Interleukin-1 Receptor Blockade Is Associated With Reduced Mortality in Sepsis Patients With Features of Macrophage Activation Syndrome: Reanalysis of a Prior Phase III Trial

Challenges in the diagnosis of hemophagocytic lymphohistiocytosis: Recommendations from the North American Consortium for Histiocytosis (NACHO)

Hemophagocytic lymphohistiocytosis (HLH) is a syndrome of pathologic immune activation, often associated with genetic defects of lymphocyte cytotoxicity. Though a distinctive constellation of features has been described for HLH, diagnosis remains challenging as patients have diverse presentations associated with a variety of triggers. We propose two concepts to clarify how HLH is diagnosed and treated: within the broader syndrome of HLH, "HLH disease" should be distinguished from "HLH disease mimics" and HLH subtypes should be categorized by specific etiologic associations, not the ambiguous dichotomy of "primary" and "secondary." We provide expert-based advice regarding the diagnosis and initiation of treatment for patients with HLH, rooted in improved understanding of its pathophysiology.

The innate immune perspective of autoimmune and autoinflammatory conditions

Innate immunity is one of two immune defence system arms. It is present at birth and does not require 'learning' through exposure to foreign organisms. It activates various mechanisms collectively to eliminate pathogens and hold an infection until the adaptive response are mounted. The innate immune system consists of four elements: the epithelial barrier, cells (e.g. macrophages, NK cells), plasma proteins (e.g. complement) and cytokines. These components act in concert to induce complex processes, as well as recruitment, activation and differentiation of adaptive responses. The innate response is more than just the 'first line of defence', as it essentially withholds the vast majority of any intruder, has a complex interplay with the adaptive arm and is crucial for survival of the host. Finally, yet importantly, a myriad of diseases has been linked with innate immune dysregulation. In this mini-review we will shed some light on these conditions, particularly regarding autoinflammatory ones.

Macrophage activation syndrome in adults: recent advances in pathophysiology, diagnosis and treatment

Haemophagocytic lymphohistiocytosis (HLH) is a hyperinflammatory syndrome, which if not promptly treated, can lead rapidly to critical illness and death. HLH is termed macrophage activation syndrome (MAS) when associated with rheumatic disease (where it is best characterized in systemic JIA) and secondary HLH (sHLH) when associated with other triggers including malignancy and infection. MAS/sHLH is rare and coupled with its mimicry of other conditions, is underrecognized. These inherent challenges can lead to diagnostic and management challenges in multiple medical specialties including haematology, infectious diseases, critical care and rheumatology. In this review we highlight the pathogenesis of MAS/sHLH including its underlying triggers, key clinical features and diagnostic challenges, prognostic factors and current treatments in adults.

DNA Viremia Is Associated with Hyperferritinemia in Pediatric Sepsis

OBJECTIVE

To evaluate the relationship between detection of DNA viruses, ferritin, and outcomes in children with severe sepsis.

STUDY DESIGN

We enrolled 75 pediatric patients with severe sepsis admitted to a tertiary care children's hospital. Plasma ferritin was measured within 48 hours of diagnosis and subsequently twice weekly. Herpes simplex type 1, human herpesvirus 6, Epstein-Barr virus, cytomegalovirus, and adenovirus DNAemia were assessed by polymerase chain reaction.

RESULTS

The incidence of DNAemia was increased significantly in patients with ferritin ≥1000 ng/mL (78% vs 28%; P < .05). Patients with ferritin ≥1000 ng/mL were more likely to have multiple DNA viruses detected in plasma (39% vs 4%; P < .001). The number of viruses detected in plasma directly correlated with the degree of hyperferritinemia and development of combined hepatobiliary and hematologic dysfunction after we controlled for bacterial and fungal coinfections (P < .05) as well as increased mortality after we controlled for severity of illness and cancer diagnosis (OR 2.6, 95% CI 1.1-6.3, P < .05).

CONCLUSIONS

Viral DNAemia was associated with hyperferritinemia and adverse outcome in pediatric severe sepsis. Prospective studies are needed to determine whether hyperferritinemia may be used to identify patients at risk of occult DNAemia.

Hemophagocytic Lymphohistiocytosis: Potentially Underdiagnosed in Intensive Care Units

BACKGROUND

Hemophagocytic lymphohistiocytosis in adults (aHLH) is a rare life-threatening hyperinflammatory syndrome caused by excessive activation of macrophages and CD8+ T-cells. Due to the clinical overlap with severe sepsis, aHLH often remains undiagnosed resulting in poor outcome. Here, we present a retrospective study of incidence, clinical findings, and the outcome of aHLH in intensive care units (ICUs).

METHODS

This retrospective analysis was performed at the university hospital Charité - Universitätsmedizin Berlin. We gathered data from 556 out of 46,532 patients admitted to our anesthesiological ICUs between 2006 and 2013, who had at least one plasma ferritin measurement during ICU treatment, and were at least 18 years old. Of these, 244 patients with ferritin at least 500 μg/L and available datasets of at least 4 HLH-2004 criteria were included. HLH-2004 diagnostic criteria and the recently published HScore were used. An aHLH expert team retrospectively reviewed the potential aHLH cases.

RESULTS

Seventy-one of the included 244 patients died; 9 out of the 244 patients were retrospectively classified as aHLH of whom 4 patients had died (44.4%). Two of the 9 aHLH patients had been correctly diagnosed and had received specific aHLH treatment. Thus, 7 out of 9 patients (77.8%) remained undetected. ICU patients with at least 1 captured ferritin value and hyperferritinemia showed an aHLH rate of 3.7%, which rises up to 5.6% when only deceased patients are considered. Mortality in this selected cohort is 44.4%.

CONCLUSIONS

Overall, 7 out of 9 patients (77.8%) suffering from aHLH remained undiagnosed. Awareness of this life-threatening syndrome, especially in ICUs, should be raised. The inclusion of ferritin into the admission lab panel for ICU is warranted.Clinical trial registered with www.ClinicalTrials.gov (NCT02854943) on August 1, 2016. As this is a retrospective study, trial registration was after final data collection date.

Precision Medicine in Critical Illness: Sepsis and Acute Respiratory Distress Syndrome

Sepsis and the acute respiratory distress syndrome (ARDS) each cause substantial morbidity and mortality. In contrast to other lung diseases, the entire course of disease in these syndromes is measured in days to weeks rather than months to years, which raises unique challenges in achieving precision medicine. We review advances in sepsis and ARDS resulting from omics studies, including those involving genome-wide association, gene expression, targeted proteomics, and metabolomics approaches. We focus on promising evidence of biological subtypes in both sepsis and ARDS that consistently display high risk for death. In sepsis, a gene expression signature with dysregulated adaptive immune signaling has evidence for a differential response to systemic steroid therapy, whereas in ARDS, a hyperinflammatory pattern identified in plasma using targeted proteomics responded more favorably to randomized interventions including high positive end-expiratory pressure, volume conservative fluid therapy, and simvastatin therapy. These early examples suggest heterogeneous biology that may be challenging to detect by clinical factors alone and speak to the promise of a precision approach that targets the right treatment at the right time to the right patient.

Unsupervised Analysis of Transcriptomics in Bacterial Sepsis Across Multiple Datasets Reveals Three Robust Clusters

OBJECTIVES

To find and validate generalizable sepsis subtypes using data-driven clustering.

DESIGN

We used advanced informatics techniques to pool data from 14 bacterial sepsis transcriptomic datasets from eight different countries (n = 700).

SETTING

Retrospective analysis.

SUBJECTS

Persons admitted to the hospital with bacterial sepsis.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

A unified clustering analysis across 14 discovery datasets revealed three subtypes, which, based on functional analysis, we termed "Inflammopathic, Adaptive, and Coagulopathic." We then validated these subtypes in nine independent datasets from five different countries (n = 600). In both discovery and validation data, the Adaptive subtype is associated with a lower clinical severity and lower mortality rate, and the Coagulopathic subtype is associated with higher mortality and clinical coagulopathy. Further, these clusters are statistically associated with clusters derived by others in independent single sepsis cohorts.

CONCLUSIONS

The three sepsis subtypes may represent a unifying framework for understanding the molecular heterogeneity of the sepsis syndrome. Further study could potentially enable a precision medicine approach of matching novel immunomodulatory therapies with septic patients most likely to benefit.

Interleukin-1 Family Cytokines: Keystones in Liver Inflammatory Diseases

The pyrogenic property being the first activity described, members of the interleukin-1 superfamily (IL-1α, IL-1β, IL-18, and the newest members: IL-33, IL-36, IL-37, and IL-38) are now known to be involved in several inflammatory diseases such as obesity, atherosclerosis, cancer, viral and parasite infections, and auto-inflammatory syndromes as well as liver diseases. Inflammation processes are keystones of chronic liver diseases, of which the etiology may be viral or toxic, as in alcoholic or non-alcoholic liver diseases. Inflammation is also at stake in acute liver failure involving massive necrosis, and in ischemia-reperfusion injury in the setting of liver transplantation. The role of the IL-1 superfamily of cytokines and receptors in liver diseases can be either protective or pro-inflammatory, depending on timing and the environment. Our review provides an overview of current understanding of the IL-1 family members in liver inflammation, highlighting recent key investigations, and therapeutic perspectives. We have tried to apply the concept of trained immunity to liver diseases, based on the role of the members of the IL-1 superfamily, first of all IL-1β but also IL-18 and IL-33, in modulating innate lymphoid immunity carried by natural killer cells, innate lymphoid cells or innate T-αβ lymphocytes.

[Hemophagocytic lymphohistiocytosis in unspecific virus infection]

Die Hämophagozytische Lymphohistiozytose (HLH), in der Literatur auch Hämophagozytosesyndrom oder Makrophagenaktivierungssyndrom im Rahmen einer rheumatologischen Vorerkrankung, wird auf Intensivstationen aufgrund des sepsisähnlichen Krankheitsbildes in über 70 % der Fälle nicht erkannt. Es wird von einem 30-jährigen, zuvor gesunden Patienten berichtet, der nach einer 3‑monatigen Asien- und Südamerikareise mit unklarem Fieber zunächst auf die infektiologische Normalstation der Charité – Universitätsmedizin Berlin aufgenommen und nach 3 Tagen bei respiratorischer Insuffizienz auf die Intensivstation verlegt wurde. Durch die sofortige HLH-Diagnostik mit Initiierung der spezifischen immunsupprimierenden Therapie mittels Dexamethason, Immunglobulinen und Anakinra konnte der Patient nach insgesamt 14-tägigem Krankenhausaufenthalt vollständig genesen in die Häuslichkeit entlassen werden. Es werden weiterhin aktuelle diagnostische und therapeutische Möglichkeiten diskutiert. Ferritin als entscheidender diagnostischer Marker sollte bei jedem Patienten mit unklarem Organversagen bestimmt werden.

Evaluation of macrophage activation syndrome in hospitalised patients with Kikuchi-Fujimoto disease based on the 2016 EULAR/ACR/PRINTO classification criteria

BACKGROUND

To evaluate the impact of macrophage activation syndrome (MAS) on clinical features in patients with Kikuchi-Fujimoto disease (KFD) and to compare the features of MAS in KFD with those of adult-onset Still's disease (AOSD) and systemic lupus erythematosus (SLE).

METHODS

The medical records of febrile patients hospitalised with KFD between November 2005 and April 2017 were reviewed. Patients fulfilling the 2016 classification criteria for MAS were classified as having MAS. Clinical and laboratory features of patients with KFD with and without MAS were evaluated. Poor hospitalisation outcomes were defined as intensive care unit admission or in-hospital mortality. The treatment outcomes of MAS in KFD, AOSD, and SLE were also compared.

RESULTS

Among 78 patients hospitalised with KFD, 24 (30.8%) patients had MAS during admission. Patients with KFD and MAS more frequently required glucocorticoid treatment (66.7% vs 40.7%, p = 0.036) and had longer hospital stays than patients with KFD without MAS (12.5 vs 8.5 days, p<0.001). In addition, patients with MAS had worse hospitalisation outcomes than patients without MAS (29.2% vs. 0.0%, p<0.001). Among patients with MAS in KFD, AOSD, and SLE, the number of patients requiring glucocorticoid treatment after 3 months was significantly lower among patients with MAS and KFD (KFD 33.3%, AOSD 88.9%, SLE 100%, p<0.001).

CONCLUSIONS

The presence of MAS in KFD was associated with adverse clinical outcomes including higher steroid usage and worse hospitalisation outcomes. However, compared to those with AOSD and SLE, patients with MAS and KFD were less likely to require long-term glucocorticoid treatment.

Prescribing motivations and patients' characteristics related to the use of biologic drugs in adult-onset Still's disease: analysis of a multicentre "real-life" cohort

A growing body of evidence suggests the usability of biologic disease-modifying anti-rheumatic drugs (bDMARDs) in treating adult-onset Still's disease (AOSD). In a multicentre "real-life" cohort, the physicians' prescribing motivations and patients' predictive characteristics of being treated with bDMARDs were assessed. Patients with AOSD, who were included in GIRRCS (Gruppo Italiano di Ricerca in Reumatologia Clinica e Sperimentale) cohort and treated with bDMARDs, were retrospectively assessed. Relevant data were collected by a review of clinical charts. Forty-four patients treated with bDMARDs were analysed, with slight male preponderance (52.3%) and a mean age of 39.3 ± 15.2 years. All patients were treated with corticosteroids (CCSs) (38.6% with low dosage) and 93.2% were treated with synthetic DMARDs (sDMARDs). Regarding the effectiveness of the first-line bDMARD, 65.6% of patients experienced a complete remission, defined as complete disappearance of both systemic and joint symptoms and normalisation of laboratory evidence of disease. The physicians' prescribing motivations for bDMARDs were inadequate response to CCSs and/or sDMARDs, CCS-sparing effect and occurrence of macrophage activation syndrome (MAS). Analysing patients' characteristics, chronic disease course (OR 3.09; 95%CI 1.22-7.80, p = 0.017), defined as disease with persistent symptoms, was predictive of being treated with bDMARDs, whereas age (OR 0.97, 95%CI 0.93-0.99, p = 0.048) was negatively associated, suggesting younger age as a further predictive factor. Patients with AOSD were treated with bDMARDs for inadequate response to CCSs and/or sDMARDs, CCS-sparing effect and MAS occurrence. Younger age and chronic disease course were patients' predictive characteristics of being treated with bDMARDs.

Convergent pathways of the hyperferritinemic syndromes

Hyperferritinemia and pronounced hemophagocytosis help distinguish a subset of patients with a particularly inflammatory and deadly systemic inflammatory response syndrome. Two clinically similar disorders typify these hyperferritinemic syndromes: hemophagocytic lymphohistiocytosis (HLH) and macrophage activation syndrome (MAS). HLH is canonically associated with a complete disturbance of perforin/granzyme-mediated cytotoxicity, whereas MAS occurs in the context of the related rheumatic diseases systemic juvenile idiopathic arthritis and adult-onset Still's disease, with associated IL-1 family cytokine activation. In practice, however, there are accumulating lines of evidence for innate immune dysregulation in HLH as well as partial impairments of cytotoxicity in MAS, and these mechanisms likely represent only a fraction of the host and environmental factors driving hyperferritinemic inflammation. Herein, we present new findings that highlight the pathogenic differences between HLH and MAS, two conditions that present with life-threatening hyperinflammation, hyperferritinemia and hemophagocytosis.

The role of interleukin-1 in general pathology

Interleukin-1, an inflammatory cytokine, is considered to have diverse physiological functions and pathological significances and play an important role in health and disease. In this decade, interleukin-1 family members have been expanding and evidence is accumulating that highlights the importance of interleukin-1 in linking innate immunity with a broad spectrum of diseases beyond inflammatory diseases. In this review, we look back on the definition of "inflammation" in traditional general pathology and discuss new insights into interleukin-1 in view of its history and the molecular bases of diseases, as well as current progress in therapeutics.

Neutrophil pyroptosis: new perspectives on sepsis

Pyroptosis is a caspase-1 or caspase-4/5/11-dependent programmed cell death associated with inflammation, which is initiated by inflammasomes or cytosolic LPS in innate immunity. Sepsis is a life-threatening organ dysfunction caused by an imbalance in the body's response to infection. It is a complex interaction between the pathogen and the host's immune system. Neutrophils play the role of a double-edged sword in sepsis, and a number of studies have previously shown that regulation of neutrophils is the most crucial part of sepsis treatment. Pyroptosis is one of the important forms for neutrophils to function, which is increasingly understood as a host active immune response. There is ample evidence that neutrophil pyroptosis may play an important role in sepsis. In recent years, a breakthrough in pyroptosis research has revealed the main mechanism of pyroptosis. However, the potential value of neutrophil pyroptosis in the treatment of sepsis did not draw enough attention. A literature review was performed on the main mechanism of pyroptosis in sepsis and the potential value of neutrophils pyroptosis in sepsis, which may be suitable targets for sepsis treatment in future.

Actualités sur le sepsis et le choc septique de l’enfant

L’incidence du sepsis de l’enfant augmente en réanimation pédiatrique. La définition du sepsis et du choc septique de l’enfant est amenée à évoluer à l’instar de celle du choc septique de l’adulte pour détecter les patients nécessitant une prise en charge urgente et spécialisée. La prise en charge d’un patient septique repose sur une oxygénothérapie, une expansion volémique au sérum salé isotonique, une antibiothérapie et un transfert dans un service de réanimation ou de surveillance continue pédiatrique. Le taux et la cinétique d’élimination du lactate plasmatique est un bon critère diagnostic et pronostic qui permet de guider la prise en charge. La présence de plusieurs défaillances d’organes ou une défaillance circulatoire aiguë signe le diagnostic de sepsis encore dit sévère, et leur persistance et/ou la non-correction de l’hypotension artérielle malgré un remplissage vasculaire d’au moins 40 ml/kg définit le choc septique chez l’enfant. Dans ce cas, la correction rapide de l’hypotension artérielle persistante repose sur la noradrénaline initiée sur une voie intraveineuse périphérique dans l’attente d’un accès veineux central. L’échographie cardiaque est un examen clé de l’évaluation hémodynamique du patient, pour guider la poursuite de l’expansion volémique ou détecter une cardiomyopathie septique. Des thérapeutiques additionnelles ont été proposées pour prendre en charge certains patients avec des défaillances d’organes particulières. L’immunomonitorage et la modulation sont un ensemble de techniques qui permettent la recherche et le traitement de certaines complications. La Surviving Sepsis Campaign a permis d’améliorer la prise en charge de ces patients par l’implémentation d’algorithmes de détection et de prise en charge du sepsis de l’enfant. Une révision pédiatrique de cette campagne est attendue prochainement.

TnI and IL-18 levels are associated with prognosis of sepsis

AIM

To evaluate the diagnostic value of interleukin-18 (IL-18) and troponin (TnI) in sepsis.

METHODS

This retrospective analysis included 117 patients with sepsis (patient group) and 92 subjects who attended regular physical examinations (control group). We compared IL-18 and TnI expressions before treatment (T1) and on day 5 (T2), day 10 (T3) and day 15 (T4) of treatment. Acute Physiology and Chronic Health Evaluation II (APACHE II) guidelines were used to analyse the correlation between IL-18, TnI and APACHE II scores.

RESULTS

At T1, T2, T3 and T4, the IL-18 and TnI levels were all higher in the patient group than in the control group (p<0.001). In the patient group, peak IL-18 and TnI levels were noted at T1, followed by T2, T3 and T4 (p<0.001). The linear correlation analysis revealed positive correlations between IL-18 and TnI levels and APACHE II score (r =0.759, 0.866, p <0.001). The 3-year survival rates of subjects with high IL-18 or TnI expression levels were all lower than of those with low expression levels (p=0.047, 0.048). In patients with sepsis, the expression of TnI and IL-18 is high and is positively correlated with APACHE II scores.

CONCLUSIONS

Monitoring TnI and IL-18 levels can effectively evaluate the severity and recovery of patients with sepsis.

Gasdermin D (GSDMD) as a new target for the treatment of infection

The discovery of a previously unknown protein, gasdermin D (GSDMD), as the key effector that leads to pyroptosis and NETosis has created much excitement. Since its initial report in Oct. 2015, more than 200 papers have been published on studies of the structure and mechanism of GSDMD and its homologues. The clear connection between infection and inflammasome activation made GSDMD a promising target for the development of anti-infection treatment. In this mini review, we discuss first the current understanding of the structure and mechanism of GSDMD, focusing on its potential as a druggable target, and then recent efforts in the development of inhibitors to interfere with the pore-forming function of GSDMD and thus alleviate the detrimental effects due to pyroptotic cell death.

Prevalence and Outcome of Secondary Hemophagocytic Lymphohistiocytosis Among SIRS Patients: Results from a Prospective Cohort Study

Secondary hemophagocytic lymphohistiocytosis (sHLH) is a life-threatening condition clinically presenting as SIRS (Systemic Inflammatory Response Syndrome). However, there is no comprehensive data concerning diagnostic algorithms, prevalence, outcome and biomarker performance in SIRS patients. We conducted a prospective observational cohort study on 451 consecutive patients fulfilling ≥2 SIRS criteria. The Hscore and the HLH-2004 criteria were used to determine the presence of sHLH, and the correlation of the screening-biomarkers ferritin, sCD25, and sCD163 with both scores was assessed. Out of 451 standard-care SIRS patients, five patients had high Hscores (≥169), suggesting incipient or HLH-like disease, and these patients were in urgent need for intensified therapy. However, none of these patients fulfilled five HLH-2004 criteria required for formal diagnosis. From the studied biomarkers, ferritin correlated strongest to both the HLH-2004 criteria and the Hscore (rs = 0.72, 0.41, respectively), and was the best predictor of 30-day survival (HR:1.012 per 100 μg/L, 95% CI: 1.004-1.021), when adjusted for patient's age, sex, bacteremia and malignant underlying-disease. Also, the HLH-2004 (HR per point increase: 1.435, 95% CI: 1.1012-2.086) and the Hscore (HR per point increase:1.011, 95% CI: 1.002-1.020) were independent predictors of 30-day-survival. The Hscore detected patients in hyperinflammatory states requiring urgent therapy escalation. Degrees of hyperinflammation, as assessed by ferritin and both HLH scores, are associated with worse outcomes.

Recommendations for the management of hemophagocytic lymphohistiocytosis in adults

Hemophagocytic lymphohistiocytosis (HLH) is a severe hyperinflammatory syndrome induced by aberrantly activated macrophages and cytotoxic T cells. The primary (genetic) form, caused by mutations affecting lymphocyte cytotoxicity and immune regulation, is most common in children, whereas the secondary (acquired) form is most frequent in adults. Secondary HLH is commonly triggered by infections or malignancies but may also be induced by autoinflammatory/autoimmune disorders, in which case it is called macrophage activation syndrome (MAS; or MAS-HLH). Most information on the diagnosis and treatment of HLH comes from the pediatric literature. Although helpful in some adult cases, this raises several challenges. For example, the HLH-2004 diagnostic criteria developed for children are commonly applied but are not validated for adults. Another challenge in HLH diagnosis is that patients may present with a phenotype indistinguishable from sepsis or multiple organ dysfunction syndrome. Treatment algorithms targeting hyperinflammation are frequently based on pediatric protocols, such as HLH-94 and HLH-2004, which may result in overtreatment and unnecessary toxicity in adults. Therefore, dose reductions, individualized tailoring of treatment duration, and an age-dependent modified diagnostic approach are to be considered. Here, we present expert opinions derived from an interdisciplinary working group on adult HLH, sponsored by the Histiocyte Society, to facilitate knowledge transfer between physicians caring for pediatric and adult patients with HLH, with the aim to improve the outcome for adult patients affected by HLH.

How Clinical Flow Cytometry Rebooted Sepsis Immunology

On May 2017, the World Health Organization (WHO) recognized sepsis as a global health priority by adopting a resolution to improve the prevention, diagnosis, and management of this deadly disease. While it has long been known that sepsis deeply perturbs immune homeostasis by inducing a tremendous systemic inflammatory response, pivotal observations based on clinical flow cytometry indicate that sepsis indeed initiates a more complex immune response that varies over time, with the concomitant occurrence of both pro- and anti-inflammatory mechanisms. As a resultant, some septic patients enter a stage of protracted immunosuppression. This paved the way for immunostimulation approaches in sepsis. Clinical flow cytometry permitted this evolution by drawing a new picture of pathophysiology and reshaping immune trajectories in patients. Additional information from cytometry by time of flight mass cytometry and other high-dimensional flow cytometry platform should rapidly enrich our understanding of this complex disease. This review reports on landmarks of clinical flow cytometry in sepsis and how this single-cell analysis technique permitted to breach the wall of decades of unfruitful anti-inflammatory-based clinical trials in sepsis. © 2019 International Society for Advancement of Cytometry.

Calm in the midst of cytokine storm: a collaborative approach to the diagnosis and treatment of hemophagocytic lymphohistiocytosis and macrophage activation syndrome

BACKGROUND

Hemophagocytic lymphohistiocytosis (HLH) and macrophage activation syndrome (MAS) were historically thought to be distinct entities, often managed in isolation. In fact, these conditions are closely related. A collaborative approach, which incorporates expertise from subspecialties that previously treated HLH/MAS independently, is needed. We leveraged quality improvement (QI) techniques in the form of an Evidence-Based Guideline (EBG) to build consensus across disciplines on the diagnosis and treatment of HLH/MAS.

METHODS

A multidisciplinary work group was convened that met monthly to develop the HLH/MAS EBG. Literature review and expert opinion were used to develop a management strategy for HLH/MAS. The EBG was implemented, and quality metrics were selected to monitor outcomes.

RESULTS

An HLH/MAS clinical team was formed with representatives from subspecialties involved in the care of patients with HLH/MAS. Broad entry criteria for the HLH/MAS EBG were established and included fever and ferritin ≥500 ng/mL. The rheumatology team was identified as the "gate-keeper," charged with overseeing the diagnostic evaluation recommended in the EBG. First-line medications were recommended based on the acuity of illness and risk of concurrent infection. Quality metrics to be tracked prospectively based on time to initiation of treatment and clinical response were selected.

CONCLUSION

HLH/MAS are increasingly considered to be a spectrum of related conditions, and joint management across subspecialties could improve patient outcomes. Our experience in creating a multidisciplinary approach to HLH/MAS management can serve as a model for care at other institutions.

Macrophage Activation-Like Syndrome: A Distinct Entity Leading to Early Death in Sepsis

Hemophagocytic lymphohistocytosis (HLH) is characterized by fulminant cytokine storm leading to multiple organ dysfunction and high mortality. HLH is classified into familial (fHLH) and into secondary (sHLH). fHLH is rare and it is due to mutations of genes encoding for perforin or excretory granules of natural killer (NK) cells of CD8-lymphocytes. sHLH is also known as macrophage activation syndrome (MAS). Macrophage activation syndrome (MAS) in adults is poorly studied. Main features are fever, hepatosplenomegaly, hepatobiliary dysfunction (HBD), coagulopathy, cytopenia of two to three cell lineages, increased triglycerides and hemophagocytosis in the bone marrow. sHLH/MAS complicates hematologic malignancies, autoimmune disorders and infections mainly of viral origin. Pathogenesis is poorly understood and it is associated with increased activation of macrophages and NK cells. An autocrine loop of interleukin (IL)-1β over-secretion leads to cytokine storm of IL-6, IL-18, ferritin, and interferon-gamma; soluble CD163 is highly increased from macrophages. The true incidence of sHLH/MAS among patients with sepsis has only been studied in the cohort of the Hellenic Sepsis Study Group. Patients meeting the Sepsis-3 criteria and who had positive HSscore or co-presence of HBD and disseminated intravascular coagulation (DIC) were classified as patients with macrophage activation-like syndrome (MALS). The frequency of MALS ranged between 3 and 4% and it was an independent entity associated with early mortality after 10 days. Ferritin was proposed as a diagnostic and surrogate biomarker. Concentrations >4,420 ng/ml were associated with diagnosis of MALS with 97.1% specificity and 98% negative predictive value. Increased ferritin was also associated with increased IL-6, IL-18, IFNγ, and sCD163 and by decreased IL-10/TNFα ratio. A drop of ferritin by 15% the first 48 h was a surrogate finding of favorable outcome. There are 10 on-going trials in adults with sHLH; two for the development of biomarkers and eight for management. Only one of them is focusing in sepsis. The acronym of the trial is PROVIDE (ClinicalTrials.gov NCT03332225) and it is a double-blind randomized clinical trial aiming to deliver to patients with septic shock treatment targeting their precise immune state. Patients diagnosed with MALS are receiving randomized treatment with placebo or the IL-1β blocker anakinra.

Immune Modulation in Pediatric Sepsis

The initial host immune response to sepsis in children is characterized by a proinflammatory surge that can be associated with fever, capillary leak, and organ dysfunction. There is, however, a concurrent anti-inflammatory response that results in hyporesponsiveness of innate and adaptive immune cells. When severe, this response is termed immunoparalysis and is known to be associated with prolonged organ dysfunction, increased risk for nosocomial infection, and death in septic adults and children. Sepsis-induced immune suppression can be defined in the laboratory by reduced whole blood ex vivo - stimulated cytokine production capacities, reduced expression of human leukocyte antigen (HLA)-DR on circulating monocytes, and reduced absolute cell counts. While anti-inflammatory therapies have largely been unsuccessful at improving outcomes from adult and pediatric sepsis, the use of immunostimulatory therapies such as granulocyte macrophage colony-stimulating factor (GM-CSF) in patients with sepsis-induced immunoparalysis shows promise. A greater understanding of the risk factors for immunoparalysis along with the development and execution of immunophenotype-specific clinical trials of strategies to optimize innate and adaptive immune function are needed to further improve outcomes in septic children.

Endothelial Dysfunction Is Associated with Mortality and Severity of Coagulopathy in Patients with Sepsis and Disseminated Intravascular Coagulation

The role of the endothelium in sepsis-associated disseminated intravascular coagulation (DIC) is multifaceted and may contribute substantially to disease severity and outcome. The purpose of this study was to quantify measures of endothelial function, including markers of activation (endocan, Angiopoietin-2 [Ang-2], and von Willebrand Factor), endogenous anticoagulants (tissue factor pathway inhibitor and protein C), and damage-associated factors (High Mobility Group Box 1 [HMGB-1]) in the plasma of patients with sepsis and DIC, and to determine the relationship of these factors with severity of illness and outcome. Plasma samples were collected from 103 adult patients with sepsis within 48 hours of intensive care unit admission. Biomarker levels were measured using commercially available, standardized methods. Disseminated intravascular coagulation was diagnosed according to the International Society of Thrombosis and Hemostasis scoring algorithm. Twenty-eight-day mortality was used as the primary end point. In this study, endothelial damage and dysfunction were associated with the severity of coagulopathy and mortality in DIC patients. Loss of the endogenous anticoagulant protein C and elevation in the vascular regulator Ang-2 were associated with the development of overt DIC. In addition to Ang-2 and protein C, endocan, a biomarker of endothelial activation, and HMGB-1, a mediator of endothelial damage and activation, were significantly associated with mortality. This underscores the contribution of the endothelium to the pathogenesis of sepsis-associated DIC.

Part I: Minimum Quality Threshold in Preclinical Sepsis Studies (MQTiPSS) for Study Design and Humane Modeling Endpoints

Preclinical animal studies are mandatory before new treatments can be tested in clinical trials. However, their use in developing new therapies for sepsis has been controversial because of limitations of the models and inconsistencies with the clinical conditions. In consideration of the revised definition for clinical sepsis and septic shock (Sepsis-3), a Wiggers-Bernard Conference was held in Vienna in May 2017 to propose standardized guidelines on preclinical sepsis modeling. The participants conducted a literature review of 260 most highly cited scientific articles on sepsis models published between 2003 and 2012. The review showed, for example, that mice were used in 79% and euthanasia criteria were defined in 9% of the studies. Part I of this report details the recommendations for study design and humane modeling endpoints that should be addressed in sepsis models. The first recommendation is that survival follow-up should reflect the clinical time course of the infectious agent used in the sepsis model. Furthermore, it is recommended that therapeutic interventions should be initiated after the septic insult replicating clinical care. To define an unbiased and reproducible association between a new treatment and outcome, a randomization and blinding of treatments as well as inclusion of all methodological details in scientific publications is essential. In all preclinical sepsis studies, the high standards of animal welfare must be implemented. Therefore, development and validation of specific criteria for monitoring pain and distress, and euthanasia of septic animals, as well as the use of analgesics are recommended. A set of four considerations is also proposed to enhance translation potential of sepsis models. Relevant biological variables and comorbidities should be included in the study design and sepsis modeling should be extended to mammalian species other than rodents. In addition, the need for source control (in case of a defined infection focus) should be considered. These recommendations and considerations are proposed as "best practices" for animal models of sepsis that should be implemented.

Pharmacological preconditioning with the cellular stress inducer thapsigargin protects against experimental sepsis

Previous studies have shown that pretreatment with thapsigargin (TG), a cellular stress inducer, produced potent protective actions against various pathologic injuries. So far there is no information on the effects of TG on the development of bacterial sepsis. Using lipopolysaccharides- and cecal ligation/puncture-induced sepsis models in mice, we demonstrated that preconditioning with a single bolus administration of TG conferred significant improvements in survival. The beneficial effects of TG were not mediated by ER stress induction or changes in Toll-like receptor 4 signaling. In vivo and in cultured macrophages, we identified that TG reduced the protein production of pro-inflammatory cytokines, but exhibited no significant effects on steady state levels of their transcriptions. Direct measurement on the fraction of polysome-bound mRNAs revealed that TG reduced the translational efficiency of pro-inflammatory cytokines in macrophages. Moreover, we provided evidence suggesting that repression of the mTOR (the mammalian target of rapamycin) signaling pathway, but not activation of the PERK (protein kinase R-like endoplasmic reticulum kinase)-eIF2α (eukaryotic initiation factor 2α) pathway, might be involved in mediating the TG effects on cytokine production. In summary, our results support that pharmacological preconditioning with TG may represent a novel strategy to prevent sepsis-induced mortality and organ injuries.

The rheumatology/hematology interface: CAPS and MAS diagnosis and management

Catastrophic antiphospholipid antibody syndrome (CAPS) and macrophage activation syndrome (MAS) are both life-threatening hematologic disorders that infrequently afflict patients with rheumatologic disease. CAPS is characterized by fulminant multiorgan damage related to small vessel thrombosis in the setting of persistent antiphospholipid antibodies. It can occur in patients with rheumatologic diseases such as systemic lupus erythematosus but can also affect patients who do not have rheumatologic disease. By contrast, the term MAS is applied when patients with rheumatologic disease develop hemophagocytic lymphohistiocytosis (HLH); therefore, patients with MAS have an underlying rheumatologic disease by definition. Similar to CAPS, HLH/MAS can have a fulminant presentation, but the pathogenesis and manifestations are different. In both CAPS and MAS, management generally includes but is not limited to immunosuppression with steroids. Fatalities are relatively common and morbidity is often significant. Early recognition of these disorders and initiation of timely treatment are important. More effective therapies for both syndromes are urgently needed.

Role of Damage-Associated Molecular Patterns and Uncontrolled Inflammation in Pediatric Sepsis-Induced Multiple Organ Dysfunction Syndrome

The incidence of multiple organ dysfunction syndrome (MODS) in sepsis varies from 17 to 73% and furthermore, increases the risk of death by 60% when controlled for the number of dysfunctional organs. Several MODS phenotypes exist, each unique in presentation and pathophysiology. Common to the phenotypes is the stimulation of the immune response by pathogen-associated molecular patterns (PAMPs), or danger-associated molecular patterns (DAMPs) causing an unremitting inflammation. Two of the MODS phenotypes are discussed in detail, thrombocytopenia-associated multiple organ failure (TAMOF) and the hyperinflammatory phenotype-macrophage activating syndrome (MAS) and hemophagocytic lymphohistiocytosis (HLH). In the end, we will briefly review the role of mitochondrial dysfunction as a significant contributor to the pathogenesis of MODS.

Anakinra Therapy for Non-cancer Inflammatory Diseases

Interleukin-1 (IL-1) is the prototypical inflammatory cytokine: two distinct ligands (IL-1α and IL-1β) bind the IL-1 type 1 receptor (IL-1R1) and induce a myriad of secondary inflammatory mediators, including prostaglandins, cytokines, and chemokines. IL-1α is constitutively present in endothelial and epithelial cells, whereas IL-1β is inducible in myeloid cells and released following cleavage by caspase-1. Over the past 30 years, IL-1-mediated inflammation has been established in a broad spectrum of diseases, ranging from rare autoinflammatory diseases to common conditions such as gout and rheumatoid arthritis (RA), type 2 diabetes, atherosclerosis, and acute myocardial infarction. Blocking IL-1 entered the clinical arena with anakinra, the recombinant form of the naturally occurring IL-1 receptor antagonist (IL-1Ra); IL-1Ra prevents the binding of IL-1α as well as IL-1β to IL-1R1. Quenching IL-1-mediated inflammation prevents the detrimental consequences of tissue damage and organ dysfunction. Although anakinra is presently approved for the treatment of RA and cryopyrin-associated periodic syndromes, off-label use of anakinra far exceeds its approved indications. Dosing of 100 mg of anakinra subcutaneously provides clinically evident benefits within days and for some diseases, anakinra has been used daily for over 12 years. Compared to other biologics, anakinra has an unparalleled record of safety: opportunistic infections, particularly Mycobacterium tuberculosis, are rare even in populations at risk for reactivation of latent infections. Because of this excellent safety profile and relative short duration of action, anakinra can also be used as a diagnostic tool for undefined diseases mediated by IL-1. Although anakinra is presently in clinical trials to treat cancer, this review focuses on anakinra treatment of acute as well as chronic inflammatory diseases.

Targeting cytokines to treat autoinflammatory diseases

Autoinflammatory diseases are rare group of conditions manifested by recurrent fevers, systemic inflammation, and dysfunctions of the innate immune system. These conditions are characterized by overproduction or lack of inhibition of various cytokines, and the advent of biologic drugs that block specific cytokines involved in these conditions has revolutionized their treatment. In this review, I will discuss the most common autoinflammatory conditions of adulthood including familial Mediterranean fever (FMF), cryopyrin-associated periodic syndrome (CAPS), mevalonate kinase deficiency/hyperimmunoglobulinemia D Syndrome (MKD/HIDS), TNF receptor-associated autoinflammatory syndrome (TRAPS), and systemic juvenile idiopathic arthritis/adult-onset Still's disease (SJIA/AOSD). I will discuss how IL-1, IL-6, IL-18, and TNF play pathogenic roles in these conditions and will review the evidence behind cytokine blockade for these diseases. Throughout the paper, I will reflect on gaps in knowledge of autoinflammatory diseases and will highlight the latest advances and newest drugs in development.

Two indole-2-carboxamide derivatives attenuate lipopolysaccharide-induced acute lung injury by inhibiting inflammatory response

Acute lung injury (ALI) is the leading cause of mortality in the intensive care unit. Currently, there is no effective pharmacological treatment for ALI. In our previous study, we reported that Lg25 and Lg26, two indole-2-carboxamide derivatives, inhibited the lipopolysaccharide (LPS)-induced inflammatory cytokines in vitro and attenuated LPS-induced sepsis in vivo. In the present study, we confirmed data from previous studies that LPS significantly induced pulmonary edema and pathological changes in lung tissue, increased protein concentration and number of inflammatory cells in bronchoalveolar lavage fluids (BALF), and increased inflammatory cytokine TNF-α expression in serum and BALF, pro-inflammatory genes expression, and macrophages infiltration in lung tissue. However, pretreatment with Lg25 and Lg26 significantly attenuated the LPS-induced changes in mice. Taken together, these data indicate that the newly discovered indole-2-carboxamide derivatives could be particularly useful in the treatment of inflammatory diseases such as ALI.

Hepatobiliary Dysfunction and Disseminated Intravascular Coagulation Increase Risk of Mortality in Pediatric Hemophagocytic Lymphohistiocytosis

OBJECTIVES

Hemophagocytic lymphohistiocytosis poses significant challenges due to limited tools to guide clinical decisions in a population at high risk of death. We sought to assess whether disseminated intravascular coagulation and hepatobiliary dysfunction, significant comorbidities seen in critical care settings, would identify hemophagocytic lymphohistiocytosis patients with increased risk of mortality.

DESIGN

Retrospective chart review.

SETTING

Single-center PICU.

PATIENTS

All patients admitted to a tertiary care children's hospital diagnosed with hemophagocytic lymphohistiocytosis from 2005 to 2012.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Forty-three patients were diagnosed with hemophagocytic lymphohistiocytosis with median age of 61 months. The 5-year overall survival was 51% (22/43). Univariate analyses revealed ferritin levels greater than 10,000 (ng/mL), international normalized ratio greater than 1.5, or platelet counts less than 100,000/µL at initiation of dexamethasone were individually associated with mortality. Development of disseminated intravascular coagulation, hepatobiliary dysfunction, or both increased the likelihood of death in hemophagocytic lymphohistiocytosis patients (relative risk; 95% CI) (6; 1.4-34; p < 0.05), (4.1; 1.8-10; p < 0.05), and (7.5; 1.8-42; p < 0.05). Of 12 autopsies performed, 75% had at least one active infection, 66% had chronic lymphopenia, 50% had lymphocyte depletion in the spleen, thymus, or bone marrow, 42% had evidence of microvascular thrombosis, and 92% had evidence of hepatocellular injury.

CONCLUSIONS

Hemophagocytic lymphohistiocytosis continues to have high mortality with hemophagocytic lymphohistiocytosis-1994/2004 (dexamethasone/etoposide), the current standard of care for all children with hemophagocytic lymphohistiocytosis. Hemophagocytic lymphohistiocytosis patients who developed disseminated intravascular coagulation, hepatobiliary dysfunction, or both had higher risk of death with mortalities of 60%, 77%, and 77%, respectively. Phenotypic classifications are urgently needed to guide individualized treatment strategies to improve outcomes for children with hemophagocytic lymphohistiocytosis.

Precision Immunotherapy for Sepsis

Decades of sepsis research into a specific immune system-targeting adjunctive therapy have not resulted in the discovery of an effective compound. Apart from antibiotics, source control, resuscitation and organ support, not a single adjunctive treatment is used in current clinical practice. The inability to determine the prevailing immunological phenotype of patients and the related large heterogeneity of study populations are regarded by many as the most important factors behind the disappointing results of past clinical trials. While the therapeutic focus has long been on immunosuppressive strategies, increased appreciation of the importance of sepsis-induced immunoparalysis in causing morbidity and mortality in sepsis patients has resulted in a paradigm shift in the sepsis research field towards strategies aimed at enhancing the immune response. However, similar to immunosuppressive therapies, precision medicine is imperative for future trials with immunostimulatory compounds to succeed. As such, identifying those patients with a severely suppressed or hyperactive immune system who will most likely benefit from either immunostimulatory or immunosuppressive therapy, and accurate monitoring of both the immune and treatment response is crucial. This review provides an overview of the challenges lying ahead on the path towards precision immunotherapy for patients suffering from sepsis.

Chemical disruption of the pyroptotic pore-forming protein gasdermin D inhibits inflammatory cell death and sepsis

Dysregulation of inflammatory cell death is a key driver of many inflammatory diseases. Pyroptosis, a highly inflammatory form of cell death, uses intracellularly generated pores to disrupt electrolyte homeostasis and execute cell death. Gasdermin D, the pore-forming effector protein of pyroptosis, coordinates membrane lysis and the release of highly inflammatory molecules, such as interleukin-1β, which potentiate the overactivation of the innate immune response. However, to date, there is no pharmacologic mechanism to disrupt pyroptosis. Here, we identify necrosulfonamide as a direct chemical inhibitor of gasdermin D, the pyroptotic pore-forming protein, which binds directly to gasdermin D to inhibit pyroptosis. Pharmacologic inhibition of pyroptotic cell death by necrosulfonamide is efficacious in sepsis models and suggests that gasdermin D inhibitors may be efficacious clinically in inflammatory diseases.

Inflammasomes in Tissue Damages and Immune Disorders After Trauma

Trauma remains a leading cause of death worldwide. Hemorrhagic shock and direct injury to vital organs are responsible for early mortality whereas most delayed deaths are secondary to complex pathophysiological processes. These processes result from imbalanced systemic reactions to the multiple aggressions associated with trauma. Trauma results in the uncontrolled local and systemic release of endogenous mediators acting as danger signals [damage-associated molecular patterns (DAMPs)]. Their recognition by the innate immune system triggers a pro-inflammatory immune response paradoxically associated with concomitant immunosuppression. These responses, ranging in intensity from inappropriate to overwhelming, promote the propagation of injuries to remote organs, leading to multiple organ failure and death. Some of the numerous DAMPs released after trauma trigger the assembly of intracellular multiprotein complexes named inflammasomes. Once activated by a ligand, inflammasomes lead to the activation of a caspase. Activated caspases allow the release of mature forms of interleukin-1β and interleukin-18 and trigger a specific pro-inflammatory cell death termed pyroptosis. Accumulating data suggest that inflammasomes, mainly NLRP3, NLRP1, and AIM2, are involved in the generation of tissue damage and immune dysfunction after trauma. Following trauma-induced DAMP(s) recognition, inflammasomes participate in multiple ways in the development of exaggerated systemic and organ-specific inflammatory response, contributing to organ damage. Inflammasomes are involved in the innate responses to traumatic brain injury and contribute to the development of acute respiratory distress syndrome. Inflammasomes may also play a role in post-trauma immunosuppression mediated by dysregulated monocyte functions. Characterizing the involvement of inflammasomes in the pathogenesis of post-trauma syndrome is a key issue as they may be potential therapeutic targets. This review summarizes the current knowledge on the roles of inflammasomes in trauma.

Interleukin-1 receptor antagonist as a biomarker of sepsis in neutropenic haematological patients

OBJECTIVE

The study aim was to compare the performance of interleukin-1 receptor antagonist (IL-1Ra) to C-reactive protein (CRP) and procalcitonin (PCT) in early prediction of the clinical course of febrile neutropenia.

METHODS

The study population consisted of 86 consecutive patients with febrile neutropenia who received intensive chemotherapy for haematological malignancy between November 2009 and November 2012 at the adult haematology ward of Kuopio University Hospital. Twenty-three (27%) patients had acute myeloid leukaemia and 63 (73%) patients were autologous stem cell transplant recipients. IL-1Ra, CRP and procalcitonin were measured at the onset of fever (d0), on day 1 (d1) and on day 2 (d2).

RESULTS

Eight patients developed severe sepsis, including three patients with septic shock. Eighteen patients had bacteraemia. After the onset of febrile neutropenia Youden´s indices (with their 95% confidence intervals) to identify severe sepsis were for IL-1Ra on d0 0.57 (0.20-0.71) and on d1 0.65 (0.28-0.78), for CRP on d0 0.41 (0.04-0.61) and on d1 0.47 (0.11-0.67) and for PCT on d0 0.39 (0.05-0.66) and on d1 0.52 (0.18-0.76).

CONCLUSIONS

In haematological patients, IL-1Ra has a comparable capacity with CRP and PCT to predict severe sepsis at the early stages of febrile neutropenia.

Sphingosine-1-phosphate Receptor 2 Signaling Promotes Caspase-11–dependent Macrophage Pyroptosis and Worsens Escherichia coli Sepsis Outcome

What We Already Know about This Topic

What This Article Tells Us That Is New

Background

Pyroptosis, a type of proinflammatory programmed cell death, drives cytokine storm. Caspase-11–dependent macrophage pyroptosis contributes to mortality during sepsis. Sphingosine-1-phosphate receptor 2 (S1PR2) signaling can amplify interleukin-1β secretion in endotoxin-induced inflammation. Here, we hypothesized that S1PR2 signaling increases caspase-11–dependent macrophage pyroptosis and worsens Gram-negative sepsis outcome.

Methods

A Gram-negative sepsis model was induced through intraperitoneal injection of Escherichia coli. Primary peritoneal macrophages isolated from wild-type, S1pr2-deficient (S1pr2-/-), or nucleotide-binding oligomerization domain-like receptor protein-3–deficient mice were treated with E. coli. Caspase-11 activation, macrophage pyroptosis, and Ras homolog gene family, member A-guanosine triphosphate levels were assessed in those cells. Additionally, monocyte caspase-4 (an analog of caspase-11) expression and its correlation with S1PR2 expression were determined in patients with Gram-negative sepsis (n = 11).

Results

Genetic deficiency of S1PR2 significantly improved survival rate (2/10 [20%] in wild-type vs. 7/10 [70%] in S1pr2-/-, P = 0.004) and decreased peritoneal macrophage pyroptosis (pyroptosis rate: 35 ± 3% in wild-type vs. 10 ± 3% in S1pr2-/-, P &lt; 0.001). Decreased caspase-11 activation in S1PR2 deficiency cells contributed to the reduced macrophage pyroptosis. In addition, RhoA inhibitor abrogated the amplified caspase-11 activation in wild-type or S1PR2-overexpressing cells. In patients with Gram-negative sepsis, caspase-4 increased significantly in monocytes compared to nonseptic controls and was positively correlated with S1PR2 (r = 0.636, P = 0.035).

Conclusions

S1PR2 deficiency decreased macrophage pyroptosis and improved survival in E. coli sepsis. These beneficial effects were attributed to the decreased caspase-11 activation of S1PR2-deficient macrophages. S1PR2 and caspase-11 may be promising new targets for treatment of sepsis.

Systemic Juvenile Idiopathic Arthritis

Systemic juvenile idiopathic arthritis (sJIA) is a distinctive subtype of juvenile idiopathic arthritis, characterized by fever and arthritis, often accompanied by rash, sometimes by generalized lymphadenopathy, hepatosplenomegaly, and serositis. The diagnosis requires adequate exclusion of infectious, oncologic, autoimmune, and autoinflammatory diseases. Macrophage activation syndrome, a serious and potentially fatal complication of sJIA, requires prompt evaluation and treatment. Newer biologic agents, particularly interleukin-1 and interleukin-6 inhibitors, are highly effective and have transformed the treatment approach by reducing the use of systemic glucocorticoids. Primary care providers have a crucial role in monitoring children with sJIA for disease-related complications and medication-related adverse events.

Secondary Hemophagocytic Lymphohistiocytosis, Macrophage Activation Syndrome, and Hyperferritinemic Sepsis-Induced Multiple-Organ Dysfunction Syndrome in the Pediatric ICU

Children with secondary hemophagocytic lymphohistiocytosis present diagnostic and therapeutic challenges to the intensivist. Management of this condition can be facilitated with a collaborative approach among a team of intensivists, immunologists, rheumatologists, hematologists, and infectious disease specialists. Controversy over management approach commonly centers on incomplete understanding at the time of clinical presentation regarding individual patient differences in inflammation pathobiology that require different therapies. This review provides the clinician with the rationale for personalizing care for these critically ill children.