Background Hemophagocytic lymphohistiocytosis (HLH) is a rare though often fatal hyperinflammatory syndrome mimicking sepsis in the critically ill. Diagnosis relies on the HLH-2004 criteria and HScore, both of which have been developed in pediatric or adult non-critically ill patients, respectively. Therefore, we aimed to determine the sensitivity and specificity of HLH-2004 criteria and HScore in a cohort of adult critically ill patients. Methods In this further analysis of a retrospective observational study, patients ≥ 18 years admitted to at least one adult ICU at Charité – Universitätsmedizin Berlin between January 2006 and August 2018 with hyperferritinemia of ≥ 500 μg/L were included. Patients’ charts were reviewed for clinically diagnosed or suspected HLH. Receiver operating characteristics (ROC) analysis was performed to determine prediction accuracy. Results In total, 2623 patients with hyperferritinemia were included, of whom 40 patients had HLH. We found the best prediction accuracy of HLH diagnosis for a cutoff of 4 fulfilled HLH-2004 criteria (95.0% sensitivity and 93.6% specificity) and HScore cutoff of 168 (100% sensitivity and 94.1% specificity). By adjusting HLH-2004 criteria cutoffs of both hyperferritinemia to 3000 μg/L and fever to 38.2 °C, sensitivity and specificity increased to 97.5% and 96.1%, respectively. Both a higher number of fulfilled HLH-2004 criteria [OR 1.513 (95% CI 1.372–1.667); p <  0.001] and a higher HScore [OR 1.011 (95% CI 1.009–1.013); p <  0.001] were significantly associated with in-hospital mortality. Conclusions An HScore cutoff of 168 revealed a sensitivity of 100% and a specificity of 94.1%, thereby providing slightly superior diagnostic accuracy compared to HLH-2004 criteria. Both HLH-2004 criteria and HScore proved to be of good diagnostic accuracy and consequently might be used for HLH diagnosis in critically ill patients. Clinical trial registration The study was registered with www.ClinicalTrials.gov (NCT02854943) on August 1, 2016.

Objective: Hyperferritinemia is frequently seen in critically ill patients. A rather rare though life-threatening condition related to severely elevated ferritin is hemophagocytic lymphohistiocytosis. We analyze ferritin levels to differentiate hemophagocytic lymphohistiocytosis from other causes of hyperferritinemia in a mixed cohort of critically ill patients. Design: Retrospective observational study. Setting: Adult surgical, anesthesiologic, and medical ICUs of a university hospital. Patients: Critical care patients (≥ 18 yr old) admitted to any of the adult ICUs at Charité – Universitätsmedizin Berlin between January 2006 and August 2018 with at least one ferritin value and hyperferritinemia (≥ 500 µg/L). Interventions: None. Measurements and Main Results: Patients were categorized into hemophagocytic lymphohistiocytosis, sepsis, septic shock, and other diagnoses. These were further categorized into 17 subgroups. Hemophagocytic lymphohistiocytosis diagnosis was based on Hemophagocytic Lymphohistiocytosis-2004 criteria and the HScore. Of 2,623 patients with hyperferritinemia, 40 were considered to have hemophagocytic lymphohistiocytosis (1.52%). Maximum ferritin levels were highest in hemophagocytic lymphohistiocytosis patients compared with all other disease groups (each p < 0.001). Sepsis and septic shock patients had higher maximum ferritin levels than patients with other diagnoses (each p < 0.001). A maximum ferritin value of 9,083 µg/L was at 92.5% sensitivity and 91.9% specificity for hemophagocytic lymphohistiocytosis (area under the curve, 0.963; 95% CI, 0.949–0.978). Of all subgroups with other diagnoses, maximum ferritin levels were highest in patients with varicella-zoster virus, hepatitis, or malaria (median, 1,935, 1,928, and 1,587 µg/L, respectively). Maximum ferritin levels were associated with increased in-hospital mortality (odds ratio, 1.518 per log µg/L [95% CI, 1.384–1.665 per log µg/L]; p < 0.001). Conclusions: This is the largest study of patients with ferritin available in a mixed ICU cohort. Ferritin levels in patients with hemophagocytic lymphohistiocytosis, sepsis, septic shock, and other conditions were distinctly different, with the highest ferritin levels observed in hemophagocytic lymphohistiocytosis patients. Maximum ferritin of 9,083 µg/L showed high sensitivity and specificity and, therefore, may contribute to improved diagnosis of hemophagocytic lymphohistiocytosis in ICU. The inclusion of ferritin into the sepsis laboratory panel is warranted.

Objectives: Hemophagocytic lymphohistiocytosis is a cytokine release syndrome caused by uncontrolled immune activation resulting in multiple organ failure and death. In this systematic review, we aimed to analyze triggers, various treatment modalities, and mortality in critically ill adult hemophagocytic lymphohistiocytosis patients. Data Sources: MEDLINE database (PubMed) at October 20, 2019. Study Selection: Studies and case series of patients greater than or equal to 18 years old, of whom at least one had to be diagnosed with hemophagocytic lymphohistiocytosis and admitted to an ICU. Data Extraction: Source data of studies and case series were summarized and analyzed on an individual basis. Multivariable logistic regression analysis was performed adjusting for age, sex, and trigger groups. Each single treatment agent was entered as a dichotomous variable to determine treatments associated with survival, regardless if given alone or in combination. Data Synthesis: In total, 661 patients from 65 studies and case series were included. Overall mortality was 57.8%. Infections were the most frequent trigger (49.9%), followed by malignancies (28.0%), autoimmune diseases (12.1%), unknown triggers (9.4%), and drugs (0.6%). Treatment with IV immunoglobulins was associated with improved survival (odds ratio, 0.548; 95% CI, 0.337–0.891; p = 0.015), while treatment with cyclosporine was associated with increased risk of death (odds ratio, 7.571; 95% CI, 3.702–15.483; p < 0.001). Considering different trigger groups separately, same results occurred only for infection-triggered hemophagocytic lymphohistiocytosis. No information was available on disease severity and other confounding factors. Conclusions: Mortality of hemophagocytic lymphohistiocytosis in the ICU is high. Most common triggers were infections. Results of survival analyses may be biased by treatment indication and disease severity. Future studies prospectively investigating treatment tailored to critically ill hemophagocytic lymphohistiocytosis patients are highly warranted.

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Background: Hemophagocytic lymphohistiocytosis (HLH), an uncontrolled overactivation of the immune system, is well characterized in pediatric patients, yet, much less is known about this life-threatening condition in adult patients. As HLH is often complicated by organ failure, patients will require admission to the intensive care unit for organ support therapy. However, recognition of HLH patients in the intensive care unit (ICU) is challenged by the clinical overlap with sepsis. Here, we analyze HLH patients to better understand its clinical presentation, diagnosis, and treatment. Methods: For the purpose of this retrospective observational study, we searched for suspected and diagnosed adult HLH of all patients admitted to at least one adult surgical, anesthesiological or medical ICU between January 2006 and August 2018 at the university hospital Charité — Universitätsmedizin Berlin. All cases were reviewed by two HLH experts, who confirmed or declined the diagnosis. Results: Of 6,340 ICU patients with ferritin measurement, 40 suffered from HLH (0.63%). Of these, in-hospital mortality was 60.0% over all cases, which was highest in malignancy-associated HLH (71.4%). Infections were identified as most common triggers (42.5%). A variety of 19 different treatment strategies were applied. Non-survivors showed higher ferritin at diagnosis compared with survivors ( P = 0.021), which was also seen in multivariable analyses. A minimum ferritin of 4083 μg/L after diagnosis was most predictive for 30-day mortality (AUC 0.888, 95% CI 0.771–1.000; sensitivity 93.8%, specificity 78.9%). Conclusions: Mortality in adult HLH patients in the ICU is high, particularly in malignancy-associated HLH. Infections are the most frequent HLH triggers in critically ill patients. At present, there is no standardized treatment for HLH in adult patients available. Assessment of ferritin is valuable for diagnosis, prognosis, and treatment monitoring. Trial registration: The study was registered with www.ClinicalTrials.gov (NCT02854943) on August 1, 2016.

Asthma is a chronic inflammatory condition. Inhibition of the ubiquitin-proteasome system offers promise as a anti-inflammatory strategy, being responsible for the degradation of key proteins involved in crucial cellular functions, including gene expression in inflammation (e.g. inhibitory IkappaB-alpha and the endogenous MAPK deactivator - MKP-1). As MKP-1 inhibits MAPK-mediated pro-remodeling functions in human airway smooth muscle (ASM; a pivotal immunomodulatory cell in asthma) in this study we investigate the effect of the proteasome inhibitor MG-132 on MKP-1 and evaluate the anti-inflammatory effect of MG-132 on cytokine secretion from ASM cells. Examining the time-course of induction of MKP-1 mRNA and protein by MG-132 (10microM) we show that MKP-1 mRNA was first detected at 30min, increased to significant levels by 4h, resulting in a 12.6+/-1.5-fold increase in MKP-1 mRNA expression by 24h (P<0.05). MKP-1 protein levels corroborate the mRNA results. Investigating the effect of MG-132 on secretion of the cytokine IL-6 we show that while short-term pretreatment with MG-132 (30min) partially reduced TNFalpha-induced IL-6 via inhibition of IkappaB-alpha degradation and the NF-kappaB pathway, longer-term proteasome inhibition (up to 24h) robustly upregulated MKP-1 and was temporally correlated with repression of p38-mediated IL-6 secretion from ASM cells. Moreover, utilizing a cytokine array we show that MG-132 represses the secretion of multiple cytokines implicated in asthma. Taken together, our results demonstrate that MG-132 upregulates MKP-1 and represses cytokine secretion from ASM and highlight the potential of the proteasome as a therapeutic target in asthma.

Mitogen activated protein kinase phosphatase-1 (MKP-1) has emerged as an important protein mediating breast cancer oncogenesis and chemoresistance to cancer chemotherapies, especially proteasome inhibitors. In this in vitro study, we utilized the breast cancer epithelial cell lines MCF-7 and MDA-MB-231, in comparison to MCF-10A control cells, to examine the impact of MKP-1 on breast cancer cell growth and repression by proteasome inhibitors. We confirm that proteasome inhibitors MG-132 and bortezomib induce MKP-1 protein upregulation and we show that one of the ways in which bortezomib increases MKP-1 in breast cancer cells, in addition to inhibition of ubiquitin-proteasome system, is via upregulation of MKP-1 mRNA expression in p38 MAPK-mediated manner. Notably, these effects are specific to cancer cells, as bortezomib activated p38 MAPK and induced MKP-1 in MCF-7 and MDA-MB-231 breast cancer cells, but not in control cells (MCF-10A). We took a dual approach toward targeting MKP-1 to show that bortezomib-induced effects are enhanced. Firstly, treatment with the non-specific MKP-1 inhibitor triptolide reduces breast cancer cell growth and augments proteasome inhibitor-induced effects. Secondly, specific knock-down of MKP-1 with siRNA significantly repressed cell viability by reduced cyclin D1 expression, and enhanced repression of cancer cell growth by proteasome inhibitors. Taken together, these results indicate that removing the unwanted (MKP-1-inducing) effects of bortezomib significantly improves the efficacy of proteasome inhibition in breast cancer cells. Thus, future development of drugs targeting MKP-1 offer promise of combination therapies with reduced toxicity and enhanced cell death in breast cancer.

IntroductionHaemophagocytic lymphohistiocytosis (HLH) in adults is characterised by toxic immune activation and a sepsis-like syndrome, leading to high numbers of undiagnosed cases and mortality rates of up to 68%. Early diagnosis and specific immune suppressive treatment are mandatory to avoid fatal outcome, but the diagnostic criteria (HLH-2004) are adopted from paediatric HLH and have not been validated in adults. Experimental studies suggest biomarkers to sufficiently diagnose HLH. However, biomarkers for the diagnosis of adult HLH have not yet been investigated.Methods and analysisThe HEMICU (Diagnostic biomarkers for adult haemophagocytic lymphohistiocytosis in critically ill patients) study aims to estimate the incidence rate of adult HLH among suspected adult patients in intensive care units (ICUs). Screening for HLH will be performed in 16 ICUs of Charité – Universitätsmedizin Berlin. The inclusion criteria are bicytopaenia, hyperferritinaemia (≥500 µg/L), fever or when HLH is suspected by the clinician. Over a period of 2 years, we expect inclusion of about 100 patients with suspected HLH. HLH will be diagnosed if at least five of the HLH-2004 criteria are fulfilled, together with an expert review; all other included patients will serve as controls. Second, a panel of potential biomarker candidates will be explored. DNA, plasma and serum will be stored in a biobank. The primary endpoint of the study is the incidence rate of adult HLH among suspected adult patients during ICU stay. Out of a variety of measured biomarkers, this study furthermore aims to find highly potential biomarkers for the diagnosis of adult HLH in ICU. The results of this study will contribute to improved recognition and patient outcome of adult HLH in clinical routine.Ethics and disseminationThe institutional ethics committee approved this study on 1 August 2018 (Ethics Committee of Charité – Universitätsmedizin Berlin, EA4/006/18). The results of the study will be disseminated in an international peer-reviewed journal and presented at international conferences.Trial registration number NCT03510650.