Hyperferritinemia screening to aid identification and differentiation of patients with hyperinflammatory disorders.

High ferritin is an important and sensitive biomarker for hemophagocytic lymphohistiocytosis (HLH), a diverse and deadly group of cytokine storm syndromes. Early action to prevent immunopathology in HLH often includes empiric immunomodulation, which can complicate etiologic work-up and prevent collection of early/pre-treatment research samples. To address this, we instituted an alert system where serum ferritin > 1000ng/mL triggered real-time chart review, assessment of whether the value reflected "inflammatory hyperferritnemia (IHF)", and biobanking of remnant samples from consenting IHF patients. We extracted relevant clinical data; periodically measured serum total IL-18, IL-18 binding protein (IL-18BP), and CXCL9; retrospectively classified patients by etiology into infectious, rheumatic, or immune dysregulation; and subjected a subgroup of samples to a 96-analyte biomarker screen. 180 patients were identified, 30.5% of which had IHF. Maximum ferritin levels were significantly higher in patients with IHF than with either hemoglobinopathy or transplant, and highly elevated total IL-18 levels were distinctive to patients with Stills Disease and/or Macrophage Activation Syndrome (MAS). Multi-analyte analysis showed elevation in proteins associated with cytotoxic lymphocytes in all IHF samples when compared to healthy controls and depression of proteins such as ANGPT1 and VEGFR2 in samples from hyperferritinemic sepsis patients relative to non-sepsis controls. This single-center, real-time IFH screen proved feasible and efficient, validated prior observations about the specificity of IL-18, enabled early sample collection from a complex population, suggested a unique vascular biomarker signature in hyperferritinemic sepsis, and expanded our understanding of IHF heterogeneity.

Comprehensive mapping of immune perturbations associated with secondary hemophagocytic lymphohistiocytosis.

Secondary hemophagocytic lymphohistiocytosis (sHLH) is a hyperinflammatory syndrome characterized by immune disorders. It is imperative to elucidate the immunophenotypic panorama and the interactions among these cells in patients. Human peripheral blood mononuclear cells were collected from healthy donors and sHLH patients and tested using multicolor flow cytometry. We used FlowSOM to explore and visualize the immunophenotypic characteristics of sHLH. By demonstrating the phenotypes of immune cells, we discovered that sHLH patients had significantly higher levels of CD56+ monocytes, higher levels of myeloid-derived suppressor cells, low-density neutrophil-to-T cell ratio, and higher heterogeneous T cell activation than healthy donors. However, natural killer cell cytotoxicity and function were impaired. We then assessed the correlations among 30 immune cell types and evaluated metabolic analysis. Our findings demonstrated polymorphonuclear myeloid-derived suppressor cells, CD56+ monocytes, and neutrophil-to-T cell ratio were elevated abnormally in sHLH patients, which may indicate an association with immune overactivation and inflammatory response. We are expected to confirm that they are involved in the occurrence of the disease through further in-depth research.

Hemophagocytic Lymphohistiocytosis: A Case Series From a Tertiary State Hospital in Malaysia and a Review of Current Literature.

INTRODUCTION: Hemophagocytic lymphohistiocytosis (HLH) is a lethal emergency. Delays in diagnosis and treatment are detrimental to the health of patients. Classical clinical manifestations of HLH include fever, cytopenia, liver dysfunction, central nervous system involvement, and coagulopathy. METHODS: We report seven cases of secondary HLH in adults diagnosed from a total of 1200 bone marrow aspiration and trephine biopsy (BMAT) examinations in our center, with various presentations and underlying triggers including infection, malignancy, and autoimmune disease. RESULTS: HLH can present with non-specific signs and symptoms. CONCLUSION: Early recognition of HLH is crucial to enable the commencement of therapy as early as possible to prevent mortality resulting from multi-organ failure.

HLH-30/TFEB mediates sexual dimorphism in immunity in caenorhabditis elegans.

Sexual dimorphism affects various biological functions, including immune responses. However, the mechanisms by which sex alters immunity remain largely unknown. Using Caenorhabditis elegans as a model species, we showed that males exhibit enhanced immunity against various pathogenic bacteria through the upregulation of HLH-30 (Helix Loop Helix 30/TFEB (transcription factor EB), a transcription factor crucial for macroautophagy/autophagy. Compared with hermaphroditic C. elegans, males displayed increased activity of HLH-30/TFEB, which contributed to enhanced antibacterial immunity. atg-2 (AuTophaGy (yeast Atg homolog) 2) upregulated by HLH-30/TFEB mediated increased immunity in male C. elegans. Thus, the males appear to be equipped with enhanced HLH-30/TFEB-mediated autophagy, which increases pathogen resistance, and this may functionally prolong mate-searching ability with reduced risk of infection.

CRP and sCD25 help distinguish between adult-onset Still's disease and HLH.

OBJECTIVE: Adult-onset Still's disease (AOSD) and secondary hemophagocytic lymphohistiocytosis (sHLH) are both hyperferritinemic cytokine storm syndromes that can be difficult to distinguish from each other in hospitalized patients. The objective of this study was to compare the inflammatory markers ferritin, D-dimer, C-reactive protein (CRP), and soluble CD25 (sCD25) in patients with AOSD and sHLH. These four markers were chosen as they are widely available and represent different aspects of inflammatory diseases: macrophage activation (ferritin); endothelialopathy (D-dimer); interleukin-1/interleukin-6/tumour necrosis factor elevation (CRP) and T cell activation (sCD25). METHODS: This was a single-center retrospective study. Patients diagnosed by the Hematology service at Vancouver General Hospital for AOSD or sHLH from 2009 to 2023 were included. RESULTS: There were 16 AOSD and 44 sHLH patients identified. Ferritin was lower in AOSD than HLH (median 11 360 µg/L vs. 29 020 µg/L, p = .01) while D-dimer was not significantly different (median 5310 mg/L FEU vs. 7000 mg/L FEU, p = .3). CRP was higher (median 168 mg/L vs. 71 mg/L, p <.01) and sCD25 was lower (median 2220 vs. 7280 U/mL, p = .004) in AOSD compared to HLH. The combined ROC curve using CRP >130 mg/L and sCD25< 3900 U/mL to distinguish AOSD from HLH had an area under the curve (AUC) of 0.94 (95% confidence interval 0.93-0.97) with sensitivity 91% and specificity 93%. CONCLUSIONS: These findings suggest that simple, widely available laboratory tests such as CRP and sCD25 can help clinicians distinguish AOSD from HLH in acutely ill adults with extreme hyperferritinemia. Larger studies examining a wider range of clinically available inflammatory biomarkers in a more diverse set of cytokine storm syndromes are warranted.

From multisystem inflammatory syndrome in children to secondary hemophagocytic lymphohistiocytosis a series of misfortunate events: case report and review of literature.

Multisystem inflammatory syndrome of childhood (MIS-C) is a recently described entity in pediatrics post-COVID-19 pandemic. Hemophagocytic lymphohistiocytosis (HLH) is a clinical syndrome caused by an unregulated proliferation of macrophages as well as T lymphocytes. Both entities can be considered overlapping, although distinct criteria for each can be found in the literature. Herein, we report a patient with MIS-C post-COVID-19 infection, complicated with HLH secondary to Plasmodium falciparum malaria from a blood transfusion.

Unmasking the Culprits: A Case of Epstein-Barr Virus-Associated Hemophagocytic Lymphohistiocytosis Presenting With Mouth Ulcers and Nosebleeds.

Hemophagocytic lymphohistiocytosis (HLH) is an aggressive syndrome of excessive immune activation. It usually occurs in children, mainly during the first year of life. Primary hemophagocytic lymphohistiocytosis is more common and usually occurs in immunocompromised patients. Secondary hemophagocytic lymphohistiocytosis, on the other hand, is less common, especially in immunocompetent patients. Here, we intend to present a case of a 55-year-old male patient who had no known immune deficiency, presented with epistaxis, and was found to have Epstein-Barr virus (EBV)-induced hemophagocytic lymphohistiocytosis.

Salvage treatment of ruxolitinib for refractory adenovirus-associated hemophagocytic syndrome post-haploidentical allogeneic stem cell transplantation: a case report.

Background: Hemophagocytic lymphohistiocytosis (HLH) is a rare complication following hematopoietic stem cell transplantation (HSCT). Currently, there is a lack of consensus recommendations for the treatment of post-transplant HLH. This case report emphasizes the successful utilization of ruxolitinib as a salvage therapy for HLH post-HSCT. The aim is to provide valuable insights into the optimal management of this rare and complex complication. Case Description: We present a case study of an 11-year-old male patient diagnosed with severe aplastic anemia who received a haploidentical HSCT. On the 86th day post-transplantation, the patient developed recurrent fever, hepatomegaly, hypertriglyceridemia, severe pancytopenia, and elevated levels of inflammatory factors and ferritin. Hemophagocytosis was observed in the bone marrow, and subsequent DNA next-generation sequencing identified adenovirus type C infection, leading to a diagnosis of adenovirus-associated HLH. After unsuccessful treatment attempts with cidofovir, dexamethasone, immunoglobulin, plasmapheresis, and etoposide, ruxolitinib was administered. Remarkably, the patient's clinical symptoms rapidly improved, and his test results gradually normalized with ruxolitinib therapy. The adenovirus viral load became undetectable by the 180th day. With continuous remission, ruxolitinib was discontinued on the 137th day post-transplantation, and a 15-month follow-up examination showed no relapse. Conclusions: We present a case of adenovirus-related secondary HLH (sHLH) post-HSCT, which was effectively treated with ruxolitinib. Our case highlights the potential of ruxolitinib as a therapeutic option for patients with viral infections and sHLH. Nonetheless, the safety and efficacy of this innovative treatment should be evaluated in forthcoming large-scale clinical trials.

A degranulation assay using Vγ9Vδ2 T cells for the rapid diagnosis of familial hemophagocytic syndromes.

Introduction: Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening immune disorder characterized by uncontrolled lymphocyte and macrophage activation and a subsequent cytokine storm. The timely initiation of immunosuppressive treatment is crucial for survival. Methods: Here, we harnessed Vγ9Vδ2 T cell degranulation to develop a novel functional assay for the diagnosis of HLH. We compared the novel assay with the conventional natural killer (NK) cell stimulation method in terms of efficiency, specificity, and reliability. Our analysis involved 213 samples from 182 individuals, including 23 samples from 12 patients with degranulation deficiency (10 individuals with UNC13D deficiency, 1 with STXBP2 deficiency, and 1 with RAB27A deficiency). Results: While both tests exhibited 100% sensitivity, the Vγ9Vδ2 T cell degranulation assay showed a superior specificity of 86.2% (n=70) compared to the NK cell degranulation assay, which achieved 78.9% specificity (n=213). The Vγ9Vδ2 T cell degranulation assay offered simpler technical requirements and reduced labor intensity, leading to decreased susceptibility to errors with faster processing times. Discussion: This efficiency stemmed from the sole requirement of dissolving (E)-4-hydroxy-3-methyl-but-2-enyl pyrophosphate (HMBPP) powder, contrasting with the intricate maintenance of K562 cells necessary for the NK cell degranulation assay. With its diminished susceptibility to errors, we anticipate that the assay will require fewer repetitions of analysis, rendering it particularly well-suited for testing infants. Conclusion: The Vγ9Vδ2 T cell degranulation assay is a user-friendly, efficient diagnostic tool for HLH. It offers greater specificity, reliability, and practicality than established methods. We believe that our present findings will facilitate the prompt, accurate diagnosis of HLH and thus enable rapid treatment and better patient outcomes.

HLH and Recurrent EBV Lymphoma as the presenting manifestation of MAGT1 Deficiency: A Systematic Review of the Expanding Disease Spectrum.

Magnesium transporter 1 (MAGT1) gene loss-of-function variants lead to X-linked MAGT1 deficiency with increased susceptibility to EBV infection and N-glycosylation defect (XMEN), a condition with a variety of clinical and immunological effects. In addition, MAGT1 deficiency has been classified as a congenital disorder of glycosylation (CDG) due to its unique role in glycosylation of multiple substrates including NKG2D, necessary for viral protection. Due to the predisposition for EBV, this etiology has been linked with hemophagocytic lymphohistiocytosis (HLH), however only limited literature exists. Here we present a complex case with HLH and EBV-driven classic Hodgkin lymphoma (cHL) as the presenting manifestation of underlying immune defect. However, the patient's underlying immunodeficiency was not identified until his second recurrence of Hodgkin disease, recurrent episodes of Herpes Zoster, and after he had undergone autologous hematopoietic stem cell transplant (HSCT) for refractory Hodgkin lymphoma. This rare presentation of HLH and recurrent lymphomas without some of the classical immune deficiency manifestations of MAGT1 deficiency led us to review the literature for similar presentations and to report the evolving spectrum of disease in published literature. Our systematic review showcased that MAGT1 predisposes to multiple viruses (including EBV) and adds risk of viral-driven neoplasia. The roles of MAGT1 in the immune system and glycosylation were highlighted through the multiple organ dysfunction showcased by the previously validated Immune Deficiency and Dysregulation Activity (IDDA2.1) score and CDG-specific Nijmegen Pediatric CDG Rating Scale (NPCRS) score for the patient cohort in the systematic review.

Macrophage Activation Syndrome Presents as Initial Manifestation of Lupus in an Adult Female.

Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by the immune system erroneously attacking healthy tissues and organs. SLE has a wide variety of clinical presentations. The signs and symptoms of SLE are very well-known, though rare presentations could occur that require early clinical attention. Macrophage activation syndrome (MAS) is a severe and life-threatening condition in which the immune system becomes overactive, leading to the excessive stimulation and proliferation of immune cells. MAS can occur as a primary immune disorder, which is not very common. It can also happen secondary to a wide variety of pathological conditions, which include infections, malignancies, autoimmune, and rheumatologic disorders. In rare cases, SLE can present with overlapping features of MAS, further complicating the clinical picture, and may require specialized management. Early recognition and intervention of this overlap are essential for improving outcomes, as delayed diagnosis and treatment can lead to significant morbidity and mortality. Here, we present a case of a young adult female who was diagnosed with SLE with the initial presentation of MAS in the form of fever, splenomegaly, cytopenia, and hemophagocytosis.

Primary Bone Marrow Hodgkin's Lymphoma Debuting As Hemophagocytic Lymphohistiocytosis in a Patient With HIV.

The development of Hodgkin's lymphoma (HL) is a known complication in patients with human immunodeficiency virus (HIV) infection. Extranodal involvement, specifically primary bone marrow Hodgkin's lymphoma (PBMHL) is a rare manifestation that has been reported in HIV-positive patients and may represent a distinct entity from HIV-associated HL. We present a case of PBMHL presenting with hemophagocytic lymphohistiocytosis (HLH) in an HIV-positive patient. The 55-year-old male with HIV/AIDS presented with abdominal pain, diarrhea, and fever, leading to hospital admission. Despite initial treatment, he deteriorated, prompting re-admission and investigation revealing pancytopenia and elevated inflammatory markers, suggestive of HLH. Subsequent bone marrow biopsy unexpectedly revealed PBMHL. Treatment with HLH-directed therapy and the HLH-94 protocol resulted in significant clinical improvement. This case underscores the importance of recognizing atypical lymphoproliferative presentations in HIV/AIDS patients and the need for interdisciplinary collaboration in complex cases.

HLH-30/TFEB rewires the chaperone network to promote proteostasis under conditions of Coenzyme A and Iron-Sulfur Cluster Deficiency.

The maintenance of a properly folded proteome is critical for cellular function and organismal health, and its age-dependent collapse is associated with a wide range of diseases. Here, we find that despite the central role of Coenzyme A as a molecular cofactor in hundreds of cellular reactions, limiting Coenzyme A levels in C. elegans and in human cells, by inhibiting the conserved pantothenate kinase, promotes proteostasis. Impairment of the cytosolic iron-sulfur clusters formation pathway, which depends on Coenzyme A, similarly promotes proteostasis and acts in the same pathway. Proteostasis improvement by Coenzyme A/iron-sulfur cluster deficiencies are dependent on the conserved HLH-30/TFEB transcription factor. Strikingly, under these conditions, HLH-30 promotes proteostasis by potentiating the expression of select chaperone genes providing a chaperone-mediated proteostasis shield, rather than by its established role as an autophagy and lysosome biogenesis promoting factor. This reflects the versatile nature of this conserved transcription factor, that can transcriptionally activate a wide range of protein quality control mechanisms, including chaperones and stress response genes alongside autophagy and lysosome biogenesis genes. These results highlight TFEB as a key proteostasis-promoting transcription factor and underscore it and its upstream regulators as potential therapeutic targets in proteostasis-related diseases.

A Case Series on the Spectrum of Complications Observed in Kyasanur Forest Disease.

Background Kyasanur Forest Disease (KFD) has emerged as an important differential diagnosis of febrile illness for physicians caring for patients in the Western Ghats of South India over the last decade.  Aim This study seeks to familiarize physicians with the clinical presentation and the clinical, laboratory and imaging findings of the various complications of KFD. It also seeks to review the literature on the complications of KFD described. Material and methods This was a records-based retrospective study of the patients with KFD referred for tertiary care management to Government Medical College Kozhikode, Kerala over 11 years, from January 2013 to December 2023. Results A total of 12 case records were obtained and analysed. All the patients in this case series belonged to tribal ethnic groups enhancing its social significance. The complications of KFD (as calculated in the 11 patients for whom all the records were available) were altered sensorium (nine, 82%), persistent shock (seven, 64%), Acute Respiratory Distress Syndrome (ARDS)/pneumonitis (six, 55%), encephalitis (six, 55%), myocarditis (six, 55%), bleeding manifestations (six, 55%), hepatitis (six, 55%), acute kidney injury (four, 36%), rhabdomyolysis (three. 27%), hemophagocytic lymphohistiocytosis (HLH) (two, 18%), stress hyperglycaemia (two, 18%), pancreatitis (one, 9%), peritonitis (one, 9%). The case fatality rate in this series was 42%( n=5/12). An autopsy was done on one patient which showed congested and oedematous lungs with subpleural haemorrhage. Petechial haemorrhages were noted in the liver, spleen and kidney. The total leucocyte count was lower than 2500 c/mm3 in 10 (90%) patients. Out of the four patients in whom serum ferritin was tested, it was elevated (above 500 ng/ml) in all patients; and was above 1000 ng/ml in three patients. Hemophagocytic lymphohistiocytosis was diagnosed in two patients. This is a unique finding of our series. Both of these patients succumbed to the illness. A cerebrospinal fluid study was done in six patients and revealed normal values except in one patient. Troponin assays were done in seven patients and were positive in five patients indicating that myocarditis is a major contributor to shock, which is one of the commonest complications in KFD. Serum creatinine phosphokinase ranged from 656 to 23,000 U/L. Conclusions Altered sensorium was the most common alarming symptom that warrants referral to a higher centre. The major organ involvements that dominated the clinical presentation and course of illness were neurological complications, hypotension, significantly contributed by myocarditis and acute respiratory distress syndrome/pneumonitis. Encephalitis, myocarditis, ARDS and HLH were the major complications that caused mortality in our series. The elevated serum ferritin and the mortality associated with HLH described need further research to investigate the role of the macrophage system in the pathogenesis of severe KFD.

Mechanisms and management of CAR T toxicity.

Chimeric antigen receptor (CAR) T cell therapies have dramatically improved treatment outcomes for patients with relapsed or refractory B-cell acute lymphoblastic leukemia, large B-cell lymphoma, follicular lymphoma, mantle cell lymphoma, and multiple myeloma. Despite unprecedented efficacy, treatment with CAR T cell therapies can cause a multitude of adverse effects which require monitoring and management at specialized centers and contribute to morbidity and non-relapse mortality. Such toxicities include cytokine release syndrome, immune effector cell-associated neurotoxicity syndrome, neurotoxicity distinct from ICANS, immune effector cell-associated hemophagocytic lymphohistiocytosis-like syndrome, and immune effector cell-associated hematotoxicity that can lead to prolonged cytopenias and infectious complications. This review will discuss the current understanding of the underlying pathophysiologic mechanisms and provide guidelines for the grading and management of such toxicities.

Overcoming Diagnostic Challenges: A Rare Presentation of Primary Hemophagocytic Lymphohistiocytosis (HLH) in a Young Female and the Importance of Timely Recognition.

Hemophagocytic lymphohistiocytosis (HLH) is a severe life-threatening hematological disorder characterized by the dysregulation of the immune system and a hyperinflammatory response. Prompt treatment is crucial to prevent fatality. Although primarily affecting infants, HLH can also occur in children and adults. It is classified as primary and secondary, with primary HLH being genetic and predominantly affecting children. Secondary HLH is triggered by infections, malignancy, metabolic disorders, and rheumatological conditions. Diagnosis is based on the HLH-2004 criteria, considering clinical and laboratory parameters. Early diagnosis and treatment improve prognosis. Treatment follows the HLH-94 and HLH-2004 protocol and consists of eight weeks of induction therapy with cyclosporine, corticosteroids, and etoposide. This case describes a 26-year-old female diagnosed with HLH and successfully treated according to the protocol. The patient exhibited improvement and was discharged, demonstrating the importance of early diagnosis and appropriate management in adult HLH cases.

Serum proteomics reveals hemophagocytic lymphohistiocytosis-like phenotype in a subset of patients with multisystem inflammatory syndrome in children.

Children with Multisystem Inflammatory Syndrome in Children (MIS-C) can present with thrombocytopenia, which is a key feature of hemophagocytic lymphohistiocytosis (HLH). We hypothesized that thrombocytopenic MIS-C patients have more features of HLH. Clinical characteristics and routine laboratory parameters were collected from 228 MIS-C patients, of whom 85 (37%) were thrombocytopenic. Thrombocytopenic patients had increased ferritin levels; reduced leukocyte subsets; and elevated levels of ASAT and ALAT. Soluble IL-2RA was higher in thrombocytopenic children than in non-thrombocytopenic children. T-cell activation, TNF-alpha and IFN-gamma signaling markers were inversely correlated with thrombocyte levels, consistent with a more pronounced cytokine storm syndrome. Thrombocytopenia was not associated with severity of MIS-C and no pathogenic variants were identified in HLH-related genes. This suggests that thrombocytopenia in MIS-C is not a feature of a more severe disease phenotype, but the consequence of a distinct hyperinflammatory immunopathological process in a subset of children.

Navigating Complexity: A Case Study on Hemophagocytic Lymphohistiocytosis Diagnosis and Management Challenges.

Hemophagocytic lymphohistiocytosis (HLH) is a severe inflammatory disorder that affects multiple organ systems and carries a high risk of mortality if untreated. Treatment typically involves immune suppression with steroids and cytotoxic drugs. This case report details the evaluation and management of an adult female presenting with atypical symptoms, aims to improve awareness and understanding of HLH in adults, and emphasizes the urgency of timely diagnosis and intervention.

Case report: emapalumab treatment for a pediatric Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis (EBV-HLH) patient with cytokine storm enabling allogeneic hematopoietic cell transplantation.

Background: Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening syndrome characterized by excessive immune activation and inflammatory response. Conventional immunotherapy and molecular targeted drugs demonstrate varying efficacy. Cytokine storm, the primary pathogenic mechanism of HLH, is driven by interferon-gamma (IFN-γ), interleukin (IL)-2, IL-18, etc., in which IFN-γ plays a critical role in the development of the disease. Emapalumab, a potent IFN-γ inhibitor, effectively reduces the occurrence of cytokine storms in refractory and relapsed HLH. Case Description: A pediatric patient, 5 years old, female, with relapsed and refractory Epstein-Barr virus-associated HLH (EBV-HLH) showed no response to conventional chemotherapy or molecular-targeted drug treatment. However, after treatment with emapalumab, the patient achieved hematological remission. Subsequently, the patient underwent allogeneic hematopoietic cell transplantation (allo-HCT) and remains without HLH to date. Conclusions: To the best of our knowledge, this is the first case report using emapalumab to control EBV-HLH before HCT in mainland China. This case highlights the potential efficacy of emapalumab for treating relapsed and refractory EBV-HLH and providing a stable physical status for HCT. Further research is necessary to confirm the efficacy and safety of emapalumab in this setting.