Hemophagocytic syndromes (HPSs) including hemophagocytic lymphohistiocytosis (HLH) in adults: A systematic scoping review

Neurological and neuropsychiatric manifestations in a teenager with familial haemophagocytic lymphohistiocytosis with STXBP2 mutation

Familial haemophagocytic lymphohistiocytosis (FHLH) is a rare, life-threatening immune disorder. We report a teenager who experienced several months of low mood, fatigue and progressive lower limb weakness; symptoms which had previously been attributed to a psychosomatic disorder before admission. Clinical findings included lower limb neurological deficits, thrombocytopenia and splenomegaly. Further investigation revealed neuroinflammation on MRI, progressive cytopenias, raised inflammatory markers and elevated protein in the cerebrospinal fluid. Bone marrow aspirate identified haemophagocytosis, and an STXBP2 mutation on genetic testing confirmed FHLH as the diagnosis. Treatment followed the HLH-94 protocol, including intrathecal methotrexate for central nervous system involvement. This case highlights the importance of considering HLH in children with atypical neuropsychiatric presentations. It emphasises the need for early, multidisciplinary intervention for timely diagnosis and effective treatment with immunosuppressants before bone marrow transplant.

Rare manifestation of initial central nervous system involvement in severe fever with thrombocytopenia syndrome-associated encephalopathy/encephalitis: a case report

Severe fever with thrombocytopenia syndrome (SFTS) is a potentially fatal infectious disease if not diagnosed and treated promptly. Typical clinical features include fever, thrombocytopenia, and lymphadenopathy. However, we encountered a case of SFTS in a 60-year-old male who initially did not exhibit these hallmark symptoms. The patient presented with headache and myalgia, but fever did not develop until the 4th day of hospitalization. Initial neuroimaging and cerebrospinal fluid (CSF) analysis revealed no abnormalities. When the fever emerged, follow-up imaging revealed findings consistent with meningitis as a complication of SFTS. The patient was successfully treated with antibiotics and made a full recovery. This case underscores the challenges in diagnosing SFTS in patients who lack fever, CSF pleocytosis, or typical neuroimaging findings at presentation. Additionally, it highlights the importance of differentiating SFTS-related meningitis from other causes of encephalitis to avoid inappropriate treatments, such as immunosuppressive therapy, which could worsen viral infections.

Clinical Features, Treatment, and Outcomes of Nivolumab-Induced Hemophagocytic Lymphohistiocytosis

Haemophagocytic lymphohistiocytosis (HLH) is a rare and fatal immune-related event of nivolumab. The clinical features of nivolumab-induced HLH are unclear. The aim of this study was to investigate the clinical features, treatment, and outcome of nivolumab-induced HLH to provide information for prevention and treatment. We collected nivolumab-induced HLH-related case reports for retrospective analysis by searching the Chinese and English databases from inception to March 31, 2024. HLH developed in 24 patients, with a median age of 57 years (range: 26, 86). The onset of HLH symptoms ranged from 3 days to 68 weeks after administration, with a median time of 5.5 weeks. Fever (87.5%) was the most common symptom and could be accompanied by splenomegaly (66.7%) and hepatomegaly (20.8%). Laboratory tests revealed hemocytopenia, hypertriglyceridemia, hypofibrinogenemia, hyperferritinemia, increased sCD25, and decreased natural killer cell activity. Bone marrow biopsy showed hemophagocytosis (62.5%). After discontinuing nivolumab, HLH patients receiving systemic steroids, tocilizumab, and anakinra showed positive results. As a rare adverse reaction of nivolumab, HLH requires rapid diagnosis and appropriate treatment based on clinical symptoms and laboratory tests. Tocilizumab and anakinra can be used as an effective treatment against the steroid HLH.

Disseminated histoplasmosis and hemophagocytic lymphohistiocytosis: A case report

Hemophagocytic lymphohistiocytosis (HLH) is an immune deregulatory disorder resulting in severe inflammation and potentially fatal complications involving the bone marrow, liver, or brain; HLH can be considered primary. Secondary HLH is often associated with a specific trigger, including infectious trigger that could be bacterial, viral, fungal or parasitic. Histoplasmosis-associated HLH is a relatively rare but previously reported complication. This case report presents a patient with HLH caused by disseminated histoplasmosis who was treated with etoposide, rituximab, amphotericin B, and itraconazole. This case report aims to highlight the importance of keeping a broad differential for when patients present with fevers of unknown origin.

Health-Related Quality of Life Among Discharged Patients With Hemophagocytic Lymphohistiocytosis: A Follow-Up Study

PURPOSE

Evaluating the post-discharge health-related quality of life (HRQoL) in hemophagocytic lymphohistiocytosis (HLH) and exploring its influencing factors.

PATIENTS AND METHODS

The study was conducted at a regional pediatric medical center and involved pediatric patients diagnosed with HLH between July 2017 and July 2022. Healthy children of the same age and sex were included as the control group. The HRQoL and its associated factors in pediatric patients were assessed using the PedsQL 4.0 Parent Proxy Report and a general information survey.

RESULTS

In the first year following diagnosis, psychological health and overall score in HLH patients were worse than those of the control group. However, scores for emotional functioning, school functioning, physical health, psychosocial health, and overall scores in the HLH group increased over the years since diagnosis. By the 5-year post diagnosis, there were no significant differences between the HLH group and the control group in social functioning, school functioning, physical health, psychosocial health, and overall scores (p > 0.05). Generalized linear model analysis revealed that HLH patients who underwent transplantation have worse social functioning, physical health, overall score, while HLH patients with HLH recurrence have worse social functioning, psychosocial health, overall score (p < 0.05).

CONCLUSION

The HRQoL of HLH patients is compromised after discharge; however, it progressively returns to levels comparable to those of healthy cohorts over time since diagnosis. Transplantation, and HLH recurrence are identified as factors affecting the HRQoL in HLH patients.

Nationwide Analysis of Variables Associated With Sarcoid Inpatient Mortality

BACKGROUND

Sarcoidosis is a multisystem autoimmune disease that can result in significant morbidity and mortality. This study aims to identify factors associated with in-hospital death for sarcoid patients on a national level.

METHODS

We performed a medical records review study of all adult sarcoid hospitalizations from 2016 to 2020 National Inpatient Sample database. A univariable screen followed by multivariable analysis was completed to identify predictors of in-hospital death among sarcoid patients.

RESULTS

There were 405,650 admissions with a diagnosis of sarcoidosis, 10,210 of whom died. Multivariable analysis showed the following factors were independently associated with a higher odds of in-hospital death: age (odds ratio [OR], 1.03; 95% confidence interval [CI], 1.026-1.034), Charlson Comorbidity Index (OR, 1.09; 95% CI, 1.066-1.116), male sex (OR, 1.21; 95% CI, 1.101-1.331), other race (OR, 1.45; 95% CI, 1.073-1.954), arrhythmia/heart blocks (OR, 1.80; 95% CI, 1.617-1.995), cirrhosis/hepatic failure (OR, 8.26; 95% CI, 6.928-9.844), hemophagocytic lymphohistiocytosis (OR, 11.15; 95% CI, 4.172-29.802), infection (OR, 3.31; 95% CI, 3.007-3.633), interstitial lung disease (OR, 1.31; 95% CI, 1.193-1.438), heart failure/myocarditis (OR, 1.29; 95% CI, 1.157-1.436), neurologic diagnoses (OR, 1.37; 95% CI, 1.241-1.502), and pulmonary hypertension (OR, 1.47; 95% CI, 1.305-1.652).

CONCLUSIONS

Our multiyear national analysis showed that 2.5% of hospital admissions with a sarcoid diagnosis ended in death. The following factors were associated with death: age, Charlson Comorbidity Index, male sex, other race, arrhythmia/heart blocks, cirrhosis/hepatic failure, hemophagocytic lymphohistiocytosis, infection, interstitial lung disease, heart failure/myocarditis, neurologic diseases, and pulmonary hypertension. This information can help clinicians by improving awareness of these life-threatening complications because early recognition and intervention may improve inpatient sarcoid outcomes.

Immunotherapy-related secondary hemophagocytosis in a glioblastoma patient: response to cytokine-directed therapy

Hemophagocytic Lymphohistiocytosis (HLH) is a severe and potentially life-threatening condition characterized by an excessive and uncontrolled activation of the immune system. ICI-related hemophagocytic lymphohistiocytosis (irHLH) is a rare immune-related adverse event with an incidence of 0.03% to 0.4%. Although rare, it can be potentially lethal, with a high mortality rate of up to 50% in some cases. We present a patient with recurrent glioblastoma who developed Hemophagocytic Lymphohistiocytosis s a result of nivolumab treatment and was subsequently managed with cytokine-directed therapy (tocilizumab). Early diagnosis and treatment of Hemophagocytic Lymphohistiocytosis (HLH) associated with immune checkpoint inhibitors (ICIs) are indeed crucial due to the potentially life-threatening nature of the condition.Cytokine-based treatments (such as anti-IL-6) may be appropriate for patients who do not respond to high-dose steroids.

Long-term remission in a patient with NK/T cell intravascular lymphoma with autologous hematopoietic cell transplantation

Intravascular lymphoma (IVL) is a rare subtype of lymphoma, mostly of B-cell origin. A few cases of IVL have been reported as having NK/T cell origins (IVNKTL). These cases are known to be fatal, especially when systemic symptoms are present. We report the case of a patient of IVNKTL who was refractory to initial treatment and received autologous hematopoietic stem cell transplantation (auto-HSCT). She has maintained complete remission (CR) for over eight years. Our case might support the evidence of auto-HSCT for the treatment of IVNKTL with chemosensitivity.

Prognostic Impact of Aetiology in Adult Hemophagocytic Lymphohistiocytosis: Insights from an Intensive Care Unit Experience

Background

Hemophagocytic lymphohistiocytosis (HLH) is a rare, life-threatening hyperinflammatory syndrome marked by excessive immune activation. It can be triggered by various factors, including infections, malignancies, and autoimmune diseases, making the diagnosis challenging due to its overlap with other severe conditions.

Case reports

We discuss two intensive care unit (ICU) cases illustrating the diverse manifestations of HLH and the critical importance of early recognition and treatment. The first case involves natural killer-cell leukaemia, and the second, a suspected viral trigger. Both highlight the necessity of a multidisciplinary approach in diagnosis and management, emphasizing the complexity of HLH in ICU settings.

Conclusions

High mortality rates, particularly in malignancy-associated HLH, underscore the importance of tailored treatment strategies based on the underlying aetiology.

LEARNING POINTS

Hemophagocytic lymphohistiocytosis (HLH) in adults can arise from a variety of triggers, including infections and malignancies, each influencing disease progression and prognosis differently. Recognizing these underlying aetiologies is crucial for tailoring management strategies and anticipating clinical outcomes.Due to its life-threatening nature, HLH requires prompt diagnosis and a coordinated, multidisciplinary approach. Early intervention, incorporating immunosuppressive therapies and supportive care, is essential to improve patient outcomes, particularly in intensive care unit settings where disease severity is often pronounced.Utilizing diagnostic tools such as the HScore and HLH-2004 criteria can facilitate early identification of HLH in critically ill patients with unexplained inflammatory symptoms. These tools, along with a high index of suspicion, help distinguish HLH from other hyperinflammatory conditions, enabling timely and appropriate therapeutic interventions.

Reactive hemophagocytic lymphohistiocytosis: Epidemiological, clinico-biological and etiological profile

Hemophagocytic lymphohistiocytosis (HLH) is an hyperinflammatory state resulting from increased secretion of proinflammatory cytokines, which are responsible for clinical, biological and cytological manifestations.

OBJECTIVE

The aim of our study is to describe the epidemiological, clinical, biological, etiological and evolutionary profile of HLH in Tunisia.

METHODS

A retrospective study that involved patients, with images of hemophagocytosis in myelograms analyzed at the laboratory of biological hematology of the University Hospital "Hédi-Chaker" of Sfax-Tunisia, followed at these departments: hematology, internal medicine, department of infectious-diseases and department of gastroenterology, (June2017- May2021). First, we identified all patients with hemophagocytosis images. Secondly, we selected the patients who fulfilled the diagnostic criteria of the HLH-2004-score.

RESULTS

Nineteen patients were included in this study. Nine men and 10 women with a mean age of 37.95 years. Fever was present in all patients. Organomegaly was described in 74% of cases. The most frequent cytopenia was anemia (100%). Hypertriglyceridemia was noted in 79% of cases and hyperferritinemia (> 500 ng/mL) was ubiquitous. In myelogram, 68% of patients had slides showing numerous or very numerous images of hemophagocytosis. The infectious pathology was the most common cause of HLH (42%). No cause was found in 10% of cases. The corticosteroid therapy at a dose of 1 mg/kg/day was prescribed in 89% of our patients. The overall evolution was favorable in 58% of cases. The mortality was not associated with the causal pathology (p=0.218).

CONCLUSION

Secondary HLH is likely to be under-recognized, which contributes to its high morbidity and mortality. Early recognition is crucial for any reasonable attempt at curative therapy.

Fatal disseminated Mycobacterium avium infection with bone marrow infiltration and hemophagocytic syndrome

Disseminated non-tuberculous mycobacterial (NTM) infection can affect patients with underlying immunosuppressive conditions. Despite being rare, delay in diagnosis can lead to life-threatening uncontrolled immune response and hemophagocytic syndrome (HPS). We report a case of a 63-year-old female with suspected autoimmune disease, in whom HPS was diagnosed according to HLH-2004 criteria and H-score. Mycobacterium avium (M. avium) was isolated from blood culture, bronchoalveolar lavage (BAL) and bone marrow biopsy. In immunosuppressed patients, early clinical suspicion and prompt microbiological diagnosis of mycobacterial infection together with drug susceptibility tests (DST)-based treatment, as well as HPS, are pivotal to increase the likelihood of treatment success.

Fever of Unknown Origin: A Rare Diagnosis Requiring High Suspicion

Fever is a classic reason for hospital visits, sometimes requiring admission. Its etiologies are numerous, ranging from simple and relatively common conditions to rare and complex pathologies, for which the differential diagnosis can present a true challenge for internists. A 78-year-old healthy female is referred to the emergency department due to marked fatigue for the past four months, with no other symptoms. Physical examination revealed fever, significant lower limb edema, and low blood pressure. Laboratory results revealed anemia and thrombocytopenia, associated with high ferritin and lactate dehydrogenase levels (1924 U/L and 1519 U/L, respectively) and mild hyponatremia (133 mEq/L). A thoracic-abdominal-pelvic CT scan showed only a splenomegaly of 17 cm without other significant findings. No microorganisms were found in multiple cultural samples, and fever persisted despite two courses of antibiotics. Viral serologies and zoonosis panel were negative. A bone marrow study was conducted to help explain the cytopenias, which revealed hemophagocytic cells, confirming the diagnosis of hemophagocytic syndrome. She started with systemic corticosteroid therapy, which improved her symptoms, and a few days later, it was confirmed a diffuse large B-cell lymphoma was the etiology. Because of its mostly unspecific manifestations, hemophagocytic syndrome requires a high degree of suspicion for timely diagnosis and treatment.

A Novel Engineering Cell Therapy Platform Mimicking the Immune Thrombocytopenia-Derived Platelets to Inhibit Cytokine Storm in Hemophagocytic Lymphohistiocytosis

Hemophagocytic lymphohistiocytosis (HLH) is a common and highly fatal hyperinflammatory syndrome characterized by the aberrant activation of macrophages. To date, there is a lack of targeted therapies for HLH. It is validated that macrophages in HLH efficiently phagocytose anti-CD41-platelets (anti-CD41-PLTs) from immune thrombocytopenia (ITP) patients in previous research. Hence, the pathological mechanisms of ITP are mimicked and anti-CD41-PLTs are utilized to load the macrophage-toxic drug VP16 to construct macrophage-targetable engineered platelets anti-CD41-PLT-VP16, which is a novel targeted therapy against HLH. Both in vitro and in vivo studies demonstrate that anti-CD41-PLT-VP16 has excellent targeting and pro-macrophage apoptotic effects. In HLH model mice, anti-CD41-PLT-VP16 prevents hemophagocytosis and inhibits the cytokine storm. Mechanistic studies reveal that anti-CD41-PLT-VP16 increases the cytotoxicity of VP16, facilitating precise intervention in macrophages. Furthermore, it operates as a strategic "besieger" in diminishing hyperinflammation syndrome, which can indirectly prevent the abnormal activation of T cells and NK cells and reduce the Ab-dependent cell-mediated cytotoxicity effect. The first platelet-based clinical trial is ongoing. The results show that after treatment with anti-CD41-PLT-VP16, HLH patients have a threefold increase in the overall response rate compared to patients receiving conventional chemotherapy. In conclusion, anti-CD41-PLT-VP16 provides a general insight into hyperinflammation syndrome and offers a novel clinical therapeutic strategy for HLH.

Prominent tissue hemophagocytic lymphohistiocytosis obscuring primary cutaneous gamma/delta (γδ) T-cell lymphoma

Primary cutaneous gamma/delta (γδ) T-cell lymphoma (PCGDTCL) is a rare, aggressive malignant neoplasm of γδ T lymphocytes arising within the skin and subcutis. We present a challenging case of PCGDTCL diagnosed in a 35-year-old male soldier who presented with constitutional symptoms, pancytopenia, hemophagocytic lymphohistiocytosis (HLH), disseminated lymphadenopathy, and cutaneous lesions on his extremities and back following a deployment to Iraq and Syria. Histopathologic evaluation of an excisional biopsy showed that PCGDTCL can be focal, localized to the subcutaneous adipose tissue, and obscured by predominant HLH in the surrounding tissues. Pathologists should recognize that the diagnosis of PCGDTCL may be confounded by florid HLH and require multiple biopsies and a comprehensive immunohistochemical panel.

Hemophagocytic Lymphohistiocytosis Presenting With ARDS in a Young Adult: A Case Report

Fever is common in the ICU, with infectious causes accounting for only half of febrile episodes. This case examines a young male who developed high-grade fevers and pulmonary infiltrates unresponsive to broad-spectrum antibiotics. Examination revealed hepatosplenomegaly, hypertriglyceridemia, anemia, and thrombocytopenia, suggestive of hemophagocytic lymphohistiocytosis (HLH). Meeting 5 of 8 HLH criteria, high-dose steroids were administered, resulting in clinical improvement. HLH, with a high mortality risk, demands early recognition, complicated by nonspecific symptoms. This case highlights the rare manifestation of ARDS in HLH, adding diagnostic challenges in critical care settings.

Comprehensive mapping of immune perturbations associated with secondary hemophagocytic lymphohistiocytosis

Secondary hemophagocytic lymphohistiocytosis (sHLH) is a hyperinflammatory syndrome characterized by immune disorders. It is imperative to elucidate the immunophenotypic panorama and the interactions among these cells in patients. Human peripheral blood mononuclear cells were collected from healthy donors and sHLH patients and tested using multicolor flow cytometry. We used FlowSOM to explore and visualize the immunophenotypic characteristics of sHLH. By demonstrating the phenotypes of immune cells, we discovered that sHLH patients had significantly higher levels of CD56+ monocytes, higher levels of myeloid-derived suppressor cells, low-density neutrophil-to-T cell ratio, and higher heterogeneous T cell activation than healthy donors. However, natural killer cell cytotoxicity and function were impaired. We then assessed the correlations among 30 immune cell types and evaluated metabolic analysis. Our findings demonstrated polymorphonuclear myeloid-derived suppressor cells, CD56+ monocytes, and neutrophil-to-T cell ratio were elevated abnormally in sHLH patients, which may indicate an association with immune overactivation and inflammatory response. We are expected to confirm that they are involved in the occurrence of the disease through further in-depth research.

GATA2 deficiency and hemophagocytic lymphohistiocytosis (HLH): a systematic review of reported cases

PURPOSE

GATA2 deficiency is an autosomal dominant disease that manifests with a range of clinical symptoms, including increased susceptibility to viral, bacterial, and fungal infections. Furthermore, the increased susceptibility to infections in GATA2 deficiency can trigger hemophagocytic lymphohistiocytosis (HLH) in these patients. Our systematic review evaluates reported cases of GATA2 deficiency and HLH in the literature.

METHODS

A systematic review of case reports was conducted following PRISMA 2020 guidelines, encompassing studies retrieved from Ovid MEDLINE ALL, Embase via Ovid SP, Scopus, Web of Science, and Google Scholar from inception until June 14, 2024. This review included studies reporting patients diagnosed with GATA2 deficiency or having a documented history of the condition, who subsequently developed or were concurrently diagnosed with HLH. Various study types were considered, such as case reports, case series, letters to editors, original articles, correspondences, and commentaries, without any restrictions on language.

RESULTS

In our systematic review, 15 studies from 2016 to 2024 were analyzed, encompassing 23 patients with GATA2 deficiency and HLH. the mean (SD) age of patients was 23.48 (10.54) years, ranging from 7 to 57 years. These patients exhibited diverse genetic mutations and a spectrum of infections, particularly Mycobacterium avium (M. avium), Mycobacterium kansasii (M. kansasii), Epstein-Barr virus (EBV), cytomegalovirus (CMV), varicella-zoster virus (VZV), herpes simplex virus (HSV), and influenza A, often leading to HLH. Family histories of GATA2-deficient patients with HLH occasionally reveal confirmed GATA2 mutations or suspicious cases among first-degree relatives. Hematopoietic stem cell transplantation (HSCT) was performed in 8 patients with GATA2 deficiency and HLH. Among them, 6 patients survived post-therapy, while 2 patients died following HSCT. Currently, 1 patient is being considered for HSCT. The overall mortality rate among GATA2 deficiency patients who experienced HLH was 39.13%.

CONCLUSIONS

This systematic review highlights GATA2 deficiency's association with diverse infections triggering HLH, emphasizing early infection management to mitigate mortality risks. This comprehensive analysis contributes to scientific knowledge, offering important insights for clinicians and researchers in diagnosing and managing this rare condition.

CRP and sCD25 help distinguish between adult-onset Still's disease and HLH

OBJECTIVE

Adult-onset Still's disease (AOSD) and secondary hemophagocytic lymphohistiocytosis (sHLH) are both hyperferritinemic cytokine storm syndromes that can be difficult to distinguish from each other in hospitalized patients. The objective of this study was to compare the inflammatory markers ferritin, D-dimer, C-reactive protein (CRP), and soluble CD25 (sCD25) in patients with AOSD and sHLH. These four markers were chosen as they are widely available and represent different aspects of inflammatory diseases: macrophage activation (ferritin); endothelialopathy (D-dimer); interleukin-1/interleukin-6/tumour necrosis factor elevation (CRP) and T cell activation (sCD25).

METHODS

This was a single-center retrospective study. Patients diagnosed by the Hematology service at Vancouver General Hospital for AOSD or sHLH from 2009 to 2023 were included.

RESULTS

There were 16 AOSD and 44 sHLH patients identified. Ferritin was lower in AOSD than HLH (median 11 360 μg/L vs. 29 020 μg/L, p = .01) while D-dimer was not significantly different (median 5310 mg/L FEU vs. 7000 mg/L FEU, p = .3). CRP was higher (median 168 mg/L vs. 71 mg/L, p <.01) and sCD25 was lower (median 2220 vs. 7280 U/mL, p = .004) in AOSD compared to HLH. The combined ROC curve using CRP >130 mg/L and sCD25< 3900 U/mL to distinguish AOSD from HLH had an area under the curve (AUC) of 0.94 (95% confidence interval 0.93-0.97) with sensitivity 91% and specificity 93%.

CONCLUSIONS

These findings suggest that simple, widely available laboratory tests such as CRP and sCD25 can help clinicians distinguish AOSD from HLH in acutely ill adults with extreme hyperferritinemia. Larger studies examining a wider range of clinically available inflammatory biomarkers in a more diverse set of cytokine storm syndromes are warranted.

Haemophagocytic lymphohistiocytosis secondary to disseminated histoplasmosis in a patient with leprosy

Multidrug therapy has significantly reduced the global burden of Hansen's disease; however, complications from long-term treatment persist. A male resident of southern Kentucky, in his 30s and of Micronesian descent, presented with worsening abdominal pain associated with anorexia, fatigue, functional decline and occasional haemoptysis. He was compliant with multidrug therapy for leprosy. Laboratory investigations revealed pancytopenia. He was initially treated under a sepsis protocol and later switched to high-dose steroids due to a suspected immune reaction from missed corticosteroid doses. Despite aggressive treatment for refractory pancytopenia, the patient's condition deteriorated, and he passed away from cardiac arrest. Posthumous bone marrow biopsy revealed haemophagocytic lymphohistiocytosis secondary to disseminated histoplasmosis with bone marrow infiltration. This case highlights the importance of proactive fungal screening in immunocompromised leprosy patients, particularly in endemic regions, as early detection and timely intervention can prevent severe complications.

Hemophagocytic Lymphohistiocytosis Triggered by Herpes Simplex Virus 1 and 2: A Narrative Review

Introduction: Hemophagocytic lymphohistiocytosis (HLH) is a rare, life-threatening syndrome characterized by an uncontrolled hyperinflammatory reaction. HLH is classified into primary (familial) and secondary (acquired). Secondary HLH is commonly triggered by infections, with viral infections being a leading cause. Its epidemiology and clinical features in cases associated with herpes simplex virus 1 and 2 remain underexplored. This study aimed to review all previously described cases of HSV-1 or -2-triggered HLH and provide information about this syndrome's epidemiology, microbiology, clinical characteristics, treatment, and outcomes. Methods: A narrative review was performed based on a search in PubMed, the Cochrane Library, and Scopus. Studies published until 27 April 2024 providing relevant data for HLH due to HSV 1 and 2 in humans were included. Results: We identified 29 eligible studies reporting HLH due to HSV 1 and 2, involving 34 patients. Half of them were adults, and half were neonates. Fever and splenomegaly were the most common clinical findings. Most patients were diagnosed with HSV-1 (64.7%), with PCR being the primary diagnostic method. The median duration of in-hospital treatment was 21 days, with acyclovir and steroids being the mainstays of therapy. The overall mortality rate was 41.2%, and AST levels emerged as an independent predictor of mortality. Conclusions: Our findings underscore the need for heightened awareness surrounding HLH triggered by HSV 1 and 2 and the importance of prompt diagnosis and tailored treatment approaches.

Omission of etoposide in the treatment of haemophagocytic lymphohistiocytosis secondary to primary central nervous system lymphoma with satisfactory response

Haemophagocytic lymphohistiocytosis (HLH) is a hyperinflammatory condition that can be either familial or acquired and, if untreated, frequently results in multiorgan failure and death. Treatment of HLH typically requires a combination of glucocorticoids and cytotoxic chemotherapy. We describe the case of a woman who presented with signs and symptoms concerning for HLH who was later found to have a primary central nervous system (CNS) diffuse large B-cell lymphoma. Her HLH symptoms were successfully treated with high doses of dexamethasone, and her primary CNS lymphoma was treated with high-dose methotrexate and rituximab. This is a rare case of HLH secondary to primary CNS lymphoma where HLH was controlled with steroids alone and did not require the use of an etoposide-based regimen or cyclophosphamide, doxorubicin, vincristine and prednisone.

Hemophagocytic Lymphohistiocytosis Induced by Brucellosis: A Case Report

Hemophagocytic lymphohistiocytosis (HLH) is a hyper-inflammatory condition triggered by infections, malignancies, or autoimmune conditions. Brucellosis is a zoonotic disease contracted through exposure to infected animals or consumption of unpasteurized dairy products. The complications of both pathologies may be fatal. This report presents a rare instance of HLH induced by Brucellosis, highlighting the need for increased recognition of this life-threatening association.

Average Temperature as a Marker of Lymphoma-Associated HLH

METHODS

This retrospective analysis aimed to assess whether a 12-hour mean temperature (measured around either diagnosis of HLH or peak ferritin value) has value as a quick and simple diagnostic test for HLH in people with lymphoproliferative disease (LPD). Hospital records from 2018 to 2022 were retrospectively screened for patients with LPD and peak ferritin during admission to hospital >3000ng/mL. Patients were grouped as either HLH or non-HLH after consensus discussion at a multi-disciplinary meeting with access to full, detailed patient records and H-scores.

RESULTS

The total cohort of 23 patients consisted of 12 with HLH and 11 grouped as non-HLH. 12-hour mean temperature at HLH diagnosis was 38.6 °C in the HLH cohort and 37.5 °C measured at the point of peak ferritin measurement in non-HLH groups. It was also positively correlated with HLH status (P = 0.001) and showed high retrospective sensitivity and specificity for HLH above 37.7 °C.

CONCLUSION

These results demonstrate that a 12-hour mean temperature may add value and diagnostic certainty to the first-line investigations for HLH associated with LPD. The moderately high sensitivity and specificity achieved with this dataset supports the need for further research into whether the test retains validity in larger patient groups.

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

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

Successful Second CBT for Graft Failure After First CBT for Adult-Onset Familial Hemophagocytic Lymphohistiocytosis Type 3: A Case Report

Familial hemophagocytic lymphohistiocytosis (FHL) is a rare inherited autosomal recessive immune deficiency that usually manifests during infancy or early childhood, rarely occurring in adults. Hematopoietic stem cell transplantation (HSCT) is the only curative treatment for FHL. However, optimal conditioning regimens for adult-onset FHL have not yet been established. Herein, we report a case of adult-onset FHL. A 37-year-old man presented with fever, liver dysfunction, and pancytopenia, which improved temporarily with corticosteroid therapy. However, he later developed encephalitis and myelitis. Genetic analysis revealed rare variants of UNC13D (c.2367+1 g>a and c.2588 g>a), which were compound heterozygous pathogenic mutations. FHL type 3 was diagnosed, and treatment based on the hemophagocytic lymphohistiocytosis (HLH) 1994 protocol was initiated. The patient underwent cord blood transplantation (CBT) with myeloablative conditioning using fludarabine, melphalan, and total-body irradiation (TBI), which resulted in graft rejection. The patient was successfully rescued by a second CBT following reduced-intensity conditioning with fludarabine, cyclophosphamide, and TBI. Although graft failure is an important complication especially in CBT, it could be managed by appropriate treatment, and that cord blood would be a promising alternative source with the advantages of rapidity and avoidance of related donors with a high risk of harboring the same genetic mutation.

Hemophagocytic Lymphohistiocytosis in a Remote Kidney Transplant Recipient Triggered by HSV Infection With Complete Recovery: An Educational Case Report

Rationale

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening disease characterized by excessive immune activation. It is more commonly seen in children but increasingly recognized in adults. Primary HLH relies on a genetic predisposition, whereas secondary HLH develops in the context of infections, malignancies, or autoimmune diseases. Hemophagocytic lymphohistiocytosis has been rarely described in patients on immunosuppressive therapy after kidney transplant. Here, we describe a case of HLH in a patient with a remote history of kidney transplant, triggered by a viral infection.

Presenting Concerns

A 45-year-old female, with a kidney transplant in 2009 for IgA nephropathy, presented with fever, vomiting, and back pain of 1-week duration. She was on triple immunosuppression consisting of daily doses of prednisone 5 mg, azathioprine 100 mg, and tacrolimus extended release 1 mg, and a baseline creatinine of 130 µmol/L.

Diagnosis

Initial investigations showed anemia, leukopenia, elevated serum creatinine, transaminitis, and markedly increased ferritin of 67 600 µg/L which prompted a bone marrow biopsy to rule out HLH. The bone marrow showed an increased proportion of CD68+ cells (macrophages) with more than 5 in 1000 hemophagocytic macrophages. Her soluble IL-2 receptor (CD25) level was 3406 pg/mL (606-2299 pg/mL) which was mildly elevated. She fulfilled 4 of the 8 criteria for HLH and with an H score was 223 which suggested a diagnosis of HLH with 96.9% probability. An extensive secondary workup for possible triggers for HLH led to a swab from genital ulcers that was positive for herpes simplex virus (HSV) type 2. The polymerase chain reaction (PCR) in the blood for HSV type 2 was also positive.

Interventions

Given the diagnosis of HSV type 2 as the putative trigger for HLH, she was started on parenteral acyclovir for 2 weeks followed by oral valacyclovir for 2 more weeks. In the context of infection, the azathioprine was stopped while low-dose steroid and tacrolimus were continued.

Outcomes

With the initiation of treatment for HSV infection, leukopenia, creatinine, and transaminases improved along with ferritin levels. At her 6-month follow-up, her blood counts and liver enzymes had normalized, and ferritin was 566 µg/L.

Teaching points

Hemophagocytic lymphohistiocytosis is a rare disease in kidney transplant recipients with a high mortality rate. It can occur even in remote kidney transplant recipients so a high degree of suspicion is necessary to lead to a prompt diagnosis. Infections are common triggers for secondary HLH. Early identification and treatment of the triggering infection may improve outcomes.

A Case Report of Pregnancy Complicated with Primary Hemophagocytic Lymphohistiocytosis

Background

Hemophagocytic lymphohistiocytosis (HLH) is a severe hyperinflammatory syndrome characterized by excessive activation of NK cells and cytotoxic T lymphocytes, subsequently leading to macrophage activation and increased cytokine production. Misdiagnosis due to nonspecific clinical presentations and inadequate understanding of the disease can significantly jeopardize the safety of both the mother and the infant. We report a case of pregnancy combined with HLH and conduct a literature review to provide insights into the diagnosis and treatment of pregnancy-related HLH.

Case Presentation

We discussed a case of a pregnant woman with persistent postpartum fever, serum ferritin, and elevated liver function, who failed to respond to repeated anti-infective therapy and was diagnosed with HLH after multidisciplinary diagnostic treatment. We gave dexamethasone treatment, and the patient's temperature and blood cells quickly returned to normal. Finally, exome sequencing revealed heterozygous variation in UNC13D gene, so we considered this case as pregnancy combined with primary HLH (pHLH).

Conclusion

We report the case of HLH diagnosed during pregnancy and show that early diagnosis and timely intervention can prevent rapid disease progression, reduce maternal mortality rates, and improve survival rates. Additionally, molecular genetic testing can confirm pathogenic gene mutations, providing essential genetic counseling for patients with pHLH who plan to conceive a healthy child.

Severe fever with thrombocytopenia syndrome with central nervous system symptom onset: a case report and literature review

BACKGROUND

Severe fever with thrombocytopenia syndrome (SFTS) is a natural focal disease transmitted mainly by tick bites, and the causative agent is SFTS virus (SFTSV). SFTS can rapidly progress to severe disease, with multiple-organ failure (MOF) manifestations such as shock, respiratory failure, disseminated intravascular coagulation (DIC) and death, but cases of SFTS patients with central nervous system (CNS) symptoms onset and marked persistent involuntary shaking of the perioral area and limbs have rarely been reported.

CASE PRESENTATION

A 69-year-old woman with fever and persistent involuntary shaking of the perioral area and limbs was diagnosed with SFTS with CNS symptom onset after metagenomic next-generation sequencing (mNGS) of cerebrospinal fluid (CSF) and peripheral blood identified SFTSV. The patient developed a cytokine storm and MOF during the course of the disease, and after aggressive antiviral, glucocorticoid, and gamma globulin treatments, her clinical symptoms improved, her laboratory indices returned to normal, and she had a good prognosis.

CONCLUSION

This case gives us great insight that when patients with CNS symptoms similar to those of viral encephalitis combined with thrombocytopenia and leukopenia are encountered in the clinic, it is necessary to consider the possibility of SFTS involving the CNS. Testing for SFTSV nucleic acid in CSF and blood (mNGS or polymerase chain reaction (PCR)) should be carried out, especially in critically ill patients, and treatment should be given accordingly.

Hemophagocytic syndrome related by EBV infection: case report

A 34-year-old woman of Asian origin with diffuse lymphadenopathy and hepatosplenomegaly in hemophagocytic syndrome induced by Epstein Barr Virus (EBV) infection. The rapidity of progression of clinical manifestations lead to early orotracheal intubation and death due to multiple organ failure (MOF).

Dengue-Associated Hemophagocytic Lymphohistiocytosis: A Narrative Review of Its Identification and Treatment

Dengue's lack of specific treatments beyond supportive care prompts a focus on uncovering additional pathophysiological factors. Dengue-associated hemophagocytic lymphohistiocytosis (HLH), characterized by dysregulated macrophage activation and cytokine storm, remains underexplored despite its potential to worsen disease severity and mortality. While rare, dengue-associated HLH disproportionately affects severe cases, significantly impacting mortality rates. To mitigate high mortality, early identification and familiarity with dengue-associated HLH are imperative for prompt treatment by clinicians. This narrative review therefore aims to examine the current clinical and therapeutic knowledge on dengue-associated HLH, and act as a resource for clinicians to improve their management of HLH associated with severe dengue. Dengue-associated HLH should be considered for all cases of severe dengue and may be suspected based on the presence of prolonged or recurrent fever for >7 days, or anemia without intravascular hemolysis or massive bleeding. Diagnosis relies on fulfilling at least five of the eight HLH-2004 criteria. Treatment predominantly involves short courses (3-4 days) of high-dose steroids (e.g., dexamethasone 10 mg/m2), with additional therapies considered in more severe presentations. Notably, outcomes can be favorable with steroid therapy alone.

Persistent Fever after COVID-19 Vaccination in a Patient with Ulcerative Colitis: A Call for Attention

The development of vaccinations has been game-changing in the ongoing effort to combat the COVID-19 pandemic. Until now, adverse effects are being reported at low frequency, including thrombocytopenia and myocarditis. Careful monitoring for any suspicious symptoms and signs following vaccination is necessary. We report a case of hemophagocytic lymphohistiocytosis (HLH) after mRNA COVID-19 vaccine in a 23-year-old female with ulcerative colitis. Diagnosis was made according to HLH-2004 criteria and the patient was treated with dexamethasone with response. Our report aimed to draw attention to the potential relation between COVID-19 vaccines and HLH and the necessity of continued surveillance, especially in at-risk populations such as those with underlying immune dysregulation.

Association of a decreased platelet count with poor survival in patients with adult secondary hemophagocytic lymphohistiocytosis

We aimed to examine the association between baseline platelet count (PLT) and the prognosis of adult secondary hemophagocytic lymphohistiocytosis (sHLH). Data from 292 patients with pretreatment platelet counts were retrospectively analysed from January 2016 to December 2020. We categorized platelet count into quartiles. Multivariable Cox proportional hazards models and restricted cubic splines (RCS) were used to evaluate the relationship between platelet count and mortality. During a median follow-up of 53 (interquartile ranges, 17-223) days, a total of 208 deaths occurred. After adjusting for multiple variables, a non-linear and inverse relationship was observed between platelet count and mortality in sHLH patient (P for nonlinearity=0.002). For non- lymphoma-associated haemophagocytic lymphohistiocytosis (non-LHLH), a similar curve was also observed (P for nonlinearity =0.028). Decreased PLT (PLT Q4) was associated with an increased risk of mortality (adjusted hazard ratio: 1.97; 95% confidence interval: 1.28-3.04; Ptrend =0.005). Similar results were observed in the LHLH subgroup (adjusted hazard ratio: 1.84; 95% confidence interval: 1.05-3.24; Ptrend =0.024) but not in the non-LHLH subgroup (Ptrend =0.266). Baseline platelet count demonstrated a nonlinear and inverse association with an increased risk of mortality among adult sHLH patients. This method is used to identify sHLH patients with inferior overall survival due to its low cost and universal availability.

Important Considerations in the Intensive Care Management of Acute Leukemias

In the realm of hematologic disorders, acute leukemia is approached as an emergent disease given the multitude of complications and challenges that present both as a result of inherent disease pathology and adverse events associated with antineoplastic therapies and interventions. The heavy burden of leukemic cells may lead to complications including tumor lysis syndrome, hyperleukocytosis, leukostasis, and differentiation syndrome, and the initiation of treatment can further exacerbate these effects. Capillary leak syndrome is observed as a result of antineoplastic agents used in acute leukemia, and L-asparaginase, a bacterial-derived enzyme, has a unique side effect profile including association with thrombosis. Thrombohemorrhagic syndrome and malignancy-associated thrombosis are also commonly observed complications due to direct disequilibrium in coagulant and anticoagulant factors. Due to inherent effects on the white blood cell milieu, leukemia patients are inherently immunocompromised and vulnerable to life-threatening sepsis. Lastly, the advents of newer therapies such as chimeric antigen receptor (CAR) T-cells have clinicians facing the management of related toxicities on unfamiliar territory. This review aims to discuss these acute leukemia-associated complications, their pathology, and management recommendations.

Hemophagocytic lymphohistiocytosis after solid organ transplantation: A challenge for clinicians

Hemophagocytic lymphohistiocytosis (HLH) is a rare inflammatory disorder with a high mortality rate and a wide range of symptoms. Solid organ transplantation, which provides patients with a unique immunosuppressive state, is a less common predisposing factor for HLH. HLH after solid organ transplantation (HLH-SOT) is very rare and fatal. It is hard to diagnose and treat and extremely understudied. The use of immunosuppressants makes the situation of HLH-SOT more complex. This review summarizes the existing literature on HLH after solid organ transplantation and describes its triggers and symptoms, focusing on its diagnosis and treatment. We performed a literature search of case reports, case series, letters to the editor, and clinical quizzes describing patients with HLH after solid organ transplantation (HLH-SOT). We provide recommendations on the diagnosis protocol and treatment strategy based on the existing evidence.

CLINICAL UTILITY OF INTERLEUKIN-1 INHIBITORS IN PEDIATRIC SEPSIS

ABSTRACT

The pathophysiology of pediatric sepsis is characterized by increased innate immune activation earlier in life. Interleukin-1 is a proinflammatory cytokine implicated in the pathophysiology of sepsis, and ferritin is a stable surrogate biomarker for elevated IL-1 levels. Data in adult sepsis have shown that use of anakinra, an anti-IL-1 receptor antagonist, led to improved clinical outcomes in patients with features of macrophage activation and hyperferritinemia. However, data in pediatric sepsis are lacking. Our narrative review sought to highlight the current understanding of using IL-1 inhibitors in pediatric sepsis. We identified five studies including one case report and four retrospective case series that described clinical outcomes in relation to use of anakinra for secondary hemophagocytic lymphohistiocytosis (HLH). A few patients in this pooled heterogenous cohort of 72 patients had concomitant infection meeting the criteria for sepsis. All studies measured ferritin levels and reported a decrease in ferritin after initiating anakinra. Twelve patients died after treatment initiation. There was no clear comparison in clinical outcomes between infected and noninfected patients. The pathophysiology of pediatric sepsis suggests that there is a need for blinded clinical trials using targeted immunomodulation such as IL-1 inhibitors in pediatric sepsis cohort with an immunophenotype suggesting increased innate immune activation.

Prognostic Factors of Adult Hemophagocytic Lymphohistiocytosis and Clinical Utility of HLH-2004 Diagnostic Criteria and HScore: A Real-World Multicenter Study from Thailand

INTRODUCTION

Adult hemophagocytic lymphohistiocytosis (HLH) is a rare disease with a dismal prognosis. Early diagnosis and prompt management are necessary for improved outcomes.

METHODS

This multicenter retrospective study investigated the etiologies, survival, and prognostic factors of HLH, including the utility of HLH-2004 criteria and HScore in real-life clinical practice.

RESULTS

A total of 147 HLH patients were identified by using a combination of hemophagocytosis identification in bone marrow and the HLH-related international classification disease-10. A total of 116 (78.9%) patients fulfilled the HLH diagnosis by HScore, while 91 (61.9%) patients fulfilled 5 of 8 HLH-2004 criteria. In Thailand, the clinical application of HLH-2004 criteria needed to be reduced from 8 to 6 due to a lack of sCD25 and natural killer cell activity tests. Using the adapted HLH-2004 with a cutoff value of 4 resulted in 132 (89.9%) cases meeting the diagnostic criteria. Among these 132 confirmed HLH patients by using adapted HLH-2004, HLH was triggered by infection (29.5%), autoimmune disease (12.9%), malignancy (40.9%), and unknown cause (16.7%). Median overall survival of HLH patients was extremely short (67 days). Ferritin >6,000 μg/L, HLH from infection, malignancy, and unknown etiology were demonstrated as independent prognostic factors for inferior survival (hazard ratio [HR] 2.47; 95% confidence interval [CI] 1.39-4.37, HR 4.69; 95% CI 1.38-15.92, HR 6.09; 95% CI 1.84-20.14, and HR 6.02; 95% CI 1.64-22.05, respectively).

CONCLUSION

Ferritin is a helpful biomarker for HLH diagnosis and prognostic prediction. Autoimmune disease-triggered HLH has favorable outcomes. Future prospective study is required to verify the use of the adapted HLH-2004 criteria.

Criteria for Cytokine Storm Syndromes

In the past two decades, there has been a great deal of work aimed to devise diagnostic guidelines, classification criteria, and diagnostic scores for cytokine storm syndromes (CSSs). The most notable effort has been the large-scale multinational study that led to the development of the 2016 classification criteria for macrophage activation syndrome (MAS) complicating systemic juvenile idiopathic arthritis (JIA). Future studies should scrutinize the validity of the proposed criteria, particularly in systemic JIA patients treated with biologics, in children with subtle or incomplete forms of MAS, and in patients with MAS complicating other rheumatologic disorders. More generic CSS criteria are also available but often lack sensitivity and specificity in a wide variety of patient populations and CSSs of different etiologies. The coronavirus disease 2019 (COVID-19)-related lung disease led to an evolution of the concept of a "cytokine storm." Emerging and unsolved challenges in the diagnosis of the different forms of CSSs highlight the need for diagnostic tools and well-established classification criteria to enable timely recognition and correct classification of patients.

Diagnosis and investigation of suspected haemophagocytic lymphohistiocytosis in adults: 2023 Hyperinflammation and HLH Across Speciality Collaboration (HiHASC) consensus guideline

Haemophagocytic lymphohistiocytosis (HLH) is a hyperinflammatory syndrome characterised by persistently activated cytotoxic lymphocytes and macrophages, which, if untreated, leads to multiorgan dysfunction and death. HLH should be considered in any acutely unwell patient not responding to treatment as expected, with prompt assessment to look for what we term the three Fs-fever, falling blood counts, and raised ferritin. Worldwide, awareness of HLH and access to expert management remain inequitable. Terminology is not standardised, classification criteria are validated in specific patient groups only, and some guidelines rely on specialised and somewhat inaccessible tests. The consensus guideline described in this Health Policy was produced by a self-nominated working group from the UK network Hyperinflammation and HLH Across Speciality Collaboration (HiHASC), a multidisciplinary group of clinicians experienced in managing people with HLH. Combining literature review and experience gained from looking after patients with HLH, it provides a practical, structured approach for all health-care teams managing adult (>16 years) patients with possible HLH. The focus is on early recognition and diagnosis of HLH and parallel identification of the underlying cause. To ensure wide applicability, the use of inexpensive, readily available tests is prioritised, but the role of specialist investigations and their interpretation is also addressed.

Hemophagocytic Lymphohistiocytosis in the Context of Hematological Malignancies and Solid Tumors

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

Etoposide Therapy of Cytokine Storm Syndromes

Etoposide has revolutionized the treatment of primary as well as secondary hemophagocytic lymphohistiocytosis (HLH), and it is, together with corticosteroids, the most widely used therapy for HLH. In the early 1980s, long-term survival in primary HLH was <5% but with the etoposide-/dexamethasone-based protocols HLH-94 and HLH-2004, in combination with stem cell transplantation, 5-year survival increased dramatically to around 60% in primary HLH, and based on analyses from the HLH-2004 study, there is likely room for further improvement. Biologically, etoposide administration results in potent selective deletion of activated T cells as well as efficient suppression of inflammatory cytokine production. Moreover, etoposide has also been reported to promote programmed cell death (apoptosis) rather than proinflammatory lytic cell death (pyroptosis), conceivably ameliorating subsequent systemic inflammation, i.e., a treatment very suitable for cytokine storm syndromes (CSS). The combination of etoposide and corticosteroids may also be beneficial in cases of severe or refractory secondary HLH (sHLH) with imminent organ failure, such as infection-associated HLH caused by Epstein-Barr virus (EBV) or malignancy-triggered HLH. In CSS associated with rheumatic diseases (macrophage activation syndrome, MAS or MAS-HLH), etoposide is currently used as second- or third-line therapy. Recent studies suggest that etoposide perhaps should be part of an aggressive therapeutic intervention for patients with severe refractory or relapsing MAS, in particular if there is CNS involvement. Importantly, awareness of sHLH must be further increased since treatment of sHLH is often delayed, thereby missing the window of opportunity for a timely, effective, and potentially life-saving HLH-directed treatment.

Severe adult hemophagocytic lymphohistiocytosis (HLHa) correlates with HLH-related gene variants

BACKGROUND

The contribution of genetic factors to the severity of adult hemophagocytic lymphohistiocytosis (HLHa) remains unclear.

OBJECTIVE

We sought to assess a potential link between HLHa outcomes and HLH-related gene variants.

METHODS

Clinical characteristics of 130 HLHa patients (age ≥ 18 years and HScore ≥ 169) and genotype of 8 HLH-related genes (LYST, PRF1, UNC13-D, STX11, STXBP2, RAB27A, XIAP, and SAP) were collected. A total of 34 variants found in only 6 genes were selected on the basis of their frequency and criteria predicted to impair protein function. Severity was defined by refractory disease to HLH treatment, death, or transfer to an intensive care unit.

RESULTS

HLHa-associated diseases (ADs) were neoplasia (n = 49 [37.7%]), autoimmune/inflammatory disease (n = 33 [25.4%]), or idiopathic when no AD was identified (n = 48 [36.9%]). Infectious events occurred in 76 (58.5%) patients and were equally distributed in all ADs. Severe and refractory HLHa were observed in 80 (61.5%) and 64 (49.2%) patients, respectively. HScore, age, sex ratio, AD, and infectious events showed no significant association with HLHa severity. Variants were identified in 71 alleles and were present in 56 (43.1%) patients. They were distributed as follows: 44 (34.4%), 9 (6.9%), and 3 (2.3%) patients carrying 1, 2, and 3 variant alleles, respectively. In a logistic regression model, only the number of variants was significantly associated with HLHa severity (1 vs 0: 3.86 [1.73-9.14], P = .0008; 2-3 vs 0: 29.4 [3.62-3810], P = .0002) and refractoriness (1 vs 0: 2.47 [1.17-5.34], P = .018; 2-3 vs 0: 13.2 [2.91-126.8], P = .0003).

CONCLUSIONS

HLH-related gene variants may be key components to the severity and refractoriness of HLHa.

Hemophagocytic lymphohistiocytosis with jaundice as first manifestation: A case report

BACKGROUND

Hemophagocytic lymphohistiocytosis (HLH) is a rare but life-threatening condition. It is an immune-mediated disease that has a wide range of causes, elicits a hyperinflammatory response, and results in multiple organ damage. Clinical presentations vary, and in some cases, jaundice occurs as the first symptom.

CASE SUMMARY

We report the case of a 71-year-old female patient who presented with jaundice. She was admitted to our hospital because of the occurrence of "jaundice for half a month", and upon examination, obstructive jaundice with choledocholithiasis and gallstones was suggested. Cholecystectomy and choledocholithotomy were performed. However, the jaundice did not improve after surgery. We found splenomegaly, cytopenia, hypertriglyceridemia, hypofibrinogenemia, and elevated ferritin. Bone marrow biopsy revealed hemophagocytosis. Later, cardiac arrest occurred when she returned 3 wk after the surgery. We considered that HLH was triggered by septic shock. The patient's condition deteriorated rapidly, with multiple organ dysfunction and severe gastrointestinal bleeding. Corticosteroid therapy and symptomatic treatment failed to save her life.

CONCLUSION

Jaundice rarely presents as the first symptom in HLH patients. The HLH in this case was triggered by septic shock with jaundice as the first symptom. Clinicians should try hard to reduce missed diagnoses and misdiagnoses.

Clinical characteristics, treatment, and management of pembrolizumab induced hemophagocytic lymphohistiocytosis

BACKGROUND

Hemophagocytic lymphohistiocytosis (HLH) is a rare and fatal adverse reaction to pembrolizumab. The clinical characteristics of pembrolizumab induced HLH are unknown. Exploring the clinical features of pembrolizumab induced HLH is crucial for the treatment and prevention of immune checkpoint inhibitor-induced HLH.

METHODS

The literature related to pembrolizumab induced HLH was collected for retrospective analysis by searching the Chinese and English databases from inception until August 31, 2023.

RESULTS

A total of 24 patients were included, including 17 men (70.8%) with a median age of 61 years (41,80). The time between the last infusion and the start of HLH ranged from 2 to 46 days, with a median time of 14 days. Fever (100%) was the most common symptom, accompanied by splenomegaly (14 cases, 58.3%) and hepatomegaly (6 cases, 25.0%). Laboratory examination revealed revealed anemia (18 cases, 75.0%), leukopenia (12 cases, 50.0%), thrombocytopenia (20 cases, 83.3%), hypertriglyceridemia (11 cases, 45.8%), hypofibrinogenemia (11 cases, 45.8%). decreased natural killer cell function (7 cases, 29.2%), and elevated soluble CD25(15 cases, 62.5%). All patients developed hyperferriinemia, with a median of 30,808 ng/mL (range 1303 ~ 100,000). Bone marrow biopsy showed hemophagocytosis (15 cases, 62.5%). After discontinuation of pembrolizumab and treatment with steroids, etoposide, intravenous immunoglobulin, cytokine blocking, and immunosuppression, 17 patients recovered or improved, and 5 patients eventually died.

CONCLUSION

HLH should be suspected when unexplained fever, cytopenia, splenomegaly, and elevated aminotransferase occur in patients using pembrolizumab. Screening for risk factors before treatment with pembrolizumab may be necessary to prevent HLH.

Late-onset Familial Hemophagocytic Lymphohistiocytosis in a survivor of Hodgkin's Lymphoma

Hemophagocytic Lymphohistiocytosis is an inflammatory condition which results in over activation of the immune system. It could be either sporadic or familial. The familial subtype is linked with various genetic mutations and is commonly a disease of the young. Here we report a case of HLH in an adult, occurring in the background of a successfully treated hematological malignancy. Upon workup, he was also found to have pathogenic STXBP2 mutation, suggesting HLH of familial origin. To date, only few cases of adult-onset familial HLH have been brought to light.

Small cell carcinoma of the kidney treated with immune checkpoint inhibitor/tyrosine kinase inhibitor

Introduction

Small cell carcinoma (SCC) of the kidney is extremely rare. Although the majority of patients with advanced renal small cell carcinoma were treated with a combination of cisplatin and etoposide, the efficacy was limited. We report the first case with renal small cell carcinoma who received nivolumab and cabozantinib.

Case presentation

A 57-year-old woman was referred to our hospital with a massive left kidney mass and several bone, lymph nodes, liver, and lung metastases. A left renal mass biopsy made the diagnosis of small cell carcinoma. Nivolumab and cabozantinib were used in combination therapy. The tumors were stable during the treatment for 4 weeks. However, the treatment was halted due to a serious adverse event, immune-related hemophagocytic lymphohistiocytosis. Although immune-related hemophagocytic lymphohistiocytosis was resolved with corticosteroids, the patient died 3 months after the initiation of nivolumab and cabozantinib.

Conclusion

We reported the first case of renal small cell carcinoma treated with nivolumab and cabozantinib.

Delay in treatment of adult hemophagocytic lymphohistiocytosis is associated with worse in-hospital outcomes

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening condition characterized by uncontrolled activation of the immune system leading to multiorgan failure. Timely initiation of HLH-specific treatment is believed to be essential and lifesaving. Due to the rarity of the condition in adults, there is no data available in the literature to investigate the effects of treatment delay in this age group. We used data from the National Inpatient Sample (NIS) to evaluate the inpatient practices of HLH treatment initiation over 13 years (2007-2019) and their association with clinically relevant inpatient outcomes. Patients were divided into early treatment group (<6 days) and late treatment group (≥ 6 days). We compared outcomes using multivariate logistic regression models adjusting for age, sex, race, and HLH-triggering conditions. There were 1327 and 1382 hospitalizations in the early and late treatment groups, respectively. Hospitalization in the late treatment group had higher rates of in-hospital mortality (OR 2.00 [1.65-2.43]), circulatory shock (OR 1.33 [1.09-1.63]), requiring mechanical ventilation (OR 1.41 [1.18-1.69]), venous thromboembolism (OR 1.70 [1.27-2.26]), infectious complications (OR 2.24 [1.90-2.64]), acute kidney injury (OR 2.27 [1.92-2.68]), and requiring new hemodialysis (OR 1.45 [1.17-1.81]). Additionally, we observed no significant trend in the mean time to treatment over the study period. This study shows the importance of early initiation of HLH treatment and highlights the adverse outcomes of treatment delay.

Postpartum hemophagocytic lymphohistiocytosis: A case report

BACKGROUND

Postpartum hemophagocytic lymphohistiocytosis (HLH) is a rare disease with unclear pathophysiology. It is a secondary HLH diagnosed using the pediatric diagnostic criteria; however, the clinical diagnosis of postpartum HLH remains challenging. Hence, HLH may remain undiagnosed, leading to poor patient prognosis. Therefore, improvements in the accuracy of postpartum HLH diagnoses and treatments are necessary.

CASE SUMMARY

We report the case of a 40-year-old female with postpartum HLH. The patient attended the postpartum care center for 3 wk after giving birth and underwent needle aspiration due to thyroid gland enlargement 11 d before an emergency department visit precipitated by fever and abdominal pain. Since no abnormal emergency room findings were noted, the patient was discharged with a prescription for broad-spectrum antibiotics. Three days later, she returned to the emergency room in a hemodynamically unstable state and was admitted to the intensive care unit with suspected sepsis or hematologic disease. The patient was treated, without effect, for sepsis using broad-spectrum antibiotics, and for suspected hematologic disease with steroid therapy. However, she died due to rapidly worsening symptoms.

CONCLUSION

Rapid recognition and appropriate treatment of postpartum HLH are needed to improve the prognosis.

Prolonged Fever in a Pediatric Patient: A Case of Systemic Juvenile Idiopathic Arthritis (sJIA) Complicated by Macrophage Activation Syndrome (MAS)

A prolonged fever in a child can be due to a range of causes including infectious, autoimmune, malignant, or genetic in etiology. In our report, we present the case of a previously healthy three-year-old female diagnosed with macrophage activation syndrome (MAS) due to complications of systemic juvenile arthritis (sJIA). MAS is considered a secondary subtype of hemophagocytic lymphohistiocytosis (HLH), a rare and life-threatening group of syndromes characterized by overstimulation of the immune system leading to systemic inflammation. Through our case, we wanted to bring awareness to this uncommon group of diseases as well as discuss the importance of differentiating between its subtypes. While HLH and MAS have similar clinical presentations, the treatment regimen for each is distinct. Moreover, further research should be conducted to create standardized criteria and treatment guidelines that are evidence-based in order to properly manage these patients.

The predictive value of hematological inflammatory markers for acute kidney injury and mortality in adults with hemophagocytic Lymphohistiocytosis: A retrospective analysis of 585 patients

BACKGROUND

Hemophagocytic lymphohistiocytosis (HLH) is a rare immunological hyperactivation-related disease with a high mortality rate. The purpose of this study was to examine the relationship between complete blood count parameters and the occurrence of acute kidney injury (AKI) and mortality in patients with HLH.

METHODS

We included 585 adult patients with HLH. Logistic regression models for AKI and 28-day mortality were developed.

RESULTS

Multivariate logistic regression models revealed that hemoglobin (HB) ≤ 7.3 g/dl (adjusted OR, 1.651; 95% CI, 1.044-2.612), hemoglobin-to-red blood cell distribution width ratio (HRR) < 0.49 (adjusted OR, 1.692), neutrophil-to-lymphocyte ratio (NLR) ≥ 3.15 (adjusted OR, 1.697), and neutrophil-to-lymphocyte-platelet ratio (NLPR) ≥ 11.0 (adjusted OR, 1.608) were independent risk factors for the development of AKI. Moreover, lower platelet levels (31 × 109/L < platelets < 84 × 109/L, adjusted OR, 2.133; platelets ≤ 31 × 109/L, adjusted OR, 3.545) and higher red blood cell distribution width-to-platelet ratio (RPR) levels (0.20 < RPR < 0.54, adjusted OR, 2.595; RPR ≥ 0.54, adjusted OR, 4.307), lymphocytes ≤ 0.34 × 109/L (adjusted OR, 1.793), NLPR ≥ 11.0 (adjusted OR, 2.898), and the aggregate index of systemic inflammation (AISI) ≤ 7 (adjusted OR,1.778) were also independent risk factors for 28-day mortality. Furthermore, patients with AKI had a worse prognosis than those without AKI (P < 0.05).

CONCLUSION

In patients with HLH, hematological parameters are of great value for the early identification of patients at high risk of AKI and 28-day mortality.