Infection- and malignancy-associated hemophagocytic syndromes. Secondary hemophagocytic lymphohistiocytosis

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.

Hemophagocytic Lymphohistiocytosis With Obstructive Jaundice as a Rare Presentation of Disseminated Tuberculosis in an Adult

Tuberculosis (TB) is a disease of global concern due to its varying clinical presentations and outcomes. Hemophagocytic lymphohistiocytosis (HLH) syndrome, along with obstructive jaundice, is one of the rarest presentations of tuberculosis involving immune activation and has a very high mortality rate. Thus, on-time diagnosis becomes crucial for the management of the disease. Prompt treatment with anti-tubercular therapy (ATT) can limit the morbidity and mortality associated with it. We report the case of a 28-year-old male who presented with fever, yellowish discoloration of the skin, features of bicytopenia, jaundice with hepatosplenomegaly, and ascites. The liver function test (LFT) was suggestive of obstructive jaundice. TB was confirmed on the analysis of lymph node aspirates, and the contrast-enhanced computed tomography (CECT) of the thorax and abdomen was suggestive of disseminated tuberculosis. Upon investigation, the criteria for HLH were fulfilled. Bone marrow aspiration smears revealed multiple hemophagocytic histiocytes in the background of a hypercellular marrow, erythroid hyperplasia, and myeloid-to-erythroid ratio of 1:1. Thus, a diagnosis of disseminated TB with HLH and obstructive jaundice was established. A modified ATT regimen was started, keeping in mind the deranged LFT of the patient, but no immunosuppressive therapy was initiated as it could make the TB worse. This case demonstrates the fact that in cases of hemophagocytic syndrome with tuberculosis as an underlying cause, just starting ATT without immunosuppression could be rewarding and lifesaving.

Presentations and outcomes of familial hemophagocytic lymphohistiocytosis in the pediatric intensive care units (PICUs)

Objectives

We aimed to describe Familial Hemophagocytic Lymphohistiocytosis (F-HLH) patients' clinical features, intensive care courses, and outcomes.

Methods

Multi-center retrospective cohort study of pediatric patients diagnosed with F-HLH from 2015 to 2020 in five tertiary centers in Saudi Arabia. Patients were classified as F-HLH based on their genetic confirmation of known mutation or on their clinical criteria, which include a constellation of abnormalities, early disease onset, recurrent HLH in the absence of other causes, or a family history of HLH.

Results

Fifty-eight patients (28 male, 30 female), with a mean age of 21.0 ± 33.9 months, were included. The most common principal diagnosis was hematological or immune dysfunction (39.7%), followed by cardiovascular dysfunction in 13 (22.4%) patients. Fever was the most common clinical presentation in 27.6%, followed by convulsions (13.8%) and bleeding (13.8%). There were 20 patients (34.5%) who had splenomegaly, and more than 70% of patients had hyperferritinemia >500 mg/dl, hypertriglyceridemia >150 mg/dl and hemophagocytosis in bone marrow biopsy. Compared to deceased patients 18 (31%), survivors had significantly lower PT (p = 041), bilirubin level of <34.2 mmol/L (p = 0.042), higher serum triglyceride level (p = 0.036), and lesser bleeding within the initial 6 h of admission (p = 0.004). Risk factors for mortality included requirements of higher levels of hemodynamic (61.1% vs. 17.5%, p = 0.001) and respiratory (88.9% vs. 37.5%, p < 0.001) support, and positive fungal cultures (p = 0.046).

Conclusions

Familial HLH still represents a challenge in the pediatric critical care setting. Earlier diagnosis and prompt initiation of appropriate treatment could improve F-HLH survival.

Successful use of rituximab for refractory hemophagocytic lymphohistiocytosis in a melanoma patient treated with targeted therapy

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening disease characterized by aberrant immune hyperactivation of T CD8 lymphocytes and macrophages driven by cytokine dysfunction. We report a 64-year-old man, with advanced BRAF-mutant melanoma treated by combined targeted therapies who had a recalcitrant and cortico-dependent Epstein-Barr virus (EBV)-induced HLH. One rituximab cycle led to a rapid and prolonged HLH remission which allowed to switch the targeted therapy for immunotherapy rituximab thus makes it possible to limit the use of corticosteroids, which limits the effectiveness of immunotherapy. The patient finally died of a cerebral tumoral progression 2 years later. Despite secondary hypogammaglobulinemia, we did not observe any severe infections during this period. This case suggests that rituximab can be a valuable option for EBV-induced HLH to avoid the T-suppressive effects of high-dose of corticosteroids in immunotherapy-treated patients.

L-DEP regimen is effective as an initial therapy for adult EBV-HLH

We performed a single-center, prospective trial to investigate the efficacy of PEG- asparaginase combined with liposomal doxorubicin, etoposide, and methylprednisolone (L-DEP) as an initial therapy for Epstein-Barr virus driven hemophagocytic lymphohistiocytosis (EBV-HLH). None of the patients received any chemotherapy after the diagnosis of EBV-HLH between September 2019 and September 2021. The efficacy was evaluated 2 weeks and 4 weeks after initiating L-DEP primary therapy. Forty-seven eligible patients with EBV-HLH were enrolled. The overall response rate (ORR) was 80.9% (38/47, 12 in clinical CR, 26 in clinical PR) at 2 weeks after the L-DEP regimen; at 4 weeks, the ORR was 75.6% (34/45, 21 in clinical CR, 13 in clinical PR). EBV-DNA loads in blood and plasma were significantly decreased 2 and 4 weeks after the L-DEP regimen (P < 0.001). Ferritin, soluble CD25 (sCD25), triglycerides (TGs), and ultrasonic spleen longitude, and thickness were all decreased significantly 2 and 4 weeks after the L-DEP regimen (P < 0.001). Thus, the L-DEP regimen is an effective initial therapy for EBV-HLH. However, the L-DEP regimen was poor in terms of long-term prognosis and that allo-HSCT should be received as soon as possible once a complete response is achieved.

TNFAIP3 mutation causing haploinsufficiency of A20 with a hemophagocytic lymphohistiocytosis phenotype: a report of two cases

BACKGROUND

A20 haploinsufficiency (HA20) is a newly introduced autosomal dominant autoinflammatory disorder, also known as Behcet's-like disease. Some of the most common symptoms of the disease are recurrent oral, genital, and/or gastrointestinal (GI) ulcers, episodic fever, musculoskeletal symptoms, cutaneous lesions, and recurrent infections. Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening condition of multi-organ failure due to excessive immune activation. HLH has been reported in a few HA20 patients. Herein, we report two children with the primary presentation of HLH, with a mutation in TNFAIP3, in favor of HA20.

CASE PRESENTATIONS

Our first patient was a 4-month-old boy who presented with fever, irritability, pallor, and hepatosplenomegaly. Pancytopenia, elevated ferritin, and decreased fibrinogen levels were found in laboratory evaluation. He was diagnosed with HLH and was treated with methylprednisolone and cyclosporine. Two years later, whole exome sequencing (WES) indicated a mutation in TNFAIP3 at NM_001270507: exon3: c.C386T, p.T129M, consistent with A20 haploinsufficiency. Etanercept, a TNF inhibitor, was prescribed, but the parents were reluctant to initiate the therapy. The patient passed away with the clinical picture of cerebral hemorrhage. The second patient was a 3-month-old boy who presented with a fever and hepatosplenomegaly. Laboratory evaluation found pancytopenia, hyperferritinemia, hypoalbuminemia, hypertriglyceridemia, and hypofibrinogenemia. With the establishment of the HLH diagnosis, he was treated with etoposide, dexamethasone, and cyclosporine, and recovered. WES results revealed a heterozygous de novo variant of TNFAIP3 (c. T824C in exon 6, 6q23.3) that leads to a proline to leucine amino acid change (p. L275P). He was treated with etanercept and has been symptom-free afterward.

CONCLUSIONS

This report is a hypothesis for developing of the HLH phenotype in the presence of TNFAIP3 mutation. Our results provide a new perspective on the role of TNFAIP3 mutation in HLH phenotypes, but more extensive studies are required to confirm these preliminary results.

Hemophagocytic Lymphohistiocytosis Associated With Hemolytic Uremic Syndrome in a Child: A Case Report and Systematic Literature Review

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening disorder resulting from excessive activation and nonmalignant proliferation of T-lymphocytes and macrophages. Hemolytic uremic syndrome (HUS) is a disease characterized by microangiopathic hemolytic anemia, thrombocytopenia, and acute renal failure. Reports pertaining to the association between HLH and HUS are rarely published; however, we report on a 4-year-old boy who was diagnosed with both conditions and treated successfully with high-dose steroid and intravenous immunoglobulin. Differentiating HUS from HLH can be challenging because of their clinical similarities. Therefore, prompt diagnosis and immunosuppressive treatment are essential and life-saving to these patients.

Diagnostic value of bone marrow cell morphology in visceral leishmaniasis-associated hemophagocytic syndrome: Two case reports

BACKGROUND

Visceral leishmaniasis related-hemophagocytic lymphohistiocytosis (VL-HLH) is a hemophagocytic syndrome caused by Leishmania infection. VL-HLH is rare, especially in nonendemic areas where the disease is severe, and mortality rates are high. The key to diagnosing VL-HLH is to find the pathogen; therefore, the Leishmania must be accurately identified for timely clinical treatment.

CASE SUMMARY

We retrospectively analyzed the clinical data, laboratory examination results, and bone marrow cell morphology of two children with VL-HLH diagnosed via bone marrow cell morphology at Kunming Children’s Hospital of Yunnan, China. Both cases suspected of having malignant tumors at other hospitals and who were unresponsive to treatment were transferred to Kunming Children’s Hospital. They are Han Chinese girls, one was 2 years old and the other one is 9 mo old. They had repeated fevers, pancytopenia, hepatosplenomegaly, hypertriglyceridemia, and hypofibrinogenemia over a long period and met the HLH-2004 criteria. Their HLH genetic test results were negative. Both children underwent chemotherapy as per the HLH-2004 chemotherapy regimen, but it was ineffective and accompanied by serious infections. We found Leishmania amastigotes in their bone marrow via morphological examination of their bone marrow cells, which showed hemophagocytic cells; thus, the children were diagnosed with VL-HLH. After being transferred to a specialty hospital for treatment, the condition was well-controlled.

CONCLUSION

Morphological examination of bone marrow cells plays an important role in diagnosing VL-HLH. When clinically diagnosing secondary HLH, VL-HLH should be considered in addition to common pathogens, especially in patients for whom HLH-2004 chemotherapy regimens are ineffective. For infants and young children, bone marrow cytology examinations should be performed several times and as early as possible to find the pathogens to reduce potential misdiagnoses.

Infection-Triggered Hyperinflammatory Syndromes in Children

An association between infectious diseases and macrophage activation syndrome (MAS) has been reported, yet the exact role of infection in MAS development is still unclear. Here, a retrospective analysis of the clinical records of patients with rheumatic diseases complicated with MAS who were treated in a pediatric tertiary care center between 2011 and 2020 was performed. Any infection documented within the 30 days preceding the onset of MAS was reported. Out of 125 children in follow-up for systemic rheumatic diseases, 12 developed MAS, with a total of 14 episodes. One patient experienced three episodes of MAS. Clinical and/or laboratory evidence of infection preceded the onset of MAS in 12 events. Clinical features, therapeutic strategies, and patient outcomes were described. The aim of this study was to evaluate the possible role of infection as a relevant trigger for MAS development in children with rheumatic conditions. The pathogenetic pathways involved in the cross-talk between uncontrolled inflammatory activity and the immune response to infection deserve further investigation.

Hemophagocytic Lymphohistiocytosis Following BNT162b2 mRNA COVID-19 Vaccination

Although serious adverse events have remained uncommon, cases of myocarditis induced by messenger RNA (mRNA) COVID-19 vaccines have been reported. Here, we presented a rare but potentially fatal disorder, hemophagocytic lymphohistiocytosis, in a 14-year-old previously healthy adolescent after BNT162b2 mRNA vaccination. The initial evaluation showed splenomegaly, pancytopenia, hyperferritinemia, and hypofibrinogenemia. Further examination revealed positive blood EBV DNA, and other infectious pathogen surveys were all negative. Hemophagocytosis was observed in the bone marrow aspiration and biopsy. HLH was confirmed and intravenous immunoglobulin (IVIG) and methylprednisolone pulse therapy were given. Venoarterial extracorporeal membrane oxygenation (VA-ECMO) was set up for cardiopulmonary support for 3 days due to profound hypotension. The patient was kept on oral prednisolone treatment for 28 days with the following gradual tapering. The hemogram and inflammatory biomarkers gradually returned to normal, and the patient was discharged. The fulminant presentation of HLH in our case could be the net result of both acute immunostimulation after COVID-19 vaccination and EBV infection. Our case suggests that the immune activation after COVID-19 vaccination is likely to interfere with the adequate immune response to certain infectious pathogens, resulting in a hyperinflammatory syndrome.

Elevated TNF-α Induces Thrombophagocytosis by Mononuclear Cells in ex vivo Whole-Blood Co-Culture with Dengue Virus

Background

Infection with dengue virus (DENV) causes hematological complications in dengue diseases characterized by thrombocytopenia accompanied by macrophage activation syndrome and hemophagocytosis in fatal patients.

Methods

In this study, we investigate the undefined mechanisms underlying the progression of thrombocytopenia caused by thrombophagocytosis based on an ex vivo whole-blood co-culture model of DENV infection for mimicking the acute febrile phase of infection.

Results

In this model, complete blood count test showed a decrease in monocytes (p < 0.01), but not neutrophils nor other white blood cells, accompanied by a low thrombocyte count (p < 0.01) in DENV infection with a positive correlation (r = 0.636, p < 0.05). Furthermore, DENV exposure caused significant thrombophagocytosis in mononuclear cells (p < 0.05). Abnormal production of tumor necrosis factor (TNF)-α was highly associated with induction of thrombophagocytosis (r = 0.758, p < 0.01), decreased monocytes (r = −0.758, p < 0.01), and decreased thrombocyte (r = −0.728, p < 0.01). Neutralizing TNF-α considerably (p < 0.05) reversed such DENV-induced effects and was further validated by immunostaining-based flow cytometry analysis on mononuclear CD14 positive monocytes. Exogenous administration of TNF-α effectively caused thrombophagocytosis accompanied by decreased monocytes and thrombocytes, probably causing monocyte activation.

Conclusion

These results demonstrate the potential pathogenesis of thrombocytopenia caused by TNF-α-induced thrombophagocytosis in monocytes during DENV infection.

Hemophagocytic lymphohistiocytosis associated with parvovirus B19-induced aplastic crisis in a hereditary spherocytosis patient: A case report and literature review

Hemophagocytic lymphohistiocytosis (HLH) is a syndrome of pathologic immune activation. It occurs because of severe inflammation due to uncontrolled proliferation of activated lymphocytes and histiocytes, characterized by the production of excessive levels of cytokines. Virus-associated HLH is a well-known entity, and parvovirus B19 is one of the common causes. Parvovirus B19 can also affect blood cell lineages. Therefore, HLH may be accompanied by several diseases such as cytopenia, aplastic anemia, and myelodysplastic syndrome. Herein, we report the case of a patient with hereditary spherocytosis who was diagnosed with parvovirus B19-induced HLH and aplastic crisis. A 7-year-old girl presented to our hospital with fever, pleural effusion, pancytopenia, hepatosplenomegaly, and hypotension. A bone marrow biopsy was performed under the suspicion of HLH, which revealed hemophagocytes. The diagnostic criteria for HLH were met, and prompt chemoimmunotherapy was initiated considering the clinically unstable situation. Her health improved rapidly after initiating treatment. Further study revealed that she had hereditary spherocytosis, and parvovirus B19 had caused aplastic crisis and HLH. The patient's clinical progress was excellent, and chemoimmunotherapy was reduced and discontinued at an early stage. This case shows that aplastic crisis and HLH can coexist with parvovirus B19 infection in patients with hereditary spherocytosis. Although the prognosis was good in this case of HLH caused by parvovirus B19, early detection and active treatment are essential.

Sepsis with liver dysfunction and coagulopathy predicts an inflammatory pattern of macrophage activation

Background

Interleukin-1 receptor antagonists can reduce mortality in septic shock patients with hepatobiliary dysfunction and disseminated intravascular coagulation (HBD + DIC), an organ failure pattern with inflammatory features consistent with macrophage activation. Identification of clinical phenotypes in sepsis may allow for improved care. We aim to describe the occurrence of HBD + DIC in a contemporary cohort of patients with sepsis and determine the association of this phenotype with known macrophage activation syndrome (MAS) biomarkers and mortality. We performed a retrospective nested case–control study in adult septic shock patients with concurrent HBD + DIC and an equal number of age-matched controls, with comparative analyses of all-cause mortality and circulating biomarkers between the groups. Multiple logistic regression explored the effect of HBD + DIC on mortality and the discriminatory power of the measured biomarkers for HBD + DIC and mortality.

Results

Six percent of septic shock patients (n = 82/1341) had HBD + DIC, which was an independent risk factor for 90-day mortality (OR = 3.1, 95% CI 1.4–7.5, p = 0.008). Relative to sepsis controls, the HBD + DIC cohort had increased levels of 21 of the 26 biomarkers related to macrophage activation (p < 0.05). This panel was predictive of both HBD + DIC (sensitivity = 82%, specificity = 84%) and mortality (sensitivity = 92%, specificity = 90%).

Conclusion

The HBD + DIC phenotype identified patients with high mortality and a molecular signature resembling that of MAS. These observations suggest trials of MAS-directed therapies are warranted.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40635-022-00433-y.

Haemophagocytic lymphohistiocytosis in a patient with familial Mediterranean fever and miliary tuberculosis: a case report

Haemophagocytic lymphohistiocytosis (HLH) is a lethal complication of several infections, especially viral origin. Mycobacterium tuberculosis infection can also lead to HLH, yet it is an uncommon trigger. Considering the role of increased cytokines in HLH, autoinflammatory conditions, such as familial Mediterranean fever (FMF), might contribute to its development. Nevertheless, the possible relationship between FMF and HLH has been suggested only in some case reports. We present a case of FMF who admitted to the hospital with consitutional symptoms and chest pain regarding to recurrent pericarditis. On a blood test, pancytopenia and elevated acute phase reactants were seen. Fluorine-18 fluorodeoxyglucose (FDG) positron emission tomography/computed tomography demonstrated positive FDG uptake sites on both the right and left surrenal glands, the visceral layer of pericard, and reactive lymphadenomegalies at multiple mediastinal regions. Bone marrow biopsy revealed haemophagocytosis. Methylprednisolone treatment was initiated. Despite immunosuppressive treatment, clinical and biochemical parameters deteriorated; thus, a thorax computed tomography was executed. Findings were consistent with miliary tuberculosis infection. M. tuberculosis was detected in blood culture and bronchoalveolar lavage culture material. Also, bone marrow and surrenal biopsy material revealed necrotising caseating granuloma.

Digenic Inheritance: Evidence and Gaps in Hemophagocytic Lymphohistiocytosis

Hemophagocytic lymphohistiocytosis (HLH) is a hyperinflammatory disorder characterized by the inability to properly terminate an immune response. Familial HLH (FHLH) and related immune dysregulation syndromes are associated with mutations in the genes PRF1, UNC13D, STX11, STXBP2, LYST, AP3B1, and RAB27A, all of which are required for the assembly, exocytosis, and function of cytotoxic granules within CD8+ T cells and natural killer (NK) cells. Loss-of-function mutations in these genes render the cytotoxicity pathway ineffective, thereby failing to eradicate immune stimuli, such as infectious pathogens or malignant cells. The resulting persistent immune system stimulation drives hypercytokinemia, ultimately leading to severe tissue inflammation and end-organ damage. Traditionally, a diagnosis of FHLH requires the identification of biallelic loss-of-function mutations in one of these degranulation pathway genes. However, this narrow definition fails to encompass patients with other genetic mechanisms underlying degranulation pathway dysfunction. In particular, mounting clinical evidence supports a potential digenic mode of inheritance of FHLH in which single loss-of-function mutations in two different degranulation pathway genes cooperate to impair pathway activity. Here, we review the functions of the FHLH-associated genes within the degranulation pathway and summarize clinical evidence supporting a model in which cumulative defects along this mechanistic pathway may underlie HLH.

Hemophagocytic Lymphohistiocytosis Induced by Epstein-Barr Virus Infection and Newly Diagnosed Hodgkin Lymphoma

Hemophagocytic lymphohistiocytosis (HLH) is a rare, but life-threatening disorder of pathologic immune system activation which results in a hyperinflammatory state. Previous studies have suggested that hematologic malignancies are often inciting factors for HLH and portend a poorer prognosis. However, the substantial overlap between features of hematologic malignancies and HLH makes recognition and prompt diagnosis of HLH a complex and difficult task. We present a case of a young male who presented with acute dyspnea on exertion, unintentional weight loss, and fatigue. He was found to have pancytopenia, fever, splenomegaly, and Epstein-Barr viremia and was subsequently diagnosed with nodular sclerosing Hodgkin lymphoma. Five of eight 2004-HLH criteria were met and the patient was started on intravenous dexamethasone (10 mg/m² daily), acyclovir, and AAVD (brentuximab, doxorubicin, vinblastine, dacarbazine) chemotherapy protocol with improvement in his symptoms and laboratory findings.

[Clinical prognostic analysis of 124 adult patients with hemophagocytic lymphohistiocytosis: a multicenter retrospective study of the Huaihai Lymphoma Working Group]

Objective: Factors influencing the prognosis of hemophagocytic lymphohistiocytosis (HLH) in adults were analyzed based on multicentric data. Methods: Clinical data of 124 adult patients with HLH diagnosed in eight medical centers in the Huaihai Lymphoma Working Group from March 2014 to July 2020 were collected. The optimal truncation value of continuous variables was obtained based on the Maxstat algorithm, X-Tile software, and restricted cubic spline. Cox proportional risk regression model was used to construct the adult HLH risk prediction model, and the visualization of the model was realized through the histogram. The bootstrap resampling method was used to verify the model, C-index and calibration curve was used to verify the histogram, and the prediction accuracy was checked. Kaplan-Meier analysis was used to calculate the survival rate and draw the survival curve. Furthermore, the differences between groups were tested by log-rank. Results: The median age of the 124 patients was 55 (18-84) years, including 61 (49.19%) males. The most common etiology was infection. Serum ferritin increased in 110 cases (88.71%) , hepatosplenomegaly in 57 cases (45.97%) . Of the 124 patients, 77 (62.10%) died, and the median survival time of the patients was 7.07 months. Univariate results showed that the prognosis of adult HLH was influenced by sex, age, fibrinogen, serum creatinine, alanine aminotransferase, and albumin (P<0.05) . The results of multivariate analysis showed that gender, platelet, albumin, alanine aminotransferase, and treatment regimens were independent influencing factors for prognosis. Based on the above five risk factors, the prediction model of the histogram was established, and the C-index of the model was 0.739. Finally, the calibration chart showed good consistency between the observed and predicted values of HLH. Conclusion: The prognosis of the adult hemophagocytic syndrome is influenced by many factors. Gender, platelet, albumin, alanine aminotransferase, and treatment regimens are independent risk factors. Therefore, the established histogram provides a visual tool for clinicians to evaluate the prognosis of adult HLH.

Pediatric hemophagocytic lymphohistiocytosis: A rarely diagnosed entity in a developing country

BACKGROUND

Hemophagocytic lymphohistiocytosis (HLH) is an exaggerated inflammatory reaction secondary to a host's inadequate immune response causing a self-perpetuating loop of altered regulation. Signs and symptoms of HLH are compatible with other common diseases and are nonspecific. Underdiagnosis makes it difficult to estimate the real incidence of HLH, especially in developing countries.

METHODS

Retrospective, descriptive study of pediatric patients admitted to a high-complexity institution in Cali, Colombia between 2012 and 2019 with HLH diagnosis. Medical history review to complete an electronic database and a secondary, descriptive analysis was carried out. The study was approved by the Institutional Ethics Committee.

RESULTS

Twenty-one patients were included. 52.4 % of the population was male with a median age of 9.3 years [IQR (3.0-13.7 years)]. More than half of patients (66.6 %) had viral disease at diagnosis, the most frequent being Epstein-Barr Virus (EBV) (52.3 %) and dengue (14.3 %). Three patients had confirmed gene mutations (G6PC3, XIAP, and UNC13D). 95 % of the patients were treated with the HLH 2004 protocol, half of them received incomplete protocol with intravenous immunoglobulin (IVIG) and/or systemic steroids, while the other half received the complete protocol including etoposide and cyclosporine. More than three-fourths (76.2 %) required admission to an ICU with a median stay of 14 days [IQR (11-37 days)] and a median hospital stay of 30 days [IQR (18-93 days)]. 14.3 % (n = 3) of patients died.

CONCLUSIONS

HLH is a complex disease that requires multidisciplinary management with secondary HLH due to EBV infection being a common cause. There is increasing awareness of HLH diagnosis in developing countries such as Colombia which can offer earlier treatment options and better outcomes.

Fever, cough and gastrointestinal symptoms in a pregnant woman

Despite distinct diagnostic criteria, several gastrointestinal pathologies can masquerade haemophagocytic lymphohistiocytosis (HLH) during the peripartum period. Acute fatty liver of pregnancy, HELLP (haemolysis, elevated liver enzymes and low platelets) syndrome, miliary tuberculosis, visceral leishmaniasis, abdominal surgical emergencies, haemolytic anaemias and haematological malignancies may have clinical and laboratory presentation similar to that of HLH. In this report, we present the case of a 26-year-old woman with 38-weeks' gestation and abdominal pain, vomiting, intermittent fever and non-productive cough for 1-2 months. A thorough investigation suggested HLH and the patient was successfully treated with corticosteroids. This patient demonstrates the importance of a focused investigation strategy and timely management to prevent mortality and morbidity to both the mother and fetus in this rare and fatal disease.

Genetic and clinical characteristics of pediatric patients with familial hemophagocytic lymphohistiocytosis

Background

Our study was designed to investigate the frequencies and distributions of familial hemophagocytic lymphohistiocytosis (FHL) associated genes in Saudi patients.

Methods

FHL associated gene screening was performed on 87 Saudi patients who were diagnosed with hemophagocytic lymphohistiocytosis (HLH) between 1995 and 2014. The clinical and biochemical profiles were also retrospectively captured and analyzed.

Results

Homozygous mutations and mono-allelic variants were identified in 66 (75.9%) and 3 (3.5%) of the study participants, respectively. STXBP2 was the most frequently mutated gene (36% of patients) and mutations in STXBP2 and STX11 accounted for 58% of all FHL cases and demonstrated a specific geographical pattern. Patients in the FHL group presented at a significantly younger age than those belonging to the unknown-genetics group (median, 3.9 vs. 9.4 mo; P=0.005). The presenting clinical features were similar among the various genetic groups and the 5-year overall survival (OS) was 55.4% with a 5.6 year median follow-up. Patients with PRF1 mutations had a significantly poorer 5-year OS (21.4%, P=0.008) and patients undergoing hematopoietic stem cell transplant (72.4%) had a significantly better 5-year OS (66.5% vs. 0%, P=0.001).

Conclusion

Our study revealed the predominance of the STXBP2 mutations in Saudi patients with FHL. A genetic diagnosis was possible in 80% of the cohort and our data showed improved survival in FHL patients who underwent hematopoietic stem cell transplant.

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

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

Infection-associated Hemophagocytic Syndrome in Critically Ill Patients with COVID-19

Infection-associated hemophagocytic syndrome (IAHS), a severe complication of various infections, is potentially fatal. This study aims to determine whether IAHS occurs in critically ill patients with coronavirus disease 2019 (COVID-19). We conducted a retrospective observational study on 268 critically ill patients with COVID-19 between February 1st, 2020 and February 26th, 2020. Demographics, clinical characteristics, laboratory results, information on concurrent treatments and outcomes were collected. A diagnosis of secondary hemophagocytic lymphohistiocytosis (sHLH) was made when the patients had an HScore greater than 169. Histopathological examinations were performed to confirm the presence of hemophagocytosis. Of 268 critically ill patients with confirmed SARS-CoV-2 infection, 17 (6.3%) patients had an HScore greater than 169. All the 17 patients with sHLH died. The interval from the onset of symptom of COVID-19 to the time of a diagnosis of sHLH made was 19 days and the interval from the diagnosis of sHLH to death was 4 days. Ten (59%) patients were infected with only SARS-CoV-2. Hemophagocytosis in the spleen and the liver, as well as lymphocyte infiltration in the liver on histopathological examinations, was found in 3 sHLH autopsy patients. Mortality in sHLH patients with COVID-19 is high. And SARS-CoV-2 is a potential trigger for sHLH. Prompt recognition of IAHS in critically ill patients with COVID-19 could be beneficial for improving clinical outcomes.

SARS-CoV-2 infection in an infant with non-respiratory manifestations: a case report

Background

Coronavirus disease (COVID-19) presents in children usually with less severe manifestations than in adults. Although fever and cough were reported as the most common symptoms, children can have non-specific symptoms. We describe an infant with aplastic anemia as the main manifestation.

Case presentation

We describe a case of SARS-CoV-2 infection in an infant without any respiratory symptoms or signs while manifesting principally with pallor and purpura. Pancytopenia with reticulocytopenia was the predominant feature in the initial laboratory investigations, pointing to aplastic anemia. Chest computed tomography surprisingly showed typical findings suggestive of SARS-CoV-2 infection. Infection was later confirmed by positive real-time reverse transcription polymerase chain reaction assay (RT-PCR) for SARS-CoV-2.

Conclusions

Infants with COVID-19 can have non-specific manifestations and a high index of suspicion should be kept in mind especially in regions with a high incidence of the disease. Chest computed tomography (CT) and testing for SARS-CoV-2 infection by RT-PCR may be considered even in the absence of respiratory manifestations.

Prognosis predicting value of semiquantitative parameters of visceral adipose tissue and subcutaneous adipose tissue of 18F-FDG PET/CT in newly diagnosed secondary hemophagocytic lymphohistiocytosis

PURPOSE

The purpose of this study was to investigate the prognosis predicting value of visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) of ¹⁸F-FDG PET/CT, and clinical inflammatory cytokines in newly diagnosed secondary hemophagocytic lymphohistiocytosis (SHLH).

METHODS

We retrospectively collected 58 patients with newly diagnosed SHLH from August 2016 to July 2019 in our hospital. All patients were followed up between 6 and 24 months. First, a comprehensive comparison of the general data between the death and the survival group was performed. Clinical lab indexes included were recorded and analyzed retrospectively. Second, the correlation between ¹⁸F-FDG PET/CT semiquantitative metabolic parameters of VAT, SAT and inflammatory cytokines was performed. 3D slicer software was used to get SUV and volume of VAT and SAT from ¹⁸F-FDG PET/CT. Third, overall survival (OS) analysis was performed. Finally, the prognosis predicting model was built based on risk factors to stratify SHLH patients.

RESULTS

There was significant difference in WBC, PLT, FBG, IL-10, PCR tests of EBV-DNA loads, SCD25 between the death group and the survival group. There was significant correlation between SAT coefficient variance (CV) and CRP, the mean standardized uptake value (SUVmean) of SAT (SAT SUVmean) and TG, SAT SUVmean and ESR. In univariate analysis with Cox regression analysis, SUVmean of VAT (VAT SUVmean), SAT Volume, SUVmean of SAT, CV of SAT (SAT HU CV), plasma EBV-DNA, WBC, PLT, FBG showed significance with OS. In multivariate Cox regression analysis, SAT Volume, SUVmean of SAT, plasma EBV-DNA, were independent prognostic factors for OS.

CONCLUSIONS

For newly diagnosed SHLH, SAT Volume, SUVmean of SAT, plasma EBV-DNA had significant relationship with poor prognosis. They were important independent predictors for overall survival for newly diagnosed SHLH.

Hemophagocytic Lymphohistiocytosis in a PICU of a Developing Economy: Clinical Profile, Intensive Care Needs, Outcome, and Predictors of Mortality

OBJECTIVES

To describe the clinical profile, intensive care needs, outcome, and predictors of mortality in critically ill children with hemophagocytic lymphohistiocytosis.

DESIGN

Retrospective case series.

SETTING

PICU of a tertiary care teaching hospital in North India.

PATIENTS

Children 2 months to 12 years old with the diagnosis of hemophagocytic lymphohistiocytosis admitted to PICU from January 2012 to April 2019 (7¼ yr).

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Sixty-two children with hemophagocytic lymphohistiocytosis (60 secondary and two primary) were enrolled. The median (interquartile range) age of the study group was 82 months (50.5-124 mo). The median (interquartile range) Pediatric Risk of Mortality III score was 16 (10-23). Majority of hemophagocytic lymphohistiocytosis was infection-associated (n = 51; 82.3%). Among these, scrub typhus accounted for 29% of cases (n = 18), dengue 17.7% (n = 11), bacterial sepsis 14.5% (n = 9), enteric fever 6.5% (n = 4), and other infections 14.5% (n = 9). Systemic-onset juvenile idiopathic arthritis accounted for 9.7% of cases (n = 6) and malignancy for 4.8% patients (n = 3). Majority of cases were treated with steroids (77.4%) and IV immunoglobulin (25.8%). Various complications noted were shock (71%), acute kidney injury (66.1%), acute respiratory distress syndrome (41.9%), disseminated intravascular coagulation (54.8%), CNS dysfunction (54.8%), multiple organ dysfunction syndrome (82.3%), and healthcare-associated infections (14.5%). Intensive care needs for primary illness and/or hemophagocytic lymphohistiocytosis included mechanical ventilation (74.2%); packed RBC (72.3%), fresh frozen plasma (40.3%), and platelet (48.4%) transfusion; vasoactive drugs (71%); and renal replacement therapy (24.2%). The median duration of PICU stay was 5 days (2.5-9.5 d) and mortality was 59.7% (n = 37). On univariate analysis, nonsurvivors had higher Pediatric Risk of Mortality III score; higher proportion of shock, acute kidney injury, acute respiratory distress syndrome, disseminated intravascular coagulation, and multiple organ dysfunction syndrome; the need for blood and blood components, mechanical ventilation, vasoactive drugs, and renal replacement therapy; higher Vasoactive-Inotropic Score; and prolonged duration of mechanical ventilation compared with survivors.

CONCLUSIONS

Hemophagocytic lymphohistiocytosis in PICU is commonly secondary to tropical infections and associated with high mortality. Higher severity of illness; shock and multiple organ dysfunction syndrome; need for blood and blood products, mechanical ventilation, vasoactive drugs, and renal replacement therapy; higher Vasoactive-Inotropic Score; and prolonged mechanical ventilation predicted death. Treatment of underlying infection and a less intense immunosuppressive therapy (steroids ± IV immunoglobulin) are suggested options. A high index of suspicion for complicating hemophagocytic lymphohistiocytosis is required in children with prolonged fever, cytopenias, organomegaly, and organ dysfunction not responding to conventional treatment.

IL-18 and infections: Is there a role for targeted therapies?

Interleukin (IL)-18 is a pro-inflammatory cytokine belonging to the IL-1 family, first identified for its interferon-γ-inducing properties. IL-18 regulates both T helper (Th) 1 and Th2 responses. It acts synergistically with IL-12 in the Th1 paradigm, whereas with IL-2 and without IL-12 it can induce Th2 cytokine production from cluster of differentation (CD)4⁺ T cells, natural killer (NK cells, NKT cells, as well as from Th1 cells. IL-18 also plays a role in the hemophagocytic lymphohistiocytosis, a life-threatening condition characterized by a cytokine storm that can be secondary to infections. IL-18-mediated inflammation was largely studied in animal models of bacterial, viral, parasitic, and fungal infections. These studies highlight the contribution of either IL-18 overproduction by the host or overresponsiveness of the host to IL-18 causing an exaggerated inflammatory burden and leading to tissue injury. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is responsible for the coronavirus disease 2019 (COVID-19). The damage in the later phase of the disease appears to be driven by a cytokine storm, including interleukin IL-1 family members and secondary cytokines like IL-6. IL-18 may participate in this hyperinflammation, as it was previously found to be able to cause injury in the lung tissue of infected animals. IL-18 blockade has become an appealing therapeutic target and has been tested in some IL-18-mediated rheumatic diseases and infantile-onset macrophage activation syndrome. Given its role in regulating the immune response to infections, IL-18 blockade might represent a therapeutic option for COVID-19, although further studies are warranted to investigate more in detail the exact role of IL-18 in SARS-CoV-2 infection.

Hemophagocytic Lymphohistiocytosis in Children

OBJECTIVE

To study the profile of children with Hemophagocytic Lymphohistiocytosis (HLH) in a tertiary care hospital for children.

METHODS

A retrospective analysis of case records of 52 children diagnossed with HLH was performed.

RESULTS

Of the 52 children 13% (n = 7) had Familial HLH and 87% (n = 45) had secondary HLH (sHLH). Common manifestations were fever (100%), organomegaly (87%), respiratory distress (54%), neurological symptoms (31%) and skin rashes (26.2%). Anemia and thrombocytopenia were present in 51% and 73% respectively. Hyperferritinemia was present in 96% and hypofibrinogenemia in 42% and high lactate dehydrogenase (LDH) in 91%. Bone marrow examination showed hemophagocytosis in 80%. Most common etiology among infections was viral infections (67%), of which Dengue was the most common (52%). Among children with sHLH 51% received supportive care only. Thirty-seven percent (n = 17) received intravenous (IV) immunoglobulin and steroids. Of these 77% (n = 35) recovered completely. Children with familial HLH were initiated on HLH 2004 protocol but all of them expired due to disease progression.

CONCLUSIONS

Identifying HLH early and managing it, poses a significant challenge. Prompt recognition and initiation of immunosuppressive therapy is extremely important for the better outcome; hence high clinical suspicion and structured work up including immunological, and genetic studies is required. It may be difficult to differentiate primary and secondary HLH in many instances unless genetic analysis is done. Identification of familial HLH is necessary for early referral to Hematopoietic Stem Cell Transplantation (HSCT). Hence screening for primary HLH needs to be considered in all children with HLH.

A case of pediatric visceral leishmaniasis-related hemophagocytic lymphohistiocytosis diagnosed by mNGS

•

Atypical clinical features make it hard to identify VL in HLH in non-epidemic area.

•

VL is difficult to diagnose when traditional tests are ineffective, while mNGS is.

•

mNGS can be used as a detection method of HLH in children caused by rare pathogens.

Background

Visceral leishmaniasis-related hemophagocytic lymphohistiocytosis (VL-HLH) is a secondary hemophagocytic syndrome, which can be life-threatening, caused by leishmania and transmitted by infected sandflies. Rapid and accurate identification of leishmania is crucial for clinical strategies.

Case report

Here, we report an infantile infection in a non-epidemic area of China. The infant was a 9.5-month-old girl with fever, pancytopenia and hepatosplenomegaly, which meet the HLH-2004 standard, and the negative gene results exclude congenital HLH. However, chemotherapy is ineffective and is accompanied by severe infection. Fortunately, she is diagnosed with VL-HLH (visceral leishmaniasis-related hemophagocytic lymphohistiocytosis), as leishmania is detected by next-generation meta-genome sequencing (mNGS) and quickly relieved after treatment with libosomal amphotericin B (L-AMB).

Conclusion

mNGS can detect leishmania in pediatric HLH, and should be performed as a new detection for VL-HLH, particularly for infants, who may not respond to HLH-2004 regimen.

Hemophagocytic lymphohistiocytosis: An update on pathogenesis, diagnosis, and therapy

Hemophagocytic lymphohistiocytosis (HLH) is a rare, life-threatening state of immune hyperactivation that arises in the setting of genetic mutations and infectious, inflammatory, or neoplastic triggers. Sustained, aberrant activation of cytotoxic CD8⁺ T cells and resultant inflammatory cytokine release are core pathogenic mechanisms. Key clinical features include high persistent fever, hepatosplenomegaly, blood cytopenia, elevated aminotransferase and ferritin levels, and coagulopathy. HLH is likely under-recognized, and mortality remains high, especially in adults; thus, prompt diagnosis and treatment are essential. Familial forms of HLH are currently treated with chemotherapy as a bridge to hematopoietic stem cell transplantation. HLH occurring in rheumatic disease (macrophage activation syndrome) is treated with glucocorticoids, IL-1 blockade, or cyclosporine A. In other forms of HLH, addressing the underlying trigger is essential. There remains a pressing need for more sensitive, context-specific diagnostic tools. Safer, more effective therapies will arise with improved understanding of the cellular and molecular mechanisms of HLH.

Proinflammatory Cytokine Secretion in a Patient With Recurrent Neuroblastoma Related to the Onset of Malignancy-associated Hemophagocytic Lymphohistiocytosis

The onset of malignancy-associated hemophagocytic lymphohistiocytosis (M-HLH) may be associated with the secretion of proinflammatory cytokines from malignant cells. We here report a patient with recurrent neuroblastoma who developed hemophagocytic lymphohistiocytosis after surgery for brain metastases and relapsed after chemotherapy. The neuroblastoma cells in the recurrent tumor were positive for tumor necrosis factor-α and interleukin-6, whereas the primary site was negative. The secretion of proinflammatory cytokines from neuroblastoma cells may have been related to the pathogenesis of M-HLH in our patients. We should pay attention to possible development of M-HLH when treating advanced neuroblastoma.

Clinical outcomes of adults with hemophagocytic lymphohistiocytosis treated with the HLH-04 protocol: a retrospective analysis

Hemophagocytic lymphohistiocytosis (HLH) is a rare syndrome of pathologic immune activation in children that is increasingly being recognized in adults. Efficacy data for the HLH-04 protocol in adults is lacking. This study retrospectively analyzed 31 adult patients, median age 46 years, who received HLH-04 from 1/1/2004 to 5/1/2018. HLH etiology included malignancy (n = 9), autoimmune (n = 8), infection (n = 8), and idiopathic (n = 6). Eighteen patients were evaluable for response at week 4 with 7 having no response, 11 reaching partial response, and 0 reaching complete response (CR). Six patients eventually achieved CR at a median 195 days. The 1-year overall survival (OS) was 35% and median OS was 3.2 months. Univariate analysis showed shorter survival for hemoglobin <9 g/dL (HR 4.29, p = 0.003), platelets <100 × 10⁹/L (HR 4.06, p = 0.027), ANC <1 × 10⁹/L (HR 5.24, p = 0.001), and total bilirubin >1.2 mg/dL (HR 3.30, p = 0.022). Outcomes of adults treated with HLH-04 remain dismal and newer treatment modalities are needed.

Coagulation Disorders in Hemophagocytic Lymphohistiocytosis/Macrophage Activation Syndrome

Hemophagocytic lymphohistiocytosis (HLH) is a rare and severe condition that can lead patients to the intensive care unit. HLH diagnosis may be challenging, as it relies on sets of aspecific criteria. Several organ dysfunctions have been described during HLH, including hemostasis impairment found in more than half of the patients. The most frequently reported anomaly is a decrease in the fibrinogen level, which has been associated with higher mortality rates. Coagulation impairment study in patients with HLH represents an interesting field of research, as little is known about the mechanism leading to hypofibrinogenemia.

Clickable, acid labile immunosuppressive prodrugs forin vivotargeting

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Kawasaki Disease: Beyond IVIG and Aspirin

Kawasaki disease (KD) is a vasculitis syndrome of unknown etiology, affecting medium-sized vessels and occurring primarily in young children. It is a self-limited illness classically presenting with fever, conjunctivitis, mucocutaneous lesions, and cervical adenopathy. However, vasculitis of coronary arteries with aneurysm formation may occur, leading to morbidity and rarely mortality. Prompt diagnosis of KD is essential as early treatment with intravenous immune globulin (IVIG) decreases the occurrence and severity of coronary vasculitis. This article reviews the clinical characteristics of KD, laboratory assessment, echocardiogram findings, and recommended initial medical therapy. Complications of KD are discussed, including KD refractory to IVIG, the presence of shock or macrophage activation syndrome (MAS), and short/long-term cardiac sequelae. The medical management of these complications is reviewed. Although improved treatment of KD has resulted in a decrease of coronary artery vasculitis over the past 3 decades, KD remains the most common cause of acquired heart disease in children. [Pediatr Ann. 2019;48(10):e400-e405.].

Epstein-Barr virus (EBV) reactivation and therapeutic inhibitors

Epstein-Barr virus (EBV) is a ubiquitous human virus which infects almost all humans during their lifetime and following the acute phase, persists for the remainder of the life of the individual. EBV infects B lymphocytes leading to their immortalisation, with persistence of the EBV genome as an episome. In the latent phase, EBV is prevented from reactivating through efficient cytotoxic cellular immunity. EBV reactivates (lytic phase) under conditions of psychological stress with consequent weakening of cellular immunity, and EBV reactivation has been shown to occur in a subset of individuals with each of a variety of cancers, autoimmune diseases, the autoimmune-like disease, chronic fatigue syndrome/myalgic encephalitis and under other circumstances such as being an inpatient in an intensive care unit. Chronic EBV reactivation is an important mechanism in the pathogenesis of many such diseases, yet is rarely tested for in immunocompetent individuals. This review summarises the pathogenesis of EBV infection, EBV reactivation and its role in disease, and methods which may be used to detect it. Known inhibitors of EBV reactivation and replication are discussed, including drugs licensed for treatment of other herpesviruses, licensed or experimental drugs for various other indications, compounds at an early stage of drug development and nutritional constituents such as vitamins and dietary supplements.

Disturbances in NK Cells in Various Types of Hemophagocytic Lymphohistiocytosis in a Population of Polish Children

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening disease associated with immune system hyperactivation and the appearance of serious systemic disturbances. The purpose of this study was an assessment of natural killer (NK) cell disturbances in a group of children with clinical signs of HLH. A total of 43 children with HLH and 17 healthy children were enrolled in the study. NK phenotyping, intracellular perforin staining, and cytotoxicity tests were performed by using the flow cytometry method. HLH patients were divided into 6 HLH types: 9% infection-related HLH; 7% malignancy-related HLH; 21% macrophage activating syndrome; 12% familial hemophagocytic lymphohistiocytosis; 2% X-linked lymphoproliferative syndrome; and 49% as HLH of unknown background. A positive correlation was observed between cytotoxicity and NK cells in children with HLH (P=0.01). In all HLH groups, the percentage of NK cells was significantly lower than in the control population. The spontaneous cytotoxicity was significantly lower in HLH patients. The results presented in this study indicate the importance of impaired function and the number of NK cells in the pathogenesis of HLH. Nonetheless, the background of disturbances seems to be different in various cases.

Miliary Tuberculosis-Related Acute Respiratory Distress Syndrome Complicated with Hemophagocytic Lymphohistiocytosis Syndrome

Acute respiratory distress syndrome (ARDS) and hemophagocytic lymphohistiocytosis (HLH) are accompanied with poor outcome and high mortality when miliary tuberculosis is a causative pathogen for both of them. A patient complicated with ARDS and HLH is unusual in critical care, and few case reports are present in PudMed. Besides, the relationship between HLH and ARDS is still unknown and has not been reviewed in the literature. In this report, we present the case of a 74-year-old Taiwanese woman suffering from pulmonary tuberculosis and miliary tuberculosis, and she developed ARDS and HLH on the 3rd day after admission. We arranged serial laboratory examination, various serum markers, bone marrow aspiration, and bronchoscopy with alveolar lavage for survey; we prescribed empirical antibiotics and antituberculosis medication soon after alveolar lavage showing positive acid-fast stain. She was extubated on hospital day 31 and discharged on hospital day 73. In conclusion, early diagnosis and intervention for underlying disease and intensive bundle care for multiorgan failure are crucial for both ARDS and HLH.

Hemophagocytic lymphohistiocytosis due to Streptococcus suis in a 12-year-old girl: A case report

RATIONALE

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening hyperinflammatory syndrome that can be caused by bacterial infection. Streptococcus suis (S. suis) is a zoonotic pathogen that can cause severe disease in both pigs and humans. We report the first-ever documented case of HLH secondary to S. suis infection.

PATIENT CONCERNS

A 12-year-old girl presented with fever, rash, hepatosplenomegaly, pancytopenia, and elevated levels of ferritin and soluble CD25. Bone marrow examination revealed hemophagocytosis. Blood culture was positive for S. suis.

DIAGNOSIS

A diagnosis of hemophagocytic syndrome due to S. suis was established.

INTERVENTIONS

We treated the patient with intravenous immunoglobulin, intravenous imipenem, and supportive care.

OUTCOMES

The patient eventually showed complete recovery.

LESSONS

Inflammatory response plays an important role in S. suis infection. Aberrant inflammatory response to S. suis infection may induce HLH. This case report illustrates that early definitive diagnosis and prompt treatment is a key imperative in patients with suspected S. suis infection.

Hemophagocytic Lymphohistiocytosis Secondary to Malignancy and Chemotherapy in Pediatric Patients: A Single-Institution Experience

Hemophagocytic lymphohistiocytosis (HLH) is an uncommon yet potentially devastating systemic disease, arising from uncontrolled activation of the immune system. While the primary form of this disease can be caused by genetic mutation(s), the secondary form may be triggered by infection and hematologic, malignant, and metabolic conditions. The diagnosis of HLH remains a clinical challenge due to nonspecific symptoms. Proper diagnosis is significantly more difficult among patients with acute leukemia who have received chemotherapy. The objective of this study is to describe three unique cases of secondary HLH, describe the specific treatment, and improve the awareness of this condition. Two patients with acute myeloid leukemia (AML) and one with acute lymphoblastic leukemia were diagnosed with HLH, having fulfilled the criteria as outlined in the HLH-2004 protocol. They then received HLH-specific treatment. Two patients passed – one from refractory HLH and one from primary disease (i.e., AML) – and one patient remains alive 22 months after her allogeneic bone marrow transplant. The diagnosis of HLH requires the presence of any five of the eight criteria. Due to its heterogeneous presentation, it remains imperative that treating clinicians remain cognizant about HLH so that prompt diagnosis may allow appropriate treatment.

Clinical characteristics of extranodal NK/T-cell lymphoma-associated hemophagocytic lymphohistiocytosis

Background

Extranodal natural killer (NK) / T cell lymphoma is a subtype of non-Hodgkin's lymphoma (NHL) that usually has an aggressive clinical course. It is the predominant trigger of lymphoma-associated hemophagocytic syndrome (LAHS), which is highly lethal and with extremely poor prognosis. This study is aiming to characterize the associated clinical features and prognostic factors of the disease.

Patients and methods

Twenty-eight patients with extranodal NK/T cell lymphoma associated hemophagocytic lymphohistiocytosis (HLH) were retrospectively analyzed. The clinical records were collected, and the associations between clinical or laboratory parameters and overall survival (OS) were assessed.

Results

The most frequently clinical characteristics were fever (96.4%), and splenomegaly (81.5%). Concerning the laboratory findings, the most common features were hyperferritinemia (91.7%), grade III/IV thrombocytopenia (64.3%), hypertriglyceridemia (48%), severe anemia (46.4%), hypofibrinogenemia (45%), and grade III/IV neutropenia (32.1%). The interval between the diagnosis of NK/T LAHS and death / last contact was between 4 to 701 days with the median interval of 15 days. We found that higher serum lactic dehydrogenase (LDH) at HLH, hypofibrinogenemia, and splenomegaly were significantly associated with worse survival (P=0.002, 0.003, 0.003). Furthermore, Eastern Cooperative Oncology Group (ECOG) score, extra-upper aerodigestive tract NK/T cell lymphoma (EUNKTL) and cutaneous involvement were risk factors of HLH.

Conclusion

Our data indicated that levels of LDH, fibrinogen, and presence of splenomegaly were prognostic factors of the disease. Higher ECOG scores, EUNKTL and cutaneous involvement were risk factors of NK/T LAHS. Additional independent, prospective clinical trials will be needed to explore optimal treatment.

Autoimmune-Associated Hemophagocytosis and Myelofibrosis in a Newly Diagnosed Lupus Patient: Case Report and Literature Review

Bone marrow abnormalities in SLE are now becoming increasingly recognized, suggesting that the bone marrow may also be an important site of target organ damage. In this study, we present a rare case of concurrent autoimmune hemophagocytic syndrome and autoimmune myelofibrosis, potentially life-threatening conditions, in a newly diagnosed SLE patient. We report a case of a 30-year-old Filipino woman who presented with a one-year history of fever, constitutional symptoms, exertional dyspnea, joint pains, and alopecia and physical examination findings of fever, facial flushing, cervical lymphadenopathies, and knee joint effusions. Laboratory workup revealed pancytopenia with leukoerythroblastosis, elevated ESR, increased serum levels of transaminases, elevated CRP and LDH, hyperferritinemia, hypertriglyceridemia, proteinuria, hepatomegaly, and positive antinuclear antibody. Bone marrow aspiration and trephine biopsy revealed hemophagocytosis and moderate myelofibrosis. The patient was diagnosed with SLE with concomitant autoimmune-associated hemophagocytic syndrome and autoimmune myelofibrosis. Treatment with high-dose corticosteroids led to dramatic clinical improvement with normalization of laboratory data and complete resolution of bone marrow hemophagocytosis and myelofibrosis. Hemophagocytosis and myelofibrosis, although uncommon, are possible initial manifestations of SLE and should be included in the differential diagnosis of cytopenias in SLE. Thorough clinical assessment and microscopic bone marrow examination and timely initiation of corticosteroid therapy are essential in the diagnosis and management of these potentially life-threatening conditions. This case emphasizes that the bone marrow is an important site of target organ damage in SLE, and evaluation of cytopenias in SLE should take this into consideration.

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.

Are the 2016 EULAR/ACR/PRINTO classification criteria for macrophage activation syndrome applicable to patients with adult-onset Still's disease?

The objectives of this study are to determine whether the 2016 European League Against Rheumatism/American College of Rheumatology/Paediatric Rheumatology International Trials Organization classification criteria for macrophage activation syndrome (MAS) complicating systemic juvenile idiopathic arthritis (SJIA) can be used to identify MAS in patients with adult-onset Still's disease (AOSD). Using laboratory data from 76 AOSD patients with and without MAS, we analyzed the ability of the collective and individual constitutive elements of the 2016 MAS in SJIA criteria and additional laboratory measures to discriminate between AOSD patients with (n = 16) and without (n = 60) MAS. Cutoff values to determine the sensitivity, specificity, and predictive values were calculated from receiver operating characteristic curves, and modified classification criteria for MAS in AOSD were evaluated. The 2016 MAS in SJIA classification criteria had an overall sensitivity of 100%, specificity of 70.0%, positive predictive value of 47.1%, and negative predictive value of 100% to discriminate between AOSD patients with and without MAS based on laboratory data. Among the individual criteria, the sensitivity of triglycerides (46.7%) and the specificity of ferritin (15.0%) for MAS in AOSD were particularly low. The sensitivity and specificity for classifying MAS in AOSD patients were increased to 100 and 93%, respectively, by excluding triglycerides and changing the cutoff values for other criteria in the 2016 MAS in SJIA classification. The 2016 classification criteria for MAS in SJIA had higher sensitivity but lower specificity to identify MAS in AOSD patients compared with SJIA patients.

Unopposed IL-18 signaling leads to severe TLR9-induced macrophage activation syndrome in mice

The term macrophage activation syndrome (MAS) defines a severe, potentially fatal disorder characterized by overwhelming inflammation and multiorgan involvement. Interleukin-18 (IL-18) is a proinflammatory cytokine belonging to the IL-1 family, the activity of which is regulated by its endogenous inhibitor IL-18 binding protein (IL-18BP). Elevated IL-18 levels have been reported in patients with MAS. Herein, we show that on repeated toll-like receptor 9 (TLR9) stimulation with unmethylated cytosine guanine dinucleotide containing single-stranded DNA (CpG), IL-18BP^-/- mice display severe MAS manifestations, including increased weight loss, splenomegaly, anemia, thrombocytopenia, hyperferritinemia, and bone marrow hemophagocytosis as compared with wild-type mice. Serum-free IL-18 was detected in CpG-treated IL-18BP^-/- mice only. Levels of interferon-γ (IFN-γ) and of IFN-γ signature genes, such as the chemokine Cxcl9 or the transcription factor CIIta, were significantly increased in IL-18BP^-/- mice. Blocking IL-18 receptor signaling attenuated the severity of MAS and IFN-γ responses in IL-18BP^-/- mice. Blocking IFN-γ had comparable effects to IL-18 inhibition on most MAS manifestations. Our data indicate that endogenous IL-18BP exerts a protective role in CpG-induced MAS and that IL-18, which acts upstream of IFN-γ, is involved in the severity of MAS.

Hemophagocytic lymphohistiocytosis in an adult kidney transplant recipient successfully treated by plasmapheresis: A case report and review of the literature

RATIONALE

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening disease entity primarily described in children, but not less relevant in adults. It is characterized by a misdirected activation of the immune system, resulting in an uncontrolled cytokine release from macrophages and cytotoxic T-cells (CTLs). Primary HLH relies on a genetic predisposition, whereas secondary HLH develops in the context of infections, malignancies or autoimmune diseases. However, the awareness and therapeutic knowledge for HLH in adulthood is limited. Most therapy protocols are almost exclusively validated in pediatric cohorts and for primary HLH. Their transferability to adult individuals with mostly secondary HLH is doubtful. Especially the high liver and bone marrow toxicity of applied etoposide-based protocols is discussed controversially and connected to overwhelming infections and death.

PATIENT CONCERN

A 51-year old, male, kidney transplant recipient was admitted to our center suffering from diarrhea, fever, nausea, hyponatremia, kidney graft failure, disorientation, progressive hemodynamic instability, and multiorgan failure.

DIAGNOSES

Clinical and laboratory findings resembled those of a septic shock. Ferritin and soluble interleukin-2 receptor (sCD25) levels were disproportionally elevated. Only a mild hepatosplenomegaly was diagnosed in a CT scan. A T2-weighted, fluid-attenuated inversion recovery MRI showed marked, bilateral and periventricular white matter hyperintensities. The cerebrospinal fluid (CSF) analysis showed a moderately elevated protein content and cell count. There was no evidence of any bacterial, viral, or parasitic infection. The diagnosis of HLH was made.

INTERVENTIONS & OUTCOMES

The patient was successfully treated by a combined approach consisting of plasma exchange (PE), corticosteroids, anakinra, and cyclosporine (CsA).

LESSONS

HLH is an important differential diagnosis in critically ill patients. Its unspecific clinical picture complicates an early diagnosis and may be misclassified as sepsis. A combination of plasma exchange (PE), corticosteroids, anakinra, and cyclosporine (CsA) may be a promising and less toxic approach for HLH therapy in adults.