The Effect of NUDT15, TPMT, APEX1, and ITPA Genetic Variations on Mercaptopurine Treatment of Pediatric Acute Lymphoblastic Leukemia.

Mercaptopurine (MP) is a commonly used maintenance regimen for childhood acute lymphoblastic leukemia (ALL). However, 6-MP has a narrow therapeutic index, which causes dose-limiting toxicities in hematopoietic tissues. Recent studies reported several candidate pharmacogenetic markers such as TPMT, NUDT15, ITPA, and APEX1, which predict the possibility of 6-MP related toxicities. The aim of this study is to evaluate the effect of major variants of these genes on 6-MP intolerances and toxicities in pediatric acute lymphoblastic leukemia (ALL) patients. A total of 83 pediatric ALL patients were included (56 males and 27 females). The NUDT15 c.415C>T (rs116855232), NUDT15 c.55_56insGAGTCG (rs746071566), ITPA c.94C>A (rs1127354), ITPA c.IVS2+21A>C (rs7270101), APEX c.190A>G (rs2307486), and TPMT variants were analyzed by sanger sequencing. Correlations between indexes of 6-MP-related toxicities or 6-MP intolerance (absolute neutrophil count [ANC] at several time point, days of ANC < 1 × 103/mm3, days of ANC < 0.5 × 103/mm3, frequency of febrile neutropenia, maximum AST and ALT, 6-MP dose and 6-MP dose intensity during maintenance therapy) and genetic variations were analyzed. The NUDT15 c.415C>T allele carrier showed significantly low 6-MP doses at the final maintenance therapy period than the wild type carrier (p = 0.007). The 6-MP dose intensities at the sixth and final maintenance period were also significantly low in NUDT15 c.415C>T carriers (p = 0.003 and 0.008, respectively). However, indexes for neutropenia, days of febrile neutropenia, maximum AST, and ALT levels were not associated with the presence of c.415C>T as well as other analyzed variants. When analyzing the effect of the coexistence of NUDT15 c.415C>T and ITPA c.94C>A, no significant differences were found between the NUDT15 c.415C>T carrier and carrier with both variations. The NUDT15 c.415C>T was the most useful marker to predict 6-MP intolerance among analyzed variants in our study population. Although we could not find association of those variants with 6-MP induced toxicities and the synergistic effects of those variants, a well-planed larger scale study would be helpful in clarifying new candidates and their clinical effects.

A retrospective analysis of etiology and outcomes of hemophagocytic lymphohistiocytosis in children and adults.

BACKGRUOUND: Hemophagocytic lymphohistiocytosis (HLH) is a rare but severe, life-threatening inflammatory condition if untreated. We aimed to investigate the etiologies, outcomes, and risk factors for death in children and adults with HLH. METHODS: The medical records of patients who met the HLH criteria of two regional university hospitals in Korea between January 2001 and December 2019 were retrospectively investigated. RESULTS: Sixty patients with HLH (35 children and 25 adults) were included. The median age at diagnosis was 7.0 years (range, 0.1-83 years), and the median follow-up duration was 8.5 months (range, 0-204 months). Four patients had primary HLH, 48 patients had secondary HLH (20 infection-associated, 18 neoplasm-associated, and 10 autoimmune-associated HLH), and eight patients had HLH of unknown cause. Infection was the most common cause in children (14/35, 40.0%), whereas neoplasia was the most common cause in adults (13/25, 52.0%). Twenty-eight patients were treated with HLH-2004/94 immunochemotherapy. The 5-year overall survival (OS) rate for all HLH patients was 59.9%. The 5-year OS rates for patients with primary, infection-associated, neoplasm-associated, autoimmune-associated, and unknown cause HLH were 25.0%, 85.0%, 26.7%, 87.5%, and 62.5%, respectively. Using multivariate analysis, neoplasm-induced HLH (p=0.001) and a platelet count <50×109/L (p=0.008) were identified as independent risk factors for poor prognosis in patients with HLH. CONCLUSION: Infection was the most common cause of HLH in children, while it was neoplasia in adults. The 5-year OS rate for all HLH patients was 59.9%. HLH caused by an underlying neoplasm or a low platelet count at the time of diagnosis were risk factors for poor prognosis.

Survival and Prognosis of Patients with Pilocytic Astrocytoma: A Single-Center Study.

BACKGROUND: Pilocytic astrocytoma (PA) is a brain tumor that is relatively more common in children and young adults. METHODS: We retrospectively reviewed the medical records of patients with PA treated at a single center between 1988 and 2018. RESULTS: We included 31 subjects with PA. The median age at diagnosis was 13.4 years, and the median follow-up duration was 9.9 years. The total PA group had a 10-year disease-specific survival (DSS) rate of 92.6% [95% confidence interval (CI), 82.6-100] and 10-year progression-free survival (PFS) rate of 52.8% (95% CI, 32.0-73.6). In patients aged <20 years, tumors were more likely to be located in sites in which gross total tumor resection (GTR) was impossible. No statistically significant difference in 10-year DSS was found between the GTR (100%) and non-GTR (89.7%; 95% CI, 76.2-100; p=0.374) groups. However, a statistically significant difference in 10-year PFS was found between the GTR (100%) and non-GTR groups (30.7%; 95% CI, 8.6-52.8; p=0.012). In the non-GTR group, no statistically significant difference in 10-year DSS was found between the patients who received immediate additional chemotherapy and/or radiotherapy (Add-Tx group, 92.9%; 95% CI, 79.4-100) and the non-Add-Tx group (83.3%; 95% CI, 53.5-100; p=0.577). No statistically significant difference in 10-year PFS was found between the Add-Tx group (28.9%; 95% CI, 1.7-56.1) and non-Add-Tx group (33.3%; 95% CI, 0-70.9; p=0.706). CONCLUSION: The PFS of the patients with PA in our study depended only on the degree of surgical excision associated with tumor location. This study is limited by its small number of patients and retrospective nature. A multicenter and prospective study is necessary to confirm these findings.

A cross-sectional retrospective study to analyze the underlying causes and clinical characteristics of children with reactive thrombocytosis at a Korean tertiary medical center.

BACKGROUND: Reactive thrombocytosis (RT) is a common condition among children, although no studies have examined the etiology or clinical characteristics of RT among Korean children. METHODS: This retrospective study evaluated children with RT at a single Korean tertiary center during a 10-year period. RESULTS: RT accounted for 13.5% of children who were admitted to the pediatric ward (4,113/30,355): mild RT, 82.7%; moderate RT, 14.1%; severe RT, 1.1%; and extreme RT, 2.1%. There was a negative correlation between platelet count and Hb level (P=0.008). There were positive correlations between platelet count and WBC (P=0.001), erythrocyte sedimentation rate (ESR) (P=0.007), and admission duration (P=0.006). The most common cause of RT was infection and the second most common was Kawasaki disease (KD). The highest proportion of lower respiratory tract infection was observed in extreme RT (P<0.001). The proportion of KD was highest in extreme RT (P<0.001) and in children aged 1-7.9 years (P<0.001). The proportion of refractory KD was highest in extreme RT (P=0.005). In cases of KD, there was a positive correlation between platelet count and fever duration (P=0.006). Non-KD autoimmune inflammation was only observed in mild/moderate RT, and its proportion was highest in children aged 8-18 years (P<0.001). CONCLUSION: In children, more severe RT was associated with lower Hb, increased WBC, ESR, and prolonged admission. With respiratory infection or KD, extreme RT was associated with more severe disease course.

Comparison of survival outcome between donor types or stem cell sources for childhood acute myeloid leukemia after allogenic hematopoietic stem cell transplantation: A multicenter retrospective study of Study Alliance of Yeungnam Pediatric Hematology-oncology.

We compared transplant outcomes between donor types and stem cell sources for childhood acute myeloid leukemia (AML). The medical records of children with AML in the Yeungnam region of Korea from January 2000 to June 2017 were reviewed. In all, 76 children with AML (male-to-female ratio = 46:30) received allogenic hematopoietic stem cell transplantation (allo-HSCT). In total, 29 patients received HSCT from either a matched-related donor or a mismatched-related donor, 32 patients received an unrelated donor, and 15 patients received umbilical cord blood. In term of stem cell sources, bone marrow was used in 15 patients and peripheral blood in 46 patients. For all HSCT cases, the 5-year overall survival (OS) was 73.1% (95% CI: 62.7-83.5) and the 5-year event-free survival (EFS) was 66.1% (95% CI: 54.5-77.7). There was no statistical difference in 5-year OS according to the donor types or stem cell sources (P = .869 and P = .911). There was no statistical difference in 5-year EFS between donor types or stem cell sources (P = .526 and P = .478). For all HSCT cases, the 5-year relapse rate was 16.1% (95% CI: 7.3-24.9) and the 5-year non-relapse mortality (NRM) was 13.3% (95% CI: 5.1-21.5). There was no statistical difference in the 5-year relapse rate according to the donor types or stem cell sources (P = .971 and P = .965). There was no statistical difference in the 5-year NRM between donor types or stem cell sources (P = .461 and P = .470).

A case of inherited type 1 and type 2A von Willebrand disease confirmed by diagnostic exome sequencing.

A 10-year-old male and his family members visited a pediatric hematology clinic due to coagulopathy. Laboratory tests indicated von Willebrand disease (vWD) in all the family members. We conducted diagnostic exome sequencing for confirmation. The patient was confirmed to be a compound heterozygote for vWD: c.2574C > G (p.Cys858Trp) from his father (known variant of vWD type 1) and c.3390C > T (p.Pro1127_Gly1180delinsArg) from his mother (variant known to result in exon 26 skipping in vWD type 2A). He was managed with factor VIII and von Willebrand factor complex concentrate during palatoplasty due to bleeding despite pre-operative desmopressin injection. The operation was completed successfully.

Diagnostic accuracy of urinary biomarkers in infants younger than 3 months with urinary tract infection.

PURPOSE: The aim of this study was to evaluate the diagnostic accuracy of urinary biomarkers, such as neutrophil gelatinase-associated lipocalin (uNGAL) and ß-2 microglobulin (uB2MG), in early detection of urinary tract infection (UTI) in infants aged <3 months with fever. METHODS: A total of 422 infants aged <3 months (male:female=267:155; mean age, 56.4 days), who were admitted for fever, were retrospectively included in this study. We compared uNGAL and uB2MG between the UTI and non-UTI groups at the time of admission. The sensitivity, specificity, accuracy, and area under the curve (AUC) of uNGAL and uB2MG for use in diagnosing UTI were assessed. RESULTS: Among 422 patients, 102 (24.2%) were diagnosed with UTI. Levels of uNGAL were higher in the UTI group than in the non-UTI group (366.6 ng/mL vs. 26.9 ng/mL, P<0.001). Levels of uB2MG were not different between the 2 groups. Multivariate analysis revealed that uNGAL was an independent predictive factor for UTI (P=0.033). The sensitivity, specificity, and accuracy were 90.2%, 92.5%, and 91.9% for uNGAL, and 48.0%, 43.8%, and 44.8% for uB2MG, respectively. AUC of uNGAL was 0.942 and that of uB2MG was 0.407. CONCLUSION: Accuracy of uNGAL in the diagnosis of UTI is high in febrile infants aged <3 months. uNGAL can help in the early diagnosis and treatment of UTI in infants.

Short stature and growth hormone deficiency in a girl with encephalocraniocutaneous lipomatosis and Jaffe-Campanacci syndrome: a case report.

A 9-year-old Tajikistani girl presented to Keimyung University Dongsan Medical Center for evaluation of a skin lesion on her left eyelid, focal alopecia, unilateral ventricular dilatation, and aortic coarctation. She was diagnosed with encephalocraniocutaneous lipomatosis (ECCL) according to Moog's diagnostic criteria. Café-au-lait spots were found on the left side of her trunk. Multiple nonossifying fibromas were found on her left proximal humerus, left distal femur, both proximal tibias, and left proximal fibula, suggesting Jaffe-Campanacci syndrome (JCS), following imaging of the extremities. Many JCS cases with multiple Café-au-lait macules, multiple nonossifying fibromas may actually have Neurofibromatosis type-1 (NF1). Thus, comprehensive molecular analysis to exclude NF1 mutation was performed using her blood sample. The NF1 mutation was not found. Her height was under the 3rd percentile and her bone age was delayed as compared with her chronological age. Baseline growth hormone (GH) level was below the normal range. Using the insulin stimulation and levo-dihydroxyphenylalanine tests, GH deficiency was confirmed. We present a case of GH deficiency with typical features of ECCL and JCS.