| 1. |
- Gerbek, Tina, et al.
(författare)
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Role of TPMT and ITPA variants in mercaptopurine disposition
- 2018
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Ingår i: Cancer Chemotherapy and Pharmacology. - : SPRINGER. - 0344-5704 .- 1432-0843. ; 81:3, s. 579-586
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Tidskriftsartikel (refereegranskat)abstract
- To explore the levels of thioguanine incorporated into DNA (DNA-TG), and erythrocyte levels of 6-thioguanine nucleotides (Ery-TGN) and methylated metabolites (Ery-MeMP) during 6-mercaptopurine (6MP)/Methotrexate (MTX) therapy of childhood acute lymphoblastic leukemia (ALL) and the relation to inosine triphosphatase (ITPA) and thiopurine methyltransferase (TPMT) gene variants. Blood samples were drawn during 6MP/MTX maintenance therapy from 132 children treated for ALL at Rigshospitalet, Copenhagen. The samples were analysed for thiopurine metabolites and compared to TPMT (rs1800460 and rs1142345) and ITPA (rs1127354) genotypes. Median DNA-TG (mDNA-TG) levels were higher in TPMT and ITPA low-activity patients as compared to wildtype patients (TPMT (LA) 549 vs. 364 fmol/A mu g DNA, p = 0.007, ITPA (LA) 465 vs. 387 fmol/A mu g DNA, p = 0.04). mDNA-TG levels were positively correlated to median Ery-TGN (mEry-TGN)(r (s) = 0.37, p = 0.001), but plateaued at higher mEry-TGN levels. DNA-TG indices (mDNA-TG/mEry-TGN) were 42% higher in TPMT (WT) patients as compared to TPMT (LA) patients but no difference in DNA-TG indices was observed between ITPA (WT) and ITPA (LA) patients (median 1.7 vs. 1.6 fmol/A mu g DNA/ nmol/mmol Hb, p = 0.81). DNA-TG indices increased with median Ery-MeMP (mEry-MeMP) levels (r (s) = 0.25, p = 0.001). TPMT and ITPA genotypes significantly influence the metabolism of 6MP. DNA-TG may prove to be a more relevant pharmacokinetic parameter for monitoring 6MP treatment intensity than cytosolic metabolites. Prospective trials are needed to evaluate the usefulness of DNA-TGN for individual dose adjustments in childhood ALL maintenance therapy.
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| 2. |
- Levinsen, Mette, et al.
(författare)
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Leukemic blasts are present at low levels in spinal fluid in one-third of childhood acute lymphoblastic leukemia cases
- 2016
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Ingår i: Pediatric Blood & Cancer. - : Wiley. - 1545-5009 .- 1545-5017. ; 63:11, s. 1935-1942
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Tidskriftsartikel (refereegranskat)abstract
- Background: Central nervous system (CNS) involvement is associated with relapse in childhood acute lymphoblastic leukemia (ALL) and is a diagnostic challenge. Procedure: In a Nordic/Baltic prospective study, we assessed centralized flow cytometry (FCM) of locally fixed cerebrospinal fluid (CSF) samples versus local conventional cytospin-based cytology (CC) for detecting leukemic cells and evaluating kinetics of elimination of leukemic cells in CSF. Results: Among 300 patients with newly diagnosed ALL, 87 (29%) had CSF involvement by FCM, while CC was positive in 30 (10%) of 299 patients with available CC data (P < 0.001). Patients with FCM+/CC+ had higher CSF leukemic blast counts compared to patients positive by FCM only (medians: 0.10 vs. 0.017 leukemic blasts/μl, P = 0.006). Patients positive by FCM had higher white blood cell counts in peripheral blood than patients negative by FCM (medians: 45 × 109/l vs. 10 × 109/l, P < 0.001), were younger (medians: 3 years vs. 4 years, P = 0.03), and more frequently had T-cell ALL (18/87 vs. 16/213, P = 0.001). At treatment day 15, five of 52 patients (10%) who had CSF positive by FCM at diagnosis remained so despite at least two doses of weekly intrathecal chemotherapy. Conclusions: Longer follow-up is needed to clarify whether FCM positivity has prognostic significance and is an indicator for intensified CNS-directed therapy.
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| 3. |
- Levinsen, Mette, et al.
(författare)
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Myelotoxicity after high-dose methotrexate in childhood acute leukemia is influenced by 6-mercaptopurine dosing but not by intermediate thiopurine methyltransferase activity
- 2015
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Ingår i: Cancer Chemotherapy and Pharmacology. - : Springer Science and Business Media LLC. - 0344-5704 .- 1432-0843. ; 75:1, s. 59-66
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Tidskriftsartikel (refereegranskat)abstract
- Through enhancement of 6-mercaptopurine (6MP) bioavailability and inhibition of purine de novo synthesis, high-dose methotrexate (HD-MTX) may increase incorporation into DNA of 6-thioguanine nucleotides, the cytotoxic metabolites of 6MP. Patients with intermediate activity of thiopurine methyltransferase (TPMTIA) have higher cytosol 6-thioguanine nucleotide levels. We investigated toxicity following HD-MTX during MTX/6MP maintenance therapy in relation to 6MP and TPMT. Using linear mixed models, we explored myelo- and hepatotoxicity in relation to 6MP dosage and TPMT phenotype following 1,749 HD-MTX courses to 411 children with acute lymphoblastic leukemia on maintenance therapy. The degree of myelosuppression following HD-MTX was similar for patients with TPMTIA and patients with high TPMT activity (TPMTHA), when HD-MTX started with same blood counts and 6MP doses. However, since TPMTIA had lower blood counts at initiation of HD-MTX compared with TPMTHA patients (median WBC 2.8 vs. 3.3 x 10(9)/L, P = 0.01; median ANC 1.4 vs. 1.7 x 10(9)/L, P = 0.02), TPMTIA continued to have lower WBC and ANC levels compared with TPMTHA during all 28 days after HD-MTX [relative difference 9 % (95 % CI 2-17), P = 0.02 and 21 % (95 % CI 6-39), P = 0.005]. Still, the fractional decrease in WBC and ANC levels after HD-MTX did not differ between TPMTIA and TPMTHA patients (P = 0.47; P = 0.38). The degree of leukopenia, neutropenia, thrombocytopenia and rise in aminotransferases were all significantly related to 6MP dose (P < 0.001 for all analyses). For both TPMTIA and TPMTHA patients, dose of 6MP prior to HD-MTX should be guided by pre-HD-MTX blood counts, but not by TPMT activity.
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| 4. |
- Oskarsson, Trausti, et al.
(författare)
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Treatment-related mortality in relapsed childhood acute lymphoblastic leukemia
- 2018
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Ingår i: Pediatric Blood & Cancer. - : Wiley. - 1545-5009 .- 1545-5017. ; 65:4
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Tidskriftsartikel (refereegranskat)abstract
- Background: Treatment of relapsed childhood acute lymphoblastic leukemia (ALL) is particularly challenging due to the high treatment intensity needed to induce and sustain a second remission. To improve results, it is important to understand how treatment-related toxicity impacts survival.Procedure: In this retrospective population-based study, we described the causes of death and estimated the risk for treatment-related mortality in patients with first relapse of childhood ALL in the Nordic Society of Paediatric Haematology and Oncology ALL-92 and ALL-2000 trials.Results: Among the 483 patients who received relapse treatment with curative intent, we identified 52 patients (10.8%) who died of treatment-related causes. Twelve of these died before achieving second remission and 40 died in second remission. Infections were the cause of death in 38 patients (73.1%), predominantly bacterial infections during the chemotherapy phases of the relapse treatment. Viral infections were more common following hematopoietic stem cell transplantation (HSCT) in second remission. Independent risk factors for treatment-related mortality were as follows: high-risk stratification at relapse (hazard ratio [HR] 2.2; 95% confidence interval [CI] 1.3-3.9; P < 0.01), unfavorable cytogenetic aberrations (HR 3.4; 95% CI 1.3-9.2; P = 0.01), and HSCT (HR 4.64; 95% CI 2.17-9.92; P < 0.001). In contrast to previous findings, we did not observe any statistically significant sex or age differences. Interestingly, none of the 17 patients with Down syndrome died of treatment-related causes.Conclusions: Fatal treatment complications contribute significantly to the poor overall survival after relapse. Implementation of novel therapies with reduced toxicity and aggressive supportive care management are important to improve survival in relapsed childhood ALL.
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| 5. |
- Tulstrup, Morten, et al.
(författare)
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Individualized 6-mercaptopurine increments in consolidation treatment of childhood acute lymphoblastic leukemia: A NOPHO randomized controlled trial.
- 2018
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Ingår i: European Journal of Haematology. - : Wiley. - 0902-4441 .- 1600-0609. ; 100:1, s. 53-60
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Tidskriftsartikel (refereegranskat)abstract
- This randomized controlled trial tested the hypothesis that children with non-high-risk acute lymphoblastic leukemia could benefit from individualized 6-mercaptopurine increments during consolidation therapy (NCT00816049). Primary and secondary end points were end of consolidation minimal residual disease (MRD) positivity and event-free survival.392 patients were randomized to experimental and 396 to standard therapy. Patients allocated to standard therapy received oral 6-mercaptopurine (25mg/m(2) /day) from days 30 to 85, while the experimental arm received stepwise increments of additional 25mg/m(2) /day beginning on days 50 and/or 71 unless dose-limiting myelosuppression had occurred.In the experimental arm, 166 patients (42%) received one dose increment, and 62 (16%) received two. Fifty-seven of 387 (15%) patients in the experimental arm were MRD positive at end of consolidation vs 77 of 389 (20%) in the control arm (P=.08). Five-year probability of event-free survival was 0.89 (95% CI: 0.85-0.93) in the experimental arm vs 0.93 (0.90-0.96) in the control arm (P=.13). The median accumulated length of 6-mercaptopurine treatment interruptions was 7 (IQR 2-12) in the experimental arm vs 4 (IQR 0-10) in the control arm (P=.002).This study found no benefit from individualized 6-mercaptopurine increments compared to standard therapy.
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| 6. |
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| 7. |
- Wolthers, Benjamin Ole, et al.
(författare)
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Insulin-dependent diabetes : a chronic complication to acute pancreatitis in childhood acute lymphoblastic leukemia
- 2019
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Ingår i: Pediatric Blood & Cancer. - : Wiley-Blackwell. - 1545-5009 .- 1545-5017. ; 66:1
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Tidskriftsartikel (refereegranskat)abstract
- Pancreatitis is a frequent toxicity to acute lymphoblastic leukemia (ALL) treatment, significantly associated with asparaginase use, and may be followed by severe complications such as acute hyperglycaemia, need for mechanical ventilation, pseudocysts, and death. Here, we provide novel data on seven patients diagnosed with diabetes after pancreatitis and still requiring insulin treatment after a median follow-up of 4.2 years (range: 1.7-9.2). We describe the clinical course of pancreatitis and illustrate the association between pancreatic pseudocysts, older age, and development of insulin-dependent diabetes. Together, this study documents the persisting burden of pancreatitis in childhood ALL and underlines the need for plasma glucose level monitoring.
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