What's in a name? The heterogeneous clinical spectrum and prognostic factors in a cohort of adults with hemophagocytic lymphohistiocytosis

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.

Investigation of the relationship between red blood cell distribution width and mortality in patients with hemophagocytic lymphohistiocytosis: a retrospective study

BACKGROUND

Red blood cell distribution width (RDW) is related to sepsis-related mortality. Hemophagocytic lymphohistiocytosis (HLH) is a syndrome caused by severe infection, tumors, or autoimmunity without a specific diagnosis.

OBJECTIVE

To explore the correlation between RDW and mortality in patients with HLH.

DESIGN AND SETTING

A retrospective study conducted in a hospital in China.

METHODS

A total of 101 inpatients with HLH from January 1, 2017 to December 31, 2021 were divided into non-survivor (n = 52) and survivor (n = 49) groups. A non-parametric test was used to analyze demographic, clinical, and laboratory data between groups. Independent variables with P < 0.05 were analyzed using binary logistic regression to screen out mortality-related variables. Selected variables were subjected to multivariate logistic regression analysis, and those with strong correlations were screened. Receiver operating characteristic (ROC) curves of strongly correlated variables and area under curve (AUC) values were obtained.

RESULTS

The APACHE II score, RDW, and platelet (PLT) and fibrinogen (FIB) levels (P < 0.05) different significantly. RDW, PLT, FIB were correlated with mortality. The AUC values of RDW, PLT, and FIB were 0.857, 0.797, and 0.726, respectively. RDW was associated with mortality in patients with HLH (P < 0.01, cut-off value: 16.9). The sensitivity and specificity of predicting mortality were 97.96% and 96.1%, respectively.

CONCLUSION

Logistic regression analysis showed a correlation between RDW and patients' mortality. Therefore, RDW can be used to predict mortality in patients with HLH.

High Mortality of HLH in ICU Regardless Etiology or Treatment

Background: Adult hemophagocytic lymphohistiocytosis (HLH) is highly lethal in the ICU. The diagnostic and therapeutic emergency that HLH represents is compounded by its unknown pathophysiological mechanisms. Here, we report on a large cohort of adult HLH in the ICU (ICU-HLH). We analyzed prognostic factors associated with mortality to define the diagnostic and therapeutic challenges in this specific population. Methods: This retrospective study included adult patients diagnosed with HLH in four ICUs in Marseille, France between 2010 and 2020. Patients who fulfilled the HLH-2004 criteria (≥ 4/8) and/or had an HScore ≥ 169 were diagnosed with HLH. HLH was categorized into four groups according to etiology: sepsis-associated HLH, intracellular infection-associated HLH, malignancy-associated HLH, and idiopathic HLH. Results: Two hundred and sixty patients were included: 121 sepsis-associated HLH (47%), 84 intracellular infection-associated HLH (32%), 28 malignancy-associated HLH (11%), and 27 idiopathic HLH (10%). The ICU mortality rate reached 57% (n = 147/260) without a statistical difference between etiological groups. Independent factors associated with mortality in multivariate analysis included age (OR (5 years) = 1.31 [1.16-1.48], p < 0.0001), SOFA score at ICU admission (OR = 1.37 [1.21-1.56], p < 0.0001), degradation of the SOFA score between ICU arrival and HLH diagnosis (Delta SOFA) (OR = 1.47 [1.28-1.70], p < 0.0001), the presence of bone-marrow hemophagocytosis (OR = 5.27 [1.11-24.97], p = 0.04), highly severe anemia (OR = 1.44 [1.09-1.91], p = 0.01), and hypofibrinogenemia (OR = 1.21 [1.04-1.41], p = 0.02). Conclusions: In this large retrospective cohort study of critically ill patients, ICU-HLH in adults was associated with a 57% mortality rate, regardless of HLH etiology or specific treatment. Factors independently associated with prognosis included age, presence of hemophagocytosis in bone-marrow aspirates, organ failure at admission, and worsening organ failure during the ICU stay. Whether a rapid diagnosis and the efficacy of specific therapy improve outcome is yet to be prospectively investigated.

An Atypical Presentation of Hemophagocytic Lymphohistiocytosis (HLH) Secondary to Occult Hodgkin Lymphoma

Hemophagocytic lymphohistiocytosis (HLH) is a rare and life-threatening syndrome of immune system dysregulation characterized by the phagocytosis of various cells by histiocytes in the bone marrow. HLH can present in one of the two ways: primary HLH, which is caused by mutations in genes essential to T and NK-cell function, and secondary HLH, typically caused by Epstein-Barr virus (EBV) infection or malignancy. Because of the rapid progression and high mortality of this disease, prompt diagnosis is essential to good outcomes. Here, we report the 2-month clinical course of a patient who presented with altered mental status and recurrent fever of unknown origin. Initially, he did not meet diagnostic criteria for HLH and had a negative bone marrow biopsy; however, he eventually progressed to full-blown HLH secondary to occult Hodgkin lymphoma. This case is unusual for the slow and smoldering course of the patient's disease and highlights the importance of aggressively searching for potential malignancies to ensure the initiation of definitive therapy as soon as possible.

Understanding of cytokines and targeted therapy in macrophage activation syndrome

Macrophage activation syndrome (MAS) is a potentially life-threatening complication of systemic autoinflammatory/autoimmune diseases, generally systemic juvenile idiopathic arthritis and adult-onset Still's disease. It is characterized by an excessive proliferation of macrophages and T lymphocytes. Recent research revealed that cytokine storm with elevated pro-inflammatory cytokines, including IFN-γ, IL-18, and IL-6, may be central to the pathogenesis of MAS. Though the mainstream of MAS treatment remains corticosteroids and cyclosporine, targeted therapies with anti-cytokine biologics are reported to be promising for controlling systemic inflammation in MAS.

A comprehensive analysis of adult patients with secondary hemophagocytic lymphohistiocytosis: a prospective cohort study

Secondary hemophagocytic lymphohistiocytosis (HLH) is a rare but fatal condition with various underlying disorders in adult patients and is diagnosed based on the HLH-2004 criteria, which were established based on experience in pediatric patients. However, few studies have prospectively evaluated the treatment outcomes and diagnostic performance of HLH criteria in adult patients with secondary HLH. Thus, we performed a single-center, prospective cohort study of adult patients with suspected HLH, and we analyzed treatment outcomes of patients enrolled between 2017 and 2019 as an interim analysis ( ClinicalTrials.gov Identifier: NCT03117010). Of the 73 patients with suspected HLH, 70 patients completed the evaluation for ≥ 7 of the HLH-2004 criteria, and 55 patients were diagnosed with HLH (55/73, 75%). Although serum ferritin and fever had a sensitivity of more than 90%, both had exceptionally low specificity, whereas soluble CD25 had a sensitivity of more than 90% and specificity of 80%. Forty patients with malignancy-associated HLH had B cell (n = 19) or T- or NK-cell (n = 21) lymphoid malignancy, whereas 15 patients had non-malignant disorders. Non-malignancy-associated HLH had greater than 90% 1-year overall survival (OS) after diagnosis of HLH, whereas that for malignancy-associated HLH was less than 40%. In conclusion, our study showed promising treatment outcomes for patients enrolled in our prospective cohort study, and prospectively demonstrated the diagnostic performance of the HLH-2004 criteria in adult patients with suspected HLH. Given that lymphoma was the most common cause of HLH in adults, thorough evaluation for lymphoma should be performed in adults with suspected HLH.