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Introduction: Nuwiq® (Human‐cl rhFVIII) is a fourth generation recombinant FVIII, produced in a human cell line, without chemical modification or protein fusion. No inhibitors developed in studies with Nuwiq® in 201 previously treated patients with haemophilia A (HA). The immunogenicity, efficacy and safety of Nuwiq® in previously untreated patients (PUPs) with severe HA are being assessed in the ongoing NuProtect study. Methods: The study, conducted across 38 centres worldwide, is evaluating 110 true PUPs of all ages and ethnicities enrolled for study up to 100 exposure days (EDs) or 5 years maximum. The primary objective is to assess the immunogenicity of Nuwiq® (inhibitor activity ≥0.6 BU) using the Nijmegen‐modified Bethesda assay at a central laboratory. Results: Data for 66 PUPs with ≥20 EDs from a preplanned interim analysis were analysed. High‐titre (HT) inhibitors developed in 8 of 66 patients after a median of 11.5 EDs (range 6‐24). Five patients developed low‐titre inhibitors (4 transient). The cumulative incidence (95% confidence interval) was 12.8% (4.5%, 21.2%) for HT inhibitors and 20.8% (10.7%, 31.0%) for all inhibitors. During inhibitor‐free periods, median annualized bleeding rates during prophylaxis were 0 for spontaneous bleeds and 2.40 for all bleeds. Efficacy was rated as “excellent” or “good” in treating 91.8% of bleeds. Efficacy of surgical prophylaxis was “excellent” or “good” for 8 (89%) procedures and “moderate” for 1 (11%). No tolerability concerns were evident. Conclusion: These interim data show a cumulative incidence of 12.8% for HT inhibitors and convincing efficacy and tolerability in PUPs treated with Nuwiq®. [ABSTRACT FROM AUTHOR]

The risk of childhood acute lymphoblastic leukaemia (ALL) was investigated in relation to breastfeeding patterns in the Northern California Childhood Leukaemia Study. Data collected by self-administered and in-person questionnaires from biological mothers of leukaemia cases (age 0-14 years) in the period 1995-2002 were matched to birth certificate controls on date of birth, sex, Hispanic ethnic status, and maternal race. Ever compared to never breastfeeding was not associated with risk of ALL at ages 1-14 years (odds ratio=0.99; 95% CI=0.64-1.55) and ages 2-5 years (OR=1.49; 95% CI=0.83-2.65). Various measures of breastfeeding duration compared to absence of breastfeeding also had no significant effect on risk. Complimentary feeding characteristics such as type of milk/formula used and age started eating solid foods among breastfed children were not associated with ALL risk. This study provides no evidence that breastfeeding affects the occurrence of childhood ALL. [ABSTRACT FROM AUTHOR]

Background: The prevention of bleeding with adequately sustained levels of clotting factor, after a single therapeutic intervention and without the need for further medical intervention, represents an important goal in the treatment of hemophilia.Methods: We infused a single-stranded adeno-associated viral (AAV) vector consisting of a bioengineered capsid, liver-specific promoter and factor IX Padua (factor IX-R338L) transgene at a dose of 5×1011 vector genomes per kilogram of body weight in 10 men with hemophilia B who had factor IX coagulant activity of 2% or less of the normal value. Laboratory values, bleeding frequency, and consumption of factor IX concentrate were prospectively evaluated after vector infusion and were compared with baseline values.Results: No serious adverse events occurred during or after vector infusion. Vector-derived factor IX coagulant activity was sustained in all the participants, with a mean (±SD) steady-state factor IX coagulant activity of 33.7±18.5% (range, 14 to 81). On cumulative follow-up of 492 weeks among all the participants (range of follow-up in individual participants, 28 to 78 weeks), the annualized bleeding rate was significantly reduced (mean rate, 11.1 events per year [range, 0 to 48] before vector administration vs. 0.4 events per year [range, 0 to 4] after administration; P=0.02), as was factor use (mean dose, 2908 IU per kilogram [range, 0 to 8090] before vector administration vs. 49.3 IU per kilogram [range, 0 to 376] after administration; P=0.004). A total of 8 of 10 participants did not use factor, and 9 of 10 did not have bleeds after vector administration. An asymptomatic increase in liver-enzyme levels developed in 2 participants and resolved with short-term prednisone treatment. One participant, who had substantial, advanced arthropathy at baseline, administered factor for bleeding but overall used 91% less factor than before vector infusion.Conclusions: We found sustained therapeutic expression of factor IX coagulant activity after gene transfer in 10 participants with hemophilia who received the same vector dose. Transgene-derived factor IX coagulant activity enabled the termination of baseline prophylaxis and the near elimination of bleeding and factor use. (Funded by Spark Therapeutics and Pfizer; ClinicalTrials.gov number, NCT02484092 .). [ABSTRACT FROM AUTHOR]

Introduction: The phase 2/3 PROTECT VIII study demonstrated long-term efficacy and safety of damoctocog alfa pegol (BAY 94-9027; Jivi®), a B-domain-deleted recombinant factor VIII (FVIII), site-specifically PEGylated to improve its pharmacokinetic profile. We report a post hoc assessment of bleeding and safety outcomes in the subgroup of patients, aged 12-<18 years at enrolment., Method: PROTECT VIII was a multicentre, open-label study of previously treated males aged 12-65 years with severe haemophilia A (FVIII <1%). Twelve patients were included in this analysis. All received damoctocog alfa pegol prophylaxis for the total time in study (median [range] time in study 4.0 [1.3-6.2] years)., Results: Overall median (Q1; Q3) total and joint annualised bleeding rates were 1.8 (0.4; 5.1) and 0.7 (0.2; 1.8), respectively, for the entire study. During the last 6 months of treatment, eight (66.7%) and ten (83.3%) out of 12 patients experienced zero total and joint bleeds, respectively. No patient developed FVIII inhibitors. No deaths or thrombotic events were reported., Conclusion: Efficacy and safety of damoctocog alfa pegol were confirmed in adolescent patients with haemophilia A, with data for up to 6 years supporting its use as a long-term treatment option in this group as they transition into adulthood., Introduction: The phase 2/3 PROTECT VIII study demonstrated long-term efficacy and safety of damoctocog alfa pegol (BAY 94-9027; Jivi®), a B-domain-deleted recombinant factor VIII (FVIII), site-specifically PEGylated to improve its pharmacokinetic profile. We report a post hoc assessment of bleeding and safety outcomes in the subgroup of patients, aged 12-<18 years at enrolment., Method: PROTECT VIII was a multicentre, open-label study of previously treated males aged 12-65 years with severe haemophilia A (FVIII <1%). Twelve patients were included in this analysis. All received damoctocog alfa pegol prophylaxis for the total time in study (median [range] time in study 4.0 [1.3-6.2] years)., Results: Overall median (Q1; Q3) total and joint annualised bleeding rates were 1.8 (0.4; 5.1) and 0.7 (0.2; 1.8), respectively, for the entire study. During the last 6 months of treatment, eight (66.7%) and ten (83.3%) out of 12 patients experienced zero total and joint bleeds, respectively. No patient developed FVIII inhibitors. No deaths or thrombotic events were reported., Conclusion: Efficacy and safety of damoctocog alfa pegol were confirmed in adolescent patients with haemophilia A, with data for up to 6 years supporting its use as a long-term treatment option in this group as they transition into adulthood., (© 2024 The Author(s). Published by S. Karger AG, Basel.)

Damoctocog alfa pegol (BAY 94-9027, Jivi ® ), is a site-specifically PEGylated, extended half-life recombinant factor VIII (FVIII) that is approved in several European and non-European countries for on-demand treatment and prophylaxis of bleeding in previously treated patients aged ≥ 12 years with hemophilia A. Reliable measurements can be obtained using most one-stage and chromogenic FVIII assays over a wide concentration range. The efficacy, safety and pharmacokinetics (PK) of damoctocog alfa pegol have been studied extensively in the PROTECT VIII clinical trials, and its long-term safety and effectiveness profile is continuing to build through observational and interventional real-world studies. The PK of damoctocog alfa pegol was shown to be improved as compared with that of sucrose-formulated rFVIII (rFVIII-FS, Kogenate ® ), and was also demonstrated to be non-inferior to and, for some variables, more favorable than rFVIII-Fc fusion protein, efmoroctocog alfa (Elocta ® ; NCT03364998), rurioctocog alfa pegol (BAX 855, Adynovate ® /Adynovi ® ; NCT04015492), and antihemophilic factor (recombinant) plasma/albumin-free method (rAHF-PFM, Advate ® ; NCT02483208). Damoctocog alfa pegol was generally well tolerated and none of the patients in any of the clinical trials, including the PROTECT VIII clinical program, HEM-POWR, or ongoing single-center studies, developed FVIII inhibitors. Efficacy for perioperative hemostasis has been demonstrated. Low bleeding rates were achieved across the studies, with twice weekly, every 5-day and every 7-day prophylaxis offering patients ≥ 12 years and their clinicians the chance to tailor treatment to individual needs and lifestyles, while maintaining long-term protection from bleeds and their consequences., (© 2024. The Author(s).)

Introduction: Simoctocog alfa (Nuwiq®) is a 4th generation recombinant FVIII with proven efficacy for the prevention and treatment of bleeding episodes (BEs) in previously treated patients with severe haemophilia A. The NuProtect study assessed the immunogenicity, efficacy and safety of simoctocog alfa in 108 previously untreated patients (PUPs). The incidence of high-titre inhibitors was 16.2% and no patients with non-null F8 mutations developed inhibitors., Aim: To report the efficacy and safety results from the NuProtect study., Methods: PUPs received simoctocog alfa for prophylaxis, treatment of BEs, or as surgical prophylaxis. The efficacy of prophylaxis (during inhibitor-free periods) was assessed using annualised bleeding rates (ABRs). The efficacy in treating BEs and in surgical prophylaxis was assessed using a 4-point scale. Adverse events were recorded throughout the study., Results: Of 108 PUPs treated with simoctocog alfa, 103 received at least one prophylactic dose and 50 received continuous prophylaxis for at least 24 weeks. In patients on continuous prophylaxis, the median ABR was 0 (mean 0.5) for spontaneous BEs and 2.5 (mean 3.6) for all BEs. In 85 patients who had BEs, efficacy of BE treatment was excellent or good for 92.9% (747/804) of rated BEs; 92.3% of BEs were treated with 1 or 2 infusions. The efficacy of surgical prophylaxis was excellent or good for 94.7% (18/19) of rated procedures. There were no safety concerns and no thromboembolic events., Conclusion: Simoctocog alfa was efficacious and well tolerated as prophylaxis, surgical prophylaxis and for the treatment of BEs in PUPs with severe haemophilia A., (© 2023 The Authors. European Journal of Haematology published by John Wiley & Sons Ltd.)

Background: The NuProtect study reported data on the immunogenicity, efficacy and tolerability of simoctocog alfa (Nuwiq ® ) in 108 previously untreated patients with severe haemophilia A planned to be treated for ≥100 exposure days or up to 5 years. The NuProtect-Extension study collected long-term prophylaxis data in children with severe haemophilia A., Methods: Patients who completed the NuProtect study according to the protocol were eligible for the NuProtect-Extension study, a prospective, multinational, non-controlled, Phase 3b study., Results: Of 48 patients who entered the extension study, 47 (median age 2.8 years) received prophylaxis with simoctocog alfa for a median of 24 months, with 82%-88% on a twice-weekly or less regimen. No patient developed FVIII inhibitors during the extension study. The median (IQR) annualized bleeding rate (ABR) during prophylaxis was 0 (0-0.5) for spontaneous bleeding episodes (BEs) and 1.00 (0-1.95) for all BEs. ABRs estimated using a negative binomial model were .28 (95% CI: .15, .53) for spontaneous and 1.62 (95% CI: 1.09, 2.42) for all BEs. During the median follow-up of 24 months, 34 (72%) patients had zero spontaneous BEs and 46 (98%) had zero spontaneous joint BEs. Efficacy in treating BEs was excellent or good for 78.2% of rated BEs, and efficacy of surgical prophylaxis was excellent for two rated surgeries. No treatment-related adverse events were reported., Conclusion: No FVIII inhibitors developed during long-term prophylaxis in the NuProtect-Extension study. Prophylaxis with simoctocog alfa was efficacious and well-tolerated, and is therefore an attractive long-term option for children with severe haemophilia A., (© 2023 The Authors. Haemophilia published by John Wiley & Sons Ltd.)

Introduction: Eptacog beta is a new recombinant activated human factor VII bypassing agent approved in the United States for the treatment and control of bleeding in patients with haemophilia A or B with inhibitors 12 years of age or older., Aim: To prospectively assess in a phase 3 clinical trial (PERSEPT 2) eptacog beta efficacy and safety for treatment of bleeding in children <12 years of age with haemophilia A or B with inhibitors., Methods: Using a randomised crossover design, subjects received initial doses of 75 or 225 μg/kg eptacog beta followed by 75 μg/kg dosing at predefined intervals (as determined by clinical response) to treat bleeding episodes (BEs). Treatment success criteria included a haemostasis evaluation of 'excellent' or 'good' without use of additional eptacog beta, alternative haemostatic agent or blood product, and no increase in pain following the first 'excellent' or 'good' assessment., Results: Treatment success proportions in 25 subjects (1-11 years) who experienced 546 mild or moderate BEs were 65% in the 75 μg/kg initial dose regimen (IDR) and 60% in the 225 μg/kg IDR 12 h following initial eptacog beta infusion. By 24 h, the treatment success proportions were 97% for the 75 μg/kg IDR and 98% for the 225 μg/kg IDR. No thrombotic events, allergic reactions, neutralising antibodies or treatment-related adverse events were reported., Conclusion: Both 75 and 225 μg/kg eptacog beta IDRs provided safe and effective treatment and control of bleeding in children <12 years of age., (© 2022 The Authors. Haemophilia published by John Wiley & Sons Ltd.)

Introduction:  FVIII inhibitor development is the most serious contemporary treatment complication in haemophilia A, particularly in previously untreated patients (PUPs). No inhibitors developed in clinical trials in previously treated patients treated with simoctocog alfa (Nuwiq), a fourth-generation recombinant FVIII produced in a human cell line., Methods:  The NuProtect study investigated the immunogenicity of simoctocog alfa in PUPs. NuProtect was a prospective, multinational, open-label, non-controlled, phase III study. PUPs with severe haemophilia A (FVIII:C <1%) of any age and ethnicity were treated with simoctocog alfa for 100 exposure days or a maximum of 5 years. Patients were true PUPs without prior exposure to FVIII concentrates or blood components. Inhibitor titres were measured with the Nijmegen-modified Bethesda assay; cut-off for positivity was 0.6 BU mL -1 (≥0.6 to <5 low-titre, ≥5 high titre)., Results:  A total of 108 PUPs with a median age at first treatment of 12.0 months (interquartile range: 8.0-23.5) were treated with simoctocog alfa. F8 mutation type was known for 102 patients (94.4%) of whom 90 (88.2%) had null F8 mutations and 12 (11.8%) had non-null mutations. Of 105 PUPs evaluable for inhibitor development, 28 (26.7%) developed inhibitors; 17 high titre (16.2%) and 11 low titre (10.5%). No PUPs with non-null F8 mutations developed inhibitors., Conclusion:  In the NuProtect study, the rate of inhibitor development in PUPs with severe haemophilia A treated with simoctocog alfa was lower than the rate reported for hamster-cell-derived recombinant factor VIII products in other recent clinical trials. No inhibitors were reported in PUPs with non-null F8 mutations., Competing Interests: R. J. Liesner, A. Abraham, C. Altisent, M. J. Belletrutti, M. Carcao, M. Carvalho, H. Chambost, A. K. C. Chan, L. Dubey, J. Ducore, M. Gattens, P. Gresele, Y. Gruel, B. Guillet, V. J. Yuste, L. Kitanovski, A. Klukowska, S. Lohade, J. Oldenburg, A. Pavlova, B. Pollio, M. Sigaud, V. Vdovin, K. Vilchevska, J. K. M. Wu and E. J. Neufeld were clinical study investigators for the NuProtect Study (Octapharma-sponsored). R. J. Liesner has received grants/research support from Octapharma, Bayer, Baxalta, Novo Nordisk and Roche, has acted as a consultant for Bayer and Baxalta, and has participated in speaker bureaus for Novo Nordisk, Octapharma and SOBI. A. Abraham has received grants/research support from Novo Nordisk and Roche, and has received support for attending scientific meetings from Novo Nordisk. C. Altisent has been a member of advisory boards and/or speaker bureaus for Baxalta (Shire), Bayer, CSL Behring, Grifols, Octapharma, Novo Nordisk, Pfizer, Roche and SOBI. M. J. Belletrutti has received research support from Octapharma, has acted as a consultant for Roche Canada, Sanofi and Takeda Canada, and has participated in speaker bureaus for Octapharma Canada and Takeda Canada. M. Carcao received research support/grants from Bayer, Novo Nordisk, Pfizer, Sanofi and Takeda, and has participated in speaker bureaus for Bayer, CSL Behring, Grifols, LFB, Novo Nordisk, Octapharma, Pfizer, Roche, Sanofi and Takeda. M. Carvalho has been an investigator on clinical trials sponsored by CSL Behring, Novo Nordisk, Octapharma and Roche, and has received support for attending scientific meetings and honoraria (speaker fees/consultant in advisory boards) for Bayer, Baxalta (Shire), CSL Behring, Novo Nordisk, Octapharma, Pfizer, Siemens, SOBI and Stago. H. Chambost has received research support from CSL Behring, LFB, Novo Nordisk, Octapharma, Roche/Chugaï, Shire/Takeda, SOBI; honoraria from Bayer, LFB, Octapharma, Pfizer, Roche and SOBI. A. K. C. Chan has been an investigator on clinical trials sponsored by Bayer, Biogen, CSL, Novo Nordisk, Octapharma and Shire and has received grants/research support from Bayer and Pfizer, and has participated in advisory boards for Bayer, Biogen, BioMarin, Novo Nordisk and Octapharma. J. Ducore has been an investigator on clinical trials sponsored by Octapharma, CSL Behring, OPKO Biologics, Bayer, Baxalta (Shire), Sparks Therapeutics, Biogen, Pfizer, Genentech (Roche), LFB and RevBio, has provided consultancy services to Octapharma, Bayer, Baxalta (Shire), Biogen and LFB, and is a speaker for Bayer. Y. Gruel has received support for attending scientific meetings and honoraria (speaker fees/consultant in advisory boards) from Baxalta (Shire), Bayer Healthcare, CSL Behring, LFB, Novo Nordisk, Octapharma, Pfizer, Roche and SOBI, has been an investigator in studies sponsored by Biogen, LFB and SOBI, and has received research support from CSL Behring, LFB and Octapharma. B. Guillet has been an investigator on clinical trials, or has received honoraria for speaking/consulting or funds for research from Bayer, CSL Behring, LFB, Novo Nordisk, Octapharma, Roche, SOBI and Takeda/Shire. V. J. Yuste has received reimbursement for attending symposia/congresses and/or honoraria for speaking and/or honoraria for consulting, and/or funds for research from Shire, Bayer, CSL Behring, Grifols, Novo Nordisk, SOBI, Octapharma and Pfizer. A. Klukowska has received personal fees from CSL Behring, Novo Nordisk, Octapharma, Pfizer, Roche, Shire and SOBI. M. E. Mancuso has received speaker and/or consultancy fees from Bayer Healthcare, CSL Behring, Takeda, Octapharma, Roche, Pfizer, Kedrion, Grifols, Novo Nordisk and SOBI. J. Oldenburg has received reimbursement for attending symposia/congresses or honoraria for speaking or honoraria for consulting, or funds for research from Bayer, Biogen Idec, Biotest, Chugai, CSL Behring, Grifols, Novo Nordisk, Octapharma, Pfizer, Roche, Shire and SOBI. A. Pavlova has participated in studies sponsored by Octapharma AG. B. Pollio has received support for attending scientific meetings and honoraria (speaker fees/consultant in advisory boards) from Baxalta (Shire), Bayer Healthcare, CSL Behring, Kedrion, Novo Nordisk, Octapharma, Pfizer and SOBI. M. Sigaud has received reimbursement for attending symposia/congresses, honoraria for speaking or for consulting from Biomarin, CSL Behring, Novo Nordisk, Octapharma, Roche and Shire/Takeda. J. K. M. Wu received funding to attend meetings and has participated in Octapharma-funded clinical research. M. Jansen is a full-time employee of Octapharma GmbH, Vienna, Austria. L. Belyanskaya, O. Walter and S. Knaub are employees of Octapharma AG, Lachen, Switzerland. E. J. Neufeld has received honoraria and participated in advisory boards for Octapharma. He has been a consultant for Genentech and Pfizer, and has participated in advisory boards for Novo Nordisk, Kedrion, Genentech, Baxalta/Shire (now Takeda), Novartis and CSL-Behring during the course of the NuProtect study. He has served on data monitoring committees for Bayer, Acceleron Pharma and ApoPharma (now Chiesi), and received research funding from the American Thrombosis and Hemostasis Network (ATHN). L. Dubey, M. Gattens, P. Gresele, L. Kitanovski, S. Lohade, V. Vdovin and K. Vilchevska declare no competing financial interests., (The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution License, permitting unrestricted use, distribution, and reproduction so long as the original work is properly cited. (https://creativecommons.org/licenses/by/4.0/).)

Introduction: Haemophilia patients with inhibitors often require a bypassing agent (BPA) for bleeding episode management. Eptacog beta (EB) is a new FDA-approved recombinant activated human factor VII BPA for the treatment and control of bleeding in haemophilia A or B patients with inhibitors (≥12 years of age). We describe here the EB safety profile from the three prospective Phase 3 clinical trials performed to date., Aim: To assess EB safety, immunogenicity and thrombotic potential in children and adults who received EB for treatment of bleeding and perioperative care., Methods: Using a randomized crossover design, 27 subjects in PERSEPT 1 (12-54 years) and 25 subjects in PERSEPT 2 (1-11 years) treated bleeding episodes with 75 or 225 μg/kg EB initially followed by 75 μg/kg dosing at predefined intervals as determined by clinical response. Twelve PERSEPT 3 subjects (2-56 years) received an initial preoperative infusion of 75 μg/kg (minor procedures) or 200 μg/kg EB (major surgeries) with subsequent 75 μg/kg doses administered intraoperatively and post-operatively as indicated. Descriptive statistics were used for data analyses., Results: Sixty subjects who received 3388 EB doses in three trials were evaluated. EB was well tolerated, with no allergic, hypersensitivity, anaphylactic or thrombotic events reported and no neutralizing anti-EB antibodies detected. A death occurred during PERSEPT 3 and was determined to be unlikely related to EB treatment by the data monitoring committee., Conclusion: Results from all three Phase 3 trials establish an excellent safety profile of EB in haemophilia A or B patients with inhibitors for treatment of bleeding and perioperative use., (© 2021 The Authors. Haemophilia published by John Wiley & Sons Ltd.)

Introduction: Surgical procedures in persons with haemophilia A or B with inhibitors (PwHABI) require the use of bypassing agents (BPA) and carry a high risk of complications. Historically, only two BPAs have been available; these are reported to have variable responses., Aim: To prospectively evaluate the efficacy and safety of a new bypassing agent, human recombinant factor VIIa (eptacog beta) in elective surgical procedures in PwHABI in a phase 3 clinical trial, PERSEPT 3., Methods: Subjects were administered 200 µg/kg (major procedures) or 75 µg/kg eptacog beta (minor procedures) immediately prior to the initial surgical incision; subsequent 75 µg/kg doses were administered to achieve postoperative haemostasis and wound healing. Efficacy was assessed on a 4-point haemostatic scale during the intra- and postoperative periods. Anti-drug antibodies, thrombotic events and changes in clinical/laboratory parameters were monitored throughout the perioperative period., Results: Twelve subjects underwent six major and six minor procedures. The primary efficacy endpoint success proportion was 100% (95% CI: 47.8%-100%) for minor procedures and 66.7% (95% CI: 22.3%-95.7%) for major procedures; 81.8% (95% CI: 48.2%-97.7%) of the procedures were considered successful using eptacog beta. There was one death due to bleeding from a nonsurgical site; this was assessed as unlikely related to eptacog beta. No thrombotic events or anti-eptacog beta antibodies were reported., Conclusion: Two eptacog beta dosing regimens in PwHABI undergoing major and minor surgical procedures were well-tolerated, and the majority of procedures were successful based on surgeon/investigator assessments. Eptacog beta offers clinicians a new potential therapeutic option for procedures in PwHABI., (© 2021 The Authors. Haemophilia published by John Wiley & Sons Ltd.)

Recent studies suggest outpatient therapy, oral antibiotics, or earlier discharge could be appropriate in some pediatric patients admitted with febrile neutropenia; supporting data are lacking. Retrospective chart review of patients admitted from September 2005 through October 2016 identified 131 "early discharge" febrile neutropenia admissions with discharge absolute neutrophil count (ANC) <500/µl and negative cultures. All were afebrile and discharged without outpatient antibiotics. Eleven of 131 patients (8%) were readmitted. Two patients called back for late positive cultures. Nine were readmitted with febrile neutropenia; 2 had positive cultures on readmission. All 4 patients with positive cultures were safely treated with appropriate antibiotics. The remaining 7 patients had uneventful readmissions. Average ANC (SD) at discharge was lower for patients readmitted versus those not readmitted (69 [70] vs. 196 [145], P≤0.001), as was absolute phagocyte count (APC) at discharge (97 [82] vs. 453 [431], P≤0.001). APC on admission was not significantly lower for those readmitted (165 [254] vs. 321 [388], P=0.09). Few patients required readmission; those with bacterial infections were easily identified and appropriately treated. Higher ANC or APC criteria for discharge would increase length of hospital stay without decreasing morbidity. A subset of patients admitted with febrile neutropenia can be safely discharged before count recovery without oral antibiotics., Competing Interests: The authors declare no conflict of interest., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Objective: To assess leukemia risks among children with Down syndrome in a large, contemporary cohort., Study Design: Retrospective cohort study including 3 905 399 children born 1996-2016 in 7 US healthcare systems or Ontario, Canada, and followed from birth to cancer diagnosis, death, age 15 years, disenrollment, or December 30, 2016. Down syndrome was identified using International Classification of Diseases, Ninth and Tenth Revisions, diagnosis codes. Cancer diagnoses were identified through linkages to tumor registries. Incidence and hazard ratios (HRs) of leukemia were estimated for children with Down syndrome and other children adjusting for health system, child's age at diagnosis, birth year, and sex., Results: Leukemia was diagnosed in 124 of 4401 children with Down syndrome and 1941 of 3 900 998 other children. In children with Down syndrome, the cumulative incidence of acute myeloid leukemia (AML) was 1405/100 000 (95% CI 1076-1806) at age 4 years and unchanged at age 14 years. The cumulative incidence of acute lymphoid leukemia in children with Down syndrome was 1059/100 000 (95% CI 755-1451) at age 4 and 1714/100 000 (95% CI 1264-2276) at age 14 years. Children with Down syndrome had a greater risk of AML before age 5 years than other children (HR 399, 95% CI 281-566). Largest HRs were for megakaryoblastic leukemia before age 5 years (HR 1500, 95% CI 555-4070). Children with Down syndrome had a greater risk of acute lymphoid leukemia than other children regardless of age (<5 years: HR 28, 95% CI 20-40, ≥5 years HR 21, 95% CI 12-38)., Conclusions: Down syndrome remains a strong risk factor for childhood leukemia, and associations with AML are stronger than previously reported., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Introduction: Ensuring hemostasis during invasive procedures is a challenge in patients with severe hemophilia A. This analysis evaluated efficacy and safety of BAY 94-9027, an extended-half-life recombinant factor VIII (FVIII), in the surgical setting., Materials and Methods: Patients participating in an open-label BAY 94-9027 clinical trial who underwent major surgery were included in the analysis. Investigator/surgeon assessment of hemostasis during surgery was the primary outcome. In addition, information about FVIII use, FVIII levels during perioperative period, bleeding complications and FVIII inhibitor development were collected., Results: Data were analyzed for 26 major surgeries (orthopedic, n = 21) in 20 patients aged 13-61 years. BAY 94-9027 provided effective hemostasis during all procedures. FVIII levels 6-8 h post preoperative infusion and prior to the first follow-up infusion were in the range expected to maintain protection in the major surgery setting. The median time from preoperative infusion to the first follow-up infusion (the first infusion administered after the preoperative infusion) was 12.33 (3.6-49.9) h. No intraoperative bleeding complications occurred, and no new inhibitors developed following any surgery., Conclusions: The results of the study demonstrate that BAY 94-9027 was efficacious and well tolerated in the treatment of patients undergoing major surgeries. Advantages of BAY 94-9027 include the potential for less frequent infusion and reduced factor consumption, which should simplify the management of patients during major surgery., (Copyright © 2019 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Primary renal lymphoma is a rare entity, even more so in children. Children with primary renal lymphoma present with variable clinical features such as constitutional signs and symptoms, acute kidney injury, palpable abdominal masses, and gross hematuria. Herein we report a child who presented with seemingly advanced chronic kidney disease and was eventually diagnosed with primary lymphoma. He responded well to intensive chemotherapy and recovered renal function, although he was left with some functional limitations as a consequence of his treatment regimen. Our report highlights the importance of keeping neoplastic conditions under consideration when taking care of children with severe kidney disease of unclear etiology.

Perioperative clotting factor replacement is administered to reverse the inherent haemostatic defect in persons with haemophilia (PWH), potentially increasing their risk for developing venous thromboembolism (VTE) postoperatively. It was our objective to determine the prevalence of VTE in PWH undergoing total hip or knee arthroplasty (THA, TKA). Patients with haemophilia A or B who underwent THA or TKA were enrolled in this prospective, multicentre observational cohort study. Lower extremity venous duplex ultrasound was performed prior to surgery and 4-6 weeks after surgery. Eleven centres enrolled 51 subjects, 46 of whom completed the study. Six subjects (13.0 %) were treated with bypass agents perioperatively; the remaining 40 subjects received factor VIII or IX replacement. Intermittent pneumatic compression devices were utilised postoperatively in 23 subjects (50 %), and four subjects (8.7 %) also received low-molecular-weight heparin prophylaxis. One subject (2.2 %) with moderate haemophilia A was diagnosed with symptomatic distal deep-vein thrombosis (DVT) on day 6 following TKA. One subject (2.2 %) with severe haemophilia A was diagnosed with pulmonary embolism on day 9 following bilateral TKA. No subjects had asymptomatic DVT. Eighteen subjects (39.1 %) had major bleeding, and three subjects (6.5 %) experienced minor bleeding. The observed prevalence of ultrasound-detectable, asymptomatic DVT in PWH following TKA or THA in this study was low, but the incidence of symptomatic VTE (4.3 %, 95 % CI, 0.5-14.8 %) appeared similar to the estimated incidence in the general population without thromboprophylaxis.

Cast nephropathy is the most common manifestation of renal injury in patients with multiple myeloma but is rarely reported in other conditions. We are reporting our experience in caring for a teenager with a metastatic neuroendocrine carcinoma who developed rapidly progressive kidney injury that advanced to end-stage renal disease. On renal biopsy extensive tubular necrosis and intratubular eosinophilic casts were noted. This previously unreported finding should prompt oncologists to closely monitor for such a complication in patients with secretory tumors. Whether early plasmapheresis could be of benefit, as has been tried in multiple myeloma, remains to be determined.

We evaluated the relationship between the risk of childhood acute lymphoblastic leukemia (ALL) and the levels of metals in carpet dust. A dust sample was collected from the homes of 142 ALL cases and 187 controls participating in the California Childhood Leukemia Study using a high volume small surface sampler (2001-2006). Samples were analyzed using microwave-assisted acid digestion in combination with inductively coupled plasma mass spectrometry for arsenic, cadmium, chromium, copper, lead, nickel, tin, tungsten, and zinc. Eight metals were detected in at least 85% of the case and control homes; tungsten was detected in <15% of homes. Relationships between dust metal loadings (μg metal per m(2) carpet) and ALL risk were modeled using multivariable logistic regression, adjusting for the child's age, sex, and race/ethnicity and confounders, including household annual income. A doubling of dust metal loadings was not associated with significant changes in ALL risk (odds ratio (95% confidence interval): arsenic: 0.96 (0.86, 1.07), cadmium: 0.92 (0.81, 1.05), chromium: 1.01 (0.90, 1.14), copper: 0.97 (0.91, 1.03), lead: 1.01 (0.93, 1.10), nickel: 0.95 (0.82, 1.09), tin: 0.96 (0.86, 1.08), and zinc: 0.94 (0.84, 1.05)). Our findings do not support the hypothesis that metals in carpet dust are risk factors for childhood ALL.

Although Wilms tumor is the most common renal malignancy in children, the differential diagnosis is extensive and includes both malignant and benign disorders. We present a simple mnemonic-WARM N COLD, to aid in remembering these diverse tumors. Imaging clues including age of the patient, associated disease or syndrome as well as salient imaging characteristics such as bilaterality, and type or presence of metastasis are also presented and can help differentiate between these renal tumors of childhood.

Background: Tobacco smoke contains carcinogens known to damage somatic and germ cells. We investigated the effect of tobacco smoke on the risk of childhood acute lymphoblastic leukemia (ALL) and myeloid leukemia (AML), especially subtypes of prenatal origin such as ALL with translocation t(12;21) or high-hyperdiploidy (51-67 chromosomes)., Methods: We collected information on exposures to tobacco smoking before conception, during pregnancy, and after birth in 767 ALL cases, 135 AML cases, and 1,139 controls (1996-2008). Among cases, chromosome translocations, deletions, or aneuploidy were identified by conventional karyotype and fluorescence in situ hybridization., Results: Multivariable regression analyses for ALL and AML overall showed no definite evidence of associations with self-reported (yes/no) parental prenatal active smoking and child's passive smoking. However, children with history of paternal prenatal smoking combined with postnatal passive smoking had a 1.5-fold increased risk of ALL [95% confidence interval (CI), 1.01-2.23], compared to those without smoking history (ORs for pre- or postnatal smoking only were close to one). This joint effect was seen for B-cell precursor ALL with t(12;21) (OR = 2.08; 95% CI, 1.04-4.16), but not high hyperdiploid B-cell ALL. Similarly, child's passive smoking was associated with an elevated risk of AML with chromosome structural changes (OR = 2.76; 95% CI, 1.01-7.58), but not aneuploidy., Conclusions: Our data suggest that exposure to tobacco smoking was associated with increased risks of childhood ALL and AML; and risks varied by timing of exposure (before and/or after birth) and cytogenetic subtype, based on imprecise estimates., Impact: Parents should limit exposures to tobacco smoke before and after the child's birth.

We report a child with thrombotic thrombocytopenic purpura (TTP) secondary to systemic lupus erythematosus. The diagnosis was confirmed by low ADAMTS13 activity (<5%) along with the presence of a low titer inhibitor. Her clinical course was complicated by systemic lupus erythematosus, immunosuppressant therapy, and septic shock. She responded to plasma exchange and ADAMTS13 activity levels recovered. This case illustrates the heterogeneity of TTP and the difficulty of making a diagnosis of TTP. ADAMTS13 activity assay can be useful in the differential diagnosis of diseases with clinical features of thrombotic microangiopathy in pediatric patients. However, treatment needs to be decided carefully case-by-case.

Background: The association between diagnostic X-ray exposures early in life and increased risk of childhood leukaemia remains unclear., Methods: This case-control study included children aged 0-14 years diagnosed with acute lymphoid leukaemia (ALL, n = 711) or acute myeloid leukaemia (AML, n = 116) from 1995 to 2008. Controls were randomly selected from the California birth registry and individually matched to cases with respect to date of birth, sex, Hispanic ethnicity and maternal race. Conditional logistic regression analyses were performed to assess whether ALL or AML was associated with self-reported child's X-rays after birth (post-natal), including number of X-rays, region of the body X-rayed and age at first X-ray, as well as maternal X-rays before and during pregnancy (preconception and prenatal)., Results: After excluding X-rays in the year prior to diagnosis (reference date for matched controls), risk of ALL was elevated in children exposed to three or more post-natal X-rays [odds ratio (OR) = 1.85, 95% confidence interval (CI) 1.12-2.79]. For B-cell ALL specifically, any exposure (one or more X-rays) conferred increased risk (OR = 1.40, 95% CI 1.06-1.86). Region of the body exposed was not an independent risk factor in multivariable analyses. No associations were observed between number of post-natal X-rays and AML (OR = 1.05, 95% CI 0.90-1.22) or T-cell ALL (OR = 0.84, 95% CI 0.59-1.19). Prevalence of exposure to prenatal and preconception X-rays was low, and no associations with ALL or AML were observed., Conclusions: The results suggest that exposure to post-natal diagnostic X-rays is associated with increased risk of childhood ALL, specifically B-cell ALL, but not AML or T-cell ALL. Given the imprecise measures of self-reported X-ray exposure, the results of this analysis should be interpreted with caution and warrant further investigation.

We investigated obesity [body mass index (BMI) >95th percentile] and being heavy (BMI >85th percentile) in 95 children in first remission more than 2 years after treatment for acute lymphoblastic leukemia or non-Hodgkin lymphoma seen at our institution. Height, weight and BMI at diagnosis, end of treatment and follow-up, and blood pressure at diagnosis were adjusted by z-score for age and sex. At follow-up, obesity and overweight were not more prevalent than in the general population. Median BMI z-scores rose significantly between diagnosis (0.38) and treatment end (0.62) but not during follow-up (0.70). Median weight z-scores rose significantly during both periods (diagnosis 0.23, treatment end 0.49, and follow-up 0.68). Median height z-scores were 0.51, 0.14, and 0.16 for the same 3 time points, respectively. Repeated measures, multivariate logistic regression identified Hispanic ethnicity, younger age at diagnosis, and a positive age:weight interaction as being associated with obesity and being heavy at follow-up. There was no association with diagnosis, sex, age alone, radiation dose or field, metabolic diagnosis in patient/family, height z-score at diagnosis, duration of treatment, and systolic or diastolic blood pressure. Obesity and overweight were a combination of weight gain and height loss during treatment although weight continued to increase after treatment. We did not identify disease-related parameters associated with these effects.

New lesions that occur while patients are receiving treatment for malignant tumors may represent not only difficulties in arriving at the correct diagnosis, but also impact on subsequent therapeutic options. We encountered a patient developing new pulmonary lesions during and after receiving treatment for Stage II Wilms tumor (WT). The presence of mature rhabdomyoblasts in multiple biopsy specimens allowed rational decisions to be made regarding subsequent therapy. This and other published experiences suggest that patients with WT may develop choristomas or have tumors, which undergo cytodifferentiation. Methodologies are now available allowing differentiation of these two processes.

Purpose: To investigate the prognostic significance of surveillance neuroimaging for detection of relapse among children with malignant brain tumors., Patients and Methods: A historical cohort study examined all children who experienced relapse from 1985 to 1999 on one of 10 Pediatric Oncology Group trials for malignant glioma, medulloblastoma, or ependymoma., Results: For all 291 patients (median age at diagnosis, 8.2 years), median time to first relapse was 8.8 months (range, 0.6 to 115.6 months). Ninety-nine relapses were radiographic, and 192, clinical; median time to relapse was 15.7 versus 6.6 months, respectively (P = .0001). When stratified by pathology, radiographic and clinical groups showed differences in median time to relapse for malignant glioma (7.8 v 4.3 months, respectively; P = .041) and medulloblastoma (23.6 v 8.9 months, respectively; P = .0006) but not ependymoma (19.5 v 13.3 months, respectively; P = .19). When stratified by early (< 8.8 months) or late (> or = 8.8 months) time to relapse, 115 early relapses were clinical, and 32, radiographic; for late relapses, 77 were clinical, and 67, radiographic (P = .001). Overall survival (OS) from relapse was significantly longer for radiographic compared with clinical detection (median, 10.8 months; 1-year OS, 46% v median, 5.5 months; 1-year OS, 33%; P = .002), but this trend did not retain significance when analyzed by pathology subgroups., Conclusion: Surveillance neuroimaging detects a proportion of asymptomatic relapses, particularly late relapses, and may provide lead time for other therapies on investigational trials. During the first year after diagnosis, radiographic detection of asymptomatic relapse was infrequent. A prospective study is needed to formulate a rational surveillance schedule based on the biologic behavior of these tumors.

Purpose: Children with recurrent or progressive central nervous system (CNS) tumors have an unfavorable prognosis. Based on Pediatric Oncology Group (POG) institutional pilot data, low-dose oral methotrexate (MTX) was studied., Methods: Eight dosages of MTX 7.5 mg/m2 every 6 hours were administered on a weekly schedule for as long as 18 months. Patients in six different brain tumor strata were accrued., Results: The response rates (complete or partial responses) were as follows: astrocytoma 2 of 10, malignant glioma 1 of 19, medulloblastoma 0 of 18, brainstem tumor 0 of 12, ependymoma 1 of 7, and miscellaneous histologic types 0 of 12. The main toxicities, mucositis, myelosuppression, and hepatic transaminase elevation were considered tolerable., Conclusion: Low-dose oral MTX showed no significant activity against malignant glioma, medulloblastoma, brainstem tumors, and miscellaneous histologic types. Indeterminate but low response rates were observed in children with astrocytoma and ependymoma. This regimen will not be recommended for front-line therapy.

The respiratory epithelium is often exposed to oxidant gases, including ozone from photochemical smog and toxic oxygen metabolites released from neutrophils recruited in conditions of airway inflammation. We evaluated DNA single strand break formation by alkaline elution as a measure of oxidant-induced DNA damage to bronchial epithelial cells. Human AdenoSV-40-transformed bronchial epithelial cells (BEAS), subclone R1.4 or nonhuman primate bronchial epithelial cells were cultured in growth factor supplemented Ham's F12 medium on polycarbonate filters. DNA was labeled by incubation with [3H]thymidine. Cells were incubated for 1 h in HBSS or HBSS and increasing concentrations of hydrogen peroxide (H2O2). Cells incubated in H2O2 demonstrated dose-dependent increases in strand break formation, and BEAS cells were more sensitive to H2O2-induced injury than primary bronchial epithelial cells. The addition of catalase or preincubation of cells with the iron chelator desferoxamine prevented H2O2-induced strand breakage. DNA strand break formation may be an important mechanism of oxidant injury in respiratory epithelial cells.

The cytotoxicity of bifunctional alkylating agents is generally attributed to DNA damage, especially DNA-DNA crosslinking activity. It is unclear how crosslinks or other cellular damage result in cell death. Studies of drug effects at the level of expression of specific gene products may help elucidate the mechanism of cell killing. We examined proteins synthesized in L-phenylalanine mustard treated human lymphoma cells by [35S]methionine labeling and SDS-PAGE. Drug-treated cells showed decreased labeling of proteins in two molecular weight bands of 17 kDa (a doublet) and 12 kDa at 6, 18 and 24 hours after drug removal. One of the components of the 17 kDa doublet has been identified as calmodulin, a calcium binding protein essential to cell cycle progression and survival.

In June 1984, the Pediatric Oncology Group (POG) initiated a pilot study (8498) using high-dose cytarabine (HdA; 3 g/m2) for intensification of early therapy in childhood acute myelogenous leukemia (AML) (group I). Remission induction therapy consisted of two courses of daunorubicin, cytarabine (Ara-C), and thioguanine (DAT). Postremission therapy consisted of four sequential courses, each consisting of (1) four doses of HdA (HdA4) followed by asparaginase (L-Asp), (2) etoposide (VP) plus azacytidine (Az), (3) prednisone, vincristine, methotrexate, and mercaptopurine (POMP), and (4) Ara-C daily for 5 days by continuous infusion. Six doses of intrathecal Ara-C were given for CNS prophylaxis. In December 1986, the protocol was amended (group II) to substitute six doses of HdA (HdA6) for the second DAT (two + five) induction course; postinduction, a single course of HdA6 was given instead of four HdA/L-Asp courses, and the remainder of the therapy was unchanged. One hundred forty group I patients and 145 group II patients were assessable. The two groups were similar with regard to clinical prognostic groups. No significant differences were noted in the two groups with regard to remission induction (85% [SE = 2%] in each group), induction deaths (6.5% v 7.0%), or deaths in remission (one in each group). Cerebellar toxicity was reported in three patients in group II (with HdA6) but none in group I (HdA4). At present, patients who received HdA6 (group II) had higher event-free survival than patients in group I (EFS at 3 years, 34% [SE = 11%] v 29% [SE = 4%]), and disease-free survival (DFS at 3 years, 42% [SE = 14%] v 34% [SE = 4%]), but the differences were not statistically significant. In both groups, children less than 2 years and those with WBCs less than 100,000/microL had significantly better outcome (EFS of 55% [SE = 10%] and 36% [SE = 5%] at 3 years, respectively) than children greater than or equal to 2 years and those with WBCs greater than or equal to 100,000/microL (EFS of 27% [SE = 5%] and 20% [SE = 9%] at 3 years, respectively.

We reviewed the records of all patients with a diagnosis of ALL made at our center during a 13-year period to determine the relationship between bone pain and the hematologic findings at diagnosis of acute lymphoblastic leukemia. Of 296 eligible patients, 179 (60%) had no bone pain (group 1), 65 (22%) had some bone pain (group 2), and 52 (18%) had prominent bone pain that overshadowed other manifestations of the leukemia (group 3). Statistically significant differences were found between the groups for hemoglobin concentration (p less than 0.001), leukocyte count (p = 0.014), absolute neutrophil count (p = 0.002), percentage of circulating blast cells (p = 0.009), and platelet count (p less than 0.001). Children in group 3 had values closer to normal for all these values than those of patients in the other groups. Group 3 patients had symptoms an average of more than 2 weeks longer before diagnosis, and had significantly lower serum uric acid and higher calcium levels than patients in the other groups had. No differences were detected among the groups in age at diagnosis, gender, or survival rate. We conclude that children with acute lymphoblastic leukemia who have prominent bone pain preceding the diagnosis frequently have nearly normal hematologic values and that this feature may contribute to a delay in diagnosis.

Procarbazine, a chemotherapeutic hydrazine, is thought to be metabolized to an alkylating species similar to methyl carbonium ion by multistep reactions involving cytochrome P-450, monoamine oxidase, and cytosolic enzymes. The DNA-damaging and cytotoxic potential of procarbazine and its metabolites in murine L1210 leukemia tumor cells in vitro was determined using alkaline elution techniques and extrapolation of growth curves. Neither procarbazine nor any of the chemical degradation products (except for the aldehyde derivative at high concentrations) caused significant amounts of DNA strand breakage. The primary enzymatic oxidation product, azo-procarbazine, did not produce strand breakage. However, exposure of the cells to either of the two isomers of azoxy-procarbazine led to significant DNA damage and cytotoxicity. DNA damage included both single-strand breaks and alkali-labile sites. At equimolar concentrations, the azoxy 2 isomer of procarbazine caused 14 to 20 times more DNA damage than did the azoxy 1 metabolite. When cell growth is expressed as percentage survival of L1210 cells, the azoxy 2 isomer was approximately 7-fold more toxic than the azoxy 1 metabolite. The other metabolites tested showed little or no cytotoxicity. L1210 cells were shown to contain little or no cytochrome P-450 or monoamine oxidase activity, which may account for the lack of toxicity of the parent drug or the primary oxidative metabolite, azo-PCZ, to these cells. The conversion of procarbazine to the azoxy-procarbazine isomers in vivo must occur in cells which contain these enzymes, such as liver. However, the azoxy isomers of procarbazine were metabolized in L1210 cells, presumably leading to the DNA or cytotoxic damage observed.

Hoechst 33258 fluorescence of single stranded DNA has been used to perform alkaline elution with unlabeled DNA. The high background fluorescence of "standard" elution solutions has prompted others to use EDTA but the elution characteristics of DNA in EDTA-containing solutions and the comparability of results with those using "standard" tetrapropyl ammonium hydroxide solutions have not previously been examined. We report here the elution characteristics of DNA in EDTA and the relevant parameters for the successful use of EDTA as an elution solution. An increase in elution pH to 12.4 is required but elution solutions of higher pH cause alkaline hydrolysis of undamaged DNA. Drug-treated DNA from which DNA-protein crosslinks have been removed can be completely removed from the filters at the end of the elution by a Pronase filter digestion. The simplest and most efficient removal of DNA-protein crosslinks is through the inclusion of proteinase-K in an SDS containing lysis solution. EDTA elution can measure interstrand crosslinks and single strand breaks as easily as is performed using radiolabeled DNA under "standard" elution conditions and requires only 1.5-2 x 10(6) cells per elution filter. DNA-protein crosslinking measurements were unsatisfactory, however, since even the Pronase digestion failed to completely remove protein-crosslinked DNA from the elution filters.

The human Burkitt's lymphoma cell line BHM fails to show synergistic killing by alkylating agents in the presence of theophylline. Nitrosoureas (BCNU and CNU), a mustard agent (L-phenylalanine mustard), and a platinum coordination complex (cis-diamminedichloroplatinum-II) did not show increased cytotoxicity when cells were treated in the presence of theophylline. Despite varying abilities of the drugs to induce DNA damage in BHM cells (no DNA interstrand cross-linking with nitrosoureas or platinum and significant interstrand cross-linking following L-PAM treatment) theophylline did not alter the pattern of DNA damage. DNA interstrand cross-linking following treatment by L-PAM with theophylline was slightly decreased from that seen with L-PAM alone. All three drugs induced DNA replicon initiation inhibition in BHM cells as measured both by alkaline sucrose gradient sedimentation and pH step alkaline elution. As opposed to cell lines where methylxanthines increase alkylating agent cytotoxicity, theophylline and caffeine failed to reverse the drug-induced replicon initiation inhibition seen in BHM cells. These findings support the hypothesis that the synergistic killing seen in some cell lines with alkylating agents and methylxanthines is due to the reversal of replicon initiation inhibition by the methylxanthines.

The excision repair of solar uv-induced nondimer DNA damage was examined in ICR 2A frog cells through the use of the bromodeoxyuridine (BrdUrd) photolysis assay. A relatively pure population of nondimer DNA photoproducts was induced by irradiation of ICR 2A cells with the Mylar-filtered solar ultraviolet (uv) wavelengths produced by a fluorescent sunlamp followed by exposure to photoreactivating light (PRL) which removes most of the small yield of pyrimidine dimers induced by this treatment. Cultures of cells were also exposed to 254 nm uv, which induces primarily dimers, and 60Co gamma rays. Through use of a modification of the BrdUrd photolysis assay possessing enhanced sensitivity, it was found that the solar uv-induced nondimer DNA damage was repaired by a short patch repair mechanism in which less than approximately 20 nucleotides are inserted into a repaired region. Similar results were also obtained for gamma-irradiated cells. In contrast, excision repair of 254-nm-induced dimers was accomplished by a long-patch process in which an average of about 180 nucleotides are inserted into the repaired sites.

Treatment of acquired aplastic anemia with androgens has been occasionally associated with the development of hepatic tumors. We have studied a 13-year-old boy with idiopathic aplastic anemia in whom oxymetholone treatment was associated with a partial hematological remission. Thirty-four months later, however, the patient developed multiple hepatic tumors. When oxymetholone therapy was discontinued, the aplastic anemia relapsed. He then underwent bone marrow transplantation from his HLA-A, B, and D-compatible sibling. This was followed by hematological and immunological reconstitution. The hepatic tumors underwent progressive regression after bone marrow transplantation. The patient is now 3 years post-bone marrow transplantation and is in complete remission of his aplastic anemia with no evidence of detectable liver tumors.

The excision repair of nondimer DNA damages induced in normal human skin fibroblasts exposed to the Mylar-filtered UV produced by a fluorescent sunlamp was investigated. This work was accomplished through the development of a modification of the bromodeoxyuridine photolysis assay that greatly increases the sensitivity of this assay. This enhancement in sensitivity was achieved through use of alkaline elution to measure the DNA strand breakage produced by the photolysis of bromodeoxyuridine incorporated into the DNA through excision repair. Using this modified bromodeoxyuridine photolysis assay, it was found that the solar UV-induced nondimer DNA damages appear to have been repaired by a short patch repair mechanism in which a small number of nucleotides (two to four) were inserted into the repaired site. This is in contrast to the long patch repair process involved in the excision of cyclobutane pyrimidine dimers in which approximately 40 nucleotides were inserted into each repaired region.

Normal human skin fibroblasts were exposed to either 0-5 J/m2 of 254-nm ultraviolet (UV) radiation or 0-50 kJ/m2 of the Mylar-filtered UV (greater than 310 nm) produced by a fluorescent sunlamp. These cells were then incubated for 0-20 min in medium containing 10 mM hydroxyurea (HU) and 0.1 mM 1-beta-D-arabinofuranosyl cytosine (ara C), and the yield of DNA strand breaks was measured by means of the alkaline elution technique. For cells irradiated with 254-nm UV, which results primarily in the formation of cyclobutane pyrimidine dimers, a rapid increase in DNA strand breaks was detected following incubation with these metabolic inhibitors. In contrast, only a low level of strand breaks formed in cells incubated with HU and ara C after irradiation with approximately equitoxic fluences of sunlamp UV greater than 310 nm, which mainly causes the induction of nondimer DNA lesions. Hence, these results are consistent with the conclusion that the pathways involved in the repair of nondimer DNA damages induced by UV wavelengths greater than 310 nm differ from the repair of pyrimidine dimers.

The present study investigated the mechanism by which theophylline decreases cis-diamminedichloroplatinum(II) (DDP)-induced DNA crosslinking in L1210 cells. Alkaline elution of DNA from L1210 cells treated with DDP in the presence and absence of 1 mM theophylline showed that theophylline decreased interstrand crosslinking by 20%. DNA-protein crosslinking (PXL) immediately following platinum removal (used as a measure of active drug delivered to the cell nucleus) was not altered by theophylline nor were the kinetics of either DNA interstrand (ISC) or DNA-protein crosslink formation after DDP treatment changed by the presence of theophylline. Peak protein crosslinking occurred 6 hr and peak interstrand crosslinking occurred 12 hr after DDP removal. We measured crosslink removal by using thiourea to block the conversion of platinum monoadducts to crosslinks. DNA-protein crosslinks were removed more rapidly in the presence of theophylline. There was no change in interstrand crosslink removal rate when theophylline was present. We conclude that the addition of theophylline to DDP treatment results in decreased amounts of DNA interstrand crosslinking most likely by increasing the removal of DPP-DNA monoadducts. This latter process may be reflected by the increased removal rates for DNA-protein crosslinks.

We investigated the cytotoxic effects of nitrosoureas with and without a 42-hr preincubation with the ornithine decarboxylase (EC 4.1.1.17) inhibitor alpha-difluoromethylornithine (DFMO, 1 mM) in a MER+ (methylation excision repair positive) human cell line. DFMO combined with a chloroethyl nitrosourea [1,3-bis-(2-chloroethyl)-1-nitrosourea (BCNU) or 1-(2-chloroethyl)-1-nitrosourea (CNU)] yielded increased toxicity with D37 ratios of 1.9 and 3.3 respectively. There was no enhanced toxicity with the monofunctional nitrosourea 1-ethyl-1-nitrosourea (ENU). BCNU or CNU did not induce DNA-DNA interstrand crosslinks in cells with or without a DFMO pretreatment. DNA single-strand breakage was not increased by addition of DFMO. BCNU-induced DNA-protein crosslinking was decreased in cells pretreated with DFMO. These findings are similar to those in MER- cells in that the chloroethyl carbonium alkylating species is required for the enhanced cytotoxicity seen with DFMO. The ability to form DNA interstrand crosslinks, however, does not appear to be necessary for this toxicity enhancement.

Two adolescents with acute lymphoblastic leukemia developed acute psychotic episodes shortly after induction therapy, which included prednisone, was begun. Symptoms included regressive behavior, incontinence, fluctuating levels of activity, and delusions. Both patients regained normal mental status after a number of weeks. Treatment included tapering of steroid dosage, introduction of a highly structured environment, and early use of chlorpromazine. Psychosis persisted beyond discontinuation of steroid therapy, but both patients subsequently received steroids after return of normal mentation, and in neither did psychosis recur.