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

A predictive model for identifying secondary underlying diseases of hemophagocytic lymphohistiocytosis

Background

Secondary hemophagocytic lymphohistiocytosis (HLH) is a rare, life-threatening disease of immune hyperactivation that arises in the context of infectious, inflammatory, or neoplastic triggers. The aim of this study was to establish a predictive model for the timely differential diagnosis of the original disease resulting in HLH by validating clinical and laboratory findings to further improve the efficacy of therapeutics for HLH.

Methods

We retrospectively enrolled 175 secondary HLH patients in this study, including 92 patients with hematologic disease and 83 patients with rheumatic disease. The medical records of all identified patients were retrospectively reviewed and used to generate the predictive model. We also developed an early risk score using multivariate analysis weighted points proportional to the β regression coefficient values and calculated its sensitivity and specificity for the diagnosis of the original disease resulting in HLH.

Results

The multivariate logistic analysis revealed that lower levels of hemoglobin and platelets (PLT), lower levels of ferritin, splenomegaly and Epstein-Barr virus (EBV) positivity were associated with hematologic disease, but young age and female sex were associated with rheumatic disease. The risk factors for HLH secondary to rheumatic diseases were female sex [OR 4.434 (95% CI, 1.889-10.407), P =0.001], younger age [OR 6.773 (95% CI, 2.706-16.952), P<0.001], higher PLT level [OR 6.674 (95% CI, 2.838-15.694), P<0.001], higher ferritin level [OR 5.269 (95% CI, 1.995-13.920), P =0.001], and EBV negativity [OR 27.656 (95% CI, 4.499-169.996), P<0.001]. The risk score included assessments of female sex, age, PLT count, ferritin level and EBV negativity, which can be used to predict HLH secondary to rheumatic diseases with an AUC of 0.844 (95% CI, 0.836~0.932).

Conclusion

The established predictive model was designed to help clinicians diagnose the original disease resulting in secondary HLH during routine practice, which might be improve prognosis by enabling the timely treatment of the underlying disease.

Prognostic value of lipid profile in adult hemophagocytic lymphohistiocytosis

Background

Adult secondary hemophagocytic lymphohistiocytosis (sHLH) is a rare clinical syndrome with a high mortality rate. Currently, there are no feasible prognostic factors to clinically predict untreated sHLH patients' prognosis. Our objective was to characterize the lipid profile of adult sHLH patients and to determine the relationship with overall survival.

Methods

We retrospectively analyzed 247 patients with newly diagnosed sHLH from January 2017 to January 2022 according to the HLH-2004 criteria. Multivariate Cox regression analyses and restricted cubic splines were conducted to evaluate the prognostic value of the lipid profile.

Results

The median age of all patients was 52 years, and the commonest cause of sHLH in our cohort was malignancy. During a median follow-up of 88 (interquartile ranges, 22-490) days, 154 deaths occurred. The univariate analysis confirmed total cholesterol (TC) ≤ 3 mmol/L, triglycerides (TG) > 3.08 mmol/L, high-density lipoprotein cholesterol (HDL-c) ≤ 0.52 mmol/L, and low-density lipoprotein cholesterol (LDL-c) ≤ 2.17 mmol/L were associated with an inferior survival. In a multivariate model, HDL-c, hemoglobin, platelet, fibrinogen, and soluble interleukin-2 receptor were considered as independent factors. Additionally, the restricted cubic spline analyses indicated an inverse linear association between HDL-c and the risk of mortality in sHLH.

Conclusion

Lipid profiles, which were low-cost and readily available promising biomarkers, were strongly associated with the overall survival in adult sHLH patients.

Connective tissue disease with macrophage activation syndrome: A case report

RATIONALE

Macrophage activation syndrome (MAS), or secondary hemophagocytic lymphocytosis (sHLH), is a rare systemic inflammatory response syndrome that is fatal. Adult patients lack clear criteria for diagnosis and treatment, primarily derived from guidelines and protocols for treating family hemophagocytic lymphocytosis and systemic juvenile idiopathic arthritis (sJIA)-related MAS in children or from retrospective case reports. As a subtype of sHLH, MAS has a clinical presentation like sHLH, but treatment varies. Herein, we report the case of a 40-year-old female with MAS caused by a connective tissue disease.

PATIENT CONCERNS

The patient presented to the Rheumatology and Immunology Clinic with recurrent fever and rash, and MAS was confirmed after a series of examinations. The patient had no significant effect after treatment with JAK inhibitors, but after the use of the IL-6 inhibitor tocilizumab, the fever and rash were significantly reduced, and laboratory indicators returned to normal levels.

DIAGNOSIS

Considering the patient's condition and laboratory test results, we judged that the patient had connective tissue disease with MAS.

INTERVENTIONS

We gave sequential treatment of tocilizumab.

OUTCOMES

ALL indicators are mostly back to normal when the patient was monitored at the outpatient clinic.

LESSONS

MAS/HLH lacks clear criteria for diagnosis or treatment in adult patients and is extremely difficult to distinguish from bacterial sepsis or other systemic inflammatory response syndromes. Consequently, early diagnosis and treatment are indispensable for enhancing patient survival.

Hemophagocytic Lymphohistiocytosis Associated with Synergistic Defects of AP3B1 and ATM Genes: A Case Report and Literature Review

Hemophagocytic lymphohistiocytosis (HLH) is an overwhelming immune system activation that manifests as hyperinflammation and life-threatening multiple organ failure. However, the clinical manifestations of the systemic inflammatory response in sepsis and fulminant cytokine storm caused by HLH macrophage activation are very similar and difficult to distinguish. HLH triggered by two novel gene defects manifesting with multiorgan dysfunction syndrome (MODS) and distributive shock has not been reported. A 14-year-old male patient was hospitalized with a high fever, his condition deteriorated rapidly, accompanied by cytopenia, shock, and MODS, and he was subsequently transferred to our intensive care unit (ICU) for symptomatic and organ-supportive treatments. Laboratory indicators of cytopenia, hypofibrinogenemia, hypertriglyceridemia, hyperferritinemia, high soluble CD25, low natural killer (NK) cell cytotoxicity, and hemophagocytosis in the bone marrow confirmed the diagnosis of HLH. Molecular genetic analysis revealed that two novel heterozygous gene mutations in AP3B1 (c.3197 C > T) and ATM (c.8077 G > T) might have accounted for the onset. After treatment, the patient’s condition successfully improved. This case report demonstrates the timely determination of underlying triggers and critical care supports (supportive and etiological treatment) of HLH related to the improved outcome.

"A Dangerous Black Box:" Idiopathic Hemophagocytic Lymphohistiocytosis in Adult Patients-A Case Report and Review of the Literature

Hemophagocytic lymphohistiocytosis (HLH) is a rare potentially life-threatening condition characterized by aberrant inflammation that can be related to genetic or sporadic forms. In both forms, triggering factors may be involved. Early detection of the underlying cause is crucial for therapeutic decision, while early intervention might be associated with better outcomes. The largest descriptions in the literature on HLH refer to pediatric cases. Adolescents and adults may also be affected, but there is scarce evidence regarding their diagnosis and management. We describe here the case of a 68-year-old Swiss woman with HLH, in whom an extensive search for underlying causes was performed, but neither trigger nor pathogenic variant was found. An early intervention first with dexamethasone and later with cyclosporine was performed. The patient showed a favorable response and did not require further hospitalization; however, one year after diagnosis, it was not possible to suspend cyclosporine due to recurrence of laboratory inflammation signs by drug tapering. The occurrence of HLH idiopathic forms represents a challenge; failure to identify the underlying triggering cause generates uncertainty, endless diagnostic investigations, and consequently additional delays in the treatment. This manuscript addresses the difficulties on this issue.

Refractory systemic onset juvenile idiopathic arthritis: current challenges and future perspectives

Systemic juvenile idiopathic arthritis (SJIA) is a rare disease with distinct features not seen in other categories of juvenile idiopathic arthritis. In recent years, advances in the understanding of disease immunopathogenesis have led to improved targeted therapies with significant improvement in patient outcomes. Despite these advances, there remain subsets of SJIA with refractory disease and severe disease-associated complications. This review highlights existing options for treatment of refractory SJIA and explores potential future therapeutics for refractory disease.Key Points:Despite targeted Interleukin IL-1 and IL-6 inhibitors a subset of SJIA remains refractory to therapy. About 1 in 7 SJIA patients will be refractory to targeted IL-1 or IL-6 therapy.There is no current agreed upon definition for refractory SJIA and we propose in this review that refractory SJIA is presence of active systemic or arthritic features despite treatment with anti-IL-1 or anti-IL-6 therapy or disease requiring glucocorticoids for control beyond 6 months.SJIA disease associated complications include presence of associated macrophage activation syndrome (MAS), interstitial lung disease (ILD) or amyloidosis and management of each differs.Refractory SJIA treatment options currently include additional conventional synthetic disease modifying anti-rheumatic drugs (csDMARDS), biologic (bDMARDS), combination biologic therapy, targeted synthetic (tsDMARDS) or other immunomodulatory therapies.

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

Objectives

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

Methods

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

Results

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

Conclusion

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

Treatment-related hemophagocytic lymphohistiocytosis due to atezolizumab: a case report and review of the literature

Background

Immune checkpoint inhibitors avoid inhibition of T-cell responses, upregulating antitumor immune response. Moreover, a dysregulation with hyperactive immune response can be caused, some of them underdiagnosed. Hemophagocytic lymphohistiocytosis is a rare and often fatal syndrome of uncontrolled and ineffective hyperinflammatory response that triggers an inflammatory cascade that can lead in many cases to death.

Case presentation

We report the case of a 67-year-old Caucasian man with stage IV lung adenocarcinoma who developed hemophagocytic lymphohistiocytosis after initiation of atezolizumab, an antagonist of programmed death-ligand 1. Even with early diagnosis and proper treatment, death occurs in approximately half of all cases reported.

Conclusion

Key markers are needed to better identify patients at risk of developing severe immune-related adverse events. In addition to key markers, a higher degree of suspicion and early intervention are needed to improve outcomes in acquired hemophagocytic lymphohistiocytosis, especially with the increasingly and expanding use of immune activation.

Case report: Ruxolitinib as first-line therapy for secondary hemophagocytic lymphohistiocytosis in patients with AIDS

Background

Hemophagocytic lymphohistiocytosis (HLH) is a fatal immunological syndrome resulting from excessive production of inflammatory cytokines. The conventional therapies for HLH, which are based on cytotoxic agents, are not always efficacious and safe, especially in patients with severe immunodeficiency. Ruxolitinib, a strong inhibitor of Janus kinase (JAK) 1/2, has already been evaluated as salvage and first-line therapy for HLH. Despite its promising efficacy and tolerability in the treatment of secondary HLH, the efficacy and safety of ruxolitinib in HLH patients with HIV infection remain to be investigated.

Case presentation

Two men (ages: 45 and 58 years) both presented at our hospital with a high fever. They were found to be HIV-positive with severe immunodeficiency and opportunistic infections. Their laboratory tests showed severe pancytopenia, hypofibrinogenemia, hypertriglyceridemia, and increased levels of inflammatory factors and ferritin. Hemophagocytosis was found in the bone marrow, and abdominal computed tomography or ultrasonography showed splenomegaly. Both patients were diagnosed with infection-induced HLH due to severe immunodeficiency. Given they were both highly immunocompromised, we chose ruxolitinib as a first-line treatment alternative to cytotoxic chemotherapy. Rapid remission of clinical symptoms and normalization of laboratory parameters were achieved after ruxolitinib therapy. Neither patient had any associated adverse drug reactions or other laboratory abnormalities. Both patients were eventually discharged and ruxolitinib was discontinued as their disease alleviated, and they did not show signs of relapse during the 3- and 5-month of follow-up examinations.

Conclusion

We described two cases of AIDS-related secondary HLH treated with ruxolitinib. Our cases highlight the feasibility of using ruxolitinib as a first-line therapy in patients with HIV infection and secondary HLH. Nevertheless, the safety and efficacy of this novel treatment need to be evaluated in large clinical trials in the future.

Secondary Hemophagocytic Syndrome in a Patient with Plasma Cell Myeloma and CNS Involvement Treated with Lenalidomide

We present an extremely rare case report of a 29-year-old multiple myeloma patient with central nervous system involvement and secondary hemophagocytic lymphohistiocytosis (HLH). We observed that HLH was presumably triggered by the immunomodulatory drug—lenalidomide. HLH is frequently misdiagnosed or underdiagnosed. As HLH requires immediate treatment, our report emphasizes the need to consider HLH in the differential diagnosis when the condition of a patient receiving chemotherapy rapidly deteriorates and an infectious etiology is excluded. We furthermore discuss the pathogenesis of HLH, with particular emphasis on drugs affecting the immune system as well as possible therapeutic strategies.

A prediction model for acute kidney injury in adult patients with hemophagocytic lymphohistiocytosis

Background and aims

Hemophagocytic lymphohistiocytosis is a clinical syndrome resulting from abnormally active immune cells and a cytokine storm, with the accompanying phagocytosis of blood cells. Patients with hemophagocytic lymphohistiocytosis often suffer acute kidney injury during hospitalization, which usually signifies poor prognosis. We would like to establish a prediction model for the occurrence of acute kidney injury in adult patients with hemophagocytic lymphohistiocytosis for risk stratification.

Method

We extracted the electronic medical records of patients diagnosed with hemophagocytic lymphohistiocytosis during hospitalization from January 2009 to July 2019. The observation indicator is the occurrence of acute kidney injury within 28 days of hospitalization. LASSO regression was used to screen variables and modeling was performed by COX regression.

Results

In the present study, 136 (22.7%) patients suffered from acute kidney injury within 28 days of hospitalization. The prediction model consisted of 11 variables, including vasopressor, mechanical ventilation, disseminated intravascular coagulation, admission heart rate, hemoglobin, baseline cystatin C, phosphorus, total bilirubin, lactic dehydrogenase, prothrombin time, and procalcitonin. The risk of acute kidney injury can be assessed by the sum of the scores of each parameter on the nomogram. For the development and validation groups, the area under the receiver operating characteristic curve was 0.760 and 0.820, and the C-index was 0.743 and 0.810, respectively.

Conclusion

We performed a risk prediction model for the development of acute kidney injury in patients with hemophagocytic lymphohistiocytosis, which may help physicians to evaluate the risk of acute kidney injury and prevent its occurrence.

Reactive Hemophagocytic Lymphohistiocytosis Secondary to Ovarian Adenocarcinoma: A Rare Case Report

Background

Hemophagocytic lymphohistiocytosis (HLH), a syndrome of immune hyperactivation and abnormal regulation that causes life-threatening inflammation, is mainly characterized by fever, hepatosplenomegaly, cytopenia, and other symptoms. Reactive HLH (rHLH) is typically secondary to immune deregulation caused by underlying rheumatologic, infectious, or malignant conditions. Malignancy-associated HLH (M-HLH) continues to be a critical health problem worldwide. Most malignancies associated with HLH are hematologic tumors, and M-HLH in non-hematologic tumors very rarely occurs.

Case Report

A 34-year-old Chinese woman had a history of persistent fever, acute dizziness, and bicytopenia. She was found to have developed bilateral ovarian cancer. Additional tests showed splenomegaly, hemophagocytes in the bone marrow, low natural killer activity, and hyperferritinemia, which met the diagnostic criteria put forth in the Histiocyte Society HLH-2004. The patient was treated with correcting anemia, increased platelets, and glucocorticoid therapy but showed no response. She progressively deteriorated and died 55 days later.

Conclusion

Hemophagocytic lymphohistiocytosis related to a solid tumor is extremely rare. To the best of the authors’ knowledge, the present case was the first to report rHLH secondary to ovarian adenocarcinoma. It is very significant for a better understanding of the disease mechanisms of HLH and should attract the attention of hematologists and other clinicians as the condition progresses and the cost of treating it increases.

Emerging therapies for juvenile arthritis: agents in early clinical trials

INTRODUCTION

Juvenile idiopathic arthritis (JIA) is the most common chronic inflammatory rheumatic condition in childhood. The management of JIA has been revolutionized thanks to the development of new powerful drugs and the possibility to conduct controlled clinical trials with support from legislative initiatives and availability of international collaborative networks. Trials are still needed in children because we now have new drugs related to specific JIA category.

AREAS COVERED

The review is centered on the latest achievements in the field, focusing on new investigational drugs which are currently or have been recently tested for JIA treatment, encompassing agents in early phase of clinical development.

EXPERT OPINION

Despite the tremendous improvement witnessed in the field of JIA treatment in the past 20 years, there are still many unmet needs to be prioritized. Studies on disease pathogenesis will hopefully help in the identification of new treatment targets for individual JIA categories, that could possibly favor a stricter disease control and contribute to solve the issue of refractory JIA. Novel strategies aimed at the prevention of the risk of long-term joint damage are also desirable, as well as the discovery of predictive biomarkers for treatment efficacy and safety in the individual patient.

One-year-old boy with refractory Listeria monocytogenes meningitis due to persistent hypercytokinemia

We had a case of Listeria monocytogenes (LM) meningitis complicated with hypercytokinemia and hemophagocytic lymphohistiocytosis in a healthy 22-month-old boy. He was admitted to our hospital with a fever, vomiting, mild consciousness disturbances, and extraocular muscle paralysis. Magnetic resonance imaging (MRI) revealed bilateral deep white matter lesions. After receiving ampicillin, meropenem, and gentamicin, his cerebrospinal fluid (CSF) culture results turned negative on the third day of hospitalization. However, the fever intermittently persisted, and it took approximately 40 days to completely resolve. During this period, various inflammatory cytokine levels, particularly neopterin, in the blood and CSF remained elevated. Therefore, long-term administration of corticosteroids in addition to antibiotics was required. The use of dexamethasone appeared to be effective for neurological disorders such as consciousness disturbance and extraocular muscle paralysis associated with abnormal brain MRI findings. LM meningitis may present with encephalopathy and persistent fever due to hypercytokinemia. In such cases, corticosteroid therapy should be considered.

Hemophagocytic lymphohistiocytosis following gene replacement therapy in a child with type 1 spinal muscular atrophy

WHAT IS KNOWN AND OBJECTIVE

Onasemnogene abeparvovec (OA) is the first gene replacement therapy for the treatment of paediatric patients with bi-allelic mutations in the SMN1 gene. Efficacy and safety of OA have been assessed in several studies with promising results, despite rare side effects have been described.

CASE SUMMARY

A 3-year-old child with spinal muscular atrophy was treated with OA and subsequently developed fever, widespread erythematous skin lesions and hepatosplenomegaly. Laboratory tests were suggestive for Hemophagocytic lymphohistiocytosis (HLH).

WHAT IS NEW AND CONCLUSION

To our knowledge, this is the first case of HLH following gene replacement therapy with OA, described in literature.

Mechanistic Insights in Hemophagocytic Lymphohistiocytosis: Subsequent Acute Hepatic Failure in a Multiple Myeloma Patient following Therapy with Ixazomib-Lenalidomide-Dexamethasone

Hemophagocytic lymphohistiocytosis (HLH) is a rare, elusive, and life-threatening condition that is characterized by the pathologic and uncontrolled secondary activation of the cytotoxic T-cells, natural killer cells (NK-cells), and macrophages of the innate immune system. This condition can develop in sporadic or familial contexts associated with hematological malignancies, as a paraneoplastic syndrome, or linked to an infection related to immune system deficiency. This leads to the systemic inflammation responsible for the overall clinical manifestations. Diagnosis should be thorough, and treatment should be initiated as soon as possible. In the current manuscript, we focus on classifying the HLH spectrum, describing the pathophysiology and the tools needed to search for and correctly identify HLH, and the current therapeutic opportunities. We also present the first case of a multiple myeloma patient that developed HLH following therapy with the ixazomib-lenalidomide-dexamethasone protocol.

Characteristics and prognostic value of pleural effusion in secondary hemophagocytic lymphohistiocytosis

The clinical features of patients with secondary hemophagocytic lymphohistiocytosis (sHLH) complicated with pleural effusion have rarely been evaluated. We retrospectively analyzed 203 patients newly diagnosed with sHLH from July 2015 to July 2019 according to the HLH-2004 protocol. Baseline characteristics, laboratory results, and imaging were reviewed. Pleural effusion was found in 58.6% of the studied sHLH population, and characteristic imaging findings were minimal volume and bilaterality. Patients with pleural effusion had lower PLT counts, HB levels and ALB levels as well as higher sCD25 levels than those without pleural effusion (all p values < 0.05). Multivariate analyses showed that lg(sCD25) and PLT ≤ 65 × 10⁹/L were significant risk factors for developing pleural effusion in sHLH. Regarding prognostic value, survival analysis showed a lower survival probability for patients with pleural effusion than for those without pleural effusion (median OS, 90 vs. 164 days, p = 0.028). In multivariate analysis, pleural effusion was an independent prognostic factor for overall survival (OS) (HR 2.68; 95% CI 1.18–6.11, p = 0.019). Pleural effusion is frequently found in patients with sHLH and is associated with greater inflammation and worse outcomes.

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

Background

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

Patients and Methods

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

Results

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

Conclusions

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

Familial Hemophagocytic Lymphohistiocytosis Secondary to PRF1 Mutation

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening hyperinflammatory syndrome that causes systemic inflammation which can progress to multiorgan failure and death. Symptoms and signs commonly seen in HLH include high fever, hepatosplenomegaly, pancytopenia, and hypertriglyceridemia. This report describes the 8-month clinical course of a 17-year-old male with G6PD deficiency who presented with intermittent high fever of unknown origin for 8 months accompanied by pancytopenia and bilateral lower limb weakness. A pathogenic homozygous missense mutation (c.1081A > T p.(Arg361Trp)) in the PRF1 gene was detected by whole exome sequencing (WES). The brain and the whole spine MRI showed leptomeningeal enhancement at different levels involving both the brain and the spine. Therefore, a diagnosis of familial HLH type 2 with CNS involvement was confirmed. Accordingly, treatment with dexamethasone, cyclosporin, and etoposide in addition to intrathecal methotrexate and hydrocortisone was given. The patient showed a dramatic response with significant neurological improvement of the bilateral lower limb weakness. Genetic analysis has helped the patient's family with appropriate genetic counselling. This case highlights the importance of immediate treatment with immunosuppressants and the high clinical suspicion of physicians regarding HLH in areas where consanguinity is common.

Up-regulated serum levels of soluble CD25 and soluble CD163 in pediatric patients with SARS-CoV-2

Similar to hemophagocytic lymphohistiocytosis (HLH), some patients with SARS-CoV-2 have cytokine storm. Serum soluble interleukin-2 receptor (sCD25) and soluble CD163 (sCD163) are potential diagnostic biomarkers for HLH that help in guiding its treatment. This study was the first to investigate serum sCD25 and sCD163 levels in SARS-CoV-2. Serum sCD25 and sCD163 were measured by ELISA in 29 patients with SARS-CoV-2, aged between 2 months and 16 years (13 had COVID-19 and 16 had multisystem inflammatory syndrome in children (MIS-C)), in comparison to 30 age- and sex-matched healthy control children and 10 patients with HLH. Levels of these markers were re-measured in 21 patients with SARS-CoV-2 who were followed up 3 months after recovery. Patients with SARS-CoV-2 had significantly higher serum sCD25 and sCD163 than healthy control children (P < 0.001). SARS-CoV-2 patients had significantly higher sCD25 than patients with HLH (P < 0.05). Serum sCD25 was a good differentiating marker between patients with SARS-CoV-2 and HLH. Although there was a significant decrease of serum sCD25 and sCD163 of the 21 SARS-CoV-2 patients who were followed up, these levels were still significantly higher than the healthy controls levels (P < 0.001).  Conclusion: Serum sCD25 and sCD163 levels were up-regulated in SARS-CoV-2 patients. Serum sCD25 was a good differentiating marker between SARS-CoV-2 and HLH. This initial report requires further studies, on large scales, to investigate the relationship between SARS-CoV-2 and both sCD25 and sCD163, including the disease severity and outcome. The therapeutic role of sCD25 and sCD163 antagonists should also be studied in SARS-CoV-2 patients. What is Known: • Similar to hemophagocytic lymphohistiocytosis (HLH), some patients with COVID-19 have cytokine storm due to excessive pro-inflammatory host response. • Serum soluble interleukin-2 receptor (sCD25) and soluble CD163 (sCD163) are potential diagnostic biomarkers for HLH. Monitoring of serum sCD25 and sCD163 levels can also help in guiding the treatment. What is New: • Serum sCD25 and sCD163 levels are up-regulated in patients with COVID-19, including patients presenting with multisystem inflammatory syndrome in children (MIS-C). • Serum sCD25 is a good differentiating marker between SARS-CoV-2 and HLH.

Diagnosis, treatment, and prevention of severe acute hepatitis of unknown etiology in children

BACKGROUND

Severe acute hepatitis of unknown etiology in children has recently exhibited a global trend of concentrated occurrence. This review aimed to summarize the current available information regarding the outbreak of severe acute hepatitis and introduce our hospital's previous experiences with the diagnosis and treatment of severe acute hepatitis for reference.

DATA SOURCES

Websites including the UK Health Security Agency, European Centre for Disease Prevention and Control, CDC, WHO, and databases including PubMed/Medline, Cochrane Library, Embase and Web of Science were searched for articles on severe acute hepatitis in children.

RESULTS

As of May 26, 2022, a total of 650 cases have been reported in 33 countries; at least 38 (6%) children required liver transplantation, and nine (1%) died. Cases are predominantly aged between 3 and 5 years old, and there are no epidemiological links among them. The common manifestations are jaundice, vomiting and pale stools. Adenovirus tested positive in most cases, and SARS-CoV-2 and other viruses were detected in a few cases, but virus particles were not found in liver tissue. Adenovirus immunohistochemistry showed immunoreactivity in the intrasinusoidal lumen from some liver samples. The hierarchical treatment includes symptomatic and supportive therapy, management of coagulation disorders and hepatic encephalopathy, artificial liver support, and liver transplantation (approximately 6%-10% of cases require liver transplant).

CONCLUSIONS

The etiology of this severe acute hepatitis in children is not clear. The clinical features are severe acute hepatitis with significantly elevated liver enzymes. Clinicians need to be alert to children with hepatitis.

NLRC4 Gene Single Nucleotide Polymorphisms Are Associated with the Prognosis of Hemophagocytic Lymphohistiocytosis

OBJECTIVE

To analyze and study the correlation between NLR family CARD domain-containing 4 (NLRC4) gene single nucleotide polymorphisms and the prognosis of patients with hemophagocytic lymphohistiocytosis (HLH).

METHODS

In this study, we retrospectively studied the clinical data of 62 HLH patients, including 40 males and 22 females. The genomic DNA was extracted, and the genotypes at rs385076 locus and rs479333 locus of the NLRC4 gene were analyzed. The level of blood interleukin-18 (IL-18) was analyzed by enzyme-linked immunosorbent assay (ELISA).

RESULTS

Compared with the TT genotype at the NLRC4 gene rs385076 locus, the mortality of HLH patients with TC genotype and CC genotype was higher (RR = 3.205, 95% CI: 1.277-4.788, p = 0.012; RR = 3.052, 95% CI: 1.098-4.753, p = 0.031). Taking the CC genotype at rs479333 of the NLRC4 gene as a reference, HLH patients with CG genotype and GG genotype had a higher risk of death (RR = 3.475, 95% CI: 1.488-5.775, p = 0.003; RR = 2.986, 95% CI: 1.014-5.570, p = 0.047). NLRC4 gene rs385076 T>C and rs479333 C>G were significantly related to the poor prognosis of HLH patients. The area under the curve (AUC) of the receiver operating curve (ROC) for the prognostic outcome of HLH with serum IL-18 level was 0.6813 (95% CI: 0.5365-0.8260, p = 0.0189). NLRC4 gene rs385076 T>C and rs479333 C>G were related to higher serum IL-18 levels.

CONCLUSION

NLRC4 gene rs385076 T>C and rs479333 C>G are related to the poor prognosis of HLH patients.

Autoimmune Meningitis and Encephalitis

Meningitis and encephalitis are inflammatory syndromes of the meninges and brain parenchyma, respectively, and may be identified either by finding definitive evidence of inflammation on tissue pathology or by cerebrocpinal fluid (CSF) analysis showing pleocytosis or intrathecal antibody synthesis. Clinicians evaluating undifferentiated meningitis or encephalitis should simultaneously consider autoimmune, infectious, and neoplastic causes, using patient risk factors, clinical syndrome, and diagnostic results including CSF and MRI findings to narrow the differential diagnosis. If an autoimmune cause is favored, an important early diagnostic question is whether a specific neural autoantibody is likely to be identified.

Prompt Recognition of Hemophagocytic Lymphohistiocytosis in an Afebrile Patient with Lupus and Staphylococcus aureus Bacteremia

Patient: Male, 43-year-old

Final Diagnosis: Hemophagocytic lymphohistiocytosis (HLH)

Symptoms: Acute kidney injury • anorexia • dyspnea • epistaxis • heart murmur • hepatosplenomegaly • murmur • weakness • weight loss

Medication: —

Clinical Procedure: Bone marrow biopsy • CT scan • echocardiography • plasmapharesis • renal biopsy • ultrasonography

Specialty: Hematology • General and Internal Medicine • Nephrology • Pathology • Rheumatology

HLH-Like Syndrome and Rhabdomyolysis in an Adolescent Patient

Hemophagocytic lymphohistiocytosis (HLH) is a rare heterogeneous group of disorders characterized by immune overactivation. It can occur because of primary genetic mutations or secondary to almost any inflammatory or infectious process. The clinical manifestations of this syndrome are varied and life-threatening and resemble those of many malignancies, infections, sepsis, and multisystem inflammatory syndrome in children. Laboratory abnormalities often are not diagnostic for HLH until late in the disease course, and the laboratory studies are send-out tests at most institutions. Thus, quickly and accurately diagnosing pediatric patients with HLH presents significant challenges to the clinician. Furthermore, there has been recent discussion in the literature regarding the use of diagnostic criteria for HLH. In this case report, we detail an adolescent male individual who developed persistent unexplained fever, rhabdomyolysis, and regional ischemic immune myopathy. To our knowledge, there is no previous report of a pediatric patient with this rare myopathy or HLH presenting with persistent rhabdomyolysis in the literature. The patient was hospitalized for a total of 61 days, with multiple treatments attempted throughout during his course of illness. In this report, we highlight the importance of using diagnostic flexibility when HLH is suspected in pediatric patients and provide insight into the unique challenges of identifying this condition.

Correlation of haemophagocytosis with clinical criteria of haemophagocytic lymphohistiocytosis and recommendations for bone marrow reporting

Haemophagocytic lymphohistiocytosis (HLH) is a rare condition resulting from a dysregulated inflammatory response. Currently there are no guidelines on the reporting of haemophagocytosis on bone marrow biopsy (BM) and lack of evidence on correlation between haemophagocytosis with the clinical diagnostic criteria for HLH. We aimed to assess if the amount of haemophagocytosis identified in the BM correlates with HLH-2004 criteria. Secondary aims were to evaluate inter-observer variability in reporting haemophagocytosis, and to formulate recommendations for screening in bone marrow specimens. A retrospective review of bone marrow biopsies from adult patients under investigation for HLH was undertaken independently by two haematopathologists who were blinded to the original biopsy report. The average number of actively haemophagocytic cells in each slide were quantified. Cases with discordance pertaining to the degree of haemophagocytosis were reviewed by both assessors to reach a consensus. Sixty-two specimens from 59 patients were available for assessment. An underlying haematological condition was identified in 34 cases (58%). There was a significant association between the amount of haemophagocytosis identified on the aspirate samples and the number of HLH-2004 criteria met (p<0.0001). In patients where haemophagocytosis was present (n=31), there was a correlation between the amount of haemophagocytosis and ferritin (p=0.041). Based on our review, we have made recommendations for the reporting of BM haemophagocytosis. Our findings indicate that the amount of haemophagocytosis present on BM samples correlates with the number of HLH-2004 criteria. We found marked interobserver variability which we anticipate can be rectified with our recommendations for reporting.

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

Patient: Male, 34-year-old

Final Diagnosis: Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis

Symptoms: Fever • rash

Medication: —

Clinical Procedure: —

Specialty: Hematology • Immunology • Infectious Diseases

Pathogenesis and Treatment of Refractory Disease Courses in Systemic Juvenile Idiopathic Arthritis: Refractory Arthritis, Recurrent Macrophage Activation Syndrome and Chronic Lung Disease

Systemic juvenile idiopathic arthritis is a distinct and heterogeneous disease presently classified under the umbrella of juvenile idiopathic arthritis, with some patients following a monophasic remitting course, whereas others have persistent disease with chronic organ- and life-threatening complications. Although biologic therapies have revolutionized treatment, recent follow-up studies report significant numbers of children with persistently active disease on long term follow-up. This review focuses on refractory disease courses, specifically refractory arthritis, systemic juvenile idiopathic arthritis with recurrent, or longstanding signs of macrophage activation syndrome, and systemic juvenile idiopathic arthritis associated with suspected, probable, or definite lung disease.

Juvenile Idiopathic Arthritis Treatment Updates

Juvenile idiopathic arthritis is a group of heterogeneous chronic inflammatory arthropathies occurring in childhood without a known cause. This article discusses the key clinical features of juvenile idiopathic arthritis and treatment updates for oligoarthritis, polyarthritis, enthesitis-related arthritis, psoriatic arthritis, and systemic arthritis. Paradigm changes in management include the earlier use of biologic agents and the introduction of biosimilars and targeted synthetic disease modifying agents like tofacitinib. This review summarizes recent developments while considering potential areas for improvement and study.

High Mortality of HLH in ICU Regardless Etiology or Treatment

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

Rapid single-molecule digital detection of protein biomarkers for continuous monitoring of systemic immune disorders

Digital protein assays have great potential to advance immunodiagnostics because of their single-molecule sensitivity, high precision, and robust measurements. However, translating digital protein assays to acute clinical care has been challenging because it requires deployment of these assays with a rapid turnaround. Herein, we present a technology platform for ultrafast digital protein biomarker detection by using single-molecule counting of immune-complex formation events at an early, pre-equilibrium state. This method, which we term "pre-equilibrium digital enzyme-linked immunosorbent assay" (PEdELISA), can quantify a multiplexed panel of protein biomarkers in 10 µL of serum within an unprecedented assay incubation time of 15 to 300 seconds over a 104 dynamic range. PEdELISA allowed us to perform rapid monitoring of protein biomarkers in patients manifesting post-chimeric antigen receptor T-cell therapy cytokine release syndrome, with ∼30-minute sample-to-answer time and a sub-picograms per mL limit of detection. The rapid, sensitive, and low-input volume biomarker quantification enabled by PEdELISA is broadly applicable to timely monitoring of acute disease, potentially enabling more personalized treatment.

Hemophagocytic Lymphohistiocytosis

CONTEXT.—

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

OBJECTIVE.—

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

DATA SOURCES.—

Peer-reviewed literature.

CONCLUSIONS.—

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

Haemophagocytic Lymphohistiocytosis with Leptospirosis: A Rare but Devastating Complication

Introduction

Secondary haemophagocytic lymphohistiocytosis (sHLH), often associated with an array of infections, malignancies, and autoimmune diseases, is rarely seen with leptospirosis, which carries a relatively poor prognosis even with modern state-of-the-art medical care. We describe a patient with leptospirosis complicated by sHLH who succumbed to illness following multiorgan dysfunction. Case Description. A 74-year-old farmer presented with high-grade, unsettling fever for a week. Muddy water exposure and suggestive symptoms prompted investigation and management in the line of leptospirosis (IV ceftriaxone was instituted, and later, MAT (microscopic agglutination test) became positive). Subsequently, he developed severe acute hypoxemia requiring mechanical ventilation and acute renal failure requiring renal replacement therapy. Bone marrow biopsy and markedly elevated serum ferritin and triglyceride levels done on day 10 (with unresolving fever, hepatosplenomegaly, and pancytopaenia) confirmed the diagnosis of HLH. The routine cultures, retroviral studies, CMV, dengue, hanta and mycoplasma antibodies, tuberculosis and COVID-19 PCR, and malaria screening were all normal. There was no improvement of hypoxemia following intravenous methylprednisolone. He died on day 15 despite escalating organ support.

Conclusion

Leptospirosis is a common zoonotic disease in the tropics with significant morbidity and mortality. In the case of severe leptospirosis, overlapping clinical features with sHLH make the diagnosis of the latter challenging. No assessment tools are available to date to predict the risk of developing sHLH in a patient having leptospirosis. Outcome following sHLH due to leptospirosis still remains majorly ominous. A high index of suspicion and low threshold for specific investigations could possibly alter the outcome following such an occurrence.

Ganglionar tuberculosis infection evolving to hemophagocytic lymphohistiocytosis after anti-programmed cell death 1 treatment for high-risk melanoma: a case report

BACKGROUND

Hemophagocytic lymphohistiocytosis is a rare, potentially fatal syndrome of immune hyperactivation. Here we describe a ganglionar tuberculosis evolving to hemophagocytic lymphohistiocytosis following adjuvant immunotherapy in a melanoma patient.

CASE PRESENTATION

A 76-year-old Caucasian male with melanoma started with fever, diffuse petechiae, splenomegaly, anemia, thrombocytopenia, hypofibrinogenemia, and hyperferritinemia 2 months following completion of adjuvant treatment with nivolumab. Positron emission tomography scan showed significant hypermetabolism in cervical, supraclavicular, mediastinal, and abdominal lymph nodes. Bone marrow aspiration demonstrated no alterations, except for a hypercellular pattern. Dexamethasone and intravenous immunoglobulin were started owing to suspicion of hemophagocytic lymphohistiocytosis. Core biopsy of the infracarinal lymph node revealed a chronic granulomatous inflammation and caseous necrosis, with positivity for Mycobacterium tuberculosis by polymerase chain reaction, and treatment for ganglionar tuberculosis was started.

CONCLUSION

This case highlights the challenges involving programmed cell death 1 blockade in high-risk melanoma, in which infections, lymphoproliferative disorders, and sarcoidosis can mimic disease progression and trigger immune-related adverse events.

Histomorphological patterns of regional lymph nodes in COVID-19 lungs

BACKGROUND

A dysregulated immune response is considered one of the major factors leading to severe COVID-19. Previously described mechanisms include the development of a cytokine storm, missing immunoglobulin class switch, antibody-mediated enhancement, and aberrant antigen presentation.

OBJECTIVES

To understand the heterogeneity of immune response in COVID-19, a thorough investigation of histomorphological patterns in regional lymph nodes was performed.

MATERIALS AND METHODS

Lymph nodes from the cervical, mediastinal, and hilar regions were extracted from autopsies of patients with lethal COVID-19 (n = 20). Histomorphological characteristics, SARS-CoV‑2 qRT-PCR, and gene expression profiling on common genes involved in immunologic response were analyzed.

RESULTS

Lymph nodes displayed moderate to severe capillary stasis and edema, an increased presence of extrafollicular plasmablasts, mild to moderate plasmacytosis, a dominant population of CD8⁺ T‑cells, and CD11c/CD68⁺ histiocytosis with hemophagocytic activity. Out of 20 cases, 18 presented with hypoplastic or missing germinal centers with a decrease of follicular dendritic cells and follicular T‑helper cells. A positive viral load was detected by qRT-PCR in 14 of 20 cases, yet immunohistochemistry for SARS-CoV-2 N-antigen revealed positivity in sinus histiocytes of only one case. Gene expression analysis revealed an increased expression of STAT1, CD163, granzyme B, CD8A, MZB1, and PAK1, as well as CXCL9.

CONCLUSIONS

Taken together, our findings imply a dysregulated immune response in lethal COVID-19. The absence/hypoplasia of germinal centers and increased presence of plasmablasts implies a transient B‑cell response, implying an impaired development of long-term immunity against SARS-CoV‑2 in such occasions.

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.

Diagnostic Splenectomy: Characteristics, Pre-Operative Investigations, and Identified Pathologies for 20 Patients

Splenectomy is indicated in cases of trauma to the spleen or hematological and immunological diseases (hereditary spherocytosis, autoimmune cytopenia). Less frequently, splenectomy is performed for diagnostic purposes to complement unsuccessful prior etiological investigations. The splenectomy remains a surgery at risk of complications and should be considered as a last-resort procedure to make the diagnosis and to be able to treat patients. We studied the medical files of 142 patients who underwent a splenectomy for any reason over a 10-year period and identified 20 diagnostic splenectomies. Diagnostic splenectomies were mainly performed to explore unexplained splenomegaly for 13 patients and fever of unknown origin for 10. The other patients had surgery for other causes (cytopenia, abdominal symptoms, suspicion of relapsing malignant hemopathies). Splenectomy contributed to the final diagnosis in 19 of 20 cases, corresponding mostly to lymphoid hemopathies (14/20). The most frequent disease was diffuse large B-cell lymphoma (8/20). Splenectomy did not reveal any infectious disease. The most relevant pre-operative procedures to aid the diagnosis were ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) and immuno-hematological examinations. Diagnostic splenectomy is useful and necessary in certain difficult diagnostic situations. Highlights: Diagnostic splenectomy is still useful in 2020 to diagnose unexplained splenomegaly or fever of unknown origin. Lymphoma was the most common final diagnosis. FDG PET/CT was the most useful tool to aid in the diagnosis.

Central nervous system involvement in adult-onset relapsing hemophagocytic lymphohistiocytosis responsive to maintenance treatment with anakinra

A 43 year-old male presented with a relapsing and progressive systemic inflammatory disorder with central nervous system (CNS) involvement. After a two years follow up, he was diagnosed with hemophagocytic lymphohistiocytosis (HLH), based on clinical, laboratory and radiological findings. Treatment was started with anakinra, a recombinant humanised interleukin-1 (IL-1) receptor antagonist. Clinical response was good. Laboratory and radiological findings showed no disease activity throughout a five years follow-up period. Several immunosuppressive agents have been used in HLH without any good outcomes. This is the first case report of HLH with CNS involvement responsive to chronic treatment with anakinra.

Case of haemophagocytic lymphohistiocytosis following Epstein-Barr virus infection

Haemophagocytic lymphohistiocytosis (HLH) is a rare diagnosis that carries a high degree of mortality. We present this case of a previously healthy 22-year-old woman, who was admitted acutely ill to the hospital. One week prior, she had been seen by her primary care physician for fatigue and malaise. At that time, she was noted to have anterior and posterior cervical lymphadenopathy. She was referred to the emergency room and was diagnosed with acute Epstein-Barr virus (EBV) mononucleosis based on her clinical symptoms and positive heterophile antibody test. She was discharged after an uneventful 48-hour stay on the wards. She represented 7 days after discharge with cough, fatigue, nausea, vomiting, epigastric abdominal pain, diarrhoea, weight loss and subjective fevers. She had also reported haematemesis, epistaxis and melaena. Vital signs included temperature 36.9°C, blood pressure 90/50 mm Hg, heart rate 130 beats per minute and respiratory rate 32 breaths per minute. Physical examination was notable for an acutely ill appearing woman with scleral icterus, hepatosplenomegaly and palpable cervical and axillary lymphadenopathy. Complete blood count showed pancytopaenia with haemoglobin 59 g/L (normal 120-160 g/L), white blood cell count 2.7×10⁹/L (normal 4-10.5×10⁹/L) and platelet count 50×10⁹/L (normal 150-450×10⁹/L). The white blood cell count differential included 58% neutrophils (normal 38%-77%) with immature neutrophils in band form elevated at 45% (normal <14%), 16% lymphocytes (normal 20%-48%), 7% monocytes (normal <12%) and no eosinophils (normal <6%). Blood smear revealed anisocytosis, poikilocytosis and hypochromia. Coagulation panel showed elevated levels of d-dimer level at 1.39 µg/mL (normal <0.45 µg/mL), prolonged prothrombin time at 34.4 s (normal 11-15 s), prolonged activated partial thromboplastin time of 55.6 s (normal 25-34 s), prolonged international normalised ratio at 3.31 (normal <1.1) and low fibrinogen 60 mg/dL (normal >200 mg/dL). Lipid panel showed cholesterol at 114 mg/dL (normal 125-200 mg/dL), triglycerides 207 mg/dL (normal 30-150 mg/dL), high-density lipoprotein cholesterol 10 mg/dL (normal 40-60 mg/dL) and low-density lipoprotein cholesterol 63 mg/dL (normal <100 mg/dL). Other lab abnormalities included elevated ferritin of 6513 ng/mL (normal 10-150 ng/mL) and elevated lactate dehydrogenase of 1071 unit/L (normal 95-240 unit/L). Soluble interleukin-2 receptor alpha level was elevated at 60 727 units/mL (normal 223-710 units/mL). Fluorodeoxyglucose-positron emission tomography (FDG-PET) scan showed abnormal tracer localisation within the paratracheal, hilar, pelvic, abdominal and subcarinal lymph nodes, along with FDG-PET positive hepatosplenomegaly. A bone marrow biopsy showed hypercellular marrow (95% cellularity) with trilineage haematopoiesis, haemophagocytic cells, polytypic plasmacytosis and T-cell lymphocytosis, along with positive latent membrane protein-1 immunohistochemical staining for EBV. EBV quantitative DNA PCR showed >1 million copies. These findings were consistent with a diagnosis of HLH secondary to EBV infection. Despite intense therapy with the HLH-94 protocol, the patient expired from her illness after a prolonged hospital course.

The Presence of Secondary Evans Syndrome in AIDS Patients with Talaromyces marneffei Infection

Objective

Talaromyces marneffei (T.M) is a common opportunistic fungus in human immunodeficiency virus (HIV) infection individual. Secondary Evans syndrome in AIDS patients with Talaromyces marneffei infection has not been reported before. Here, we described cases related to this comorbidity.

Methods

AIDS patients diagnosed with Talaromyces marneffei infection from 2016 to 2020 at Xixi Hospital of Hangzhou were included in this retrospective study.

Results

Total 76 AIDS patients with T.M infection were enrolled. The most common symptoms were fever and cough (70/76; 55/76, respectively). 53/76 (69.74%) patients got positive results of direct antiglobulin test. 14/76 AIDS-T.M patients combined with secondary Hemophagocytic lymphohistiocytosis (HLH). Five patients were diagnosed with AIDS-T.M associated Evans syndrome. There were severe inflammatory reaction, liver dysfunction, coagulation dysfunction and immunodeficiency status in AIDS-T.M patients with secondary Evans syndrome. All patients received antifungal therapy and three patients received corticosteroids for Evans syndrome treatment. One patient died due to sepsis.

Conclusion

AIDS-T.M patients with secondary Evans syndrome is extremely rare and we need to be alert to the occurrence of secondary Evans syndrome in AIDS-T.M patients. Clinicians should timely start effective antifungal treatments with suspicious T.M infection in AIDS patients.

Macrophage Activation Syndrome in Children: Diagnosis and Management

Macrophage activation syndrome is a severe yet under-recognized complication encountered in pediatric rheumatology. It manifests as secondary hemophagocytic lymphohistiocytosis leading to a hyper-inflammatory state resulting from an underlying cytokine storm. If unchecked, it may lead to multiorgan failure and mortality. Early diagnosis and timely initiation of specific therapy is pivotal for a successful outcome. This review outlines the key clinical and laboratory features and management of macrophage activation syndrome.

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

Background

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

Objective

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

Discussion

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

Conclusion

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

Monocytes From Patients With Macrophage Activation Syndrome and Secondary Hemophagocytic Lymphohistiocytosis Are Hyperresponsive to Interferon Gamma

Objective

To investigate the activation of the IFNγ signaling pathway in monocytes of patients with secondary hemophagocytic lymphohistiocytosis (sHLH)/macrophage activation syndrome (MAS) and to evaluate whether levels of phosphorylated STAT1 represent a biomarker for the identification of patients at early stages of the disease.

Methods

Fresh whole blood samples from pediatric patients with active sHLH/MAS, not receiving (n=10) and receiving glucocorticoids (n=14) at time of sampling, were prospectively collected. As disease control groups, patients with active systemic juvenile idiopathic arthritis (sJIA) without MAS, patients with sHLH/MAS in remission and patients with other rheumatic diseases were also sampled. Whole blood cells were left unstimulated or stimulated with increasing concentrations of IFNγ for 10 minutes and the intracellular Tyrosine (701)-phosphorylated STAT1 (pSTAT1) levels were evaluated in monocytes by flow cytometry.

Results

Monocytes from untreated sHLH/MAS patients showed significantly higher basal levels of pSTAT1 compared to those observed in monocytes from glucocorticoid-treated sHLH/MAS patients and from all the other disease controls. In addition, a significant increase in responsiveness to IFNγ, as assessed by increased levels of pSTAT1 following ex vivo stimulation, was observed in monocytes from untreated sHLH/MAS patients. pSTAT1 levels in monocytes distinguished patients with sHLH/MAS not treated with glucocorticoids from patients with active sJIA or with other rheumatic diseases [AUC, 0.93; 95% confidence interval 0.85-1.00, p<0.001]. Statistically significant correlations between IFNG mRNA levels in whole blood cells, circulating IFNγ levels and pSTAT1 levels in sHLH/MAS monocytes were found.

Conclusion

Our data demonstrating higher basal levels of pSTAT1 as well as a hyperreactivity to IFNγ stimulation in monocytes from patients with sHLH/MAS point to perturbations in the activation of downstream IFNγ signaling pathway as a contributor to the hyperinflammation occurring in these patients. Finally, the observation that glucocorticoids affect pSTAT1 levels in vivo, makes it difficult to consider the measurement of pSTAT1 levels as a biomarker to identify patients at early stages of sHLH/MAS in clinical practice.

[Histomorphological patterns of regional lymph nodes in COVID-19 lungs]

Hintergrund

Eine dysregulierte Immunantwort, z. B. in der Form eines Zytokinsturmes, einer Störung des Immunglobulinklassenwechsels, eines sog. antikörpervermitteltem Enhancements oder einer aberranten Antigenpräsentation wurde bereits in schweren Krankheitsverläufen von COVID-19 beschrieben.

Ziel der Arbeit

Zur Charakterisierung der COVID-19-Immunantwort wurde die Histomorphologie der Lymphknoten des pulmonalen Abflussgebietes untersucht.

Material und Methoden

Regionale Lymphknoten des pulmonalen Abflussgebiets wurden bei COVID-19-Autopsien asserviert (n = 20). Deren Histomorphologie, SARS-CoV-2-qRT-PCR sowie Genexpressionsanalysen von gängigen Genen der Immunantwort wurden berücksichtigt.

Ergebnisse

Histologisch zeigten sich ein mäßig- bis schwergradiges Ödem mit Kapillarostase, eine erhöhte Anzahl von extrafollikulären Plasmablasten, milde bis mäßige Plasmazytose, vermehrte CD8⁺-T-Zellen und CD11c/CD68⁺-Histiozyten mit Hämophagozytoseaktivität. Von 20 Fällen wiesen 18 hypoplastische oder fehlende Keimzentren sowie eine Verminderung der follikulären dendritischen Zellen und follikulären T‑Helferzellen auf. In 14 von 20 Fällen war der qRT-PCR-Nachweis von SARS-CoV‑2 positiv, jedoch zeigte sich nur bei einem einzigen Fall eine immunhistochemische Positivität für SARS-CoV-2-N-Antigene in Sinushistiozyten. In Genexpressionsanalysen war eine erhöhte Expression von STAT1, CD163, Granzym B, CD8A, MZB1 und PAK1, neben CXCL9 zu beobachten.

Diskussion

Die Befunde in den Lymphknoten deuten auf eine dysregulierte Immunantwort bei schweren COVID-19-Krankheitsverläufen hin. Insbesondere impliziert das Ausbleiben der Keimzentrumsreaktion und die vermehrte Präsenz von Plasmablasten eine nur transiente B‑Zellreaktion, welche die Entwicklung einer Langzeitimmunität infrage stellt.

Macrophage activation syndrome in a newborn: report of a case associated with neonatal lupus erythematosus and a summary of the literature

BACKGROUND

Macrophage activation syndrome (MAS) is a life-threatening hyperinflammatory syndrome and is caused by a severely dysregulated immune response. It has rarely been associated with neonatal lupus.

CASE PRESENTATION

We present a female neonate with MAS born to a mother who had cutaneous lupus erythematosus with circulating anti-nuclear antibodies (ANA), anti-SSA, anti-SSB and anti-extractable nuclear antigen (anti-ENA) antibodies. Because of neonatal lupus (NLE) with a total atrioventricular block, epicardial pacemaker implantation was required on the sixth day of life. Following surgery she developed non-remitting fever and disseminated erythematous skin lesions. A diagnosis of MAS was made based on these symptoms, with hyperferritinemia, elevated transaminases, hypertriglyceridemia, and a skin biopsy that showed hemophagocytosis. Our patient was treated with steroids for 3 months with good effect. No relapse has occurred.

CONCLUSIONS

MAS is a rare complication of neonatal lupus that may be difficult to diagnose, but needs to be treated promptly. In this article, pathogenesis and overlap of MAS and hemophagocytic lymphohistiocytosis (HLH) has been described. Diagnosis of MAS can be difficult. Different diagnostic criteria are used in both diagnosing MAS and HLH. Validated criteria for diagnosis of MAS in other disease than systemic onset JIA have not been validated yet. In NLE, diagnosing MAS is even more difficult, since skin lesions are already common in NLE. We show the potential additional value of skin biopsy in diagnosing MAS.