Search

Summary: Asparaginase is essential in childhood acute lymphoblastic leukaemia (ALL) treatment, however hypersensitivity reactions to pegylated asparaginase (PEG‐asparaginase) hampers anti‐neoplastic efficacy. Patients with PEG‐asparaginase hypersensitivity have been shown to possess zero asparaginase enzyme activity. Using this measurement to define the phenotype, we investigated genetic predisposition to PEG‐asparaginase hypersensitivity in a genome‐wide association study (GWAS). From July 2008 to March 2016, 1494 children were treated on the Nordic Society of Paediatric Haematology and Oncology ALL2008 protocol. Cases were defined by clinical hypersensitivity and no enzyme activity, controls had enzyme activity ≥ 100 iu/l and no hypersensitivity symptoms. PEG‐asparaginase hypersensitivity was reported in 13·8% (206/1494) of patients. Fifty‐nine cases and 772 controls fulfilled GWAS inclusion criteria. The CNOT3 variant rs73062673 on 19q13.42, was associated with PEG‐asparaginase allergy (P = 4·68 × 10−8). We further identified two signals on chromosome 6 in relation to HLA‐DQA1 (P = 9·37 × 10−6) and TAP2 (P = 1·59 × 10−5). This study associated variants in CNOT3 and in the human leucocyte antigen (HLA) region with PEG‐asparaginase hypersensitivity, suggesting that not only genetic variations in the HLA region, but also regulation of these genes are of importance in the biology of this toxicity. Furthermore, our study emphasizes the importance of using asparaginase enzyme activity measurements to identify PEG‐asparaginase hypersensitivity. [ABSTRACT FROM AUTHOR]

Symptomatic venous thromboembolism (VTE) occurs in five percent of children treated for acute lymphoblastic leukemia (ALL), but whether a genetic predisposition exists across different ALL treatment regimens has not been well studied. Methods: We undertook a genome-wide association study (GWAS) meta-analysis for VTE in consecutively treated children in the Nordic/Baltic acute lymphoblastic leukemia 2008 (ALL2008) cohort and the Australian Evaluation of Risk of ALL Treatment-Related Side-Effects (ERASE) cohort. A total of 92 cases and 1481 controls of European ancestry were included. Results: No SNPs reached genome-wide significance (p < 5 × 10−8) in either cohort. Among the top 34 single-nucleotide polymorphisms (SNPs) (p < 1 × 10−6), two loci had concordant effects in both cohorts: ALOX15B (rs1804772) (MAF: 1%; p = 3.95 × 10−7) that influences arachidonic acid metabolism and thus platelet aggregation, and KALRN (rs570684) (MAF: 1%; p = 4.34 × 10−7) that has been previously associated with risk of ischemic stroke, atherosclerosis, and early-onset coronary artery disease. Conclusion: This represents the largest GWAS meta-analysis conducted to date associating SNPs to VTE in children and adolescents treated on childhood ALL protocols. Validation of these findings is needed and may then lead to patient stratification for VTE preventive interventions. As VTE hemostasis involves multiple pathways, a more powerful GWAS is needed to detect combination of variants associated with VTE. [ABSTRACT FROM AUTHOR]