Reevaluating the role of ferritin in the diagnosis of adult secondary hemophagocytic lymphohistiocytosis

Early identification of macrophage activation syndrome secondary to systemic lupus erythematosus with machine learning

OBJECTIVE

The macrophage activation syndrome (MAS) secondary to systemic lupus erythematosus (SLE) is a severe and life-threatening complication. Early diagnosis of MAS is particularly challenging. In this study, machine learning models and diagnostic scoring card were developed to aid in clinical decision-making using clinical characteristics.

METHODS

We retrospectively collected clinical data from 188 patients with either SLE or the MAS secondary to SLE. 13 significant clinical predictor variables were filtered out using the Least Absolute Shrinkage and Selection Operator (LASSO). These variables were subsequently utilized as inputs in five machine learning models. The performance of the models was evaluated using the area under the receiver operating characteristic curve (ROC-AUC), F1 score, and F2 score. To enhance clinical usability, we developed a diagnostic scoring card based on logistic regression (LR) analysis and Chi-Square binning, establishing probability thresholds and stratification for the card. Additionally, this study collected data from four other domestic hospitals for external validation.

RESULTS

Among all the machine learning models, the LR model demonstrates the highest level of performance in internal validation, achieving a ROC-AUC of 0.998, an F1 score of 0.96, and an F2 score of 0.952. The score card we constructed identifies the probability threshold at a score of 49, achieving a ROC-AUC of 0.994 and an F2 score of 0.936. The score results were categorized into five groups based on diagnostic probability: extremely low (below 5%), low (5-25%), normal (25-75%), high (75-95%), and extremely high (above 95%). During external validation, the performance evaluation revealed that the Support Vector Machine (SVM) model outperformed other models with an AUC value of 0.947, and the scorecard model has an AUC of 0.915. Additionally, we have established an online assessment system for early identification of MAS secondary to SLE.

CONCLUSION

Machine learning models can significantly improve the diagnostic accuracy of MAS secondary to SLE, and the diagnostic scorecard model can facilitate personalized probabilistic predictions of disease occurrence in clinical environments.

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.

The 2022 EULAR/ACR Points to Consider at the Early Stages of Diagnosis and Management of Suspected Haemophagocytic Lymphohistiocytosis/Macrophage Activation Syndrome (HLH/MAS)

OBJECTIVE

Haemophagocytic lymphohistiocytosis (HLH) and macrophage activation syndrome (MAS) are life-threatening systemic hyperinflammatory syndromes that can develop in most inflammatory contexts. They can progress rapidly, and early identification and management are critical for preventing organ failure and mortality. This effort aimed to develop evidence-based and consensus-based points to consider to assist clinicians in optimising decision-making in the early stages of diagnosis, treatment and monitoring of HLH/MAS.

METHODS

A multinational, multidisciplinary task force of physician experts, including adult and paediatric rheumatologists, haematologist/oncologists, immunologists, infectious disease specialists, intensivists, allied healthcare professionals and patients/parents, formulated relevant research questions and conducted a systematic literature review (SLR). Delphi methodology, informed by SLR results and questionnaires of experts, was used to generate statements aimed at assisting early decision-making and optimising the initial care of patients with HLH/MAS.

RESULTS

The task force developed 6 overarching statements and 24 specific points to consider relevant to early recognition of HLH/MAS, diagnostic approaches, initial management and monitoring of HLH/MAS. Major themes included the simultaneous need for prompt syndrome recognition, systematic evaluation of underlying contributors, early intervention targeting both hyperinflammation and likely contributors, careful monitoring for progression/complications and expert multidisciplinary assistance.

CONCLUSION

These 2022 EULAR/American College of Rheumatology points to consider provide up-to-date guidance, based on the best available published data and expert opinion. They are meant to help guide the initial evaluation, management and monitoring of patients with HLH/MAS in order to halt disease progression and prevent life-threatening immunopathology.

The 2022 EULAR/ACR points to consider at the early stages of diagnosis and management of suspected haemophagocytic lymphohistiocytosis/macrophage activation syndrome (HLH/MAS)

OBJECTIVE

Haemophagocytic lymphohistiocytosis (HLH) and macrophage activation syndrome (MAS) are life-threatening systemic hyperinflammatory syndromes that can develop in most inflammatory contexts. They can progress rapidly, and early identification and management are critical for preventing organ failure and mortality. This effort aimed to develop evidence-based and consensus-based points to consider to assist clinicians in optimising decision-making in the early stages of diagnosis, treatment and monitoring of HLH/MAS.

METHODS

A multinational, multidisciplinary task force of physician experts, including adult and paediatric rheumatologists, haematologist/oncologists, immunologists, infectious disease specialists, intensivists, allied healthcare professionals and patients/parents, formulated relevant research questions and conducted a systematic literature review (SLR). Delphi methodology, informed by SLR results and questionnaires of experts, was used to generate statements aimed at assisting early decision-making and optimising the initial care of patients with HLH/MAS.

RESULTS

The task force developed 6 overarching statements and 24 specific points to consider relevant to early recognition of HLH/MAS, diagnostic approaches, initial management and monitoring of HLH/MAS. Major themes included the simultaneous need for prompt syndrome recognition, systematic evaluation of underlying contributors, early intervention targeting both hyperinflammation and likely contributors, careful monitoring for progression/complications and expert multidisciplinary assistance.

CONCLUSION

These 2022 EULAR/American College of Rheumatology points to consider provide up-to-date guidance, based on the best available published data and expert opinion. They are meant to help guide the initial evaluation, management and monitoring of patients with HLH/MAS in order to halt disease progression and prevent life-threatening immunopathology.

The relationship between serum ferritin level and clinical outcomes in sepsis based on a large public database

This study aimed to investigate the relationship between serum ferritin level and prognosis in sepsis. It also explored the potential prognostic value of serum ferritin for predicting outcomes in sepsis based on a large public database. Sepsis patients in MIMIC-IV database were included. Different models including crude model (adjusted for none), model I (adjusted for age and gender) and model II (adjusted for all potential confounders) were performed. Smooth fitting curves were constructed for exploring the relationships between serum ferritin and mortalities of 28-day, 90-day, 180-day and 1-year. Receiver operator characteristic (ROC) curve analysis was utilized for assessing the predictive value of serum ferritin. 1947 sepsis patients were included. The mortalities of 28-day, 90-day, 180-day and 1-year were 20.18% (n = 393), 28.35% (n = 552), 30.30% (n = 590) and 31.54% (n = 614), respectively. In Model II (adjusted for all potential confounders), for every 1000 ng/ml increment in serum ferritin, the values of OR in mortalities of in 28-day, 90-day, 180-day and 1-year were 1.13 (95% CI 1.07-1.19, P < 0.0001), 1.15 (95% CI 1.09-1.21, P < 0.0001), 1.16 (95% CI 1.10-1.22, P < 0.0001) and 1.17 (95% CI 1.10-1.23, P < 0.0001), respectively. The relationships between serum ferritin level and outcomes were non-linear. The areas under the ROC curve (AUC) of ferritin for predicting mortalities of 28-day, 90-day, 180-day and 1-year were 0.597 (95% CI 0.563-0.629), 0.593 (95% CI 0.564-0.621), 0.595 (95% CI 0.567-0.623) and 0.592 (95% CI 0.564-0.620), respectively. The non-linear relationships between serum ferritin and clinical outcomes in sepsis were found. Serum ferritin had a predictive value for short-term and long-term outcomes in sepsis.

Biomarker diversity in increased inflammation: Secondary hemophagocytic syndrome vs. systemic inflammatory response syndrome

INTRODUCTION

Secondary hemophagocytic syndrome (HPS) and systemic inflammatory response syndrome (SIRS) share similar clinical findings as a result of hyperinflammation. Due to high mortality rates in HPS; it is critical to diagnose promptly. Thus, this study aimed to evaluate the diagnostic and prognostic significance of inflammatory markers in these two increased inflammatory states.

METHODS

We conducted a prospective observational study including patients hospitalized in the intensive care unit of the Internal Medicine Department of Ege University Hospital.

RESULTS

Thirty-three patients with HPS and 46 patients with SIRS were evaluated. Serum ferritin and sIL-2r levels were significantly higher in the HPS group than in the SIRS group, as expected. Receiver operating curve (ROC) analysis showed that the optimal cutoff for ferritin to distinguish HPS from SIRS was 1703 μg/L (sensitivity: 75%, specificity: 94.1%, area under the curve (AUC): 0.871, p < 0.001), and that for sIL-2r was 5888 U/ml (sensitivity: 45.5%, specificity: 89.1%, AUC: 0.698, and p = 0.001). Temporal changes (Δ) in ferritin were determined as a mortality predictor. When evaluated in terms of prognostic significance in ROC analysis, a decrease in ferritin of less than 38% was the cutoff value (sensitivity: 92.3%, specificity: 76.9%, AUC: 0.888, and p < 0.001), in mortality. Contrarily, neither baseline nor temporal change in sIL-2r did not achieve prognostic significance as a mortality predictor.

CONCLUSION

In this single-center study, serum ferritin level was found to be a particularly more valuable diagnostic and prognostic marker than sIL-2r in patients with HPS.

Extreme Hyperferritinemia: Causes and Prognosis

The significance of extreme hyperferritinemia and its association with certain diagnoses and prognoses are not well characterized. We performed a retrospective analysis of adult patients with at least one total serum ferritin (TSF) measurement ≥ 5000 µg/L over 2 years, in three university hospitals. Conditions associated with hyperferritinemia were collected, and patients were classified into 10 etiological groups. Intensive care unit (ICU) transfer and mortality rates were recorded. A total of 495 patients were identified, of which 56% had a TSF level between 5000 and 10,000 µg/L. There were multiple underlying causes in 81% of the patients. The most common causes were infections (38%), hemophagocytic lymphohistiocytosis (HLH, 18%), and acute hepatitis (14%). For TSF levels > 10,000 µg/L, there were no solid cancer or hematological malignancy without another cause of hyperferritinemia. Isolated iron-overload syndromes never exceeded TSF levels > 15,000 µg/L. Extreme hyperferritinemia (TSF levels > 25,000 µg/L) was associated with only four causes: HLH, infections, acute hepatitis and cytokine release syndromes. A total of 32% of patients were transferred to an ICU, and 28% died. Both ICU transfer rate and mortality were statistically associated with ferritin levels. An optimized threshold of 13,405 μg/L was the best predictor for the diagnosis of HLH, with a sensitivity of 76.4% and a specificity of 79.3%. Hyperferritinemia reflects a variety of conditions, but only four causes are associated with extreme hyperferritinemia, in which HLH and acute hepatitis are the most common. Extreme hyperferritinemia has a poor prognosis with increased mortality.

Pediatric hemophagocytic lymphohistiocytosis in a tropical country: Results of a multicenter study in Thailand

BACKGROUND

Hemophagocytic lymphohistiocytosis (HLH) is a rare, life-threatening condition caused by genetic mutation or various triggers disturbing the immune system.

METHODS

A multicenter retrospective study of pediatric patients with HLH receiving a diagnosis between January 2005 and December 2019 from three pediatric oncology centers was conducted to explore the clinical characteristics and determine prognostic factors associated with outcomes among Thai children.

RESULTS

In all, 78 patients with HLH with a median age at diagnosis of 3.17 (range, .08-17.83) years were enrolled. The male to female ratio was 1.2:1. The most common type of HLH was infection-associated hemophagocytic syndrome (IAHS) (n = 59, 75%) of which Epstein-Barr virus was the most common pathogen. Thrombocytopenia, hyperbilirubinemia, and treatment response at weeks 2 and 8 after initiating treatment were associated with mortality. Platelet count <50,000 cells/mm³ was the only independent prognostic factor to define survival outcome (p-value .035). Two-year overall survival rate was 71.3% (95% confidence interval, 59.2%-80.3%). Survival rates between IAHS, malignant associated HLH, macrophage activation syndrome, and unspecific HLH did not significantly differ (p-value .571).

CONCLUSION

IAHS was the most common cause among pediatric HLH in Thailand. The outcomes of Thai children with HLH were comparable to those of developed countries. Platelet count <50,000 cells/mm³ was the only independent prognostic factor to define survival outcome.

Therapeutic potential of induced iron depletion using iron chelators in Covid-19

Ferritin, which includes twenty-four light and heavy chains in varying proportions in different tissues, is primarily responsible for maintaining the body's iron metabolism. Its normal value is between 10 and 200 ngmL^-1 in men and between 30 and 300 ngmL^-1 in women. Iron is delivered to the tissue via them, and they act as immunomodulators, signaling molecules, and inflammatory markers. When ferritin level exceeds 1000 µgL^-1, the patient is categorized as having hyperferritinemia. Iron chelators such as deferiprone, deferirox, and deferoxamine are currently FDA approved to treat iron overload. The inflammation cascade and poor prognosis of COVID-19 may be attributed to high ferritin levels. Critically ill patients can benefit from deferasirox, an iron chelator administered orally at 20-40 mgkg^-1 once daily, as well as intravenous deferoxamine at 1000 mg initially followed by 500 mg every 4 to 12 h. It can be combined with monoclonal antibodies, antioxidants, corticosteroids, and lactoferrin to make iron chelation therapy effective for COVID-19 victims. In this article, we analyze the antiviral and antifibrotic activity of iron chelators, thereby promoting iron depletion therapy as a potentially innovative treatment strategy for COVID-19.

An Unusual Presentation of Glandular Fever

Epstein-Barr virus (EBV) is an ubiquitous DNA herpesvirus with >90% of adults >40 years of age showing a serological response. While in their youth, primary EBV infection may pass unnoticed, young adults have a high incidence of infectious mononucleosis (IM). This is characterized by a triad of pharyngitis, cervical lymphadenopathy, and fever because of a self-limiting lymphoproliferative disease. Common complications include but are not limited to hepatitis, splenomegaly, encephalitis, and haemophagocytic lymphohistiocytosis (HLH) with evidence that Caucasian males and smokers are more likely to suffer severe disease. Here we present a 21-year-old male who presented with a 2-week history of fever, dry cough, and a 4-week history of pharyngitis. He had no exposure to unwell contacts and denied any new sexual partners. Examination revealed general pallor with tender bilateral cervical lymphadenopathy and pharyngeal erythema. Admission bloods revealed pancytopenia (WCC 1.5 × 10⁹/L, Plt 84 × 10⁹/L, and Hb 82 g/L) with normal reticulocyte count and raised mean corpuscular volume (114 fL). Serum vitamin B12 and folate were low with serum ferritin raised (1027 µg/L) suggesting a proinflammatory state. Admission liver function tests, coeliac serology, autoimmune panel (ANA, ANCA, and anti-dsDNA), hepatitic (hepatitis A, B, and E), human immunodeficiency virus (HIV), toxoplasmosis, parvovirus, and CMV serology were normal. The monospot test on day 1 of the presentation was negative. Ultrasound (US) of the abdomen on day 3 of the presentation revealed isolated splenomegaly (16.8 cm). Day 4 EBV serology (VCA IgM, VCA IgG, and EBNA IgG) was negative as such haematological investigations including JAK2, serum free light chains, and BCR-ABL were undertaken alongside cervical lymph node core biopsy. Repeat Monospot testing on day 7 came back positive. Repeat EBV serology now showed equivocal EBV VCA IgG (0.77 OD) and positive VCA IgM (9.04 OD) with concurrent new hepatitis. Histopathology of the core biopsy revealed Sternberg-reed cells and a mixed immunoblastic reaction in keeping with resolving IM. This case highlights the need for physicians to have a strong clinical suspicion of IM and understand the multiple ways in which IM may be present as well as the time lag to positivity in serological testing.

An improved index for diagnosis and mortality prediction in malignancy-associated hemophagocytic lymphohistiocytosis

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening inflammatory syndrome that may complicate hematologic malignancies (HMs). The appropriateness of current criteria for diagnosing HLH in the context of HMs is unknown because they were developed for children with familial HLH (HLH-2004) or derived from adult patient cohorts in which HMs were underrepresented (HScore). Moreover, many features of these criteria may directly reflect the underlying HM rather than an abnormal inflammatory state. To improve and potentially simplify HLH diagnosis in patients with HMs, we studied an international cohort of 225 adult patients with various HMs both with and without HLH and for whom HLH-2004 criteria were available. Classification and regression tree and receiver-operating curve analyses were used to identify the most useful diagnostic and prognostic parameters and to optimize laboratory cutoff values. Combined elevation of soluble CD25 (>3900 U/mL) and ferritin (>1000 ng/mL) best identified HLH-2004-defining features (sensitivity, 84%; specificity, 81%). Moreover, this combination, which we term the optimized HLH inflammatory (OHI) index, was highly predictive of mortality (hazard ratio, 4.3; 95% confidence interval, 3.0-6.2) across diverse HMs. Furthermore, the OHI index identified a large group of patients with high mortality risk who were not defined as having HLH according to HLH-2004/HScore. Finally, the OHI index shows diagnostic and prognostic value when used for routine surveillance of patients with newly diagnosed HMs as well as those with clinically suspected HLH. Thus, we conclude that the OHI index identifies patients with HM and an inflammatory state associated with a high mortality risk and warrants further prospective validation.

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).

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.

The Efficacy of Etoposide-Based Therapy in Adult Secondary Hemophagocytic Lymphohistiocytosis

Data supporting the use of etoposide-based therapy in hemophagocytic lymphohistiocytosis (HLH) arise largely from pediatric studies. There is a lack of comparable data among adult patients with secondary HLH. We conducted a retrospective study to assess the impact of etoposide-based therapy on outcomes in adult secondary HLH. The primary outcome was overall survival. The log-rank test was used to compare Kaplan-Meier distributions of time-to-event outcomes. Multivariable Cox proportional hazards modeling was used to estimate adjusted hazard ratios (HRs) with 95% confidence intervals (CIs). Ninety adults with secondary HLH seen between January 1, 2009, and January 6, 2020, were included. Forty-two patients (47%) received etoposide-based therapy, while 48 (53%) received treatment only for their inciting proinflammatory condition. Thirty-three patients in the etoposide group (72%) and 32 in the no-etoposide group (67%) died during follow-up. Median survival in the etoposide and no-etoposide groups was 1.04 and 1.39 months, respectively. There was no significant difference in survival between the etoposide and no-etoposide groups (log-rank p = 0.4146). On multivariable analysis, there was no association between treatment with etoposide and survival (HR for death with etoposide = 1.067, 95% CI: 0.633-1.799, p = 0.8084). Use of etoposide-based therapy was not associated with improvement in outcomes in this large cohort of adult secondary HLH patients.

Hemophagocytic Lymphohistiocytosis in the Emergency Department: Recognizing and Evaluating a Hidden Threat

Background

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening hematologic disorder resulting from an ineffective and pathologic activation of the immune response system that may mimic common emergency department presentations, including sepsis, acute liver failure, disseminated intravascular coagulation, and flu-like illnesses such as coronavirus disease 2019 (COVID-19).

Objective

This narrative review provides a summary of the disease and recommendations for the recognition and diagnostic evaluation of HLH with a focus on the emergency clinician.

Discussion

Though the condition is rare, mortality rates are high, ranging from 20% to 80% and increasing with delays in treatment. Importantly, HLH has been recognized as a severe variation of the cytokine storm associated with COVID-19. Common features include a history of infection or malignancy, fever, splenomegaly or hepatomegaly, hyperferritinemia, cytopenias, coagulopathies, abnormal liver enzymes, and hypertriglyceridemia. Using specific features of the history, physical examination, laboratory studies, and tools such as the HScore, HLH-2004/2009, and hyperferritinemia thresholds, the emergency clinician can risk-stratify patients and admit for definitive testing. Once diagnosed, disease specific treatment can be initiated.

Conclusion

This review describes the relevant pathophysiology, common presentation findings, and a framework for risk stratification in the emergency department.

Ferritin index is a strong prognostic marker in adult hemophagocytic lymphohistiocytosis

AIMS

The relationship between ferritin levels and survival in adult hemophagocytic lymphohistiocytosis (HLH) has been evaluated in previous studies. However, Admission-to-discharge percentage ferritin reduction (named as ferritin index) level in adult patients with HLH has never been evaluated to predict 6-month survival.

METHODS

The demographic, laboratory and clinical information of 102 newly diagnosed adult HLH patients were collected. Regression analysis, receiver operating curve and Kaplan-Meier curves were analysed to explore the performance of ferritin levels.

RESULTS

Ferritin index and discharge ferritin level were significantly different between survivour and non-survivour group (all P < .001). Ferritin index had the highest area under the curve (AUC) for predicting the survival (AUC = 0.802, P < .001) followed by discharge ferritin (AUC = 0.746, P < .001). Kaplan-Meier analysis showed a significant difference in survival according to optimum cutoff values of ferritin index ≥ 10.19% (P < .001) or discharge ferritin ≤ 1056.1 μg/L (P < .001). Multivariate analysis confirmed that ferritin index and discharge ferritin are independent predictors of 6-month survival (ferritin index: odds ratio (HR) 6.237, 95% confidence interval (CI) 2.075-18.774, P = .001; discharge ferritin: HR 6.024, 95% CI 1.894-19.231, P = .002). In addition, the combination of a ferritin index ≥ 10.19% and discharge ferritin ≤ 1056.1 μg/L had a significantly higher 6-month survival (P < .001).

CONCLUSION

Ferritin index is a better predictor of 6-month survival than admission and discharges ferritin levels in adult patients with HLH.

Biomarkers for Early Diagnosis of Hemophagocytic Lymphohistiocytosis in Critically Ill Patients

Many biomarkers have been proposed for the diagnosis of secondary hemophagocytic lymphohistiocytosis (HLH) in adults, but comparative studies are lacking. We analyzed ferritin, glycosylated ferritin, soluble CD25, CD163 and CD14, IL-6, IFN-γ, IL-18, IL-10, IL-1ß, IL-12p70, IL-17α, IP-10, and CXCL9 levels to differentiate HLH from sepsis in critically ill patients. Of 120 patients, HLH was confirmed for 14 patients. Among the biomarkers tested, ferritin, IL-18, and glycosylated ferritin were the most efficient parameters for early diagnosis of HLH. With a sensitivity set at 85%, ferritin, IL-18, and glycosylated ferritin were the biomarkers with the highest specificity: 84, 79, and 71% respectively. Combining IL-18 with the HScore provided a new score with an increased specificity compared to the HScore alone, 86% compared to 70% with a sensitivity set at 100%. A distinct cytokine pattern was highlighted in patients with malignancy-triggered HLH, with highly increased levels of INF-ɣ and CXCL9, compared to HLH secondary to infection. This is the largest study available to date, comparing diagnostic biomarkers for HLH on a cohort of critically ill adult patients. Serum ferritin was the most discriminating parameter for early diagnosis of secondary HLH. IL18^*HScore was identified as a highly potential score.

Can we truly diagnose adult secondary hemophagocytic lymphohistiocytosis (HLH)? A critical review of current paradigms

The HLH-2004 criteria were initially conceived as inclusion criteria for a clinical trial investigating therapy for (largely primary) pediatric hemophagocytic lymphohistiocytosis (HLH). These criteria have since been extrapolated to diagnose adult secondary HLH despite their questionable generalizability. It remains unclear whether these diagnostic criteria are truly applicable among adult secondary cases, and rigorous evidence for their use among such patients is lacking. This review critically examines the utility of the HLH-2004 criteria for the diagnosis of adult secondary HLH. It is framed as a reappraisal of each of the criteria's individual components, with an assessment of the relevance of, and/or evidence regarding, each. There are clear limitations to these criteria as they apply to adult secondary HLH, however they may help guide our understanding of the disease to some extent. Some new paradigms are emerging for the diagnosis of adult secondary HLH, however these too are limited by the difficulties inherent in formulating specific criteria for a very non-specific syndrome, which lacks any single gold-standard diagnostic test.

Cytomegalovirus pneumonitis-induced secondary hemophagocytic lymphohistiocytosis and SIADH in an immunocompetent elderly male literature review

Hemophagocytic lymphohistiocytosis (HLH) is also known as hemophagocytic syndrome. It is a lethal hematologic condition due to a dysregulated immune response which results in inappropriately activated macrophages damaging host tissues. Based on the etiology, HLH can be primary (genetic) or secondary (acquired). The most common cause of a secondary HLH is an infection. Viral infections are the most common cause of secondary HLH. Among the viral causes of secondary HLH, Epstein–Barr virus is the most common etiologic agent. Cytomegalovirus (CMV) is a common causative pathogen in the immunocompromised host but is rare in an immunocompetent adult. In infection- associated secondary HLH, treatment includes antimicrobial therapy. HLH carries a high mortality and morbidity rate as it is an underdiagnosed clinical condition. Successful early diagnosis allows for adequate time for curative therapy. Treatment for HLH includes chemotherapy, immunomodulators, and a hematopoietic stem-cell transplant. The 2004 diagnostic criteria set by the Histiocyte Society serves as a guide to make an earlier clinical diagnosis. A review of PubMed literature revealed only five reported cases of CMV-induced HLH. We describe the sixth case of CMV pneumonitis-induced HLH and syndrome of inappropriate antidiuretic hormone secretion in a 72-year-old White male. He was treated successfully with oral valganciclovir and corticosteroids.