Treatment outcomes and prognostic factors in adult patients with secondary hemophagocytic lymphohistiocytosis not associated with malignancy

Clinicopathological Prognostic Model for Survival in Adult Patients With Secondary Hemophagocytic Lymphohistiocytosis

BACKGROUND

Data on bone marrow (BM) findings in secondary hemophagocytic lymphohistiocytosis (sHLH) and their association with overall survival (OS) are limited.

OBJECTIVES

This study aimed to develop a prognostic model incorporating BM findings and clinico-laboratory factors affecting OS.

METHODS

We retrospectively evaluated 50 adults with sHLH and developed a clinicopathological prognostic model based on survival-associated factors.

RESULTS

Most patients demonstrated normocellular BM (46.3%) and mild hemophagocytic activity (44.2%). Factors associated with survival in multivariable analyses (MVA) were age above 70 years (hazard ratio [HR] 3.89, p = 0.016), infection-related (HR 4.62, p = 0.006), hemoglobin < 7 g/dL (HR 5.21, p < 0.001), and hypocellular marrow (HR 3.07, p = 0.04). A clinicopathological HLH risk model assigned 1 point to each MVA-identified survival factor, categorizing patients into low- (score 0-1), intermediate- (score 2-3), and high-risk (score 4) groups. The 6-month OS from bootstrapping internal validation among the low-, intermediate-, and high-risk groups were 84.2%, 55.6% (p < 0.001) and 7.7% (p < 0.001), respectively. The area under the receiver operating characteristic curve (AuROC) was 0.87.

CONCLUSIONS

This model stratified sHLH patients into three risk groups with distinct survival outcomes, potentially guiding future therapy.

Clinical characteristics and prognostic factors in patients with fever of unknown origin who developed secondary haemophagocytic lymphohistiocytosis

BACKGROUND

Patients with fever of unknown origin (FUO) can sometimes be accompanied by haemophagocytic lymphohistiocytosis (HLH), a life-threatening disease. The prognostic model and specific markers for the early prognosis and the optimized treatment regimen are of considerable research interest.

RESULTS

A total of 135 FUO/HLH patients were enrolled and classified according to the 60-day outcomes following diagnosis. 79 patients (including 5 patients lost in follow-up) enrolled from 2007 to 2015 served as the derivation cohort, and 56 patients from 2016 to 2023 served as the validation cohort. In the derivation cohort, 27 patients (27/74, 36.5%) survived within 60 days and multivariate analyses showed that age > 67 years (P = 0.003), baseline PLT < 42 × 10^9/L (P = 0.012) and LDH > 1505 U/L (P = 0.002) were associated with a higher mortality rate in HLH patients. The external validation proved the reliability of the prediction model. In derivation cohort, the median alteration of PLT (△PLT) were + 78 × 10^9/L and - 17 × 10^9/L in the survival and non-survival groups, respectively (P < 0.001). The median △LDH was - 197.5U/L in the survival group, while in the non-survival group was + 119U/L (P < 0.001).

CONCLUSIONS

Age, baseline LDH and PLT levels may predict early mortality in secondary HLH patients and identify patients in critical conditions. △LDH and △PLT levels were of high value to monitor the efficacy of therapeutic regimen and the disease progression in HLH patients.

Fungal-Induced Hemophagocytic Lymphohistiocytosis: A Literature Review in Non-HIV Populations

We performed a thorough search of the literature published through December 2024 with no date exclusions on invasive fungal infection (IFI)-induced hemophagocytic lymphohistiocytosis (HLH) in non-human immunodeficiency virus (HIV) patients. The frequency of IFI-induced HLH reported across 16 articles was 9%. Of the 116 identified cases with available clinical information, 53% occurred in immunocompromised patients. IFIs were usually disseminated (76%), with Histoplasma capsulatum being the most common pathogen (51%). IFI and HLH were diagnosed simultaneously in most cases (78%). The 30-day survival rate was 64%. Reported cases had significant heterogeneity in patient characteristics, management strategies, and outcomes.

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.

Hemophagocytic Lymphohistiocytosis Due to Ehrlichiosis: A Case Series

Background

Hemophagocytic lymphohistiocytosis (HLH) is an immunologic syndrome characterized by excessive inflammation and tissue injury due to uncontrolled activation of the phagocytic system. The underlying mechanism is a lack of downregulation of activated macrophages and lymphocytes by natural killer and T cells. Unfortunately, the diagnosis is often delayed or missed due to the rarity of the disease, decreased awareness, and clinical picture variability. Ehrlichiosis is becoming a more prevalent tick-borne illness in endemic regions and a relatively uncommon but increasingly considered cause of HLH.

Case Presentation

We describe the cases of 2 patients diagnosed with secondary HLH as per the 2004 HLH criteria, with the trigger secondary to ehrlichiosis. Our first patient presented with a febrile illness and a remarkably elevated blood ferritin concentration. He ended up meeting HLH criteria despite having a negative bone marrow biopsy. Patient 1 had significant clinical improvement in vitals and had a down-trending ferritin with steroids, doxycycline, and intravenous immunoglobulin. The second patient presented with severe systemic involvement and hemodynamic instability. She was found to have HLH with a positive bone marrow biopsy and a positive Ehrlichia PCR. Patient 2 had significant improvement in her hemodynamic instability with the use of anakinra and doxycycline.

Conclusion

Raising awareness about HLH is imperative for early diagnosis and trigger-directed treatment, which can help in preventing the disease's severe complications. There are an increased number of reports of Ehrlichiosis progressing to HLH. Early identification and treatment with doxycycline, with the use of immunomodulatory treatment in severe cases, has shown favorable outcomes.

Prevalence, trends, and outcomes of hematological malignancies in patients with hemophagocytic lymphohistiocytosis

BACKGROUNDS

Hemophagocytic lymphohistiocytosis (HLH) is an acute, rapidly progressive systemic inflammatory disorder that often occurs secondary to hematological malignancies among other conditions in adults. Although the annual incidence of HLH is increasing, detailed epidemiological knowledge of HLH is still limited, especially in patients with hematological malignancies.

OBJECTIVES

To analyze the impact of hematological malignancies on the epidemiology and outcomes of HLH.

STUDY DESIGN

Data from the National Readmission Database (NRD) from 2011 to 2020 were analyzed to explore the epidemiological trends and in-hospital outcomes of HLH patients, particularly those with hematological malignancies.

RESULTS

Our analysis included 7579 HLH hospitalizations, with hematological malignancies implicated in 24.01% of cases. Our findings reveal a steady increase in HLH diagnoses from 145 cases in 2011 to 1848 in 2020, with the proportion linked to hematological malignancies remaining consistent. Patients with hematological malignancies-associated HLH exhibited higher rates of in-hospital mortality (31.6%) than those without (14.4%), and a higher 30-day readmission rate, underscoring a critical need for early detection and treatment revision.

CONCLUSIONS

Despite the increasing awareness and diagnosis of HLH, the prognosis of patients with HLH associated with hematological malignancies remains poor, highlighting the urgent need for improved management strategies and therapeutic interventions.

[Analysis of CMV and EBV infection in healthy populations in China before and after the COVID-19 pandemic]

Objective: This study aimed to assess the infection status of cytomegalovirus (CMV) and Epstein-Barr virus (EBV) in healthy populations in China over the past decade and analyze the differences in CMV and EBV infection and related risk factors in healthy populations before and after the lifting of coronavirus disease 2019 (COVID-19) pandemic control measures. Methods: This study retrospectively analyzes the CMV and EBV infection status of 8 827 healthy donors who underwent prehematopoietic stem cell transplantation screening at Peking University People's Hospital from January 2014 to December 2023. Logistic regression analysis was conducted to determine the risk factors for CMV and EBV infection. Results: The CMV and EBV IgG positivity rates were 94.52% and 95.40% among the healthy donors, respectively, with no significant differences before and after the lifting of pandemic control measures (all P value>0.05). However, IgG antibody titers increased [CMV: (100.44±36.50) U/ml vs (109.98±36.31) U/ml, P<0.001; EBV: (281.57±226.79) U/ml vs (361.08±268.58) U/ml, P<0.001] after lifting the COVID-19 restrictions. However, the CMV IgM positivity rate remained unchanged. The EBV IgM positivity rate significantly increased after lifting measures (2.77% vs 6.29%, P<0.001), reaching 8.10% within 3 months. Further analysis of the factors affecting EBV IgM positivity revealed that gender (OR=1.479, 95% CI 1.169-1.872, P=0.001), age[compared with the group younger than 18 years, the 18-50-year age group (OR=0.584, 95% CI 0.421-0.820, P=0.002), the >50-year age group (OR=0.389, 95% CI 0.248-0.610, P<0.001) ], and the lifting of COVID-19 restrictions (OR=2.360, 95% CI 1.287-3.047, P<0.001) were independent factors influencing EBV IgM positivity in the general population. The EBV IgM positivity rate in individuals under 18 years old was not affected by gender or the lifting of COVID-19 restrictions when stratified by age group. Both genders (OR=1.499, 95% CI 1.138 - 1.975, P=0.004) and the lifting of COVID-19 restrictions (OR=2.608, 95% CI 1.940-3.507, P<0.001) were independent factors affecting EBV IgM positivity in the 18-50-year age group. The lifting of COVID-19 restrictions (OR=2.222, 95% CI 1.101-4.484, P=0.026) was the sole independent factor affecting EBV IgM positivity in individuals over 50 years old. Conclusions: Previous infection rates of CMV and EBV are high in healthy populations in China, which increase with age. COVID-19 infection may increase EBV reactivation rates in healthy individuals, with a more pronounced effect on those aged >18 years.

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.

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.

A Case Report of Hemophagocytic Lymphohistiocytosis Masquerading as Sepsis

Profound inflammation due to cytokine storm is often the underlying cause of death in patients with hemophagocytic lymphohistiocytosis (HLH). Sepsis, while a precipitant, is also the great masquerader that may hide early signs of HLH. Prompt recognition is important to prevent rapid clinical decline and death. A patient presented with two weeks of unremitting fever of 103°F, dysuria, bilateral flank pain, and confusion. Obstructive uropathy and pyelonephritis were treated with a Foley catheter and antibiotics. There were abnormal developments during his hospitalization including a deep vein thrombus despite prophylactic anticoagulation. Antibiotics and Foley management did not improve fevers or renal injury so he eventually required continuous renal replacement therapy and blood product transfusions. In rapid progression, the patient developed pancytopenia, neutropenia, hyperferritinemia, hypertriglyceridemia, and hypofibrinogenemia suspicious for HLH. A bone marrow biopsy was consistent with progressive T-cell lymphoma, the likely cause of secondary HLH. Antineoplastics, corticosteroids, and opportunistic prophylaxis were pursued. Unfortunately, the cytopenias worsened, and the patient developed shock with hypoxemia and hypotension, followed by cardiac arrest and demise.

A Retrospective Review of Secondary Hemophagocytic Lymphohistiocytosis (HLH) and Dengue-associated HLH from a Teaching Hospital in Singapore

Real-world data on the outcome of Asian patients with secondary hemophagocytic lymphohistiocytosis (HLH), especially on dengue-associated HLH, are limited to small case series. This is a retrospective records review of adult patients with secondary HLH between 2015 and 2020. Thirty-two adult patients were followed up for a median of 6.6 months (range 0.1 - 75 months). 15 had underlying lymphomas, and 12 had viral infections. Hemophagocytosis was seen in 28 of 29 patients with a bone marrow biopsy. 100% and 76.5% of patients with and without an underlying malignancy required HLH-directed therapy and blood product transfusion. 12 of 15 patients with lymphomas were treated with additional chemotherapy. Patients with malignancy-associated HLH had poorer survival than non-malignancy-associated HLH (median overall survival (OS) 1.5 months versus not reached, p-value 0.003). The 1-year survival rates of patients with malignancy-associated HLH, HLH with unknown etiologies, and infection-associated HLH were 0.133 (95% CI: 0.036 - 0.484), 0.400 (95% CI: 0.137 - 1.000) and 0.833 (95% CI: 0.647 - 1.000), respectively. Malignancy significantly increased the risk of death compared to infection-associated HLH (HR 9.37, p-value 0.003). Eight patients were diagnosed with dengue-associated HLH with a median HSCORE of 240 (98-99% probability of HLH). Their mean ferritin was 34,740 ng/mL. Three patients required blood product transfusion, 5 required corticosteroids and/or etoposide, with a median duration of treatment of 31 days. Their overall survival rate was 87.5%. Our study highlights the stark contrast in the survival of secondary HLH patients with and without an underlying malignancy. We also present one of the world's most extensive case series of dengue-associated HLH.

Prognostic factors in patients with secondary hemophagocytic lymphohistioc ytosis in a Chinese cohort

Hemophagocytic lymphohistiocytosis (HLH) is a rare hyperinflammatory syndrome with high mortality mediated by an unbridled and persistent activation of cytotoxic T lymphocytes and natural killer cells. However, the influence factors of early death in adult sHLH patients are still not fully elucidated, which need further investigating. We have conducted an observational study of adult HLH patients between January 2016 and December 2022. All patients are enrolled according to HLH-2004 criteria. Clinical manifestations, laboratory data, treatments, and outcomes have been recorded. Influence factors associated with prognosis are calculated by using logistic regression models. Overall, 220 patients enrolled in this study. The etiologies of HLH were divided into five groups including autoimmune-associated hemophagocytic syndrome (AAHS) (n = 90, 40.9%), malignancies (n = 73, 33.2%), EBV-HLH (n = 18, 8.2%), infection excluded EBV (n = 24, 10.9%), and other triggers (n = 15, 6.8%). Among them, EBV-HLH had the highest mortality (77.8%), and AAHS had the lowest mortality (14.4%). Multivariate analysis indicated that age (≥ 38 years old), cytopenia ≥ 2 lines, platelets (≤ 50 × 109/L), aspartate aminotransferase (≥ 135U/L), prothrombin time (≥ 14.9 s) and activated partial thromboplastin time (≥ 38.5s), EBV, and fungal infection are independent risk factors for poor prognosis of HLH. Adult HLH patients with elder age, cytopenia ≥ 2 lines, levels of decreased platelets, increased AST, prolonged PT and APTT, EBV, and fungal infection tend to have a poor prognosis.

A convenient and practical index for predicting the induction response in adult patients with hemophagocytic lymphohistiocytosis: ferritin/platelet ratio

Hemophagocytic lymphohistiocytosis (HLH) is a hyperinflammatory syndrome with high mortality rate. The response to induction therapy is an important factor affecting survival. The purpose is to investigate laboratory predictors for induction response in adult patients with HLH, which are convenient, practical, and timeliness. Clinical data from January 2017 to December 2020 was retrospectively analyzed, and 269 patients were included. Patients were divided into remission and non-remission groups according to their induction response, 177 in the remission group, and 92 in the non-remission group. We reviewed general characteristics and analyzed the predictive value of serum ferritin, triglycerides, alanine aminotransferase (ALT), and blood cells before and 1-4 weeks after induction therapy for induction response by univariate analysis, ROC curves, etc. There was a correlation between serum ferritin, ALT, leukocytes, neutrophils, hemoglobin, platelets, and induction response (P < 0.05). Serum ferritin and platelets 1-4 weeks after induction therapy, respectively, might be a good predictor for induction response in adults with HLH, with AUC values close to or greater than 0.7. We established a new clinical model of the ferritin/platelet ratio. The results showed that the ferritin/platelet ratio at 1-4 weeks after induction therapy might be a practical index for predicting induction response, which significantly improved the area under the ROC curve (AUC > 0.75). Patients with a ferritin/platelet ratio > 16.08 at 2 weeks after induction therapy may have a relatively poor induction response. Ferritin/platelet ratio after induction therapy can be a good predictor for induction response in adult patients with HLH.

Hemophagocytic Lymphohistiocytosis (HLH) in Patients with Tick-Borne Illness: A Scoping Review of 98 Cases

Hemophagocytic lymphohistiocytosis (HLH) secondary to tick-borne infections is a rare but potentially life-threatening syndrome. We performed a scoping review according to PRISMA guidelines to systematically analyze the existing literature on the topic. A total of 98 patients were included, with a mean age of 43.7 years, of which 64% were men. Most cases, 31%, were reported from the USA. Immunosuppression was present in 21.4%, with the most common cause being previous solid organ transplantation. Constitutional symptoms were the most common, observed in 83.7% of the patients, while fever was reported in 70.4% of cases. Sepsis was present in 27.6%. The most common laboratory abnormalities in this cohort were thrombocytopenia in 81.6% of patients, while anemia, leukopenia, and leukocytosis were observed in 75.5%, 55.1%, and 10.2%, respectively. Liver enzyme elevation was noted in 63.3% of cases. The H-score was analyzed in 64 patients, with the mean value being 209, and bone marrow analysis was performed in 61.2% of patients. Ehrlichia spp. was the main isolated agent associated with HLH in 45.9%, followed by Rickettsia spp. in 14.3% and Anaplasma phagocytophilum in 12.2%. Notably, no patient with Powassan virus infection or Lyme borreliosis developed HLH. The most common complications were acute kidney injury (AKI) in 35.7% of patients, shock with multiple organ dysfunction in 22.5%, encephalopathy/seizure in 20.4%, respiratory failure in 16.3%, and cardiac complications in 7.1% of patients. Treatment included antibiotic therapy alone in 43.9%, while 5.1% of patients were treated with immunosuppressants alone. Treatment with both antibiotics and immunosuppressants was used in 51% of patients. Appropriate empiric antibiotics were used in 62.2%. In 43.9% of cases of HLH due to tick-borne disease, patients received only antimicrobial therapy, and 88.4% of those recovered completely without the need for immunosuppressive therapy. The mortality rate in our review was 16.3%, and patients who received inappropriate or delayed empiric therapy had a worse outcome. Hence, we suggest empiric antibiotic treatment in patients who are suspected of having HLH due to tick-borne disease or in whom diagnostic uncertainty persists due to diagnostic delay in order to minimize mortality.

Liver Dysfunction in Adult Hemophagocytic Lymphohistiocytosis: A Narrative Review

Hemophagocytic lymphohistiocytosis (HLH) is a rare, life-threatening condition that has been increasingly recognized in adults and is characterized by a hyperinflammatory state due to immune dysregulation. Its nonspecific presentation, the lack of clinician familiarity given its rarity, and shared clinical features with sepsis and other syndromes can lead to a delay in diagnosis and a poor prognosis. Significant liver function abnormalities as the initial manifestation of HLH are uncommon and can range from mild elevation of aminotransferases to fulminant hepatic failure with high mortality rates. The authors encountered a case of adult HLH mimicking acute viral hepatitis in which a markedly elevated ferritin level led to a prompt diagnosis, early initiation of treatment, and a successful outcome. Clinicians, including gastroenterologists and hepatologists, are often called upon to evaluate patients with abnormal liver tests and may lack experience in the early diagnosis and management of liver dysfunction in the context of HLH. Thus, we expand our reporting to a narrative review of literature which explores the pathogenesis of HLH, challenges associated with its diagnosis, previous reports of liver disease associated with the syndrome, recommended treatments for the familial and adult variations including the role of liver transplantation, and the outcomes of these treatments.

Prognostic Factors of Adult Hemophagocytic Lymphohistiocytosis and Clinical Utility of HLH-2004 Diagnostic Criteria and HScore: A Real-World Multicenter Study from Thailand

INTRODUCTION

Adult hemophagocytic lymphohistiocytosis (HLH) is a rare disease with a dismal prognosis. Early diagnosis and prompt management are necessary for improved outcomes.

METHODS

This multicenter retrospective study investigated the etiologies, survival, and prognostic factors of HLH, including the utility of HLH-2004 criteria and HScore in real-life clinical practice.

RESULTS

A total of 147 HLH patients were identified by using a combination of hemophagocytosis identification in bone marrow and the HLH-related international classification disease-10. A total of 116 (78.9%) patients fulfilled the HLH diagnosis by HScore, while 91 (61.9%) patients fulfilled 5 of 8 HLH-2004 criteria. In Thailand, the clinical application of HLH-2004 criteria needed to be reduced from 8 to 6 due to a lack of sCD25 and natural killer cell activity tests. Using the adapted HLH-2004 with a cutoff value of 4 resulted in 132 (89.9%) cases meeting the diagnostic criteria. Among these 132 confirmed HLH patients by using adapted HLH-2004, HLH was triggered by infection (29.5%), autoimmune disease (12.9%), malignancy (40.9%), and unknown cause (16.7%). Median overall survival of HLH patients was extremely short (67 days). Ferritin >6,000 μg/L, HLH from infection, malignancy, and unknown etiology were demonstrated as independent prognostic factors for inferior survival (hazard ratio [HR] 2.47; 95% confidence interval [CI] 1.39-4.37, HR 4.69; 95% CI 1.38-15.92, HR 6.09; 95% CI 1.84-20.14, and HR 6.02; 95% CI 1.64-22.05, respectively).

CONCLUSION

Ferritin is a helpful biomarker for HLH diagnosis and prognostic prediction. Autoimmune disease-triggered HLH has favorable outcomes. Future prospective study is required to verify the use of the adapted HLH-2004 criteria.

Inpatient recognition and management of HLH

Hemophagocytic lymphohistiocytosis (HLH) is one of the life-threatening emergencies that a hematologist may be called upon to diagnose and manage. It is a hyperinflammatory process that develops in patients with genetic abnormalities, hematologic malignancies, chronic inflammatory states, or infections. The main clinical challenges are recognizing HLH, determining whether the immune response is aberrant or appropriate, and deciding upon therapy. Patients may present with fever, central nervous system symptoms, cytopenias, or elevated liver enzymes. Recognizing HLH is challenging because its features overlap with numerous systemic disorders, thus requiring a high level of suspicion and timely investigations to confirm the diagnosis and detect the underlying trigger. Once HLH is diagnosed, careful consideration of immunosuppressive therapy's potential benefit versus harm is necessary. Such therapy can sometimes be tailored to the underlying trigger. In the acute setting, the competing pressures of completing a thorough diagnostic process (including evaluation for the presence of lymphoma and infection) and the need for expedited treatment must be balanced. During the management of an HLH patient, continuous vigilance for the presence of as-yet unrecognized disease triggers, monitoring response, and identifying emerging complications is critical. This review will discuss the recognition and management of HLH in the inpatient setting.

Improved hemophagocytic lymphohistiocytosis index predicts prognosis of adult Epstein-Barr virus-associated HLH patients

BACKGROUND

Epstein-Barr virus (EBV)-associated hemophagocytic lymphohistiocytosis (EBV-HLH) is a common subtype of HLH with heterogeneous clinical presentations from self-limited to death, of which adults are worse than children.

OBJECTIVE

To establish predictors of mortality risk in adult EBV-HLH patients for timely and appropriate treatment.

METHODS

Patients with confirmed EBV-HLH admitted to Beijing Friendship Hospital from January 2015 to December 2019 were enrolled and statistical analysis of their laboratory test results was performed.

RESULTS

Among 246 adult patients with EBV-HLH, the deceased were older (p < 0.05), with fewer blood cells (p < 0.05), poorer renal function (p < 0.01), higher levels of procalcitonin (PCT) (p < 0.01), as well as soluble interleukin-2 receptor (sCD25) (p < 0.01). The overall median survival time of patients was 135 days, 87 days for patients without transplantation and 294 days with transplantation (p < 0.001). A combined index of sCD25, PCT, and estimated glomerular filtration rate (eGFR) was obtained to predict prognosis, named the Improved HLH index (IH index), and patients were divided into three groups meeting IH- (i.e. sCD25 ≤ 18,000 pg/mL, PCT ≤ 1.8 ng/mL, eGFR ≥ 90 mL/min/1.73m²), IH1+ (i.e. only sCD25 > 18,000 pg/mL or only eGFR < 90 mL/min/1.73m²), and IH2+ (i.e. the rest), respectively. In patients with the HScore ≥ 169 or meeting HLH-04, those meeting IH2+ had significantly worse prognoses than those who met IH1+ or IH- (p < 0.001). In the group meeting IH + or IH2+, patients who received allo-HSCT had better prognoses than those who did not (p < 0.05), but there was still a significant difference in prognosis among the three groups in transplanted patients (p < 0.001).

CONCLUSION

The IH index can early identify adult patients with a poor prognosis of EBV-HLH, initiating timely and appropriate treatment.KEY MESSAGESA combined index of sCD25, PCT, and eGFR was obtained to predict prognosis, named the Improved Hemophagocytic Lymphohistiocytosis index (IH index).IH index can early identify adult patients with a poor prognosis of EBV-HLH, initiating timely and appropriate treatment.

Clinical characteristics and prognostic factors of 75 cases with acquired hemophagocytic syndrome

OBJECTIVES

The study's aim was to enhance awareness of acquired hemophagocytic syndrome (HPS) in adults by analyzing clinical features, and investigating the relationship between factors such as the Systemic Inflammation Index (SII) and the prognosis of HPS.

METHODS

Clinical characteristics, survival data, and prognostic factors of 75 HPS patients admitted to our hospital between January 2012 and October 2022 were analyzed.

RESULTS

In the high SII group, red blood cells, white blood cells, platelets, neutrophils, fibrinogen, and CD4 + cell activity were higher, and survival time was longer compared to the low SII group. Conversely, total bilirubin and direct bilirubin were higher in the low SII group (P ≤ 0.05). After applying the log-Rank or Breslow tests, HPS patients in the high SII group and those following the HLH-2004 protocol experienced a notably longer survival time. (χ2 = 4.291, P < 0.05; χ2 = 5.210, P < 0.05). Patients with poor prognosis showed higher age of onset, elevated levels of total, direct, and indirect bilirubin, and a greater rate of EBV infection, but reduced levels of red blood cells, platelets, hemoglobin, albumin, globulin, and HLH-2004 protocol usage rate(P < 0.05). Multivariate analysis and ROC curve results indicate that special attention is needed for patients with platelets < 42.5 × 109/L, albumin < 27.7 g/L, fibrinogen < 1.085 g/L, those not following the HLH-2004 protocol, and those who are EBV (+).

DISCUSSION AND CONCLUSION

Early diagnosis and following the HLH-2004 protocol are essential for patients with HPS clinical manifestations to improve prognosis. Additional research is necessary to examine the link between SII and HPS patients' prognosis.

Predictive model for early death risk in pediatric hemophagocytic lymphohistiocytosis patients based on machine learning

Background

Hemophagocytic Lymphohistiocytosis (HLH) is a rare and life-threatening disease in children, with a high early mortality rate. This study aimed to construct machine learning model to predict the risk of early death using clinical indicators at the time of HLH diagnosis.

Methods

This observational cohort study was conducted at the National Clinical Research Center for Child Health and Disease. Data was collected from pediatric HLH patients diagnosed by the HLH-2004 protocol between January 2006 and December 2022. Six machine learning models were constructed using the Least Absolute Shrinkage and Selection Operator (LASSO) to select key clinical indicators for model construction.

Results

The study included 587 pediatric HLH patients, and the early mortality rate was 28.45 %. The logistic and XGBoost model with the best performance after feature screening were selected to predict early death of HLH patients. The logistic model had an AUC of 0.915 and an accuracy of 0.863, while the XGBoost model had an AUC of 0.889 and an accuracy of 0.829. The risk factors most associated with early death were the absence of immunochemotherapy, decreased TC levels, increased BUN and total bilirubin, and prolonged TT. We developed an online calculator tool for predicting the probability of early death in children with HLH.

Conclusions

We developed the first web-based early mortality prediction tool for pediatric HLH to assist clinicians in risk stratification at diagnosis and in developing personalized treatment protocols. This study is registered on the China Clinical Trials Registry platform (ChiCTR2200061315).

A case of hemophagocytic syndrome secondary to B-cell lymphoma

In this report we highlight a case of HPS secondary to B-cell lymphoma, aiming to facilitate the early recognition and treatment of HPS in its classic presentation by clinicians.

Sintilimab treatment for chronic active Epstein-Barr virus infection and Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis in children

BACKGROUND

Chronic active Epstein-Barr virus infection (CAEBV) and Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis (EBV-HLH) are rare but life-threatening progressive diseases triggered by EBV infection. Glucocorticoid/immunosuppressants treatment is temporarily effective; however, most patients relapse and/or progress. Hematopoietic stem cell transplantation (HSCT) is a potentially curative therapy; however, there are risks of transplantation-associated complications. Currently there is no standard treatment for CAEBV and EBV-HLH. Programmed death protein 1 (PD-1) inhibitors have achieved a high response in many EBV-related diseases. Sintilimab (a recombinant human IgG4 monoclonal antibody against PD-1) disrupts the interaction between PD-1 and its ligand, leading to T cell reinvigoration.

METHODS

A retrospective analysis was performed on three children with CAEBV or EBV-HLH in the Children's Hospital of Soochow University between 12 December 2020 and 28 November 2022. The efficacy of sintilimab was evaluated.

RESULTS

Three patients, including two males and one female, were analyzed. Among them, two children were diagnosed with CAEBV with intermittent fever for more than four years, and one child was diagnosed with EBV-HLH. After sintilimab treatment and a mean follow-up of 17.1 months (range 10.0-23.3 months), patients 1 and 3 achieved a complete clinical response and patient 2 achieved a partial clinical response. All three children showed a > 50% decrease in EBV-DNA load in both blood and plasma. EBV-DNA copies in sorted T, B, and NK cells were also markedly decreased after sintilimab treatment.

CONCLUSION

Our data supported the efficacy of PD-1 targeted therapy in certain patients with CAEBV and EBV-HLH, and suggested that sintilimab could provide a cure for these diseases, without HSCT. More prospective studies and longer follow-up are needed to confirm these conclusions.

Risk factors and prognosis of early death in secondary hemophagocytic lymphohistiocytosis

The aim of our study was to summarize the clinical characteristics of early death patients with newly diagnosed secondary hemophagocytic lymphohistiocytosis (sHLH), analyze the risk factors of early death, and analyze the survival of patients. The clinical characteristics of 324 newly diagnosed sHLH patients admitted to the First Affiliated Hospital of Zhejiang University Medical College and Zhejiang Provincial Cancer Hospital from January 2014 to February 2021 were analyzed retrospectively. Analyze the independent risk factors of early death, compare the secondary diseases and treatment methods of patients with early death group and non early death group, and analyze the survival of all patients with sHLH. Among the 324 newly diagnosed patients with sHLH, 134 died early, with an early mortality rate of 41.4%. Comparing the clinical characteristics of patients with early death group and patients with non early death group, logistic regression model was used to conduct multifactor analysis. Age > 60 years, Plt ≤ 20.0 × 109/L, APTT > 36.0 s and LDH > 1000.0 U/L were independent risk factors for early death of newly diagnosed sHLH patients (P < 0.05). Comparing the secondary diseases and treatment methods between early death group and non early death group, the proportion of sHLH patients secondary to lymphoma was higher in early death group than that in non early death group (P < 0.05). The proportion of sHLH patients secondary to connective tissue disease and infection was lower in early death group than that in non early death group (P < 0.05), and the proportion of sHLH patients used hormone combined chemotherapy was lower in early death group than that in non early death group (P < 0.05). The median follow-up time of all patients was 12.0 (1-65) months. The 5-year OS rates of patients with age > 60 years and age ≤ 60 years were 25.8% and 49.6% respectively (P < 0.001); The 5-year OS rates of patients with Plt > 20.0 × 109/L and Plt ≤ 20.0 × 109/L were 52.5% and 25.5% respectively (P < 0.001); The 5-year OS rates of patients with APTT > 36.0 s and APTT ≤ 36.0 s were 34.5% and 57.4% respectively (P < 0.001); The 5-year OS rates of patients with LDH > 1000.0 U/L and LDH ≤ 1000.0 U/L were 23.3% and 56.3% respectively (P < 0.001). Age > 60 years, Plt ≤ 20.0 × 109/L, APTT > 36.0 s and LDH > 1000.0 U/L are independent risk factors for early death of sHLH patients. The early mortality of lymphoma associated HLH (LA-HLH) patients is high, and early use of hormone combined chemotherapy can reduce the early mortality.

Anakinra versus etoposide-based therapy added to high-dose steroids for the treatment of secondary hemophagocytic lymphohistiocytosis

OBJECTIVE

Hemophagocytic lymphohistiocytosis (HLH) is a rare life-threatening, hyperinflammatory syndrome usually treated with high-dose steroids (HDS), often complemented with adjunct therapies, such as etoposide (HLH-94 protocol). Anakinra has been reported to effectively treat HLH; however, has not been comparatively examined with etoposide-based therapies. We sought to evaluate the effectiveness and durability of these treatment approaches.

METHODS

We performed a retrospective analysis of all adult patients diagnosed with secondary HLH between January 2011 and November 2022 who received anakinra and HDS, the HLH-94 protocol, HDS alone, or supportive care.

RESULTS

Thirty adult patients with secondary HLH were included. Cumulative incidence (CI) of response at 30 days was 83.3%, 60%, and 36.4% for patients treated with anakinra, the HLH-94 protocol, and HDS alone, respectively. CI of relapse at 1 year was 50%, 33.3%, and 0% with the HLH-94 protocol, HDS, and anakinra and HDS, respectively. Overall survival at 1 year was higher with anakinra and HDS compared to the HLH-94 protocol, yet was not statistically significant (77.8% vs. 33.3%; hazard ratio: 0.29; p = .25).

CONCLUSION

Treatment with anakinra and HDS in adults with secondary HLH was associated with higher response rates with longer survival compared with alternative therapies and should be further investigated in this setting.

Secondary hemophagocytic lymphohistiocytosis associated with heat stroke: A case report and review of literature

RATIONALE

Hemophagocytic lymphohistiocytosis (HLH) is a syndrome with potentially fatal consequences that results from an excessive immune response caused by malfunctioning natural killer cells and cytotoxic T lymphocytes. Secondary HLH, which is the predominant type in adults, is associated with various medical conditions, including infections, malignancies, and autoimmune diseases. Secondary HLH associated with heat stroke has not been reported.

PATIENT CONCERNS

A 74-year-old male was admitted to the emergency department after being unconscious in a 42°C hot public bath. The patient was witnessed to be in the water for more than 4 hours. The patient's condition was complicated by rhabdomyolysis and septic shock, which were managed with mechanical ventilation, vasoactive agents, and continuous renal replacement therapy. The patient also showed evidence of diffuse cerebral dysfunction.

DIAGNOSES

While the patient's condition initially improved, the patient developed a fever, anemia, thrombocytopenia, and an acute rise in total bilirubin, which, we suspected, was caused by HLH. Further investigations revealed elevated serum ferritin and soluble interleukin-2 receptor levels.

INTERVENTIONS

The patient received 2 cycles of serial therapeutic plasma exchange to lower the endotoxin burden. To manage HLH, high-dose glucocorticoid therapy was done.

OUTCOMES

Despite the best efforts, the patient did not recover and expired from progressive hepatic failure.

LESSONS

We report a novel case of secondary HLH associated with heat stroke. Diagnosing secondary HLH can be difficult since clinical manifestations of the underlying disease and HLH may present simultaneously. Early diagnosis and prompt initiation of treatment is required to improve the prognosis of the disease.

sCD25 as an independent adverse prognostic factor in adult patients with HLH: results of a multicenter retrospective study

Hemophagocytic lymphohistiocytosis (HLH) is a rare but often fatal hyperinflammatory syndrome caused by an inborn or acquired error of immunity. In adults, the underlying immunodeficiency generally arises alongside severe infections, malignancies, autoimmune diseases, and immunosuppressive treatment. To analyze risk factors and outcome in adults, we conducted a multicenter retrospective study. A total of 62 adult (age ≥18 years) patients met at least one of the following inclusion criteria: (1) ≥5 of 8 HLH-2004 criteria, (2) HScore ≥ 200 plus 4 HLH-2004 criteria, or (3) mutation compatible with an HLH diagnosis. Most patients (65%) were male, and the median age at diagnosis was 53.5 years (range, 19-81 years). All patients were assigned to 4 etiologic subgroups based on their most likely HLH trigger. The survival probability of the 4 etiologic subgroups differed significantly (P = .004, log-rank test), with patients with an underlying malignancy having the worst clinical outcome (1-year survival probability of 21%). The parameters older age, malignant trigger, elevated serum levels of aspartate transferase, creatinine, international normalized ratio, lactate dehydrogenase, sCD25, and a low albumin level and platelet count at treatment initiation were significantly (P < .1) associated with worse overall survival in the univariate Cox regression model. In multivariate analysis, sCD25 remained the only significant prognostic factor (P = .005). Our results suggest that sCD25 could be a useful marker for the prognosis of patients with HLH that might help to stratify therapeutic interventions.

Hemophagocytic Lymphohistiocytosis After Greenlight Laser Prostate Surgery

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening systemic inflammatory disease. Multiple risk factors have been defined for the manifestation of HLH. While infection remains the top risk factor, having multiple surgical procedures has also been suggested as a potential risk factor for HLH. Our patient presented with generalized weakness, weight loss, and fatigue after having a greenlight laser prostatectomy for benign prostate hypertrophy; the patient deteriorated rapidly and was found to fulfill the HLH 2004 and modified criteria. We believe this patient had a rare bone marrow disorder with a rare complicated clinical and laboratory presentation.

Serum ferritin is a good indicator for predicting the efficacy of adult HLH induction therapy

Background: Hemophagocytic lymphohistiocytosis (HLH) is a rare clinical syndrome with a high mortality rate. There is no biomarker to predict the early therapeutic response.Objective: Our study explores the significance of serum ferritin in predicting the response of induction therapy.Methods: We retrospectively analyzed the clinical data of 102 adult patients with HLH admitted to our hospital. These patients received HLH-94 regimen for induction therapy. The patients were divided into remission group and non-remission group according to the response of induction therapy. Results: Ferritin values between 1-4 weeks post induction were predictive of remission (p<.05), which were higher in the non-remission group than in the remission group. Ferritin obtained 2 weeks post-induction had the highest ROC for predicting remission, with a cut-off value of 1188.5 µg/L. And patients with ferritin lower than 1188.5 µg/L had better response of induction therapy.Conclusion: Our study suggests that serum ferritin is a good indicator to predict the efficacy of induction therapy for adult HLH. KEY MESSAGESSerum ferritin is a good indicator for predicting the efficacy of adult HLH induction therapy.Serum ferritin two weeks after treatment may be a better indicator to judge the early curative effect.Serum ferritin after treatment also had a predictive significance for the survival of HLH.

Clinical characteristics and risk factors for 90-day overall survival among 204 adult patients with secondary hemophagocytic lymphohistiocytosis: Experience from a single-center retrospective study

Objectives

To describe the clinical characteristics of secondary hemophagocytic lymphohistiocytosis (HLH) among adult patients, investigate its risk factors for 90-day overall survival (OS) from diagnosis, and establish a new prognostic model applicable to adult patients with secondary HLH.

Methods

We conducted a retrospective cohort study of 204 adult patients with secondary HLH, between January 2010 and December 2020. All patients met at least five HLH-2004 criteria. Clinical features, laboratory results, treatments, and clinical outcomes of the patients were reviewed. Prognostic factors associated with 90-day overall survival from diagnosis were screened using Cox proportional hazard models.

Results

The most common trigger was malignancy (61.3%). Multivariate analysis showed that age, coagulopathy, levels of hemoglobin, aspartate aminotransferase (AST), lactate dehydrogenase (LDH), creatinine, ferritin, and prothrombin time (PT) were independent prognostic factors for 90-day OS from the diagnosis of HLH. Based on the above risk factors, the patients were further divided into two groups: low-risk (≤4 risk factors) and high-risk (>4 risk factors), with overall 90-day survival rates of 82.7 and 28.1%, respectively (P < 0.001).

Conclusion

Patients with older age, coagulopathy, lower hemoglobin, and AST levels, elevated LDH, creatinine and ferritin levels, and prolonged PT tended to have a worse prognosis. Moreover, our prognostic model provides the possibility of forecasting the clinical outcome of adult secondary HLH patients, although a larger sample, multicenter, randomized controlled clinical study is needed to verify the accuracy of the prognostic model.

Practice patterns and outcomes of hemophagocytic lymphohistiocytosis in adults: a 2-decade provincial retrospective review

Hemophagocytic lymphohistiocytosis (HLH) is a heterogeneous, life-threatening clinical syndrome. There are scarce data on the quality of care in HLH or data comparing treatment patterns and outcomes between different triggers. We aimed to examine quality-of-care indicators and outcomes in adults with various HLH triggers. In this multi-centre retrospective cohort study of adult HLH in the province of Alberta, Canada (1999-2019), we examined quality indicators including diagnostic testing, time to diagnosis and treatment and trigger identification. We also compared treatment regimens and outcomes across HLH triggers. Logistic regression was used to identify predictors of etoposide use. Overall survival (OS) was estimated using the Kaplan-Meier method. We identified 97 patients; 66 (68%) were male. Triggers included malignancy (36%), infection (35%), autoimmune disease (21%) and idiopathic/others (8%). Specialized tests such as sCD25 (53%) and natural killer degranulation assay (19%) were under-performed, as were testing for infectious triggers. Etoposide was administered in only 33 (34%). Neutropenia, hyperbilirubinemia and hyperferritinemia, but not age, sex and comorbidities, were significant predictors of etoposide use. At median follow-up of 32 months, median OS was 18.8 months. Worse OS was seen in malignancy-associated and idiopathic HLH (log-rank P < 0.001). Our study showed low rates of specialized testing such as sCD25 and a low rate of etoposide use. Development of a standardized provincial protocol has the potential to improve quality of care in adult HLH.

A Study on Early Death Prognosis Model in Adult Patients with Secondary Hemophagocytic Lymphohistiocytosis

Background

The mortality risks for secondary hemophagocytic lymphohistiocytosis in the induction stage and investigated prognostic factors need to be further discussed.

Objective

The aim of this study is to establish a clinical model for predicting early death in adult patients with secondary hemophagocytic lymphohistiocytosis. Design, Participants, and Main Measures. The baseline characteristics, laboratory examination results, and 8-week survival rate of 139 adult sHLH patients diagnosed from January 2018 to December 2018 were analyzed retrospectively, and a prognostic model was constructed with low-risk (score 0–2), medium-risk (score 3), and high-risk (score ≥ 4) as parameters. Key Results. Univariate analysis confirmed that early death was not related to the type of HLH but significantly related to the patient's response to first-line treatment. The peripheral blood cell count was significantly decreased, C-reactive protein was higher, glutamyl transpeptidase and total bilirubin were higher, albumin was significantly lower, urea nitrogen was higher, hypocalcemia and hyponatremia, deep organ hemorrhage and D-dimer increased, cardiac function damage and HLH central involvement, sCD25 increased, and EB virus infection were predictive factors of early death. In the multivariate model, patients' response to first-line treatment was a good predictor of overall survival, and hypocalcemia and deep organ bleeding were associated with poor survival. The risk factors were scored and graded according to the risk ratio. The 8-week overall survival rates of the low-risk group (82 cases), medium-risk group (36 cases), and high-risk group (21 cases) were 85.4%, 52.8%, and 23.8%, respectively (P < 0.001).

Conclusions

The early death of sHLH patients is closely related to some laboratory examination results. Attention should be paid to identify high-risk patients, choose effective first-line induction therapy, achieve deep remission as soon as possible, prevent deep organ bleeding, correct electrolyte disorders, and improve the early survival rate of sHLH patients.

A Review of Hemophagocytic Lymphohistiocytosis in Patients With HIV

We provide an elaborate review of cases published between January 2005 and April 2021 on hemophagocytic lymphohistiocytosis (HLH) in HIV patients. Seventy articles describing 81 adult patients (age ≥19 years) were included. The median age was 40 years, and 78% were males. Only 65% were known to have HIV before presentation. CD4 count was ≥200 cells/mm3 in 23%, and HIV viral load was <200 copies/mL in 41%. The lack of meticulous reporting of ≥5 of 8 criteria for HLH diagnosis was evident in a third of cases. At least 1 infectious agent-other than HIV-was believed to trigger HLH in 78% of patients. The most common were Epstein-Barr virus (26%), human herpesvirus 8 (21%), and Histoplasma capsulatum (17%). Sixty percent survived. Among those, 93% received treatment for identified secondary trigger(s), while 51% received HLH-directed therapy. There was significant heterogeneity in the treatment regimens used for HLH.

Simple Evaluation of Clinical Situation and Subtypes of Pediatric Hemophagocytic Lymphohistiocytosis by Cytokine Patterns

Background

Hemophagocytic lymphohistiocytosis (HLH) is a rapidly fatal disease caused by immune dysregulation. Early initiation of treatment is imperative for saving lives. However, a laboratory approach that could be used to quickly evaluate the HLH subtype and clinical situation is lacking. Our previous studies indicated that cytokines such as interferon (IFN)-γ and interleukin (IL)-10 were helpful for the early diagnosis of HLH and were associated with disease severity. The purpose of this study is to clarify the different cytokine patterns of various subtypes of pediatric HLH and to investigate the role of cytokines in a simple evaluation of disease feature.

Patients and Methods

We enrolled 256 pediatric patients with newly diagnosed HLH. The clinical features and laboratory findings were collected and compared among different subtypes of HLH. A model integrating cytokines was established to stratify HLH patients into different clinical groups.

Results

Twenty-seven patients were diagnosed with primary HLH (pHLH), 179 with EBV-HLH, and 50 with other causes. The IL-6, IL-10, and IFN-γ levels and the ratios of IL-10 to IFN-γ were different among EBV-HLH, other infection-associated HLH, malignancy-associated HLH, familial HLH, and X-linked lymphoproliferative disease. Patients with the ratio of IL-10 to IFN-γ &gt;1.33 and the concentration of IFN-γ ≤225 pg/ml were considered to have pHLH, with a sensitivity of 73% and a specificity of 84%. A four-quadrant model based on the two cutoff values was established to stratify the patients into different clinical situations. The HLH subtypes, cytokine levels, treatment regimens, treatment response, and outcomes were different among the four quadrants, with the 8-week mortality from 2.9 ± 2.9% to 21.4 ± 5.5% and the 5-year overall survival from 93.9 ± 4.2% to 52.6 ± 7.1%.

Conclusions

Different subtypes of HLH present distinct cytokine patterns. IFN-γ and the ratio of IL-10 to IFN-γ are helpful tools to differentiate HLH subtypes. A four-quadrant model based on these two parameters is a useful tool for a simple evaluation of the HLH situation.

Hemophagocytic Lymphohistiocytosis and Infection: A Literature Review

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

Low total cholesterol predicts early death in children with hemophagocytic lymphohistiocytosis

BACKGROUND

Hemophagocytic lymphohistiocytosis (HLH) is a rapidly progressive and potentially life-threatening disorder. Identifying risk factors and timely adjustment of the given treatment regimens is critical to reducing the early mortality in HLH patients. Hypocholesterolemia has been reported to be associated with poor prognosis in a variety of critical illnesses. However, serum cholesterol is rarely studied in HLH patients, and its prognostic value is unclear.

METHODS

We conducted a retrospective cohort study in National Clinical Research Center for Child Health and Disorders (Chongqing), identifying pediatric HLH patients (including genetically confirmed pHLH and not genetically confirmed pHLH) diagnosed with the HLH-2004 protocol and treated with immunochemotherapy between January 2008 and December 2020. The patients' blood lipid levels at initial diagnosis of HLH, including triglycerides (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein-cholesterol (LDL-C), were reviewed based on electronic medical records. Both Cox and logistic regression models were used to estimate the effects of blood lipid indicators on early death (within 30 days after diagnosis).

RESULTS

A total of 353 patients were enrolled in the study, with a median age at diagnosis of 45 months. The observed 30-day mortality rate was 19.05% (64/336, 17 were lost to follow-up) and Kaplan-Meier-estimated 3-year survival rate was 61.67% (95% CI, 56.27%-67.59%). DNA-targeted sequencing of HLH-related genes was performed in 173 (49.0%, 173/353) patients (not all patients with suspected pHLH underwent genetic testing), and 29 patients were diagnosed with genetically confirmed pHLH. Lipid panel was performed in 349 patients: 91.98% (321/349) had TG ≥ 1.80 mmol/L, 62.75%(219/349) had TG ≥ 3.00 mmol/L, 92.84% (324/349) had HDL-C ≤ 1.04 mmol/L, 58.74% (205/349) had LDL-C ≤ 1.30 mmol/L and 24.64% (86/349) had TC ≤ 3.11 mmol/L. TC ≤ 3.11 mmol/L and BUN ≥ 7.14 mmol/L were the independent risk factors for 30-day mortality [HR(95%CI): 2.85(1.46, 5.57) and 2.90(1.48, 5.68), respectively]. The presence of one of these risk factors increased the 30-day mortality rate by 6-fold [HR = 6.24, 95%CI: (3.18, 12.22)] and the presence of two risk factors by nearly 10-fold [HR = 9.98, 95%CI: (4.23, 23.56)] compared with the patients with no risk factors.

CONCLUSION

Severe derangement of lipoproteins is common in children with HLH, and decreased TC is an independent risk factor for early death. Hypocholesterolemia should be included as a biomarker during the diagnosis and management of HLH patients.

Central nervous system involvement and thrombocytopenia as predictors of mortality in children with hemophagocytic lymphohistiocytosis

INTRODUCTION

Hemophagocytic lymphohistiocytosis (HLH) is a potentially life-threatening condition. This study aimed to evaluate treatment outcomes and identify prognostic-related factors in Thai children with HLH.

MATERIALS AND METHODS

We retrospectively reviewed the medical records of 76 pediatric patients with HLH who were treated at Ramathibodi Hospital between January 2004 and December 2019. Treatment outcomes were defined as early mortality (death within 30 days after diagnosis) and early treatment response (resolution of all clinical features and normalization of at least one HLH-related laboratory parameter within 4 weeks).

RESULTS

The overall mortality rate was 38% (29/76), with an early mortality rate of 45% (13/29). Malignancy-associated HLH had the highest mortality rate (88%), followed by primary HLH (56%). The predictors of early mortality were central nervous system (CNS) involvement [OR 13 (95%CI 2-83), p = 0.007] and platelet counts <44 × 10⁶/mm³ [OR 8 (95%CI 1.3-49), p = 0.024]. The predictors of early treatment response were no CNS involvement [OR 6.6 (95%CI 1.5-28.8), p = 0.011], platelet counts more than 44 × 10⁶/mm³ [OR 8 (95%CI 2.1-30.9), p = 0.003], and total bilirubin levels <1.8 mg/dL [OR 4 (95%CI 1.1-14.8), p = 0.036]. In the mixed-model analysis, platelet counts in non-survivors increased significantly less than those in survivors, with a mean difference in platelet changes between the two groups of 94.6 × 10⁶/mm³ (p = 0.003).

CONCLUSION

The independent predictors of early mortality in children with HLH were CNS involvement and low baseline platelet counts. A slow rate of platelet increases during the first week after diagnosis was also associated with mortality.

Risk factors of early death in pediatric hemophagocytic lymphohistocytosis: Retrospective cohort study

BACKGROUND

Hemophagocytic lymphocytosis (HLH) is a rare life-threatening hyperinflammatory syndrome in which early mortality remains high in patients with HLH.

METHODS

We retrospectively collected the medical records of all pediatric patients diagnosed with HLH at the West China Second Hospital of Sichuan University between January 2014 and December 2020. Collect demographic, laboratory, clinical, genetic profiles, treatment information and perform statistical analysis from records. Risk factors for death 30 days after admission were evaluated using a multivariable logistic regression model.

RESULTS

A total of 110 pediatric HLH patients were enrolled. The median age of patients was 44 months (IQR 23-100.5) and 62 (56.4%) in males. The 30-day mortality rate for admission to this cohort was 34 (30.9%). Multivariate logistic regression analysis showed that heart failure (OR = 13.389, 95% CI, 1.671-107.256, p = 0.015) and hypoproteinemia (OR = 4.841, 95% CI, 1.282-18.288, p = 0.020) were associated with increased early mortality in children with HLH.

CONCLUSIONS

These identified risk factors may help clinicians stratify patients with HLH and develop targeted treatment strategies. More research is needed to explore the best treatment strategies for patients with HLH to reduce early mortality in patients with HLH.

A case of VEXAS syndrome associated with EBV-associated hemophagocytic lymphohistiocytosis

Vacuoles, E1, X-linked, autoimmunity, somatic (VEXAS) syndrome is characterized by a pathogenic mutation in UBA1, which leads to protean complications including autoimmunity and myelodysplasia. A 56-year-old man with steroid-dependent, later steroid-refractory cutaneous polyarteritis nodosa and Sweet syndrome developed recurrent daily fever, macrocytic anemia, thrombocytopenia, acute hypoxic respiratory failure, and anasarca. He was eventually diagnosed with Epstein-Barr virus (EBV) viremia and hemophagocytic lymphohistiocytosis (HLH). He improved clinically with rituximab, ruxolitinib, and increased glucocorticoids before expiring from Pseudomonas sepsis. UBA1 exon 3 mutational analysis in myeloid enriched peripheral blood revealed a c.122T>C (p.Met41Thr) pathogenic variant, consistent with VEXAS syndrome. We describe the first case of EBV-associated HLH in a patient diagnosed with VEXAS syndrome. Early identification of this syndrome will be important in order to offer potential therapies before life-threatening complications arise.

Hemophagocytic Lymphohistiocytosis: Early Treatment Leading to an Excellent Outcome

HLH is a rare and deadly disease increasingly more present in adults, but following treatment protocol may yield favorable results.

Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis in a postpartum patient with preeclampsia: a case report

Hemophagocytic lymphohystiocytosis is an extremely life-threatening immune deregulatory syndrome. It is characterized by pathologic activation of immune cells, leading to excessive cytokine production, multiorgan failure, and potentially, death. A 28-year-old primigravida at 32 weeks and 3 days of gestation presented with newly-diagnosed preeclampsia with severe features, fever, and fetal tachycardia. She was delivered by cesarean delivery. After delivery, she had a fever of unknown origin, with evidence of a hyperinflammatory state. Extensive infectious work-up was significant for positive Epstein-Barr Virus. A bone marrow biopsy demonstrated hemophagocytosis. She was diagnosed with Epstein-Barr-Virus-associated hemophagocytic lymphohystiocytosis and was treated with immunosuppression and chemotherapy. Hemophagocytic lymphohistiocytosis is a rare, life-threatening immune dysregulatory syndrome with both genetic and extragenic triggers that can occur in the postpartum period. Rituximab is an effective add-on therapy to conventional treatment.

Spontaneous Recovery of Hemophagocytic Lymphohistiocytosis Due to Primary Epstein-Barr Virus Infection in an Adult Patient

Patient: Male, 34-year-old

Final Diagnosis: Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis

Symptoms: Fever • rash

Medication: —

Clinical Procedure: —

Specialty: Hematology • Immunology • Infectious Diseases

Hemophagocytic Lymphohistiocytosis

CONTEXT.—

Hemophagocytic lymphohistiocytosis (HLH) is a rare, life-threatening disorder of immune regulation that can eventually result in end-organ damage and death. HLH is characterized by uncontrolled activation of cytotoxic T lymphocytes, natural killer cells, and macrophages that can lead to a cytokine storm. The diagnosis of HLH is often challenging due to the diverse clinical manifestations and the presence of several diagnostic mimics. The prognosis is generally poor, warranting rapid diagnosis and aggressive management.

OBJECTIVE.—

To provide a comprehensive review of the pathogenesis, clinical features, diagnosis, and management of HLH.

DATA SOURCES.—

Peer-reviewed literature.

CONCLUSIONS.—

HLH is a condition where a complete understanding of the pathogenesis, early diagnosis, and proper management has an important role in determining patient outcome. Genetic mutations causing impairment in the function of cytotoxic T lymphocytes and natural killer cells have been identified as the root cause of familial HLH; however, the specific pathogenesis of acquired HLH is unclear. The HLH-2004 protocol used in the diagnosis of HLH was originally developed for the pediatric population. The HLH-2004 protocol still forms the basis of the diagnosis of HLH in adults, although its use in adults has not been formally validated yet. Treatment of HLH is primarily based on the HLH-94 protocol, which involves suppressing the inflammatory response, but the treatment needs to be modified in adults depending on the underlying cause and comorbidities.

Epidemiological investigation of hemophagocytic lymphohistiocytosis in China

Background

Currently, most research on hemophagocytic lymphohistiocytosis (HLH) have focused on etiology and therapy, leaving few epidemiological reports. The published studies of China are mainly regional investigations. We aimed to present the overall epidemiological status of HLH in China, and provide Chinese data for the international HLH epidemiological investigation.

Methods

The data of HLH cases in China in 2019 were collected and statistically analyzed.

Findings

Epstein-Barr virus accounted for 44.01% of the 1445 cases in 31 regions and was the most common cause. Lymphoma-associated HLH patients were more often male (P < 0.05) while rheumatic and immune-associated HLH were more often female (P < 0.001). Primary HLH and Epstein-Barr Virus-associated HLH were predominant in children (P < 0.001) while tumor-associated HLH was predominant in adults. Lymphoma-associated HLH was positively correlated with the age of onset (P < 0.01). The diagnosis rate of 29 areas had a significant correlation with per capita Gross domestic product (P < 0.05).

Conclusion

The different distribution of HLH etiology by age and gender contributes to the diagnosis of HLH by clinicians; The suboptimal diagnosis rate in regions with a high incidence of HLH in China is a result of the effect of the local economic level indicating the importance of improving the regional medical level.

Biomarkers of cytokine storm as red flags for severe and fatal COVID-19 cases: A living systematic review and meta-analysis

OBJECTIVE

To describe the laboratory parameters and biomarkers of the cytokine storm syndrome associated with severe and fatal COVID-19 cases.

METHODS

A search with standardized descriptors and synonyms was performed on November 28th, 2020 of the MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, ClinicalTrials.gov, LILACS, and IBECS to identify studies of interest. Grey literature searches and snowballing techniques were additionally utilized to identify yet-unpublished works and related citations. Two review authors independently screened the retrieved titles and abstracts, selected eligible studies for inclusion, extracted data from the included studies, and then assessed the risk of bias using the Newcastle-Ottawa Scale. Eligible studies were those including laboratory parameters-including serum interleukin-6 levels-from mild, moderate, or severe COVID-19 cases. Laboratory parameters, such as interleukin-6, ferritin, hematology, C-Reactive Protein, procalcitonin, lactate dehydrogenase, aspartate aminotransferase, creatinine, and D-dimer, were extracted from the studies. Meta-analyses were conducted using the laboratory data to estimate mean differences with associated 95% confidence intervals.

DATA SYNTHESIS

The database search yielded 9,620 records; 40 studies (containing a total of 9,542 patients) were included in the final analysis. Twenty-one studies (n = 4,313) assessed laboratory data related to severe COVID-19 cases, eighteen studies (n = 4,681) assessed predictors for fatal COVID-19 cases and one study (n = 548) assessed laboratory biomarkers related to severe and fatal COVID-19 cases. Lymphopenia, thrombocytopenia, and elevated levels of interleukin-6, ferritin, D-dimer, aspartate aminotransferase, C-Reactive-Protein, procalcitonin, creatinine, neutrophils and leucocytes were associated with severe and fatal COVID-19 cases.

CONCLUSIONS

This review points to interleukin-6, ferritin, leukocytes, neutrophils, lymphocytes, platelets, C-Reactive Protein, procalcitonin, lactate dehydrogenase, aspartate aminotransferase, creatinine, and D-dimer as important biomarkers of cytokine storm syndrome. Elevated levels of interleukin-6 and hyperferritinemia should be considered as red flags of systemic inflammation and poor prognosis in COVID-19.

Natural-killer cell cytotoxicity as a diagnostic and prognostic marker for adult patients with secondary hemophagocytic lymphohistiocytosis: a prospective phase II observational study

BACKGROUND

Hemophagocytic lymphohistiocytosis (HLH) can be life-threatening if not detected and treated appropriately. The diagnosis of HLH can be confusing due to other similar febrile diseases that present with cytopenia. Natural-killer cell (NK)-cytotoxicity is an important diagnostic parameter for primary HLH; however, its role in secondary HLH in adults has not been well-elucidated.

METHODS

We prospectively enrolled 123 adult patients with febrile conditions accompanied by cytopenia or marrow hemophagocytosis. A diagnosis of HLH was based on HLH-2004 criteria and treated based on HLH-94 protocol. NK-cytotoxicity was calculated at the time of diagnosis by K562-cell direct lysis using flow-cytometry.

RESULTS

HLH (n = 60) was determined to be caused by Epstein-Barr virus (EBV) (n = 11), infection other than EBV (n = 16), malignancies (n = 19), and unknown (n = 14). Febrile diseases other than HLH (n = 63) were diagnosed as autoimmune disease (n = 22), malignancies (n = 21), infection (n = 12), non-malignant hematological diseases (n = 6), and unknown (n = 2). A lower NK-cytotoxicity level was observed at diagnosis in patients with HLH, compared with other causes of febrile disease (12.1% versus 26.2%, p < 0.001). However, NK-cytotoxicity had a borderline effect on diagnosis of HLH, with an area under receiver operation characteristic curve of 0.689. It also showed no significant role for the prediction of survival outcome. Multivariate analysis revealed that malignant disease and high ferritin level were related with poor survival outcome. In non-malignant disease subgroups, old age, EBV-association, and low NK-cytotoxicity were related with poor survival.

CONCLUSIONS

Febrile disease with cytopenia was associated with decreased NK-cytotoxicity, especially in adults with HLH; however, its diagnostic role for adult HLH is still arguable. The diagnostic criteria for adult HLH should be further discussed.

TRIAL REGISTRATION

Clinical Research Information Service [Internet]; Osong (Chungcheongbuk-do), Korea, Centers for Disease Control and Prevention, Ministry of Health and Welfare (Republic of Korea); https://cris.nih.go.kr/cris/index.jsp; Feb, 16th 2016; KCT0001886 (KC15TISE0936).

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

OBJECTIVES

Hemophagocytic lymphohistiocytosis is a cytokine release syndrome caused by uncontrolled immune activation resulting in multiple organ failure and death. In this systematic review, we aimed to analyze triggers, various treatment modalities, and mortality in critically ill adult hemophagocytic lymphohistiocytosis patients.

DATA SOURCES

MEDLINE database (PubMed) at October 20, 2019.

STUDY SELECTION

Studies and case series of patients greater than or equal to 18 years old, of whom at least one had to be diagnosed with hemophagocytic lymphohistiocytosis and admitted to an ICU.

DATA EXTRACTION

Source data of studies and case series were summarized and analyzed on an individual basis. Multivariable logistic regression analysis was performed adjusting for age, sex, and trigger groups. Each single treatment agent was entered as a dichotomous variable to determine treatments associated with survival, regardless if given alone or in combination.

DATA SYNTHESIS

In total, 661 patients from 65 studies and case series were included. Overall mortality was 57.8%. Infections were the most frequent trigger (49.9%), followed by malignancies (28.0%), autoimmune diseases (12.1%), unknown triggers (9.4%), and drugs (0.6%). Treatment with IV immunoglobulins was associated with improved survival (odds ratio, 0.548; 95% CI, 0.337-0.891; p = 0.015), while treatment with cyclosporine was associated with increased risk of death (odds ratio, 7.571; 95% CI, 3.702-15.483; p < 0.001). Considering different trigger groups separately, same results occurred only for infection-triggered hemophagocytic lymphohistiocytosis. No information was available on disease severity and other confounding factors.

CONCLUSIONS

Mortality of hemophagocytic lymphohistiocytosis in the ICU is high. Most common triggers were infections. Results of survival analyses may be biased by treatment indication and disease severity. Future studies prospectively investigating treatment tailored to critically ill hemophagocytic lymphohistiocytosis patients are highly warranted.

Clinical analysis and a novel risk predictive nomogram for 155 adult patients with hemophagocytic lymphohistiocytosis

Recently, more and more attention has been paid on adult hemophagocytic lymphohistiocytosis (HLH), a disease with complicated symptoms and high mortality. In order to analyze the clinical characteristics and prediction risk factors of mortality, we designed a retrospective study with 1-year follow-up and included 155 patients admitted to Tongji Hospital diagnosed as HLH. One hundred seven patients formed the training cohort for nomogram development, and 48 patients formed the validation cohort to confirm the model's performance. All patients' clinical characteristics, laboratory results, medical records, and prognosis were analyzed. Among all the 107 patients in the training cohort, 46 were male and 61 were female, with the median age of 49.0 (IQR 31.0-63.0). The 1-year mortality rate was 43.9% (47/107) and 45.8% (22/48) in the training and validation cohort, respectively. And further multivariate logistic regression analysis in the training cohort showed that male (odds ratio 5.534, 95% CI 1.507-20.318, p = 0.010), altered mental status (11.876, 1.882-74.947, p = 0.008), serum ferritin ≥ 31,381 μg/L (8.273, 1.855-36.883, p = 0.006), and IL-6 ≥ 18.59 pg/mL (19.446, 1.527-247.642, p = 0.022) were independent risk factor of mortality. A nomogram included the four prediction factors mentioned above was also tabled to help clinicians evaluate the probability of poor outcome. Area under the receiver operating characteristic curve (AUROC) analysis, calibration curves, and decision curve analysis (DCA) certify the accuracy and the clinical usefulness of the nomogram. Our research reveals that male, altered mental status, serum ferritin ≥ 31,381 µg/L, and IL-6 ≥ 18.59 pg/mL are four independent predictors for poor prognosis. Doctors should pay more attention to patients with altered mental status, high serum ferritin, and IL-6 level, who have a higher risk of death.

Current status of the diagnosis and treatment of hemophagocytic lymphohistiocytosis in adults

Hemophagocytic lymphohistiocytosis (HLH) is a syndrome of defective apoptosis, a disruption of the regulatory pathway that terminates immune and inflammatory responses. Fever, cytopenia, splenomegaly, and/or hemophagocytosis are typical findings of this syndrome. HLH can be induced by genetic disorders (familial) or secondary causes. Familial HLH is rare, while secondary causes in adults include infection, autoimmunity, and malignancy. HLH in adults tends to be confused with or misdiagnosed as sepsis, mainly due to similar clinical manifestations and laboratory findings, which make it difficult to diagnose HLH rapidly and adopt immunosuppressive agents and/or chemotherapy adequately. Treatment of pediatric HLH using HLH-2004 or multi-agent chemotherapy can be applied in adult patients, although the dose and type of drug need to be adjusted. It is highly recommended that allogenic hematopoietic stem cell transplantation should be used in patients who become reactivated or are refractory to the initial treatment as soon as possible to improve survival. Future clinical trials are warranted to determine more suitable treatments for adult patients with HLH.

Death of unknown cause? Post-mortem diagnosis of fulminant course of an EBV-associated secondary hemophagocytic lymphohistiocytosis

HLH is a life-threatening disease, which is characterized by a dysregulated immune response with uncontrolled T cell and macrophage activation. The often fulminant course of the disease needs a fast diagnostic work-up to initiate as soon as possible the appropriate therapy. We present herein the case of a 71-year-old patient with rapidly progressive hyperinflammatory syndrome, which post mortem resulted in the diagnosis of EBV-associated HLH. With this case report, we intend to highlight the relevance of the HScore in the diagnosis of HLH, to create a greater awareness for EBV as a trigger of HLH, and to demonstrate the importance of treating EBV-associated HLH as early as possible.