Search

Hansamon Poparn,1,2 Yaowaree Kittikalayawong,1,2 Piti Techavichit,1,2 Supanun Lauhasurayotin,1,2 Kanhatai Chiengthong,1,2 Phumin Chaweephisal,2 Darintr Sosothikul1,2 1Division of Pediatric Hematology and Oncology, Department of Pediatrics, Faculty of Medicine, Chulalongkorn University, Bangkok, 10330, Thailand; 2Integrative and Innovative Hematology/Oncology Research Unit, Department of Pediatrics, Faculty of Medicine, Chulalongkorn University, Bangkok, 10330, ThailandCorrespondence: Darintr Sosothikul, Division of Pediatric Hematology and Oncology, Department of Pediatrics, Faculty of Medicine, Chulalongkorn University, Bangkok, 10330, Thailand, Tel/Fax +66 2-256-4949, Email dsosothikul@hotmail.com; Darintr.S@chula.ac.thAbstract: Since aspirin resistance is rarely assessed in pediatric patients and thrombosis might cause damage in vital organs, such as the myocardium or brain, we aimed to determine its incidence and the pivotal role of routine screening. The point-of-care test by platelet function analyzer (PFA-200) and bedside bleeding time (BT) was compared to standard whole blood impedance aggregometry (IA), the time-consuming and sophisticated assays. This single-center cross-sectional study was investigated in Thai children (≤ 15 years). All participants received at least five-day administrations of aspirin (3 to 5 mg/kg/day or equivalent to a single tablet of 81 mg) for any prior thrombotic risks. Platelet aggregation > 5 ohms on IA with 0.5 mM arachidonic acid, closure time < 180 seconds on collagen/epinephrine PFA-200, and modified Ivy BT ≤ 7 minutes, defined resistance. Of 37 patients, 2.7% had confirmed aspirin resistance to IA. Despite the 100% sensitivity, PFA-200 showed higher specificity than BT (83.3% vs 36.1%). However, both were not comparable (exact McNemar P < 0.05), with a slight/fair reliability (&kgreen;=0.215 vs &kgreen;=0.030 respectively). Aspirin resistance is uncommon in Thai children. Routine screening is discouraged but recommended only in cases with recurrent thrombosis despite good aspirin compliance or the presence of resistant risk factors. Although the gold standard IA could not be replaced, the rapid assay of PFA-200, not bedside BT, can potentially be considered a point-of-care alternative screening test to detect aspirin resistance in children.Keywords: aspirin, pediatrics, platelet function tests

Background: Intracranial germ cell tumors (IGCTs) are rare, highly curable neoplasms. KRAS is a gene in the KIT/RAS signaling pathway, and KRAS mutations have been reported in patients diagnosed with IGCTs., Objectives: To describe the clinicopathologic and molecular features of KRAS mutation and the treatment outcome of children diagnosed with IGCTs., Methods: Patients diagnosed with IGCTs at the Department of Pediatrics, King Chulalongkorn Memorial Hospital from 2007 to 2016 were retrospectively reviewed. DNA was extracted from formalin-fixed, paraffin-embedded tissue and used for molecular study. Mutations in codons 12, 13, and 61 of the KRAS gene were detected using the cobas® KRAS mutation test and pyrosequencing., Results: Eighteen patients were diagnosed with IGCTs (11 males and 7 females): nine with germinomas and nine with non-germinomatous GCTs (NGGCTs). The age range of the patients was 5-14 years (median 10.5 years). Elevated markers were revealed in approximately 25% of the patients. Four patients (two with germinomas and two with NGGCTs) had leptomeningeal involvement. All patients underwent tumor biopsy and received neoadjuvant chemotherapy. Radiotherapy was administered in 16 patients, and craniospinal radiation was administered only in patients with leptomeningeal metastasis. With a median follow-up of 26 months, overall survival was 88.9% in the patients with germinomas and 37% in the patients with NGGCTs. Mutation of the KRAS gene was detected using pyrosequencing in one patient. The mutation located at codon 61, with frequency 38.3% units, nucleotide substitution CAA > CTA, and amino acid substitution, was Q61L. The patient carrying the mutant gene was diagnosed with germinoma with cerebrospinal fluid metastasis and eventually died from treatment-related toxicity., Conclusion: Our study revealed the treatment outcomes of IGCTs in Thai children. The metastatic germinoma patient with KRAS codon 61 mutation had a poor outcome, supporting that Q61L has a clinical correlation with IGCTs.

Background: The BNT162b2 mRNA COVID-19 vaccine has been administered to children and adolescents with cancer and hematologic diseases since they are at high risk of manifesting severe symptoms if they have COVID-19 infection but the adequate immune response after vaccination in these immunocompromised patients are questionable., Objective: To evaluate the immune response of children and adolescents with cancer and hematologic diseases after receiving 2 doses of the BNT162b2 mRNA COVID-19 vaccine., Methods: This is a prospective cohort study of patients with cancer and hematologic disease, who aged 12- 18 years old and received 2 doses the BNT162b2 vaccines at 4 weeks apart were enrolled. Immunogenicity was determined by measuring serum anti-SARS-CoV-2 immunoglobulin antibodies directed against the receptor binding domain (RBD) of S1 domain of the spike protein (Anti S-RBD), surrogated viral neutralization test (sVNT) of SARS-CoV-2 and Delta strain. Blood samples were collected and analyzed at 4 and 12 weeks after vaccination. The seroprotective rate was defined as sVNT ≥ 68%., Results: From Oct 2021 to Jan 2022, 43 children were enrolled, 21 were on-therapy and 22 were off-therapy. 25 were hematologic malignancy, 15 solid tumor and 3 hematologic diseases with immunosuppressive drugs. The GMT (95%CI) of a anti S-RBD IgG level at 4 weeks after vaccination were 56.05 (13.2,238.2) and 3633 (2689,4908) BAU/mL in on-therapy and off-therapy group, respectively, p<0.001. The sVNT (95%CI) of delta strain were 26% (5.85-73.55%) and 97.05% (96.0-97.4%) as the seroprotective level which were 33.3% in on-therapy group and 100% in off-therapy group (p<0.001). 14 children in on-therapy group need an additional dose., Conclusion: After complete vaccination, the seroprotective rate and antibody level in pediatric and adolescent patients with cancer and hematologic disease who receive immunosuppressive agents are quite low, compared with patients who had complete treatment. Additional dose of primary series should be offered.

Background: Asparaginase is one of the essential chemotherapies used to treat acute lymphoblastic leukemia (ALL). Asparaginase antibody production may cause a subtherapeutic level and result in an inferior outcome. The aim of this study was to prove the efficacy of current native E.coli asparaginase-based protocol. Moreover, does subtherapeutic result appeared in small group of the trial?., Methods: A prospective study of asparaginase activity among patients who received native E.coli asparaginase 10,000 IU/m2 intramuscularly according to The Thai Pediatric Oncology Group (ThaiPOG) protocol was done. The plasma asparaginase activity was measured by the coupled enzymatic reaction. Pharmacokinetic data including peak activity (Cmax), time to maximum concentration (Tmax), area under the curve (AUC0-48h) being elucidated., Results: Eight patients (five males and three females), median age 9.5 years, were enrolled. The median asparaginase activity of seven cases who were eligible for calculation reached Tmax within 24 hours (range 6-48 hours) with mean±SD of Cmax 3.60±0.34 (range 3.02-4.11) IU/ml. Mean±SD of AUC0-48h is 143.23±36.94 IU.h/mL (range 71.07 - 180.12 IU.h/mL). The post-48-hour activity showed a mean±SD of 3.19±0.24 IU/ml (range 2.77-3.51 IU/ml) which implied an adequacy of activity over 48 hours and proper for the 12-day period. One relapsed ALL patient showed an extremely low AUC of asparaginase activity which coincided with urticaria after asparaginase injection. Subsequently, the asparaginase antibody was demonstrated in this patient., Conclusion: Native E. coli asparaginase-based protocol provides a compelling pharmacokinetic effect. Asparaginase activity and/or antibody testing is recommended for all cases especially in a relapsed patient, history of high accumulative dose of asparaginase or suspected allergic reaction. Patients with low asparaginase activity or allergy may benefit from switching to an alternative form of asparaginase to maintain treatment efficacy.

Thalassemia is the most common hematological transfusion-dependent disease in Thailand. Even though prenatal diagnosis (PND) can detect the condition, many new cases are diagnosed in pediatric practice. This study assessed the clinical outcome of patients with thalassemia who did PND. One hundred and six participants (53 female, 50%), with a median age of 8.5 years (Interquartile range [IQR] 8.00), were enrolled in the study. Twenty-one participants (19.8%) were prenatally diagnosed with thalassemia, with a median age of 8 years (IQR 9.00), 16 were diagnosed with transfusion-dependence thalassemia (TDT), and 5 participants were diagnosed with non-TDT. Another 80.2% did not prenatally diagnose, with a median age of 9 years (IQR 8.00). The PND group found early diagnosis compared with a non-PND group, at a median age of 6 months versus 15 months. There was a significant early diagnosis ( P  < .001). Furthermore, the participants' height for age z -score was significantly superior in the PND group ( P  = .018). Even though the result of PND was abnormal, the parents still willing to continue with the pregnancy. The reason was they wanted to have a child. However, their child may require lifelong transfusion therapy., Competing Interests: Declaration of Conflicting Interests: The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article., (© The Author(s) 2021.)

Transfusion-dependent thalassemia (TDT) patients require regular blood transfusions. The unavoidable consequence is iron overload. Iron chelation therapy is the mainstay of treatment, of which the favorable outcome depends mainly on adherence level. The aim of this study was to assess adherence to iron chelation therapy of TDT patients. A cross-sectional cohort of TDT patients were evaluated on their adherence to chelation therapy using the Thai version of Morisky Medication Adherence Scales (MMAS-8). A total of 70 patients (38 males, 32 females), with a median age of 10 years, were enrolled in the study. Sixteen patients (22.9%) and 54 patients (77.1%) were classified as high and medium-low adherence level groups. The raised serum ferritin value for 6 months previous to enrollment in the high adherence level group is lower than the medium-low adherence level group (276.4 vs. 413.0 ng/mL, p = 0.034, respectively). Factors impacted high adherence to iron chelation including younger age ( p  = 0.015) and deferasirox (DFX) administration ( p  = 0.025). The body weight and height in both groups were not statistically different. The most common obstacle to adherence was forgetfulness. The Thai version of MMAS-8 is a practical tool for evaluating adherence to chelation therapy in TDT patients. High adherence level of patients correlates with more controlled serum ferritin level. The younger age and once-daily dose chelation therapy are associated with better adherence.

Objective: The study aimed to describe the pattern of causative microorganisms, drug susceptibility, risk factors of antibiotic-resistant bacterial infection, and clinical impact of these organisms on pediatric oncology patients with febrile neutropenia., Methods: A retrospective descriptive study of oncologic patients aged less than 15 years who were diagnosed with febrile neutropenia in King Chulalongkorn Memorial Hospital was conducted between January 2013 to December 2017. Characteristics and clinical outcomes of febrile neutropenia episodes, causative pathogens, and their antibiotic susceptibilities were recorded., Result: This study included 267 patients with 563 febrile neutropenia episodes. The median (range) age was 5.1 years (1 month-15 years). The most common underlying disease was acute lymphoblastic leukemia (42.7%). Of 563 febrile episodes, there were 192 (34.1%) with microbiologically documented infection. Among these 192 episodes of microbiologically documented infection, there were 214 causative pathogens: 154 bacteria (72%), 32 viruses (15%), 27 fungus (12.6%), and 1 Mycobacterium tuberculosis (0.4%). Gram-negative bacteria (48.6%) accounted for most of the causative pathogens. Twenty-three percent of them were multidrug resistant, and 18% were carbapenem resistant. Among Gram-positive bacterial infection which accounted for 23.4% of all specimens, the proportion of MRSA was 20%. The 2-week mortality rate was 3.7%. Drug-resistant Gram-negative bacterial infection caused significant adverse events and mortality compared to nonresistant bacterial infection ( p < 0.05)., Conclusion: There is high rate of drug-resistant organism infection in pediatric oncology patients in a tertiary-care center in Thailand. Infection with drug-resistant Gram-negative bacterial infection was associated with significant morbidity and mortality. Continuous surveillance for the pattern of drug-resistant infections is crucial., Competing Interests: The authors declare that they have no conflicts of interest., (Copyright © 2021 Thanyathorn Jungrungrueng et al.)

Objectives: Febrile neutropenia (FN) is severe and potentially life-threatening in oncologic patients. The objective of this study is to define the factors associated with severe adverse outcomes of pediatric FN., Methods: A retrospective and prospective descriptive study performed in pediatric patients diagnosed with FN at King Chulalongkorn Memorial Hospital from January 2013 to December 2017. Severe adverse events defined as the presence in one of these following oxygen therapies, mechanical ventilator, shock, admission to ICU, renal dysfunction, and liver dysfunction., Results: The study included 267 patients with 563 febrile neutropenia episodes. The median (range) age was 5.1 years (1 month-15 year). Among 563 febrile neutropenia episodes, 115 episodes (20%) developed severe adverse events. The FN patients were classified into low and high-risk groups, 91% of patients with severe adverse events and all 21 patients who died were in high risk group. The overall mortality rate was 3.1%. Factors associated with severe adverse events were fungal infection (aOR 6.51, 95%CI 2.29-18.56), central venous catheter insertion (aOR 4.28, 95% CI 2.51-7.29), CPG defined high risk (aOR 3.35, 95%CI 1.56-7.17), viral infection (aOR 2.72, 95%CI 1.05-7.06), lower respiratory tract infection (aOR 2.52, 95%CI 1.09-5.82) and treatment not according to CPG (aOR 2.47, 95% CI 1.51-4.03)., Conclusions: Fungal and viral infection, central venous catheter insertion, lower respiratory tract infection, CPG defined high risk and treatment not according to CPG were associated factors of increased risk for severe adverse events. Our current institutional CPG for FN in children was applicable and improved clinical outcomes for this group of patients. , .