Immunophenotype of lymphocytes and real-world outcome of COVID-19 infection in children with hematology and oncology.

BACKGROUND: Patients with immunocompromise were suspected to encounter a high risk for severe coronavirus disease 2019 (COVID-19) infection on early period; however, data is lacking nowadays and immune response remain unclear. METHODS: In this retrospective study, internet questionnaire survey and medical records were acquired in pediatric hematology oncology patients. Clinical severity, immunological characteristics, and outcomes were analyzed from December 1, 2022 to January 31, 2023 at the 3rd year of pandemic in China. RESULTS: A total of 306 patients were included, with 21 patients (6.9%) asymptomatic, 262 (85.6%) mild severity, 17 (5.6%) moderate severity, 5 (1.6%) severe severity, and 1 (0.3%) critical severity. Seventy-eight (25.5%) patients were on intensive chemotherapy, and 32.0% children were on maintenance chemotherapy. Delays in cancer therapy occurred in 86.7% patients. Univariable analysis revealed active chemotherapy (P < 0.0001), long duration of symptom (P < 0.0001), low lymphocytes count (P = 0.095), low CD3 + and CD8 + T cell count (P = 0.013, P = 0.022), high percentage of CD4 + TCM (P = 0.016), and low percentage of transitional B cells (P = 0.045) were high risk factors for severe COVID-19 infection. Cox regression model showed that the absolute lymphocytes count (P = 0.027) and long duration of symptom (P = 0.002) were the independent factors for severity. Patients with CD8 + dominant and B cell depletion subtype wasn't related with severity, but had higher percentage of CD8 + effector memory T cells (TEM) and terminally differentiated effector memory T cells (TEMRA) (P < 0.001, P < 0.001), and a longer COVID-19 duration (P = 0.045). CONCLUSION: The severity was relatively mild in children with immunodeficiencies in the third year of COVID-19 pandemic. Low lymphocyte count and long duration of symptom were the independent risk factors with COVID-19 severity. Delays in cancer care remain a major concern and the long outcome is pending.

Extracranial Germ Cell Tumors in Children: Ten Years of Experience in Three Children's Medical Centers in Shanghai.

OBJECTIVE: The aim was to describe the clinical features of extracranial germ cell tumors (GCTs) in pediatrics and study the clinical risk factors related to survival for malignant germ cell tumors (MGCTs) in order to optimize therapeutic options. METHODS: The clinical data of children with extracranial GCTs in three children's medical centers in Shanghai were retrospectively analyzed. RESULTS: In total, 1007 cases of extracranial GCTs diagnosed between 2010 and 2019 were included in this study, including teratomas (TERs) 706 (70.11%) and MGCTs 301 (29.89%). There were twice as many TER cases as MGCT cases. Approximately 50% of children with GCTs were <3 years old (43.39% for TERs, 67.13% for MGCTs). GCTs in children of different ages show differences in tumor anatomical locations and pathological subtypes. The 5-year event-free survival (EFS) and overall survival (OS) of all patients with MGCTs were 82.33% (95% CI, 77.32%, 86.62%) and 94.13% (95% CI, 90.02%, 96.69%), respectively. The multivariate Cox regression analysis identified a primary site in the mediastinum and alpha fetoprotein (AFP) levels ≥10,000 ng/mL as independent adverse prognostic factors (p < 0.0.0001, χ2 = 23.6638, p = 0.0225, χ2 = 5.2072.). There were no significant differences in OS among children receiving various chemotherapy regimens, such as the BEP, PEB, JEB and other regimens (VBP/VIP and AVCP/IEV) (p < 0.05). CONCLUSIONS: The clinical features of GCTs in Chinese pediatrics are similar to those reported in children in Europe and America. The age distribution of pathological types and primary sites in GCTs reflect the developmental origin of type I and type II GCTs transformed from mismigration primordial germ cells (PGCs). Optimizing the current platinum-based chemotherapy regimens and exploring the treatment strategies for MGCTs of the mediastinum are future research directions.

A multicenter prospective study on the management of hepatoblastoma in children: a report from the Chinese Children's Cancer Group.

BACKGROUND: This study aimed to identify survival risk factors in Chinese children with hepatoblastoma (HB) and assess the effectiveness of the new treatment protocol proposed by the Chinese Children's Cancer Group (CCCG) in 2016. METHODS: A multicenter, prospective study that included 399 patients with HB from January 2015 to June 2020 was conducted. Patient demographics, treatment protocols, and other related information were collected. Cox regression models and Kaplan-Meier curve methods were used. RESULTS: The 4-year event-free survival (EFS) and overall survival (OS) were 76.9 and 93.5%, respectively. The 4-year EFS rates for the very-low-risk, low-risk, intermediate-risk, and high-risk groups were 100%, 91.6%, 81.7%, and 51.0%, respectively. The 4-year OS was 100%, 97.3%, 94.4%, and 86.8%, respectively. Cox regression analysis found that age, tumor rupture (R +), and extrahepatic tumor extension (E +) were independent prognostic factors. A total of 299 patients had complete remission, and 19 relapsed. Patients with declining alpha-fetoprotein (AFP) > 75% after the first two cycles of neoadjuvant chemotherapy had a better EFS and OS than those ≤ 75%. CONCLUSIONS: The survival outcome of HB children has dramatically improved since the implementation of CCCG-HB-2016 therapy. Age ≥ 8 years, R + , and E + were independent risk factors for prognosis. Patients with a declining AFP > 75% after the first two cycles of neoadjuvant chemotherapy had better EFS and OS.

Targeted next-generation sequencing identifies a novel nonsense mutation in ANK1 for hereditary spherocytosis: A case report.

BACKGROUND: Hereditary spherocytosis (HS) is characterized by anemia, jaundice, splenomegaly, and cholelithiasis, and is caused by abnormal genes encoding red blood cell membrane components. The most common mutations found in HS are in the ANK1 gene. CASE SUMMARY: A 4-mo-old girl was admitted to our hospital with pallor that had lasted for more than 2 mo. She presented with jaundice, anemia and splenomegaly. A heterozygous mutation of ANK1 (exon23: c.G2467T:p.E823X) was identified, and the mutation was determined to be autosomal dominant. This mutation is linked to the relatively serious anemia she had after birth; this anemia improved with age. CONCLUSION: The utilization of next-generation sequencing may assist with the accurate diagnosis of HS, especially in atypical cases.

First report of successful treatment for hemoglobin Bristol-Alesha by hemopoietic stem cell transplantation.

HBB gene mutations lead to many kinds of diseases, of which, except for the two most common diseases of thalassemia and sickle cell anemia, rare kinds of hemolytic anemia, such as hemoglobin Bristol-Alesha, are rarely reported, no ideal treatment in clinic. A child suffered from chronic recurrent hemolytic attacks and the related genes of hereditary hemolytic anemia were detected on her. Hematopoietic stem cell transplantation was conducted in the treatment of the patient. The patient was diagnosed as hemoglobin Bristol-Alesha and achieved complete recovery after hematopoietic stem cell transplantation. For Bristol-Alesha, without characteristic clinical manifestation and specific biochemical examination, diagnosis is dependent on the gene mutation detection and hematopoietic stem cell transplantation is an effective and curable method.

Bone and bone marrow involvement in neuroblastoma: A case report.

RATIONALE: Neuroblastoma (NB) can occur in any part of the sympathetic nervous system, and it is highly heterogeneous. Tumors that only involve bone marrow and bone lesions without solid masses have rarely been reported. PATIENT CONCERNS: A 2-year-old girl child presented with recurrent fever, accompanied by pain in both lower limbs for more than 1 month. DIAGNOSE: Bone marrow examination revealed NB cell invasion. Femoral and multiple vertebral lesions were observed by MRI, while head MRI, chest CT, abdominal CT, and pelvic CT showed no solid mass. INTERVENTIONS: The child received the standard therapy for high-risk NB. OUTCOMES: She was sensitive to the initial chemotherapy protocol. Two years later, a bone marrow examination confirmed NB recurrence. LESSONS: The prognosis of this special type of NB was not improved mainly based on common chemotherapy and local radiotherapy, and new treatment strategies should be explored.

Therapeutic potential of targeting MYCN: A case series report of neuroblastoma with MYCN amplification.

INTRODUCTION: Neuroblastoma (NB) with MYCN amplification has a poor prognosis and high mortality. The potential molecular biological relationship between clinical features and MYCN amplification should be explored. METHODS: NB patients were examined by fluorescence in situ hybridization (FISH) for MYCN amplification in the tumor mass or bone marrow samples to determine whether MYCN was amplified. A series of eleven MYCN-amplified NB patients were included. The age, primary site, tumor size, specific biomarkers, and invaded organs were analyzed. All patients accepted standardized treatment of surgery, chemotherapy, and radiotherapy. Progression-free survival (PFS) and overall survival (OS) were evaluated. RESULTS: The median age at diagnosis was 24 months. Nine patients (81.8%) were in stage IV, with high serum neuron-specific enolase (NSE) expression, normal urine vanillylmandelic acid (VMA) level and extensive metastases. All patients accepted a chemotherapy protocol with 8 to 10 cycles, and 9 patients (81.8%) were sensitive to the initial chemotherapy protocol. At the end of follow-up, four patients (36.3%) died with a median OS of 15 months. Five patients (45%) survived with a median PFS of 13 months. Two patients were still receiving chemotherapy. CONCLUSION: Given the effect of MYCN amplification on poor outcome in NB, novel treatments targeting MYCN should be developed for patients with NB.

Sam68 impedes the recovery of arterial injury by augmenting inflammatory response.

OBJECTIVE: The role of Src-associated-in-mitosis-68-kDa (Sam68) in cardiovascular biology has not been studied. A recent report suggests that Sam68 promotes TNF-α-induced NF-κB activation in fibroblasts. Here we sought to dissect the molecular mechanism by which Sam68 regulates NF-κB signaling and its functional significance in vascular injury. APPROACH AND RESULTS: The endothelial denudation injury was induced in the carotid artery of Sam68-null (Sam68-/-) and WT mice. Sam68-/- mice displayed an accelerated re-endothelialization and attenuated neointima hyperplasia, which was associated with a reduced macrophage infiltration and lowered expression of pro-inflammatory cytokines in the injured vessels. Remarkably, the ameliorated vascular remodeling was recapitulated in WT mice after receiving transplantation of bone marrow (BM) from Sam68-/- mice, suggesting the effect was attributable to BM-derived inflammatory cells. In cultured Raw264.7 macrophages, knockdown of Sam68 resulted in a significant reduction in the TNF-α-induced expression of TNF-α, IL-1ß, and IL-6 and in the level of nuclear phospho-p65, indicating attenuated NF-κB activation; and these results were confirmed in peritoneal and BM-derived macrophages of Sam68-/- vs. WT mice. Furthermore, co-immunoprecipitation and mass-spectrometry identified Filamin A (FLNA) as a novel Sam68-interacting protein upon TNF-α treatment. Loss- and gain-of-function experiments suggest that Sam68 and FLNA are mutually dependent for NF-κB activation and pro-inflammatory cytokine expression, and that the N-terminus of Sam68 is required for TRAF2-FLNA interaction. CONCLUSIONS: Sam68 promotes pro-inflammatory response in injured arteries and impedes recovery by interacting with FLNA to stabilize TRAF2 on the cytoskeleton and consequently potentiate NF-κB signaling.

Pax4 synergistically acts with Pdx1, Ngn3 and MafA to induce HuMSCs to differentiate into functional pancreatic ß-cells.

It has been indicated that the combination of pancreatic and duodenal homeobox 1 (Pdx1), MAF bZIP transcription factor A (MafA) and neurogenin 3 (Ngn3) was able to reprogram various cell types towards pancreatic ß-like cells (pßLCs). Paired box 4 (Pax4), a transcription factor, has a key role in regulating the maturation of pancreatic ß-cells (pßCs). In the present study, it was investigated whether Pax4 is able to synergistically act with Pdx1, Ngn3 and MafA to induce human umbilical cord mesenchymal stem cells (HuMSCs) to differentiate into functional pßCs in vitro. HuMSCs were isolated, cultured and separately transfected with adenovirus (Ad) expressing enhanced green fluorescence protein, Pax4 (Ad-Pax4), Pdx1+MafA+Ngn3 (Ad-3F) or Ad-Pxa4 + Ad-3F. The expression of C-peptide, insulin and glucagon was detected by immunofluorescence. The transcription of a panel of genes was determined by reverse transcription-quantitative PCR, including glucagon (GCG), insulin (INS), NK6 homeobox 1 (NKX6-1), solute carrier family 2 member 2 (SLC2A2), glucokinase (GCK), proprotein convertase subtilisin/kexin type 1 (PCSK1), neuronal differentiation 1 (NEUROD1), ISL LIM homeobox 1 (ISL 1), Pax6 and PCSK type 2 (PCSK2). Insulin secretion stimulated by glucose was determined using ELISA. The results suggested that, compared with Ad-3F alone, cells co-transfected with Ad-Pax4 and Ad-3F expressed higher levels of INS and C-peptide, as well as genes expressed in pancreatic ß precursor cells, and secreted more insulin in response to high glucose. Furthermore, the expression of GCG in cells transfected with Ad-3F was depressed by Ad-Pax4. The present study demonstrated that Pax4 was able to synergistically act with the transcription factors Pdx1, Ngn3 and MafA to convert HuMSCs to functional pßLCs. HuMSCs may be potential seed cells for generating functional pßLCs in the therapy of diabetes.

Two novel ANK1 loss-of-function mutations in Chinese families with hereditary spherocytosis.

Hereditary spherocytosis (HS) is the most common inherited haemolytic anaemia disorder. ANK1 mutations account for most HS cases, but pathogenicity analysis and functional research have not been widely performed for these mutations. In this study, in order to confirm diagnosis, gene mutation was screened in two unrelated Chinese families with HS by a next-generation sequencing (NGS) panel and then confirmed by Sanger sequencing. Two novel heterozygous mutations (c.C841T, p.R281X and c.T290G, p.L97R) of the ANK1 gene were identified in the two families respectively. Then, the pathogenicity of the two new mutations and two previously reported ANK1 mutations (c.C648G, p.Y216X and c.G424T, p.E142X) were studied by in vitro experiments. The four mutations increased the osmotic fragility of cells, reduced the stabilities of ANK1 proteins and prevented the protein from localizing to the plasma membrane and interacting with SPTB and SLC4A1. We classified these four mutations into disease-causing mutations for HS. Thus, conducting the same mutation test and providing genetic counselling for the two families were meaningful and significant. Moreover, the identification of two novel mutations enriches the ANK1 mutation database, especially in China.

Epigenetic regulation of megakaryocytic and erythroid differentiation by PHF2 histone demethylase.

Plant homeodomain finger 2 (PHF2) is a JmjC family histone demethylase that demethylates H3K9me2, a repressive gene marker. PHF2 was found to play a role in the differentiation of several tissue types such as osteoblast and adipocyte differentiation. We report here that PHF2 plays a role in the epigenetic regulation of megakaryocytic (MK) and erythroid differentiation. We investigated PHF2 expression during MK and erythroid differentiation in K562 and human CD34+ progenitor (hCD34+ ) cells. Our data demonstrate that PHF2 expression is down-regulated during megakaryopoiesis and erythropoiesis. PHF2 has a negative role in MK and erythroid differentiation of K562 cells; knockdown of PHF2 promotes MK and erythroid differentiation of hCD34+ cells. Similarly, we found that p53 expression is also down-regulated during MK and erythroid differentiation, which parallels PHF2 expression. PHF2 binds to the p53 promoter and regulates the expression of p53 by demethylating H3K9me2 in the promoter region of p53. Taken together, our data show that PHF2 is a negative epigenetic regulator of MK and erythroid differentiation, and that one of the pathways through which PHF2 affects MK and erythroid differentiation is via regulation of p53 expression.

A Novel Functional Missense Mutation p.T219A in Type 1 Gaucher's Disease.

BACKGROUND: Gaucher's disease (GD) is an autosomal recessive disorder caused by a deficiency of acid ß-glucosidase (glucocerebrosidase [GBA]) that results in the accumulation of glucocerebroside within macrophages. Many mutations have been reported to be associated with this disorder. This study aimed to discover more mutations and provide data for the genetic pattern of the gene, which will help the development of quick and accurate genetic diagnostic tools for this disease. METHODS: Genomic DNA was obtained from peripheral blood leukocytes of the patient and Sanger sequencing is used to sequence GBA gene. Sequence alignments of mammalian ß-GBA (GCase) and three-dimensional protein structure prediction of the mutation were made. A construct of this mutant and its compound heterozygous counterpart were used to measure GCase in vitro. RESULTS: GCase is relatively conserved at p.T219A. This novel mutation differs from its wild-type in structure. Moreover, it also causes a reduction in GCase enzyme activity. CONCLUSION: This novel mutation (c.655A>G, p.T219A) is a pathogenic missense mutation, which contributes to GD.

Real-time polymerase chain reaction for diagnosing infectious mononucleosis in pediatric patients: A systematic review and meta-analysis.

In this meta-analysis, we evaluated the diagnostic role of Epstein-Barr virus deoxyribonucleic acid detection and quantitation in the serum of pediatric and young adult patients with infectious mononucleosis. The primary outcome of this meta-analysis was the sensitivity and specificity of Epstein-Barr virus (EBV) deoxyribonucleic acid (DNA) detection and quantitation using polymerase chain reaction (PCR). A systematic review and meta-analysis was performed by searching for articles that were published through September 24, 2014 in the following databases: Medline, Cochrane, EMBASE, and Google Scholar. The following keywords were used for the search: "Epstein-Barr virus," "infectious mononucleosis," "children/young adults/infant/pediatric," and "polymerase chain reaction or PCR." Three were included in this analysis. We found that for detection by PCR, the pooled sensitivity for detecting EBV DNA was 77% (95%CI, 66-86%) and the pooled specificity for was 98% (95%CI, 93-100%). Our findings indicate that this PCR-based assay has high specificity and good sensitivity for detecting of EBV DNA, indicating it may useful for identifying patients with infectious mononucleosis. This assay may also be helpful to identify young athletic patients or highly physically active pediatric patients who are at risk for a splenic rupture due to acute infectious mononucleosis.

Novel insights into a treatment for aplastic anemia based on the advanced proliferation of bone marrow­derived mesenchymal stem cells induced by fibroblast growth factor 1.

Aplastic anemia (AA) is rare disease that is predominantly observed in adolescents. Without effective management at an early stage, is associated with a high risk of mortality. Bone marrow mesenchymal stem cells (BMSCs) can differentiate into various types of cell, which are able to produce a number of hematopoietic growth factors considered to be important in AA alleviation. However, the mechanism underlying the role of fibroblast growth factor 1 (FGF1) in BMSC differentiation remains unknown. In the current study, the investigation focused on the regulatory role and potential signaling pathway of FGF1 in BMSC differentiation in patients exhibiting AA. BMSCs were infected with Ad­FGF1 and presented a potent proliferation capability, which was evaluated using Cell Counting kit­8 analysis. Reverse transcription­quantitative polymerase chain reaction revealed that long non­coding (lnc)RNA of testis development related gene 1 (TDRG1) was significantly upregulated, demonstrating high expression at the transcriptional level in the BMSCs that were infected with Ad­FGF1. The decreased proliferation capability of BMSCs that were treated with Ad­FGF1 and TDRG1­small interfering RNA validated the vital effect of TDRG1 on the FGF1 regulatory process of BMSC differentiation. Further experiments revealed that the increase of acetyl­histones, H3 and H4 was diminished in the TDRG1 promoter of BMSCs that were infected with Ad­FGF1, which indicated that the process of acetylation was promoted when the BMSCs were infected with Ad-FGF1. Thus, it was inferred that FGF1 induces the proliferation of BMSCs in patients with AA via promoting acetylation in lncRNA of the TDRG1 gene promoter.

Experimental bone marrow failure in mice ameliorated by OCH via tippling the balance of released cytokines from Th1 to Th2.

BACKGROUND: OCH was reported to stimulate natural killer T (NKT) cells to produce predominantly T helper type 2 (Th2) cytokines. The present study was attempted to evaluate potential protection of OCH on acquired bone marrow failure syndromes (BMFS) in mice model. METHODS: BMFS in mice model was established by exposure to sublethal irradiation followed by infusion with 5 × 10(6) B6 lymph nodes cells. Mice were injected intraperitoneally (I.P.) with either OCH or α-galactosylceramide (α-GC) at a dose of 100 µg kg(-1) twice a week for two weeks after post-irradiation. The control mice were I.P. with vehicle alone (10% dimethyl sulfoxide in phosphate-buffered saline). Meanwhile, anti-interleukin-4 (anti-IL-4) monoclonal antibody (mAb) (500 µg/animal) was given I.P. 2 hours prior to vehicle or OCH administration. Both interferon-γ (IFN-γ) and IL-4 levels in the serum were measured by enzyme-linked immunosorbent assay. Colony-forming unit-granulocyte-macrophage (CFU-GM) by bone marrow (BM) mononuclear cells was counted. The percentage of NKT cell in BM cells and intracellular cytokines were determined by flow cytometry. RESULTS: The treatment of OCH in vivo decreased the IFN-γ/IL-4 ratio in the serum, and increased the transformation of NKT cells into NKT2 cells. The treatment of OCH in vitro increased the colonies of CFU-GM. CONCLUSION: Our data suggests that OCH ameliorated immune-mediated BMFS in CByB6F1 mice via activation of NKT cells, and shifting the balance from Th1 to Th2.

Long term cultured HL-60 cells are intrinsically resistant to Ara-C through high CDA activity.

Cytarabine (araC) is a highly active antimetabolite against hematological malignancy while the agent shows limited activity for some patients despite maintenance or continued therapy with ara-C-containing regiments. In this study, we focused to elucidate the mechanism of intrinsic resistance to araC. The concentration of intracellular ara-CTP and incorporated ara-CTP were monitored in human leukemia cell line-HL-60 for different passages in parental with its variant HL-60R. The expression of mRNA for deoxycytidine kinase (dCK), cytidine deaminas (CDA), human equilibrative nucleoside transporter 1 (hENT1), and cytosolic 50-nucleotidase II (cN-II) were examined by Real-time PCR in HL-60 and HL-60R for different passages. And activities of two metabolizing enzymes for araC, dCK and CDA were further examined. The results showed that the concentration of intracellular ara-CTP was significantly reduced and the ara-U increased in HL-60 cells for 50 passages compared with the 5 passages, and associated with higher CDA activity. All the factors in HL-60R cells did not change by the incubation of ara-C. In conclusion, the long term cultured cells are intrinsically resistant to ara-C through high CDA activity, but not low DCK activity.

[Treatment of childhood aplastic anemia with antithymocyte globulin, management of side effects and long-term follow-up].

OBJECTIVE: To evaluate the efficacy of antithymocyte globulin (ATG) based immunosuppression therapy for childhood aplastic anemia, to reduce the adverse effects and to observe the long-term outcome. METHOD: Thirty-five children with aplastic anemia (AA) were enrolled in this study. Six of the cases had very severe AA (VSAA), 11 had severe AA (SAA)-I, 8 had SAA-II and 10 had moderate AA (MAA). All these patients were treated with ATG plus Cyclosporin A (CSA). The following measures were taken during the ATG therapy: infection of the patients had been controlled before ATG treatment. Comprehensive anti-allergic measures were implemented. Close attention was paid to the hemorrhage related with platelet reduction caused by ATG and severe infection of the patients. RESULT: Shortly after the ATG usage, all the patients had a significant decrease of absolute peripheral lymphoblast count by more than 60 percent. With a mean follow-up time of 28 months, the total effective rate was 77.14% (27/35), significant response rate was 57.14%(20/35). There was no significant difference among VSAA, SAA and MAA groups in the response rate. Adverse reactions included the following: (1) 48.6% (17/35) patients presented mild anaphylactoid reaction during the first day of ATG treatment; (2) 42.9%(15/35) cases presented serum sickness 5 - 11 days after the last dose of ATG with a mean duration of 3.6 days, all the patients were cured effectively with methylprednisolone; (3) 25.7% (9/35) patient's peripheral blood platelet count was reduced, might be caused by ATG, to below 10 × 10(9)/L, but no patient had severe hemorrhagic complication after platelet transfusion was performed; (4) 22.9%(8/35)of patients got infection within a month after ATG therapy, including 3 cases with clinical septicemia, all the 3 cases recovered after antibiotics treatment. There was no ATG treatment-related death in this series. CONCLUSION: ATG is a very effective therapy for children with SAA and MAA. Comprehensive measures are needed to prevent and handle the side effects to avoid treatment-related death. Long-term supportive therapy and proper follow up contribute to the favourable outcomes of the patients.

The benefit of ATG in immunosuppressive therapy of children with moderate aplastic anemia.

BACKGROUND: Previous studies specifically focused on the immunosuppressive therapy (IST) of children with moderate aplastic anemia (MAA) are rare. The aim of this study was to evaluate the advantage of using antithymocyte globulin (ATG) in the IST and its outcome of children with MAA. METHODS: Forty-two children diagnosed with moderate aplastic anemia from 1993 to 2006 were retrospectively reviewed. Eighteen patients treated with ATG, cyclosporin A (CSA), and androgen are defined as the ATG group, the other 24 patients treated with CSA and androgen are defined as the non-ATG group. Survival and hematological response of the two groups were studied. RESULTS: Response rate and transfusion-independent survival of the ATG group were both significantly higher than those of the non-ATG group (83.33 vs. 41.7%, p = .006; and 83.33 vs. 50%, p = .043, respectively). Compared with non-ATG group, fewer patients in ATG group progress to severe aplastic anemia (p = .03). CONCLUSION: Immunosuppressive therapy including ATG benefits children with moderate aplastic anemia.

[Relationship between the expression of the genes encoding the key enzymes for cytarabine metabolism and the pharmacokinetics of cytarabine in the treatment of childhood acute leukemia with high-dose cytarabine].

OBJECTIVE: It has been reported that high-dose cytarabine (HD-AraC) was very effective for childhood hematological malignancies, especially for improving the long-term survival of high-risk acute lymphoblastic leukemia (ALL), acute myeloid leukemia (AML), and T-cell lymphoid malignancies (T-ALL, T-cell non-Hodgkin's lymphoma). This study aimed to evaluate the pharmacokinetics of HD-AraC for childhood hematological malignancies, and the relationship between the expression of the genes coding the key enzymes for Ara-C metabolism with the outcome of the patients. METHODS: The drug levels of Ara-C in plasma and cerebrospinal fluid were detected with HPLC while HD-AraC was used, the expression of deoxycytidine kinase (dCK) and cytidine deaminase (CDA) mRNA in human leukemia cell lines and the bone marrow cells were investigated in 48 cases of childhood hematological malignancies with RT-PCR methods, and the relationship between the expression of these enzymes mRNA and the outcome of the patients was analyzed. RESULTS: (1) When HD-AraC was used, the plasma levels of Ara-C and Ara-U could be respectively about 50 times and 25 times higher than those obtained when the patients were treated with regular dose of Ara-C treatment, and the level of Ara-C in cerebrospinal fluid could reach about 10% of plasma level of Ara-C. (2) There were significantly different expressions of dCK mRNA in different childhood acute leukemia (AL) patients, which were markedly related to the chemotherapy results. The expression of dCK in ALL was much higher than that in AML and relapsed AL cases. There were no significant differences in expressions of dCK in T-ALL and B lineage ALL. (3) In vitro study found that the expressions of dCK and CDA mRNA did not change in leukemia cell lines incubated at different doses and times of Ara-C. CONCLUSIONS: HD-AraC was a very effective protocol for childhood hematological malignancies for it could significantly elevate the plasma and cerebrospinal fluid drug levels. The expression of dCK may be an important factor in predicting the long-term outcomes of children with hematological malignancies. Good long-term outcomes of the childhood T-ALL could be achieved as the B lineage ALL had been treated with HD-AraC regimen. As the expression levels of dCK were much lower, it may be necessary for the treatment of AML with HD-AraC for consecutive three days.