Different subtypes of chronic fatigue in childhood cancer survivors: A DCCSS LATER study.

INTRODUCTION: The aim of the current study was to investigate whether subtypes of chronic fatigue (CF) can be identified in childhood cancer survivors (CCS), and if so, to determine the characteristics of participants with a specific subtype. METHODS: Participants were included from the nationwide DCCSS LATER cohort. The Checklist Individual Strength (CIS) was completed to assess fatigue. Participants with CF (scored ≥35 on the fatigue severity subscale and indicated to suffer from fatigue for ≥6 months) were divided into subgroups using two-step cluster analysis based on the CIS concentration, motivation, and physical activity subscales. Differences between groups on demographics, psychosocial, lifestyle, and treatment-related variables were determined using ANOVA and chi-square analyses (univariable) and multinomial regression analysis (multivariable). RESULTS: A total of 1910 participants participated in the current study (n = 450 with CF; n = 1460 without CF). Three CF subgroups were identified: Subgroup 1 (n = 133, 29% of participants) had CF with problems in physical activity; Subgroup 2 (n = 111, 25% of participants) had CF with difficulty concentrating; and Subgroup 3 (n = 206, 46% of participants) had multi-dimensional CF. Compared to Subgroup 1, Subgroup 2 more often reported sleep problems, limitations in social functioning, and less often have more than two comorbidities. Subgroup 3 more often reported depression, sleep problems, a lower self-esteem, and limitations in social functioning and a lower educational level compared to Subgroup 1. CONCLUSION: Different subgroups of CCS with CF can be identified based on fatigue dimensions physical activity, motivation and concentration. Results suggest that different intervention strategies, tailored for each subgroup, might be beneficial.

Gastrointestinal mucositis: a sign of a (systemic) inflammatory response.

PURPOSE OF REVIEW: Gastrointestinal mucositis (GIM) is a significant complication of cancer therapy. Whilst inflammation is a central feature of GIM, studies attempting to mitigate mucosal damage via this mechanism are scarce. This review describes the relation between GIM, local and systemic inflammation, and the microbiome and its metabolites, and explores recent research on therapeutics that target this relationship. RECENT FINDINGS: Recent literature underscores the pivotal role of inflammation in GIM, elucidating its bidirectional relation with disturbance of the gut microbiota composition and intestinal permeability. These events cause a heightened risk of bloodstream infections and lead to systemic inflammation. While studies investigating risk prediction models or therapeutics targeting GIM-related inflammation remain scarce, results have shown promise in finding biomarkers and alleviating GIM and its accompanying clinical symptoms. SUMMARY: The findings underscore the important role of inflammation and the microbiome in GIM. Understanding the inflammatory pathways driving GIM is crucial for developing effective treatments. Further research is needed using genomics, epigenomics, and microbiomics to explore better risk prediction models or therapeutic strategies aimed at mitigating GIM-related inflammation.

Risk factors for Nocardia infection among allogeneic hematopoietic cell transplant recipients: A case-control study of the Infectious Diseases Working Party of the European Society for Blood and Marrow Transplantation.

OBJECTIVES: Nocardiosis is a rare but life-threatening infection after hematopoietic cell transplantation (HCT). We aimed at identifying risk factors for nocardiosis after allogeneic HCT and clarifying the effect of trimethoprim-sulfamethoxazole prophylaxis on its occurrence. METHODS: We performed a retrospective multicenter case-control study of patients diagnosed with nocardiosis after allogeneic HCT between January 2000 and December 2018. For each case, two controls were matched by center, transplant date, and age group. Multivariable analysis was conducted using conditional logistic regression to identify potential risk factors for nocardiosis. Kaplan-Meier survival curves of cases and controls were compared using log-rank tests. RESULTS: Sixty-four cases and 128 controls were included. Nocardiosis occurred at a median of 9 months after allogeneic HCT (interquartile range: 5-18). After adjustment for potential confounders in a multivariable model, Nocardia infection was associated with tacrolimus use (adjusted odds ratio [aOR] 9.9, 95 % confidence interval [95 % CI]: 1.6-62.7), lymphocyte count < 500/µL (aOR 8.9, 95 % CI: 2.3-34.7), male sex (aOR 8.1, 95 % CI: 2.1-31.5), recent use of systemic corticosteroids (aOR 7.9, 95 % CI: 2.2-28.2), and recent CMV infection (aOR 4.3, 95 % CI: 1.2-15.9). Conversely, use of trimethoprim-sulfamethoxazole prophylaxis was associated with a significantly decreased risk of nocardiosis (aOR 0.2, 95 % CI: 0.1-0.8). HCT recipients who developed nocardiosis had a significantly decreased survival, as compared with controls (12-month survival: 58 % and 90 %, respectively; p < 0.0001). CONCLUSIONS: We identified six factors independently associated with the occurrence of nocardiosis among allogeneic HCT recipients. In particular, trimethoprim-sulfamethoxazole prophylaxis was found to protect against nocardiosis.

Unhealthy lifestyle behaviors, overweight, and obesity among childhood cancer survivors in the Netherlands: A DCCSS LATER study.

BACKGROUND: The objective of this study was to examine the prevalence of unhealthy lifestyle behaviors, overweight, and obesity in Dutch childhood cancer survivors (CCSs) compared with sibling controls and the Dutch general population. Other aims were to assess associated factors of unhealthy lifestyle behaviors, overweight, and obesity and to identify subgroups of CCSs at risk for these unhealthy statuses. METHODS: The authors included 2253 CCSs and 906 siblings from the Dutch Childhood Cancer Survivor Study-Late Effects After Childhood Cancer cohort, part 1, and added data from the Dutch general population. Questionnaire data were collected on overweight and obesity (body mass index >25.0 kg/m2), meeting physical activity guidelines (>150 minutes per week of moderate or vigorous exercises), excessive alcohol consumption (>14 and >21 alcoholic consumptions per week for women and men, respectively), daily smoking, and monthly drug use. Multivariable logistic regression analyses and two-step cluster analyses were performed to examine sociodemographic-related, health-related, cancer-related, and treatment-related associated factors of unhealthy lifestyle behaviors and to identify subgroups of CCSs at risk for multiple unhealthy behaviors. RESULTS: CCSs more often did not meet physical activity guidelines than their siblings (30.0% vs. 19.3%; p < .001). Married as marital status, lower education level, nonstudent status, and comorbidities were common associated factors for a body mass index ≥25.0 kg/m2 and insufficient physical activity, whereas male sex and lower education were shared associated factors for excessive alcohol consumption, daily smoking, and monthly drug use. A subgroup of CCSs was identified as excessive alcohol consumers, daily smokers, and monthly drug users. CONCLUSIONS: The current results emphasize the factors associated with unhealthy behaviors and the potential identification of CCSs who exhibit multiple unhealthy lifestyle behaviors.

Listeria monocytogenes Infections in Hematopoietic Cell Transplantation Recipients: Clinical Manifestations and Risk Factors. A Multinational Retrospective Case-Control Study from the Infectious Diseases Working Party of the European Society for Blood and Marrow Transplantation.

Listeriosis is rare after hematopoietic stem cell transplantation (HCT). Little is known about listeriosis in this population. In this retrospective international case-control study, we evaluated 41 listeriosis episodes occurring between 2000 and 2021 in HCT recipients (111 transplant centers in 30 countries) and assessed risk factors for listeriosis by comparisons with matched controls. The 41 listeriosis episodes (all due to Listeria monocytogenes [LM]) occurred in 30 allogeneic (allo)-HCT recipients and 11 autologous (auto)-HCT recipients at a median of 6.2 months (interquartile range [IQR], 1.6 to 19.3 months) post-HCT. The estimated incidence was 49.8/100,000 allo-HCT recipients and 13.7/100,000 auto-HCT recipients. The most common manifestations in our cohort were fever (n = 39; 95%), headache (n = 9; 22%), diarrhea, and impaired consciousness (n = 8 each; 20%). Four patients (10%) presented with septic shock, and 19 of 38 (50%) were severely lymphocytopenic. Thirty-seven patients (90%) had LM bacteremia. Eleven patients (27%) had neurolisteriosis, of whom 4 presented with nonspecific signs and 5 had normal brain imaging findings. Cerebrospinal fluid analysis revealed high protein and pleocytosis (mainly neutrophilic). Three-month mortality was 17% overall (n = 7), including 27% (n = 3 of 11) in patients with neurolisteriosis and 13% (n = 4 of 30) in those without neurolisteriosis. In the multivariate analysis comparing cases with 74 controls, non-first HCT (odds ratio [OR], 5.84; 95% confidence interval [CI], 1.10 to 30.82; P = .038); and lymphocytopenia <500 cells/mm3 (OR, 7.54; 95% CI, 1.50 to 37.83; P = .014) were significantly associated with listeriosis. There were no statistically significant differences in background characteristics, immunosuppression, and cotrimoxazole prophylaxis between cases and controls. HCT recipients are at increased risk for listeriosis compared to the general population. Listeriosis cause severe disease with septic shock and mortality. Neurolisteriosis can present with nonspecific signs and normal imaging. Lymphocytopenia and non-first HCT are associated with an increased risk of listeriosis, and cotrimoxazole was not protective.

The spectrum of neutralizing and non-neutralizing anti-FVIII antibodies in a nationwide cohort of 788 persons with hemophilia A.

Objectives: Anti-factor VIII (FVIII) antibodies have been reported to exhibit both neutralizing and non-neutralizing characteristics. This is the first study investigating the full spectrum of FVIII-specific antibodies, including non-neutralizing antibodies, very-low titer inhibitors, and inhibitors, in a large nationwide population of persons with hemophilia A of all severities. Methods: All persons with hemophilia A (mild (FVIII > 5-40 IU/dL)/moderate [FVIII 1-5 IU/dL)/severe (FVIII < 1 IU/dL)] with an available plasma sample who participated in the sixth Hemophilia in the Netherlands study between 2018 and 2019 were included. The presence of anti-FVIII antibodies of the immunoglobulin A, M, and G isotypes and IgG subclasses, along with antibody titer levels, were assessed using direct-binding ELISAs. FVIII specificity was assessed using a competition-based ELISA approach. The inhibitor status was determined using the Nijmegen ultra-sensitive Bethesda assay (NusBA) and the Nijmegen Bethesda assay (NBA). Results: In total, 788 persons with hemophilia A (336 (42.6%) mild, 123 (15.6%) moderate, 329 (41.8%) severe hemophilia) were included. The median age was 45 years (IQR 24-60), and the majority (50.9%) had over 150 exposure days to FVIII concentrates. Within our population, 144 (18.3%) individuals had non-neutralizing FVIII-specific antibodies, 10 (1.3%) had very low-titer inhibitors (NusBA positive; NBA negative), and 13 (1.6%) had inhibitors (both NusBA and NBA positive). IgG1 was the most abundant FVIII-specific antibody subclass, and the highest titer levels were found for IgG4. In individuals without a reported history of inhibitor development, no clear differences were observed in antibody patterns between those who were minimally or highly exposed to FVIII concentrates. IgG4 subclass antibodies were only observed in persons with a reported history of FVIII inhibitor or in those with a currently detected (very low-titer) inhibitor. Conclusion: In this cross-sectional study, we identified non-neutralizing antibodies in a relatively large proportion of persons with hemophilia A. In contrast, in our population, consisting of persons highly exposed to FVIII concentrates, (very low-titer) inhibitors were detected only in a small proportion of persons, reflecting a well-tolerized population. Hence, our findings suggest that only a small subpopulation of non-neutralizing FVIII-specific antibodies is associated with clinically relevant inhibitors.

Development of a target concentration intervention to individualize paroxysmal nocturnal hemoglobinuria treatment with pegcetacoplan.

Pegcetacoplan (Aspaveli®/Empaveli™) is a factor C3 inhibitor that is approved for the treatment of paroxysmal nocturnal hemoglobinuria. An individualized dosing strategy might be useful to improve patient-friendliness and cost-effectiveness of this very expensive drug. Therefore, the aim of this study was to develop an individualized treatment regimen for pegcetacoplan based on the pharmacokinetic-pharmacodynamic data of the manufacturer. We conducted a clinical trial simulation with the approved dosing regimen of 1080 mg twice-weekly and a target concentration intervention-based dosing regimen in patients with and without prior eculizumab use. For eculizumab-naïve patients, the target concentration intervention-based dosing regimen resulted in a comparable fraction of patients with LDH normalization (LDH < 226 U/L) and hemoglobulin normalization (> 12 g/dL) compared to the approved regimen (LDH 50.2% and 50.0% respectively and hemoglobulin 45.6% and 44.4%). A modest dose reduction of ~ 5% was possible with target concentration intervention-based dosing. An intensified dosing interval was necessary in 2.3% of the patients however an interval prolongation was possible in 28.2% of the patients. Similar results were obtained for patients prior treated with eculizumab. In this study we show the potential of an individualized dosing regimen of pegcetacoplan with can improve patient friendliness in approximately 30% of the patients and improve therapy in approximately 2% of the patients at slightly reduced costs.

Significant impact of antibiotic exposure on GI-GVHD, NRM, and GRFS following allogeneic HCT with non-myeloablative Flu-TBI conditioning.

BACKGROUND: Acute gastro-intestinal graft-versus-host disease (GI-GVHD) and non-relapse mortality (NRM) after allogeneic HCT are closely related to loss of microbial diversity and intestinal dominance by single taxa resulting from the use of antibiotics, dietary changes, and mucosal barrier injury. There is a paucity of data on the impact of use of antibiotics in HCT after Flu-TBI-based non-myeloablative (NMA) conditioning where there is absence of mucositis and limited malnutrition. METHODS: We did a retrospective single-center analysis of patients receiving Flu-TBI-based NMA HCT for a high-grade myeloid malignancy, mostly AML, and MDS, or acute lymphoblastic leukemia (ALL). We analyzed the impact of pre-engraftment antibiotic exposure, prophylactic ciprofloxacin, and or treatment with broad-spectrum cephalosporin/carbapenem, on HCT outcomes, with a focus on the incidence of acute GI-GVHD by day 180 and NRM at 1 year. RESULTS: A total of 150 patients were evaluable with a median age of 62 years. Antibiotics were used in 90 patients; 60 prophylactic use only and 30 therapeutic use with or without previous prophylaxis. Antibiotic use resulted in a significant higher incidence of GI-GVHD Stage 1-4; 29% (26/90) versus 5% (3/60) in those not receiving antibiotics (OR 8.1 (95% CI 2.3-28.3), p = 0.001). Use of antibiotics resulted in higher 1-year NRM (19% (17/90) versus 10% (6/60), HR 2.3, p = 0.06), and decreased 2-year GRFS (42% (38/90) versus 55% (33/60), HR 1.7, p = 0.04), but did not impact RFS or OS. CONCLUSIONS: Use of antibiotics was related to the occurrence of GI-GVHD, NRM, and GRFS in patients receiving truly NMA HCT. Therefore, in the absence of mucositis and low incidence of bacteremia, antibiotics can and should be used restrictively in this setting.

Pharmacokinetic-Pharmacodynamic Modelling in Hemophilia A: Relating Thrombin and Plasmin Generation to Factor VIII Activity After Administration of a VWF/FVIII Concentrate.

BACKGROUND: Hemophilia A patients are treated with factor (F) VIII prophylactically to prevent bleeding. In general, dosage and frequency are based on pharmacokinetic measurements. Ideally, an alternative dose adjustment can be based on the hemostatic potential, measured with a thrombin generation assay (TGA), like the Nijmegen hemostasis assay. OBJECTIVE: The objective of this study was to investigate the predicted performance of a previously developed pharmacokinetic-pharmacodynamic model for FVIII replacement therapy, relating FVIII dose and FVIII activity levels with thrombin and plasmin generation parameters. METHODS: Pharmacokinetic and pharmacodynamic measurements were obtained from 29 severe hemophilia A patients treated with pdVWF/FVIII concentrate (Haemate P®). The predictive performance of the previously developed pharmacokinetic-pharmacodynamic model was evaluated using nonlinear mixed-effects modeling (NONMEM). When predictions of FVIII activity or TGA parameters were inadequate [median prediction error (MPE) > 20%], a new model was developed. RESULTS: The original pharmacokinetic model underestimated clearance and was refined based on a two-compartment model. The pharmacodynamic model displays no bias in the observed normalized thrombin peak height and normalized thrombin potential (MPE of 6.83% and 7.46%). After re-estimating pharmacodynamic parameters, EC50 and Emax values were relatively comparable between the original model and this group. Prediction of normalized plasmin peak height was inaccurate (MPE 58.9%). CONCLUSION: Our predictive performance displayed adequate thrombin pharmacodynamic predictions of the original model, but a new pharmacokinetic model was required. The pharmacodynamic model is not factor specific and applicable to multiple factor concentrates. A prospective study is needed to validate the impact of the FVIII dosing pharmacodynamic model on bleeding reduction in patients.

Subjective Oral Dryness following Hematopoietic Cell Transplantation: A Report from the Orastem Study.

Xerostomia, or subjective oral dryness, is a serious complaint after hematopoietic cell transplantation (HCT). Xerostomia is rated as one of the most bothersome symptoms by HCT recipients, negatively affecting quality of life. This substudy of the Orastem study, a prospective longitudinal, international, observational, multicenter study, aimed to describe the prevalence and severity of xerostomia following HCT. Furthermore, the effect of the conditioning regimen, type of transplantation, and oral mucosal changes related to chronic graft-versus-host disease (cGVHD) in the development of xerostomia were studied. All HCT recipients rated xerostomia on a scale of 0 to 10 before the conditioning regimen, several times early post-HCT, and at 3 months post-HCT, and only allogeneic HCT recipients also rated xerostomia at 6 and 12 months post-HCT. In addition, stimulated whole mouth saliva was collected several times. Linear regression models and longitudinal mixed-effects models were created to investigate the influence of risk indicators on xerostomia. A total of 99 autologous and 163 allogeneic HCT recipients were included from 6 study sites in Sweden, Canada, the Netherlands, and the United States. The prevalence of xerostomia was 40% before the conditioning regimen, 87% early post-HCT, and 64% at 3 months post-HCT. Complaints after autologous HCT were transient in nature, while the severity of xerostomia in allogeneic HCT recipients remained elevated at 12 months post-HCT. Compared to autologous HCT recipients, allogeneic HCT recipients experienced 1.0 point more xerostomia (95% confidence interval [CI], .1 to 2.0) early post-HCT and 1.7 points more (95% CI, .4 to 3.0) at 3 months post-HCT. Allogeneic HCT recipients receiving a high-intensity conditioning regimen experienced more xerostomia compared to those receiving a nonmyeloablative or reduced-intensity conditioning regimen. The difference was 2.0 points (95% CI, 1.1 to 2.9) early post-HCT, 1.8 points (95% CI, .3 to 3.3) after 3 months, and 1.7 points (95% CI, .0 to 3.3) after 12 months. Total body irradiation as part of the conditioning regimen and oral mucosal changes related to cGVHD did not significantly influence the severity of xerostomia. Conditioning regimen intensity was a significant risk indicator in the development of xerostomia, whereas total body irradiation was not. Allogeneic HCT recipients experienced more xerostomia than autologous HCT recipients, a difference that cannot be explained by a reduction in stimulated salivary flow rate or the development of oral mucosal changes related to cGVHD.

Upper and/or Lower Respiratory Tract Infection Caused by Human Metapneumovirus After Allogeneic Hematopoietic Stem Cell Transplantation.

BACKGROUND: Human metapneumovirus (hMPV) epidemiology, clinical characteristics and risk factors for poor outcome after allogeneic stem cell transplantation (allo-HCT) remain a poorly investigated area. METHODS: This retrospective multicenter cohort study examined the epidemiology, clinical characteristics, and risk factors for poor outcomes associated with human metapneumovirus (hMPV) infections in recipients of allo-HCT. RESULTS: We included 428 allo-HCT recipients who developed 438 hMPV infection episodes between January 2012 and January 2019. Most recipients were adults (93%). hMPV infections were diagnosed at a median of 373 days after allo-HCT. The infections were categorized as upper respiratory tract disease (URTD) or lower respiratory tract disease (LRTD), with 60% and 40% of cases, respectively. Patients with hMPV LRTD experienced the infection earlier in the transplant course and had higher rates of lymphopenia, neutropenia, corticosteroid use, and ribavirin therapy. Multivariate analysis identified lymphopenia and corticosteroid use (>30 mg/d) as independent risk factors for LRTD occurrence. The overall mortality at day 30 after hMPV detection was 2% for URTD, 12% for possible LRTD, and 21% for proven LRTD. Lymphopenia was the only independent risk factor associated with day 30 mortality in LRTD cases. CONCLUSIONS: These findings highlight the significance of lymphopenia and corticosteroid use in the development and severity of hMPV infections after allo-HCT, with lymphopenia being a predictor of higher mortality in LRTD cases.

Reproductive outcomes and reproductive health care utilization among male survivors of childhood cancer: A DCCSS-LATER study.

BACKGROUND: Treatment-related gonadal dysfunction leading to fertility problems is a frequently encountered late effect in childhood cancer survivors (CCSs). This study evaluated reproductive outcomes and reproductive health care utilization among male CCSs compared with male siblings. METHODS: A nationwide cohort study was conducted as part of the Dutch Childhood Cancer Survivor LATER study part 1, a questionnaire and linkage study. A questionnaire addressing reproductive outcomes and reproductive health care was completed by 1317 male CCSs and 407 male siblings. A total of 491 CCSs and 185 siblings had a previous or current desire for children and were included in this study. RESULTS: Fewer CCSs had biological children compared with siblings (65% vs. 88%; p < .001). The type of conception by men who fathered a child was comparable between CCSs and siblings (spontaneous conception of 90% of both groups; p = .86). The percentage of men who had consulted a reproductive specialist because of not siring a pregnancy was higher in CCSs compared with siblings (34% vs. 12%; p < .001). Following consultation, fewer CCSs underwent assisted reproductive techniques (ART) compared with siblings (41% vs. 77%; p = .001). After ART, fewer CCSs fathered a child compared with siblings (49% vs. 94%; p = .001). CONCLUSIONS: More male survivors consult a reproductive specialist, but fewer survivors undergo ART and father a child after ART compared with siblings. This insight is important for understanding potential problems faced by survivors regarding family planning and emphasizes the importance of collaboration between oncologists and reproductive specialists.

Patients with moderate hemophilia A and B with a severe bleeding phenotype have an increased burden of disease.

BACKGROUND: Patients with moderate hemophilia express varying bleeding phenotypes. OBJECTIVES: To assess the burden of disease in patients with moderate hemophilia and a mild or severe phenotype incorporating the thrombin generation profile. METHODS: This sub-study of the 6th Hemophilia in the Netherlands study, analyzed data of adults with moderate hemophilia A or B. Patient characteristics and information on bleeding tendency, joint status, and quality of life were obtained from electronic patient files and self-reported questionnaires. A severe bleeding phenotype was defined as an annual bleeding rate ≥5, an annual joint bleeding rate ≥3, and/or the use of secondary/tertiary prophylaxis, and a mild phenotype vice versa. TG was measured with the Nijmegen Hemostasis Assay. RESULTS: This study included 116 patients: 21% had a severe phenotype of whom 46% used prophylaxis. Patients with a severe phenotype treated on demand reported a higher median annual bleeding rate (7), annual joint bleeding rate (3), and more frequently an impaired joint (77%) than patients with a severe phenotype on prophylaxis (2; 0; 70%) or patients with a mild phenotype (0; 0; 47%). Furthermore, patients with a severe phenotype treated on demand experienced a more decreased quality of life. Despite similar factor activity levels, patients with a severe phenotype had a lower thrombin peak height and thrombin potential (0.7%; 0.06%) than patients with a mild phenotype (21.3%; 46.8%). CONCLUSION: Patients with moderate hemophilia and a severe phenotype treated on demand displayed a high burden of disease as well as a low thrombin generation profile advocating them toward more intensive prophylactic treatment.

Guidelines for the management of Toxoplasma gondii infection and disease in patients with haematological malignancies and after haematopoietic stem-cell transplantation: guidelines from the 9th European Conference on Infections in Leukaemia, 2022.

Patients with haematological malignancies might develop life-threatening toxoplasmosis, especially after allogeneic haematopoietic stem-cell transplantation (HSCT). Reactivation of latent cysts is the primary mechanism of toxoplasmosis following HSCT; hence, patients at high risk are those who were seropositive before transplantation. The lack of trimethoprim-sulfamethoxazole prophylaxis and various immune status parameters of the patient are other associated risk factors. The mortality of toxoplasma disease-eg, with organ involvement-can be particularly high in this setting. We have developed guidelines for managing toxoplasmosis in haematology patients, through a literature review and consultation with experts. In allogeneic HSCT recipients seropositive for Toxoplasma gondii before transplant, because T gondii infection mostly precedes toxoplasma disease, we propose weekly blood screening by use of quantitative PCR (qPCR) to identify infection early as a pre-emptive strategy. As trimethoprim-sulfamethoxazole prophylaxis might fail, prophylaxis and qPCR screening should be combined. However, PCR in blood can be negative even in toxoplasma disease. The duration of prophylaxis should be a least 6 months and extended during treatment-induced immunosuppression or severe CD4 lymphopenia. If a positive qPCR test occurs, treatment with trimethoprim-sulfamethoxazole, pyrimethamine-sulfadiazine, or pyrimethamine-clindamycin should be started, and a new sample taken. If the second qPCR test is negative, clinical judgement is recommended to either continue or stop therapy and restart prophylaxis. Therapy must be continued until a minimum of two negative PCRs for infection, or for at least 6 weeks for disease. The pre-emptive approach is not indicated in seronegative HSCT recipients, after autologous transplantation, or in non-transplant haematology patients, but PCR should be performed with a high level of clinical suspicion.

Engineering of CD34+ progenitor-derived natural killer cells with higher-affinity CD16a for enhanced antibody-dependent cellular cytotoxicity.

BACKGROUND AIMS: Natural killer (NK) cell transfer is a promising cellular immunotherapy for cancer. Previously, we developed a robust method to generate large NK cell numbers from CD34+ hematopoietic stem and progenitor cells (HSPCs), which exhibit strong anti-tumor activity. However, since these cells express low levels of the Fc receptor CD16a in vitro, antibody-dependent cellular cytotoxicity (ADCC) by these cells is limited. To broaden clinical applicability of our HSPC-NK cells toward less NK-sensitive malignancies, we aimed to improve ADCC through CD16a transduction. METHODS: Using wildtype and S197P mutant greater-affinity (both with V158) CD16a retroviral transgenes (i.e., a cleavable and noncleavable CD16a upon stimulation), we generated CD16a HSPC-transduced NK cells, with CD34+ cells isolated from umbilical cord blood (UCB) or peripheral blood after G-CSF stem cell mobilization (MPB). CD16a expressing NK cells were enriched using flow cytometry-based cell sorting. Subsequently, phenotypic analyses and functional assays were performed to investigate natural cytotoxicity and ADCC activity. RESULTS: Mean transduction efficiency was 34% for UCB-derived HSPCs and 20% for MPB-derived HSPCs, which was enriched by flow cytometry-based cell sorting to >90% for both conditions. Expression of the transgene remained stable during the entire NK expansion cell generation process. Proliferation and differentiation of HSPCs were not hampered by the transduction process, resulting in effectively differentiated CD56+ NK cells after 5 weeks. Activation of the HSPC-derived NK cells resulted in significant shedding of wildtype CD16a transcribed from the endogenous gene, but not of the noncleavable mutant CD16a protein expressed from the transduced construct. The mean increase of CD107+IFNγ+ expressing NK cells after inducing ADCC was tenfold in enriched noncleavable CD16a HSPC-NK cells. Killing capacity of CD16a-transduced NK cells was significantly improved after addition of a tumor-targeting antibody in tumor cell lines and primary B-cell leukemia and lymphoma cells compared to unmodified HSPC-NK cells. CONCLUSIONS: Together, these data demonstrate that the applicability of adoptive NK cell immunotherapy may be broadened to less NK-sensitive malignancies by upregulation of CD16a expression in combination with the use of tumor-targeting monoclonal antibodies.

Transporter-Mediated Cellular Distribution of Tyrosine Kinase Inhibitors as a Potential Resistance Mechanism in Chronic Myeloid Leukemia.

Chronic myeloid leukemia (CML) is a hematologic neoplasm characterized by the expression of the BCR::ABL1 oncoprotein, a constitutively active tyrosine kinase, resulting in uncontrolled growth and proliferation of cells in the myeloid lineage. Targeted therapy using tyrosine kinase inhibitors (TKIs) such as imatinib, nilotinib, dasatinib, bosutinib, ponatinib and asciminib has drastically improved the life expectancy of CML patients. However, treatment resistance occurs in 10-20% of CML patients, which is a multifactorial problem that is only partially clarified by the presence of TKI inactivating BCR::ABL1 mutations. It may also be a consequence of a reduction in cytosolic TKI concentrations in the target cells due to transporter-mediated cellular distribution. This review focuses on drug-transporting proteins in stem cells and progenitor cells involved in the distribution of TKIs approved for the treatment of CML. Special attention will be given to ATP-binding cassette transporters expressed in lysosomes, which may facilitate the extracytosolic sequestration of these compounds.

10-day decitabine versus 3 + 7 chemotherapy followed by allografting in older patients with acute myeloid leukaemia: an open-label, randomised, controlled, phase 3 trial.

BACKGROUND: Many older patients with acute myeloid leukaemia die or cannot undergo allogeneic haematopoietic stem-cell transplantation (HSCT) due to toxicity caused by intensive chemotherapy. We hypothesised that replacing intensive chemotherapy with decitabine monotherapy could improve outcomes. METHODS: This open-label, randomised, controlled, phase 3 trial was conducted at 54 hospitals in nine European countries. Patients aged 60 years and older who were newly diagnosed with acute myeloid leukaemia and had not yet been treated were enrolled if they had an Eastern Cooperative Oncology Group performance status of 2 or less and were eligible for intensive chemotherapy. Patients were randomly assigned (1:1) to receive decitabine or standard chemotherapy (known as 3 + 7). For the decitabine group, decitabine (20 mg/m2) was administered for the first 10 days in the first 28-day cycle, followed by 28-day cycles consisting of 5 days or 10 days of decitabine. For the 3 + 7 group, daunorubicin (60 mg/m2) was administered over the first 3 days and cytarabine (200 mg/m2) over the first 7 days, followed by 1-3 additional chemotherapy cycles. Allogeneic HSCT was strongly encouraged. Overall survival in the intention-to-treat population was the primary endpoint. Safety was assessed in all patients who received the allocated treatment. This trial is registered at ClinicalTrials.gov, NCT02172872, and is closed to new participants. FINDINGS: Between Dec 1, 2014, and Aug 20, 2019, 606 patients were randomly assigned to the decitabine (n=303) or 3 + 7 (n=303) group. Following an interim analysis which showed futility, the IDMC recommended on May 22, 2019, that the study continued as planned considering the risks and benefits for the patients participating in the study. The cutoff date for the final analysis presented here was June 30, 2021. At a median follow-up of 4·0 years (IQR 2·9-4·8), 4-year overall survival was 26% (95% CI 21-32) in the decitabine group versus 30% (24-35) in the 3 + 7 group (hazard ratio for death 1·04 [95% CI 0·86-1·26]; p=0·68). Rates of on-protocol allogeneic HSCT were similar between groups (122 [40%] of 303 patients for decitabine and 118 [39%] of 303 patients for 3+7). Rates of grade 3-5 adverse events were 254 (84%) of 302 patients in the decitabine group and 279 (94%) of 298 patients in the 3 + 7 group. The rates of grade 3-5 infections (41% [125 of 302] vs 53% [158 of 298]), oral mucositis (2% [seven of 302] vs 10% [31 of 298]) and diarrhoea (1% [three of 302] vs 8% [24 of 298]) were lower in the decitabine group than in the 3 + 7 group. Treatment-related deaths were reported for 12% (35 of 302) of patients in the decitabine group and 14% (41 of 298) in the 3 + 7 group. INTERPRETATION: 10-day decitabine did not improve overall survival but showed a better safety profile compared with 3 + 7 chemotherapy in older patients with acute myeloid leukaemia eligible for intensive chemotherapy. Decitabine could be considered a better-tolerated and sufficiently efficacious alternative to 3 + 7 induction in fit older patients with acute myeloid leukaemia without favourable genetics. FUNDING: Janssen Pharmaceuticals.

Meta-pharmacokinetic analysis of posaconazole following dosing of oral suspension, delayed-release tablet, and intravenous infusion in patients vs. healthy volunteers: Impact of clinical characteristics and race.

OBJECTIVES: To investigate the potential impact of clinical characteristics and the Chinese race on posaconazole pharmacokinetics in patients using an integrated population pharmacokinetic model for posaconazole oral suspension (SUS), delayed-release tablet (DR-tablet), and intravenous (IV) infusion that was developed in healthy volunteers (HV). METHODS: 1046 concentrations from 105 prospectively studied Caucasian patients receiving either of the three posaconazole formulations were pooled with 3898 concentrations from 182 HV. Clinical characteristics were tested for significance. The impact of Chinese race was assessed using 292 opportunistic samples from 80 Chinese patients receiving SUS. RESULTS: Bioavailability of SUS (Fsus) in patients decreased from 38.2% to 24.6% when the dose was increased from 100 mg to 600 mg. Bioavailability of DR-tablet (Ftab) was 59% regardless of dose. Mucositis, diarrhoea, administration through a nasogastric tube, and concomitant use of proton pump inhibitors or metoclopramide reduced Fsus by 61%, 36%, 44%, 48%, and 29%, respectively, putting patients with these characteristics at increased risk of inadequate exposure. Clearance decreased from 7.0 to 5.1 L/h once albumin levels were <30 g/L. Patients showed an 84.4% larger peripheral volume of distribution (Vp) and 67.5% lower intercompartmental clearance (Q) compared with HV. No racial difference could be identified. CONCLUSIONS: Pharmacokinetics of posaconazole in patients differ considerably to those in HV, with altered Fsus that is also impacted by clinical covariates, an Ftab similar to fasted conditions in HV, and altered parameters for clearance, Vp, and Q. There was no evidence to indicate that Chinese patients require a different dose to Caucasian patients.

The Nijmegen ultra-sensitive Bethesda Assay detects very low-titer factor VIII inhibitors in patients with congenital and acquired hemophilia A.

BACKGROUND: An inhibitor can develop in congenital hemophilia A (HA) patients against exogenous infused factor (F)VIII, whereas in acquired HA (AHA) inhibitors initially develop against endogenous FVIII. Inhibitors can be detected with the Nijmegen Bethesda Assay (NBA), which has an international cut-off level of 0.60 Nijmegen Bethesda Units/mL (NBU/mL). Thereby, very low-titer inhibitors may remain undetected. AIM: To describe the design and validation of the Nijmegen ultra-sensitive Bethesda Assay (NusBA) for the detection of very low-titer inhibitors. METHODS: The NusBA is a modification of the NBA in which the ratio of patient plasma to normal pooled plasma is changed from 1:1 to 9:1. Analytical validation was performed according to the CLSI EP10 guideline in order to determine trueness and reproducibility. Clinical validation was performed in two cohorts of congenital HA patients (82 adults) with pharmacokinetic data and four AHA patients. The limit of quantitation (LOQ) was determined by measuring plasma samples spiked with inhibitor levels in the low range (0.05-0.80 NBU/mL). RESULTS: The LOQ for the NusBA was 0.10 NusBU/mL, with a coefficient of variation of 24.2 %. Seven (8.5 %) congenital HA patients had a positive NusBA result, of which only one was detected with the NBA. There was no correlation between NusBA and FVIII half-life. In three of the AHA patients the NusBA remained positive, when the NBA became negative. DISCUSSION: The NusBA is able to detect very low-titer FVIII inhibitors of ≥0.10 NBU/mL. Thereby, it may have added value in early inhibitor detection and therapy adjustments in patients with congenital HA and AHA.

The Value of IgM Memory B-Cells in the Assessment of Splenic Function in Childhood Cancer Survivors at Risk for Splenic Dysfunction: A DCCSS-LATER Study.

Background: Childhood cancer survivors (CCS) who received radiotherapy involving the spleen or total body irradiation (TBI) might be at risk for splenic dysfunction. A comprehensive screening test for examining splenic dysfunction is lacking. Objective: We investigated whether IgM memory B-cells could be used to assess splenic dysfunction in CCS who received a splenectomy, radiotherapy involving the spleen, or TBI. Methods: All CCS were enrolled from the DCCSS-LATER cohort. We analyzed differences in IgM memory B-cells and Howell-Jolly bodies (HJB) in CCS who had a splenectomy (n = 9), received radiotherapy involving the spleen (n = 36), or TBI (n = 15). IgM memory B-cells < 9 cells/µL was defined as abnormal. Results: We observed a higher median number of IgM memory B-cells in CCS who received radiotherapy involving the spleen (31 cells/µL, p=0.06) or TBI (55 cells/µL, p = 0.03) compared to CCS who received splenectomy (20 cells/µL). However, only two CCS had IgM memory B-cells below the lower limit of normal. No difference in IgM memory B-cells was observed between CCS with HJB present and absent (35 cells/µL vs. 44 cells/µL). Conclusion: Although the number of IgM memory B-cells differed between splenectomized CCS and CCS who received radiotherapy involving the spleen or TBI, only two CCS showed abnormal values. Therefore, this assessment cannot be used to screen for splenic dysfunction.