HLH-2004: Diagnostic and therapeutic guidelines for hemophagocytic lymphohistiocytosis

SARS-CoV-2 reactivates fungal-associated Hemophagocytic lymphohistiocytosis: Case report and review of the literature

Hemophagocytic lymphohistiocytosis (HLH) is a rare disease characterized by the uncontrolled activation of the immune system, resulting in a high clinical mortality rate. A 56-year-old Chinese female presented at the emergency room with symptoms including fever, fatigue, nausea, vomiting, cough, shortness of breath, and chest tightness. Laboratory investigations demonstrated decreased levels of white blood cells, hemoglobin, and platelets while interleukin-6 and ferritin exhibited significant elevations. She was subsequently admitted to the hematology department, where she was diagnosed with HLH caused by a Candida infection. Following treatment with antifungal agents, glucocorticoids, antiemetics, diuretics, and hepatoprotective therapy, the patient's condition has shown improvement. However, after being infected with Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), the patient experienced a reactivation of HLH, resulting in a more severe clinical presentation and complications compared to the initial onset. Although the patient's condition improved after the administration of antiviral drugs, etoposide, glucocorticoids, cyclosporin, and intravenous immunoglobulin, this case highlights the possibility of disease reactivation during the recovery phase of HLH. This should raise the attention of medical professionals.

Clinical characterization of hemophagocytic lymphohistiocytosis caused by immune checkpoint inhibitors: a review of published cases

OBJECTIVE

An association exists between immune checkpoint inhibitors and hemophagocytic lymphohistiocytosis (HLH). Therefore, the main objective of this study was to collect data on this rare but potentially life-threatening immune-related adverse reaction to identify the medications that cause it, the clinical characteristics, and effective treatments.

METHODS

Literature in English and Chinese on immune checkpoint inhibitors causing HLH published from August 2014 to March 2024 was analyzed. Immune checkpoint inhibitors, immunotherapy, anti-PD-1, PD-L1 inhibitors, HLH, hemophagocytic lymphohistiocytosis, hemophagocytic syndrome keywords were used to find the literature on China Knowledge Network, Wanfang, PubMed and Emabase Databases.

RESULTS AND DISCUSSION

Twenty-four studies were included, with a total of 27 patients (18 males and 9 females) with a mean age of 58 years (range 26-86). The mean time to the onset of symptoms was 10.3 weeks (7 days-14 months). The main clinical characteristics were fever, cytopenia, splenomegaly, methemoglobinemia, hypofibrinogenemia, and bone marrow biopsy showed phagocytosis. Twenty-two patients improved after the treatment with steroids, cytokine blocking therapy and symptomatic treatment, four patients died, and one patient was not described.

CONCLUSION

HLH should be not underestimated as a potentially serious adverse effect of immune checkpoint inhibitors since appropriate treatments may save the life of patients.

Comprehensive evaluation of immune dysregulation in secondary hemophagocytic lymphohistiocytosis

Host immune dysfunction plays a crucial role in the onset, progression, and outcome of hemophagocytic lymphohistiocytosis (HLH). This study aimed to comprehensively evaluate the peripheral immune profiles in patients with newly diagnosed secondary hemophagocytic lymphohistiocytosis (sHLH), and explore their predictive value for patient prognosis. A total of 77 patients with sHLH were enrolled in this study, with 31 of them experiencing mortality. Flow cytometry was used to assess the percentages, absolute numbers, and phenotypes of lymphocyte subsets. Simultaneously, cytokine levels and routine laboratory indicators were also collected. In sHLH patients, lymphocyte subset absolute numbers were significantly impaired, accompanied by T cell hyperactivation, B cell hyperactivation, and increased plasmablast proliferation. Prognostic analysis revealed that lower CD8+ T cell percentages, elevated APTT, IL-6, IL-10 levels, and increased CD4+CD28null T cell proportions were associated with poor patient outcomes. The study demonstrates dysregulation in the counts and phenotypes of lymphocyte subsets in sHLH patients. Several key factors, including IL-6, IL-10, APTT, and various T cell percentages, have potential as prognostic markers and therapeutic targets in sHLH.

A differential diagnosis method for systemic CAEBV and the prospect of EBV-related immune cell markers via flow cytometry

Chronic active Epstein-Barr virus (CAEBV) infection of the T-cell or Natural killer (NK)-cell type, systemic form (systemic CAEBV or sCAEBV) was defined by the WHO in 2017 as an EBV-related lymphoproliferative disorder and is listed as an EBV-positive T-cell and NK-cell proliferation. The clinical manifestations and prognoses are heterogeneous. This makes systemic CAEBV indistinguishable from other EBV-positive T-cell and NK-cell proliferations. Early diagnosis of systemic CAEBV and early hematopoietic stem cell transplantation can improve patient prognosis. At present, the diagnosis of systemic CAEBV relies mainly on age, clinical manifestations, and cell lineage, incurring missed diagnosis, misdiagnosis, long diagnosis time, and inability to identify high-risk systemic CAEBV early. The diagnostic methods for systemic CAEBV are complicated and lack systematic description. The recent development of diagnostic procedures, including molecular biological and immunological techniques such as flow cytometry, has provided us with the ability to better understand the proliferation of other EBV-positive T cells and NK cells, but there is no definitive review of their value in diagnosing systemic CAEBV. This article summarizes the recent progress in systemic CAEBV differential diagnosis and the prospects of flow cytometry.

A need for greater awareness: a mixed methods study of patient and healthcare professional perspectives on the diagnosis journey for haemophagocytic lymphohistiocytosis (HLH)

OBJECTIVES

Our aim was to better understand and raise awareness of the diagnosis journey and quantify any barriers for timely diagnosis of haemophagocytic lymphohistiocytosis (HLH), to support patients' struggle with diagnosis and reduce time to diagnosis.

METHODS

Patients diagnosed with, or caregivers for those diagnosed with primary or secondary HLH and physicians involved in the treatment of HLH were recruited. Quantitative interviews were undertaken with patients/caregivers to quantify key elements of the diagnosis journey, followed by qualitative interviews with participants. Interviews took place between March-May 2021.

RESULTS

Thirty-three patients/caregivers and nine physicians took part in this mixed methods study. Lack of physician awareness of HLH was a common frustration for patients/caregivers, causing delayed diagnosis. All physicians indicated bone-marrow testing is a key step in the diagnosis process, and some patients/caregivers had frustrations around testing. Emergency care doctors, although not usually involved in the diagnosis process, were among the most-seen specialists by patients/caregivers. Patients/caregivers suggested potential improvements in available information, such as providing information on treatment options and condition management.

DISCUSSION

Patients/caregivers and physicians agreed on the need to raise overall awareness of HLH signs/symptoms among priority groups of physicians to recognise how signs/symptoms can progress and develop. Improvements in the testing process and communication would directly impact the speed of diagnosis and support patients/caregivers during the diagnostic journey, respectively.

CONCLUSION

Raising awareness of key issues, such as signs/symptoms, tests and diagnostic procedures, and improved communication and support for patients/caregivers, are key to speeding up HLH diagnosis and improving outcomes.

Unexplained splenomegaly as a diagnostic marker for a rare but severe disease with an innovative and highly effective new treatment option: A case report

Acid Sphingomyelinase Deficiency (ASMD) is a lysosomal storage disorder that can lead to severe complications if not promptly treated. This case aims to highlight the critical importance of early awareness of ASMD and to introduce, for the first time in the literature, a new and highly effective treatment option for children.

A MASsive attack: a pediatric case of macrophage activation syndrome complicated by DIC as an onset of systemic juvenile idiopathic arthritis successfully treated with anakinra and review of the literature

Macrophage activation syndrome (MAS) is one of the most severe complications of systemic juvenile idiopathic arthritis (sJIA). Around 10% of patients with sJIA exhibit systemic symptoms accompanied by macrophage activation syndrome (MAS), but it may occur subclinically in another 30-40%. In this article, we present a case of a 3-year-old girl diagnosed with sever MAS as an onset of sJIA complicated by disseminated intravascular coagulation (DIC). First symptoms of sJIA were observed about 5 months before setting the diagnose, and it was resembling urticaria. A comprehensive allergological diagnostics were conducted, but no cause for the skin changes was identified. A few weeks before admission to the hospital, the girl was presented with a high fever. During the hospital stay, viral, bacterial, and fungal infections were ruled out. However, the findings indicated significantly elevated markers of inflammation (ferritin, CRP, ESR) in the conducted tests. Meanwhile, swelling of the feet and ankle joints was also observed. Based on Ravelli criteria, we set the diagnosis of MAS in a course of sJIA. We implemented treatment with steroid pulses, followed by cyclosporine; however, her clinical condition did not improve. Despite intensive treatment, skin petechiae were observed twice, and laboratory tests revealed a very high INR along with an extremely low level of fibrinogen. The patient required multiple plasma transfusions and clotting factor administrations. Due to the severe condition of the girl, we initiated biological treatment with anakinra, after which the child's condition gradually improved. In this case, we want to present how dynamic and life-threatening the course of MAS can be. In the discussion, we are also comparing our approach and the applied treatment with the currently available knowledge.

Accelerated phase development in a late-onset adolescent Chediak-Higashi syndrome patient caused by compound novel LYST mutations in the setting of SARS-CoV-2 infection

Chediak-Higashi syndrome (CHS) is a rare autosomal recessive genetic disorder characterized by severe immunodeficiency, albinism and coagulation deficiency. Mostly diagnosed in early childhood, this devastating condition is associated with lysosomal abnormalities attributed to the absence or impaired function of lysosomal trafficking regulator caused by mutations in the CHS1/LYST gene. In current study, we report a case of late-onset CHS caused by two novel compound heterozygous CHS1/LYST mutations: c.8407C > T, leading to early termination of translation at residue Gln2803 (p. Gln2803Ter), and a small deletion c. 4020_4031del, resulting in an in-frame deletion of three amino acid residues (p. Asp1343_Val1346del). Both variants retain a large part of the CHS/LYST protein, particularly p. Asp1343_Val1346del, which preserves critical functional BEACH and WD40 domains in the C terminal, potentially maintaining residual activity and alleviating patient symptoms. The timeline of SARS-CoV-2 infection and rapid symptom progression suggests that the viral infection may have trigger the accelerated phase development leading to a poor prognosis.

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.

A rare case report of hemophagocytic lymphohistiocytosis secondary to pure eythroid leukemia in a person living with HIV

Pure erythroid leukemia (AML-M6) is a rare variant of acute myeloid leukemia (AML) with predominant erythroid lineage proliferation. The incidence of AIDS defining cancers including Kaposi sarcoma and non-Hodgkins lymphoma are on declining trends due to effective use of HAART (Highly Active Antiretroviral Therapy). Correspondingly, there have been increasing cases of leukemia in persons living with HIV. Our case is a 43 years old male living with HIV who was admitted with high grade fever and mucosal bleeds. On examination, he had periorbital swelling and ecchymosis with hepatosplenomegaly. The laboratory investigations revealed bicytopenia with high ferritin, low fibrinogen and hypertriglyceridemia. A diagnosis of hemophagocytic lymphohistiocytosis (HLH) with H score of 222 was made. Bone marrow examination revealed hypercellular marrow with more than 80% cells of erythroid lineage with 47% proerythroblasts. Suggesting pure erythroid leukemia (AML-M6). This diagnosis with secondary HLH carries a very poor prognosis in persons living with HIV.

Successful management of infection and macrophage activation syndrome patient using low-dose etoposide: A case report

BACKGROUND

Macrophage activation syndrome (MAS), a sub-type of hemophagocytic lymphohistiocytosis (HLH) secondary to autoimmune rheumatic diseases, is a critical and potentially fatal condition characterized by an excessive inflammatory response. Despite the established efficacy of the HLH-2004 guideline in diagnosing and treating HLH over the years, ongoing discussion persists regarding its application, especially for HLH secondary to complicated conditions, such as autoimmune rheumatic diseases combined with severe infection. Etoposide (VP-16), a topoisomerase II inhibitor that effectively induces DNA damage and subsequent apoptosis in hyperactivated immune cells, has been widely used for the treatment of HLH. However, its suppressive effect on immune system may also cause potential exacerbation of infection in autoimmune rheumatic disease-induced HLH patients complicated with severe infection. Therefore, the use of VP-16 in such cases was inconclusive.

CASE SUMMARY

In this case study, we propose a potentially effective strategy for managing a patient diagnosed with secondary HLH complicated with systemic lupus erythematosus (SLE) and chronic coronavirus disease 2019 infection. Our approach involves early administration of low-dose VP-16 (100 mg twice a week, 300 mg in total), combined with methylprednisolone, cyclophosphamide, and cyclosporine A. The administration of etoposide effectively led to improvements in various indices of HLH.

CONCLUSION

Low dose etoposide proves to be an effective approach in alleviating HLH while mitigating the risk of infection.

Pre-diagnostic trajectory of pediatric hemophagocytic lymphohistiocytosis: observations from hematological and hepatic parameters

Understanding the early features and characteristics of hemophagocytic lymphohistiocytosis (HLH) is essential for identifying high-risk individuals and also providing valuable pathological insights. This study aims to investigate the characteristics and trends of blood and hepatic parameters before an HLH diagnosis was established. Longitudinal hematological and hepatic test results from pediatric patients with HLH and an age- and sex-matched control group were analyzed. According to the length of time between hospital admission and the establishment of the HLH diagnosis, the HLH cases were divided into early-onset (≤ 7 days) and late-onset (> 7days) groups. Among the 229 pediatric HLH patients, the length of time between hospital admission and the establishment of an HLH diagnosis ranged from 0 to 41 days (median = 4 days). Over 80% of pediatric HLH patients presented abnormal laboratory results for aspartate aminotransferase (AST), triglycerides, lactate dehydrogenase (LDH), and hemoglobin at admission. The abnormal rates in the initial platelet count, neutrophil count, and fibrinogen tests were 67.3%, 48.3%, and 52.2%, respectively. The initial test results for AST, alanine aminotransferase (ALT), LDH, serum sodium, and albumin showed AUCs > 80% for discriminating early-onset HLH. For the discrimination of late-onset HLH, the performance of initial test results was poor. To conclude, abnormalities in AST, triglycerides, LDH, and hemoglobin are early presentations of pediatric HLH; platelet, neutrophil, and fibrinogen levels may become abnormal at a relatively late stage of the HLH disease trajectory; and the initial test results for AST, ALT, LDH, serum sodium, and albumin can be used to identify suspected early-onset HLH.

Diagnostic accuracy of bone marrow blood evaluation in haemophagocytic lymphohistiocytosis paediatric patients

INTRODUCTION

Haemophagocytic lymphohistiocytosis (HLH) is a rare and serious immunological syndrome that involves a strong activation of cytotoxic T lymphocytes and macrophages. HLH determines a cytokine-mediated tissue injury with a contemporary multi-organ failure and a high fatality rate.

MATERIAL AND METHODS

A retrospective study was performed considering the medical records of paediatric patients who underwent a bone marrow aspirate for suspect HLH. The biomarkers evaluated were among those included in the HLH-2004. Lactate dehydrogenase (LD) was also evaluated. Haemophagocytosis was evaluated in bone marrow blood smear slides.

RESULTS

Enrolled were 11 patients included in the HLH group and 8 patients as controls. Haemoglobin and fibrinogen resulted lower in HLH patients than in controls, while blood triglycerides, serum ferritin and LD resulted increased. Blood triglycerides and fibrinogen discriminated HLH cases perfectly, with a sensitivity and specificity of 100%. Ferritin had a sensitivity of 100% and a specificity of 83% (cut off ≥3,721 µg/L) and LD of 73% and of 100% (the cut off ≥1,903 U/L). Haemoglobin was found to have a sensitivity of 75% and a specificity of 100% (cut off ≤ 96 g/L). Total haemophagocytes cell counts were not different between patients and controls. Only the increased number of phagocytized nucleated red blood cells (NRBC) was found to be significantly increased in the patients. Erythrocytes phagocytosis (≥4/1,000 cells) only tended towards significance.

CONCLUSIONS

The blood biomarkers showed better diagnostic performance than the morphological evaluation. Among the different cell lineages engulfed by haemophagocytes, the best diagnostic performance was obtained by phagocytosed mature erythrocytes and immature nucleated erythrocytes.

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

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

METHODS

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

RESULTS

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

CONCLUSION

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

Cluster analysis defines four groups of Japanese patients with adult-onset Still's disease

OBJECTIVES

To define groups and characterize differences in the prognosis of patients with adult-onset Still's disease (AOSD).

METHODS

We performed a retrospective cohort study. Patients with AOSD were grouped using hierarchical unsupervised cluster analysis according to age, sex, clinical features, and laboratory data. The primary endpoints were overall survival and drug-free remission rate.

RESULTS

A total of 153 patients with AOSD were placed into four clusters. Those in Cluster 1 had a young onset, tended to be female, and had fewer complications and moderate ferritin concentrations. Those in Cluster 2 had a young onset and had more complications and higher ferritin concentrations. Those in Cluster 3 had a young onset, tended to be male, and had no lymphadenopathy and fewer complications. Those in Cluster 4 had an older onset, tended to be female, and had more complications and higher ferritin concentrations. Overall survival tended to be lower (P = .0539) in Cluster 4, and drug-free remission was higher in Clusters 1, 2, and 3 [hazard ratios (HRs) 2.19, 3.37, and 3.62 vs. Cluster 4, respectively].

CONCLUSIONS

Four groups of AOSD that have distinct clinical manifestations, ferritin concentrations, severity, and drug-free remission rate were identified, which were lowest in Cluster 4.

Functional role of UNC13D in immune diseases and its therapeutic applications

UNC13 family (also known as Munc13) proteins are evolutionarily conserved proteins involved in the rapid and regulated secretion of vesicles, including synaptic vesicles and cytotoxic granules. Fast and regulated secretion at the neuronal and immunological synapses requires multiple steps, from the biogenesis of vesicles to membrane fusion, and a complex array of proteins for each step. Defects at these steps can lead to various genetic disorders. Recent studies have shown multiple roles of UNC13D in the secretion of cytotoxic granules by immune cells. Here, the molecular structure and detailed roles of UNC13D in the biogenesis, tethering, and priming of cytotoxic vesicles and in endoplasmic reticulum are summarized. Moreover, its association with immune diseases, including familial hemophagocytic lymphohistiocytosis type 3, macrophage activation syndrome, juvenile idiopathic arthritis, and autoimmune lymphoproliferative syndrome, is reviewed. Finally, the therapeutic application of CRISPR/Cas9-based gene therapy for genetic diseases is introduced.

Myeloma-associated hemophagocytic lymphohistiocytosis - A comprehensive case study and a novel chemotherapy-free approach with anakinra

Hemophagocytic lymphohistiocytosis (HLH) is an immune response syndrome characterized by excessive inflammation and tissue destruction. A limited number of cases involving HLH patients with concomitant multiple myeloma (MM), leading to significant mortality, have been documented, underscoring the importance of timely diagnosis. We present the case of a 78-year-old previously healthy male admitted to our hospital with a newly diagnosed MM. Subsequently, he was diagnosed with HLH and received treatment with anakinra, intravenous immunoglobulin, and dexamethasone. This case report highlights the unique aspect of being the first documented instance of myeloma-associated HLH treated with anakinra.

Marked hyperferritinemia in critically ill cancer patients

OBJECTIVES

To investigate characteristics and outcomes of critically ill cancer patients with marked hyperferritinemia.

METHODS

A single-center retrospective analysis comprising cancer patients with a ferritin level >10.000 μg/L treated in the intensive care unit (ICU) between 2012 and 2022 was conducted.

RESULTS

A total of 117 patients were included in the analysis. The median age was 59 years (range: 15-86 years). Females accounted for 48% of cases. 90% of patients had a hematologic malignancy. The median maximum ferritin level was 27.349 μg/L (range: 10.300-426.073 μg/L). The diagnostic criteria of septic shock were fulfilled in 51% of cases; 31% of patients had hemophagocytic lymphohistiocytosis (HLH) according to the HLH-2004 criteria. Mechanical ventilation, renal replacement therapy and the use of vasopressors were necessary in 59%, 35% and 70% of cases, respectively. The ICU, hospital, 90-day and 1-year survival rates were 33.3%, 23.1%, 23.7% and 11.7%. Patients with septic shock had a worse survival than those without septic shock (p = .001); the survival of patients who fulfilled the HLH-2004 criteria did not differ from those who did not (p = .88).

CONCLUSION

Critically ill cancer patients with marked hyperferritinemia have poor outcomes. The present data may help to make informed decisions for this patient group.

Predicting relapsed/refractory disease in childhood hemophagocytic lymphohistiocytosis based on clinical features at diagnosis: A 13-year single-institute retrospective study in Thailand

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening disease. Relapsed/refractory disease is the main cause of death. This study aims to determine the prognostic indicators for relapsed/refractory disease in childhood HLH (R/R HLH). Infants and children under 18 years of age who were diagnosed with HLH according to HLH-2004 criteria, MAS-HLH criteria for rheumatologic diseases, or H-score undergoing treatment in Chiang Mai University hospital between 2010 and 2022 were included. Demographic data, clinical characteristics, and laboratory parameters were retrospectively reviewed. Out of 86 childhood HLH cases, 30 patients (34.9%) experienced R/R HLH. All patients with primary HLH developed R/R HLH. The most common form of secondary HLH was infection-associated hemophagocytic syndrome (IAHS), comprising 43 cases. Of these, 37.2% had relapsed or refractory disease. Univariable analysis identified several potential risk factors for R/R HLH, including younger age, severe disease status, higher HLH-2004 criteria scores, higher H-scores, overt DIC, higher pSOFA scores, and increased levels of aspartate aminotransferase, total bilirubin, and direct bilirubin. Multivariable logistic regression analysis revealed that a pSOFA score of ≥ 8 and age < 3 years were independent risk factors for R/R HLH, with adjusted odds ratios of 6.35 (95% confidence interval [CI], 1.18-34.19; P = 0.032) and 3.62 (95% CI, 1.04-12.63; P = 0.044), respectively. Children with HLH who have a pSOFA score of ≥ 8, or are younger than 3 years, are at a higher risk of relapsed or refractory disease. Further evaluation of management strategies in this context is warranted.

Biomarkers in Pediatric Hemophagocytic Lymphohistiocytosis With Central Nervous System Involvement: A Cohort Study

BACKGROUND

The aim of this study was to analyze the clinical significance of cerebrospinal fluid (CSF) cytokines in hemophagocytic lymphohistiocytosis associated with central nervous system (CNS-HLH).

METHODS

CSF cytokine levels, including interferon (IFN)-γ, soluble CD25 (sCD25), interleukin (IL)-6, IL-10, IL-18, and CXCL9 were measured at disease onset and during the treatment. Five newly diagnosed patients with demyelination disease were enrolled for comparison.

RESULTS

Sixty-five samples from 36 patients (13 in the CNS group and 23 in the non-CNS group) were detected. Levels of CSF IFN-γ, sCD25, IL-10, IL-18, and CXCL9 in the CNS group were higher than those in the non-CNS group ( P =0.038, <0.001, <0.001, 0.005, and <0.001), and levels of CSF sCD25, IL-10, IL-18, and CXCL9 in the CNS group were higher than those in the demyelination group ( P =0.001, 0.008, 0.004, and 0.003). There was no significant difference in IL-6 levels among the 3 groups ( P =0.339). CSF IFN-γ, sCD25, IL-10, IL-18, and CXCL9 could assist in diagnosing CNS-HLH. The diagnostic efficiency of CSF sCD25, IL-10, and CXCL9 was better, with a cutoff value of 154.64, 1.655, and 19.54 pg/mL, respectively. The area under the curve was >0.9, with sensitivity and specificity >80%. Correlation analysis suggested that in the CNS group, IFN-γ levels in CSF and serum correlated positively ( R =0.459, P =0.007), while there was no correlation between CSF CXCL9 and serum IFN-γ ( P =0.915).

CONCLUSIONS

CSF IFN-γ, sCD25, IL-10, IL-18, and CXCL9 levels were significantly higher in HLH patients with CNS involvement than those without and could predict HLH patients with CNS involvement. CSF CXCL9 might be a more sensitive biomarker to CNS-HLH than IFN-γ, while CSF IL-6 does not seem to play a vital role.

Griscelli syndrome: a diagnostic challenge of a rare disease: a case report

Introduction

Griscelli syndrome (GS) is a rare autosomal recessive genetic disorder that primarily manifests as hair and skin hypopigmentation, with three types differentiated by their specific genetic defects as well as by their clinical features. Clinically, GS type 1 is characterized by early neurological alterations, while GS type 2 is characterized by immunodeficiency and could present with neurological symptoms, and type 3 is characterized by a chromosomal anomaly without a specific clinical profile besides hypopigmentation. This article details the challenges faced in the diagnosis of a patient with GS who presents with neurological symptoms followed by immunological deficits.

Case presentation

A 7-month-old female presented with complaints of developmental delay following an otitis media infection. Upon examination, she exhibited signs of psychomotor developmental regression and had pale bronze skin and silvery-gray hair, as well as hepatosplenomegaly. The examination of her hair shaft revealed a pattern consistent with GS. During her hospitalization, the patient developed an intermittent fever and signs of hemophagocytic lymphohistiocytosis (HLH). She subsequently developed recurrent seizures treated with phenytoin and Aciclovir. Shortly she succumbed to respiratory distress syndrome and multisystem failure.

Discussion

The presence of HLH confirms the type of GS. However, in some cases, the HLH criteria could not be fulfilled, presenting a diagnostic challenge.

Conclusion

The genetic examination is the only way to differentiate GS type 1 from type 2. However, when it is not available, the presence of specific symptoms and features may assist in the classification. Furthermore, treatments should be administered when GS type 2 is suspected since they have the potential to improve life quality through treating HLH, delaying and altering the neurological symptoms.

Emapalumab as a therapeutic intervention for Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis: A case series

RATIONALE

Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis (EBV-HLH) is characterized by a severe cytokine storm, heightened inflammatory response, and immune-mediated damage to tissues and organs. Standard treatment protocols for hemophagocytic lymphohistiocytosis often fall short in effectively controlling EBV-HLH, leading to a need for novel therapeutic options. Emapalumab, a monoclonal antibody targeting interferon-gamma, has shown promise due to its targeted cytokine modulation capabilities and favorable safety profile. This study aimed to evaluate the efficacy and safety of emapalumab in pediatric patients with EBV-HLH.

PATIENT CONCERNS

The case series involved 4 pediatric patients diagnosed with EBV-HLH who did not achieve disease control despite receiving comprehensive treatment.

DIAGNOSES

All 4 pediatric patients were diagnosed with EBV-HLH.

INTERVENTIONS

Emapalumab was introduced as an adjunctive therapeutic intervention alongside the HLH-94 or L-DEP regimens for these patients.

OUTCOMES

Among the 4 patients, 1 experienced severe multiorgan dysfunction and opted to discontinue therapy. The remaining 3 patients showed controlled disease progression with significant clinical improvements following emapalumab administration. These improvements included reduced levels of inflammatory markers, normalization of blood counts and liver function, and decreased Epstein-Barr virus viral load.

LESSONS

The findings suggest that emapalumab may be an effective and safe treatment option for pediatric EBV-HLH. However, further research is necessary to confirm these outcomes, especially in critically ill patients.

Transplantation for immune dysregulatory disorders: current themes and future expectations

PURPOSE OF REVIEW

Primary immune regulatory disorders (PIRDs) are an increasing indication for hematopoietic stem cell transplant (HCT) in pediatric patients. Here, we provide an updated overview of HCT for PIRDs, and discuss future avenues for improvement in outcomes.

RECENT FINDINGS

There are now more than 50 described monogenic PIRDs, which impact all aspects of immune tolerance, regulation, and suppression. Disease characteristics are highly variable, and HCT remains the only option for cure. We review advances in targeted therapies for individual PIRDs, which have significantly improved outcomes and the ability to safely bridge to transplant. Additionally, advances in GVHD prevention, graft manipulation, personalized conditioning regimens, and supportive care have all increased survival after HCT. The high inflammatory state increases the risk of nonengraftment, rejection, and autologous reconstitution. Therapy to reduce the inflammatory state may further improve outcomes. In addition, although younger patients with fewer comorbidities have better outcomes, the clinical courses of these diseases may be extremely variable thereby complicating the decision to proceed to HCT.

SUMMARY

HCT for PIRDs is a growing consideration in cell therapy. Yet, there remain significant gaps in our understanding of which patients this curative therapy could benefit the most. Here, we review the current data supporting HCT for PIRDs as well as areas for future improvement.

Indices and ferritin level that predict organ involvement in adult-onset Still's disease

Aim: The aim of the study is to evaluate whether C-reactive protein to albumin ratio (CAR), lactate dehydrogenase to albumin ratio (LAR), ferritin to erythrocyte sedimentation rate ratio (FER), systemic immune-inflammation index (SII), prognostic nutritional index (PNI) indices and ferritin level can predict organ involvement in adult-onset Still's disease (AOSD) patients.Methods: This study was planned as a cross-sectional study. Univariate and multivariate logistic regression analyses were performed to evaluate the usefulness of ferritin level and inflammatory indices in defining organ involvement.Results: Sixty-one patients diagnosed with AOSD were included in this study. Multivariate logistic regression analyzes showed that LAR (OR 1.028, 95% CI: 1.011-1.044) (p = 0.001) index predicted lymphadenopathy involvement, CAR (OR 1.249, 95% CI: 1.087-1.435) (p = 0.002) index predicted hepatomegaly involvement, ferritin level (OR 1.004, 95% CI: 1.001-1.008) (p = 0.007) predicted splenomegaly involvement, FER (OR 1.085, 95% CI: 1.012-1.164) (p = 0.021) and PNI (OR 0.271, 95% CI: 1.132-0.553) (p < 0.001) index predicted the occurrence of serositis.Conclusion: This study showed that ferritin level, CAR, FER, PNI and LAR markers may predict organ involvement at diagnosis in AOSD patients.

Machine Learning of Laboratory Data in Predicting 30-Day Mortality for Adult Hemophagocytic Lymphohistiocytosis

BACKGROUND

Hemophagocytic Lymphohistiocytosis (HLH) carries a high mortality rate. Current existing risk-evaluation methodologies fall short and improved predictive methods are needed. This study aimed to forecast 30-day mortality in adult HLH patients using 11 distinct machine learning (ML) algorithms.

METHODS

A retrospective analysis on 431 adult HLH patients from January 2015 to September 2021 was conducted. Feature selection was executed using the least absolute shrinkage and selection operator. We employed 11 ML algorithms to create prediction models. The area under the curve (AUC), sensitivity, specificity, positive predictive value, negative predictive value, F1 score, calibration curve and decision curve analysis were used to evaluate these models. We assessed feature importance using the SHapley Additive exPlanation (SHAP) approach.

RESULTS

Seven independent predictors emerged as the most valuable features. An AUC between 0.65 and 1.00 was noted among the eleven ML algorithms. The gradient boosting decision tree (GBDT) algorithms demonstrated the most optimal performance (1.00 in the training cohort and 0.80 in the validation cohort). By employing the SHAP method, we identified the variables that contributed to the model and their correlation with 30-day mortality. The AUC of the GBDT algorithms was the highest when using the top 4 (ferritin, UREA, age and thrombin time (TT)) features, reaching 0.99 in the training cohort and 0.83 in the validation cohort. Additionally, we developed a web-based calculator to estimate the risk of 30-day mortality.

CONCLUSIONS

With GBDT algorithms applied to laboratory data, accurate prediction of 30-day mortality is achievable. Integrating these algorithms into clinical practice could potentially improve 30-day outcomes.

Immune response to viscerotropic Leishmania: a comprehensive review

L. donovani and L. infantum infections are associated with a broad clinical spectrum, ranging from asymptomatic cases to visceral leishmaniasis (VL) with high mortality rates. Clinical manifestations such as post-kala-azar dermal leishmaniasis (PKDL) and visceral leishmaniasis-associated hemophagocytic lymphohistiocytosis-mimic (VL-associated HLH-mimic) further contribute to the diversity of clinical manifestations. These clinical variations are intricately influenced by the complex interplay between the host's immune response and the parasite's escape mechanisms. This narrative review aims to elucidate the underlying immunological mechanisms associated with each clinical manifestation, drawing from published literature within the last 5 years. Specific attention is directed toward viscerotropic Leishmania sinfection in patients with inborn errors of immunity and acquired immunodeficiencies. In VL, parasites exploit various immune evasion mechanisms, including immune checkpoints, leading to a predominantly anti-inflammatory environment that favors parasite survival. Conversely, nearly 70% of individuals are capable of mounting an effective pro-inflammatory immune response, forming granulomas that contain the parasites. Despite this, some patients may experience reactivation of the disease upon immunosuppression, challenging current understandings of parasite eradication. Individuals living with HIV and those with inborn errors of immunity present a more severe course of infection, often with higher relapse rates. Therefore, it is crucial to exclude both primary and acquired immune deficiencies in patients presenting disease relapse and VL-associated HLH-mimic. The distinction between VL and HLH can be challenging due to clinical similarities, suggesting that the nosological entity known as VL-associated HLH may represent a severe presentation of symptomatic VL and it should be considered more accurate referring to this condition as VL-associated HLH-mimic. Consequently, excluding VL in patients presenting with HLH is essential, as appropriate antimicrobial therapy can reverse immune dysregulation. A comprehensive understanding of the immune-host interaction underlying Leishmania infection is crucial for formulating effective treatment and preventive strategies to mitigate the disease burden.

Genetic profiles and clinical features in subcutaneous panniculitis-like T-cell lymphomas

Subcutaneous panniculitis-like T-cell lymphoma (SPTCL) is a rare peripheral T-cell lymphoma characterized by cutaneous lesions and immunologic manifestations. The five-year survival rate of SPTCL has been reported to be over 80%, indicating a favorable prognosis. Recent studies have uncovered recurrent germline variants in HAVCR2, encoding an immunomodulator. In this study, we integrated whole-exome sequencing data from 60 samples collected from 36 SPTCL patients, encompassing six patients of our cohort and 30 patients of publicly available data. We identified 138 somatic mutations in skin tumors of 24 patients and HAVCR2 germline mutations in 23 of 29 patients. HAVCR2 p.Tyr82Cys mutations were identified in four of six Japanese patients. During the clinical courses of four patients, cyclophosphamide, hydroxydaunomycin, vincristine, and prednisone were administered to all patients, but it resulted in incomplete responses in all four patients. However, disease conditions of all patients remained stable with additional treatment, including autologous peripheral blood stem cell transplantation. Over a 7.5-year median follow-up, one patient developed autoimmune-related diseases, while one developed other hematological malignancy, resulting in death. To our knowledge, this is the first report of recurrent HAVCR2 germline mutations in Japanese patients, suggesting the necessity for long-term follow-up.

Systemic T-cell activation and IFN-γ activity in indeterminate severe hepatitis are reminiscent of hemophagocytic lymphohistiocytosis: Implications for T-cell- and IFN-γ-directed therapies

BACKGROUND

Severe hepatitis cases in children are increasingly recognized, but the exact etiology remains unknown in a significant proportion of patients. Cases of indeterminate severe hepatitis (iSH) may progress to indeterminate pediatric acute liver failure (iPALF), so understanding its immunobiology is critical to preventing disease progression. Hemophagocytic lymphohistiocytosis (HLH) is a systemic hyperinflammatory disorder associated with T-cell and macrophage activation with liver injury.

OBJECTIVES

We hypothesized that a high proportion of patients with iSH demonstrate systemic T-cell activation similar to HLH before developing iPALF and that the degree of T-cell activation in iSH might correlate with outcomes.

METHODS

From 2019 to 2022, 14 patients with iSH and 7 patients with PALF of known, nonimmune etiology were prospectively enrolled. We compared immune signatures of iSH, HLH, known PALF, and healthy controls.

RESULTS

We found that patients with iSH have increased CD8+ T-cell activation and high IFN-γ activity similar to HLH. The amplitude of CD8+ T-cell activation was predictive of iSH progression to iPALF. We also found that in patients with iSH, ferritin had only modest elevation. However, the ratio of age-normalized plasma soluble IL-2 receptor to ferritin level can distinguish iSH from known PALF and HLH. As proof of concept, we report that in 3 patients with steroid-refractory iSH, emapalumab, an IFN-γ blocking antibody used in combination with steroids, improved liver function and may have prevented progression to PALF.

CONCLUSIONS

Flow-based T-cell activation markers could help in early identification and risk stratification for targeted intervention in patients with iSH.

Hyperferritinemia Screening to Aid Identification and Differentiation of Patients with Hyperinflammatory Disorders

High ferritin is an important and sensitive biomarker for the various forms of 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 at UPMC Children's Hospital where serum ferritin > 1000 ng/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 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.

Interleukin-1-mediated hyperinflammation in XIAP deficiency is associated with defective autophagy

ABSTRACT

Deficiency of X-linked inhibitor of apoptosis protein (XIAP) is a rare genetic condition that can present with recurrent episodes of hemophagocytic lymphohistiocytosis (HLH), though the exact mechanisms leading to this hyperinflammatory disorder are unclear. Understanding its biology is critical to developing targeted therapies for this potentially fatal disease. Here, we report on a novel multiexonic intragenic duplication leading to XIAP deficiency with recurrent HLH that demonstrated complete response to interleukin (IL)-1β blockade. We further demonstrate using both primary patient cells and genetically modified THP-1 monocyte cell lines that, contrary to what has previously been shown in mouse cells, XIAP-deficient human macrophages do not produce excess IL-1β when stimulated under standard conditions. Instead, nucleotide-binding oligomerization domain-like receptor family pyrin domain containing 3 (NLRP3) inflammasome-mediated hyperproduction of IL-1β is observed only when the XIAP-deficient cells are stimulated under autophagy-promoting conditions and this correlates with defective autophagic flux as measured by decreased accumulation of the early autophagy marker LC3-II. This work, therefore, highlights IL-1β blockade as a therapeutic option for patients with XIAP deficiency experiencing recurrent HLH and identifies a critical role for XIAP in promoting autophagy as a means of limiting IL-1β-mediated hyperinflammation during periods of cellular stress.

Into the storm: the imbalance in the yin-yang immune response as the commonality of cytokine storm syndromes

There is a continuous cycle of activation and contraction in the immune response against pathogens and other threats to human health in life. This intrinsic yin-yang of the immune response ensures that inflammatory processes can be appropriately controlled once that threat has been resolved, preventing unnecessary tissue and organ damage. Various factors may contribute to a state of perpetual immune activation, leading to a failure to undergo immune contraction and development of cytokine storm syndromes. A literature review was performed to consider how the trajectory of the immune response in certain individuals leads to cytokine storm, hyperinflammation, and multiorgan damage seen in cytokine storm syndromes. The goal of this review is to evaluate how underlying factors contribute to cytokine storm syndromes, as well as the symptomatology, pathology, and long-term implications of these conditions. Although the recognition of cytokine storm syndromes allows for universal treatment with steroids, this therapy shows limitations for symptom resolution and survival. By identifying cytokine storm syndromes as a continuum of disease, this will allow for a thorough evaluation of disease pathogenesis, consideration of targeted therapies, and eventual restoration of the balance in the yin-yang immune response.

Visceral leishmaniasis complicated with hemophagocytic lymphohistiocytosis and resistant to amphotericin B: a case report

INTRODUCTION

Hemophagocytic lymphohistiocytosis characterized by hemophagocytosis leading to uncontrolled inflammation; the most common etiology in secondary cases of hemophagocytic lymphohistiocytosis is viral infections, especially Epstein-Barr virus. Visceral leishmaniasis is a vectorborne protozoal disease caused by Leishmania donovani complex. It is common in tropical and subtropical regions, with 50,000-90,000 new cases annually.

CASE PRESENTATION

A 15-month-old Arab female was admitted to our hospital with 15 days of fever and decreased weight. On clinical examination, she had a markedly enlarged liver and spleen that were palpable 4 cm and 6 cm below the costal margin, respectively. The peripheral blood smear showed hypochromic microcytic anemia, poikilocytosis, reactive lymphocytosis, and mild thrombocytopenia. Bone marrow aspiration did not show malignancy or any other pathological findings. The patient was put on antibiotic therapy without improvement. Repeated bone marrow aspiration showed erythrophagocytosis; intracellular small round organisms looked like the amastigote form of Leishmania (Donovan bodies) with no evidence of malignancies. Her lab values showed ferritin greater than 500 ug/L, pancytopenia, and hypertriglyceridemia. The patient was diagnosed with hemophagocytic lymphohistiocytosis secondary to visceral leishmaniasis.

CONCLUSION

Hemophagocytic lymphohistiocytosis secondary to visceral leishmaniasis is an extensively rare phenomenon in the medical literature that causes challenges in diagnosis and management. Steroids should be used wisely to not cover the symptoms of infections or malignancy, and amphotericin B resistance should be kept in mind in unresponsive Leishmania cases.

Etiological stratification and prognostic assessment of haemophagocytic lymphohistiocytosis by machine learning on onco-mNGS data and clinical data

Introduction

Hemophagocytic lymphohistiocytosis (HLH) is a rare, complicated and life threatening hyperinflammatory syndrome that maybe triggered by various infectious agents, malignancies and rheumatologic disorders. Early diagnosis and identification of the cause is essential to initiate appropriate treatment and improve the quality of life and survival of patients. The recently developed Onco-mNGS technology can be successfully used for simultaneous detection of infections and tumors.

Methods

In the present study, 92 patients with clinically confirmed HLH were etiologically subtyped for infection, tumor and autoimmunity based on CNV and microbial data generated by Onco-mNGS technology, and a predictive model was developed and validated for the differential diagnosis of the underlying disease leading to secondary HLH. Furthermore, the treatment outcomes of patients with HLH triggered by EBV infection and non-EBV infection were evaluated, respectively.

Results

The current study demonstrated that the novel Onco-mNGS can identify the infection and malignancy- related triggers among patients with secondary HLH. A random forest classification model based on CNV profile, infectious pathogen spectrum and blood microbial community was developed to better identify the different HLH subtypes and determine the underlying triggers. The prognosis for treatment of HLH patients is not only associated with CNV, but also with the presence of pathogens and non- pathogens in peripheral blood. Higher CNV burden along with frequent deletions on chromosome 19, higher pathogen burden and lower non-pathogenic microbes were prognosis factors that significantly related with unfavorable treatment outcomes.

Discussion

Our study provided comprehensive knowledge in the triggers and prognostic predictors of patients with secondary HLH, which may help early diagnosis and appropriate targeted therapy, thus improving the survival and prognosis of the patients.

Fatal disseminated Mycobacterium avium infection with bone marrow infiltration and hemophagocytic syndrome

Disseminated non-tuberculous mycobacterial (NTM) infection can affect patients with underlying immunosuppressive conditions. Despite being rare, delay in diagnosis can lead to life-threatening uncontrolled immune response and hemophagocytic syndrome (HPS). We report a case of a 63-year-old female with suspected autoimmune disease, in whom HPS was diagnosed according to HLH-2004 criteria and H-score. Mycobacterium avium (M. avium) was isolated from blood culture, bronchoalveolar lavage (BAL) and bone marrow biopsy. In immunosuppressed patients, early clinical suspicion and prompt microbiological diagnosis of mycobacterial infection together with drug susceptibility tests (DST)-based treatment, as well as HPS, are pivotal to increase the likelihood of treatment success.

CD38high/HLA-DR+CD8+ T lymphocytes display pathogen-specific expansion regardless of hemophagocytic lymphohistiocytosis

The characteristic expansion of T CD38high/HLA-DR+CD8+ lymphocytes observed in hemophagocytic lymphohistiocytosis (HLH) and macrophage activation syndrome (MAS) proved able to distinguish HLH/MAS from sepsis and systemic juvenile idiopathic arthritis. However, the performance of this marker in differentiating HLH/MAS from other pediatric febrile conditions with similar clinical onset and yet entirely different treatments remains unexplored. CD38high/HLA-DR+CD8+ frequencies measured in the peripheral fresh blood of pediatric patients attended for suspicion of HLH/MAS were retrospectively recorded and clinical characteristics were retrieved. CD38high/HLA-DR+CD8+ frequencies in HLH/MAS patients (15 patients; median: 22.0%, IQR: 11.0-49.0%) were compared with those who presented febrile conditions other-than-HLH (28 patients; median: 13.0%, IQR: 3.9-28.7%; p = 0.24). HLH and non-HLH patients were subsequently regrouped based on the presence of an identified infection (22 patients; median: 27.0%, IQR: 15.2-72.1%) and compared with those without infections (21 patients; median: 7.6%, IQR: 3.7-24.3%; p = 0.0035). CD38high/HLA-DR+CD8+ percentages were significantly higher only in the infection group compared with the noninfection one, with a patent pathogen-specific expansion in Epstein-Barr virus primoinfection and visceral leishmaniasis regardless of the presence of HLH. CD38high/HLA-DR+CD8+ frequencies do not appear as an HLH-specific marker as they naturally expand in other clinical situations that are common in childhood and may mimic HLH initial presentation.

Management of chimeric antigen receptor T (CAR-T) cell-associated toxicities

The use of chimeric antigen receptor T (CAR-T) cells is a significant therapeutic improvement increasing the prognosis for patients with a variety of hematological malignancies. However, this therapy has also sometimes life-threatening, complications. Therefore, knowledge of the treatment and management of these complications, especially in treatment centers and intensive care units, respectively, is of outstanding importance. This review provides recommendations for the diagnosis, management, and treatment of CAR-T cell-associated complications such as cytokine release syndrome, immune effector cell associated neurotoxicity syndrome, hematotoxicity, hypogammaglobulinemia, and CAR-T cell-induced pseudo-progression amongst others for physicians treating patients with CAR-T cell-associated complications and intensivists.

Hemophagocytic Lymphohistiocytosis in Association With Neuroblastoma Amplified Sequence (NBAS) Gene Variants: A Report of a Rare Case

Hemophagocytic lymphohistiocytosis (HLH) is a multisystem involvement, hyperinflammatory state with rapid progression and a poor outcome. However, HLH may rarely present with signs and symptoms isolated to the central nervous system (CNS). Thus, we discuss this case, which presented with CNS symptoms and worsened over time with multisystem involvement, an inflammatory storm, and required immunomodulation. Whole exome sequencing performed on genomic DNA extracted from peripheral blood showed a novel finding that the patient was likely compound heterozygous for the following two novel variants of uncertain significance in the neuroblastoma amplified sequence (NBAS) gene (chr2:g.15461289C>T) or c.2251G>A (p.Asp751Asn) on Exon 21 and (chr2:g.15467334A>G) or c.2092T>C (p.Tyr698His) on Exon 19 (genomic coordinates in the GRCh37 format, transcript ID: NM_015909.4). The NBAS gene is needed for cytotoxic degranulation in natural killer (NK) cells and mutation of which dysregulates lytic vesicle transport, thus leading to the hyperinflammatory state. To the best of our knowledge and according to the available literature, this NBAS gene is a rarely documented cause of primary HLH.

Predicting Secondary Hemophagocytic Lymphohistiocytosis in Adult Patients with Scrub Typhus and Its Prognostic Significance

Objective

Secondary hemophagocytic lymphohistiocytosis (sHLH) is an increasingly recognized complication in patients with scrub typhus, potentially contributing to substantial mortality despite appropriate antibiotic treatment. This study aims to determine the prevalence and prognosis of sHLH and identify diagnostic factors in adult patients with scrub typhus in North India.

Methods

This prospective cohort study was conducted at PGIMER, Chandigarh, from August 2021 to November 2023. sHLH was defined as an HScore of 200 or above. The diagnostic performance of biomarkers such as ferritin, fibrinogen, triglycerides, and C-reactive protein was assessed through receiver operating characteristic curve analysis, evaluating area under the curve (AUC), sensitivity, and specificity.

Results

Out of 150 patients (mean age 39 years, 54% female), 28 (18.7%) were diagnosed with sHLH. Those presenting with high-grade fever, seizures, high pulse rate, hepatomegaly, splenomegaly, cytopenia, and significant hepatic dysfunction were more likely to have sHLH. Ferritin demonstrated the highest diagnostic utility (AUC 0.83), compared to fibrinogen (AUC 0.72), triglyceride (AUC 0.67), and C-reactive protein (AUC 0.69). The optimal cutoff for ferritin was 2000 ng/mL, with a sensitivity of 90% and a specificity of 66%. Higher ferritin thresholds (6000 ng/mL and 10000 ng/mL) increased specificity to 88% and 95%, respectively. Patients with sHLH often presented with multi-organ failure, necessitating mechanical ventilation and vasopressor support. In-hospital mortality was significantly higher in sHLH patients than in those without (21.4% vs 6.6%, p = 0.025).

Conclusion

Early detection of sHLH using the HScore and ferritin significantly influences the management of scrub typhus, underscoring the necessity for tailored therapeutic strategies to improve patient outcomes.

How to cite this article

Selvam S, Tuli A, Yuvasai KP, Saini S, Erla SR, Kaur J, et al. Predicting Secondary Hemophagocytic Lymphohistiocytosis in Adult Patients with Scrub Typhus and Its Prognostic Significance. Indian J Crit Care Med 2024;28(9):823-831.

Lymphoma-associated hemophagocytic syndrome: a retrospective, single-center study of 86 patients

To explore the clinical features, treatment, and prognosis of patients with lymphoma-associated hemophagocytic syndrome (LAHS) in a real-world clinical setting. We retrospectively examined LAHS patients diagnosed at our center between January 2016 and August 2023, focusing primarily on their clinical features, therapeutic approaches, overall response rate (ORR), and overall survival (OS). A combination of univariate and multivariate analyses was conducted to identify potential prognostic factors. A total of 86 patients diagnosed with LAHS were included to evaluate clinical characteristics and prognostic factors. Patients with T/NK cell lymphoma had a higher probability of developing hemophagocytic syndrome (HPS) during the clinical process than those with B cell lymphoma. The median survival time was 55 days for all patients, and 47 and 81 days for the T/NK cell LAHS and B cell LAHS cohorts, respectively (P = 0.025). Among the patients evaluated, the ORR was 42.2%. Patients starting with anti-lymphoma treatment had a better, albeit not significant, ORR than those beginning with anti-HPS treatment. In the univariate analysis, T/NK cell LAHS (P = 0.027), HPS onset at relapse (P = 0.036), higher baseline plasma EBV-DNA levels (> 4,000 copies/mL, P = 0.034), and treatments including cytokine adsorption and ruxolitinib (P < 0.001 and P = 0.017, respectively) were potentially associated with worse OS, while corticosteroid therapy benefited OS. In the multivariate analysis, T/NK cell LAHS (adjusted hazard ratio (aHR) = 2.007), cytokine adsorption therapy (aHR = 4.547), and corticosteroid therapy (aHR = 0.118) were independently associated with mortality. T/NK cell lymphoma was the main cause of LAHS and carried a worse prognosis. Whether anti-lymphoma or anti-HPS treatment should start first still requires prospective studies with larger sample sizes. The key point in controlling HPS is to block the cytokine storm promptly. Corticosteroid therapy is both effective and accessible and should be used early and in sufficient quantities.

Acute Hemophagocytic Lymphohistiocytosis Due to Tularemia

Hemophagocytic lymphohistiocytosis (HLH) is a rare, life-threatening disorder marked by excessive immune system activation. Diagnosing HLH is particularly difficult due to its diverse etiology and similar clinical presentation. Patients with HLH often require intensive critical care. The condition is divided into HLH syndrome (genetic defects) and HLH disease, and both can be triggered by factors such as infections, autoimmune diseases, or malignancies. We present here the first documented case of acute HLH secondary to tularemia with septic shock in a 62-year-old female. Initially suspected due to malignancy-induced acute HLH, she was treated with etoposide and dexamethasone and was immediately transitioned to antimicrobials once she was confirmed positive for Francisella tularemia on blood cultures at the state microbiology laboratory. She had a prolonged clinical course of 31 days, followed by an excellent recovery after treatment with antimicrobials. This case highlights the importance of recognizing tularemia as a potential cause of HLH. Identifying and addressing the causative agent promptly is crucial for effective management and treatment of HLH.

Fatal hemophagocytic lymphohistiocytosis with intravascular large B-cell lymphoma following coronavirus disease 2019 vaccination in a patient with systemic lupus erythematosus: an intertwined case

Hemophagocytic lymphohistiocytosis (HLH) has been recognized as a rare adverse event following the coronavirus disease 2019 (COVID-19) vaccination. We report a case of neuropsychiatric symptoms and refractory HLH in a woman with systemic lupus erythematosus (SLE) after receiving her COVID-19 vaccine treated with belimumab, later found to have intravascular large B-cell lymphoma (IVLBCL) at autopsy. A 61-year-old woman with SLE was referred to our hospital because of impaired consciousness and fever. One month prior to consulting, she received her second COVID-19 vaccine dose. Afterward, her consciousness level decreased, and she developed a high fever. She tested negative for SARS-CoV-2. Neuropsychiatric SLE was suspected; therefore, glucocorticoid pulse therapy was initiated on day 1 and 8. She had thrombocytopenia, increased serum ferritin levels and hemophagocytosis. The patient was diagnosed with HLH and treated with etoposide, dexamethasone and cyclosporine. Despite treatment, the patient died on day 75; autopsy report findings suggested IVLBCL as the underlying cause of HLH. Differentiating comorbid conditions remains difficult; however, in the case of an atypical clinical presentation, other causes should be considered. Therefore, we speculate that the COVID-19 vaccination and her autoimmune condition may have expedited IVLBCL development.

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.

Hemophagocytic Lymphohistiocytosis in Visceral Leishmaniasis: A Rare yet Treatable Complication

Hemophagocytic lymphohistiocytosis (HLH) is a rare debilitating condition that can be triggered by an infectious cause, often linked to the Epstein-Barr virus (EBV). In this case, we evaluated a patient with pancytopenia. The bone marrow aspiration revealed the presence of amastigotes and active hemophagocytosis, indicating that the HLH was induced by a Leishmania infection. The patient was treated with lyophilized amphotericin B followed by miltefosine, which effectively resolved the infection and HLH. This case report underscores the presentation and findings of Leishmania-induced HLH, as well as the successful treatment approach that led to improved patient outcomes.

The HScore to Diagnose HLH in Scrub Typhus: Overdiagnosis or under Diagnosis and Does It Really Matter?

How to cite this article: Hegde A. The HScore to Diagnose HLH in Scrub Typhus: Overdiagnosis or under Diagnosis and Does It Really Matter? Indian J Crit Care Med 2024;28(9):811-812.