Diagnostic evaluation of patients with suspected haemophagocytic lymphohistiocytosis

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

Introduction

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening immune disorder characterized by uncontrolled lymphocyte and macrophage activation and a subsequent cytokine storm. The timely initiation of immunosuppressive treatment is crucial for survival.

Methods

Here, we harnessed Vγ9Vδ2 T cell degranulation to develop a novel functional assay for the diagnosis of HLH. We compared the novel assay with the conventional natural killer (NK) cell stimulation method in terms of efficiency, specificity, and reliability. Our analysis involved 213 samples from 182 individuals, including 23 samples from 12 patients with degranulation deficiency (10 individuals with UNC13D deficiency, 1 with STXBP2 deficiency, and 1 with RAB27A deficiency).

Results

While both tests exhibited 100% sensitivity, the Vγ9Vδ2 T cell degranulation assay showed a superior specificity of 86.2% (n=70) compared to the NK cell degranulation assay, which achieved 78.9% specificity (n=213). The Vγ9Vδ2 T cell degranulation assay offered simpler technical requirements and reduced labor intensity, leading to decreased susceptibility to errors with faster processing times.

Discussion

This efficiency stemmed from the sole requirement of dissolving (E)-4-hydroxy-3-methyl-but-2-enyl pyrophosphate (HMBPP) powder, contrasting with the intricate maintenance of K562 cells necessary for the NK cell degranulation assay. With its diminished susceptibility to errors, we anticipate that the assay will require fewer repetitions of analysis, rendering it particularly well-suited for testing infants.

Conclusion

The Vγ9Vδ2 T cell degranulation assay is a user-friendly, efficient diagnostic tool for HLH. It offers greater specificity, reliability, and practicality than established methods. We believe that our present findings will facilitate the prompt, accurate diagnosis of HLH and thus enable rapid treatment and better patient outcomes.

Allogeneic hematopoietic stem cell transplant for familial hemophagocytic lymphohistiocytosis: a case report and literature review

Objectives

This study aims to discuss the clinical manifestations and treatment of Familial hemophagocytic lymphohistiocytosis (FHL) caused by a mutation in the UNC13D gene.

Methods

A 6-year-old female child presented with unexplained febricity, splenomegaly, pancytopenia, hemophagocytic lymphohistiocytosis in bone marrow, decreased NK cell activity, soluble CD25 levels > 44000ng/ml. Genetic sequencing revealed a mutation in the UNC13D gene. Additionally, the patient experienced intermittent fever with seizures characterized by involuntary twitching of the left upper limb. Head magnetic resonance imaging (MRI) showed white matter lesions.

Results

According to the HLH-2004 diagnostic criteria revised by the International Society of Histiocytosis the patient was diagnosed with FHL. Despite receiving HLH-2004 treatment, the disease relapsed. However, after a salvage allogeneic Hematopoietic Stem Cell Transplant (HSCT), febricity, abnormal blood cells, and neurological symptoms significantly improved.

Conclusions

Prompt performance of allogeneic HSCT is crucial upon diagnosis of FHL, especially when neurological involvement is present.

[Hemophagocytic lymphohistiocytosis and macrophage activation syndrome : A multidisciplinary challenge]

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening hyperinflammatory syndrome that is characterized by hyperferritinemia, cytopenia, disseminated intravascular coagulopathy and functional disorders of the liver and the central nervous system. The term macrophage activation syndrome is predominantly used for secondary HLH in the context of autoimmune diseases (e.g., systemic juvenile idiopathic arthritis). In addition, malignancies and genetic inborn errors of immunity can predispose to the development of HLH. Infections (e.g., Epstein-Barr virus) in turn represent possible triggers of an acute episode. Due to the unspecific manifestation of the disease, a systematic evaluation of the organ systems is recommended in the clinical and laboratory analytical clarification of hyperinflammatory syndromes. In general, the treatment should be carried out by a multidisciplinary team with expertise in rheumatology, hematological oncology, infectious diseases and intensive care medicine. The primary treatment of HLH usually consists of glucocorticoids and in cases of a rapid deterioration of the condition anakinra (interleukin 1 block) and intravenous immunoglobulins can be employed. Treatment of the underlying disease should be consequently carried out in parallel, together with antimicrobial treatment.

Pregnancy-Associated Onset of Adult-Onset Still's Disease

Objective  This study aims to elucidate the clinical manifestations, diagnostic challenges, and management strategies of adult-onset Still's disease (AOSD) during pregnancy, leveraging a case series overview and a detailed case report from our center. Study Design  A comprehensive review of 21 published case reports on AOSD diagnosed during pregnancy was conducted, alongside a detailed case report of a patient diagnosed and managed at our center. This study emphasizes the importance of recognizing AOSD in pregnant patients, outlines the therapeutic challenges encountered, and discusses the potential complications arising from the disease and its treatment. Results  The onset of AOSD during pregnancy predominantly occurs in the first or second trimester, with a polycyclic disease course observed in most cases. Management primarily involves corticosteroids and immunosuppressive medications, balancing the disease control with potential pregnancy complications. The case report highlights the complex interplay between AOSD, hemophagocytic lymphohistiocytosis, and pregnancy, illustrating a multidisciplinary approach to management that ensured favorable maternal and fetal outcomes despite the significant challenges. Conclusion  AOSD presents unique diagnostic and therapeutic challenges during pregnancy, requiring careful consideration of maternal and fetal health. Early diagnosis, a multidisciplinary approach to care, and judicious use of immunosuppressive therapy are critical for managing AOSD flares and associated complications. Further research is necessary to optimize care for this rare condition in the context of pregnancy.

Colorectal Carcinoma-An Anomalous Trigger of Adult Hemophagocytic Lymphohistiocytosis

Hemophagocytic lymphohistiocytosis (HLH) is a rare but often fatal condition characterized by a hyperinflammatory immune response leading to multiorgan failure. It is predominantly observed in the pediatric population and can be classified as familial or acquired HLH. The latter is more common in adults, often associated with malignancy, infection, or autoimmune diseases. Among acquired HLH cases, hematologic neoplasms account for the majority, with only a few isolated reports documenting solid neoplasms as the cause. Herein, we present a case of adult HLH associated with colorectal adenocarcinoma, which, to the best of our knowledge, is only the second reported case of HLH associated with this type of cancer.

Hemophagocytic Lymphohistiocytosis in the Context of Hematological Malignancies and Solid Tumors

Hemophagocytic lymphohistiocytosis (HLH) has been described for decades in association with malignancies (M-HLH). While its mechanism is unknown, M-HLH has a poor prognosis, ranging from 10% to 30% overall survival. Mature T-cell lymphomas, diffuse large B-cell lymphoma, and Hodgkin lymphoma, with or without viral co-triggers such as Epstein-Barr virus, are among the most frequent underlying entities. Most M-HLH cases occur at the presentation of malignancy, but they may also occur during therapy as a result of immune compromise from chemotherapy (HLH in the context of immune compromise, IC-HLH) and (typically) disordered response to infection or after immune-activating therapies (Rx-HLH, also known as cytokine release syndrome, CRS). IC-HLH typically occurs months after diagnosis in the context of fungal, bacterial, or viral infection, though it may occur without an apparent trigger. Rx-HLH can be associated with checkpoint blockade, chimeric antigen receptor T-cell therapy, or bispecific T-cell engaging therapy. Until recently, M-HLH diagnosis and treatment strategies were extrapolated from familial HLH (F-HLH), though optimized diagnostic and therapeutic treatment strategies are emerging.

Prognostic Factors and Long-term Outcomes in 41 Children With Primary Hemophagocytic Lymphohistiocytosis: Report of a Single-center Experience and Review of the Literature

Hemophagocytic lymphohistiocytosis (HLH) is a rare life-threatening hyperinflammatory syndrome with diverse clinical manifestations leading to major diagnostic and therapeutic difficulties. This study aimed to evaluate clinical manifestations, prognostic factors, and long-term outcomes in children with primary HLH. Forty-one patients diagnosed with primary HLH were retrospectively evaluated for patient characteristics, HLH gene mutations, clinical and laboratory manifestations, prognostic factors, and long-term outcomes. The median age of the patients at the time of diagnosis was 3 months (minimum to maximum: 1 to 144 mo). There were 23 patients who had HLH mutation analysis performed, 10 patients with PRF1 mutation, 6 with STX11 mutation, and 7 with UNC13D mutation. Thirteen patients (31.7%) had central nervous system involvement. No correlation was found between overall survival and central nervous system involvement. The estimated 5-year overall survival for the patient who had hematopoietic stem cell transplantation was 9.4 times better than the patients who did not receive hematopoietic stem cell transplantation (81.3% vs 16.7%; P = 0.001). Median serum sodium and blood urea nitrogen levels were significantly higher in deceased HLH patients compared with surviving HLH patients ( P = 0.043, and P = 0.017, respectively). Primary HLH has a poor outcome with high mortality, which necessitates well-designed and international clinical trials to improve diagnosis, therapy, and long-term outcomes.

Disseminated tuberculosis in rare association with hemophagocytic lymphocytosis - A case report from central India

Hemophagocytic Lymphohistiocytosis (HLH) is an uncommon, diverse and rare genetic hyper-inflammatory syndrome. HLH associated with tuberculosis (TB-HLH) has been described as a clinical and diagnostic quandary. The co-existence leads to significantly higher morbidity and mortality. Our case highlights the presence of disseminated tuberculosis and worsening of the case due to underlying hemophagocytic syndrome leading to rapid deterioration of patient prognosis. Prompt diagnosis and treatment remains help to improve patient management.

The Role of Immune Mechanisms, Inflammatory Pathways, and Macrophage Activation Syndrome in the Pathogenesis of Hemophagocytic Lymphohistiocytosis

This review article describes the pathophysiology of hemophagocytic lymphohistiocytosis (HLH). The condition is characterized by excessive stimulation of inflammatory cytokines, lymphocytes, and macrophages, leading to hyperinflammatory disorder with immune dysfunction. The main clinical and diagnostic features include fever ≥38.5°C, splenomegaly, hyperferritinemia, cytopenia, hypofibrinogenemia, hemophagocytosis on the bone marrow, low or absent of natural killer (NK) cell activity, and elevated soluble CD25. Various immunological and inflammatory mechanisms are involved in the pathogenesis of HLH. Moreover, the condition can result in multisystem organ failure, contributing to the high mortality rate in hospital settings. A thorough literature search was conducted by collecting data from multiple articles published on PubMed, Medline, and Google Scholar. The article discusses the cellular and molecular pathways that lead to HLH. Due to the high rate of morbidity and mortality, early diagnosis needs to be established. More research pertaining to molecular biology, immunology, and the genetics of HLH is needed to explore the effective management and treatment of this rare disorder.

Secondary haemophagocytic lymphohistiocytosis in COVID-19: correlation of the autopsy findings of bone marrow haemophagocytosis with HScore

BACKGROUND

Secondary haemophagocytic lymphohistiocytosis (sHLH) is characterised by a hyper activation of immune system that leads to multiorgan failure. It is suggested that excessive immune response in patients with COVID-19 could mimic this syndrome. Some COVID-19 autopsy studies have revealed the presence of haemophagocytosis images in bone marrow, raising the possibility, along with HScore parameters, of sHLH.

AIM

Our objective is to ascertain the existence of sHLH in some patients with severe COVID-19.

METHODS

We report the autopsy histological findings of 16 patients with COVID-19, focusing on the presence of haemophagocytosis in bone marrow, obtained from rib squeeze and integrating these findings with HScore parameters. CD68 immunohistochemical stains were used to highlight histiocytes and haemophagocytic cells. Clinical evolution and laboratory parameters of patients were collected from electronic clinical records.

RESULTS

Eleven patients (68.7%) displayed moderate histiocytic hyperplasia with haemophagocytosis (HHH) in bone marrow, three patients (18.7%) displayed severe HHH and the remainder were mild. All HScore parameters were collected in 10 patients (62.5%). Among the patients in which all parameters were evaluable, eight patients (80%) had an HScore >169. sHLH was not clinically suspected in any case.

CONCLUSIONS

Our results support the recommendation of some authors to use the HScore in patients with severe COVID-19 in order to identify those who could benefit from immunosuppressive therapies. The presence of haemophagocytosis in bone marrow tissue, despite not being a specific finding, has proved to be a very useful tool in our study to identify these patients.

18F-FDG PET/CT for Identifying the Potential Primary Diseases and Predicting Prognosis of Secondary Hemophagocytic Lymphohistiocytosis in Children

Hemophagocytic lymphohistiocytosis (HLH) is a rare, potentially fatal illness, which can be divided into primary HLH (pHLH) and secondary HLH (sHLH). pHLH can be driven by genetic defections. Moreover, the sHLH is usually be triggered by malignancy or non-malignancy diseases. Sixty-two newly diagnosed sHLH patients with known etiology and those who underwent ¹⁸F-FDG PET/CT examination from July 2018 to December 2020 were retrospectively analyzed. They were divided into malignancy-associated HLH (M-HLH, n = 13) and non-malignancy-associated HLH (NM-HLH, n = 49). The metabolic parameters of the liver (Li), spleen (Sp), bone marrow (BM), lymph nodes (LN), and their ratios to the liver background (LiBG) and mediastinum (M) were compared between two groups. These metabolic parameters were evaluated for correlation with laboratory parameters and prognostic parameters. We found that the SUV_max-LN/Sp/Li and SUV_mean-Sp in M-HLH were significantly higher than those in NM-HLH (P=0.031, 0.035, 0.016,  and 0.032). The malignant disease should be considered when SUVmax-LN was higher than 4.41 (sensitivity 61.5%, specificity 81.6%). Hypermetabolic lesions in extranodal organs were more likely to occur in M-HLH than in NM-HLH (P=0.011). IFN- γ was positively correlated with SUVmax-BM/Li/Sp and SUVmean-BM/Li/Sp (P < 0.05). Ferritin, sCD25, IL-6, and IL-10 were positively correlated with SUVmax-Sp and SUVmean-Sp (P < 0.05). In Epstein-Barr virus-associated HLH (EBV-HLH), the SUV parameters of bone marrow were significantly correlated with a poor 2-week treatment response, overall survival, and event-free survival (P < 0.05). We conclude that some ¹⁸F-FDG PET/CT metabolic parameters can help identify the etiology of sHLH in children and provide directions for further inspection. The malignant disease should be considered when the SUVmax-LN is higher than 4.41 and hypermetabolic lesions occur in extranodal organs. In EBV-HLH, a higher SUV of bone marrow is associated with a poorer prognosis.

Anti-inflammatory Treatment of Kawasaki Disease: Comparison of Current Guidelines and Perspectives

Kawasaki disease (KD), an acute, generalized vasculitis, is associated with an increased risk of coronary heart disease and is the most common cause of acquired heart disease in childhood. The incidence of KD is increasing worldwide. There are numerous international treatment guidelines. Our study aims to perform the first one so far comparison of them. While the gold standard therapy remains still the same (intravenous immunoglobulins and aspirin), there is currently a lack of evidence for choosing optimal treatment for high-risk patients and refractory KD. In this review, we also discuss the treatment of complications of KD and Kawasaki-like phenotypes, present an anti-inflammatory treatment in the light of new scientific data, and present novel potential therapeutic targets for KD.

Thrombotic Microangiopathy Associated with Macrophage Activation Syndrome: A Multinational Study of 23 Patients

OBJECTIVE

To describe the clinical characteristics, treatment, and outcomes of a multinational cohort of patients with macrophage activation syndrome (MAS) and thrombotic microangiopathy (TMA).

STUDY DESIGN

International pediatric rheumatologists were asked to collect retrospectively the data of patients with the co-occurrence of MAS and TMA. Clinical and laboratory features of patients with systemic juvenile idiopathic arthritis (sJIA)-associated MAS and TMA were compared with those of an historical cohort of patients with sJIA and MAS.

RESULTS

Twenty-three patients with MAS and TMA were enrolled: 17 had sJIA, 2 systemic lupus erythematosus, 1 juvenile dermatomyositis, 1 mixed connective tissue disease, and 2 undifferentiated connective tissue disease. Compared with the historical cohort of MAS, patients with sJIA with coexistent MAS and TMA had higher frequencies of renal failure and neurologic involvement, hemorrhage, jaundice, and respiratory symptoms, as well as more severe anemia and thrombocytopenia, higher levels of alanine aminotransferase, lactate dehydrogenase, bilirubin and D-dimer, and lower levels of albumin and fibrinogen. They also required admission to the intensive care unit more frequently. Among patients tested, complement abnormalities and reduced ADAMTS13 activity were observed in 64.3% and 44.4% of cases, respectively. All patients received glucocorticoids. Treatment for TMA included plasma-exchange, eculizumab, and rituximab.

CONCLUSIONS

The possible coexistence of MAS and TMA in rheumatic diseases may be underrecognized. This association should be considered in patients with MAS who develop disproportionate anemia, thrombocytopenia, and lactate dehydrogenase increase, or have multiorgan failure.

Study of the diagnostic criteria for hemophagocytic lymphohistiocytosis in neonatal and pediatric patients with severe sepsis or septic shock

Septic shock is a major public health concern. However, the clinical and laboratory criteria for sepsis overlap with those for hemophagocytic lymphohistiocytosis (HLH), and their differentiation can be challenging. The aim of this study was to compare HLH criteria among patients diagnosed with neonatal sepsis and childhood sepsis and to study the outcomes in patients fulfilling the diagnostic criteria for HLH. A cross-sectional study included 50 neonates and children with severe sepsis and/or septic shock. Clinical and laboratory data and HLH diagnostic criteria were studied in relation to patients outcome. Of all patients, 18% fulfilled three of the eight HLH diagnostic criteria, 2% fulfilled four criteria, and 4% fulfilled five criteria. All patients who fulfilled three or more of the criteria died. Mortality was higher in the presence of more positive HLH criteria and in pediatric age groups. However, the distributions of the HLH criteria were comparable for pediatric and neonatal patients with severe sepsis/septic shock, and their mortality rates were not significantly different when based on the criteria.

A Toolkit and Framework for Optimal Laboratory Evaluation of Individuals with Suspected Primary Immunodeficiency

Knowledge related to the biology of inborn errors of immunity and associated laboratory testing methods continues to expand at a tremendous rate. Despite this, many patients with inborn errors of immunity suffer for prolonged periods of time before identification of their underlying condition, thereby delaying appropriate care. Understanding that test selection and optimal evaluation for patients with recurrent infections or unusual patterns of inflammation can be unclear, we present a document that distills relevant clinical features of immunologic disease due to inborn errors of immunity and related appropriate and available test options. This document is intended to serve the practicing clinical immunologist and, in turn, patients by describing best available test options for initial and expanded immunologic evaluations across the disease spectrum. Our goal is to demystify the process of evaluating patients with suspected immune dysfunction and to enable more rapid and accurate diagnosis of such individuals.

Targeted busulfan-based reduced-intensity conditioning and HLA-matched HSCT cure hemophagocytic lymphohistiocytosis

Reduced-intensity/reduced-toxicity conditioning and allogeneic T-cell replete hematopoietic stem cell transplantation are curative in patients with hemophagocytic lymphohistiocytosis (HLH). Unstable donor chimerism (DC) and relapses are clinical challenges . We examined the effect of a reduced-intensity conditioning regimen based on targeted busulfan to enhance myeloid DC in HLH. The European Society for Bone and Marrow Transplantation-approved reduced-intensity conditioning protocol comprised targeted submyeloablative IV busulfan, IV fludarabine, and serotherapy comprising IV alemtuzumab (0.5-0.8 mg/kg) for unrelated-donor and IV rabbit anti-T-cell globulin for related-donor transplants. We assessed toxicity, engraftment, graft-versus-host disease (GHVD), DC in blood cell subtypes, and overall survival/event-free survival. Twenty-five patients from 7 centers were treated (median age, 0.68 year). The median total dose and cumulative area under the curve of busulfan was 13.1 mg/kg (6.4-26.4) and 63.1 mg/L × h (48-77), respectively. Bone marrow, peripheral blood stem cell, or cord blood transplants from HLA-matched related (n = 7) or unrelated (n = 18) donors were administered. Donor cells engrafted in all patients (median: neutrophils d+20/platelets d+28). At last follow-up (median, 36 months; range, 8-111 months), the median DC of CD15+ neutrophils, CD3+ T cells, and CD16+56+ natural killer cells was 99.5% (10-100), 97% (30-100), and 97.5% (30-100), respectively. Eight patients (32%) developed sinusoidal obstruction syndrome, resolving after defibrotide treatment. The 3-year overall survival and event-free survival rates were both 100%. None of the patients developed acute grade III to IV GHVD. Limited chronic GVHD was encountered in 4%. This regimen achieves excellent results with stable DC in patients with HLH.

Clinical Characteristics and Outcomes of 101 Children with Hemophagocytic Lymphohistiocytosis: A Four-Year Single-Center Experience from Egypt

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening condition, arising either due to genetic mutations or from a variety of underlying diseases. This prospective observational study reports the clinical and laboratory data as well as the outcome of pediatric HLH in Egypt. HLH was diagnosed according to the Histiocyte Society HLH-2004 diagnostic criteria conducted at Alexandria University Children's Hospital over four years. One-hundred-one patients were enrolled (44 males and 57 females), and the median age at presentation was 13.1 months (range: 1 day - 181.4 months). Almost 75% of the patients had consanguineous parents, and one-third had a history of an affected family member (HLH or HLH-like illness). The median time interval between the first HLH symptom and diagnosis was 34 days. At diagnosis, patients were preliminarily classified as having primary HLH in 61% of patients and secondary HLH in 39% of patients. The diagnosis was confirmed genetically in 57 patients. Seventy-eight percent of patients received the HLH-94 and HLH-2004 protocols, only seven patients have undergone hematopoietic stem cell transplantation. The overall survival was 26.4% by the end of the study; the most common cause of death was uncontrolled disease activity. This descriptive study, on a large cohort of pediatric HLH in Africa and the Middle East, sheds some light on the epidemiological characteristics of HLH patients and the available diagnostic and therapeutic tools. The mortality rate was considerably high, highlighting the importance of early diagnosis and initiation of appropriate therapy.

Hemophagocytic lymphohistiocytosis and miliary tuberculosis in a previously healthy individual: a case report

BACKGROUND

Hemophagocytic lymphohistiocytosis (HLH) is a rare heterogenous genetic or acquired hyperinflammatory syndrome associated with a high degree of morbidity and mortality. HLH has clinical manifestations related to abnormal prolonged activation of T lymphocytes and macrophages with an excess of proinflammatory cytokines. The main causes of secondary HLH are malignancies and infectious diseases.

CASE PRESENTATION

The patient was a 54-year-old man, originally from Eastern Africa, who had lived in Northern Europe for 30 years. Here we describe the clinical features, laboratory parameters, diagnostic workup, management and outcome data of a previously healthy 54-year-old man diagnosed with HLH secondary to tuberculosis. The patient was initially treated for a community-acquired pneumonia. He developed multiorgan failure with acute respiratory distress syndrome, hypertransaminasemia, and kidney and bone marrow dysfunction. The clinical course together with a simultaneous increase in serum ferritin raised the suspicion of HLH. The patient fulfilled seven out of eight diagnostic criteria for HLH. A thorough diagnostic workup with respect to HLH and a potential underlying disease was initiated. Cultivation of bronchoalveolar lavage fluid, stool and urine, and polymerase chain reaction of epithelioid cell granulomas in the bone marrow were all positive for Mycobacterium tuberculosis. He was treated for both HLH and tuberculosis, and he survived without any sequelae.

CONCLUSIONS

We present one of few published cases of a patient who survived HLH triggered by miliary tuberculosis. The current case illustrates the need for awareness of these two diagnoses, and the timely initiation of specific and supportive treatment to reduce mortality.

Malignancy-associated hemophagocytic lymphohistiocytosis in children: a 10-year experience of a single pediatric hematology center

Objective: Malignancy-associated hemophagocytic lymphohistiocytosis (M-HLH) in children is a relatively rare but life-threatening secondary hemophagocytic lymphohistiocytosis (sHLH). Until now, only a limited number of cases regarding children with M-HLH has been reported. Methods: We conducted a retrospective study of 27 children with M-HLH, who admitted to our center between July 2007 and October 2019. The clinical data and laboratory data were analyzed. Results: The median age of the children with M-HLH was 7 years. Underlying diseases included myeloid malignancy (n = 6), lymphoid malignancy (n = 18) and unknown type lymphoma (n = 3). The one-year mortality rate was 56%. All patients had persistent fever. The clinical manifestations included hepatomegaly (89%), splenomegaly (67%) and central nervous system symptoms (56%). Thirteen children (48%) had Epstein-Barr virus (EBV) infection. No significant differences were observed between EBV-positive and negative M-HLH patients in terms of most clinical indicators. However, EBV-positive M-HLH patients showed prolonged activated partial thromboplastin time (APTT) and more hemophagocytosis in the bone marrow (BM) in contrast to EBV-negative patients. Eighteen patients (67%) received the HLH-94/04 regimen as the initial treatment. There were no significant differences in the overall survival (OS) between EBV-positive and negative patients. Patients with prolonged APTT had a significantly poorer OS than other patients (p = 0.012). Conclusions: The M-HLH children with EBV infection are more likely to have prolonged APTT and more hemophagocytosis in BM. The M-HLH children had a poor prognosis, especially those with prolonged APTT.

MRI findings of central nervous system involvement in children with haemophagocytic lymphohistiocytosis: correlation with clinical biochemical tests

AIM

To investigate the brain magnetic resonance imaging (MRI) features of children with haemophagocytic lymphohistiocytosis (HLH) with central nervous system (CNS) involvement, and to investigate the correlation with clinical biochemical tests.

MATERIAL AND METHODS

Clinical and MRI data were collected from 118 children with HLH-CNS between January 2012 and June 2019. Patients were grouped according to their MRI findings, and statistical methods were used to test for correlations between the MRI findings and biochemical variables.

RESULTS

Patients were divided into three groups, including normal appearance (Group 1, 17/118), diffuse parenchymal volume loss (Group 2, 44/118), and brain parenchyma lesions (Group 3, 57/118) containing three subtypes of brain lesions and HLH-CNS complications. Comparing biochemical values among the three groups revealed a significant difference for all values (p<0.05), except for cell counts in the cerebrospinal fluid (CSF). A pairwise comparison further showed significant inter-group differences for most of the variables. Spearman's rank correlation coefficient also demonstrated that CSF cell counts (r=0.193, p=0.036), CSF microprotein content (r=0.379, p<0.001), serum aspartate aminotransferase (AST; r=0.521, p<0.001), serum lactate dehydrogenase (LDH; r=0.514, p<0.001) and activated partial thromboplastin time (APTT; r=0.326, p<0.001) correlated positively with the MRI groups, while platelet count (PLT; r=-0.633, p<0.001) and plasma fibrinogen (FIB; r=-0.258, p=0.005) correlated negatively.

CONCLUSION

Classification of brain MRI findings of HLH-CNS correlates well with the results of several key biochemical tests. Brain MRI is a promising method to elucidate illness severity and clinical outcomes.

Hematopoietic Stem Cell Transplantation Beyond Severe Combined Immunodeficiency: Seeking a Cure for Primary Immunodeficiency

Hematopoietic stem cell transplantation (HSCT) can provide definitive therapy for patients with primary immunodeficiency disease (PIDD). Modern HSCT techniques and supportive care have significantly improved outcomes for patients with PIDD. This review examines current HSCT practice for PIDD other than severe combined immunodeficiency, and explores indications, risks, and long-term outcomes for this group of challenging diseases.

Macrophage Activation in COVID-19 Patients in Intensive Care Unit

We report six cases of patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, admitted to intensive care unit (ICU), for whom bone marrow aspirate revealed hemophagocytosis. We compared their clinical presentation and laboratory findings to those that can be encountered during a hemophagocytic lymphohistiocytosis. These observations might evoke a macrophage activation mechanism different from the one encountered in the hemophagocytic lymphohistiocytosis (HLH).

Hemophagocytic syndrome with severe sepsis caused by Capnocytophaga canimorsus

Capnocytophaga canimorsus, commonly transmitted by dog bites, can cause severe sepsis, and the mortality rate is very high. We experienced a case of hemophagocytic lymphohistiocytosis (HLH) complicated by severe sepsis caused by C. canimorsus. A 58-year-old man with no remarkable medical history was admitted to another hospital with fever and mild consciousness disorder developed 3 days after being bitten by his dog. The next day, the patient developed disseminated intravascular coagulation and shock and was transferred to our emergency medical center. Blood tests showed hyperferritinemia and cytopenia, and bone marrow aspiration was performed. As a result, we diagnosed severe sepsis and HLH. Once antibiotic and steroid therapy was started, the patient's infection and cytopenia improved. Unfortunately, the patient's fingers and toes required amputation, but his life was saved, and he was discharged from hospital. Because HLH may be hidden in such cases, it may be necessary to measure serum ferritin and perform bone marrow aspiration if hyperferritinemia is suspected.

Development and validation of the prognostic value of ferritin in adult patients with Hemophagocytic Lymphohistiocytosis

Background

Hemophagocytic Lymphohistiocytosis (HLH) is a rare clinical syndrome with high mortality rate. The diagnosis of HLH draws on a constellation of clinical and laboratory abnormalities including extremely high serum ferritin levels. However, no biomarker has been firmly established as a clinically useful prognostic tool in HLH patients. We aimed to perform a retrospective analysis of two independent cohorts to explore the prognostic value of discharge serum ferritin for newly diagnosed adult HLH patients who recently started treatment. The prognostic value of serum ferritin levels at discharge (will be called as post-treatment ferritin level) was initially evaluated in a “test cohort” of 161 previously untreated consecutive adult HLH patients. It was then validated in a second cohort of 68 consecutive previously untreated patients (validation cohort).

Results

Multivariate analysis revealed that significantly high post-treatment serum ferritin levels (>1050 μg/L) were associated with a higher risk of death and poor overall survival in the test cohort (hazard ratio (HR): 3.176, 95% confidence interval (CI) 1.468–6.869, P = 0.003), and the validation cohort (HR: 13.412, 95%CI 1.716–104.816, P = 0.013). At 6-month follow-up period in the test cohort, patients with a > 81% decrease in the serum ferritin level had a significantly higher probability of survival when compared with the patients with ≥14% increase in the serum ferritin level (94% vs. 31%, P < 0.001). Similar findings were observed on the analysis of the decrease in the serum ferritin level in the validation cohort.

Conclusions

These results suggest that the serum ferritin level can be used as an independent prognostic marker in the adult HLH patients.

Hemophagocytic lymphohistiocytosis in adults: collaborative analysis of 137 cases of a nationwide German registry

Purpose

Hemophagocytic lymphohistiocytosis (HLH) is a severe hyperinflammatory syndrome emerging from a deregulated immune response due to various triggers. In adults, systematic data are sparse, which is why recommendations on diagnosis and management have been adopted from pediatric guidelines. A nationwide clinical registry with associated consulting service as collaborative initiative of HLH-specialized pediatricians and hematologists was initiated to better characterize HLH in adults.

Methods

Patients with proven or suspected HLH were registered by 44 institutions. Both HLH-2004 diagnostic criteria and the HScore (www.saintantoine.aphp.fr/score/) were used to confirm HLH diagnosis. Data referring to underlying disease, treatment, outcome, clinical presentation and laboratory findings were recorded.

Results

The study included 137 patients and provides the first systematic data on adult HLH in Germany. Median age was 50 years with a wide range (17–87 years), 87 patients (63.5%) were male. Most common triggering diseases were infections in 61 patients (44.5%) and malignancies in 48 patients (35%). Virtually all patients had elevated ferritin concentrations, and 74% had peak concentrations greater than 10,000 µg/l. At time of analysis, 67 of 131 patients (51%) had died. Patients with malignancy-associated HLH had the shortest median survival (160 days), however no statistically significant difference between subgroups was observed (p = 0.077). Platelets under 20*10⁹/l and low albumin concentrations (< 20 g/l) were associated with poor overall and 30-day survival.

Conclusion

Close multidisciplinary case consultation and cooperation is mandatory when treating adult HLH patients. Early contact with reference centers is recommended, especially in relapsing or refractory disease.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00432-020-03139-4.

Serum soluble VSIG4 as a surrogate marker for the diagnosis of lymphoma-associated hemophagocytic lymphohistiocytosis

Lymphoma-associated haemophagocytic lymphohistiocytosis (L-HLH) is characterized by excessively activated macrophages and cytotoxic T lymphocytes, but few reliable markers for activated macrophages are available clinically. This study, designed to discover novel biomarkers for the diagnosis of lymphoma patients with L-HLH, was initiated between 2016 and 2018. Fifty-seven adult lymphoma patients were enrolled - 39 without HLH and 18 with HLH. The differential serum protein expression profile was first screened between lymphoma patients with and without L-HLH by a quantitative mass spectrometric approach. Soluble V-set and immunoglobulin domain-containing 4 (sVSIG4), specifically expressed by macrophages, was significantly upregulated in the L-HLH group. Subsequently, sVSIG4 concentration was confirmed by enzyme-linked immunosorbent assay to be significantly increased in lymphoma patients with L-HLH. When it was exploited for the diagnosis of lymphoma patients with L-HLH, the area under a receiver operating characteristic curve was 0·98 with an optimal cut-off point of 2195 pg/ml and the corresponding sensitivity and specificity were 94·44% and 94·87% respectively. In addition, the one-year overall survival was significantly worse in patients with a sVSIG4 concentration above 2195 pg/ml compared with those below 2195 pg/ml (5·3% vs. 72·2%, P < 0·0001). sVSIG4 may be a surrogate marker of activated macrophages for the diagnosis of lymphoma patients with L-HLH.

An overview of how on-call consultant paediatricians can recognise and manage severe primary immunodeficiencies

Severe primary paediatric immunodeficiency syndromes are rare and potentially fatal unless suspected, diagnosed and treated early. We provide clinical guidance and support for on-call consultant paediatricians working in secondary level hospitals on how to recognise and manage children with these conditions. Our paper addresses four conditions that risk the most severe outcomes if they are not adequately cared for during on-call periods, such as weekends: severe combined immunodeficiency, haemophagocytic lymphohistiocytosis, severe congenital neutropaenia and chronic granulomatous disease. CONCLUSION: On-call paediatricians are provided with advice on handling the most severe primary immunodeficiencies.

Natural Killer Cell Function Tests by Flowcytometry-Based Cytotoxicity and IFN-γ Production for the Diagnosis of Adult Hemophagocytic Lymphohistiocytosis

Although natural killer (NK) cell function is a hallmark of hemophagocytic lymphohistiocytosis (HLH), there is no standard method or data on its diagnostic value in adults. Thus, we performed a single-center retrospective study of 119 adult patients with suspected HLH. NK cell function was determined using both flowcytometry-based NK-cytotoxicity test (NK-cytotoxicity) and NK cell activity test for interferon-gamma (NKA-IFNγ). NK cell phenotype and serum cytokine levels were also tested. Fifty (42.0%) HLH patients showed significantly reduced NK cell function compared to 69 non-HLH patients by both NK-cytotoxicity and NKA-IFNγ (p < 0.001 and p = 0.020, respectively). Agreement between NK-cytotoxicity and NKA-IFNγ was 88.0% in HLH patients and 58.0% in non-HLH patients. NK-cytotoxicity and NKA-IFNγ assays predicted HLH with sensitivities of 96.0% and 92.0%, respectively. The combination of NKA-IFNγ and ferritin (>10,000 µg/L) was helpful for ruling out HLH, with a specificity of 94.2%. Decreased NK-cytotoxicity was associated with increased soluble IL-2 receptor levels and decreased CD56dim NK cells. Decreased NKA-IFNγ was associated with decreased serum cytokine levels. We suggest that both NK-cytotoxicity and NKA-IFNγ could be used for diagnosis of HLH. Further studies are needed to validate the diagnostic and prognostic value of NK cell function tests.

Hemophagocytic Lymphohistiocytosis: Potentially Underdiagnosed in Intensive Care Units

BACKGROUND

Hemophagocytic lymphohistiocytosis in adults (aHLH) is a rare life-threatening hyperinflammatory syndrome caused by excessive activation of macrophages and CD8+ T-cells. Due to the clinical overlap with severe sepsis, aHLH often remains undiagnosed resulting in poor outcome. Here, we present a retrospective study of incidence, clinical findings, and the outcome of aHLH in intensive care units (ICUs).

METHODS

This retrospective analysis was performed at the university hospital Charité - Universitätsmedizin Berlin. We gathered data from 556 out of 46,532 patients admitted to our anesthesiological ICUs between 2006 and 2013, who had at least one plasma ferritin measurement during ICU treatment, and were at least 18 years old. Of these, 244 patients with ferritin at least 500 μg/L and available datasets of at least 4 HLH-2004 criteria were included. HLH-2004 diagnostic criteria and the recently published HScore were used. An aHLH expert team retrospectively reviewed the potential aHLH cases.

RESULTS

Seventy-one of the included 244 patients died; 9 out of the 244 patients were retrospectively classified as aHLH of whom 4 patients had died (44.4%). Two of the 9 aHLH patients had been correctly diagnosed and had received specific aHLH treatment. Thus, 7 out of 9 patients (77.8%) remained undetected. ICU patients with at least 1 captured ferritin value and hyperferritinemia showed an aHLH rate of 3.7%, which rises up to 5.6% when only deceased patients are considered. Mortality in this selected cohort is 44.4%.

CONCLUSIONS

Overall, 7 out of 9 patients (77.8%) suffering from aHLH remained undiagnosed. Awareness of this life-threatening syndrome, especially in ICUs, should be raised. The inclusion of ferritin into the admission lab panel for ICU is warranted.Clinical trial registered with www.ClinicalTrials.gov (NCT02854943) on August 1, 2016. As this is a retrospective study, trial registration was after final data collection date.

Macrophage Activation Marker Soluble CD163 Associated with Fatal and Severe Ebola Virus Disease in Humans1

Ebola virus disease (EVD) is associated with elevated cytokine levels, and hypercytokinemia is more pronounced in fatal cases. This type of hyperinflammatory state is reminiscent of 2 rheumatologic disorders known as macrophage activation syndrome and hemophagocytic lymphohistiocytosis, which are characterized by macrophage and T-cell activation. An evaluation of 2 cohorts of patients with EVD revealed that a marker of macrophage activation (sCD163) but not T-cell activation (sCD25) was associated with severe and fatal EVD. Furthermore, substantial immunoreactivity of host tissues to a CD163-specific antibody, predominantly in areas of extensive immunostaining for Ebola virus antigens, was observed in fatal cases. These data suggest that host macrophage activation contributes to EVD pathogenesis and that directed antiinflammatory therapies could be beneficial in the treatment of EVD.

A Rare Case of Hemophagocytic Lymphohistiocytosis Associated With Myelodysplastic Syndrome and Trisomy 8 in a Pediatric Patient

Hemophagocytic lymphohistiocytosis (HLH) is a rare disease resulting in clinical and biochemical manifestations of extreme inflammation. Myelodysplastic syndrome (MDS) represents a heterogenous group of clonal hematopoietic disorders. The development of MDS is common in children with trisomy of chromosome 8. Here, we report a fatal case of 8-year-old girl who was admitted to the emergency department with status epilepticus, and later diagnosed with HLH associated with MDS and trisomy of chromosome 8. We believe this is the first reported case of HLH associated with MDS and trisomy 8 in a pediatric patient.

Neonatal Cholestasis: A Pandora's Box

Neonatal cholestasis (NC) is a diagnostic dilemma frequently countered in a neonatal care unit. Early diagnosis is vital for achieving an optimal patient outcome as many causes of cholestasis such as biliary atresia are time-sensitive and amenable to treatment if analyzed and treated early. Nonetheless, it is not generally simple to analyze these cases right on time as some of them are regularly missed due to the presence of pigmented stools, lack of newborn metabolic screening, and named as instances of prolonged jaundice. In this manner, we prescribe to explore all reasons for prolonged jaundice stretching out past 14 days in neonates. Besides, we suggest that stool card ought to be a piece of release rundown for all newborn children being released from the nursery. This is of most extreme significance in the nation like India where guaranteeing customary follow-up is as yet a tough assignment. These stool cards will help in the early determination of patients with NC particularly biliary atresia and guarantee their auspicious cure. Another reason which needs exceptional say is parenteral nutrition–associated liver illness, as the proportion of preterm babies is getting greater and greater with better neonatal care. These extreme preterm infants are in the requirement for prolonged (>14 days) total parenteral nourishment because of which they are at high hazard for NC contrasted with their more developed peers. In this survey, we will give an understanding of clinical approach, differential diagnosis, and clinical review of NC.

Fludarabine/Melphalan 100 mg/m2 Conditioning Therapy Followed by Allogeneic Hematopoietic Cell Transplantation for Adult Patients with Secondary Hemophagocytic Lymphohistiocytosis

Our previous research indicated that a reduced-intensity conditioning regimen (fludarabine and melphalan at 100 mg/m²) was useful in allogeneic hematopoietic cell transplantation (HCT) for patients with lymphoma. This retrospective study evaluated the reduced-intensity conditioning regimen in allogeneic HCT for adult patients with hemophagocytic lymphohistiocytosis (HLH). Sixteen patients with HLH were evaluated, including 6 patients who were enrolled in a prospective clinical trial (NCT00772811) and 10 patients who received the same conditioning regimen (fludarabine at 30 mg/m²/day on days -6 to -2 and melphalan at 100 mg/m² on day -2). The median age was 42 years (range, 18 to 64), and 12 patients had Epstein-Barr virus (EBV)-associated HLH. Donors were an HLA matched sibling for 10 patients, an unrelated matched volunteer for 4 patients, and a mismatched family member for 2 patients. After excluding 3 patients who died soon after HCT, 12 patients achieved an engraftment (neutrophil median, day 12; platelet median, day 16). Five patients experienced acute graft-versus-host disease (GVHD), including 1 case of grade II and 4 cases of grades III to IV. Chronic GVHD occurred in 3 patients (moderate, 1 case; severe, 2 cases). After a median follow-up of 33.8 months 1 patient progressed, 3 patients relapsed, and 9 patients died. Five deaths were unrelated to relapse or progression and were caused by infection (n = 3), bleeding (n = 1), and GVHD (n = 1). No deaths or relapses were observed at >124 days post-transplant. The overall survival rate was 48.6%, and significant differences were observed according to pretransplant ferritin level (P = .007) and cytopenia lineage (P = .021). Before allogeneic HCT 10 of 12 patients still tested positive for EBV DNA: 6 patients tested negative for EBV DNA after HCT, 2 patients had persistent EBV DNA, and 2 patients were unassessable because of early death. Conditioning therapy using a lower dose of melphalan combined with fludarabine appears to be promising in allogeneic HCT for adults with HLH. However, strategies are needed to reduce the risk of early death.

Fatal Septic Shock in a Patient with Hemophagocytic Lymphohistiocytosis Associated with an Infectious Mononucleosis

The authors describe the case of a young woman who developed a clinical pictures resembling a septic shock-related multiple organ dysfunction syndrome a couple of months after having been diagnosed suffering from a hemophagocytic lymphohistiocytosis associated with an infectious mononucleosis. Despite the aggressive treatment, which included antibiotics, vasopressors, IV immunoglobulins, and the use of an extracorporeal device aimed to remove mediators released both during sepsis and the cytokine storm determined by the hemophagocytic lymphohistiocytosis, the patient died. At the autopsy, an extremely uncommon aggressive lymphoma of Epstein-Barr virus-positive T-lymphocytes with systemic involvement was discovered.

[CME: Acquired Hemophagocytic Lymphohistiocytosis]

CME: Acquired Hemophagocytic Lymphohistiocytosis Abstract. Acquired hemophagocytic lymphohistiocytosis comprises a heterogenous group of hyperinflammatory immunoreactions often resulting in uncontrolled immune responses, mainly throughout proliferation of cytotoxic T cells and hemophagocytosis by macrophages. Hemophagocytic lymphohistiocytosis is often underdiagnosed, contributing to its high morbidity and mortality. A systematic diagnostic approach and the use of established diagnostic criteria should lead to an early diagnosis, which is crucial for any therapeutic attempt to achieve a curative state of the disease.

Cytomegalovirus reactivation in a critically ill patient: a case report

Background

The aim of this case report is to discuss diagnostic workup and clinical management of cytomegalovirus reactivation in a critically ill immunocompetent pediatric patient.

Case presentation

A 2-year-old white boy who had no medical history presented with respiratory distress and fever. His Pediatric Risk of Mortality and Pediatric Logistic Organ Dysfunction scores were 20 and 11, respectively. Our preliminary diagnosis was multiple organ dysfunction secondary to sepsis. Antibiotic treatment was started; he was intubated and artificially ventilated. Norepinephrine infusion was started. Hemophagocytic lymphohistiocytosis was diagnosed because our patient had elevated levels of serum ferritin, bicytopenia, splenomegaly, fever (> 38.5 °C), and hemophagocytosis shown in a bone marrow sample. Therapeutic plasma exchange and intravenously administered high-dose corticosteroid for hemophagocytic lymphohistiocytosis and continuous renal replacement treatment for acute renal failure were initiated. Following 5-day high-dose corticosteroid administration, therapeutic plasma exchange, and continuous renal replacement treatment, his clinical status and kidney and liver functions improved, and vasoactive requirement and ferritin levels decreased. He was extubated on the seventh day. On the tenth day of hospitalization he had a seizure and was diagnosed as having septic encephalopathy. His immune functions were found to be normal. Although his medical condition improved continuously, he had left spontaneous pneumothorax on the 21st day of admission as a complication of necrotizing pneumonia. Since pneumothorax persisted, left upper lobectomy surgery was performed on the 30th day of hospitalization. In the pathological examination of the excised lung tissue, features of cytomegalovirus infection were observed. Ganciclovir treatment was started. Serological tests indicated that our patient had cytomegalovirus reactivation. Antiviral treatment was stopped after 17 days, when cytomegalovirus deoxyribonucleic acid (DNA) polymerase chain reaction results became negative. He fully recovered and was discharged on the 50th day of admission.

Conclusions

Cytomegalovirus reactivation in critically ill patients is a prevalent problem and shown to be associated with higher mortality and morbidity. In a case of serologic detection of cytomegalovirus reactivation without any clinical sign of infection, pre-emptive treatment could be considered with assessment of risks and benefits for each patient. Antiviral therapy is highly recommended for patients who have risk factors identified.

[Rheumatoid symptoms in patients with hematologic neoplasms]

Paraneoplastic syndromes in lymphatic or myeloid neoplasms can present with musculoskeletal symptoms, vasculitis-like or febrile symptoms. Hematologic diseases are also associated with rheumatic diseases whereas inflammatory rheumatic diseases are often associated with an increased risk for lymphoproliferative disease. Atypical disease characteristics, lack of disease-specific antibodies or therapeutic response are red flags for diagnosing paraneoplastic or coexistent malignant diseases. New onset of systemic symptoms, worsening of general condition, night sweats or weight loss need to be considered during follow-up and differential diagnostics. This article focuses on musculoskeletal, vasculitis-like and systemic signs of lymphatic or myeloid neoplasms either because of coexistency, tumor association or paraneoplastic disease.

The influence of various therapeutic regimens on early clinical and laboratory response and outcome of children with secondary hemophagocytic lymphohistiocytosis

INTRODUCTION

Secondary hemophagocytic lymphohistiocytosis (sHLH) is a life-threatening syndrome of severe hyperinflammation which is often triggered by infection or autoimmune disease (macrophage activation syndrome - MAS). The aim of our study was to assess the frequency of sHLH/MAS in children treated in our institution and to compare the effectiveness of various therapeutic interventions.

MATERIAL AND METHODS

Between 2005 and 2013, 24 children (age: 1-17 years) were consecutively treated for sHLH/MAS. Therapy was based on glucocorticoids (GCs) in high or standard doses (hd-GCs or sd-GCs), intravenous immunoglobulin (IVIG), and cyclosporin A (CyA). A comparison of selected laboratory and clinical parameters during the first 72 h of treatment and after a week from the last intervention applied in the first 72 h after diagnosis was performed retrospectively.

RESULTS

The majority of patients (14/24, 58%) suffered from sHLH/MAS in the course of an autoimmune disease (12 patients diagnosed with a systemic form of juvenile idiopathic arthritis). We found with a confidence level of 95% that the application of hd-GCs in the first 24 h caused rapid alleviation of fever, reduction of hepatosplenomegaly, and an increase in thrombocytes and s-fibrinogen concentrations. The use of combination therapy with hd-GCs, IVIG, and CyA in the first 72 h caused a faster increase in s-fibrinogen. All patients survived and were alive at the follow-up of 1-8 years.

CONCLUSIONS

The results indicate that treatment of sHLH/MAS based on hd-GCs, CyA and IVIG is an effective therapy in children.

Soluble interleukin-2 receptor is a sensitive diagnostic test in adult HLH

Serum soluble interleukin-2 receptor (sIL-2r) is an important disease marker in hemophagocytic lymphohistiocytosis (HLH), but there are no published data on its diagnostic value in adults. We conducted a single-center retrospective study of 78 consecutive adults who had sIL-2r measured for suspected HLH. Serum sIL-2r levels were measured by enzyme-linked immunosorbent assay (adult reference range, 241-846 U/mL). There were 38 patients with HLH and 40 with a non-HLH diagnosis (such as sepsis, liver disease, histiocyte disorders, autoimmune disease, leukemia, or lymphoma). The receiver operating characteristic curve demonstrated that sIL-2r is a good to excellent diagnostic test for adult HLH, with an area under the curve (AUC) of 0.90 (95% confidence interval, 0.83-0.97) compared with AUC 0.78 (95% confidence interval, 0.67-0.88) for ferritin. The optimal threshold for sIL-2r was 2515 U/mL (sensitivity, 100%; specificity, 72.5%). Although there was a large indeterminate range for sIL-2r, a level of 2400 U/mL or less was helpful for ruling out HLH (sensitivity, 100%), and more than 10 000 U/mL was helpful for ruling in HLH (specificity, 93%). Higher mean sIL-2r levels were seen in malignancy-associated HLH (20 241 U/mL) compared with infection-associated HLH and macrophage activation syndrome (9720 and 5008 U/mL, respectively; P < .05). Levels above 10 000 U/mL were not associated with worse prognosis in patients with HLH. Serum sIL-2r is a sensitive test for diagnosis of adult HLH, but is not as specific as previously reported in children. Additional studies enriched with patients without HLH who have conditions associated with T-cell activation, such as lymphoma and autoimmune lymphoproliferative syndrome, are needed.

Weiss J, Weitzman S, Wouters C, Wulffraat N, Zletni M, Arico M, Egeler RM, Filipovich AH, Gadner H, Imashuku S, Janka G, Ladisch S, McClain KL, Webb D. Development and Initial Validation of the Macrophage Activation Syndrome/Primary Hemophagocytic Lymphohistiocytosis Score, a Diagnostic Tool that Differentiates Primary Hemophagocytic Lymphohistiocytosis from Macrophage Activation Syndrome

OBJECTIVE

To develop and validate a diagnostic score that assists in discriminating primary hemophagocytic lymphohistiocytosis (pHLH) from macrophage activation syndrome (MAS) related to systemic juvenile idiopathic arthritis.

STUDY DESIGN

The clinical, laboratory, and histopathologic features of 362 patients with MAS and 258 patients with pHLH were collected in a multinational collaborative study. Eighty percent of the population was assessed to develop the score and the remaining 20% constituted the validation sample. Variables that entered the best fitted model of logistic regression were assigned a score, based on their statistical weight. The MAS/HLH (MH) score was made up with the individual scores of selected variables. The cutoff in the MH score that discriminated pHLH from MAS best was calculated by means of receiver operating characteristic curve analysis. Score performance was examined in both developmental and validation samples.

RESULTS

Six variables composed the MH score: age at onset, neutrophil count, fibrinogen, splenomegaly, platelet count, and hemoglobin. The MH score ranged from 0 to 123, and its median value was 97 (1st-3rd quartile 75-123) and 12 (1st-3rd quartile 11-34) in pHLH and MAS, respectively. The probability of a diagnosis of pHLH ranged from <1% for a score of <11 to >99% for a score of  ≥123. A cutoff value of ≥60 revealed the best performance in discriminating pHLH from MAS.

CONCLUSION

The MH score is a powerful tool that may aid practitioners to identify patients who are more likely to have pHLH and, thus, could be prioritized for functional and genetic testing.

Effective Immunological Guidance of Genetic Analyses Including Exome Sequencing in Patients Evaluated for Hemophagocytic Lymphohistiocytosis

We report our experience in using flow cytometry-based immunological screening prospectively as a decision tool for the use of genetic studies in the diagnostic approach to patients with hemophagocytic lymphohistiocytosis (HLH). We restricted genetic analysis largely to patients with abnormal immunological screening, but included whole exome sequencing (WES) for those with normal findings upon Sanger sequencing. Among 290 children with suspected HLH analyzed between 2010 and 2014 (including 17 affected, but asymptomatic siblings), 87/162 patients with "full" HLH and 79/111 patients with "incomplete/atypical" HLH had normal immunological screening results. In 10 patients, degranulation could not be tested. Among the 166 patients with normal screening, genetic analysis was not performed in 107 (all with uneventful follow-up), while 154 single gene tests by Sanger sequencing in the remaining 59 patients only identified a single atypical CHS patient. Flow cytometry correctly predicted all 29 patients with FHL-2, XLP1 or 2. Among 85 patients with defective NK degranulation (including 13 asymptomatic siblings), 70 were Sanger sequenced resulting in a genetic diagnosis in 55 (79%). Eight patients underwent WES, revealing mutations in two known and one unknown cytotoxicity genes and one metabolic disease. FHL3 was the most frequent genetic diagnosis. Immunological screening provided an excellent decision tool for the need and depth of genetic analysis of HLH patients and provided functionally relevant information for rapid patient classification, contributing to a significant reduction in the time from diagnosis to transplantation in recent years.

Critically Ill Children With Hemophagocytic Lymphohistiocytosis: A Case Series of 14 Patients

Children with hemophagocytic lymphohistiocytosis (HLH) are at an increased risk of critical illness. In this study, we described the clinical characteristics of critically ill children with HLH and identify factors associated with poor clinical outcomes. Children who were diagnosed with HLH with emergent admission to Children's Intensive Care Unit (CICU) between January 1, 2000 and October 31, 2015 were included. The primary outcome was CICU mortality. Over the 15-year period, there were 14 critically ill patients with HLH with 23 CICU admissions. Median age at HLH diagnosis was 8.2 years (interquartile range [IQR], 2.9 to 11.3). Overall CICU mortality was 8 of 23 CICU admissions (34.8%). Factors that were associated with CICU mortality in critically ill children with HLH identified in this study include: a worse median pediatric index of mortality 2 score (4.7% in survivors [IQR, 2.9% to 11.6%] vs. 2.4% [IQR, 1.2% to 4.3%]; P=0.031); higher median peak serum lactate level (mmol/L) within 24 hours of admission (5.6 [IQR, 2.7 to 17.4] vs. 1.6 [IQR, 1.2 to 2.8]; P=0.032); the need for mechanical ventilation (100% vs. 46.7%; P=0.019); inotropic support (87.5% vs. 20.0%; P=0.006); renal replacement therapy (50% vs. 0%; P=0.008); and blood product transfusion episodes (24.5 [IQR, 14.3 to 46.8] vs. 3.0 [IQR, 1.0 to 9.0]; P=0.002). Further studies are required to validate the factors that are associated with poor outcomes in critically ill children with HLH.

A systematic review of malignancy-associated hemophagocytic lymphohistiocytosis that needs more attentions

As an infrequent but potentially life-threatening hyperinflammatory syndrome, hemophagocytic lymphohistiocytosis (HLH) is clinically characterized with prolonged fever, hepatosplenomegaly, cytopenia, hypertriglyceridemia, hyperferritinemia and hemophagocytosis in bone marrow, liver, spleen or lymph nodes. Malignancy-associated HLH (M-HLH), one type of acquired HLH, usually presents variable overlaps of symptoms with other types of HLH, thus resulting in higher incidence of misdiagnosis and mortality. In recent years, with the increasing awareness to this disease, the diagnosis and management of HLH have gained more and more attention, and improvements have been made accordingly. As a result, the survival of patients is greatly prolonged. However, there is still no consensus on the diagnostic criteria and treatment strategies due to lack of large samples or prospective clinical trials. In order to improve recognition and diagnosis, and provide guidance regarding the treatment of M-HLH, the Study Group in HLH Subtypes of the Histiocyte Society has developed consensus recommendations for the diagnosis and management of M-HLH in 2015. In the present article, we summarized and discussed some updated understandings in M-HLH.

Adult cancer-related hemophagocytic lymphohistiocytosis - a challenging diagnosis: a case report

BACKGROUND

Adult hemophagocytic lymphohistiocytosis is a secondary immunopathologic phenomenon, mainly secondary to malignancy, infection, or autoimmune disorders. The performance of diagnostic criteria, studied in the pediatric population, is yet to be validated in the adult population. Some of the criteria include cytopenias and organomegaly that are inherent features to malignant processes, thus making the diagnosis of hemophagocytic lymphohistiocytosis a challenge in patients with cancer.

CASE PRESENTATION

We describe the case of a 54-year-old white man with history of metastatic maxillary sinus adenoid cystic carcinoma who had severe liver injury and cytopenias with progressive clinical deterioration. We performed an evaluation, by flow cytometry, of the expression of surface markers in his natural killer cells that revealed remarkable abnormalities. His syndrome eventually fulfilled criteria for hemophagocytic lymphohistiocytosis and he received therapy with steroids with interval clinical improvement. Unfortunately, he refused further cytotoxic treatment and died 2 weeks later.

CONCLUSIONS

The conventional criteria for the diagnosis of hemophagocytic lymphohistiocytosis are suboptimal for adult patients with cancer resulting in delays in diagnosis and timely initiation of treatment. The diagnostic criteria have to be re-evaluated in patients with cancer; novel, easily available, and accurate diagnostic methods are needed.