Acute kidney injury in Staphylococcus aureus bacteremia: a recurrent events analysis.

OBJECTIVES: To estimate risk factors for AKI and the effect of AKI on mortality in Staphylococcus aureus bacteremia, while taking into account recurrent AKI episodes, competing risks, time-varying variables and time-varying effects. METHODS: We performed an unplanned analysis using data from a multicenter cohort study of patients with SAB. Primary outcome was cumulative incidence of AKI, according to KDIGO definitions. RESULTS: We included 453 patients in this study of whom 194 (43%) patients experienced one or more AKI episodes. Age (HR 1.013, 95% CI 1.001 - 1.024), Charlson comorbidity index (HR 1.07, 95% CI 1.01 - 1.14), prior chronic kidney disease (HR 1.76, 95% CI 1.28 - 2.42), septic shock (HR 3.28, 95% CI 2.31 - 4.66), persistent bacteremia (HR 1.53, 95% CI 1.08 - 2.17) and vancomycin therapy (HR 1.80, 95% CI 1.05 - 3.09) were independently associated with AKI, but flucloxacillin, cefazolin, rifampicin and aminoglycoside therapy were not. After adjustment for confounders and immortal time bias, AKI was associated with an increased risk of 90-day mortality (HR 4.26, 95% CI 2.91 - 6.23). CONCLUSIONS: Incidence of AKI in SAB is high and a substantial proportion of patients develops recurrent episodes of AKI after recovery. AKI is specifically linked to the use of vancomycin and not to anti-staphylococcal penicillins. Clinical outcome of patients with SAB complicated by AKI is worse than previously estimated.

Good manufacturing practice production of CD34+ progenitor-derived NK cells for adoptive immunotherapy in acute myeloid leukemia.

Allogeneic natural killer (NK) cell-based immunotherapy is a promising, well-tolerated adjuvant therapeutic approach for acute myeloid leukemia (AML). For reproducible NK cell immunotherapy, a homogenous, pure and scalable NK cell product is preferred. Therefore, we developed a good manufacturing practice (GMP)-compliant, cytokine-based ex vivo manufacturing process for generating NK cells from CD34+ hematopoietic stem and progenitor cells (HSPC). This manufacturing process combines amongst others IL15 and IL12 and the aryl hydrocarbon receptor antagonist StemRegenin-1 (SR1) to generate a consistent and active NK cell product that fits the requirements for NK cell immunotherapy well. The cell culture protocol was first optimized to generate NK cells with required expansion and differentiation capacity in GMP-compliant closed system cell culture bags. In addition, phenotype, antitumor potency, proliferative and metabolic capacity were evaluated to characterize the HSPC-NK product. Subsequently, seven batches were manufactured for qualification of the process. All seven runs demonstrated consistent results for proliferation, differentiation and antitumor potency, and preliminary specifications for the investigational medicinal product for early clinical phase trials were set. This GMP-compliant manufacturing process for HSPC-NK cells (named RNK001 cells) is used to produce NK cell batches applied in the clinical trial 'Infusion of ex vivo-generated allogeneic natural killer cells in combination with subcutaneous IL2 in patients with acute myeloid leukemia' approved by the Dutch Ethics Committee (EudraCT 2019-001929-27).

Comparative effectiveness of ß-lactams for empirical treatment of methicillin-susceptible Staphylococcus aureus bacteraemia: a prospective cohort study.

OBJECTIVES: Standard once-daily dosing of ceftriaxone may not lead to adequate antibiotic exposure in all cases of Staphylococcus aureus bacteraemia (SAB). Therefore, we compared clinical effectiveness of empirical antibiotic treatment with flucloxacillin, cefuroxime and ceftriaxone in adult patients with MSSA bacteraemia. METHODS: We analysed data from the Improved Diagnostic Strategies in Staphylococcus aureus bacteraemia (IDISA) study, a multicentre prospective cohort study of adult patients with MSSA bacteraemia. Duration of bacteraemia and 30 day SAB-related mortality were compared between the three groups using multivariable mixed-effects Cox regression analyses. RESULTS: In total, 268 patients with MSSA bacteraemia were included in the analyses. Median duration of empirical antibiotic therapy was 3 (IQR 2-3) days in the total study population. Median duration of bacteraemia was 1.0 (IQR 1.0-3.0) day in the flucloxacillin, cefuroxime and ceftriaxone groups. In multivariable analyses, neither ceftriaxone nor cefuroxime was associated with increased duration of bacteraemia compared with flucloxacillin (HR 1.08, 95% CI 0.73-1.60 and HR 1.22, 95% CI 0.88-1.71). In multivariable analysis, neither cefuroxime nor ceftriaxone was associated with higher 30 day SAB-related mortality compared with flucloxacillin [subdistribution HR (sHR) 1.37, 95% CI 0.42-4.52 and sHR 1.93, 95% CI 0.67-5.60]. CONCLUSIONS: In this study, we could not demonstrate a difference in duration of bacteraemia and 30 day SAB-related mortality between patients with SAB empirically treated with flucloxacillin, cefuroxime or ceftriaxone. Since sample size was limited, it is possible the study was underpowered to find a clinically relevant effect.

Assessing Biodegradability of Chemical Compounds from Microbial Community Growth Using Flow Cytometry.

Compound biodegradability tests with natural microbial communities form an important keystone in the ecological assessment of chemicals. However, biodegradability tests are frequently limited by a singular focus either on the chemical and potential transformation products or on the individual microbial species degrading the compound. Here, we investigated a methodology to simultaneously analyze community compositional changes and biomass growth on dosed test compound from flow cytometry (FCM) data coupled to machine-learned cell type recognition. We quantified the growth of freshwater microbial communities on a range of carbon dosages of three readily biodegradable reference compounds, phenol, 1-octanol, and benzoate, in comparison to three fragrances, methyl jasmonate, myrcene, and musk xylene (as a nonbiodegradable control). Compound mass balances with between 0.1 to 10 mg C · liter-1 phenol or 1-octanol, inferred from cell numbers, parent compound analysis, and CO2 evolution, as well as use of 14C-labeled compounds, showed between 6 and 25% mg C · mg C-1 substrate incorporation into biomass within 2 to 4 days and 25 to 45% released as CO2 In contrast, similar dosage of methyl jasmonate and myrcene supported slower (4 to 10 days) and less (2.6 to 6.6% mg C · mg C-1 with 4.9 to 22% CO2) community growth. Community compositions inferred from machine-learned cell type recognition and 16S rRNA amplicon sequencing showed substrate- and concentration-dependent changes, with visible enrichment of microbial subgroups already at 0.1 mg C · liter-1 phenol and 1-octanol. In general, community compositions were similar at the start and after the stationary phase of the microbial growth, except at the highest used substrate concentrations of 100 to 1,000 mg C · liter-1 Flow cytometry cell counting coupled to deconvolution of communities into subgroups is thus suitable to infer biodegradability of organic chemicals, permitting biomass balances and near-real-time assessment of relevant subgroup changes.IMPORTANCE The manifold effects of potentially toxic compounds on microbial communities are often difficult to discern. Some compounds may be transformed or completely degraded by few or multiple strains in the community, whereas others may present inhibitory effects. In this study, we benchmark a new method based on machine-learned microbial cell recognition to rapidly follow dynamic changes in aquatic communities. We further determine productive biodegradation upon dosing of a number of well-known readily biodegradable tester compounds at a variety of concentrations. Microbial community growth was quantified using flow cytometry, and the multiple cell parameters measured were used in parallel to deconvolute the community on the basis of similarity to previously standardized cell types. Biodegradation was further confirmed by chemical analysis, showing how distinct changes in specific populations correlate to degradation. The method holds great promise for near-real-time community composition changes and deduction of compound biodegradation in natural microbial communities.

IL-15 superagonist N-803 improves IFNγ production and killing of leukemia and ovarian cancer cells by CD34+ progenitor-derived NK cells.

Allogeneic natural killer (NK) cell transfer is a potential immunotherapy to eliminate and control cancer. A promising source are CD34 + hematopoietic progenitor cells (HPCs), since large numbers of cytotoxic NK cells can be generated. Effective boosting of NK cell function can be achieved by interleukin (IL)-15. However, its in vivo half-life is short and potent trans-presentation by IL-15 receptor α (IL-15Rα) is absent. Therefore, ImmunityBio developed IL-15 superagonist N-803, which combines IL-15 with an activating mutation, an IL-15Rα sushi domain for trans-presentation, and IgG1-Fc for increased half-life. Here, we investigated whether and how N-803 improves HPC-NK cell functionality in leukemia and ovarian cancer (OC) models in vitro and in vivo in OC-bearing immunodeficient mice. We used flow cytometry-based assays, enzyme-linked immunosorbent assay, microscopy-based serial killing assays, and bioluminescence imaging, for in vitro and in vivo experiments. N-803 increased HPC-NK cell proliferation and interferon (IFN)γ production. On leukemia cells, co-culture with HPC-NK cells and N-803 increased ICAM-1 expression. Furthermore, N-803 improved HPC-NK cell-mediated (serial) leukemia killing. Treating OC spheroids with HPC-NK cells and N-803 increased IFNγ-induced CXCL10 secretion, and target killing after prolonged exposure. In immunodeficient mice bearing human OC, N-803 supported HPC-NK cell persistence in combination with total human immunoglobulins to prevent Fc-mediated HPC-NK cell depletion. Moreover, this combination treatment decreased tumor growth. In conclusion,  N-803 is a promising IL-15-based compound that boosts HPC-NK cell expansion and functionality in vitro and in vivo. Adding N-803 to HPC-NK cell therapy could improve cancer immunotherapy.

Implementation of the 2015 European Society of Cardiology guidelines for the management of infective endocarditis in the Netherlands.

Because the occurrence of infective endocarditis (IE) continues to be associated with high mortality, a working group was created by the Dutch Society of Cardiology to examine how the most recent European Society of Cardiology (ESC) guidelines for IE management could be implemented most effectively in the Netherlands. In order to investigate current Dutch IE practices, the working group conducted a country-wide survey. Based on the results obtained, it was concluded that most ESC recommendations could be endorsed, albeit with some adjustments. For instance, the suggested pre-operative screening and treatment of nasal carriers of Staphylococcus aureus as formulated in the ESC guideline was found to be dissimilar to current Dutch practice, and was therefore made less restrictive. The recently adapted ESC diagnostic criteria for IE were endorsed, while the practical employment of the relevant diagnostic techniques was simplified in an adapted flowchart. In addition, the presence of a multidisciplinary, so-called 'endocarditis team' in tertiary centres was proposed as a quality indicator. An adapted flowchart specifically tailored to Dutch practice for microbiological diagnostic purposes was constructed. Lastly, the working group recommended the Stichting Werkgroep Antibioticabeleid (SWAB; Dutch Working Party on Antibiotic Policy) guidelines for IE treatment instead of the antibiotic regimens proposed by the ESC.

[Antibiotic prophylaxis and endocarditis]. / AB-profylaxe en endocarditis.

The use of antibiotics before an invasive dental procedure to prevent endocarditis as a consequence of the procedure is based on experimental research on animals. The efficacy of this measure has, however, not yet been demonstrated in humans. Starting in 2007, therefore, fewer heart diseases have been indicated for endocarditis prophylaxis.

Pitfalls in cytokine measurements - Plasma TGF-ß1 in chronic fatigue syndrome.

BACKGROUND: Serum TGF-ß1 concentrations are reported to be elevated in chronic fatigue syndrome (CFS). However, measurement of circulating cytokines is a complex procedure and control of pre-analytical procedures is essential. The objective of the current study was to measure circulating TGF-ß1 concentrations in CFS patients compared to healthy controls, taking into account differences in pre-analytical procedures. METHODS: Two cohorts of female CFS patients were included. In both studies patients were asked to bring a healthy, age-matched control. At baseline, TGF-ß1 levels were measured in plasma and additionally P-selectin, a marker of platelet activity, was determined in a subgroup of participants. RESULTS: 50 patients and 48 controls were included in cohort I, and 90 patients and 29 controls in cohort II. Within the cohorts there were no differences in TGF-ß1 concentrations. However, between the cohorts there was a large discrepancy, which appeared to be caused by differences in g-force of the centrifuges used. The lower g-force used in cohort II (1361 g) caused more platelet activation, reflected by higher p-selectin concentrations, compared to cohort I (p < 0.0001), which was confirmed in a second independent experiment. There was a correlation between TGF-ß1 and p-selectin concentrations (r 0.79, p < 0.0001). CONCLUSION: These results demonstrate that control of pre-analytical procedures is an essential aspect when measuring circulating cytokines. No evidence for enhanced TGF-ß1 in patients with CFS was found.

[Report of the Dutch National Health Council on chronic fatigue syndrome]. / GR-rapport over chronische-vermoeidheidssyndroom.

In our opinion, the recent report of the Dutch National Health Council on myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) lacks balance: it is very critical on the quality of evidence regarding behavioural interventions, but lacks a critical attitude regarding the presumed somatic components of the disorder. Without solid evidence, the report coins ME/CFS as a severe multisystem disease, and it embraces the diagnostic criteria of the American Institute of Medicine. We underscore the remarks in the report that physicians should not be reluctant to make diagnosis in patients with the disorder, and that these patients should be approached with empathy and respect. Regarding a future research programme, there is need for a well-designed research agenda.

[Bacteriophages in the battle against multidrug resistant bacteria]. / Bacteriofagen in de strijd tegen multiresistente bacteriën.

Bacteriophages are viruses that infect bacteria. They are highly specific for a bacterial species. The so-called 'lytic phages' can lyse bacteria when they infect them; these phages can be used to treat bacterial infections. Despite a century of experience with phage therapy, the evidence for clinical efficacy is limited. Side effects are generally considered to be mild. The selection, preparation and administration of phages for therapy is laborious, and investigations into the clinical benefits are not easy. More research is needed, also in the face of the increasing antimicrobial resistance.

Pitfall of modern genetics: recurrent erysipelas masquerading as autoinflammatory disease.

A patient presented with recurrent episodes of fever and skin rash for eight years. DNA analysis of the NLRP3 gene revealed a mutation associated with autoinflammatory disease. After an initial positive response to the biological anakinra, the patient deteriorated. Reassessment revealed recurrent erysipelas. In conclusion, sometimes erysipelas-like skin rash is real erysipelas, and DNA results are not always the final answer.

Risk of infections in patients with gout: a population-based cohort study.

To investigate the risk of various types of infections (pneumonia and urinary tract infection (UTI)), and infection-related mortality in patients with gout compared with population-based controls. A retrospective cohort study was conducted using data from the UK Clinical Practice Research Datalink (CPRD). All patients with a first diagnosis of gout and aged >40 years between January 1987-July 2014, were included and matched with up to two controls. Time-varying Cox proportional hazards models were used to estimate the risk of infections and mortality. 131,565 patients and 252,763 controls (mean age: 64 years, 74% males, mean follow-up of 6.7 years) were included in the full cohort. After full statistical adjustment, the risk of pneumonia was increased (adj. HR 1.27, 95% CI 1.18 to 1.36), while the risk of UTI (adj. HR 0.99, 95% CI 0.97 to 1.01) was similar in patients compared to controls. No differences between patients and controls were observed for infection-related mortality due to pneumonia (adj. HR 1.03, 95% CI 0.93 to 1.14) or UTI (adj. HR 1.16, 95% CI 0.98 to 1.37). In conclusion, patients with gout did not have decreased risks of pneumonia, UTI or infection-related mortality compared to population-based controls.

Intact interferon-γ response against Coxiella burnetii by peripheral blood mononuclear cells in chronic Q fever.

OBJECTIVES: Q fever is caused by Coxiella burnetii, an intracellular bacterium that infects phagocytes. The aim of the present study was to investigate whether the C. burnetii-induced IFN-γ response is defective in chronic Q fever patients. METHODS: IFN-γ was measured in supernatants of C. burnetii-stimulated peripheral blood mononuclear cells (PBMCs) of 17 chronic Q fever patients and 17 healthy individuals. To assess IFN-γ responses, expression profiles of IFN-γ-induced genes in C. burnetii-stimulated PBMCs were studied in six patients and four healthy individuals. Neopterin was measured in PBMC supernatants (of eight patients and four healthy individuals) and in sera (of 21 patients and 11 healthy individuals). In a genetic association study, polymorphisms in genes involved in the Th1-cytokine response were analysed in a cohort of 139 chronic Q fever patients and a cohort of 220 control individuals with previous exposition to C. burnetii. RESULTS: IFN-γ production by C. burnetii-stimulated PBMCs from chronic Q fever patients was significantly higher than in healthy controls. Many IFN-γ response genes were strongly upregulated in PBMCs of patients. Neopterin levels were significantly higher in PBMC supernatants and sera of patients. The IL12B polymorphisms rs3212227 and rs2853694 were associated with chronic Q fever. CONCLUSIONS: IFN-γ production, as well as the response to IFN-γ, is intact in chronic Q fever patients, and even higher than in healthy individuals. Polymorphisms in the IL-12p40 gene are associated with chronic Q fever. Thus, a deficiency in IFN-γ responses does not explain the failure to clear the infection. The genetic data suggest, however, that the IL-12/IFN-γ pathway does play a role.

Postural orthostatic tachycardia is not a useful diagnostic marker for chronic fatigue syndrome.

BACKGROUND: Postural orthostatic tachycardia syndrome (POTS) is considered a diagnostic marker for chronic fatigue syndrome (CFS). OBJECTIVES: The aims of this study were to (i) compare POTS prevalence in a CFS cohort with fatigued patients not meeting CFS criteria, and (ii) assess activity, impairment and response to cognitive behavioural therapy (CBT) in CFS patients with POTS (POTS-CFS) and without POTS (non-POTS-CFS). METHODS: Prospective cohort study at the Radboud University Medical Centre in the Netherlands. Between June 2013 and December 2014, 863 consecutive patients with persistent fatigue were screened. Patients underwent an active standing test, filled out questionnaires and wore an activity-sensing device for a period of 12 days. RESULTS: A total of 419 patients with CFS and 341 non-CFS fatigued patients were included in the study. POTS prevalence in adult patients with CFS was 5.7% vs. 6.9% in non-CFS adults (P = 0.54). In adolescents, prevalence rates were 18.2% and 17.4%, respectively (P = 0.93). Adult patients with POTS-CFS were younger (30 ± 12 vs. 40 ± 13 years, P = 0.001) and had a higher supine heart rate (71 ± 11 vs. 65 ± 9 beats per min, P = 0.009) compared with non-POTS-CFS patients. Severity and activity patterns did not differ between groups. In patients with CFS, criteria for Systemic Exertion Intolerance Disease (SEID) were met in 76% of adults and 67% of adolescents. In these patients with CFS fulfilling the SEID criteria, the prevalence of POTS was not different from that in the overall CFS population. POTS-CFS adolescents had less clinically significant improvement after CBT than non-POTS-CFS adolescents (58% vs. 88%, P = 0.017). CONCLUSION: In adults with CFS, the prevalence of POTS was low, was not different from the rate in non-CFS fatigued patients and was not related to disease severity or treatment outcome. In POTS-CFS adolescents, CBT was less successful than in non-POTS-CFS patients. The evaluation of POTS appears to be of limited value for the diagnosis of CFS.

Are Proactive and Reactive Aggression Meaningful Distinctions in Adolescents? A Variable- and Person-Based Approach.

This study was designed to examine whether proactive and reactive aggression are meaningful distinctions at the variable- and person-based level, and to determine their associated behavioral profiles. Data from 587 adolescents (mean age 15.6; 71.6 % male) from clinical samples of four different sites with differing levels of aggression problems were analyzed. A multi-level Latent Class Analysis (LCA) was conducted to identify classes of individuals (person-based) with similar aggression profiles based on factor scores (variable-based) of the Reactive Proactive Questionnaire (RPQ) scored by self-report. Associations were examined between aggression factors and classes, and externalizing and internalizing problem behavior scales by parent report (CBCL) and self-report (YSR). Factor-analyses yielded a three factor solution: 1) proactive aggression, 2) reactive aggression due to internal frustration, and 3) reactive aggression due to external provocation. All three factors showed moderate to high correlations. Four classes were detected that mainly differed quantitatively (no 'proactive-only' class present), yet also qualitatively when age was taken into account, with reactive aggression becoming more severe with age in the highest affected class yet diminishing with age in the other classes. Findings were robust across the four samples. Multiple regression analyses showed that 'reactive aggression due to internal frustration' was the strongest predictor of YSR and CBCL internalizing problems. However, results showed moderate to high overlap between all three factors. Aggressive behavior can be distinguished psychometrically into three factors in a clinical sample, with some differential associations. However, the clinical relevance of these findings is challenged by the person-based analysis showing proactive and reactive aggression are mainly driven by aggression severity.