Clinical characterization of hemophagocytic lymphohistiocytosis caused by immune checkpoint inhibitors: a review of published cases.

OBJECTIVE: An association exists between immune checkpoint inhibitors and hemophagocytic lymphohistiocytosis (HLH). Therefore, the main objective of this study was to collect data on this rare but potentially life-threatening immune-related adverse reaction to identify the medications that cause it, the clinical characteristics, and effective treatments. METHODS: Literature in English and Chinese on immune checkpoint inhibitors causing HLH published from August 2014 to March 2024 was analyzed. Immune checkpoint inhibitors, immunotherapy, anti-PD-1, PD-L1 inhibitors, HLH, hemophagocytic lymphohistiocytosis, hemophagocytic syndrome keywords were used to find the literature on China Knowledge Network, Wanfang, PubMed and Emabase Databases. RESULTS AND DISCUSSION: Twenty-four studies were included, with a total of 27 patients (18 males and 9 females) with a mean age of 58 years (range 26-86). The mean time to the onset of symptoms was 10.3 weeks (7 days-14 months). The main clinical characteristics were fever, cytopenia, splenomegaly, methemoglobinemia, hypofibrinogenemia, and bone marrow biopsy showed phagocytosis. Twenty-two patients improved after the treatment with steroids, cytokine blocking therapy and symptomatic treatment, four patients died, and one patient was not described. CONCLUSION: HLH should be not underestimated as a potentially serious adverse effect of immune checkpoint inhibitors since appropriate treatments may save the life of patients.

Differential effects of itacitinib, fedratinib, and ruxolitinib in mouse models of hemophagocytic lymphohistiocytosis.

ABSTRACT: Hemophagocytic lymphohistiocytosis (HLH) comprises a severe hyperinflammatory phenotype driven by the overproduction of cytokines, many of which signal via the JAK/STAT pathway. Indeed, the JAK1/2 inhibitor ruxolitinib has demonstrated efficacy in preclinical studies and early-phase clinical trials in HLH. Nevertheless, concerns remain for ruxolitinib-induced cytopenias, which are postulated to result from the blockade of JAK2-dependent hematopoietic growth factors. To explore the therapeutic effects of selective JAK inhibition in mouse models of HLH, we carried out studies incorporating the JAK1 inhibitor itacitinib, JAK2 inhibitor fedratinib, and JAK1/2 inhibitor ruxolitinib. All 3 drugs were well-tolerated and at the doses tested, they suppressed interferon-gamma (IFN-γ)-induced STAT1 phosphorylation in vitro and in vivo. Itacitinib, but not fedratinib, significantly improved survival and clinical scores in CpG-induced secondary HLH. Conversely, in primary HLH, in which perforin-deficient (Prf1-/-) mice are infected with lymphocytic choriomeningitis virus (LCMV), itacitinib, and fedratinib performed suboptimally. Ruxolitinib demonstrated excellent clinical efficacy in both HLH models. RNA-sequencing of splenocytes from LCMV-infected Prf1-/- mice revealed that itacitinib targeted inflammatory and metabolic pathway genes in CD8 T cells, whereas fedratinib targeted genes regulating cell proliferation and metabolism. In monocytes, neither drug conferred major transcriptional impacts. Consistent with its superior clinical effects, ruxolitinib exerted the greatest transcriptional changes in CD8 T cells and monocytes, targeting more genes across several biologic pathways, most notably JAK-dependent proinflammatory signaling. We conclude that JAK1 inhibition is sufficient to curtail CpG-induced disease, but combined inhibition of JAK1 and JAK2 is needed to best control LCMV-induced immunopathology.

Lamotrigine-Induced Hemophagocytic Lymphohistiocytosis with DRESS.

BACKGROUND: Hemophagocytic lymphohistiocytosis (HLH) is a severe inflammatory reaction syndrome caused by genetic or acquired immune dysregulation. The majority of adult HLH cases are caused by tumors, rheumatic immune disorders, and infections. However, drug-induced HLH is rarely reported. METHODS: We report a case of HLH in an adult caused by the administration of lamotrigine, to our knowledge, only nine other cases of lamotrigine-associated HLH have been reported in adult patients. RESULTS: After discontinuing lamotrigine and using steroid hormones for the HLH, the patient's condition has been brought under control. CONCLUSIONS: This case confirms that dexamethasone is also effective for drug-induced HLH. Usually, after discontinuing the relevant medications, there is no need for further maintenance treatment.

Hemophagocytic lymphohistiocytosis following pembrolizumab and bevacizumab combination therapy for cervical cancer: a case report and systematic review.

BACKGROUND: Programmed cell death protein 1 (PD-1) checkpoint inhibitors such as pembrolizumab are novel therapeutics used to treat various advanced malignancies. Immune-related adverse events are common, among the most serious of these toxicities is hemophagocytic lymphohistiocytosis (HLH), which is a life-threatening disorder of unbridled immune activation but has not been properly established. METHODS: We have procured the first case of hemophagocytic lymphohistiocytosis as an aftermath of treatment with pembrolizumab from the Sir Run Run Shaw Hospital, Zhejiang University, China. In a pursuit to enhance the understanding of this condition, a comprehensive systematic review was performed encompassing all reported instances of ICI-associated Hemophagocytic lymphohistiocytosis within the realms of PubMed and Embase databases. RESULTS: We detail the recovery of a cervical cancer patient with a history of psoriasis who developed HLH after combined pembrolizumab and bevacizumab treatment. Remarkably, tumor lesions exhibited substantial and sustained regression. From an analysis of 52 identified Immune Checkpoint Inhibitor (ICI)-related HLH cases, we discovered that HLH often occurred within the first two treatment cycles and approximately 20% of these patients had a history of autoimmune-related diseases. Despite a 15% mortality rate, the majority of patients experienced positive outcomes. Notably, in instances of recovery from HLH, 80% showed positive tumor outcomes. Even after discontinuation of ICI treatment, tumor control persisted in some cases. CONCLUSION: We identified the first case of HLH caused by ICI treatment in cervical cancer and summarized the possible occurrence factors of these cases, the treatment outcomes of HLH, and the impact on tumor outcomes.

Hemophagocytic lymphohistiocytosis induced by nivolumab/ipilimumab combination therapy: A case of lung adenocarcinoma that responded to early steroid pulse therapy.

BACKGROUND: Immune checkpoint inhibitors have been reported to have excellent therapeutic effects on various malignant tumors. However, immune-related adverse events can occur, targeting various organs. CASE PRESENTATION: A 49-year-old male with lung carcinoma was started on carboplatin + pemetrexed + nivolumab (every 3 weeks) + ipilimumab (every 6 weeks), and nivolumab/ipilimumab was administered in the 3rd course. Subsequently, fever and fatigue developed, and grade 3 liver damage was also noted, so he was admitted to Kindai University Hospital. A bone marrow aspirate examination was performed on the third day of illness, and a definitive diagnosis of hemophagocytic lymphohistiocytosis (HLH) was made. It was determined that immediate therapeutic intervention was necessary, and pulse therapy with methylprednisolone was started on the third day of illness. After 3 days of pulse treatment, a rapid recovery of platelet values, a decrease in ferritin levels, and a decrease in lactate dehydrogenase were observed. Subjective symptoms such as fever and fatigue also quickly improved. CONCLUSION: Early diagnosis and treatment for HLH resulted in a positive response. The number of HLH cases may increase in the future due to the expansion of immune checkpoint inhibitor indications.

Exposure-safety relationship for patients with primary hemophagocytic lymphohistiocytosis treated with emapalumab.

Primary hemophagocytic lymphohistiocytosis (pHLH) is an immune-mediated, hyperinflammatory disorder. Interferon-γ (IFNγ) plays a key role in the pathophysiology of pHLH. Emapalumab, a fully human, anti-IFNγ monoclonal antibody neutralizes both free and receptor-bound IFNγ. However, inhibiting IFNγ-mediated signaling could result in immune dysfunction and immunosuppression. This exploratory exposure-safety analysis investigated the relationship between emapalumab and the incidence of adverse events in patients with pHLH. Increased exposure to emapalumab was not associated with an increased predicted risk of severe adverse events, infection, or infusion-related reactions. Emapalumab was associated with a favorable and manageable safety profile across all assessed doses and treatment durations.

Filgrastim-induced hemophagocytic lymphohistiocytosis in a patient with mantle cell lymphoma: A case report.

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening disease potentially induced by various causes. Very few reports have described HLH induced by granulocyte colony-stimulating factor (G-CSF) and those few previous reports have uniformly indicated that continuing G-CSF is unfeasible once HLH has been induced. A 52-year-old Japanese man who had been diagnosed with mantle cell lymphoma with systemic and central nervous system involvements received rituximab, hyper-fractionated cyclophosphamide, vincristine, Adriamycin and dexamethasone (R-HCVAD)/methotrexate and cytarabine. During the second cycle of R-HCVAD, the patient developed severe back pain, thrombocytopenia, elevated serum lactate dehydrogenase and ferritin levels, and hemophagocytosis in the bone marrow. Complete remission (CR) of mantle cell lymphoma was confirmed on whole-body computed tomography, brain magnetic resonance imaging, and bone marrow biopsy. The patient was diagnosed with HLH induced by filgrastim. HLH recovered with intravenous methylprednisolone at 1 g/day for 3 days, followed by oral prednisolone tapered off over 5 days. The patient continued chemotherapy with a change in the G-CSF formulation from filgrastim to lenograstim and prophylactic administration of corticosteroids. He safely completed scheduled chemotherapy without recurrence of HLH and successfully maintained CR of lymphoma. Although rare, G-CSF potentially induces HLH. Changing the G-CSF formulation and steroid prophylaxis may allow safe continuation of G-CSF.

Drug-induced secondary haemophagocytic lymphohistiocytosis in hairy cell leukaemia.

Haemophagocytic lymphohistiocytosis (HLH) is a rare, aggressive, excess immune activation syndrome. Diagnosis can be challenging due to its several clinical mimics including sepsis. There are multiple aetiologies of HLH; in adults, it is most commonly triggered by infection, malignancy, drugs and autoimmune processes. Failure to rapidly diagnose and treat this condition can be fatal. The management of HLH includes identifying and removing the trigger, supportive management and immunosuppression. Identifying the trigger is essential to inform the most appropriate type of immunosuppression. Here, we report a case of likely drug-induced HLH in a patient recently treated for hairy cell leukaemia. The culprit drug was thought to be co-trimoxazole and this case report highlights a very rare complication of this commonly used drug. We discuss our management approach with steroid monotherapy and withdrawal of co-trimoxazole.

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.

Auto-immune hemolytic anemia and hemophagocytic lymphohistiocytosis as immune-related adverse event in patients with metastatic melanoma and concurrent chronic lymphocytic leukemia: a case series and literature review.

Auto-immune hemolytic anemia (AIHA) and hemophagocytic lymphohistiocytosis (HLH) are both rare immune-related adverse events (irAEs) following treatment with immune checkpoint inhibitors. Consensus treatment guidelines are currently lacking. Patients with a solid malignancy and a concurrent lymphoproliferative disorder, such as chronic lymphocytic leukemia (CLL), might be more prone to develop hematological irAEs. We report the case history of two patients, diagnosed with CLL, who during treatment for metastatic melanoma with nivolumab, a PD-1 immune checkpoint blocking mAb, developed AIHA and HLH in combination with AIHA. Furthermore, we provide a review of the literature on published cases of immune-related AIHA and HLH and their correlation with CLL.

An unforeseen reality: Hemophagocytic lymphohistiocytosis following alemtuzumab treatment for a multiple sclerosis.

Alemtuzumab is a humanized monoclonal antibody indicated for treatment of highly active relapsing-remitting multiple sclerosis (HA-RRMS). It binds to CD52 antigen and produces a rapid and prolonged lymphocyte depletion followed by a different pattern of T and B cell repopulation. Among others, its adverse events are autoimmune diseases.In this article, we present a patient with HA-RRMS, who was subsequently treated with alemtuzumab and afterwards developed hemophagocytic lymphohistiocytosis (HLH). Albeit rarely, HLH can be triggered by alemtuzumab treatment.HLH can favourably respond to prompt immunosuppressant therapy.Multidisciplinary approach by a team consisting of a neurology, hematology and rheumatology specialist is needed to treat this potentially lethal condition.

Haemophagocytic lymphohistiocytosis (HLH) in an adult following treatment with trimethoprim/sulfamethoxazole.

Haemophagocytic lymphohistiocytosis (HLH) is an aggressive hyperinflammatory haematological condition often associated with malignancy, infection or rheumatological disorders. HLH has rarely been associated with medications, including antibiotics. We describe a case of a patient without significant medical history who presented with HLH following treatment with trimethoprim/sulfamethoxazole (TMP/SMX). Additionally, we will discuss the possible mechanism of medication-induced HLH as well as the successful use of dexamethasone as the sole treatment. Early diagnosis and treatment of this disease is critical and medication-induced HLH should be considered in cases without a clear aetiology. To our knowledge, this is the first case report of TMP/SMX-induced HLH that was successfully treated with steroid monotherapy and just the second case report of TMP/SMX-induced HLH.

A case of hemophagocytic lymphohistiocytosis after BNT162b2 COVID-19 (Comirnaty®) vaccination.

RATIONALE: Coronavirus disease (COVID-19), an infectious disease caused by the severe acute respiratory syndrome coronavirus 2 virus, was reported in Wuhan of China in December 2019. The world is still in a state of pandemic owing to COVID-19. COVID-19 vaccines help our bodies develop immunity against the virus that causes COVID-19 without having to get the illness. Herein, we describe a rare case of a critical disorder, hemophagocytic lymphohistiocytosis (HLH), in a patient with nephritic sclerosis associated with hypertension, following mRNA COVID-19 vaccination. HLH is a life-threatening hyperinflammatory syndrome caused by aberrantly activated macrophages and cytotoxic T cells that may rapidly progress to terminal multiple organ failure. PATIENT CONCERNS: An 85-year-old Japanese woman with chronic renal failure and hypertension was included in this study. Routine laboratory investigations provided the following results: white blood cell (WBC) count, 4.6 × 109/L; hemoglobin (Hb), 8.1 g/dL; platelet count, 27 × 109/L; blood urea nitrogen 48.9 mg/dL, and serum creatinine 3.95 mg/dL. The patient developed malaise, vomiting, and persistent high fever (up to 39.7°C) on the 12th day after receiving the second dose of the vaccine. Initial evaluation revealed neutropenia. The total WBC count was 0.40 × 109/L (Neutrophils 0, Lymphocytes 240/µ, blast 0%); Hb 9.0 g/dL, platelet count 27 × 109/L; and, C Reactive Protein 9.64 mg/dL. DIAGNOSIS: Further tests showed hyperferritinemia (serum ferritin 2284.4 µg/L). Bone marrow examination revealed haemophagocytosis. A provisional diagnosis of HLH associated with the Comirnaty® vaccination was made based on the HLH-2004 diagnostic criteria. INTERVENTIONS: The patient was treated with granulocyte colony-stimulating factor and 500 mg methylprednisolone. OUTCOMES: A significant improvement was observed in the patient's condition; the abnormal laboratory results resolved gradually, and the patient was discharged. LESSONS: This case serves to create awareness among clinicians that HLH is a rare complication of COVID-19 vaccination and should be considered, especially in patients with a history of chronic renal failure and hypertension.

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.