayed monosomy X. Altogether, 57.3% of newly diagnosed children displayed X-chromosome aneuploidy. CONCLUSIONS: Out study indicates that X-chromosome aneuploidy may be the most common chromosome abnormality in childhood ALL. It can be detected in nearly all children with a high hyperdiploid karyotype and up to one-half of the patients with a low hyperdiploid karyotype. FISH with an X-chromosome centromeric probe is a rapid and simple tool to detect an abnormal clone at diagnosis in the majority of children with ALL and is useful in confirming remission in these patients.     

Predictable risk factors in children with acute lymphoblastic leukemia

The predictable prognostic factors were analysed among 174 children with acute lymphoblastic leukemia who were treated during the last ten years under different protocols in one institute. It was confirmed that the children under 1 year of age, or with T-cell marker, had poor prognosis. The initial WBC of more than 50,000/mm3 was less significant as a predictable risk factor with chemotherapy of the newer protocols. Cell kinetic study was found to be of no more help than the initial WBC, but a more accurate prediction could be obtained by measuring glucocorticoid receptor of leukemic cells. The prognosis was poor among children with initial WBC of more than 50,000/mm3 and receptors of less than 20,000 sites per cell.     

Transient hyperglycemia in Hispanic children with acute lymphoblastic leukemia

BACKGROUND: Transient hyperglycemia occurs commonly during the treatment for childhood acute lymphoblastic leukemia (ALL). The purpose of this study was to examine the incidence of and risk factors for transient hyperglycemia during induction chemotherapy in Hispanic pediatric patients diagnosed with B-Precursor ALL. PROCEDURE: The study cohort consisted of 155 Hispanic pediatric patients diagnosed with ALL and treated at one of two South Texas pediatric oncology centers between 1993 and 2002. Hyperglycemia was defined as > or = 2 glucose determinations of > or = 200 mg/dl during the first 28 days of induction chemotherapy. RESULTS: Overall, 11.0% of the study cohort developed transient hyperglycemia during induction chemotherapy. Age and body mass index (BMI) were both positively associated with the risk of hyperglycemia. Females exhibited a substantially higher risk of hyperglycemia than males, but this association did not reach statistical significance after adjusting for other covariates. Among patients who developed hyperglycemia, 100% of those who required insulin were in the 13-18-year age group and reported a family history of diabetes. Hyperglycemic patients classified as obese (BMI > or = 95 centile) were more than twice as likely to have required insulin therapy compared to overweight patients (BMI 85-<95 centile) and three times as likely to have required insulin compared to normal weight (BMI < 85 centile) patients. CONCLUSIONS: The incidence of chemotherapy-induced transient hyperglycemia in the present study cohort is comparable to that reported in previous pediatric ALL patients. This finding is interesting in view of the elevated prevalence of obesity and the underlying dietary behaviors in this Hispanic study cohort.     

Strength and functional mobility in children with acute lymphoblastic leukemia

BACKGROUND: The purposes of this pilot study were as follows: (1) to evaluate tools for measuring neuropathy in children with acute lymphoblastic leukemia (ALL), (2) to examine strength and functional mobility in children with ALL, and (3) to determine if there is a relationship between strength and function. PROCEDURE: Strength of knee extension and ankle dorsiflexion as measured with a dynamometer and functional mobility with the Timed Up and Go (TUG) were examined in eight children with ALL, ages 4-15 years, before and during delayed intensification (DI) therapy and in age- and gender-matched controls. RESULTS: The mean knee extension strength, ankle dorsiflexion strength, and TUG measures for children with ALL before DI were significantly less than the means for the controls. The mean dorsiflexion strength measures for the children with ALL after 4 weeks of DI therapy were significantly lower than at time zero. Correlation of -0.794 (P = 0.05) was found between knee extension strength and TUG score for children with ALL. CONCLUSIONS: The dynamometer and TUG are reliable tools to measure strength and function in children with ALL early in their treatment. In this study, ankle dorsiflexion strength worsened during DI therapy. There was a correlation between strength and function in children with ALL.     

Trimethoprim-sulfamethoxazole and nystatin prophylaxis in children with acute lymphoblastic leukemia

In 1980 we began a prospective randomized trial of trimethoprim-sulfamethoxazole (TMPSMZ)gnd nystatin prophylaxis in children with acute lymphoblastic leukemia during remission induction therapy. The study was planned (1) to determine the efficacy of this combination in reducing the incidence of fever, infection, and hospitalization, (2) to assess the hematologic toxicity in these patients, and (3) to evaluate the method of randomization proposed by Zelen to expedite clinical studies. Sixty-seven patients were eligible; 30 were randomized by birth date to receive prophylaxis; 37 were randomized to receive no prophylayis (control group). Sixty patients received appropriate therapy and were fully evaluabll-. Eight episodes of infection and seven fevers of unknown origin occurred in the control group; two documented infections and three fevers of unknown origin occurred in the group receiving prophylaxis (p = 0.06). The control group spent 139 of 642 neutropenic days in the hospital; the prophylaxis group spent 39 of 462 neutropenic days in the hospital (p < 0.001). Significant differences in mean neutrophil counts (846 vs. 514) were found in the two groups only at day 14. The method of randomization did expedite enrollment in the study but introduced a bias by allowing for refusals in the prophylaxis group only. We conclude that TMP-SMZ and nystatin prophylaxis benefits this group of patients because of the reduction in hospitalization, but because of potential myelosuppression and changing chemotherapeutic induction regimens, studies with larger numbers of homogeneous groups of patients are needed before routine prophylaxis can be recommended for all patients with this disease.     

Acute respiratory illness in children with acute lymphoblastic leukemia

Ten of 70 children (14%) with acute lymphoblastic leukemia developed severe interstitial pneumonitis within three weeks after induction of central nervous system prophylactic therapy. The clinical picture was characterized by fever, cough, progressive dyspnea, and hypoxemia with complete resolution in one to three weeks, except in one patient who died during the acute illness from respiratory failure. P. carinii organisms were found in the lung tissue of only one patient. The etiology of the pneumonitis in the other nine children was probably viral, acquired or activated during a period of lymphopenia and immunosuppression. The morbidity and potential mortality from the pneumonitis warrants early recognition by open lung biopsy and intensive supportive therapy.     

Thiopurine methyltransferase deficiency in childhood lymphoblastic leukaemia: 6-mercaptopurine dosage strategies

Daily 6-mercaptopurine (6MP) forms the backbone of continuing chemotherapy for childhood lymphoblastic leukaemia (ALL). A major metabolic route is catalysed by thiopurine methyltransferase (TPMT). TPMT deficiency occurs in 1 in 300 individuals and results in high concentrations of thioguanine nucleotides (TGNs), cytotoxic 6MP metabolites. A leukaemic child taking 6MP repeatedly developed profound pancytopenias. TPMT deficiency was confirmed. TGN formation was then studied on attenuated 6MP dosages. Four weekly oral doses of 75 mg/m² 6MP produced TGNs of 2348 pmol/8 × 10⁸ red cells, nearly double the maximum TGNs recorded in ALL children with TPMT activity taking long term daily 75 mg/m² 6MP. Grossly elevated TGN concentrations were also produced at 10% standard 6MP dosage (7.5 mg/m² daily), accompanied by unacceptable 6MP toxicity (neutropenia, diarrhoea, vomiting). The child was eventually stabilised on 10% alternate day therapy and after 15 weeks TGNs were 1670 pmol, just above the upper end of the TGN range for ALL children with TPMT activity. Med. Pediatr. Oncol. 29:252–255, 1997. © 1997 Wiley-Liss, Inc.