Macrophage Activation Syndrome and Secondary Hemophagocytic Lymphohistiocytosis in Childhood Inflammatory Disorders: Diagnosis and Management

Mortality in children and adolescents with autoimmune inflammatory rheumatic diseases admitted to the pediatric intensive care unit

BACKGROUND

This study aimed to describe the characteristics and outcomes of children and adolescents with autoimmune inflammatory rheumatic diseases (AIIRD) who were admitted to the pediatric intensive care unit (PICU). The accuracy of the Pediatric Risk of Mortality (PRISM) III and Pediatric Index of Mortality (PIM) 3 scores to predict the mortality were investigated.

METHODS

This was a retrospective cohort study. Children and adolescents with AIIRD aged ≤ 18 years who were admitted to the PICU at the largest university-based referral center in Thailand during July 2011 to June 2021 were included.

RESULTS

There were 122 PICU admissions from 74 patients; mean age of 12.0 ± 4.3 years, 74.3% female. Majority of AIIRD were systemic lupus erythematosus (SLE) (83.8%), followed by systemic juvenile idiopathic arthritis (5.4%), juvenile dermatomyositis (JDM) (2.7%) and microscopic polyangiitis (2.7%). The main cause of admission was combined infection and disease flare (29.5%). Pneumonia was the main site of infection. Acinetobacter baumanii was the most common causative agent. Macrophage activation syndrome occurred in 8 (6.5%) admissions. The mortality rate of PICU admissions was 14.8% from 18 deaths; 17 with SLE and 1 with JDM. Mechanical ventilation (aOR 24.07, 95%CI:1.33-434.91, P= 0.031), pneumothorax (aOR 24.08, 95%CI:1.76-328.86, P = 0.017 and thrombocytopenia (aOR 8.34, 95%CI:1.31-53.73, P = 0.025) were associated with mortality. The risk of mortality rate as predicted by the PRISM III score increased with a score ≥ 9. For the PIM 3 score, the risk of mortality increased if the score ≥ 3. The area under the ROC curve for the PRISM III and PIM 3 scores was 0.741 (95%CI: 0.633-0.849), P = 0.001 and 0.804 (95%CI: 0.685-0.924), P < 0.001, respectively. The model calibration using the Hosmer-Lemeshow goodness of fit test demonstrated a chi-square of 4.335, P = 0.826 for PRISM III and 7.987, P = 0.435 for PIM 3.

CONCLUSION

SLE was the main AIIRD that required admission to the PICU. Mechanical ventilation, pneumothorax and thrombocytopenia were associated with mortality in pediatric patients with AIIRD. The PRISM III and PIM 3 scores demonstrated good calibration, while the PIM 3 score provided better discrimination ability in the prediction of mortality for pediatric AIIRD.

Brucella bloodstream infection mimicking systemic juvenile idiopathic arthritis: a pediatric case report

BACKGROUND

Systemic juvenile idiopathic arthritis (sJIA) accompanied with Brucella bloodstream and bone marrow infection is an exceedingly rare occurrence in clinical practice. Owing to the striking similarity in their clinical presentations, there is a propensity for misdiagnosis or underdiagnosis.

CASE PRESENTATION

In this case, the pediatric patient underwent medical treatment across five different hospitals over a three-month period before receiving an accurate diagnosis and successful treatment. There are two primary factors contributing to this consequence. To begin with, Brucella exhibits slow growth, leading to initial blood cultures producing false negative results due to insufficient cultivation time. Additionally, sJIA and brucellosis present extremely similar clinical symptoms. In addition to arthritis, the child presented with a non-fixed erythematous rash that gradually resolved after fever subsided and was associated with increased IL-6 levels. Furthermore, both blood and bone marrow cultures displayed positive results after four days, and Brucella was identified through MALDI-TOF mass spectrometry. Combined with additional laboratory results and clinical symptoms, sJIA accompanied with Brucella bloodstream infection was ultimately diagnosed and effectively managed in our hospital.

CONCLUSION

It is crucial to emphasize that in cases of brucellosis infection, the identification of sJIA and brucellosis is of vital significance. Brucella can be isolated and cultured from blood and bone marrow within approximately two weeks, serving as the definitive indicator for diagnosing Brucella bloodstream infection. By reporting this case, we aim to share clinical experience, provide a more accurate and expedited diagnosis, as well as treatment for future patients encountering similar circumstances.

Aggressive T-cell Lymphoma Smoldering As Hemophagocytic Lymphohistiocytosis: A Diagnostic and Medical Challenge

Hemophagocytic lymphohistiocytosis (HLH) is an aggressive hematologic disease based on widespread immune activation and tissue destruction. This uncommon condition can be primary as well as secondary to infection or malignancy. However, HLH diagnosis rarely contributes to unveiling an underlying malignancy. The most crucial prognostic factor of HLH is timely diagnosis and treatment. However, due to the rarity of this syndrome and the variable clinical presentations, HLH is often underdiagnosed. A 12-year-old boy complained of recurrent fever and fatigue for the past four months. He presented with pancytopenia, hyperferritinemia, hypertriglyceridemia, elevated liver enzymes, and a severe inflammatory profile. The diagnosis of HLH disease was established. During further evaluation, a right subaxillary palpable lymph node was found. The biopsy revealed a peripheral T-cell lymphoma, not otherwise specified (PTCL, NOS). The bone marrow was also infiltrated with evidence of dissemination to the skeleton on a positron emission tomography (PET) scan (stage IV). The patient was treated with six cycles of CHOEP (cyclophosphamide, doxorubicin, oncovin, etoposide, prednisone) protocol but relapsed and passed away three months later. This case report sheds light on the importance of early recognition and treatment of HLH, as well as searching for underlying malignancy or disease, even in young patients.

Ruxolitinib-based regimen in children with autoimmune disease or autoinflammatory disease-related haemophagocytic lymphohistiocytosis

For autoimmune disease (AD) and autoinflammatory disease (AID)-related haemophagocytic lymphohistiocytosis (HLH) (AD/AID-HLH), there is still a lack of standardized treatment. Glucocorticoids (GCs) are the main treatment currently; however, 37.9% to 61% of patients fail to achieve effective control of HLH, making it urgent to find novel treatment strategies. We conducted a retrospective, single-centre study examining ruxolitinib (RUX)-based regimen in children with AD/AID-HLH. Patients were first treated with RUX monotherapy, and additional treatments including methylprednisolone and etoposide were added sequentially when the disease could not be controlled. The study included 26 patients with a median follow-up of 23.9 months, of whom 15 had prior treatments. The overall response rate at week 8 with the RUX-based regimen was 96.2%, with 92.3% attaining complete response (CR) and 3.9% attaining partial response. The 2-year overall survival rate was 96.2% (95% CI, 80.4% to 99.9%). During RUX monotherapy, 46.1% of patients achieved CR as the best response, with a median first response time to RUX of 2 days. Additionally, 53.8% of patients required additional GCs and 23.1% required etoposide chemotherapy. All observed adverse events were manageable and acceptable. Overall, our study supports the efficacy and safety of the RUX-based regimen in children with AD/AID-HLH.

A hidden enemy: Understanding the hemophagocytic syndrome in children under five years of age in a high-complexity institution in southwestern Colombia

Introduction. Hemophagocytic syndrome is an under-recognized condition with high mortality in the pediatric population. It is characterized by excessive activation of immune cells and cytokine release, leading to persistent inflammation. Hemophagocytic syndrome can be primary or secondary and associated with different triggers. Objective. To describe 12 clinical cases of children under five years of age with hemophagocytic syndrome in a high-complexity institution in southwestern Colombia. Materials and methods. We present a retrospective series of 12 cases of hemophagocytic syndrome in children under five years of age treated at a high-complexity institution in Colombia between 2019 and 2022. Results. The median age of the patients was one year and 7 were male. Fever and splenomegaly were the most common clinical manifestations observed in 11 of the patients. The predominant laboratory findings included hyperferritinemia (n = 11), hypertriglyceridemia (n = 10), bicytopenia (n = 6), and pancytopenia (n = 2). Eleven cases had elevated lactate dehydrogenase levels. Genetic studies were conducted in 7 patients. Regarding treatment, the full HLH-2004 protocol was administered to 5 cases, while 3 underwent hematopoietic stem cell transplantation. Three patients died. Conclusion. We highlight the complexity of the hemophagocytic syndrome, especially in children under five years old, because the low prevalence and non-specific clinical presentation of the disease contribute to its underdiagnosis. Emphasis is placed on identifying triggers, performing genetic evaluation for accurate and early diagnosis, adopting a multidisciplinary approach, and considering early hematopoietic stem cell transplantation to improve morbidity and mortality outcomes.

Increased ferritin, serum lactate dehydrogenase, and aspartate aminotransferase levels predict macrophage activation syndrome complicating systemic lupus erythematosus: a retrospective study

Background

This study aimed to assess the diagnosis of macrophage activation syndrome (MAS) at the onset of active childhood-onset systemic lupus erythematosus (cSLE), which is under-researched, and to compare the characteristics of cSLE with and without MAS, hypothesizing the existence of possible predictors of MAS in active cSLE.

Methods

This study enrolled 157 patients diagnosed with cSLE, with or without MAS, from Nanjing Medical University between January 2018 and May 2023. Data analysis was performed using an independent samples t-test or the Mann-Whitney U-test, the χ 2 test, the Youden index to determine the optimal cutoff values for diagnosis, and binary logistic regression analysis to determine the predicted probability.

Results

Fifteen patients (9%) had MAS in the active phase, with an SLE disease activity index of 16.6 (range, 6-32). Bone marrow aspirations revealed hemophagocytosis in 8/15 cases (53%). Fever was the most common feature of MAS patients. Lactate dehydrogenase (LDH) and ferritin levels were elevated in the patients. Lower leukocyte, neutrophil, and platelet counts, including serum sodium and fibrinogen, and increased alanine aminotransferase, aspartate aminotransferase (AST), lactate dehydrogenase (LDH), ferritin, triglyceride, and D-dimer levels occurred in MAS patients, unlike those without MAS. Optimal cutoff values for ferritin (≥607.35 ng/ml), LDH (≥424 U/L), and AST (≥61 U/L) were predictors of MAS occurrence in cSLE. No MAS patients experienced recurrence during an 18-month mean follow-up.

Conclusions

Despite the narrow scope of the study, elevated levels of ferritin, LDH, and AST may represent indicators of cSLE complicated by MAS. Early diagnosis and treatment may improve outcomes.

Prolonged Fever After the Treatment of Ulcerative Colitis in an Adolescent

A 17-year-old female was diagnosed with inflammatory bowel disease and started on infliximab. A few weeks after starting infliximab, she developed a recurrence of daily fevers associated with an intermittent dry cough, which worsened over the course of a month. A chest radiograph, abdominal ultrasound, and computed tomography scan of the chest and abdomen revealed a heterogeneous spleen with multiple hyperechoic areas, tiny splenic micronodules, and diffuse micronodularity throughout the lungs. She was transferred to a tertiary care hospital because of hypotension, new oxygen requirements, and ongoing fever. Her bloodwork on presentation to tertiary care revealed pancytopenia and elevated inflammatory markers; she had splenomegaly on MRI. As her clinical picture evolved, she continued to have persistent fevers and anorexia despite ongoing management. Infectious diseases, rheumatology, and gastroenterology were consulted to guide the evaluation and management of this patient's complex clinical course.

Evaluating treatment practices and challenges in systemic Juvenile Idiopathic Arthritis: a comprehensive survey analysis

OBJECTIVE

This study aims to assess current diagnostic and management for systemic Juvenile Idiopathic Arthritis (sJIA) among physicians, evaluate the challenges encountered in diagnosis and treatment, and identify the educational needs and professional development engagements of physicians managing sJIA.

METHODS

A nationwide survey was conducted from November 2023 to March 2024 across tertiary and secondary pediatric and general hospitals in China. The survey targeted physicians with at least three years of specialty experience, resulting in 310 valid responses from 25 provinces, autonomous regions, and municipalities. The survey collected data on diagnostic practices, treatment approaches, and professional development related to sJIA. Data collection was facilitated through WeChat, and statistical analysis was performed using descriptive statistics. Ethical approval was obtained from the Ethics Committee of Beijing Children's Hospital, with informed consent provided electronically by participants.

RESULTS

The survey indicated that all physicians encountered suspected or confirmed cases of sJIA, highlighting its prevalence and the diagnostic challenges associated. Regarding diagnostic standards, 53.9% of physicians used the "Consensus on the Diagnosis and Treatment of sJIA and Macrophage Activation Syndrome," 18.1% followed the International League of Associations for Rheumatology (ILAR) standards, and 24.8% adhered to the Pediatric Rheumatology International Trials Organization (PRINTO) standards. In treatment strategies, glucocorticoids and IL-6 receptor monoclonal antibodies were extensively used, with the latter receiving "excellent" and "satisfactory" ratings of 46.5% and 36.1%, respectively, demonstrating high efficacy and acceptance. Main challenges included high treatment costs, complexity of diagnosis, patient compliance issues, and potential long-term side effects of biologics. Additionally, 126 doctors (40.7%) actively participated in more than three academic conferences or systematic learning courses related to sJIA, indicating a strong demand for ongoing education, particularly in new treatment developments and diagnostic skills.

CONCLUSION

The findings emphasize the necessity for standardized diagnosis and customized treatment plans tailored to patient-specific conditions in managing sJIA. Key Points • The survey highlights the prevalence and clinical challenges of sJIA among physicians, emphasizing the importance of vigilant diagnosis, multi-system involvement, and differential diagnosis to improve treatment outcomes and patient quality of life.

Role of DOCK8 in cytokine storm syndromes

BACKGROUND

Cytokine storm syndromes (CSSs), including hemophagocytic lymphohistiocytosis (HLH), are increasingly recognized as hyperinflammatory states leading to multiorgan failure and death. Familial HLH in infancy results from homozygous genetic defects in perforin-mediated cytolysis by CD8 T lymphocytes and natural killer (NK) cells. Later-onset CSSs are often associated with heterozygous defects in familial HLH genes, but genetic etiologies for most are unknown. We identified rare dedicator of cytokinesis 8 (DOCK8) variants in patients with CSS.

OBJECTIVE

We sought to explore the role of CSS patient-derived DOCK8 mutations on cytolytic activity in NK cells and to further study effects of DOCK8 deficiency in murine models of CSSs.

METHODS

DOCK8 cDNAs from 2 unrelated patients with CSS with different missense mutations were introduced into human NK-92 cells by foamy virus transduction. NK-cell degranulation (CD107a), cytolytic activity against K562 target cells, and IFN-γ production were explored by flow cytometry. A third patient with CSS with DOCK8 mRNA splice acceptor site variant was explored by exon trapping. Dock8-/- mice were assessed for features of CSS (weight loss, splenomegaly, hepatic inflammation, cytopenias, and IFN-γ levels) on challenge with lymphocytic choriomeningitis virus and excess IL-18.

RESULTS

Both patient DOCK8 missense mutations decreased cytolytic function in NK cells in a partial dominant-negative fashion in vitro. The patient DOCK8 splice variant disrupted mRNA splicing in vitro. Lymphocytic choriomeningitis virus infection promoted CSS in Dock8-/- mice and interacted with excess IL-18, limiting T-cell numbers while promoting CD8 T-cell hyperactivation.

CONCLUSIONS

Mutations in DOCK8 may contribute to CSS-like hyperinflammatory states by altering cytolytic function in a threshold model of disease.

CircMETTL3-156aa reshapes the glycolytic metabolism of macrophages to promote M1 polarization and induce cytokine storms in sHLH

Persistent macrophage activation and cytokine storms are critical causes for the rapid disease progression and high mortality rate of Secondary Hemophagocytic lymphohistiocytosis (sHLH). Identification of key regulatory factors that govern the activation of macrophages is vital. Plasma exosomal circular RNAs (circRNAs) are considered important biomarkers and potential therapeutic targets for various diseases, however, their function in sHLH is still unclear. In this study, we demonstrated for the first time that circMETTL3, derived from METTL3, is upregulated in sHLH patient plasma exosomes, which may plays an important role in the diagnosis of sHLH. Significantly, we also revealed that a novel peptide encoded by circMETTL3, METTL3-156aa, is an inducer of M1 macrophage polarization, which is responsible for the development of cytokine storms during sHLH. We then identified that METTL3-156aa binding with lactate dehydrogenase A (LDHA) and promotes M1 macrophage polarization by enhancing macrophage glycolysis. Additionally, the glycolysis metabolite lactate upregulates the cleavage factor SRSF10 expression by lactylation. This results in increased splicing of the pre-METTL3 mRNA, leading to an enchance in the production of cirMETTL3. Therefore, our results suggest that the circMETTL3/METTL3-156aa/LDHA/Lactate/SRSF10 axis forms a positive feedback loop and may be a novel therapeutic target for the treatment of sHLH.

How do we manage hyperhemolysis syndrome

BACKGROUND

Hyperhemolysis syndrome (HHS) is a catastrophic anemia characterized by destruction of both donor and patient red blood cells (RBC). HHS occurs after transfusion and can cause significant morbidity and mortality. Given the difficulty in diagnosing and managing this process, we provide a detailed overview of our treatment protocol.

STUDY DESIGN AND METHODS

Members of the Transfusion Medicine and Hematology faculty at our institution collaborated in an iterative process to produce a consensus approach to patients with HHS.

RESULTS

We present diagnostic criteria for HHS: recent transfusion within past 7 days (up to 21 days), rapid hemoglobin decline to below the pretransfusion level (usually hemoglobin drop >25% from pretransfusion), a significant decrease in HbA% (in patients with sickle cell disease or beta thalassemia), low or decreasing reticulocyte count in a patient with worsening anemia, and laboratory evidence of hemolysis. We also describe an in-depth approach to management focusing on optimizing hematopoiesis while dampening the immune response.

CONCLUSION

We provide a comprehensive approach to the diagnosis and management of HHS based on contemporary literature and clinical experience designed to optimize outcomes for patients.

NLRC4, inflammation and colorectal cancer (Review)

Chronic inflammation is recognized as a major risk factor for cancer and is involved in every phase of the disease. Inflammasomes are central to the inflammatory response and play a crucial role in cancer development. The present review summarizes the role of Nod‑like receptor C4 (NLRC4) in inflammation and colorectal cancer (CRC). Reviews of the literature were conducted using Web of Science, PubMed and CNKI, with search terms including 'NLRC4', 'colorectal cancer', 'auto‑inflammatory diseases' and 'prognosis'. Variants of NLRC4 can cause recessive immune dysregulation and autoinflammation or lead to ulcerative colitis as a heterozygous risk factor. Additionally, genetic mutations in inflammasome components may increase susceptibility to cancer. NLRC4 is considered a tumor suppressor in CRC. The role of NLRC4 in CRC signaling pathways is currently understood to involve five key aspects (caspase 1, NLRP3/IL‑8, IL‑1β/IL‑1, NAIP and p53). The mechanisms by which NLRC4 is involved in CRC are considered to be threefold (through pyroptosis, apoptosis, necroptosis and PANoptosis; regulating the immune response; and protecting intestinal epithelial cells to prevent CRC). However, the impact of NLRC4 mutations on CRC remains unclear. In conclusion, NLRC4 is a significant inflammasome that protects against CRC through various signaling pathways and mechanisms. The association between NLRC4 mutations and CRC warrants further investigation.

The effectiveness of the doxorubicin-etoposide-methylprednisolone regimen for adult HLH secondary to rheumatic disease

To investigate the efficacy of the doxorubicin-etoposide-methylprednisolone, DEP) regimen as an effective treatment for adult Hemophagocytic Lymphohistiocytosis secondary to rheumatic disease and analyze prognosis in these patients. Fifty-eight adult patients diagnosed with Hemophagocytic Lymphohistiocytosis secondary to rheumatic disease admitted to Beijing Friendship Hospital from 1st Jan. 2018 to 31st Dec. 2022 were retrospectively included in this study. Patients were grouped according to previous treatment. Clinical data and laboratory characteristics of patients were retrospectively analyzed. The efficacy was evaluated every 2 weeks after initiating the first course of the DEP regimen and until the last inpatient or 31st Dec. 2023. 26 patients were included in Group A and 32 patients were included in Group B due to the previous treatment. After the first course of the DEP regimen, the overall response rate of all patients was 82.8%, with 13.8% in complete response and 69% in partial response. There was no significant statistical objective response rate between the two groups after the DEP regimen, except at 2-week. Serum ferritin, sCD25, ALT, AST, and DBIL concentrations were significantly lower at 2, 4 and 6-week than pre-treatment (P < 0.05). The overall mortality rate is 20.7% (12/58). Importantly, advanced age, initial level of HB and PLT, and central nervous system (CNS) involvement were independent poor risk factors affecting OS in bivariate analysis. The DEP regimen is effective for adult HLH secondary rheumatic disease with a high overall rate and accepted side effects.

Clinical and genetic analysis of macrophage activation syndrome complicating juvenile idiopathic inflammatory myopathies

BACKGROUND

Macrophage activation syndrome (MAS) is a serve complication of juvenile idiopathic inflammatory myopathies (JIIMs). This study delineates the clinical manifestations and genetic underpinnings of JIIM-MAS patients.

METHODS

We retrospectively analysed clinical and UNC13D gene from JIIM patients admitted to our centre between 2011 and 2021 to identify cases of MAS. Additionally, a literature review summarising reported cases of JIIMs and MAS was performed.

RESULTS

Of 773 JIIM patients, 10 (1.3%) were diagnosed with MAS. All patients presented with persistent fever and hyperferritinaemia. Seventy percent of patients met the HLH-2004 criteria, while 90% met the 2016 sJIA-MAS criteria. Most patients received combined treatment of corticosteroids and immunosuppressants. UNC13D gene analysis was performed in six patients. A homozygous pathogenic mutation (c.2588G>A) was detected in one patient with recurrent MAS, and twenty-eight single-nucleotide polymorphisms (SNPs) were detected. Eighty percent of patients exhibiting a consistent combination of ten SNPs compared to JIIM patients without MAS (35%).

CONCLUSION

MAS is an early and often overlooked complication of JIIMs. The 2016 sJIA-MAS criteria may facilitate early diagnosis. Combined corticosteroid and immunosuppressant therapy prove effective. An increased prevalence of UNC13D gene polymorphisms was observed in JIIM-MAS patients, highlighting the necessity for further investigations.

IMPACT

This study aimed to delineate the clinical manifestations and genetic underpinnings of macrophage activation syndrome (MAS) in ten patients with juvenile idiopathic inflammatory myopathies (JIIMs). MAS has been recognised as a complication of JIIMs. However, only a few case reports provide comprehensive descriptions of MAS in JIIM patients, and there are few reports related to UNC13D mutations in these patients. This article offers single-centre clinical insights to enhance the identification and management of MAS in JIIM patients, while also highlighting the potential association between MAS occurrence and UNC13D gene polymorphisms.

Case report: Macrophage activation syndrome in a patient with Kabuki syndrome

Macrophage activation syndrome (MAS), is a severe and fatal complication of various pediatric inflammatory disorders. Kabuki syndrome (KS), mainly caused by lysine methyltransferase 2D (KMT2D; OMIM 602113) variants, is a rare congenital disorder with multi-organ deficiencies. To date, there have been no reported cases of MAS in patients with KS. This report describes a case of a 22-year-old male with Kabuki syndrome (KS) who developed MAS. This unique case not only deepens the understanding of the involvement of KMT2D in immune regulation and disease, but expands the phenotype of the adult patient to better understand the natural history, disease burden, and management of patients with KS complicated with autoimmune disorders.

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.

Initial Respiratory System Involvement in Juvenile Idiopathic Arthritis with Systemic Onset Is a Marker of Interstitial Lung Disease: The Results of Retrospective Cohort Study Analysis

Background: Pulmonary involvement in systemic juvenile idiopathic arthritis (SJIA) is a rare but dangerous complication. The main risk factors are already known, such as macrophage activation syndrome, a refractory course of systemic juvenile arthritis, infusion reaction to interleukin 1 and/or interleukin 6 blockers, trisomy 21, and eosinophilia. However, information about respiratory system involvement (RSI) at the onset of SJIA is scarce. Our study aimed to evaluate the specific features of children with SJIA with RSI and their outcomes. Methods: In a single-center retrospective cohort study, we compared the information from the medical records of 200 children with SJIA according to ILAR criteria or SJIA-like disease (probable/possible SJIA) with and without signs of RSI (dyspnea, shortness of breath, pleurisy, acute respiratory distress syndrome, and interstitial lung disease (ILD)) at the disease onset and evaluated their outcomes (remission, development of chronic ILD, clubbing, and pulmonary arterial hypertension). Results: A quarter (25%) of the SJIA patients had signs of the RSI at onset and they more often had rash; hepato- and splenomegaly; heart (pericarditis, myocarditis), central nervous system, and kidney involvement; hemorrhagic syndrome; macrophage activation syndrome (MAS, 44.4% vs. 9.0%, p = 0.0000001); and, rarely, arthritis with fewer active joints, compared to patients without RSI. Five patients (10% from the group having RSI at the onset of SJIA and 2.5% from the whole SJIA cohort) developed fibrosing ILD. All of them had a severe relapsed/chronic course of MAS; 80% of them had a tocilizumab infusion reaction and further switched to canakinumab. Unfortunately, one patient with Down's syndrome had gone. Conclusion: Patients with any signs of RSI at the onset of the SJIA are required to be closely monitored due to the high risk of the following fibrosing ILD development. They required prompt control of MAS, monitoring eosinophilia, and routine checks of night oxygen saturation for the prevention/early detection of chronic ILD.

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.

Universal CAR 2.0 to overcome current limitations in CAR therapy

Chimeric antigen receptor (CAR) T cell therapy has effectively complemented the treatment of advanced relapsed and refractory hematological cancers. The remarkable achievements of CD19- and BCMA-CAR T therapies have raised high expectations within the fields of hematology and oncology. These groundbreaking successes are propelling a collective aspiration to extend the reach of CAR therapies beyond B-lineage malignancies. Advanced CAR technologies have created a momentum to surmount the limitations of conventional CAR concepts. Most importantly, innovations that enable combinatorial targeting to address target antigen heterogeneity, using versatile adapter CAR concepts in conjunction with recent transformative next-generation CAR design, offer the promise to overcome both the bottleneck associated with CAR manufacturing and patient-individualized treatment regimens. In this comprehensive review, we delineate the fundamental prerequisites, navigate through pivotal challenges, and elucidate strategic approaches, all aimed at paving the way for the future establishment of multitargeted immunotherapies using universal CAR technologies.

Unleashing the Cytokine Storm: A Case of Macrophage Activation Syndrome in Systemic Lupus Erythematosus

Macrophage activation syndrome (MAS), synonymous with secondary hemophagocytic lymphohistiocytosis (HLH), is a rare and critical complication of rheumatologic disease stemming from the unregulated activation and rapid multiplication of macrophages and T lymphocytes. While it primarily manifests in children diagnosed with systemic juvenile idiopathic arthritis (sJIA), it can arise less frequently in other rheumatologic conditions. Here, we outline the clinical course, treatment, and outcome of MAS diagnosed in an 18-year-old female previously diagnosed with SLE who exhibited a unique clinical presentation.

Expanding the role of CAR T-cell therapy: From B-cell hematological malignancies to autoimmune rheumatic diseases

Chimeric antigen receptor (CAR) T-cell therapy is a form of immunotherapy where the lymphocytes, mostly T-cells, are redirected to specifically recognize and eliminate a target antigen by coupling them with CARs. The binding of CAR and target cell surface antigens leads to vigorous T cell activation and robust anti-tumor immune responses. Areas of implication of CAR T-cell therapies include mainly hematological malignancies (i.e., advanced B-cell cancers); however, recent studies have proven the unprecedented success of the new immunotherapy also in autoimmune rheumatic diseases. We aim to review the recent advances in CAR T-cell therapies in rheumatology but also to address the limitations of their use in the real clinical practice based on the data on their efficacy and safety.

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.

Murine Models of Secondary Cytokine Storm Syndromes

Hemophagocytic lymphohistiocytosis (HLH) comprises a broad spectrum of life-threatening cytokine storm syndromes, classified into primary (genetic) or secondary (acquired) HLH. The latter occurs in a variety of medical conditions, including infections, malignancies, autoimmune and autoinflammatory diseases, acquired immunodeficiency, and metabolic disorders. Despite recent advances in the field, the pathogenesis of secondary HLH remains incompletely understood. Considering the heterogeneity of triggering factors and underlying diseases in secondary HLH, a large diversity of animal models has been developed to explore pivotal disease mechanisms. To date, over 20 animal models have been described that each recapitulates certain aspects of secondary HLH. This review provides a comprehensive overview of the existing models, highlighting relevant findings, discussing the involvement of different cell types and cytokines in disease development and progression, and considering points of interest toward future therapeutic strategies.

Laboratory Features and Pathology of Cytokine Storm Syndromes

The laboratory diagnosis of cytokine storm syndromes (CSSs), i.e., hemophagocytic lymphohistiocytosis (HLH) and macrophage activation syndrome (MAS), is often challenging. The laboratory features using routinely available tests lack specificity, whereas confirmatory testing is available in only few laboratories in the United States. The disease mechanisms are still largely unclear, particularly in adults. In this chapter, the pathogenesis of CSSs, their associated laboratory findings, and recommended diagnostic strategies are reviewed.

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.

Etoposide Therapy of Cytokine Storm Syndromes

Etoposide has revolutionized the treatment of primary as well as secondary hemophagocytic lymphohistiocytosis (HLH), and it is, together with corticosteroids, the most widely used therapy for HLH. In the early 1980s, long-term survival in primary HLH was <5% but with the etoposide-/dexamethasone-based protocols HLH-94 and HLH-2004, in combination with stem cell transplantation, 5-year survival increased dramatically to around 60% in primary HLH, and based on analyses from the HLH-2004 study, there is likely room for further improvement. Biologically, etoposide administration results in potent selective deletion of activated T cells as well as efficient suppression of inflammatory cytokine production. Moreover, etoposide has also been reported to promote programmed cell death (apoptosis) rather than proinflammatory lytic cell death (pyroptosis), conceivably ameliorating subsequent systemic inflammation, i.e., a treatment very suitable for cytokine storm syndromes (CSS). The combination of etoposide and corticosteroids may also be beneficial in cases of severe or refractory secondary HLH (sHLH) with imminent organ failure, such as infection-associated HLH caused by Epstein-Barr virus (EBV) or malignancy-triggered HLH. In CSS associated with rheumatic diseases (macrophage activation syndrome, MAS or MAS-HLH), etoposide is currently used as second- or third-line therapy. Recent studies suggest that etoposide perhaps should be part of an aggressive therapeutic intervention for patients with severe refractory or relapsing MAS, in particular if there is CNS involvement. Importantly, awareness of sHLH must be further increased since treatment of sHLH is often delayed, thereby missing the window of opportunity for a timely, effective, and potentially life-saving HLH-directed treatment.

Early response markers predict survival after etoposide-based therapy of hemophagocytic lymphohistiocytosis

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening hyperinflammatory syndrome that is most commonly treated with etoposide and dexamethasone. This standard of care therapy has improved survival, but ∼15% of patients still die in the first months after diagnosis, and poor responses prompting salvage therapy are frequent. Thus, identifying patients at risk promptly is likely to improve outcomes. We conducted a multi-institutional, retrospective study of pediatric and young adults treated per HLH-94 or HLH-2004 from 2010 to 2019 to identify patients at risk for early mortality. Biweekly data during the first 100 days of treatment were analyzed using receiver operating curves to define optimal prognostic indicators and their thresholds. The primary end point was survival to bone marrow transplant (BMT) or ∼1 year if no BMT was pursued. Eighty-nine patients met the study inclusion criteria. Pre-BMT mortality was 13% (n = 12), and overall mortality was 27% (n = 24). Laboratory markers measured on day 7 of therapy more efficiently predicted outcomes than did either pretreatment or later assessments. The most potent day 7 unfavorable marker was improvement in soluble CD25 (sCD25) of less than 25% from pretherapy levels. Absolute sCD25 level, platelet count, absolute lymphocyte count, and blood urea nitrogen were also discriminatory markers (area under the curve ≥ 0.7). The presence of ≥3 of these unfavorable markers was strongly associated with pre-BMT mortality (accuracy, 0.93). Thus, serial monitoring of sCD25 and assessment of other early (day 7) response markers optimally predicts prognosis with etoposide-based therapy and may indicate the need for earlier use of alternative, response-adapted therapeutic strategies for HLH.

Elevated monocyte HLA-DR in pediatric secondary hemophagocytic lymphohistiocytosis: a retrospective study

Introduction

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening condition, and its diagnosis may be challenging. In particular, some cases show close similarities to sepsis (fever, organ failure, and high ferritin), but their treatment, while urgent, differ: prompt broad-spectrum antibiotherapy for sepsis and immunosuppressive treatment for HLH. We questioned whether monocyte human leucocyte antigen (mHLA)-DR could be a diagnostic marker for secondary HLH (sHLH).

Methods

We retrospectively reviewed data from patients with a sHLH diagnosis and mHLA-DR quantification. mHLA-DR data from healthy children and children with septic shock, whose HLA-DR expression is reduced, from a previously published study were also included for comparison.

Results

Six patients with sHLH had mHLA-DR quantification. The median level of monocyte mHLA-DR expression in patients with sHLH [79,409 antibodies bound per cell (AB/C), interquartile range (IQR) (75,734-86,453)] was significantly higher than that in healthy children and those with septic shock (29,668 AB/C, IQR (24,335-39,199), and 7,493 AB/C, IQR (3,758-14,659), respectively). Each patient with sHLH had a mHLA-DR higher than our laboratory normal values. Four patients had a second mHLA-DR sampling 2 to 4 days after the initial analysis and treatment initiation with high-dose corticosteroids; for all patients, mHLA-DR decreased to within or close to the normal range. One patient with systemic juvenile idiopathic arthritis had repeated mHLA-DR measurements over a 200-day period during which she underwent four HLH episodes. mHLA-DR increased during relapses and normalized after treatment incrementation.

Conclusion

In this small series, mHLA-DR was systematically elevated in patients with sHLH. Elevated mHLA-DR could contribute to sHLH diagnosis and help earlier distinction with septic shock.

Glomerular lipidosis as a feature of renal-limited macrophage activation syndrome in a transplanted kidney: a case report

BACKGROUND

Glomerular lipidosis is a rare histological feature presenting the extensive glomerular accumulation of lipids with or without histiocytic infiltration, which develops under various conditions. Among its various etiologies, macrophage activation syndrome (MAS) is a condition reported to be associated with histiocytic glomerular lipidosis. Here we describe the first case of glomerular lipidosis observed in a renal allograft that histologically mimicked histiocytic glomerulopathy owing to MAS.

CASE PRESENTATION

A 42-year-old man underwent successful living-donor kidney transplantation. However, middle-grade proteinuria and increased serum triglyceride levels indicative of type V hyperlipidemia developed rapidly thereafter. An allograft biopsy performed 6 months after the transplantation showed extensive glomerular infiltration of CD68+ foam cells (histiocytes) intermingled with many CD3+ T-cells (predominantly CD8+ cells). Furthermore, frequent contact between glomerular T-cells and histiocytes, and the existence of activated CD8+ cells (CD8+, HLA-DR+ cells) were observed by double immunostaining. There was no clinicopathological data suggesting lipoprotein glomerulopathy or lecithin cholesterol acyltransferase deficiency, both of which are well-known causes of glomerular lipidosis. The histological findings were relatively similar to those of histiocytic glomerulopathy caused by MAS. As systemic manifestations of MAS, such as fever, pancytopenia, coagulation abnormalities, hyperferritinemia, increased liver enzyme levels, hepatosplenomegaly, and lymphadenopathy were minimal, this patient was clinicopathologically diagnosed as having renal-limited MAS. Although optimal treatment strategies for MAS in kidney transplant patients remains unclear, we strengthened lipid-lowering therapy using pemafibrate, without modifying the amount of immunosuppressants. Serum triglyceride levels were normalized with this treatment; however, the patient's extensive proteinuria and renal dysfunction did not improve. Biopsy analysis at 1 year after the transplantation demonstrated the disappearance of glomerular foamy changes, but the number of glomerular infiltrating cells remained similar.

CONCLUSION

To our knowledge, this is the first reported case of glomerular lipidosis in a transplanted kidney. Increased interaction-activation of histiocytes (macrophages) and CD8+ T-cells, the key pathogenic feature of MAS, was observed in the glomeruli of this patient, who did not demonstrate overt systemic manifestations, suggesting a pathological condition of renal-limited MAS. The clinical effects of triglyceride-lowering therapy were limited, suggesting that hypertriglyceridemia was not the cause of but rather may be a consequence of renal-limited MAS.

Implementing a Disease-specific Multidisciplinary Team and Order Set for Hemophagocytic Lymphohistiocytosis in a Pediatric Hospital

OBJECTIVE

To improve outcomes of hemophagocytic lymphohistiocytosis (HLH), prompt recognition and treatment are necessary. A HLH multidisciplinary team was implemented at our institution, and we established an electronic order set to foster uniformity in the diagnostic approach. The goal of this study is to capture the impact of this diagnostic tool.

METHODS

This is a retrospective study analyzing the utilization of a HLH-specific order set since time of implementation in June 2019 through December 2022. The trends in the utilization of the order set by providers were analyzed to evaluate the awareness and effectiveness of this tool.

RESULTS

The order set was utilized 50 times, most commonly by hematology/oncology (50%) and infectious disease (26%). Utilization by providers on newly presenting patients included 4 times in the year 2019, 12 times in 2020, 16 times in 2021, and 18 times in 2022. Utilization was associated with the diagnosis of HLH in 9 patients (18%).

CONCLUSION

Implementation of an HLH-specific order set facilitated a systematic method to approach patients with suspected HLH. The utilization of the order set displayed an upward trend over time, indicating support of this tool among these providers. This tool can increase awareness and early identification of HLH.

Macrophage activation syndrome induced by Staphylococcus Epidermidis in a pediatric patient with cystic fibrosis and familial Mediterranean fever

Staphylococcus epidermidis (S. epidermidis) is the most frequently isolated member of the coagulase-negative staphylococci, which colonizes the skin and mucous membranes of the human body. Despite being a component of the normal flora, S. epidermidis can act as an opportunistic pathogen and is frequently implicated in both bacterial and nosocomial infections. Macrophage activation syndrome (MAS) is a rare but potentially fatal disease that occurs as a result of increased activation and proliferation of T lymphocytes and macrophages in response to infections and immune mediated diseases. It is very rare in patients with cystic fibrosis. Here we report a case of an 8-year-old girl with cystic fibrosis and familial Mediterranean fever who developed MAS after contracting a S. epidermidis infection.

Case Report: A Case of Bone Marrow Necrosis and Hyperinflammation in a 10-Year-Old Boy after Plasmodium falciparum Infection

A 10-year-old boy with sickle cell disease (SCD) type SC presented with fever and abdominal pain after travel to Ghana and was diagnosed with Plasmodium falciparum infection. Despite adequate antimalarial treatment, he developed evidence of hyperinflammation with marked elevated ferritin, C-reactive protein, and triglycerides and subsequent bone marrow necrosis, characterized by elevated nucleated red blood cells and significant bone pain. This case report highlights the possible association between malaria and bone marrow necrosis in patients with SCD. Important considerations in treatment and workup of patients presenting with malaria and hyperinflammation are discussed.

The JAK1/2 inhibitor ruxolitinib in patients with COVID-19 triggered hyperinflammation: the RuxCoFlam trial

Dysregulated hyperinflammatory response is key in the pathogenesis in patients with severe COVID-19 leading to acute respiratory distress syndrome and multiorgan failure. Whilst immunosuppression has been proven to be effective, potential biological targets and optimal timing of treatment are still conflicting. We sought to evaluate efficacy and safety of the Janus Kinase 1/2 inhibitor ruxolitinib, employing the previously developed COVID-19 Inflammation Score (CIS) in a prospective multicenter open label phase II trial (NCT04338958). Primary objective was reversal of hyperinflammation (CIS reduction of ≥25% at day 7 in ≥20% of patients). In 184 patients with a CIS of ≥10 (median 12) ruxolitinib was commenced at an initial dose of 10 mg twice daily and applied over a median of 14 days (range, 2-31). On day 7, median CIS declined to 6 (range, 1-13); 71% of patients (CI 64-77%) achieved a ≥25% CIS reduction accompanied by a reduction of markers of inflammation. Median cumulative dose was 272.5 mg/d. Treatment was well tolerated without any grade 3-5 adverse events related to ruxolitinib. Forty-four patients (23.9%) died, all without reported association to study drug. In conclusion, ruxolitinib proved to be safe and effective in a cohort of COVID-19 patients with defined hyperinflammation.

Secondary hemophagocytic lymphohistiocytosis in children (Review)

Hemophagocytic lymphohistiocytosis (HLH) is a rare, life-threatening condition characterized by hyperinflammation in an uncontrolled and ineffective immune response. Despite great improvement in diagnosis and treatment, it still represents a challenge in clinical management, with poor prognosis in the absence of an aggressive therapeutic approach. The present literature review focuses on secondary HLH at pediatric age, which represents a heterogeneous group in terms of etiology and therapeutic approach. It summarizes the most recent evidence on epidemiology, pathophysiology, diagnosis, treatment and prognosis, and provides a detailed description and comparison of the major subtypes of secondary HLH. Finally, it addresses the open questions with a focus on diagnosis and new treatment insights.

Cytokine Storm Syndromes in Pediatric Patients

Cytokine storm syndromes (CSS) represent a diverse group of disorders characterized by severe overactivation of the immune system. In the majority of patients, CSS arise from a combination of host factors, including genetic risk and predisposing conditions, and acute triggers such as infections. CSS present differently in adults than in children, who are more likely to present with monogenic forms of these disorders. Individual CSS are rare, but in aggregate represent an important cause of severe illness in both children and adults. We present 3 rare, illustrative cases of CSS in pediatric patients that describe the spectrum of CSS.

Triple immune modulator therapy for aberrant hyperinflammatory responses in severe COVID-19

A dysregulated hyperinflammatory response is a key pathogenesis of severe COVID-19, but optimal immune modulator treatment has not been established. To evaluate the clinical effectiveness of double (glucocorticoids and tocilizumab) and triple (plus baricitinib) immune modulator therapy for severe COVID-19, a retrospective cohort study was conducted. For the immunologic investigation, a single-cell RNA sequencing analysis was performed in serially collected PBMCs and neutrophil specimens. Triple immune modulator therapy was a significant factor in a multivariable analysis for 30-day recovery. In the scRNA-seq analysis, type I and II IFN response-related pathways were suppressed by GC, and the IL-6-associated signature was additionally downregulated by TOC. Adding BAR to GC and TOC distinctly downregulated the ISGF3 cluster. Adding BAR also regulated the pathologically activated monocyte and neutrophil subpopulation induced by aberrant IFN signals. Triple immune modulator therapy in severe COVID-19 improved 30-day recovery through additional regulation of the aberrant hyperinflammatory immune response.

The Multifaceted Immunology of Cytokine Storm Syndrome

Cytokine storm syndromes (CSSs) are potentially fatal hyperinflammatory states that share the underpinnings of persistent immune cell activation and uninhibited cytokine production. CSSs can be genetically determined by inborn errors of immunity (i.e., familial hemophagocytic lymphohistiocytosis) or develop as a complication of infections, chronic inflammatory diseases (e.g., Still disease), or malignancies (e.g., T cell lymphoma). Therapeutic interventions that activate the immune system such as chimeric Ag receptor T cell therapy and immune checkpoint inhibition can also trigger CSSs in the setting of cancer treatment. In this review, the biology of different types of CSSs is explored, and the current knowledge on the involvement of immune pathways and the contribution of host genetics is discussed. The use of animal models to study CSSs is reviewed, and their relevance for human diseases is discussed. Lastly, treatment approaches for CSSs are discussed with a focus on interventions that target immune cells and cytokines.

Clinical and Laboratory Characteristics of Hemophagocytic Lymphohistiocytosis in Children With Severe Dengue During the 2019-2020 Outbreak in Southern Colombia

BACKGROUND

Hemophagocytic lymphohistiocytosis (HLH) is characterized by uncontrolled activation of inflammatory cells and an exaggerated release of cytokines. It can be triggered by different factors, including viruses, such as dengue. The objective of this study was to characterize the clinical and laboratory profiles of children with severe dengue and HLH, and to identify the risk factors for this clinical complication.

METHODS

An analytical study was conducted in children with severe dengue who were treated in an intensive care unit between January 2019 and March 2020. Clinical and laboratory factors were compared between patients with and without HLH.

RESULTS

HLH represented 13.4% (15/112) of children with severe dengue. Patients with HLH had a long-lasting fever (10.1 vs. 5.8 days; P = 0.012), low hemoglobin levels (7.6 vs. 10.8 g/dL; P = 0.000) and high aspartate aminotransferase values (4443 vs. 1061 U/L; P = 0.002), alanine transaminase (1433 vs. 487 U/L; P = 0.004), partial thromboplastin time (80.6 vs. 51.8 seconds; P = 0.010), prothrombin time (23.5 vs. 19.6 seconds; P = 0.024), triglycerides (333.7 vs. 223.2 mg/dL; P = 0.005), lactate dehydrogenase (4209 vs. 1947 U/L; P = 0.006), soluble CD25 (3488 vs. 1026 pg/mL; P = 0.014), and presented with higher frequency of myocarditis (66.7% vs. 38.3%; P = 0.048), hepatitis (5.3% vs. 1.3%; P = 0.014), bacterial coinfection (73.3% vs. 26.7%; P = 0.010) and fatal outcome (26% vs. 5%; P = 0.037).

CONCLUSIONS

HLH is a serious life-threatening clinical complication of dengue virus infection that must be considered, particularly during outbreaks.

Macrophage Activation Syndrome (MAS): A Case Report and Narrative Review

Hemophagocytic lymphohistiocytosis (HLH) is a rare and life-threatening syndrome of excessive inflammation and tissue destruction secondary to abnormal immune activation. The term macrophage activation syndrome (MAS) is used when HLH develops in the setting of systemic juvenile idiopathic arthritis (SJIA; formerly known as Still's disease), adult-onset Still's disease, or any other rheumatologic disorder. We present a case of a 21-year-old female with a known history of SJIA who presented to the hospital with fever, chills, myalgia, nausea, vomiting, and hypotension. Initial evaluation at the time of presentation suggested sepsis likely due to acute pyelonephritis, and the patient was started on antibiotics and intravenous fluid hydration. However, further workup suggested that her symptoms were non-infectious and were likely due to MAS, a rare complication of SJIA. We promptly diagnosed her, and she received a course of steroids and made an uneventful recovery.

DOCK2 Mutation and Recurrent Hemophagocytic Lymphohistiocytosis

Hemophagocytic lymphohistiocytosis (HLH) is a syndrome resulting from uncontrolled hyper-inflammation, excessive immune system activation, and elevated levels of inflammatory cytokines. HLH can be caused by the inability to downregulate activated macrophages by natural killer (NK) and CD8 cytotoxic T cells through a process reliant on perforin and granzyme B to initiate apoptosis. Homozygous genetic mutations in this process result in primary HLH (pHLH), a disorder that can lead to multi-system organ failure and death in infancy. Heterozygous, dominant-negative, or monoallelic hypomorphic mutations in these same genes can cause a similar syndrome in the presence of an immune trigger, leading to secondary HLH (sHLH). A genetic mutation in a potential novel HLH-associated gene, dedicator of cytokinesis 2 (DOCK2), was identified in a patient with recurrent episodes of sHLH and hyperinflammation in the setting of frequent central line infections. He required baseline immune suppression for the prevention of sHLH, with increased anti-cytokine therapies and corticosteroids in response to flares and infections. Using a foamy-virus approach, the patient's DOCK2 mutation and wild-type (WT) control DOCK2 cDNA were separately transduced into a human NK-92 cell line. The NK-cell populations were stimulated with NK-sensitive K562 erythroleukemia target cells in vitro and degranulation and cytolysis were measured using CD107a expression and live/dead fixable cell dead reagent, respectively. Compared to WT, the patient's DOCK2 mutation was found to cause significantly decreased NK cell function, degranulation, and cytotoxicity. This study speaks to the importance of DOCK2 and similar genes in the pathogenesis of sHLH, with implications for its diagnosis and treatment.

Cytokine Storm Syndrome

Cytokine storm syndrome (CSS), which is frequently fatal, has garnered increased attention with the ongoing coronavirus pandemic. A variety of hyperinflammatory conditions associated with multiorgan system failure can be lumped under the CSS umbrella, including familial hemophagocytic lymphohistiocytosis (HLH) and secondary HLH associated with infections, hematologic malignancies, and autoimmune and autoinflammatory disorders, in which case CSS is termed macrophage activation syndrome (MAS). Various classification and diagnostic CSS criteria exist and include clinical, laboratory, pathologic, and genetic features. Familial HLH results from cytolytic homozygous genetic defects in the perforin pathway employed by cytotoxic CD8 T lymphocytes and natural killer (NK) cells. Similarly, NK cell dysfunction is often present in secondary HLH and MAS, and heterozygous mutations in familial HLH genes are frequently present. Targeting overly active lymphocytes and macrophages with etoposide and glucocorticoids is the standard for treating HLH; however, more targeted and safer anticytokine (e.g., anti-interleukin-1, -6) approaches are gaining traction as effective alternatives.

Macrophage activation syndrome in children with Kikuchi-Fujimoto disease

BACKGROUND

Kikuchi-Fujimoto disease (KFD) is typically a benign, self-limiting inflammatory disease. However, some patients may have a prolonged or recurrent disease course, or present with life-threatening complications such as macrophage activation syndrome (MAS). In this study, we aimed to describe the incidence and clinical features of MAS in KFD and to access potential laboratory markers for the diagnosis of KFD-associated MAS.

METHODS

Patients with KFD were retrospectively enrolled from January 2015 to November 2021 at Shenzhen Children's Hospital. Clinical data were collected from inpatient or outpatient medical records. Data collected included clinical manifestations, laboratory and imaging findings, treatment, and clinical outcomes. Data were analyzed using GraphPad Prism 8.0 statistical software (GraphPad Software Inc., La Jolla, CA, USA). A receiver operating characteristic (ROC) curve analysis was further performed to access the potential predictors for the KFD-MAS diagnosis.

RESULTS

Of 58 patients with a histological diagnosis of KFD, 15 (25.9%) patients had MAS. Compared to patients without MAS, patients with KFD-MAS presented with a higher proportion of skin rash (26.7%, p = 0.01), glucocorticoid treatment (80%, p = 0.003), and disease recurrence (33.3%, p = 0.04). KFD-MAS patients had lower absolute peripheral white blood cell (WBC, p = 0.02), platelet (p = 0.002), serum albumin levels (p = 0.01), and lymphocyte count (p < 0.0001), and higher lactate dehydrogenase (LDH) levels (p < 0.0001). ROC curve analysis showed that the cutoff values of absolute lymphocyte count, an absolute platelet count, serum albumin level, and serum LDH level for KFD-MAS diagnosis were < 1235/μL, < 171 × 10⁶/μL, < 35.6 g/L, and > 679 IU/mL, respectively.

CONCLUSIONS

The presence of KFD-MAS in children may be more common than previously expected, especially in those with skin rash. KFD-MAS may be associated with a higher recurrence rate. An extremely elevated serum LDH level and moderate to severe lymphopenia may be useful diagnostic markers for MAS in KFD.

TRIAL REGISTRATION

Not applicable; this was a retrospective study.

Systemic lupus erythematosus with multicentric reticulohistiocytosis: A case report

BACKGROUND

Multicentric reticulohistiocytosis (MRH)/systemic lupus erythematosus (SLE) overlap syndrome is an uncommon disease in the clinic and is diagnosed through characteristic clinical manifestations, histopathology, and immunopathology. Here, we report the case of a 30-year-old woman with SLE who developed MRH.

CASE SUMMARY

A 30-year-old woman with a history of polyarthritis for the past 12 years had multiple skin nodules on her body for 10 years, including the sacrococcygeal area, dorsum of the hands, interphalangeal joint of the feet and sternoclavicular joint. The histopathology of a biopsy of the distal interphalangeal joint of the hands revealed granulomatous inflammation, fibrous hyperplasia with ground-glass degeneration, inflammatory cell exudation and focal necrosis. The immunohistochemical stains showed positive staining for CD68 and negative staining for S100 and acid-fast staining. The patient was diagnosed with SLE with MRH. Her symptoms were improved after a combined treatment of prednisone, hydroxychloroquine and cyclophosphamide.

CONCLUSION

MRH/SLE overlap syndrome is difficult to diagnose and treat. Cyclophosphamide may be an alternative choice for the treatment of MRH.

A predictive model for identifying secondary underlying diseases of hemophagocytic lymphohistiocytosis

Background

Secondary hemophagocytic lymphohistiocytosis (HLH) is a rare, life-threatening disease of immune hyperactivation that arises in the context of infectious, inflammatory, or neoplastic triggers. The aim of this study was to establish a predictive model for the timely differential diagnosis of the original disease resulting in HLH by validating clinical and laboratory findings to further improve the efficacy of therapeutics for HLH.

Methods

We retrospectively enrolled 175 secondary HLH patients in this study, including 92 patients with hematologic disease and 83 patients with rheumatic disease. The medical records of all identified patients were retrospectively reviewed and used to generate the predictive model. We also developed an early risk score using multivariate analysis weighted points proportional to the β regression coefficient values and calculated its sensitivity and specificity for the diagnosis of the original disease resulting in HLH.

Results

The multivariate logistic analysis revealed that lower levels of hemoglobin and platelets (PLT), lower levels of ferritin, splenomegaly and Epstein-Barr virus (EBV) positivity were associated with hematologic disease, but young age and female sex were associated with rheumatic disease. The risk factors for HLH secondary to rheumatic diseases were female sex [OR 4.434 (95% CI, 1.889-10.407), P =0.001], younger age [OR 6.773 (95% CI, 2.706-16.952), P<0.001], higher PLT level [OR 6.674 (95% CI, 2.838-15.694), P<0.001], higher ferritin level [OR 5.269 (95% CI, 1.995-13.920), P =0.001], and EBV negativity [OR 27.656 (95% CI, 4.499-169.996), P<0.001]. The risk score included assessments of female sex, age, PLT count, ferritin level and EBV negativity, which can be used to predict HLH secondary to rheumatic diseases with an AUC of 0.844 (95% CI, 0.836~0.932).

Conclusion

The established predictive model was designed to help clinicians diagnose the original disease resulting in secondary HLH during routine practice, which might be improve prognosis by enabling the timely treatment of the underlying disease.

Case report: Virus-induced hemophagocytic lymphohistiocytosis in a patient with APECED

Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED), also known as autoimmune polyglandular syndrome type 1 (APS-1) is a rare autosomal recessive inborn error of immunity (IEI), which is accompanied by immune dysregulation. Hypoparathyroidism, adrenocortical failure and candidiasis are its typical manifestations. Here we report about recurrent COVID-19 in a 3-year-old boy with APECED, who developed retinopathy with macular atrophy and autoimmune hepatitis after the first episode of SARS-CoV-2 infection. Primary Epstein-Barr virus infection and a new episode of SARS-CoV-2 infection with COVID pneumonia triggered the development of severe hyperinflammation with signs of hemophagocytic lymphohistiocytosis (HLH): progressive cytopenia (thrombocytopenia, anemia, lymphopenia), hypoproteinemia, hypoalbuminemia, high levels of liver enzymes, hyperferritinemia, increased triglycerides levels; and coagulopathy with a low level of fibrinogen. Treatment with corticosteroids and intravenous immunoglobulins did not lead to a significant improvement. The progression of HLH and COVID-pneumonia resulted in a fatal outcome. The rarity and varied presentation of the HLH symptoms led to diagnostic difficulties and diagnosis delay. HLH should be suspected in a patient with immune dysregulation and impaired viral response. Treatment of infection-HLH is a major challenge due to the difficulties in balancing immunosuppression and management of underlying/triggering infection.

Hemophagocytic Lymphohistiocytosis Associated with Synergistic Defects of AP3B1 and ATM Genes: A Case Report and Literature Review

Hemophagocytic lymphohistiocytosis (HLH) is an overwhelming immune system activation that manifests as hyperinflammation and life-threatening multiple organ failure. However, the clinical manifestations of the systemic inflammatory response in sepsis and fulminant cytokine storm caused by HLH macrophage activation are very similar and difficult to distinguish. HLH triggered by two novel gene defects manifesting with multiorgan dysfunction syndrome (MODS) and distributive shock has not been reported. A 14-year-old male patient was hospitalized with a high fever, his condition deteriorated rapidly, accompanied by cytopenia, shock, and MODS, and he was subsequently transferred to our intensive care unit (ICU) for symptomatic and organ-supportive treatments. Laboratory indicators of cytopenia, hypofibrinogenemia, hypertriglyceridemia, hyperferritinemia, high soluble CD25, low natural killer (NK) cell cytotoxicity, and hemophagocytosis in the bone marrow confirmed the diagnosis of HLH. Molecular genetic analysis revealed that two novel heterozygous gene mutations in AP3B1 (c.3197 C > T) and ATM (c.8077 G > T) might have accounted for the onset. After treatment, the patient’s condition successfully improved. This case report demonstrates the timely determination of underlying triggers and critical care supports (supportive and etiological treatment) of HLH related to the improved outcome.

Egyptian evidence-based consensus on clinical practice guidelines for the diagnosis and treat-to-target management of macrophage activation syndrome in children

Background

Macrophage activation syndrome (MAS) is a severe life-threatening hyperinflammatory state with uncontrolled activation and proliferation of macrophages and T-lymphocytes. MAS has variable causes and risk factors. Early diagnosis and optimum management could be lifesaving.

Our aim was to develop a consensus, evidence-based recommendations for the diagnosis, evaluation, and treat-to-target management of pediatric MAS.

This study was carried out to achieve an Egyptian expert consensus on a treat-to-target management strategy for MAS using the Delphi technique. The multistep process strategy was used in developing a consensus, evidence-based treatment guidelines for MAS, started by developing 7 key clinical questions by a scientific committee according to the Patient/Population, Intervention, Comparison, and Outcomes (PICO) approach. The core leadership team identified pediatric rheumatology clinicians and researchers throughout Egypt. To generate evidence for MAS management, an evidence-based, systematic literature review was done. To obtain a consensus, the Delphi procedure (3 rounds) was used.

Results

Twenty-three expert panel participated in the 3 rounds with a response rate of 100%. A total of 19 recommendations, categorized into 2 sections (11 in the diagnosis section and 8 in management), were obtained. The agreement with the recommendations (ranks 7–9) ranged from 86.9 to 95.7%. The consensus was reached (i.e., ≥75% of respondents strongly agreed or agreed) on all the clinical standards. Algorithms for management have been also developed.

Conclusion

This was an expert, consensus recommendation for the diagnosis and treat to target of MAS, based on the best available evidence and expert opinion. The guidelines fill a gap in the literature as it presents a T2T approach for MAS.