Silencing the cytokine storm: the use of intravenous anakinra in haemophagocytic lymphohistiocytosis or macrophage activation syndrome

Hemophagocytic lymphohistiocytosis in pregnancy-a case report

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening condition that is a rare occurrence in pregnancy and can be elusive in its diagnosis thereby delaying treatment. We report the case of a 30-year-old female patient at 36 weeks of pregnancy who presented with a persistent fever that did not respond to antibiotics. After we investigated her thoroughly, considering the persistent fever, we performed a bone marrow biopsy as part of the workup for prolonged pyrexia. We diagnosed her with HLH secondary to cytomegalovirus pneumonia. As her laboratory investigations fulfilled the criteria for HLH we treated her with the appropriate therapy using a multidisciplinary approach, resulting in her complete recovery. HLH should be considered a potential differential diagnosis in pregnant patients complaining of persistent fever, cytopenia, or declining clinical condition despite delivery of the baby.

Protective Effects of Interleukin-1 Inhibition With Anakinra in Mouse Models of Ischemic Stroke With and Without Reperfusion

BACKGROUND

Severe brain ischemia is associated with life-threatening edema and inflammation. Interleukin-1 is a crucial mediator of inflammation, and its blockade showed benefits in experimental stroke. We studied anakinra, a modified recombinant human interleukin-1 receptor antagonist, in mouse models of moderate to severe ischemia/reperfusion and large hemispheric infarctions. Due to anakinra's short half-life, we used a novel subcutaneous infusion protocol and tested 2 drug doses.

METHODS AND RESULTS

We performed transient or permanent intraluminal middle cerebral artery occlusion (MCAo) in male C57BL/6J and Balb/c mice, the latter of which have poorer collaterals. Mice received a subcutaneous anakinra bolus (24 mg/kg), followed by continuous infusion of either 24 or 120 mg/kg per day, starting at reperfusion or 15 minutes after permanent MCAo. We evaluated acute (24 hours/48 hours) infarct volume and edema by magnetic resonance imaging, neurological function, and inflammatory responses. The mortality rate tended to be higher in Balb/c compared with C57BL/6J mice. In both strains, prolonged ischemia expanded the infarct size, with intraluminal permanent MCAo resulting in larger hemispheric infarctions and edema than transient MCAo. The high dose of anakinra reduced infarct volume and inflammation in C57BL/6 mice and improved the functional deficits in Balb/c mice following transient MCAo. It also showed a trend toward reducing infarction and edema after permanent MCAo in C57BL/6 mice.

CONCLUSIONS

The study demonstrates that a high dose of anakinra improves outcomes in mouse models of moderate infarction following ischemia/reperfusion, whereas its effect was less pronounced in a malignant hemispheric infarction model without reperfusion, where only a nonsignificant trend toward protection was observed.

Off-Label Use of Anakinra in Inflammatory Conditions in Neonates and Infants Up to 3 Months of Age: A Case Series and a Review of the Literature

BACKGROUND

Anakinra is an interleukin-1 receptor antagonist (IL-1Ra). Since IL-1 has been shown to play a key role in the etiology of different autoinflammatory diseases, blocking its pathway has become an important therapeutic target, even in neonates.

AIMS

We aimed to report our experience in using anakinra to treat specific neonatal inflammatory conditions.

METHODS

We described the clinical management with anakinra of five cases of neonates or infants up to 3 months of age admitted to the neonatal intensive care unit (NICU) of Bambino Gesù Children's Hospital IRCCS in Rome (Italy) from 2020 onwards. Medical history and clinical data concerning NICU hospitalization were collected from the electronic medical records. Furthermore, we performed a literature review of off-label anakinra in the first 3 months of life, up to 5 April 2024. We excluded from this review cases of cryopyrin-associated periodic syndrome, deficiency of the interleukin-1 receptor antagonist, and mevalonate kinase deficiency, for which anakinra is a known treatment.

RESULTS

We reported three off-label cardiorespiratory reasons to use IL-1Ra from our series: (i) chronic lung disease with pulmonary hypertension, (ii) interstitial lung disease with pulmonary hypertension to facilitate the weaning from respiratory support, and (iii) post-surgical polyserositis if effusions accumulate despite drainage. In all our patients, the drug was administered at a dosage of 10 mg/kg/day. The route of administration was chosen based on the patient's clinical characteristics, with the subcutaneous and intravenous routes being comparable in efficacy. The duration of therapy was modulated based on the patient's clinical response, with a minimum duration of 4 months. A total of 308 retrieved articles were screened, and then full texts of records deemed eligible for inclusion were assessed. Based on the literature search and our five cases, a total of 17 infants were treated with anakinra outside its approved indications. The major off-label use was for hemophagocytic lymphohistiocytosis/macrophage activation syndrome, followed by multisystem inflammatory syndrome in children and Kawasaki disease, as in two of our cases.

CONCLUSIONS

According to the results of our case series and review of the literature, the off-label use of anakinra in neonates with inflammatory conditions refractory to first-line therapy could be considered. Prospective, multicenter research is necessary to determine whether anakinra is a safe treatment option for these infants to prevent early inflammatory illnesses and in which situations it could enhance clinical results.

Perspectives on the current diagnostic and treatment paradigms in secondary hemophagocytic lymphohistiocytosis (HLH)

Improved awareness of hemophagocytic lymphohistiocytosis (HLH) among clinicians has led to an increase in its diagnosis. Often diagnosis is made based on the HLH- 2004 criteria. While these criteria have considerable strengths, they lack specificity and may be fulfilled in the setting of many pro-inflammatory disorders. Genetic defects affecting cellular cytotoxicity cause familial (primary) HLH. On the other hand, secondary HLH is more a pathophysiologic process common to many conditions, rather than a singular disease entity. Improved genetic, immunologic, and functional testing have changed not only the way we diagnose HLH, but also how we treat it. In 2004, there were few active agents and regimens. In 2024, there are multiple safe and effective targeted therapies. We have begun to understand that routine and immediate use of etoposide-based therapy in secondary HLH is likely not appropriate, and emerging cytokine-directed therapies may be more rational interventions. Moreover, it is recognized that identifying and treating the driver of secondary HLH is at least as important as treating the cytokine storm and immune dysregulation. Unfortunately, over-reliance on, and narrow interpretation of, the HLH- 2004 criteria can lead to overdiagnosis, misdiagnosis, and unneeded exposure to drugs that can be harmful. It is important that clinicians understand the limitations of the current diagnostic paradigms for secondary HLH, and the shortcomings of reflexive use of etoposide-based therapy. Herein we will discuss the pros and cons of the current paradigm for the recognition, diagnosis, and treatment of secondary HLH.

Macrophage Activation Syndrome

Macrophage activation syndrome (MAS) is a state of immune hyperactivation that can result in life-threatening multisystem end-organ dysfunction. Often termed a "cytokine storm," MAS occurs among the rheumatic diseases most typically in Still's disease but also in systemic lupus erythematosus and Kawasaki disease. MAS can also accompany infection, malignancy, and inborn errors of immunity. This review provides a practical, evidence-based guide to the understanding, recognition, and management of MAS in children and adults, with a primary focus on MAS complicating Still's disease.

Immune Effector Cell-associated Hemophagocytic Lymphohistiocytosis-like Syndrome (IEC-HS)

Immune effector cell-associated hemophagocytic lymphohistiocytosis-like syndrome (IEC-HS) is a complication of adoptive cell therapy. Presenting with clinical manifestations of hyperinflammation and surrogate indicators of hyperinflammation such as elevations in serum ferritin and hepatic transaminases, decreasing cell counts, and hypofibrinogenemia, IEC-HS resembles primary and other forms of secondary hemophagocytic lymphohistiocytosis. Nonetheless, this is an iatrogenic complication resulting from the induction of hyperinflammatory pathways during T-cell-mediated anticancer targeting. Distinct from cytokine release syndrome, IEC-associated neurotoxicity syndrome, and IEC-associated hematotoxicity, IEC-HS can be life-threatening. Identification of IEC-HS, optimization of treatment strategies, and use of supportive care are critical to improving outcomes.

Macrophage activation syndrome successfully treated with eculizumab and emapalumab: a case report

Hemophagocytic lymphohistiocytosis (HLH) is a hyperinflammatory syndrome, often referred to as macrophage activation syndrome (MAS) in the context of autoimmune disease-induced forms. We report the case of a 41-year-old woman with a previous diagnosis of Crohn's disease complicated by dermatomyositis, who was admitted in our hospital for the acute onset of fever, pancytopenia, and disseminated intravascular coagulation (DIC). The laboratory findings documented hyperferritinemia, hypertransaminasemia, increased lactate-dehydrogenase (LDH), hypertriglyceridemia, and elevation of inflammatory indices, along with complement consumption. MAS was confirmed by examination of the bone marrow. Consequently, the patient was treated with high doses of glucocorticoids, subcutaneous anakinra, and intravenous immunoglobulin (IVIg). Due to the persistence of signs of thrombotic microangiopathy, we started therapy with eculizumab which stabilized the patient without improvement, so we added emapalumab, resulting in clinical improvement and normalization of blood tests.

Macrophage Activation Syndrome in Kawasaki Disease: Insights from a Systematic Literature Review on Diagnosis, Clinical Features, and Treatment

BACKGROUND

Macrophage activation syndrome (MAS) is a hyperinflammatory and potentially fatal complication associated with rheumatologic disorders. In Kawasaki disease (KD), MAS is a rare and poorly described condition, making its differentiation from a severe, treatment-resistant presentation of KD particularly challenging.

OBJECTIVE

We aimed to describe MAS in KD by analyzing its epidemiological, clinical, and laboratory characteristics, complications, therapeutic strategies, and outcomes.

METHODS

A comprehensive literature review of PubMed, Embase, Scopus, and Cochrane Library was conducted to identify English-language studies on KD complicated by MAS, including case reports and case series, until 15 November 2024.

RESULTS

A total of 176 pediatric patients (60 females; median age 4 years, range 0.13-17) from 48 articles were included. MAS occurred after or simultaneously with KD diagnosis in 174/176 cases (99%). Common features included fever (100%), splenomegaly (49.4%), and hyperferritinemia (98.2%). Cardiac involvement was reported in 37% of children. The HLH-2004 criteria were met in 63% of cases, while the 2016 Ravelli criteria for MAS complicating systemic juvenile idiopathic arthritis were met in 94%. Treatment included additional doses of IVIG (36.2%), GCs (82.8%), cyclosporine A (28.7%), and biologics (13.8%), with complete MAS resolution in 93% of cases.

CONCLUSIONS

MAS in KD is a rare but severe complication, with overlapping features that make its differentiation from severe and resistant KD challenging. Persistent fever despite initial IVIG administration, along with splenomegaly and hyperferritinemia, emerge as key warning signs. Ravelli criteria provide stronger diagnostic support compared to the HLH-2004 criteria. Moreover, MAS is associated with increased cardiac involvement.

Macrophage Activation Syndrome in Adult-Onset Still's Disease: Challenges in Early Detection and Management

Adult-onset Still's disease (AOSD) is an immunological disorder that manifests with fever, evanescent rash, leukocytosis, and arthralgia. One of the most severe complications of AOSD is macrophage activation syndrome, a life-threatening complication characterized by hyperactivation of the immune system and multiorgan dysfunction. This case report describes a 24-year-old female who developed macrophage activation syndrome in the setting of AOSD. Initially, she developed heterogeneous and nonspecific symptoms of fever, pharyngitis, rash, lymphadenopathy, and migratory arthralgia after a trip to Mexico. Thus, the diagnosis and appropriate treatment were delayed. Although her symptoms were temporarily relieved with oral steroids, she worsened clinically. She developed a widespread rash, persistent fever, a very high ferritin level (29,972 ng/mL), and elevated liver enzymes with mild hepatosplenomegaly, raising concern for macrophage activation syndrome. After ruling out infections, she was diagnosed with AOSD, and treatment with intravenous steroids was started, resulting in clinical improvement. Macrophage activation syndrome is a rare but fatal complication. Early recognition, particularly with elevated ferritin, liver dysfunction, and thrombocytopenia, is very important. Early intervention with glucocorticoids and biologics like anakinra is crucial for improving outcomes. The patient is in remission with ongoing follow-up with rheumatology.

Immunobiology and immunotherapy of COVID-19

The SARS-CoV-2 outbreak in late 2019 triggered a major increase in activities related to immunobiology and immunotherapy to cope with and find solutions to end the COVID-19 pandemic. The unprecedented approach to research and development of drugs and vaccines against SARS-CoV-2 has substantially improved the understanding of immunobiology for COVID-19, which can also be applied to other infectious diseases. Major efforts were dedicated to the repurposing of existing antiviral drugs and the development of novel ones. For this reason, numerous approaches to evaluating interferons, immunoglobulins, and cytokine inhibitors have been conducted. Antibody-based therapies, especially employing monoclonal antibodies have also been on the agenda. Cell-based therapies involving dendritic cells, macrophages, and CAR T-cell approaches have been evaluated. Many existing antiviral drugs have been repurposed for COVID-19 and novel formulations have been tested. The extraordinarily rapid development of efficient vaccines led to the breakthrough of novel vaccine approaches such as mRNA-based vaccines saving millions of lives. Waning immunity of existing vaccines and emerging SARS-CoV-2 variants have required additional booster vaccinations and re-engineering of new versions of COVID-19 vaccines.

Association of circulating cytokine levels and tissue-infiltrating myeloid cells with achalasia: results from Mendelian randomization and validation through clinical characteristics and single-cell RNA sequencing

BACKGROUND

Achalasia is a rare motility disorder of the esophagus often accompanied by immune dysregulation, yet specific underlying mechanisms remain poorly understood.

METHODS

We utilized Mendelian randomization (MR) to explore the causal effects of cytokine levels on achalasia, with cis-expression/protein quantitative trait loci (cis-eQTLs/pQTLs) for 47 cytokines selected from a genome-wide association study (GWAS) meta-analysis and GWAS data for achalasia obtained from FinnGen. For cytokines significantly linked to achalasia, we analyzed their plasma concentrations and expression differences in the lower esophageal sphincter (LES) using enzyme-linked immunosorbent assay and single-cell RNA sequencing (scRNA-seq) profiling, respectively. We further employed bioinformatics approaches to investigate underlying mechanisms.

RESULTS

We revealed positive associations of circulating Eotaxin, macrophage inflammatory protein-1b (MIP1b), soluble E-selectin (SeSelectin) and TNF-related apoptosis-inducing ligand (TRAIL) with achalasia. When combining MR findings with scRNA-seq data, we observed upregulation of TRAIL (OR = 2.70, 95% CI, 1.20-6.07), encoded by TNFSF10, in monocytes and downregulation of interleukin-1 receptor antagonist (IL-1ra) (OR = 0.70, 95% CI 0.59-0.84), encoded by IL1RN, in FOS_macrophages in achalasia. TNFSF10high monocytes in achalasia displayed activated type I interferon signaling, and IL1RNlow FOS_macrophages exhibited increased intercellular communications with various lymphocytes, together shaping the proinflammatory microenvironment of achalasia.

CONCLUSIONS

We identified circulating Eotaxin, MIP1b, SeSelectin and TRAIL as potential drug targets for achalasia. TNFSF10high monocytes and IL1RNlow macrophages may play a role in the pathogenesis of achalasia.

A rare case of orbital inflammation complicated by hemophagocytic lymphohistiocytosis

We report a rare case of orbital inflammation complicating hemophagocytic lymphohistiocytosis (HLH) patient. HLH is a rare, life-threatening disorder characterized by uncontrolled activation of cytotoxic T lymphocytes, natural killer cells, and macrophages. A 37-year-old man known to have HLH, presented with a left periorbital swelling that was unsuccessfully treated as an orbital cellulitis, with intravenous antibiotics. A computed tomography (CT) scan of the orbits revealed inflammatory changes with no orbital collection or paranasal sinus disease. An orbital biopsy demonstrated lymphoplasmacytic infiltrations admixed with histiocytes. The patient deteriorated and was admitted to the intensive care unit. Ensuing blood results supported a diagnosis of HLH, and the patient responded well to subsequent immunosuppression. This case report highlights the importance of re-considering the diagnosis of orbital cellulitis in treatment resistant cases, particularly in the absence of sinus disease. To our knowledge, this is the third case of orbital inflammation associated with HLH patients.

Hemophagocytic Lymphohistiocytosis in a Critically Ill Patient: A Case Report of a Potentially Fatal Entity

Background

Hemophagocytic lymphohistiocytosis (HLH) is a non-neoplastic proliferation and macrophage activation that induces cytokine-mediated bone marrow suppression and features of intense phagocytosis in the bone marrow and liver, leading to multi-organ dysfunction and ultimate failure. The diagnosis of HLH in an intensive care setting is challenging, and it is associated with high morbidity and mortality. HLH-94 is the standard protocol for treatment, consisting of dexamethasone and chemotherapy like etoposide.

Case Presentation

We present the case of a 73-year-old woman who had a prolonged hospitalization for vomiting, diarrhea, and dehydration. Her conditions were complicated by acute refractory pancytopenia on the 12th day of admission, leading to multi-organ failure, including anuric renal failure requiring renal replacement therapy and respiratory failure requiring intubation. After a thorough workup, she was diagnosed with HLH using HLH-2004 diagnostic criteria and confirmed by a bone marrow biopsy. She was started on supportive therapy and high-dose intravenous dexamethasone with an appropriate clinical response. Her pancytopenia improved, and she no longer required ventilator support for respiratory failure or dialysis for renal failure. Unfortunately, her hospital course was complicated by a sentinel event leading to her death.

Conclusion

This case emphasizes that early recognition and treatment initiation of HLH are crucial to prevent adverse outcomes and mortality. Treatment should be tailored based on the underlying HLH trigger, as chemotherapy-based treatment regimens may result in overtreatment and unnecessary toxicities. Further studies are needed to increase clinicians' awareness and management of secondary cases of HLH.

A Novel Engineering Cell Therapy Platform Mimicking the Immune Thrombocytopenia-Derived Platelets to Inhibit Cytokine Storm in Hemophagocytic Lymphohistiocytosis

Hemophagocytic lymphohistiocytosis (HLH) is a common and highly fatal hyperinflammatory syndrome characterized by the aberrant activation of macrophages. To date, there is a lack of targeted therapies for HLH. It is validated that macrophages in HLH efficiently phagocytose anti-CD41-platelets (anti-CD41-PLTs) from immune thrombocytopenia (ITP) patients in previous research. Hence, the pathological mechanisms of ITP are mimicked and anti-CD41-PLTs are utilized to load the macrophage-toxic drug VP16 to construct macrophage-targetable engineered platelets anti-CD41-PLT-VP16, which is a novel targeted therapy against HLH. Both in vitro and in vivo studies demonstrate that anti-CD41-PLT-VP16 has excellent targeting and pro-macrophage apoptotic effects. In HLH model mice, anti-CD41-PLT-VP16 prevents hemophagocytosis and inhibits the cytokine storm. Mechanistic studies reveal that anti-CD41-PLT-VP16 increases the cytotoxicity of VP16, facilitating precise intervention in macrophages. Furthermore, it operates as a strategic "besieger" in diminishing hyperinflammation syndrome, which can indirectly prevent the abnormal activation of T cells and NK cells and reduce the Ab-dependent cell-mediated cytotoxicity effect. The first platelet-based clinical trial is ongoing. The results show that after treatment with anti-CD41-PLT-VP16, HLH patients have a threefold increase in the overall response rate compared to patients receiving conventional chemotherapy. In conclusion, anti-CD41-PLT-VP16 provides a general insight into hyperinflammation syndrome and offers a novel clinical therapeutic strategy for HLH.

Wound healing: insights into autoimmunity, ageing, and cancer ecosystems through inflammation and IL-6 modulation

Wound healing represents a complex and evolutionarily conserved process across vertebrates, encompassing a series of life-rescuing events. The healing process runs in three main phases: inflammation, proliferation, and maturation/remodelling. While acute inflammation is indispensable for cleansing the wound, removing infection, and eliminating dead tissue characterised by the prevalence of neutrophils, the proliferation phase is characterised by transition into the inflammatory cell profile, shifting towards the prevalence of macrophages. The proliferation phase involves development of granulation tissue, comprising fibroblasts, activated myofibroblasts, and inflammatory and endothelial cells. Communication among these cellular components occurs through intercellular contacts, extracellular matrix secretion, as well as paracrine production of bioactive factors and proteolytic enzymes. The proliferation phase of healing is intricately regulated by inflammation, particularly interleukin-6. Prolonged inflammation results in dysregulations during the granulation tissue formation and may lead to the development of chronic wounds or hypertrophic/keloid scars. Notably, pathological processes such as autoimmune chronic inflammation, organ fibrosis, the tumour microenvironment, and impaired repair following viral infections notably share morphological and functional similarities with granulation tissue. Consequently, wound healing emerges as a prototype for understanding these diverse pathological processes. The prospect of gaining a comprehensive understanding of wound healing holds the potential to furnish fundamental insights into modulation of the intricate dialogue between cancer cells and non-cancer cells within the cancer ecosystem. This knowledge may pave the way for innovative approaches to cancer diagnostics, disease monitoring, and anticancer therapy.

EULAR/PReS recommendations for the diagnosis and management of Still's disease, comprising systemic juvenile idiopathic arthritis and adult-onset Still's disease

Systemic juvenile idiopathic arthritis (sJIA) and adult-onset Still's disease (AOSD) are considered the same disease, but a common approach for diagnosis and management is still missing.

METHODS

In May 2022, EULAR and PReS endorsed a proposal for a joint task force (TF) to develop recommendations for the diagnosis and management of sJIA and AOSD. The TF agreed during a first meeting to address four topics: similarity between sJIA and AOSD, diagnostic biomarkers, therapeutic targets and strategies and complications including macrophage activation syndrome (MAS). Systematic literature reviews were conducted accordingly.

RESULTS

The TF based their recommendations on four overarching principles, highlighting notably that sJIA and AOSD are one disease, to be designated by one name, Still's disease.Fourteen specific recommendations were issued. Two therapeutic targets were defined: clinically inactive disease (CID) and remission, that is, CID maintained for at least 6 months. The optimal therapeutic strategy relies on early use of interleukin (IL-1 or IL-6 inhibitors associated to short duration glucocorticoid (GC). MAS treatment should rely on high-dose GCs, IL-1 inhibitors, ciclosporin and interferon-γ inhibitors. A specific concern rose recently with cases of severe lung disease in children with Still's disease, for which T cell directed immunosuppressant are suggested. The recommendations emphasised the key role of expert centres for difficult-to-treat patients. All overarching principles and recommendations were agreed by over 80% of the TF experts with a high level of agreement.

CONCLUSION

These recommendations are the first consensus for the diagnosis and management of children and adults with Still's disease.

Chemoproteomics of Marine Natural Product Naamidine J Unveils CSE1L as a Therapeutic Target in Acute Lung Injury

Acute lung injury is a devastating illness characterized by severe inflammation mediated by aberrant activation of macrophages, resulting in significant morbidity and mortality, highlighting the urgent need for novel pharmacological targets and drug candidates. In this study, we identified a novel target for regulating inflammation in macrophages and acute lung injury via chemical proteomics and genetics based on a marine alkaloid, naamidine J (NJ). The structures of NJ-related naamidine alkaloids were first confirmed or revised by a combination of quantum chemical calculations and X-ray diffraction analysis. NJ was found as a potential anti-inflammatory agent by screening our compound library, and CSE1L was identified by chemoproteomics as a main cellular target of NJ to inhibit inflammation in macrophages and protect against acute lung injury. Mechanistically, we demonstrated that NJ directly interacted with CSE1L on the sites of His745 and Phe903 and then inhibited the nuclear translocation and transcriptional activity of transcription factor SP1, thereby suppressing inflammation in macrophages and ameliorating acute lung injury. Taken together, these findings have uncovered a novel pharmacological target for the treatment of acute lung injury and have also provided a potential druggable pocket of CSE1L and a lead compound or an available chemical tool from marine sources for investigating CSE1L function and developing novel drug candidates against acute lung injury.

Intravenous Anakinra for Treating Macrophage Activation Syndrome in Adult-Onset Still's Disease

Background

Adult-onset Still's disease (AOSD) is a rare systemic inflammatory disease characterized by fever, rash, arthritis, and multi-organ involvement. Macrophage activation syndrome (MAS), a serious complication of AOSD, poses significant diagnostic and therapeutic challenges.

Case Presentation

A 32-year-old male was diagnosed with AOSD in 2020 after being hospitalized for a fever of unknown origin and elevated liver enzymes. The patient was initially treated with corticosteroids and methotrexate but subsequently discontinued both treatment and follow-up. In September 2023, he presented with fever, sore throat, and elevated inflammatory markers. After screening for infections, methylprednisolone (MP) treatment was initiated because of AOSD activation. The following day, the patient was admitted to the intensive care unit due to an altered state of consciousness. Brain magnetic resonance imaging revealed brainstem involvement. Empirical treatments were initiated, including intravenous MP, and immunoglobulin therapy. Due to suspected macrophage activation syndrome (MAS), anakinra (ANA) infusion was initiated. Significant improvement was observed after the ANA infusion.

Conclusion

This case highlights the complex management of severe AOSD complications, emphasizing the role of early recognition, aggressive therapy, and multidisciplinary care in improving outcomes.

LEARNING POINTS

Macrophage activation syndrome (MAS) is a serious complication of adult-onset Still's disease characterized by systemic inflammation. Early recognition and prompt initiation of treatment are crucial due to the high mortality rate associated with MAS, especially when neurologic symptoms are present.Clinicians should not delay treatment pending confirmatory diagnostic tests when MAS is suspected, as early intervention can significantly impact patient outcomes.Anakinra, an interleukin-1 inhibitor, is typically administered subcutaneously but has shown promise when administered intravenously, particularly in severe cases of MAS.

Updates on CAR T cell therapy in multiple myeloma

Multiple myeloma (MM) is a hematological cancer characterized by the abnormal proliferation of plasma cells. Initial treatments often include immunomodulatory drugs (IMiDs), proteasome inhibitors (PIs), and monoclonal antibodies (mAbs). Despite salient progress in diagnosis and treatment, most MM patients typically have a median life expectancy of only four to five years after starting treatment. In recent developments, the success of chimeric antigen receptor (CAR) T-cells in treating B-cell malignancies exemplifies a new paradigm shift in advanced immunotherapy techniques with promising therapeutic outcomes. Ide-cel and cilta-cel stand as the only two FDA-approved BCMA-targeted CAR T-cells for MM patients, a recognition achieved despite extensive preclinical and clinical research efforts in this domain. Challenges remain regarding certain aspects of CAR T-cell manufacturing and administration processes, including the lack of accessibility and durability due to T-cell characteristics, along with expensive and time-consuming processes limiting health plan coverage. Moreover, MM features, such as tumor antigen heterogeneity, antigen presentation alterations, complex tumor microenvironments, and challenges in CAR-T trafficking, contribute to CAR T-cell exhaustion and subsequent therapy relapse or refractory status. Additionally, the occurrence of adverse events such as cytokine release syndrome, neurotoxicity, and on-target, off-tumor toxicities present obstacles to CAR T-cell therapies. Consequently, ongoing CAR T-cell trials are diligently addressing these challenges and barriers. In this review, we provide an overview of the effectiveness of currently available CAR T-cell treatments for MM, explore the primary resistance mechanisms to these treatments, suggest strategies for improving long-lasting remissions, and investigate the potential for combination therapies involving CAR T-cells.

Physiologically Based Pharmacokinetic Modelling in Critically Ill Children Receiving Anakinra While on Extracorporeal Life Support

BACKGROUND AND OBJECTIVE

Because of the pathophysiological changes associated with critical illness and the use of extracorporeal life support (ECLS) such as continuous renal replacement therapy (CRRT) and extracorporeal membrane oxygenation (ECMO), the pharmacokinetics of drugs are often altered. The objective of this study was to develop a physiologically based pharmacokinetic (PBPK) model for anakinra in children that accounts for the physiological changes associated with critical illness and ECLS technology to guide appropriate pharmacotherapy.

METHODS

A PBPK model for anakinra was first developed in healthy individuals prior to extrapolating to critically ill children receiving ECLS. To account for the impact of anakinra clearance by the dialysis circuit, a CRRT compartment was added to the pediatric PBPK model and parameterized using data from a previously published ex-vivo study. Additionally, an ECMO compartment was added to the whole-body structure to create the final anakinra ECLS-PBPK model. The final model structure was validated by comparing predicted concentrations with observed patient data. Due to limited information in guiding anakinra dosing in this population, in-silico dose simulations were conducted to provide baseline recommendations.

RESULTS

By accounting for changes in physiology and the addition of ECLS compartments, the final ECLS-PBPK model predicted the observed plasma concentrations in an adolescent receiving subcutaneous anakinra. Furthermore, dosing simulations suggest that anakinra exposure in adolescents receiving ECLS is similar to that in healthy counterparts.

CONCLUSION

The anakinra ECLS-PBPK model developed in this study is the first to predict plasma concentrations in a population receiving simultaneous CRRT and ECMO. Dosing simulations provided may be used to inform anakinra use in critically ill children and guide future clinical trial planning.

Hemophagocytic Lymphohistiocytosis Unmasking Systemic Lupus Erythematosus: Management With Belimumab and a Case Study

Secondary hemophagocytic lymphohistiocytosis (HLH) is a life-threatening hyperinflammatory condition caused by the hyperactivation of macrophages and T-cells, triggered by infection, malignancy, or underlying rheumatological conditions. It rarely presents as a first manifestation of a rheumatological condition. Macrophage activation syndrome (MAS) is secondary HLH associated with underlying hematological conditions. Here, we present a case of a previously healthy 29-year-old female who was admitted with fever, rash, and pancytopenia, found to have HLH, and a workup revealed underlying systemic lupus erythematosus (SLE). She was successfully treated with dexamethasone, etoposide, and belimumab, with complete recovery of her symptoms. This case highlights the importance of a thorough evaluation of rheumatological conditions in all patients with HLH despite their previous medical history and the use of belimumab for SLE.

The NLRP3 inflammasome is essential for IL-18 production in a murine model of macrophage activation syndrome

Hyperinflammatory disease is associated with an aberrant immune response resulting in cytokine storm. One such instance of hyperinflammatory disease is known as macrophage activation syndrome (MAS). The pathology of MAS can be characterised by significantly elevated serum levels of interleukin-18 (IL-18) and interferon gamma (IFNγ). Given the role for IL-18 in MAS, we sought to establish the role of inflammasomes in the disease process. Using a murine model of CpG-oligonucleotide-induced MAS, we discovered that the expression of the NLRP3 inflammasome was increased and correlated with IL-18 production. Inhibition of the NLRP3 inflammasome or the downstream caspase-1 prevented MAS-mediated upregulation of IL-18 in the plasma but, interestingly, did not alleviate key features of hyperinflammatory disease including hyperferritinaemia and splenomegaly. Furthermore blockade of IL-1 receptor with its antagonist IL-1Ra did not prevent the development of CpG-induced MAS, despite being clinically effective in the treatment of MAS. These data demonstrate that, during the development of MAS, the NLRP3 inflammasome was essential for the elevation in plasma IL-18 - a key cytokine in clinical cases of MAS - but was not a driving factor in the pathogenesis of CpG-induced MAS.

Macrophage Activation Syndrome in Children: Update on Diagnosis and Treatment

Macrophage activation syndrome (MAS) is potentially fatal; so, early diagnosis and timely treatment are essential. However, detecting MAS is sometimes challenging because its principal features can be observed in other pediatric diseases that cause severe inflammation. Cytokine storm due to immune dysregulation represents the clinical and laboratory features of MAS that are included in the diagnostic criteria. Most cases of MAS occur as an underlying condition worsens and progresses. Therefore, a patient with autoimmune or autoinflammatory disease who shows unexplained clinical deterioration despite appropriate management should be considered at high risk for MAS (i.e., occult MAS). The basic principles of treatment are control of triggering factors, supportive care, and relief of hyperinflammation. Systemic steroids and cyclosporine A are frequently used as a first-line treatment. For the treatment of refractory MAS, cytokine-specific biologic agents such as anakinra have recently become preferred over traditional immunosuppressive agents such as etoposide. MAS might be underrecognized in pediatric patients with infectious and inflammatory diseases due to its diverse clinical presentations. Clinical suspicion of MAS is of the utmost importance for early recognition of the disease.

Safety and efficacy of anakinra in hemophagocytic lymphohistiocytosis associated with acute leukemia

Not available.

Clinical course and peculiarities of Parechovirus and Enterovirus central nervous system infections in newborns: a single-center experience

Parechovirus (HpEV) and Enterovirus (EV) infections in children mostly have a mild course but are particularly fearsome in newborns in whom they may cause aseptic meningitis, encephalitis, and myocarditis. Our study aimed to describe the clinical presentations and peculiarities of CNS infection by HpEV and EV in neonates. This is a single-center retrospective study at Istituto Gaslini, Genoa, Italy. Infants aged ≤ 30 days with a CSF RTq-PCR positive for EV or HpEV from January 1, 2022, to December 1, 2023, were enrolled. Each patient's record included demographic data, blood and CSF tests, brain MRI, therapies, length of stay, ICU admission, complications, and mortality. The two groups were compared to identify any differences and similarities. Twenty-five patients (15 EV and 10 HpEV) with a median age of 15 days were included. EV patients had a more frequent history of prematurity/neonatal respiratory distress syndrome (p = 0.021), more respiratory symptoms on admission (p = 0.012), and higher C-reactive protein (CRP) levels (p = 0.027), whereas ferritin values were significantly increased in HpEV patients (p = 0.001). Eight patients had a pathological brain MRI, equally distributed between the two groups. Three EV patients developed myocarditis and one HpEV necrotizing enterocolitis with HLH-like. No deaths occurred.  Conclusion: EV and HpEV CNS infections are not easily distinguishable by clinical features. In both cases, brain MRI abnormalities are not uncommon, and a severe course of the disease is possible. Hyper-ferritinemia may represent an additional diagnostic clue for HpEV infection, and its monitoring is recommended to intercept HLH early and initiate immunomodulatory treatment. Larger studies are needed to confirm our findings. What is Known: • Parechovirus and Enteroviruses are the most common viral pathogens responsible for sepsis and meningoencephalitis in neonates and young infants. • The clinical course and distinguishing features of Parechovirus and Enterovirus central nervous system infections are not well described. What is New: • Severe disease course, brain MRI abnormalities, and complications are not uncommon in newborns with Parechovirus and Enteroviruses central nervous system infections. • Hyper-ferritinemia may represent an additional diagnostic clue for Parechovirus infection and its monitoring is recommended.

[Hemophagocytic lymphohistiocytosis and macrophage activation syndrome : A multidisciplinary challenge]

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening hyperinflammatory syndrome that is characterized by hyperferritinemia, cytopenia, disseminated intravascular coagulopathy and functional disorders of the liver and the central nervous system. The term macrophage activation syndrome is predominantly used for secondary HLH in the context of autoimmune diseases (e.g., systemic juvenile idiopathic arthritis). In addition, malignancies and genetic inborn errors of immunity can predispose to the development of HLH. Infections (e.g., Epstein-Barr virus) in turn represent possible triggers of an acute episode. Due to the unspecific manifestation of the disease, a systematic evaluation of the organ systems is recommended in the clinical and laboratory analytical clarification of hyperinflammatory syndromes. In general, the treatment should be carried out by a multidisciplinary team with expertise in rheumatology, hematological oncology, infectious diseases and intensive care medicine. The primary treatment of HLH usually consists of glucocorticoids and in cases of a rapid deterioration of the condition anakinra (interleukin 1 block) and intravenous immunoglobulins can be employed. Treatment of the underlying disease should be consequently carried out in parallel, together with antimicrobial treatment.

Intravenous high-dose anakinra drops venous thrombosis and acute coronary syndrome in severe and critical COVID-19 patients: a propensity score matched study

In our study, we aimed to evaluate the effect of high-dose intravenous anakinra treatment on the development of thrombotic events in severe and critical COVID-19 patients. This retrospective observational study was conducted at a tertiary referral center in Aksaray, Turkey. The study population consisted of two groups as follows; the patients receiving high-dose intravenous anakinra (anakinra group) added to background therapy and the patients treated with standard of care (SoC) as a historical control group. Age, gender, mcHIS scores, and comorbidities such as diabetes mellitus, hypertension, and coronary heart disease of the patients were determined as the variables to be matched. We included 114 patients in SoC and 139 patients in the Anakinra group in the study. Development of any thromboembolic event (5% vs 12.3%, p = 0.038; OR 4.3) and PTE (2.9% vs 9.6%, p = 0.023; OR 5.1) were lower in the Anakinra group than SoC. No patient experienced cerebrovascular accident and/or clinically evident deep venous thrombosis both in two arms. After 1:1 PS matching, 88 patients in SoC and 88 patients in the Anakinra group were matched and included in the analysis. In survival analysis, the development of any thromboembolic event, pulmonary thromboembolism, and acute coronary syndrome (ACS) were higher in SoC compared to Anakinra. Survival rate was also lower in patients with SoC arm than Anakinra in patients who had any thromboembolic event as well as ACS. In our study, the development of thrombosis was associated with hyperinflammation in patients with severe and critical COVID-19. Intravenous high-dose anakinra treatment decreases both venous and arterial events in patients with severe and critical COVID-19.

Case report: Rapid resolution of grade IV ICANS after first line intrathecal chemotherapy with methotrexate, cytarabine and dexamethasone

Corticosteroid therapy is the mainstay of immune effector cell-associated neurotoxicity syndrome (ICANS) management, although its use has been associated with worse overall survival (OS) and progression-free survival (PFS) after chimeric antigen receptor T-cell (CAR-T cell) therapy. Many options are being investigated for prophylaxis and management. Accumulating evidence supports the use of intrathecal (IT) chemotherapy for the management of high-grade ICANS. Here, we describe a case of a patient with stage IV Primary mediastinal B-cell lymphoma (PMBCL) successfully treated with IT methotrexate, cytarabine, and dexamethasone as first-line therapy for CD19 CAR-T cell-associated grade IV ICANS. The stable and rapid resolution of ICANS to grade 0 allowed us to discontinue systemic corticosteroid use, avoiding CAR-T cells ablation and ensuring preservation of CAR-T cell function. The described patient achieved a complete radiologic and clinical response to CD19 CAR-T cell therapy and remains disease-free after 9 months. This case demonstrates a promising example of how IT chemotherapy could be used as first-line treatment for the management of high-grade ICANS.

Heterogeneity of macrophage activation syndrome and treatment progression

Macrophage activation syndrome (MAS) is a rare complication of autoimmune inflammatory rheumatic diseases (AIIRD) characterized by a progressive and life-threatening condition with features including cytokine storm and hemophagocytosis. Predisposing factors are typically associated with microbial infections, genetic factors (distinct from typical genetically related hemophagocytic lymphohistiocytosis (HLH)), and inappropriate immune system overactivation. Clinical features include unremitting fever, generalized rash, hepatosplenomegaly, lymphadenopathy, anemia, worsening liver function, and neurological involvement. MAS can occur in various AIIRDs, including but not limited to systemic juvenile idiopathic arthritis (sJIA), adult-onset Still's disease (AOSD), systemic lupus erythematosus (SLE), Kawasaki disease (KD), juvenile dermatomyositis (JDM), rheumatoid arthritis (RA), and Sjögren's syndrome (SS), etc. Although progress has been made in understanding the pathogenesis and treatment of MAS, it is important to recognize the differences between different diseases and the various treatment options available. This article summarizes the cell types and cytokines involved in MAS-related diseases, the heterogeneity, and treatment options, while also comparing it to genetically related HLH.

Cytokine Storm Syndrome Responsive to IL-1 Inhibition in Trisomy 21

Background

Cytokine storm syndromes (CSS) are life-threatening systemic inflammatory disorders caused by immune system dysregulation. They can lead to organ failure and are triggered by various factors, including infections, malignancy, inborn errors of immunity, and autoimmune conditions. Trisomy 21 (TS21), also known as Down syndrome, is a genetic disorder associated with immune dysfunction, increased infection susceptibility, and inflammation. While TS21 has been linked to infectious-triggered hyperinflammation, its role as a primary cause of CSS has not been confirmed. Case Presentation. We present a case of a 16-year-old male with TS21 with fever, rash, joint pain, and abdominal symptoms. Extensive investigations ruled out infections, autoimmune conditions, malignancies, and inborn errors of immunity as triggers for a CSS. The patient's symptoms improved with treatment using IL-1 inhibition and corticosteroids.

Conclusions

This case reinforces that TS21 is an immune dysregulation disorder and highlights the importance of considering CSS in TS21 patients, even when triggers are unclear. The positive response to IL-1 inhibition in this patient suggests that dysregulation of the IL-1 superfamily and the NLRP3 inflammasome may contribute to CSS in TS21. This finding raises the possibility of using IL-1 inhibition as a treatment approach for CSS in TS21 patients.

Use of high-dose steroid therapy: addition of anakinra in the treatment of severe COVID-19

OBJECTIVE

The aim of this study was to compare the clinical effects of the addition of anakinra to high-dose steroid therapy in COVID-19 patients with macrophage activation syndrome.

METHODS

This was a single-center retrospective study conducted in Ümraniye Training and Research Hospital between March 11, 2020, and April 28, 2021. Patients receiving only high-dose steroid or anakinra+steroid were enrolled. The first day of anakinra was considered as day 0. Laboratory values and oxygen requirements were followed up for 7 days. Patients were divided into two groups: 66 patients in the high-dose steroid group and 67 patients in the anakinra+steroid group. The primary outcome was 28-day mortality.

RESULTS

After treatment, a significant decrease in ferritin levels was detected only in the anakinra+steroid group (p=0.001). In both groups, there were significant changes in lymphocytes, C-reactive protein, lactate dehydrogenase, and fibrinogen levels during the 7-day follow-up. Changes in oxygen status according to the World Health Organization clinical scale on day 3 and day 7 between high-dose steroid and anakinra+steroid groups were similar (p=0.976). Complications were higher in the anakinra+steroid group than in the steroid group (26% vs. 12%, p=0.03). The rates of 28-day mortality were 57% in the anakinra+steroid group and 42% in the high-dose steroid group (p=0.48). In multivariate regression, anakinra did not affect 28-day mortality (p=0.67).

CONCLUSION

The addition of anakinra to steroid treatment resulted in a significant decrease in biochemical parameters. However, no significant difference was observed in the oxygen status between the groups. The addition of anakinra to steroid treatment did not decrease mortality. Clinicians should be aware of the complications of anti-inflammatory therapies.

Combination therapy of high-dose intravenous anakinra and baricitinib in patients with critical COVID-19: Promising results from retrospective observational study

INTRODUCTION

In this study, we aimed to evaluate the safety and efficacy of combination treatment of high-dose intravenous anakinra and baricitinib in patients with critically ill COVID-19.

MATERIAL AND METHODS

This retrospective observational study was conducted in a tertiary center with diagnosis of COVID-19 patients.Study population consisted of patients with positive polymerase chain reaction and computer tomography findings compatible with COVID-19 as well as critical illness.

RESULTS

Data of 15 patients in combination group and 43 patients in control group were evaluated and included into the study. Overall mortality was 46.7 % (n = 7) in combination arm and 69.8 % (n = 30) in control group although it was not statistically significant (p = 0.1). Similarly, need of intubation was also lower in combination arm (46.7 %) compared to control group (69.8 %), it was not significantly different (p = 0.1). ICU admission was significantly lower in combination (46.7 %, n = 7) arm than control group (76.7 %, n = 33) (p = 0.03, Odds ratio [OR]:4.7). Development of severe infection (20 %, n = 3 vs 25 %, n = 9/36), pulmonary embolism (6.7 %, n = 1 vs 0), myocardial infarction (6.7 %, n = 1 vs 2.6 %, n = 1/38) and pneumothorax (13.3 %, n = 2 vs 2.6 %, n = 1/38) were not different between two groups (p = 0.7, p = 0.3, p = 0.5 and p = 0.2). In multivariable analysis only cHIS score was associated with high mortality (p = 0.018, OR:2.8, [95 % confidence interval: 1.2-6.6]). In survival analysis, mortality rate was significantly lower in combination arm than control group (Log-Rank:p = 0.04).

CONCLUSION

Combination therapy of high-dose anakinra and baricitinib may be an adequate treatment option in patients with COVID-19 who had critical disease and has acceptable safety profile.

Toxicities, intensive care management, and outcome of chimeric antigen receptor T cells in adults: an update

BACKGROUND

Chimeric antigen receptor T cells are a promising new immunotherapy for haematological malignancies. Six CAR-T cells products are currently available for adult patients with refractory or relapsed high-grade B cell malignancies, but they are associated with severe life-threatening toxicities and side effects that may require admission to ICU.

OBJECTIVE

The aim of this short pragmatic review is to synthesize for intensivists the knowledge on CAR-T cell therapy with emphasis on CAR-T cell-induced toxicities and ICU management of complications according to international recommendations, outcomes and future issues.

Does your unwell patient have haemophagocytic lymphohistiocytosis?

Haemophagocytic lymphohistiocytosis is a severe systemic hyperinflammatory syndrome characterised by dysregulation of immune cells and excessive production of cytokines, also known as a cytokine storm. It has distinctive clinical features with fever, hyperferritinaemia and falling blood counts. In adults, this usually occurs secondary to an underlying driver or trigger including infection, malignancy or rheumatic diseases. Prompt treatment with immunomodulatory therapy, including corticosteroids and the recombinant IL-1 receptor antagonist anakinra, is recommended to switch off the cytokine storm. Etoposide-based regimens are sometimes needed, and newer therapies such as emapalumab and JAK inhibitors are increasingly being used. The incidence of haemophagocytic lymphohistiocytosis has increased significantly over the last 20 years which may partly reflect increased awareness of the condition. Although relatively rare, haemophagocytic lymphohistiocytosis can be encountered by a broad range of hospital physicians, so knowing how to diagnose and treat this condition is essential. This article reviews the pathogenesis, clinical features, causes, diagnosis and treatment of haemophagocytic lymphohistiocytosis to improve physician recognition and management of this condition to improve future patient outcomes.

The NLRP3 inflammasome is essential for IL-18 production in a murine model of macrophage activation syndrome

Hyperinflammatory disease is associated with an aberrant immune response resulting in cytokine storm. One such instance of hyperinflammatory disease is known as macrophage activation syndrome (MAS). The pathology of MAS can be characterised by significantly elevated serum levels of interleukin (IL)-18 and interferon (IFN)-γ. Given the role for IL-18 in MAS, we sought to establish the role of inflammasomes in the disease process. Using a murine model of CpG-DNA induced MAS, we discovered that the expression of the NLRP3 inflammasome was increased and correlated with IL-18 production. Inhibition of the NLRP3 inflammasome, or downstream caspase-1, prevented MAS-mediated upregulation of plasma IL-18 but interestingly did not alleviate key features of hyperinflammatory disease including hyperferritinaemia and splenomegaly. Furthermore IL-1 receptor blockade with IL-1Ra did not prevent the development of CpG-induced MAS, despite being clinically effective in the treatment of MAS. These data demonstrate that in the development of MAS, the NLRP3 inflammasome was essential for the elevation in plasma IL-18, a key cytokine in clinical cases of MAS, but was not a driving factor in the pathogenesis of CpG-induced MAS.

Unveiling the Mystery of Adult-Onset Still's Disease: A Compelling Case Report

Adult-onset Still's disease (AOSD) is a rare systemic inflammatory disorder. Diagnosis can take a long time, especially in the presence of confounding factors, and it is, to some extent, a process of exclusion. AOSD has life-threating complications ranging from asymptomatic to severe, such as macrophage activation syndrome (MAS), which is also referred to as hemophagocytic lymphohistocytosis (HLH). This condition is correlated with cytokine storm production and monocyte/macrophage overactivation and typically occurs with rash, pyrexia, pancytopenia, hepatosplenomegaly and systemic involvement. Exitus occurs in approximately 10% of cases. For the treatment of MAS-HLH, the Histiocyte Society currently suggests high-dose corticosteroids, with the possible addition of cyclosporine A, anti-interleukin (IL)-1, or IL-6 biological drugs; the inclusion of etoposide is recommended for the most severe conditions. In all cases, a multidisciplinary collaboration involving the resources and expertise of several specialists (e.g., rheumatologist, infectiologist, critical care medicine specialist) is advised. Herein, we provide a detailed description of the clinical case of a previously healthy young woman in which MAS developed as a dramatic onset manifestation of AOSD and whose diagnosis posed a real clinical challenge; the condition was finally resolved by applying the HLH-94 protocol (i.e., etoposide in combination with dexamethasone).

Case Report: Refractory macrophage activation syndrome requiring high-dose anakinra, emapalumab, and etoposide therapy in early-onset systemic juvenile idiopathic arthritis associated with adenoviremia

Macrophage activation syndrome (MAS) is a life-threatening condition characterized by the excessive stimulation of macrophages and T lymphocytes, provoked by infections, malignancy, and autoimmune or autoinflammatory conditions such as systemic juvenile idiopathic arthritis (sJIA). Clinical signs of sJIA may include high-spiking, quotidian fevers, lymphadenopathy, hepatosplenomegaly, and a salmon-colored migratory, evanescent rash. By contrast, MAS is characterized by unremitting fevers and diffuse, fixed, maculopapular rashes. In addition to hepatosplenomegaly and lymphadenopathy, patients with MAS may also have clinical signs of coagulopathy, as well as cardiac, lung, renal, and central nervous system dysfunction. The empiric treatment for MAS is initially high-dose IV corticosteroids, but usually requires addition of immunomodulators such as tacrolimus or a biologic such as Anakinra to control. The addition of immunotherapies for MAS has improved patient outcomes. We present a 2-year-old male patient with a history of early-onset sJIA, who presented with MAS refractory to corticosteroids and anakinra triggered by adenoviremia that required addition of emapalumab to control. We believe this is the first reported case of a combination of immunosuppressive therapy of emapalumab, etoposide, anakinra, tacrolimus, and corticosteroids used in the successful treatment of infection-induced MAS in early-onset sJIA. Given the lack of treatment guidelines and approved therapies for MAS, alternative strategies should be considered for patients with an intractable course.

CD8+ T Cell Biology in Cytokine Storm Syndromes

Familial forms of hemophagocytic lymphohistiocytosis (HLH) are caused by loss-of-function mutations in genes encoding perforin as well as those required for release of perforin-containing cytotoxic granule constituent. Perforin is expressed by subsets of CD8+ T cells and NK cells, representing lymphocytes that share mechanism of target cell killing yet display distinct modes of target cell recognition. Here, we highlight recent findings concerning the genetics of familial HLH that implicate CD8+ T cells in the pathogenesis of HLH and discuss mechanistic insights from animal models as well as patients that reveal how CD8+ T cells may contribute to or drive disease, at least in part through release of IFN-γ. Intriguingly, CD8+ T cells and NK cells may act differentially in severe hyperinflammatory diseases such as HLH. We also discuss how CD8+ T cells may promote or drive pathology in other cytokine release syndromes (CSS). Moreover, we review the molecular mechanisms underpinning CD8+ T cell-mediated lymphocyte cytotoxicity, key to the development of familial HLH. Together, recent insights to the pathophysiology of CSS in general and HLH in particular are providing promising new therapeutic targets.

Cytokine storm in COVID-19 and malaria: Annals of pro-inflammatory cytokines

Infectious diseases are affecting the people worldwide. Mostly, infectious agents activate excessive production of cytokines so called cytokine storm. Among the infectious diseases COVID-19 is one of the deadliest diseases affecting individuals all over the world, moreover, Plasmodium falciparum malaria and HIV are major killers. An excessive pro-inflammatory response is one of the major causes of pathological conditions in these diseases. It is important to investigate the pathophysiology in the infectious diseases such as COVID-19, malaria and HIV as there is no concrete therapy against them so far. Exploration of excessive pro-inflammation could be important for therapeutic intervention. In this article, an attempt has been made to analyze the pathological conditions arise due to excessive inflammatory response in COVID-19, malaria and other infectious diseases. Targeting excessive pro-inflammatory response/cytokine storm in infectious diseases could be a useful strategy.

IL-1 Family Blockade in Cytokine Storm Syndromes

Interleukin-1 is a prototypic proinflammatory cytokine that is elevated in cytokine storm syndromes (CSSs), such as secondary hemophagocytic lymphohistiocytosis (sHLH) and macrophage activation syndrome (MAS). IL-1 has many pleotropic and redundant roles in both innate and adaptive immune responses. Blockade of IL-1 with recombinant human interleukin-1 receptor antagonist has shown efficacy in treating CSS. Recently, an IL-1 family member, IL-18, has been demonstrated to be contributory to CSS in autoinflammatory conditions, such as in inflammasomopathies (e.g., NLRC4 mutations). Anecdotally, recombinant IL-18 binding protein can be of benefit in treating IL-18-driven CSS. Lastly, another IL-1 family member, IL-33, has been postulated to contribute to CSS in an animal model of disease. Targeting of IL-1 and related cytokines holds promise in treating a variety of CSS.

Cytokine Storm and Sepsis-Induced Multiple Organ Dysfunction Syndrome

There is extensive overlap of clinical features among familial or primary HLH (pHLH), reactive or secondary hemophagocytic lymphohistiocytosis (sHLH) [including macrophage activation syndrome (MAS) related to rheumatic diseases], and hyperferritinemic sepsis-induced multiple organ dysfunction syndrome (MODS); however, the distinctive pathobiology that causes hyperinflammatory process in each condition requires careful considerations for therapeutic decision-making. pHLH is defined by five or more of eight HLH-2004 criteria [1], where genetic impairment of natural killer (NK) cells or CD8+ cytolytic T cells results in interferon gamma (IFN-γ)-induced hyperinflammation regardless of triggering factors. Cytolytic treatments (e.g., etoposide) or anti-IFN-γ monoclonal antibody (emapalumab) has been effectively used to bridge the affected patients to hematopoietic stem cell transplant. Secondary forms of HLH also have normal NK cell number with decreased cytolytic function of varying degrees depending on the underlying and triggering factors. Although etoposide was uniformly used in sHLH/MAS in the past, the treatment strategy in different types of sHLH/MAS is increasingly streamlined to reflect the triggering/predisposing conditions, severity/progression, and comorbidities. Accordingly, in hyperferritinemic sepsis, the combination of hepatobiliary dysfunction (HBD) and disseminated intravascular coagulation (DIC) reflects reticuloendothelial system dysfunction and defines sepsis-associated MAS. It is demonstrated that as the innate immune response to infectious organism prolongs, it results in reduction in T cells and NK cells with subsequent lymphopenia even though normal cytolytic activity continues (Figs. 30.1, 30.2, 30.3, and 30.4). These changes allow free hemoglobin and pathogens to stimulate inflammasome activation in the absence of interferon-γ (IFN-γ) production that often responds to source control, intravenous immunoglobulin (IVIg), plasma exchange, and interleukin 1 receptor antagonist (IL-1Ra), similar to non-EBV, infection-induced HLH.

Hemophagocytic Lymphohistiocytosis in Adolescents and Young Adults: Genetic Predisposition and Secondary Disease

Hemophagocytic lymphohistiocytosis (HLH) is a disorder of impaired immune regulation resulting in hyperinflammation that is ultimately fatal if not treated. HLH is categorized into familial disease, caused by genetic mutations affecting the function of cytotoxic T lymphocytes and natural killer cells, and secondary disease, triggered by infections, malignancies, rheumatologic disorders, or immune deficiency. Adolescent and young adults with HLH represent a unique population with specific diagnostic challenges. Here we review the diagnostic criteria, possible etiologies, pathophysiology, and management of HLH with focus on the adolescent population.

Iatrogenic HLH

Hemophagocytic lymphohistiocytosis (HLH) can be categorized as either primary (familial, generally occurring in infants) or secondary (sHLH, occurring at any age in association with a variety of conditions) and is mainly triggered by infections, autoimmune diseases, and malignant conditions. Our understanding of the pathophysiology of sHLH is still evolving, and among the causes and associations with the syndrome, those putatively associated with iatrogenic causes remain among the most poorly understood due to the rarity of these entities and the multiple confounders so often present in the patients in whom they are reported. Herein, we present a review of the literature to describe the diagnostic and therapeutic challenges of sHLH associated with iatrogenic causes and discuss some of the challenges and future directions in our efforts to better understand these complex conditions for the advancement of patient outcomes.

Systemic Lupus Erythematosus and Cytokine Storm

Systemic lupus erythematosus (SLE) is the prototype of autoimmune diseases and can manifest with a plethora of clinical signs and symptoms associated with a myriad of laboratory abnormalities. An infrequent but potentially lethal complication of SLE is macrophage activation syndrome (MAS). The diagnosis of MAS in SLE can be very challenging due to similarities in presentation of both flares and infections, such as fever, lymphadenopathy, splenomegaly, and cytopenias. These aggravating factors contribute to the increased risk of poor outcomes in SLE-associated MAS. Indeed, at the moment MAS remains invariably lethal if untreated and still has a high mortality rate with treatment. In this chapter, we discuss several aspects of MAS in the context of SLE and in particular, the pathogenesis of MAS in SLE, how MAS presents in pediatric versus adult SLE, and, finally, MAS treatment in SLE and future directions.

Anakinra Removal by Continuous Renal Replacement Therapy: An Ex Vivo Analysis

OBJECTIVES

Patients with sepsis are at significant risk for multiple organ dysfunction, including the lungs and kidneys. To manage the morbidity associated with kidney impairment, continuous renal replacement therapy (CRRT) may be required. The extent of anakinra pharmacokinetics in CRRT remains unknown. The objectives of this study were to investigate the anakinra-circuit interaction and quantify the rate of removal from plasma.

DESIGN

The anakinra-circuit interaction was evaluated using a closed-loop ex vivo CRRT circuit. CRRT was performed in three phases based on the method of solute removal: 1) hemofiltration, 2) hemodialysis, and 3) hemodiafiltration. Standard control samples of anakinra were included to assess drug degradation.

SETTING

University research laboratory.

PATIENTS

None.

INTERVENTIONS

Anakinra was administered to the CRRT circuit and serial prefilter blood samples were collected along with time-matched control and hemofiltrate samples. Each circuit was run in triplicate to assess inter-run variability. Concentrations of anakinra in each reference fluid were measured by enzyme-linked immunosorbent assay. Transmembrane filter clearance was estimated by the product of the sieving coefficient/dialysate saturation constant and circuit flow rates.

MEASUREMENTS AND MAIN RESULTS

Removal of anakinra from plasma occurred within minutes for each CRRT modality. Average drug remaining (%) in plasma following anakinra administration was lowest with hemodiafiltration (34.9%). The average sieving coefficient was 0.34, 0.37, and 0.41 for hemodiafiltration, hemofiltration, and hemodialysis, respectively. Transmembrane clearance was fairly consistent across each modality with the highest during hemodialysis (5.53 mL/min), followed by hemodiafiltration (4.99 mL/min), and hemofiltration (3.94 mL/min). Percent drug remaining within the control samples (93.1%) remained consistent across each experiment, indicating negligible degradation within the blood.

CONCLUSIONS

The results of this analysis are the first to demonstrate that large molecule therapeutic proteins such as anakinra, are removed from plasma with modern CRRT technology. Current dosing recommendations for patients with severe renal impairment may result in subtherapeutic anakinra concentrations in those receiving CRRT.

High-dose anakinra in addition to standard of care including corticosteroids in patients with severe COVID-19 treated with non-invasive ventilation

Management of COVID-19 patients experiencing persisting respiratory failure despite corticosteroids remains challenging. Data on high-dose intravenous anakinra (HD-ANK) in this context are lacking. We aimed to investigate the impact of HD-ANK on mortality in COVID-19 patients progressing to non-invasive ventilation (NIV) while receiving corticosteroids. We retrospectively analyzed the impact of HD-ANK on 28-day mortality in individuals hospitalized with COVID-19 necessitating NIV after corticosteroid initiation. A total of 256 patients were identified: 146 received standard-of-care only (SOC), and 110 received HD-ANK+SOC. The groups were well-balanced at baseline. In-hospital mortality at 28 days did not differ between the two groups. HD-ANK is not beneficial in patients with severe COVID-19 deteriorating despite corticosteroids.

Immune Effector Cell-Associated HLH-like Syndrome: A Review of the Literature of an Increasingly Recognized Entity

Since CAR-T cell therapy was initially approved in 2017, its use has become more prevalent and so have its side effects. CAR-T-related HLH, also named immune effector cell-associated HLH-like syndrome (IEC-HS), is a rare but fatal toxicity if not recognized promptly. We conducted a review of the literature in order to understand the prevalence of IEC-HS as well as clarify the evolution of the diagnostic criteria and treatment recommendations. IEC-HS occurrence varies between CAR-T cell products and the type of malignancy treated. Diagnosis can be challenging as there are no standardized diagnostic criteria, and its clinical features can overlap with cytokine release syndrome and active hematological disease. Suggested treatment strategies have been extrapolated from prior experience in HLH and include anakinra, corticosteroids and ruxolitinib. IEC-HS is a potentially fatal toxicity associated with CAR-T cell therapy. Early recognition with reliable diagnostic criteria and prompt implementation of treatment specific to IEC-HS is imperative for improving patient outcomes.

Febrile infection-related epilepsy syndrome in childhood: A clinical review and practical approach

Febrile infection-related epilepsy syndrome (FIRES) of unknown aetiology is an extremely rare but severe epilepsy syndrome. It is characterized by a nonspecific febrile infection a few days before the onset of super-refractory status epilepticus, followed by refractory epilepsy and high morbidity in previously healthy children and young adults. To date, FIRES is incurable and irreversible. The clinical course may depend more on time than on therapy, while the outcome may depend more on the clinical spectrum than on therapy. Based on a literature search, retrospective data analysis, and personal observations, this review aimed to explore the clinical spectrum and therapeutic options for FIRES to improve outcomes by optimized and more standardized diagnosis and therapy, including adapted immunotherapy and a less aggressive approach to manage seizures, as seizure-freeness is difficult to achieve and, therefore, not the primary goal for cryptogenic FIRES.

Distinct roles of IL-18 and IL-1β in murine model of macrophage activation syndrome

BACKGROUND

IL-18 and IL-1β play a central role in the pathogenesis of systemic juvenile idiopathic arthritis and its life-threatening complication, macrophage activation syndrome (MAS).

OBJECTIVES

This study aimed to clarify the role of IL-18 and IL-1β in the pathogenesis of MAS.

METHODS

We developed a mouse model to evaluate the role of each cytokine with Toll-like receptor 9 stimulation after continuous infusion with IL-18, IL-1β, and a combination of both for 7 days. The symptoms and laboratory findings were compared among the IL-18, IL-1β, and combination (IL-18+IL-1β) groups.

RESULTS

Body weight was significantly decreased in the IL-1β and combination groups. Splenomegaly was observed in all groups, whereas hepatomegaly was noted in the IL-18 group only. Decreased T-cell numbers, anemia, and thrombocytopenia were observed in the combination group. IFN-γ, CXCL9, and IL-12A mRNA levels were upregulated and IL-10 mRNA levels in the spleen were downregulated in the IL-18 group. Hepatomegaly and splenomegaly in the IL-18 group were observed in a dose-dependent manner. TNF-α, CXCL9, and IL-12A mRNA levels were upregulated only in those mice with extremely elevated plasma IL-18 levels.

CONCLUSION

IL-18 and IL-1β have distinct roles in the pathogenesis of MAS. Dual blockade of IL-18 and IL-1β might be necessary to treat MAS.

IFN-α induced systemic lupus erythematosus complicated with hemophagocytic lymphohistiocytosis: a case report and literature review

Hemophagocytic lymphohistiocytosis (HLH) is a severe and life-threatening hyperinflammatory condition characterized by excessive activation of macrophages and T cells and resulted in multi-organ dysfunction. HLH can be a primary disease or secondary to infections, malignancy, and some autoimmune diseases, including adult-onset Still's disease (AOSD) and systemic lupus erythematosus (SLE). However, it is rare for HLH to occur as a secondary condition to drug-induced lupus erythematosus (DILE). In this report, we present a case of HLH as an unusual complication during SLE treatment in a 31-year-old male patient. The patient initially suffered from active chronic hepatitis B (CHB) and was treated with pegylated INFα-2b (Peg-INFα-2b), tenofovir disoproxil and lamivudine. After 19 months, CHB obtained biochemical and virological response with HBsAg positive to HBsAb. The patient developed fever, headache, and cytopenia after Peg-INFα-2b treatment for 33 months, and laboratory studies revealed that ANA and anti dsDNA were positive. He displayed 5 features meeting the HLH-2004 criteria for diagnosis including fever, pancytopenia, hyperferritinemia, high levels of soluble CD25, and hemophagocytosis on bone marrow biopsy. The patient was initiated with a combination treatment of intravenous methylprednisolone pulse therapy, oral cyclosporine, and etoposide (VP-16), which was followed by a course of oral prednisolone, intravenous cyclophosphamide pulse therapy, and entecavir with complete response. To our knowledge, this is the first report of IFN-α induced SLE complicating with HLH. Physicians should consider the potential autoimmune side effects of IFN-α therapy and be alert to insidious HLH in patients diagnosed with SLE.