Construct Validation of a Multidimensional Computerized Adaptive Test for Fatigue in Rheumatoid Arthritis

Objective Multidimensional computerized adaptive testing enables precise measurements of patient-reported outcomes at an individual level across different dimensions. This study examined the construct validity of a multidimensional computerized adaptive test (CAT) for fatigue in rheumatoid arthritis (RA). Methods The ‘CAT Fatigue RA’ was constructed based on a previously calibrated item bank. It contains 196 items and three dimensions: ‘severity’, ‘impact’ and ‘variability’ of fatigue. The CAT was administered to 166 patients with RA. They also completed a traditional, multidimensional fatigue questionnaire (BRAF-MDQ) and the SF-36 in order to examine the CAT’s construct validity. A priori criterion for construct validity was that 75% of the correlations between the CAT dimensions and the subscales of the other questionnaires were as expected. Furthermore, comprehensive use of the item bank, measurement precision and score distribution were investigated. Results The a priori criterion for construct validity was supported for two of the three CAT dimensions (severity and impact but not for variability). For severity and impact, 87% of the correlations with the subscales of the well-established questionnaires were as expected but for variability, 53% of the hypothesised relations were found. Eighty-nine percent of the items were selected between one and 137 times for CAT administrations. Measurement precision was excellent for the severity and impact dimensions, with more than 90% of the CAT administrations reaching a standard error below 0.32. The variability dimension showed good measurement precision with 90% of the CAT administrations reaching a standard error below 0.44. No floor- or ceiling-effects were found for the three dimensions. Conclusion The CAT Fatigue RA showed good construct validity and excellent measurement precision on the dimensions severity and impact. The dimension variability had less ideal measurement characteristics, pointing to the need to recalibrate the CAT item bank with a two-dimensional model, solely consisting of severity and impact

Chronic fatigue syndrome (CFS/ME) symptom-based phenotypes and 1-year treatment outcomes in two clinical cohorts of adult patients in the UK and The Netherlands

Objective: We previously described symptom-based chronic fatigue syndrome (CFS/ME) phenotypes in clinical assessment data from 7041 UK and 1392 Dutch adult CFS/ME patients. Here we aim to replicate these phenotypes in a more recent UK patient cohort, and investigate whether phenotypes are associated with 1-year treatment outcome. Methods: 12 specialist CFS/ME services (11 UK, 1 NL) recorded the presence/absence of 5 symptoms (muscle pain, joint pain, headache, sore throat, and painful lymph nodes) which can occur in addition to the 3 symptoms (post-exertional malaise, cognitive dysfunction, and disturbed/unrefreshing sleep) that are present for almost all patients. Latent Class Analysis (LCA) was used to assign symptom profiles (phenotypes). Multinomial logistic regression models were fitted to quantify associations between phenotypes and overall change in health 1 year after the start of treatment. Results: Baseline data were available for N = 918 UK and N = 1392 Dutch patients, of whom 416 (45.3%) and 912 (65.5%) had 1-year follow-up data, respectively. 3-and 4-class phenotypes identified in the previous UK patient cohort were replicated in the new UK cohort. UK patients who presented with 'polysymptomatic' and 'pain-only' phenotypes were 57% and 67% less likely (multinomial odds ratio (MOR) 0.43 (95% CI 0.19-0.94) and 0.33 (95% CI 0.13-0.84)) to report that their health was "very much better" or "much better" than patients who presented with an 'oligosymptomatic' phenotype. For Dutch patients, polysymptomatic and pain-only phenotypes were associated with 72% and 55% lower odds of improvement (MOR 0.28 (95% CI 0.11, 0.69) and 0.45 (95% CI 0.21, 0.99)) compared with oligosymptomatic patients. Conclusions: Adult CFS/ME patients with multiple symptoms or pain symptoms who present for specialist treatment are much less likely to report favourable treatment outcomes than patients who present with few symptom

Differential Role of gp130-Dependent STAT and Ras Signalling for Haematopoiesis Following Bone-Marrow Transplantation

INTRODUCTION: Bone marrow transplantation (BMT) is a complex process regulated by different cytokines and growth factors. The pleiotropic cytokine IL-6 (Interleukin-6) and related cytokines of the same family acting on the common signal transducer gp130 are known to play a key role in bone marrow (BM) engraftment. In contrast, the exact signalling events that control IL-6/gp130-driven haematopoietic stem cell development during BMT remain unresolved. METHODS: Conditional gp130 knockout and knockin mice were used to delete gp130 expression (gp130(ΔMx)), or to selectively disrupt gp130-dependent Ras (gp130(ΔMxRas)) or STAT signalling (gp130(ΔMxSTAT)) in BM cells. BM derived from the respective strains was transplanted into irradiated wildtype hosts and repopulation of various haematopoietic lineages was monitored by flow cytometry. RESULTS: BM derived from gp130 deficient donor mice (gp130(ΔMx)) displayed a delayed engraftment, as evidenced by reduced total white blood cells (WBC), marked thrombocytopenia and anaemia in the early phase after BMT. Lineage analysis unravelled a restricted development of CD4(+) and CD8(+) T-cells, CD19(+) B-cells and CD11b(+) myeloid cells after transplantation of gp130-deficient BM grafts. To further delineate the two major gp130-induced signalling cascades, Ras-MAPK and STAT1/3-signalling respectively, we used gp130(ΔMxRas) and gp130(ΔMxSTAT) donor BM. BMT of gp130(ΔMxSTAT) cells significantly impaired engraftment of CD4(+), CD8(+), CD19(+) and CD11b(+) cells, whereas gp130(ΔMxRas) BM displayed a selective impairment in early thrombopoiesis. Importantly, gp130-STAT1/3 signalling deficiency in BM grafts severely impaired survival of transplanted mice, thus demonstrating a pivotal role for this pathway in BM graft survival and function. CONCLUSION: Our data unravel a vital function of IL-6/gp130-STAT1/3 signals for BM engraftment and haematopoiesis, as well as for host survival after transplantation. STAT1/3 and ras-dependent pathways thereby exert distinct functions on individual bone-marrow-lineages

Items and dimensions for the construction of a multidimensional computerized adaptive test to measure fatigue in patients with rheumatoid arthritis

Objectives Development of an item pool to construct a future computerized adaptive test (CAT) for fatigue in rheumatoid arthritis (RA). The item pool was based on the patients' perspective and examined for face and content validity previously. This study assessed the fit of the items with seven predefined dimensions and examined the item pool's dimensionality structure in statistical terms. Study Design and Setting A total of 551 patients with RA participated in this study. Several steps were conducted to come from an explorative item pool to a psychometrically sound item bank. The item response theory (IRT) analysis using the generalized partial credit model was conducted for each of the seven predefined dimensions. Poorly fitting items were removed. Finally, the best possible multidimensional IRT (MIRT) model for the data was identified. Results In IRT analysis, 49 items showed insufficient item characteristics. Items with a discriminative ability below 0.60 and/or model misfit effect sizes greater than 0.10 were removed. Factor analysis on the 196 remaining items revealed three dimensions, namely severity, impact, and variability of fatigue. The dimensions were further confirmed in MIRT model analysis. Conclusion This study provided an initially calibrated item bank and showed which dimensions and items can be used for the development of a multidimensional CAT for fatigue in R

Targeted delivery of a phosphoinositide 3-kinase γ inhibitor to restore organ function in sepsis

Jaundice, the clinical hallmark of infection-associated liver dysfunction, reflects altered membrane organization of the canalicular pole of hepatocytes and portends poor outcomes. Mice lacking phosphoinositide 3-kinase-γ (PI3Kγ) are protected against membrane disintegration and hepatic excretory dysfunction. However, they exhibit a severe immune defect that hinders neutrophil recruitment to sites of infection. To exploit the therapeutic potential of PI3Kγ inhibition in sepsis, a targeted approach to deliver drugs to hepatic parenchymal cells without compromising other cells, in particular immune cells, seems warranted. Here, we demonstrate that nanocarriers functionalized through DY-635, a fluorescent polymethine dye, and a ligand of organic anion transporters can selectively deliver therapeutics to hepatic parenchymal cells. Applying this strategy to a murine model of sepsis, we observed the PI3Kγ-dependent restoration of biliary canalicular architecture, maintained excretory liver function, and improved survival without impairing host defense mechanisms. This strategy carries the potential to expand targeted nanomedicines to disease entities with systemic inflammation and concomitantly impaired barrier functionality

Charakteristika und Outcome von 70 beatmeten COVID-19-Patienten : Bilanz nach der ersten Welle an einem universitären Zentrum

BACKGROUND In a pandemic situation the overall mortality rate is of considerable interest; however, these data must always be seen in relation to the given healthcare system and the availability of local level of care. A recently published German data evaluation of more than 10,000 COVID-19 patients treated in 920 hospitals showed a high mortality rate of 22% in hospitalized patients and of more than 50% in patients requiring invasive ventilation. Because of the high infection rates in Bavaria, a large number of COVID-19 patients with considerable severity of disease were treated at the intensive care units of the LMU hospital. The LMU hospital is a university hospital and a specialized referral center for the treatment of patients with acute respiratory distress syndrome (ARDS). OBJECTIVE Data of LMU intensive care unit (ICU) patients were systematically evaluated and compared with the recently published German data. METHODS Data of all COVID-19 patients with invasive and noninvasive ventilation and with completed admission at the ICU of the LMU hospital until 31 July 2020 were collected. Data were processed using descriptive statistics. RESULTS In total 70 critically ill patients were included in the data evaluation. The median SAPS II on admission to the ICU was 62~points. The median age was 66 years and 81% of the patients were male. More than 90% were diagnosed with ARDS and received invasive ventilation. Treatment with extracorporeal membrane oxygenation (ECMO) was necessary in 10% of the patients. The median duration of ventilation was 16 days, whereby 34.3% of patients required a tracheostomy. Of the patients 27.1% were transferred to the LMU hospital from external hospitals with reference to our ARDS/ECMO program. Patients from external hospitals had ARDS of higher severity than the total study population. In total, nine different substances were used for virus-specific treatment of COVID-19. The most frequently used substances were hydroxychloroquine and azithromycin. Immunomodulatory treatment, such as Cytosorb® (18.6%) and methylprednisolone (25.7%) were also frequently used. The overall in-hospital mortality rate of ICU patients requiring ventilation was 28.6%. The mortality rates of patients from external hospitals, patients with renal replacement therapy and patients with ECMO therapy were 47.4%, 56.7% and 85.7%, respectively. CONCLUSION The mortality rate in the ventilated COVID-19 intensive care patients was considerably different from the general rate in Germany. The data showed that treatment in an ARDS referral center could result in a lower mortality rate. Low-dose administration of steroids may be another factor to improve patient outcome in a preselected patient population. In the authors' opinion, critically ill COVID-19 patients should be treated in an ARDS center provided that sufficient resources are available.ZUSAMMENFASSUNG HINTERGRUND: Eine aktuelle, deutschlandweite Datenerhebung zeigte bei beatmeten Patienten mit COVID-19 eine Letalität von über 50 %. Auch am LMU Klinikum wurde eine große Anzahl an Patienten mit COVID-19 mit teils erheblicher Erkrankungsschwere intensivmedizinisch behandelt. FRAGESTELLUNG Die Daten der am LMU-Klinikum behandelten COVID-19-Patienten wurden systematisch ausgewertet und mit den deutschlandweiten Daten verglichen. METHODIK Für die vorliegende Studie wurden die Daten aller Patienten, die bis zum 31.07.2020 am LMU-Klinikum aufgrund von COVID-19 invasiv und nichtinvasiv beatmet wurden und deren Krankenhausaufenthalt zum Zeitpunkt der Auswertung bereits abgeschlossen war, analysiert und mittels deskriptiver Statistik aufgearbeitet. ERGEBNISSE Insgesamt wurden 70 kritisch kranke, beatmete Patienten (SAPS-II-Median: 62 Punkte) analysiert (Altersmedian: 66 Jahre, 81 % männlich). Über 90 % wurden wegen eines akuten Lungenversagens (ARDS) unterschiedlicher Schweregrade behandelt. Eine Therapie mittels extrakorporaler Membranoxygenierung (ECMO) war bei 10 % erforderlich. Die Übernahme von externen Kliniken im Rahmen einer ARDS/ECMO-Anfrage erfolgte bei 27,1 % der Patienten. Häufig eingesetzte immunmodulatorische Therapien waren die Behandlung mit Cytosorb® (18,6 %) und die prolongierte Gabe von Methylprednisolon (25,7 %). Die krankenhausinterne Letalität betrug 28,6 %. FAZIT Trotz erheblicher Erkrankungsschwere lag die Letalität bei beatmeten COVID-19-Intensivpatienten im LMU-Kollektiv deutlich unter der deutschlandweit erhobenen Letalität. Ein möglicher Faktor ist die Behandlung in einem Zentrum für ARDS

Regulatory interactions between IRG resistance GTPases in the cellular response to Toxoplasma gondii

Members of the immunity-related GTPase (IRG) family are interferon-inducible resistance factors against a broad spectrum of intracellular pathogens including Toxoplasma gondii. The molecular mechanisms governing the function and regulation of the IRG resistance system are largely unknown. We find that IRG proteins function in a system of direct, nucleotide-dependent regulatory interactions between family members. After interferon induction but before infection, the three members of the GMS subfamily of IRG proteins, Irgm1, Irgm2 and Irgm3, which possess an atypical nucleotide-binding site, regulate the intracellular positioning of the conventional GKS subfamily members, Irga6 and Irgb6. Following infection, the normal accumulation of Irga6 protein at the parasitophorous vacuole membrane (PVM) is nucleotide dependent and also depends on the presence of all three GMS proteins. We present evidence that an essential role of the GMS proteins in this response is control of the nucleotide-bound state of the GKS proteins, preventing their GTP-dependent activation before infection. Accumulation of IRG proteins at the PVM has previously been shown to be associated with a block in pathogen replication: our results relate for the first time the enzymatic properties of IRG proteins to their role in pathogen resistance

Secreted Bacterial Effectors and Host-Produced Eiger/TNF Drive Death in a Salmonella-Infected Fruit Fly

Death by infection is often as much due to the host's reaction as it is to the direct result of microbial action. Here we identify genes in both the host and microbe that are involved in the pathogenesis of infection and disease in Drosophila melanogaster challenged with Salmonella enterica serovartyphimurium (S. typhimurium). We demonstrate that wild-type S. typhimurium causes a lethal systemic infection when injected into the hemocoel of D. melanogaster. Deletion of the gene encoding the secreted bacterial effector Salmonella leucine-rich (PslrP) changes an acute and lethal infection to one that is persistent and less deadly. We propose a model in which Salmonella secreted effectors stimulate the fly and thus cause an immune response that is damaging both to the bacteria and, subsequently, to the host. In support of this model, we show that mutations in the fly gene eiger, a TNF homolog, delay the lethality of Salmonella infection. These results suggest that S. typhimurium-infected flies die from a condition that resembles TNF-induced metabolic collapse in vertebrates. This idea provides us with a new model to study shock-like biology in a genetically manipulable host. In addition, it allows us to study the difference in pathways followed by a microbe when producing an acute or persistent infection