Coagulation Disorders and Bleedings in Critically Ill Patients With Hemophagocytic Lymphohistiocytosis

Secondary hemophagocytic lymphohistiocytosis in pediatric patients with visceral leishmaniasis and Epstein-Barr virus infection

Visceral leishmaniasis-associated hemophagocytic lymphohistiocytosis (VL-HLH) is indistinguishable from those of HLH of other etiologies due to the overlap symptoms, posing a serious threat to life. In this study, we aimed to provide insights for early diagnosis and improve outcomes in pediatric patients with VL-HLH. We retrospectively analyzed the clinical and laboratory data of 10 pediatric patients with VL-HLH and 58 pediatric patients with Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis (EBV-HLH). The median time from symptom onset to cytopenia in patients with VL-HLH and EBV-HLH was 11 days (interquartile range, 7-15 days) and five days (interquartile range, 3.75-9.25 days) (P = 0.005). Both groups showed liver injury and increased lactate dehydrogenase levels; however the levels of aspartate aminotransferase, alanine aminotransferase, direct bilirubin, and lactate dehydrogenase in patients with VL-HLH were significantly lower than those in patients with EBV-HLH (P < 0.05). The fibrinogen and triglyceride levels were almost normal in VL-HLH patients but were significantly altered in EBV-HLH cases ( P < 0.05). The positive rate of first bone marrow microscopy examination, anti-rK39 IgG detection, and blood metagenomic next-generation sequencing was 50%, 100%, and 100%, respectively. After VL diagnosis, eight patients were treated with sodium stibogluconate and two were treated with liposomal amphotericin B. All the patients with VL-HLH recovered. Our study demonstrates that regular triglyceride and fibrinogen levels in pediatric patients with VL-HLH may help in differential diagnosis from EBV-HLH. VL-HLH is milder than EBV-HLH, with less severe liver injury and inflammatory responses, and timely treatment with antileishmanial agents is essential to improve the outcomes of pediatric patients with VL-HLH.

Patients with Hemophagocytic Lymphohistiocytosis Who Need Intensive Care Can Be Successfully Rescued by Timely Using Etoposide-Based HLH Regimens

Background

Hemophagocytic lymphohistiocytosis (HLH) patients who need intensive care usually have multiple organ failure and poor prognosis. However, the clinical characteristics, therapeutic efficacy and outcome in these critically ill HLH patients have remained unclear.

Methods

We performed a retrospective study of 50 critically ill HLH patients from September 2013 to October 2022. Patients' information was collected, and the overall survival rate was estimated.

Results

Fifty HLH patients need intensive care, and the median sequential organ failure assessment (SOFA) score was 8. 66.00% patients had septic shock, 60.00% had disseminated intravascular coagulation (DIC) and 56.00% had acute respiratory distress syndrome (ARDS). 64.00% patients needed vasoactive drugs, 60.00% needed invasive or non-invasive positive pressure mechanical ventilation, and 12.00% needed continuous renal replacement therapy (CRRT). Among 18 patients received the etoposide-based regimens, the median time for 17 patients to remove ECG monitoring was 13 days (4-30 days); the median time to remove respiratory support in 10 patients was 8.5 days (4-21 days); the median time for 5 patient to convert from dominant DIC to non-dominant DIC was 4 days (1-14 days) and the median time for 6 patients to stop using vasoactive drugs was 10 days (2-14 days). After 4 weeks of treatment, 7 patients were evaluated as NR, 6 achieved PR, and 5 could not be evaluated. The ORR was 55.56%. Up to the last follow-up, the OS rate of patients receiving etoposide-based regimens was 66.67%. In contrast, all 32 HLH patients in other groups died. Univariate analysis showed that PCT > 0.5 ug/L, PT prolonged > 6 s, TBil > 25umol/L, respiratory failure, renal failure, liver failure and did not receive etoposide- based regimens were the negative factors affecting survival (P = 0.001, 0.017, 0.043, 0.001, 0.000, 0.029, 0.000).

Conclusion

HLH patients who need intensive care timely used etoposide-based HLH regimens might rescue critically ill patients successfully.

CD8+ T-cells target the Crimean-Congo haemorrhagic fever virus Gc protein to control the infection in wild-type mice

BACKGROUND

Crimean-Congo haemorrhagic fever (CCHF) is a serious viral hemorrhagic fever caused by the CCHF virus (CCHFV). Spread by the bites of infected ticks or handling of viremic livestock, human disease is characterized by a non-specific febrile illness that can rapidly progress to fatal hemorrhagic disease. No vaccines or antivirals are available. Case fatality rates can vary but can be higher than 30%, although sub-clinical infections are often unrecognized and unreported. Yet, while most humans infected with CCHFV will survive the infection, often with little-to-no symptoms, the host responses that control the infection are unknown.

METHODS

Here we investigated the role of cellular immunity in control of CCHFV infection in an immunocompetent mouse model.

FINDINGS

We found that CD8+ T-cells are crucial for efficient control of the acute infection and rapidly acquired CCHFV-specific antiviral effector functions such as production of antiviral cytokines and degranulating in response to CCHFV peptides. We further identified the minimal CD8+ T-cell epitopes in the viral Gc proteins and that infection of mice lacking IFNγ resulted in worsened disease and higher viral loads.

INTERPRETATION

Together our data suggest that CD8+ T-cells are important for control of acute CCHFV infection likely through production of antiviral cytokines.

FUNDING

This work was supported by the Intramural Research Program of the NIH.

A novel prognosis-prediction model based on coagulation indicators in secondary hemophagocytic lymphohistiocytosis

Secondary hemophagocytic lymphohistiocytosis (HLH) is a life-threatening disease. In the present retrospective study, we aimed to investigate coagulation disorders and their outcome implications in patients with secondary HLH. We evaluated clinical characteristics and the relationship between coagulation indices and prognosis in HLH patients (n = 141). The information, including clinical symptoms, laboratory indicators, and coagulation indices, was evaluated. Coagulation disorders and bleeding events occurred in 95 (67.4%) and 60 (42.6%) patients, respectively. A coagulation index analysis primarily showed elevated levels of D-Dimer, the international standardized ratio (INR), prothrombin time (PT), activated partial thromboplastin time (APTT), and thrombin time (TT), while the prothrombin activity, fibrinogen levels, and platelet levels were significantly decreased. Dominant disseminated intravascular coagulation (DIC) occurred in 76 patients (53.9%). Patients with lymphoma-associated hemophagocytic syndrome (LAHS) frequently exhibited apparent coagulation disorders. Multivariate analysis revealed that age ≥ 29.5 years, bleeding events, APTT ≥ 47.3 s, fibrinogen ≤ 1.68 g/L, and absolute neutrophil counts (ANC) of ≤ 1.21 × 109/L were independent prognostic factors. We thereby devised a prognostic scoring system and stratified patients into low-risk (0-2 points), intermediate-risk (3-4 points), and high-risk (5-7 points) groups, and the 1-year overall survival rates in the above-mentioned groups were 66.40%, 40.00%, and 2.30%, respectively (P < 0.0001). In conclusion, coagulation dysfunctions and bleeding tendencies were common characteristics in HLH patients. We constructed a novel prognostic score model based on APTT, fibrinogen level, ANC, age, and bleeding events, which had superior prognostic value compared with these markers alone.

Ocular Phenotypes in Patients With Hemophagocytic Lymphohistiocytosis: A Retrospective Analysis in a Single Center Over 7 Years

PURPOSE

To investigate the presence and type of ocular abnormalities in patients with hemophagocytic lymphohistiocytosis (HLH).

DESIGN

A retrospective cross-sectional study.

METHODS

Observational report of ocular findings and their associations with age, sex, underlying disease, and hematologic parameters. HLH was defined according to the 2004 criteria, and the patients were enrolled from March 2013 to December 2021. Analysis began in July 2022 and ended in January 2023. The main outcome measures were ocular abnormalities associated with HLH and their potential risk factors.

RESULTS

Of 1525 HLH patients, 341 had ocular examinations, and 133 (133 of 341, 39.00%) had ocular abnormalities. Mean age at presentation was 30.21 ± 14.42 years. The multivariate analysis indicated that old age, autoimmune disorders, decreasing red blood cell count, decreasing platelet count, and increasing fibrinogen level were independent risk factors of ocular involvement in HLH patients. The most common presenting ocular findings were posterior segment abnormalities (66 patients, 49.62%), including retinal and vitreous hemorrhage, serous retinal detachment, cytomegalovirus retinitis, and optic disc swelling. Other HLH-associated ocular abnormalities included ocular surface infection (conjunctivitis, 34 patients, 25.56%; keratitis, 16 patients, 12.03%), subconjunctival hemorrhage (11 patients, 8.27%), chemosis (5 patients, 3.76%), anterior uveitis (11 patients, 8.27%), glucocorticoid-induced glaucoma (5 patients, 3.76%), radiation cataract (1 patient, 0.75%), dacryoadenitis (2 patients, 1.50%), dacryocystitis (1 patients, 0.75%), orbital cellulitis (2 patients, 1.50%), orbital pseudotumor (2 patients, 1.50%), and strabismus (2 patients, 1.50%).

CONCLUSIONS

Eye involvement is not uncommon in HLH. Better awareness among both ophthalmologists and hematologists is necessary for prompt diagnosis and institution of appropriate management strategies with potential to save sight and life.

Research priorities for therapeutic plasma exchange in critically ill patients

Therapeutic plasma exchange (TPE) is a therapeutic intervention that separates plasma from blood cells to remove pathological factors or to replenish deficient factors. The use of TPE is increasing over the last decades. However, despite a good theoretical rationale and biological plausibility for TPE as a therapy for numerous diseases or syndromes associated with critical illness, TPE in the intensive care unit (ICU) setting has not been studied extensively. A group of eighteen experts around the globe from different clinical backgrounds used a modified Delphi method to phrase key research questions related to "TPE in the critically ill patient". These questions focused on: (1) the pathophysiological role of the removal and replacement process, (2) optimal timing of treatment, (3) dosing and treatment regimes, (4) risk-benefit assumptions and (5) novel indications in need of exploration. For all five topics, the current understanding as well as gaps in knowledge and future directions were assessed. The content should stimulate future research in the field and novel clinical applications.

Biomarker diversity in increased inflammation: Secondary hemophagocytic syndrome vs. systemic inflammatory response syndrome

INTRODUCTION

Secondary hemophagocytic syndrome (HPS) and systemic inflammatory response syndrome (SIRS) share similar clinical findings as a result of hyperinflammation. Due to high mortality rates in HPS; it is critical to diagnose promptly. Thus, this study aimed to evaluate the diagnostic and prognostic significance of inflammatory markers in these two increased inflammatory states.

METHODS

We conducted a prospective observational study including patients hospitalized in the intensive care unit of the Internal Medicine Department of Ege University Hospital.

RESULTS

Thirty-three patients with HPS and 46 patients with SIRS were evaluated. Serum ferritin and sIL-2r levels were significantly higher in the HPS group than in the SIRS group, as expected. Receiver operating curve (ROC) analysis showed that the optimal cutoff for ferritin to distinguish HPS from SIRS was 1703 μg/L (sensitivity: 75%, specificity: 94.1%, area under the curve (AUC): 0.871, p < 0.001), and that for sIL-2r was 5888 U/ml (sensitivity: 45.5%, specificity: 89.1%, AUC: 0.698, and p = 0.001). Temporal changes (Δ) in ferritin were determined as a mortality predictor. When evaluated in terms of prognostic significance in ROC analysis, a decrease in ferritin of less than 38% was the cutoff value (sensitivity: 92.3%, specificity: 76.9%, AUC: 0.888, and p < 0.001), in mortality. Contrarily, neither baseline nor temporal change in sIL-2r did not achieve prognostic significance as a mortality predictor.

CONCLUSION

In this single-center study, serum ferritin level was found to be a particularly more valuable diagnostic and prognostic marker than sIL-2r in patients with HPS.

Coagulopathy is an under-recognised complication of acquired HLH

Acquired haemophagocytic lymphohistiocytosis (aHLH) is a rare and often fatal process of uncontrolled cytokine release driven by the inability of natural killer cells to eliminate infected or malignant cells. Herein, we report two cases of aHLH complicated by bleeding secondary to coagulopathy due to hypofibrinogenaemia and thrombocytopenia despite appropriate correction with blood products. These cases highlight the effect coagulopathy and thrombocytopenia can have on patient outcomes when trying to confirm and manage the underlying process driving aHLH.

Presentations and outcomes of familial hemophagocytic lymphohistiocytosis in the pediatric intensive care units (PICUs)

Objectives

We aimed to describe Familial Hemophagocytic Lymphohistiocytosis (F-HLH) patients' clinical features, intensive care courses, and outcomes.

Methods

Multi-center retrospective cohort study of pediatric patients diagnosed with F-HLH from 2015 to 2020 in five tertiary centers in Saudi Arabia. Patients were classified as F-HLH based on their genetic confirmation of known mutation or on their clinical criteria, which include a constellation of abnormalities, early disease onset, recurrent HLH in the absence of other causes, or a family history of HLH.

Results

Fifty-eight patients (28 male, 30 female), with a mean age of 21.0 ± 33.9 months, were included. The most common principal diagnosis was hematological or immune dysfunction (39.7%), followed by cardiovascular dysfunction in 13 (22.4%) patients. Fever was the most common clinical presentation in 27.6%, followed by convulsions (13.8%) and bleeding (13.8%). There were 20 patients (34.5%) who had splenomegaly, and more than 70% of patients had hyperferritinemia >500 mg/dl, hypertriglyceridemia >150 mg/dl and hemophagocytosis in bone marrow biopsy. Compared to deceased patients 18 (31%), survivors had significantly lower PT (p = 041), bilirubin level of <34.2 mmol/L (p = 0.042), higher serum triglyceride level (p = 0.036), and lesser bleeding within the initial 6 h of admission (p = 0.004). Risk factors for mortality included requirements of higher levels of hemodynamic (61.1% vs. 17.5%, p = 0.001) and respiratory (88.9% vs. 37.5%, p < 0.001) support, and positive fungal cultures (p = 0.046).

Conclusions

Familial HLH still represents a challenge in the pediatric critical care setting. Earlier diagnosis and prompt initiation of appropriate treatment could improve F-HLH survival.

Etoposide treatment in secondary hemophagocytic syndrome: impact on healthcare-associated infections and survival

Background

Etoposide remains the cornerstone of symptomatic management of critically ill patients with secondary hemophagocytic syndrome (sHS). Risk of healthcare-associated infections (HAIs) in this setting with etoposide has never been assessed. We sought to evaluate the association between etoposide administration, HAIs occurrence and survival in critically ill adult patients with sHS. In this retrospective single-center study conducted in a university hospital ICU between January 2007 and March 2020, all consecutive patients with sHS were included. HAIs were defined as any microbiologically documented infection throughout ICU stay. Competing risk survival analysis was performed to determine factors associated with HAIs. Propensity score-based overlap weighting was performed to adjust for factors associated with etoposide use.

Results

168 patients with a median age of 49 [38, 59] were included. Forty-three (25.6%) patients presented with at least 1 microbiologically documented HAI throughout ICU stay. After adjustment, cumulative incidence of HAI was higher in patients receiving etoposide (p = 0.007), while survival was unaffected by etoposide status (p = 0.824). By multivariable analysis, etoposide treatment was associated with a higher incidence of HAIs (sHR 3.75 [1.05, 6.67]), whereas no association with survival (sHR 0.53 [0.20, 1.98]) was found. Other factors associated with increased mortality after adjustment included age, immunodepression, male sex, SOFA score > 13, and occurrence of HAI.

Conclusions

In patients with sHS, etoposide treatment is independently associated with increased occurrence of HAIs, whereas no association with survival was found. Intensivists should be aware of increased infectious risk, to promptly detect and treat infections in this specific setting. Studies to assess benefits from prophylactic anti-infectious agents in this setting are warranted and the lack of benefit of etoposide on survival needs to be interpreted cautiously.

The mechanistic basis linking cytokine storm to thrombosis in COVID-19

It is now well established that infection with SARS-CoV-2 resulting in COVID-19 disease includes a severely symptomatic subset of patients in whom an aggressive and/or dysregulated host immune response leads to cytokine storm syndrome (CSS) that may be further complicated by thrombotic events, contributing to the severe morbidity and mortality observed in COVID-19. This review provides a brief overview of cytokine storm in COVID-19, and then presents a mechanistic discussion of how cytokine storm affects integrated pathways in thrombosis involving the endothelium, platelets, the coagulation cascade, eicosanoids, auto-antibody mediated thrombosis, and the fibrinolytic system.

Hemophagocytic lymphohistiocytosis diagnosed by bone marrow trephine biopsy in living post-COVID-19 patients: case report and mini-review

Hemophagocytic lymphohistiocytosis (HLH) constitutes a life-threatening inflammatory syndrome. Postmortem histological findings of bone marrow (BM) from COVID-19 patients showed histiocytosis and hemophagocytosis and supported the hypothesis that secondary HLH (sHLH) may be triggered by SARS-CoV-2 infection. However, there are a limited number of sHLH cases in which trephine has been performed in living post-COVID-19 patients. Here we present a recent case and a mini-review of sHLH diagnosed by trephine biopsy in living patients after COVID-19. An 81-year-old man with a past medical history of hypertension, diabetes, ischemic stroke, was referred to the hospital to evaluate leukocytosis, pyuria, and elevation of inflammatory markers four weeks after recovering from COVID-19. Computed tomography of the abdomen did not reveal focal signs of infection or hepatosplenomegaly. The patient received intravenous meropenem and two packed red blood cell units. Leukocytes and C-reactive protein were gradually decreased. A BM biopsy was performed and the patient was discharged on cefixime. BM smear revealed severe anemia, lymphopenia, and dysplastic morphologic findings of erythroblasts, neutrophils, and megakaryocytes. Trephine biopsy revealed hypercellular marrow dyserythropoiesis, plasmacytosis, lymphocytosis, histiocytosis, hemophagocytosis, and the absence of granulomas or carcinoma. Immunohistochemistry documented a mixed population of T lymphocytes (CD3+) and B lymphocytes (CD20+). Strong positivity for CD68 confirmed histiocytosis. CD138 κ, λ staining proved polyclonal plasmacytosis. Perl’s staining showed excess hemosiderin deposits. Based on our findings, we document sHLH in trephine BM biopsy of a living post-COVID-19 patient and persistent leukocytosis, underscoring the diagnostic value of trephine biopsy in preventing life-threatening conditions such as COVID-19.

Incidence of bleeding and thromboembolism and impact on overall survival in adult patients with hemophagocytic lymphohistiocytosis: A 20-year provincial retrospective cohort study

BACKGROUND

Hemophagocytic lymphohistiocytosis (HLH) is a rare syndrome characterized by uncontrolled immune activation and high risk of death. There is scarce data on the incidence of bleeding and thromboembolism in HLH.

OBJECTIVES

To determine the cumulative incidence of bleeding and thromboembolism and impact on survival in adults with HLH.

PATIENTS/METHODS

We conducted a multicenter retrospective cohort study of adults with HLH in Alberta, Canada (1999-2019). The cumulative incidence of bleeding and thromboembolism were calculated, accounting for competing risks. Cox proportional hazards models were used to assess the impact of bleeding and thromboembolism on overall survival (OS).

RESULTS

We identified 97 adults with HLH (median age 46 years). Venous thromboembolism (VTE) occurred in 11 (11%) patients at a median of 9 days from admission. ISTH major bleeding and clinically relevant non-major bleeding occurred in 39 (40%) patients, at a median of 16 days after admission. Nadir platelet count (adjusted odds ratio [aOR] 1.8 per log decrease, 95% confidence interval [CI] 1.2-2.8) and mechanical ventilation (aOR 4.9, 95% CI 1.8-14.8) were independent predictors of bleeding on multivariable analysis. Adjusting for competing risks, the 90-day cumulative incidences of bleeding and thromboembolism were 39% and 13%, respectively. The median OS was 18.8 months. VTE, but not bleeding, was significantly associated with adverse OS (adjusted hazard ratio 2.5, 95% CI 1.1-5.7).

CONCLUSIONS

In adults with HLH, VTE appears more common than previously described and is a predictor of mortality, although this may be due to unadjusted confounding. VTE prevention and treatment are challenging due to high bleeding rates.

Malignancy-associated haemophagocytic lymphohistiocytosis

Haemophagocytic lymphohistiocytosis (HLH) is an inflammatory syndrome that can occur with cancer (malignancy-associated HLH) or with immune-activating therapies for cancer. Patients with lymphoma appear to be at particularly high risk for malignancy-associated HLH. The familial form of HLH is characterised by uncontrolled activation of macrophages and cytotoxic T cells, which can be identified by genetics or specific immune markers. However, the pathophysiology of malignancy-associated HLH is not well understood, and distinguishing pathological immune activation from the laboratory and clinical abnormalities seen in cancer and cancer treatment is challenging. Emerging diagnostic tools, such as serum cytokine or chemokine concentrations, flow cytometry, and other functional measures, are discussed. Mortality remains high with current approaches. Targeted therapy, including blockade of specific cytokines such as IL-1, IL-6, and IFNγ, and inhibition of the JAK-STAT pathways might improve outcomes for some patients. Finally, we discuss a framework for thinking of malignancy-associated HLH within a larger umbrella concept of cytokine storm syndrome.

Hemophagocytic Lymphohistiocytosis and Infection: A Literature Review

Hemophagocytic lymphocytosis (HLH) is a life-threatening, underdiagnosed syndrome caused by the excessive release of inflammatory mediators. Primary lymphocytosis is usually seen in young children and is associated with genetic defects, while secondary lymphocytosis is presented in adults due to malignancy, rheumatic disease, or infection. The aim of this study is to describe the infectious agents that trigger HLH in the adult population and provide diagnostic and treatment guidelines for this life-threatening syndrome. We conducted a literature review using PubMed as our basic database. We collected papers from the past six years that studied infectious agents that triggered HLH and described the most recommended treatment options for this serious condition. A total of 32 studies were included for this literature review.HLH is considered a syndrome with variable symptoms, and clinicians should be familiar with its complexity and the pathologies that could contribute to its presentation. Collaboration between physicians and awareness are basic steps for the management of patients with HLH.

Monitoring coagulation-fibrinolysis activation prompted timely diagnosis of hemophagocytic lymphohistiocytosis-related disseminated intravascular coagulation

Background

Timely diagnosis of disseminated intravascular coagulation (DIC) in hemophagocytic lymphohistiocytosis (HLH) patients is crucial but challenging, as HLH interferes with the results of the laboratory tests included in the DIC score system.

Case presentation

Here, we reported a case of lymphoma-associated HLH, in which coagulation-fibrinolysis activation /inhibition markers (TAT, tPAIC, and PIC), prompted timely diagnosis of early stage DIC (initial phase of microvascular thrombosis, yet non-overt), prior to the development of organ failures and/or bleedings.

Conclusions

This report highlights the importance of the implementation of new biomarkers (such as TAT, tPAIC, and PIC), into the diagnostic work-up for coagulation disorders. These biomarkers are directly suggestive of microthrombus formation, therefore they can be of paramount importance in diagnosing DIC with complicated etiologies, such as hematological diseases-related DIC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12959-021-00338-y.

High Mortality of HLH in ICU Regardless Etiology or Treatment

Background: Adult hemophagocytic lymphohistiocytosis (HLH) is highly lethal in the ICU. The diagnostic and therapeutic emergency that HLH represents is compounded by its unknown pathophysiological mechanisms. Here, we report on a large cohort of adult HLH in the ICU (ICU-HLH). We analyzed prognostic factors associated with mortality to define the diagnostic and therapeutic challenges in this specific population. Methods: This retrospective study included adult patients diagnosed with HLH in four ICUs in Marseille, France between 2010 and 2020. Patients who fulfilled the HLH-2004 criteria (≥ 4/8) and/or had an HScore ≥ 169 were diagnosed with HLH. HLH was categorized into four groups according to etiology: sepsis-associated HLH, intracellular infection-associated HLH, malignancy-associated HLH, and idiopathic HLH. Results: Two hundred and sixty patients were included: 121 sepsis-associated HLH (47%), 84 intracellular infection-associated HLH (32%), 28 malignancy-associated HLH (11%), and 27 idiopathic HLH (10%). The ICU mortality rate reached 57% (n = 147/260) without a statistical difference between etiological groups. Independent factors associated with mortality in multivariate analysis included age (OR (5 years) = 1.31 [1.16-1.48], p < 0.0001), SOFA score at ICU admission (OR = 1.37 [1.21-1.56], p < 0.0001), degradation of the SOFA score between ICU arrival and HLH diagnosis (Delta SOFA) (OR = 1.47 [1.28-1.70], p < 0.0001), the presence of bone-marrow hemophagocytosis (OR = 5.27 [1.11-24.97], p = 0.04), highly severe anemia (OR = 1.44 [1.09-1.91], p = 0.01), and hypofibrinogenemia (OR = 1.21 [1.04-1.41], p = 0.02). Conclusions: In this large retrospective cohort study of critically ill patients, ICU-HLH in adults was associated with a 57% mortality rate, regardless of HLH etiology or specific treatment. Factors independently associated with prognosis included age, presence of hemophagocytosis in bone-marrow aspirates, organ failure at admission, and worsening organ failure during the ICU stay. Whether a rapid diagnosis and the efficacy of specific therapy improve outcome is yet to be prospectively investigated.

Consensus-Based Guidelines for the Recognition, Diagnosis, and Management of Hemophagocytic Lymphohistiocytosis in Critically Ill Children and Adults

OBJECTIVE

Hemophagocytic lymphohistiocytosis is a hyperinflammatory syndrome that often requires critical care support and remains difficult to diagnose. These guidelines are meant to aid in the early recognition, diagnosis, supportive care, and treatment of patients with hemophagocytic lymphohistiocytosis in ICUs.

DATA SOURCES

The literature searches were performed with PubMed (MEDLINE).

STUDY SELECTION

Keywords and medical subject headings terms for literature search included "macrophage activation syndrome," hemophagocytic lymphohistiocytosis," and "hemophagocytic syndrome."

DATA EXTRACTION

The Histiocyte Society developed these consensus recommendations on the basis of published reports and expert opinions with level of evidence provided for each recommendation. They were endorsed by the Society of Critical Care Medicine.

DATA SYNTHESIS

Testing for hemophagocytic lymphohistiocytosis should be initiated promptly in all patients admitted to ICUs with an unexplained or disproportionate inflammatory response, especially those with rapid clinical deterioration. Meeting five or more of eight hemophagocytic lymphohistiocytosis 2004 diagnostic criteria serves as a valuable diagnostic tool for hemophagocytic lymphohistiocytosis. Early aggressive critical care interventions are often required to manage the multisystem organ failure associated with hemophagocytic lymphohistiocytosis. Thorough investigation of the underlying triggers of hemophagocytic lymphohistiocytosis, including infections, malignancies, and autoimmune/autoinflammatory diseases, is essential. Early steroid treatment is indicated for patients with familial hemophagocytic lymphohistiocytosis and is often valuable in patients with acquired hemophagocytic lymphohistiocytosis (i.e., secondary hemophagocytic lymphohistiocytosis) without previous therapy, including macrophage activation syndrome (hemophagocytic lymphohistiocytosis secondary to autoimmune/autoinflammatory disease) without persistent or relapsing disease. Steroid treatment should not be delayed, particularly if organ dysfunction is present. In patients with macrophage activation syndrome, whose disease does not sufficiently respond, interleukin-1 inhibition and/or cyclosporine A is recommended. In familial hemophagocytic lymphohistiocytosis and severe, persistent, or relapsing secondary macrophage activation syndrome, the addition of prompt individualized, age-adjusted etoposide treatment is recommended.

CONCLUSIONS

Further studies are needed to determine optimal treatment for patients with hemophagocytic lymphohistiocytosis in ICUs, including the use of novel and adjunct therapies.

Coagulation disorders in patients with severe hemophagocytic lymphohistiocytosis

Background

Coagulation disorders are common in patients with hemophagocytic lymphohistiocytosis (HLH), associated with an increased risk of bleeding and death. We aim to investigate coagulation disorders and their outcome implications in critically ill patients with HLH.

Methods

We prospectively evaluated 47 critically ill patients with HLH (median age of 54 years [42–67]) between April 2015 and December 2018. Coagulation assessments were performed at day 1. Abnormal standard coagulation was defined as prothrombin time (PT) <50% and/or fibrinogen <2g/L. HLH aetiology was mostly ascribed to haematological malignancies (74% of patients).

Results

Coagulation disorders and severe bleeding events were frequent, occurring in 30 (64%) and 11 (23%) patients respectively. At day 1, median fibrinogen level was 2∙65g/L [1.61–5.66]. Fibrinolytic activity was high as suggested by increased median levels of D-dimers, fibrin monomers, PAI-1 (plasminogen activator inhibitor) and tPA (tissue plasminogen activator). Forty-one (91%) patients had a decreased ADAMTS13 activity (A Disintegrin-like And Metalloproteinase with ThromboSpondin type 1 repeats, member 13). By multivariable analysis, the occurrence of a severe bleeding (OR 3.215 [1.194–8.653], p = 0∙021) and SOFA score (Sepsis-Related Organ Failure Assessment) at day 1 (OR 1.305 per point [1.146–1.485], p<0∙001) were independently associated with hospital mortality. No early biological marker was associated with severe bleeding.

Conclusions

Hyperfibrinolysis may be the primary mechanism responsible for hypofibrinogenemia and may also participate in ADAMTS13 degradation. Targeting the plasmin system appears as a promising approach in severe HLH-related coagulation disorders.

Treatment and Mortality of Hemophagocytic Lymphohistiocytosis in Adult Critically Ill Patients: A Systematic Review With Pooled Analysis

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.

Practical guidelines for monitoring and management of coagulopathy following tisagenlecleucel CAR T-cell therapy

Cytokine release syndrome (CRS) is a systemic inflammatory response associated with chimeric antigen receptor T-cell (CAR-T) therapies. In severe cases, CRS can be associated with coagulopathy and hypofibrinogenemia. We present our global multicenter experience with CRS-associated coagulopathy after tisagenlecleucel therapy in 137 patients with relapsed or refractory B-cell acute lymphoblastic leukemia from the ELIANA and ENSIGN trials. These trials included clinical guidelines for fibrinogen replacement during CRS-associated coagulopathy. Hypofibrinogenemia requiring replacement was observed only in patients with severe CRS. A higher percentage of patients who required replacement were <10 years old, compared with those who did not require replacement. Twenty-three patients received replacement for hypofibrinogenemia (<1.5 g/L); 9 of them developed marked hypofibrinogenemia (<1 g/L). Very low fibrinogen levels (<1 g/L) were documented in patients before maximal CRS (n = 1), during maximal CRS (n = 7), and at CRS improvement (n = 1). Although hypofibrinogenemia was the most clinically significant coagulopathy, some patients also developed prolonged prothrombin time and activated partial thromboplastin time and increased international normalized ratio, further increasing the risk of bleeding. Hypofibrinogenemia was effectively managed using fibrinogen concentrate or cryoprecipitate replacement; severe (grade 4) bleeding events were rare (n = 2). CRS-associated coagulopathy with hypofibrinogenemia is manageable according to empiric guidelines of fibrinogen replacement for CAR-T trials. Fibrinogen concentrate should be used when cryoprecipitate is not reliably available. Monitoring fibrinogen levels in patients with moderate or severe CRS is essential for avoiding potentially fatal bleeding events. These trials were registered at www.clinicaltrials.gov as #NCT02435849 and #NCT02228096.

Plasma Ferritin as Marker of Macrophage Activation-Like Syndrome in Critically Ill Patients With Community-Acquired Pneumonia

OBJECTIVES

Plasma ferritin levels above 4,420 ng/mL have been proposed as a diagnostic marker for macrophage activation-like syndrome in sepsis and used for selection of sepsis patients for anti-inflammatory therapy. We here sought to determine the frequency, presentation, outcome, and host response aberrations of macrophage activation-like syndrome, as defined by admission ferritin levels above 4,420 ng/mL, in critically ill patients with community-acquired pneumonia.

DESIGN

A prospective observational cohort study.

SETTING

ICUs in two tertiary hospitals in the Netherlands.

PATIENTS

One hundred fifty-three patients admitted with community-acquired pneumonia.

MEASUREMENTS AND MAIN RESULTS

Patients were stratified in community-acquired pneumonia-macrophage activation-like syndrome (n = 15; 9.8%) and community-acquired pneumonia-control groups (n = 138; 90.2%) based on an admission plasma ferritin level above or below 4,420 ng/mL, respectively. Community-acquired pneumonia-macrophage activation-like syndrome patients presented with a higher disease severity and had a higher ICU mortality (46.7% vs 12.3% in community-acquired pneumonia-controls; p = 0.002). Twenty-three plasma biomarkers indicative of dysregulation of key host response pathways implicated in sepsis pathogenesis (systemic inflammation, cytokine responses, endothelial cell activation, and barrier function, coagulation activation) were more disturbed in community-acquired pneumonia-macrophage activation-like syndrome patients. Hematologic malignancies were overrepresented in community-acquired pneumonia-macrophage activation-like syndrome patients (33.3% vs 5.1% in community-acquired pneumonia-controls; p = 0.001). In a subgroup analysis excluding patients with hematologic malignancies (n = 141), differences in mortality were not present anymore, but the exaggerated host response abnormalities in community-acquired pneumonia-macrophage activation-like syndrome patients remained.

CONCLUSIONS

Macrophage activation-like syndrome in critically ill patients with community-acquired pneumonia occurs more often in patients with hematologic malignancies and is associated with deregulation of multiple host response pathways.

Pediatric Fibrinogen PART II-Overview of Indications for Fibrinogen Use in Critically Ill Children

Bleeding is frequently seen in critically ill children and is associated with increased morbidity and mortality. Fibrinogen is an essential coagulation factor for hemostasis and hypofibrinogenemia is an important risk factor for bleeding in pediatric and adult settings. Cryoprecipitate and fibrinogen concentrate are often given to critically ill children to prevent bleeding and improve fibrinogen levels, especially in the setting of surgery, trauma, leukemia, disseminated intravascular coagulopathy, and liver failure. The theoretical benefit of fibrinogen supplementation to treat hypofibrinogenemia appears obvious, yet the evidence to support fibrinogen supplementation in children is sparce and clinical indications are poorly defined. In addition, it is unknown what the optimal fibrinogen replacement product is in children and neonates or what the targets of treatment should be. As a result, there is considerable variability in practice. In this article we will review the current pediatric and applicable adult literature with regard to the use of fibrinogen replacement in different pediatric critical care contexts. We will discuss the clinical indications for fibrinogen supplementation in critically ill children and the evidence to support their use. We summarize by highlighting current knowledge gaps and areas for future research.

Platelets parameters in septic shock: clinical usefulness and prognostic value

: Septic shock is a common cause of admission in the ICUs. Despite tremendous improvement in the management modalities, mortality remains high. Early diagnosis and prompt resuscitation are required to improve prognosis. Therefore, identifying a biomarker that could reveal the sepsis at its earlier stage is of paramount importance. In this regards, platelet parameters, such as mean platelet volume, immature platelet fraction and platelet-derived microparticles have been investigated as possible sepsis biomarkers. In fact, haemostasis disturbances are one of the hallmark of septic shock where platelets play a pivotal role in orchestrating the inflammatory response of the host. Moreover, these parameters could have a prognostic value as the severity of the multiorgan dysfunction is correlated with the inflammatory reaction.

The Treatment Effect of Protamine on Severe Coagulopathy in Epstein-Barr Virus-Associated Hemophagocytic Lymphohistiocytosis: Case Reports and Literature Review

Hemophagocytic lymphohistiocytosis (HLH) is a rare and life-threatening disease, which is characterized by severe systemic inflammation with cytokine storm as well as histologic evidence of hemophagocytosis. Besides, coagulopathy and hemorrhages are two common severe complications in HLH patients. Recent literatures indicate that Epstein-Barr virus (EBV) infection is one of the important triggers for the disease. In the study, we present three cases of EBV related HLH (EBV-HLH) with coagulopathy in patients with distinct backgrounds. Case 1 is a 45-year-old female diagnosed with EBV associated NK/T cell lymphoproliferative disorder (EBV-T/NK-LPD) and EBV-HLH. Case 2 is a 17-year-old male with a diagnosis of EBV-T-LPD and EBV-HLH. Case 3 is a 51-year-old male and also diagnosed with EBV-T-LPD and EBV-HLH. All cases were given with treatment with HLH-94 protocol, and the symptoms of the three patients improved. Furthermore, during the treatment, protamine, which has not been reported in the literature previously, was given to the three cases with EBV-HLH, and our results showed that after treatment with protamine, the coagulopathy and bleedings in these patients were improved rapidly. Unfortunately, the three patients relapsed soon and died despite intensive treatment. However, these cases suggest that protamine may serve as a potential treatment option for coagulation associated with EBV-HLH. Besides, the study helps us improve the understanding of the EBV-HLH related coagulation disorders, and provide a potential strategy for future treatment of the disease.

Understanding the andromeda strain - The role of cytokine release, coagulopathy and antithrombin III in SARS-CoV2 critical illness

As the current coronavirus pandemic continues and cases of COVID-19 critical illness rise, physicians and scientists across the globe are working to understand and study its pathophysiology. Part of the pathology of this illness may result from its prothrombotic potential as witnessed from derangements in coagulation and thrombotic complications reported in observational studies performed in China and Europe to findings of microthrombosis upon autopsy analysis of patients who succumbed to COVID-19. Multiple organizations, including the American Society of Hematology (ASH), recommend the routine use of prophylactic heparin to temper the thrombotic complications of this illness given its mortality benefit in severe COVID-19 infections. Reductions in circulating levels of Antithrombin III (AT), the primary mediator of heparin's action, is present in cases of coronavirus related critical illness. AT's use as a prognostic marker, an important effector of heparin resistance, and a potential therapeutic target for COVID-19 remains to be explored.

Clinical Characteristics of Hemophagocytic Lymphohistiocytosis Associated with Non-Hodgkin B-Cell Lymphoma: A Multicenter Retrospective Study

BACKGROUND

Hemophagocytic lymphohistiocytosis (HLH) associated with B-cell lymphoma is a highly aggressive disease with unclear clinical features and has no standard treatment.

PATIENTS AND METHODS

We analyzed the clinical characteristics of 31 patients from two individual centers.

RESULTS

The median overall survival was only 1.5 months. Both univariate and multivariate analyses, based on lymphoma or HLH-related characteristics, revealed that patients with high Epstein-Barr virus (EBV) DNA load and ≥ 2 extranodal lesions, or hypofibrinogenemia, respectively, showed significantly poorer overall survival. Interestingly, some patients with high EBV DNA load had EBV-positive natural killer (NK) and/or T cells, which may be related to the coexistence of immunodeficiency and/or chronic active EBV infection. Molecular genetics examination confirmed that 47.4% (9/19) of patients had complex karyotypes, 37.5% (3/8) of patients had TP53 deletions, and 21.34% (3/14) of patients had TP53 mutation or alteration of malignancy-related pathways, including BCR/NF-κB, JAK-STAT, and epigenetic regulatory pathways, which may provide clues to choose targets for therapy. Treatment regimens containing etoposide, anti-CD20 monoclonal antibodies, or anthracyclines improved patient prognosis (P = .0183, .025, and .0436, respectively). Patients with infections had significantly shorter survival than those without infections (P = .00019).

CONCLUSION

The patients' performance status, number of extranodal lesions, high EBV DNA load, and hypofibrinogenemia are poor prognostic factors for HLH associated with B-cell lymphoma. Molecular genetic high-risk factors are of particular importance because these factors can provide information for prognosis prediction, treatment decisions, and disease surveillance.

The prognostic role of plasma fibrinogen in adult secondary hemophagocytic lymphohistiocytosis

BACKGROUND

In adult patients with secondary hemophagocytic lymphohistiocytosis (sHLH), no valid immune biomarker has been available for predicting the prognosis of untreated sHLH patients.

METHODS

Circulating plasma levels of fibrinogen (FIB) were measured at diagnosis in 293 cases of adult sHLH. We categorized FIB levels into tertiles. Multivariable Cox proportional hazards models were used to evaluate the relationship between FIB and survival. Restricted cubic spline models and two-piecewise Cox proportional hazards models were used to address the nonlinear association between FIB and mortality.

RESULTS

During a median follow-up of 52 (interquartile ranges, 18-221) days, 208 deaths occurred, with 137 deaths in malignancy-associated hemophagocytic lymphohistiocytosis (MHLH) and 71 deaths in non-malignancy-associated hemophagocytic lymphohistiocytosis (non-MHLH). After multivariable adjustment, compared with the highest tertile of FIB, the hazard ratios (HRs) with 95% confidence intervals (CIs) of survival for tertile 2 and tertile 1 were 1.06 (0.90-1.24) and 0.84 (0.71-0.98), respectively. The restricted cubic spline curve displayed a nonlinear and inverse relationship between FIB and mortality. Furthermore, the threshold effect analysis demonstrated that the inflection point for the curve was at an FIB level of 1.76 g/L. The HRs (95% CIs) for survival were 0.68 (0.55-0.83) and 1.08 (0.96-1.21) on the left and right side of the inflection point, respectively.

CONCLUSIONS

These results suggest that plasma fibrinogen is nonlinearly and inversely associated with the risk of mortality in adult secondary hemophagocytic lymphohistiocytosis.

Diagnostic strategy for trigger identification in severe reactive hemophagocytic lymphohistiocytosis: A diagnostic accuracy study

Reactive hemophagocytic lymphohistiocytosis (rHLH) management requires early recognition, trigger identification, and adequate treatment in order to reduce mortality. We assessed the diagnostic yield of tissue biopsies to identify trigger in severe rHLH. We included all consecutive patients presenting an rHLH diagnosis (HLH-2004 criteria) admitted to the intensive care unit (ICU) of a tertiary hospital. This retrospective diagnostic accuracy study was conducted according to the Standards for Reporting Diagnostic Accuracy Statement. Among the 134 included patients (median age 47 years [IQR 47-56]), an underlying immunodeficiency was previously known in 61.2%. rHLH trigger was identified in 127 patients (94.8%) (hematological disorder 75%, infection 16%, systemic disease 4%). Diagnostic yield of tissue biopsies was as follows: lymph node 75% (95% confidence interval [CI], 61-85), skin 50% (95% CI, 27-73), bone marrow 44% (95% CI, 34-55), liver 30% (95% CI, 15-49). Splenectomy (yield 77%; 95% CI, 46-95) was reserved to cases of diagnostic deadlock. Procedural severe adverse events included two cases of reversible hemorrhagic shock. Seventy-eight percent of patients received etoposide regarding to the rHLH severity, and 68% could receive trigger-specific treatment in the ICU. A comprehensive diagnostic workup led to an rHLH trigger identification in 95% of patients, allowing prompt initiation of appropriate therapy. Prospective studies to validate a standardized diagnostic approach are warranted.

Microvascular thrombosis: experimental and clinical implications

A significant amount of clinical and research interest in thrombosis is focused on large vessels (eg, stroke, myocardial infarction, deep venous thrombosis, etc.); however, thrombosis is often present in the microcirculation in a variety of significant human diseases, such as disseminated intravascular coagulation, thrombotic microangiopathy, sickle cell disease, and others. Further, microvascular thrombosis has recently been demonstrated in patients with COVID-19, and has been proposed to mediate the pathogenesis of organ injury in this disease. In many of these conditions, microvascular thrombosis is accompanied by inflammation, an association referred to as thromboinflammation. In this review, we discuss endogenous regulatory mechanisms that prevent thrombosis in the microcirculation, experimental approaches to induce microvascular thrombi, and clinical conditions associated with microvascular thrombosis. A greater understanding of the links between inflammation and thrombosis in the microcirculation is anticipated to provide optimal therapeutic targets for patients with diseases accompanied by microvascular thrombosis.

EBV-positive T/NK-associated lymphoproliferative disorders of childhood: A complete autopsy report

Introduction

Epstein-Barr Virus (EBV)-associated systemic T-cell lymphoproliferative disorder of childhood is a rare but severe manifestation of chronic EBV infection. Despite several case reports characterizing this rare hematological neoplasm, the literature describes extensive heterogeneity in the presentation of this disease.

Case presentation

Here we present a complete autopsy of a 16-year-old girl who ultimately succumbed to EBV-associated systemic T-cell lymphoproliferative disorder of childhood. Her clinical presentation demonstrated a non-specific pharyngitis with positive mono spot test, evolving into fulminant multi-organ failure, disseminated intravascular coagulopathy, sepsis, and ultimately death.

Conclusions

Post-mortem findings included extensive hemorrhage, and infiltration of the liver, spleen, lymph nodes and bone marrow with neoplastic T-cells. There was extensive hemophagocytic lymphohistiocytosis (HLH) within these organs, suggesting overlap between the EBV-associated systemic T-cell lymphoproliferative disorder of childhood and EBV-associated HLH. We hope these findings provide a more comprehensive overview of several possible manifestations of EBV-associated systemic T-cell lymphoproliferative disorder of childhood.

Treatment outcomes and prognostic factors for non- malignancy associated secondary hemophagocytic lymphohistiocytosis in children

BACKGROUND

Secondary hemophagocytic lymphohistiocytosis (HLH) is a rare hyperinflammatory syndrome that requires prompt diagnosis and appropriate treatment. A risk-stratification model that could be used to identify high-risk pediatric patients with HLH who should be considered for second-line therapies, including salvage regimens and allogeneic hematopoietic cell transplantation (HCT), was developed.

METHODS

The medical records of 88 pediatric patients (median age 1.4 years, range 0.2-15 years) with non-malignancy associated secondary HLH were retrospectively reviewed. Treatment strategies included dexamethasone, etoposide, and cyclosporine.

RESULTS

Survival analysis showed HLH patients with infections other than Epstein-Barr virus (EBV) and unknown causes experienced better 5-year overall survival (OS) than patients with HLH due to autoimmune disease, EBV or immunodeficiency (76% vs. 65, 33.3, 11%, p < 0.001). On multivariate analysis, among all patients, non-response at 8 weeks was the most powerful predictor of poor OS. When treatment response was excluded, hemoglobin < 60 g/L and albumin < 25 g/L at diagnosis were associated with poor OS. In patients with EBV-HLH, hemoglobin < 60 g/L at diagnosis was associated with poor OS. A prognostic risk score was established and weighted based on hazard ratios calculated for three parameters measured at diagnosis: hemoglobin < 60 g/L (2 points), platelets < 30 × 10⁹/L (1 point), albumin < 25 g/L (2 points). Five-year OS of low-risk (score 0-1), intermediate-risk (score 2), and poor-risk (score ≥ 3) patients were 88, 38, and 22%, respectively (p < 0.001).

CONCLUSIONS

These findings indicate that clinicians should be aware of predictive factors at diagnosis and consider 8-week treatment response to identify patients with high-risk of disease progression and the need for second-line therapy and allogeneic HCT.

Severe cerebral involvement in adult-onset hemophagocytic lymphohistiocytosis

•

HLH in adults can result in acute necrotizing encephalitis and severe hemorrhagic brain disease due to disseminated intravascular coagulation (DIC).

•

Observation of DIC in patients with HLH should prompt neuroimaging evaluation as brain hemorrhage is a potentialcomplication.

•

HLH (or CSS in COVID-19 patients) -related brain injury should be considered in patients with appropriate systemic manifestations as early diagnosis and treatment are crucial.

The diagnosis of hemophagocytic lymphohistiocytosis (HLH) with cerebral involvement is challenging given the rarity of HLH and its resemblance to the much more common severe sepsis. Timely diagnosis and treatment may be lifesaving. We report two cases demonstrating different and rare forms of severe brain involvement in adult patients with HLH: acute necrotizing encephalopathy, and diffuse hemorrhagic disease due to disseminated intravascular coagulation. Severe HLH with brain involvement in adults is rare. HLH with cerebral involvement should be considered in patients presenting with severe systemic inflammatory response syndrome (SIRS) but negative cultures and unusual or unexpectedly severe clinical and/or radiologic signs of cerebral dysfunction. Similar brain injury may occur in patients with cytokine storm syndrome due to COVID-19.

Background

Hemophagocytic lymphohistiocytosis (HLH) presents with fevers, rash, organomegaly, cytopenia, and increased triglycerides and ferritin (Ramos-Casals et al., 2014) [1]. Neurologic abnormalities are reported in about one-third of patients (Cai et al., 2017), including a few cases of acute necrotizing encephalopathy (ANE) (Xiujuan et al., 2015). Coagulation abnormalities are frequent in HLH patients (Valade et al., 2015).

Objective

To raise awareness about the importance of early diagnosis and treatment of HLH with neurological involvement to prevent serious complications and demise.

Coagulation Disorders in Hemophagocytic Lymphohistiocytosis/Macrophage Activation Syndrome

Hemophagocytic lymphohistiocytosis (HLH) is a rare and severe condition that can lead patients to the intensive care unit. HLH diagnosis may be challenging, as it relies on sets of aspecific criteria. Several organ dysfunctions have been described during HLH, including hemostasis impairment found in more than half of the patients. The most frequently reported anomaly is a decrease in the fibrinogen level, which has been associated with higher mortality rates. Coagulation impairment study in patients with HLH represents an interesting field of research, as little is known about the mechanism leading to hypofibrinogenemia.

Hemophagocytic Lymphohistiocytosis and Other Culture Negative Sepsis-Like Syndromes in the ICU

There are many sepsis-like inflammatory syndromes that may be encountered by critical care practitioners. Clinically, these syndromes may imitate sepsis and are often identified after an extensive, but unrevealing evaluation for infection. In some instances, these syndromes are anticipated complications of advanced therapies for malignancy. It is vitally important to identify these disorders and treat them with specific chemotherapeutic or immunomodulating therapies. This chapter will focus on hemophagocytic lympho-histiocytosis (HLH), a rare disorder of pathologic immune system activation that presents as a sepsis-like illness in the critically ill. While treatment of HLH with chemotherapy and immunosuppression should be guided by an expert hematologist, the diagnosis is often made by the critical care medicine practitioner. We present a case illustrating the challenges of defining this syndrome in a patient with recurrent critical illness, and review the evidence underlying diagnostic and prognostic criteria for this protean syndrome. We also review several of the more common sepsis-like inflammatory syndromes that are encountered in the critical care unit along with their specific treatments.

Serum high mobility group box protein 1 (HMGB1) levels reflect clinical features of childhood hemophagocytic lymphohistiocytosis

Purpose

Hemophagocytic lymphohistiocytosis (HLH) is a potentially lethal hyperinflammatory disorder. For further understanding of the pathogenesis of HLH, we examined serum levels of high mobility group box protein 1 (HMGB1) in children with HLH.

Patients and methods

Serum HMGB1 levels were measured in 28 patients with HLH and 6 normal controls using a quantitative enzyme-linked immunosorbent assay. The patients were 21 boys and 7 girls, aged from 10 days to 21 years, with a median age of 8.5 years. The underlying conditions of HLH were infection-associated HLH in 18 patients, malignancy-associated HLH in 7 patients, and genetic HLH in 3 patients. The relations between serum HMGB1 levels and clinical symptoms and laboratory parameters were analyzed.

Results

Serum HMGB1 levels were significantly higher in patients with HLH than in normal controls (median, 6.5 ng/mL, interquartile range, 4.25–13.1). The serial serum HMGB1 levels in one patient fell to reflect the disease activity. Serum HMGB1 levels were significantly higher in patients with disseminated intravascular coagulation (DIC) than in patients without DIC (p<0.001) and were also significantly higher in patients with central nervous system (CNS) complications than in patients without CNS complications (p<0.01). Serum HMGB1 levels were positively correlated with aspartate aminotransferase (r_s =0.48, p<0.01, Spearman’s rank correlation coefficient) and negatively correlated with fibrinogen (r_s = −0.475, p=0.011) and hemoglobin (r_s = −0.465, p=0.013).

Conclusion

Serum HMGB1 levels reflect clinical features of childhood HLH. HMGB1 is a potential mediator involved in the pathogenesis and determining the clinical findings of HLH.

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.

Pneumococcal Bacteremia Complicated by Hemophagocytic Lymphohistiocytosis

From pneumonia to pericarditis, from sepsis to splenic abscess, Streptococcus pneumoniae is the causative agent of a diverse array of pyogenic disease. With the introduction of vaccines and effective antibiotic treatments, the incidence of complicated streptococcal infection has declined. We report a case of S. pneumoniae bacteremia, in the setting of occult sinusitis, complicated by hemophagocytic lymphohistiocytosis (HLH), disseminated intravascular coagulation (DIC), and recurrent pneumococcal infection. Although severe streptococcal infection has been associated with immunodeficiency or splenectomy, no such predisposition was identified in our patient. We discuss the association of streptococcal infection with HLH and DIC and review occult sinusitis as a source of pneumococcal bacteremia, with the goal of enhancing the "illness scripts" of general medical practitioners to include such entities.

Intensive care unit complications and outcomes of adult patients with hemophagocytic lymphohistiocytosis: A retrospective study of 16 cases

AIM

To study the management, complications and outcomes of adult patients admitted with hemophagocytic lymphohistiocytosis (HLH) in the intensive care unit (ICU).

METHODS

We performed a retrospective observational study of adult patients with the diagnosis of “HLH” admitted to the two academic medical ICUs of Baylor College of Medicine between 01/01/2013 to 06/30/2017. HLH was diagnosed using the HLH-2004 criteria proposed by the Histiocyte Society.

RESULTS

Sixteen adult cases of HLH were admitted to the medical ICUs over 4 years. Median age of presentation was 49 years and 10 (63%) were males. Median Sequential Organ Failure Assessment (SOFA) score at the time of ICU admission was 10. Median ICU length of stay (LOS) was 11.5 d and median hospital LOS was 29 d. Septic shock and acute respiratory failure accounted for majority of diagnoses necessitating ICU admission. Septic shock was the most common ICU complication seen in (88%) patients, followed by acute kidney injury (81%) and acute respiratory failure requiring mechanical ventilation (75%). Nine patients (56%) developed disseminated intravascular coagulation and eight (50%) had acute liver failure. 10 episodes of clinically significant bleeding were observed. Multi system organ failure was the most common cause of death seen in 12 (75%) patients. The 30 d mortality was 37% (6 cases) and 90 d mortality was 81% (13 cases). There was no difference in mortality based on age (above or less than 50 years), SOFA score on ICU admission (more than or less than 10), immunosuppression, time to diagnose HLH or direct ICU admission versus floor transfer.

CONCLUSION

HLH is a devastating disease associated with poor outcomes in ICU. Intensivists need to have a high degree of clinical suspicion for HLH in patients with septic shock/multi system organ failure and progressive bi/pancytopenia who are not responding to standard management in ICU.

Management of Hemophagocytic Lympho-Histiocytosis in Critically Ill Patients

Hemophagocytic syndrome remains a rare but life-threatening complication and is associated with intensive care unit (ICU) admission. The pathophysiology is based on a defect of cytotoxicity in T cells that results in a state of hyperinflammation in the presence of a trigger. As a consequence, patients may develop multiorgan failure. The diagnosis of hemophagocytic syndrome (HS) remains difficult and relies on persistant high-grade fevers in the absence of infection and on constellation of laboratory parameters. However, prompt diagnosis and treatment (supportive care and specific treatment) are associated with improved outcome. Interaction with other specialists (hematologist, internist) may improve the diagnosis and treatment strategy. This article describes diagnostic tools, organ failures associated with HS, main etiologies, and management.

A Case of Human Immunodeficiency Virus -triggered Hemophagocytic Lymphohistocytosis Presenting with Severe Bleeding Tendency

Human immunodeficiency virus (HIV) is one of the less common triggers of secondary hemophagocytic lymphohistiocytosis (HLH) in which coagulation disorder is a frequent manifestation. Here, we present a case of HIV-triggered secondary HLH presenting with severe bleeding tendency and fever. Despite high-dose dexamethasone infusion (10 mg/body surface area/day), progressive disseminated intravascular coagulation and thrombocytopenia resulted in massive hemathochezia: the bleeding episode ceased after endoscopic hemoclipping. After then, he took a highly-active antiretroviral therapy (HAART). Eventually, body temperature and overall laboratory findings normalized in response to HAART. Clinicians should not overlook HIV infection as a possible trigger of secondary HLH. In such cases, HAART is the core treatment.

Prognostic Factors of Death in 151 Adults With Hemophagocytic Syndrome: Etiopathogenically Driven Analysis

Objective

To characterize the etiologies and clinical features at diagnosis of patients with hemophagocytic lymphohistiocytosis (HLH) and correlate these baseline features with survival using an etiopathogenically guided multivariable model.

Patients and Methods

The Spanish Group of Autoimmune Diseases HLH Study Group, formed in 2013, is aimed at collecting adult patients with HLH diagnosed in internal medicine departments between January 3, 2013, and October 28, 2017.

Results

The cohort consisted of 151 patients (91 men; mean age, 51.4 years). After a mean follow-up of 17 months (range, 1-142 months), 80 patients died. Time-to-event analyses for death identified a worse survival curve for patients with neoplasia (P<.001), mixed microbiological infections (P=.02), and more than 1 infection (P=.01) and glucocorticoid monotherapy (P=.02). According to univariate analyses, platelets of less than 100,000/mm³ (hazard ratio [HR], 3.39; 95% CI, 1.37-8.40), leukopenia (HR, 1.81; 95% CI, 1.01-3.23), severe hyponatremia (HR, 1.61; 95% CI, 1.02-2.54), disseminated intravascular coagulation (HR, 1.87; 95% CI, 1.05-3.34), bacterial infection (HR, 1.99; 95% CI, 1.09-3.63), mixed microbiological infections (HR, 3.42; 95% CI, 1.38-8.46), and 2 or more infectious triggers (HR, 2.95; 95% CI, 1.43-6.08) were significantly associated with death. In contrast, peripheral adenopathies (HR, 0.63; 95% CI, 0.40-0.98) and the immunosuppressive drug/intravenous immunoglobulin/biological therapies (HR, 0.44; 95% CI, 0.20-0.96) were protective against all-cause mortality. Multivariable Cox proportional hazards regression analysis identified 2 or more infectious triggers (HR, 3.14; 95% CI, 1.28-7.68) as the only variable independently associated with death.

Conclusion

The mortality rate of adult patients diagnosed with HLH exceeds 50%. Infection with more than 1 microbiological agent was the only independent variable associated with mortality irrespective of the underlying disease, epidemiological profile, clinical presentation, and therapeutic management.

[Hemophagocytic Lymphohistiocytosis]

Hemophagocytic Lymphohistiocytosis Abstract. Hemophagocytic lymphohistiocytosis (HLH) is a group of rare diseases characterized by over-activation of the immune system. They form two groups: primary and secondary HLH. Primary HLH are linked to mutations impairing lymphocyte cytotoxicity. Secondary HLH are triggered by infections, autoimmune diseases or neoplasia, the remaining cases being labeled idiopathic. HLH manifest as febrile states, cytopenias and hepatosplenomegaly. In the absence of treatment, they quickly lead to multiple organ failure. The diagnosis is currently based on the presence of several clinical and biological markers. Treatment consists of suppression of the triggering factor, organ support and immunosuppression. Primary forms, affecting a pediatric population, have been the subject of intense research, and are nowadays treated with established therapeutic protocols. Several recent retrospective studies have improved our knowledge of secondary HLH, which affects mostly adults and whose incidence seems to be increasing. Thus, new diagnostic criteria are currently being studied for secondary HLH, and several treatment protocols have just been published or are being evaluated.

A prospective quality improvement initiative in adult hemophagocytic lymphohistiocytosis to improve testing and a framework to facilitate trigger identification and mitigate hemorrhage from retrospective analysis

Hemophagocytic lymphohistiocytosis (HLH) is a highly fatal, hyperinflammatory syndrome in adults triggered by an underlying illness in most cases. As such, suspicion of HLH dictates further investigation to identify the HLH trigger and determine treatment. HLH is clinically challenging due to diverse presentations and underlying triggers, provider unfamiliarity, and bleeding complications. Clinically, we observed diagnostic error from incorrect testing and cognitive biases (interleukin-2 confused with soluble interleukin-2 receptor and natural killer cell quantification confused with functional assays).This study reports our single institutional experience with adult HLH with the aim to reduce erroneous testing with a quality improvement (QI) project, and to facilitate trigger discovery and mitigate hemorrhage. Provider education on HLH testing was the prospective intervention, followed by mistaken test removal. HLH triggers and diagnostic utility were determined by retrospective chart review. Risk factors for hemorrhage were determined by multivariable analysis.Erroneous HLH testing was reduced from 74% to 24% of patients (P < .001) by the QI intervention. These changes were projected to save $11,700 yearly. The majority (64%) of patients evaluated for HLH were on non-hematology/oncology services, highlighting the need for vigilance in hematology consultation. Sixty-three patients met classic HLH-2004 criteria for HLH. Malignancy (38%), infection (27%), Epstein-Barr virus (EBV) (14%), or autoimmune disease (8%) triggered most HLH cases. HLH triggers were most commonly identified by serologic testing (27%) and bone marrow biopsy (19%). Biopsy of other affected organs based on PET-CT imaging after unsuccessful initial diagnostic measures was helpful, and focal fluorodeoxyglucose uptake was predictive of an underlying malignancy (likelihood ratio 8.3, P = .004). Major hemorrhage occurred in 41% of patients. On multivariable analysis the odds ratios (OR) for major hemorrhage were increased for patients with intensive care unit level care (OR 10.47, P = .005), and disseminated intravascular coagulation in the first week of admission (OR 10.53, P = .04).These data are incorporated into a framework to encourage early HLH recognition with the HScore, facilitate trigger identification, identify those at risk for hemorrhage, and minimize low-yield or erroneous testing.

Prognostic Factors and Outcomes in Adults With Secondary Hemophagocytic Lymphohistiocytosis: A Single-center Experience

INTRODUCTION

Hemophagocytic lymphohistiocytosis (HLH) is a disorder caused by severe immune activation. There are no specific criteria to establish the diagnosis in adults; however, the HLH-04 criteria are among the most commonly used. The HScore is a non-validated tool that can also be useful for HLH diagnosis.

PATIENTS AND METHODS

We describe the prognostic factors and outcomes of 64 adults diagnosed with HLH in a reference medical center in Mexico City. We included patients ≥ 18 years with HLH, diagnosed and treated at our institution from 1998 to 2016.

RESULTS

The median age was 35 years (range, 18-77 years). The underlying cause of HLH was lymphoma in 33 (51.56%) patients (MA-HLH). Cutaneous involvement was more frequent in MA-HLH (33.33%), when compared with patients with non-malignancy associated HLH (NM-HLH) (9.68%) (P = .022). Neurologic symptoms were more frequent in NM-HLH (25.81%) versus MA-HLH (6.06%) (P = .032). After a median follow-up of 14 months (range, 0-216 months), 30-day mortality was 26.56%. Three-year overall survival (OS) was higher for patients with MA-HLH compared with patients with NM-HLH (41% vs. 22.5%; P = .046). Multivariate analysis showed that the presence of nosocomial infection and neurologic symptoms were statistically significant predictors of inferior OS (P = .034 and P = .033, respectively).

CONCLUSION

In this series of adults with HLH, patients with nosocomial infections and neurologic symptoms had a statistically significant worse OS. In the largest series in Latin America, the most common cause of HLH was T-cell lymphoma. In our population, NM-HLH presented a higher mortality.

Syndrome d’activation macrophagique d’origine infectieuse : le point de vue du réanimateur

Le syndrome hémophagocytaire (SH) se présente classiquement sous la forme de cytopénies fébriles accompagnées d’un syndrome tumoral, le plus souvent dans le cadre d’un déficit immunitaire sous-jacent. Les formes les plus sévères s’accompagnent de défaillances d’organes qui peuvent conduire le patient en réanimation. Les principales étiologies de SH sont les infections, les hémopathies et les maladies de système. Les infections associées au SH sont majoritairement virales, liées à l’EBV, au CMV et aux autres virus du groupe herpes. Les infections bactériennes sont dominées par les mycobactéries, et les parasites sont essentiellement représentés par la leishmaniose et la toxoplasmose. Enfin, parmi les infections fongiques, l’histoplasmose est à rechercher en priorité. La prise en charge thérapeutique du SH associé aux infections comprend trois volets : le traitement de l’infection, les traitements de support et le traitement du SH. Les principaux traitements proposés dans le cadre du SH associé aux infections sont les corticoïdes, les immunoglobulines polyvalentes et l’étoposide. À la phase initiale, c’est principalement la gravité des patients (défaillances d’organes) qui guidera la décision d’administrer ou non un traitement spécifique du SH. Un aspect important de la prise en charge thérapeutique est la recherche systématique d’un déficit immunitaire sous-jacent, qui pourra faire l’objet d’une prise en charge spécifique. Le bilan minimal comprendra la recherche d’une infection par le VIH, la recherche d’une hémopathie lymphoïde sous-jacente (maladie de Hodgkin, lymphome non hodgkinien, maladie de Castleman) et la recherche d’arguments en faveur d’une maladie systémique (Lupus et maladie de Still).