Diagnosis, Treatment, and Management of Hemophagocytic Lymphohistiocytosis in the Critical Care Unit. In: Duncan CN, Talano JM, Mcarthur JA, editors. Critical Care of the Pediatric Immunocompromised Hematology/Oncology Patient. Cham: Springer International Publishing; 2019. pp. 159-82. [DOI: 10.1007/978-3-030-01322-6_9]

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.

Navigating the Complexity: A Comprehensive Review of Hemophagocytic Lymphohistiocytosis Associated With Dengue Infection

Hemophagocytic lymphohistiocytosis (HLH) associated with dengue infection presents a unique challenge in clinical practice due to its rarity, rapid progression, and overlapping clinical features. This comprehensive review navigates the complexity of HLH-dengue syndrome by examining its pathophysiology, clinical manifestations, diagnostic criteria, and therapeutic strategies. HLH, characterized by uncontrolled immune activation and cytokine dysregulation, can occur as a secondary complication of dengue infection, leading to severe multiorgan dysfunction and high mortality if not promptly recognized and treated. The review underscores the significance of early diagnosis through vigilant clinical monitoring and appropriate diagnostic tests, such as bone marrow examinations and genetic studies. Collaboration between infectious disease specialists, hematologists, and critical care teams is essential for optimal management. Despite advancements in understanding HLH-dengue syndrome, further research is needed to elucidate its underlying mechanisms and explore novel treatment approaches. This review provides insights into the clinical implications of HLH-dengue syndrome and emphasizes the importance of a multidisciplinary approach to improve patient outcomes in this challenging clinical scenario.

Severe Cytokine Release Syndrome and Hemophagocytic Lymphohistiocytosis (HLH)-Like Syndrome Following Administration of Combined Brentuximab Vedotin and Nivolumab for Recurrent Classical Hodgkin Lymphoma: A Case Report

Brentuximab vedotin (BV) and nivolumab are increasingly utilized as a novel regimen in patients with relapsed/refractory classical Hodgkin lymphoma (cHL). A 26-year-old male presented to the hospital with refractory diabetic ketoacidosis and multiple electrolyte abnormalities, 9 days after the first dose of brentuximab vedotin and nivolumab for recurrent classical Hodgkin lymphoma. During his hospitalization, he developed multi-organ failure. His workup showed elevated cytokine levels concerning severe cytokine release syndrome (CRS) and hemophagocytic lymphohistiocytosis (HLH)-like syndrome. Despite treatment with CRS- and HLH-directed therapies, his clinical status deteriorated due to ongoing multifactorial shock and worsening multi-organ dysfunction, and comfort care measures were eventually pursued. To our knowledge, there have been no other cases reported of HLH-like syndrome after the combination of BV and nivolumab in patients with cHL. This case of a fatal adverse event following one dose of BV and nivolumab underscores the vital need for close monitoring of patients receiving this treatment regimen.

A Case Report of Aggressive Post-Infectious Hemophagocytic Lymphohistiocytosis in an Immunocompetent Adult

Hemophagocytic lymphohistiocytosis (HLH) is an acute inflammatory syndrome triggered by immune events such as infections, inflammation, autoimmune diseases, and malignancies. Initial presentations can range from vague symptoms to infectious features such as fever. Given its aggressive nature, timely diagnosis and immediate treatment are crucial to achieving optimal patient outcomes. Recently, the HLH score (HScore) criteria have been applied as diagnostic criteria, offering a broader scope compared to the previous HLH-2004 score, which was primarily based on pediatric populations. The standard treatment for decades has involved the combination of etoposide and high-dose steroids, and it is recommended to initiate treatment as soon as possible, even in the absence of a bone marrow test or when there is suspicion of the diagnosis. In this case presentation, we aim to underscore the significance of maintaining a high level of suspicion for HLH and the importance of promptly initiating treatment.

Hemophagocytic Lymphohistiocytosis Associated With Polyserositis and Salmonella typhi Infection

Hemophagocytic lymphohistiocytosis (HLH) is a rare but potentially fatal disease characterized by excessive immune response activation. Numerous conditions, including infectious etiologies, are implicated in its development. We report the case of a 16-year-old girl with HLH associated with polyserositis and Salmonella typhi infection. A 16-year-old girl presented with a high-grade fever and abdominal pain that had been ongoing for 20 days. She had been treated for malaria at a local hospital but was referred to our hospital due to the worsening of her condition. On examination, she was found to have an enlarged liver and spleen, pale skin, and hypotension, with bilateral basal crackles on chest examination. Her blood profile revealed pancytopenia, elevated C-reactive protein, and a deranged coagulation profile. Peripheral smears showed anisocytosis, microcytes, hypochromia in RBCs, and a few platelet clumps. A bone marrow biopsy revealed increased megakaryocytes and hemophagocytes. Ultrasound and computed tomography of the abdomen and pelvis showed hepatosplenomegaly, pericholecystic edema, mild ascites, and long-segment diffuse colonic wall thickening, suggesting pancolitis. Blood culture revealed S. typhi, which is rarely associated with HLH. The patient was started on the HLH-2004 protocol and showed improvement on the fourth day of initiating therapy, but due to a delayed diagnosis, the patient collapsed on the sixth day of admission. HLH is a rare but life-threatening disease with various underlying causes. The diagnosis of HLH is challenging, and early diagnosis and prompt treatment are crucial for a better prognosis. The association between HLH and S. typhi infection is rare, and this case highlights the importance of considering unusual etiologies in HLH. Clinicians should be vigilant about this association, especially in endemic regions, to ensure early diagnosis and prompt treatment.

Hemophagocytic Syndrome and COVID-19: A Comprehensive Review

Hemophagocytic lymphohistiocytosis (HLH), a hyperinflammatory hyperferritinemic syndrome, is triggered by various etiologies and diseases and can lead to multiorgan dysfunction and death. There are two types of HLH: primary and secondary. Primary HLH (pHLH) is caused by a genetic mutation resulting in dysfunction in cytotoxic T lymphocytes (CTLs), natural killer (NK) cells, hyperactivated immune cells, and hypercytokinemia. In secondary HLH (sHLH), an underlying etiology is the cause of the disease. Infections, malignancy, and autoimmune diseases are well-known triggers for sHLH. Infectious triggers for sHLH are most frequently viruses, where different mechanisms, including dysregulated CTLs and NK cell activity and persistent immune system stimulation, have been reported. Similarly, in severe coronavirus disease 2019 (COVID-19) patients, a hyperinflammatory mechanism leading to hypercytokinemia and hyperferritinemia has been demonstrated. A similar dysfunction in CTLs and NK cells, persistent immune system stimulation with increased cytokines production, and severe end-organ damage have been reported. Therefore, a significant overlap is present between the clinical and laboratory features seen in COVID-19 and sHLH. However, SARS-CoV-2, similar to other viruses, can trigger sHLH. Hence, a diagnostic approach is needed in severe COVID-19 patients presenting with multiorgan failure, in whom sHLH should be considered.

Pediatric inborn errors of immunity causing hemophagocytic lymphohistiocytosis: Case report and review of the literature

Inborn errors of immunity are a group of genetic disorders caused by mutations that affect the development and/or function of several compartments of the immune system, predisposing patients to infections, autoimmunity, allergy and malignancies. In this regard, mutations that affect proteins involved in trafficking, priming, docking, or membrane fusion will impair the exocytosis of lytic granules of effector NK and cytotoxic T lymphocytes. This may predispose patients to hemophagocytic lymphohistiocytosis, a life-threatening immune disorder characterized by systemic lymphocyte and macrophage activation, and increased levels of cytokines, which lead to an uncontrolled hyperinflammation state and progressive multiorgan damage. In this review, we will describe a clinical case and recent advances in inborn errors of immunity predisposing to hemophagocytic lymphohistiocytosis. Summary sentence: Review of recent advances in inborn errors of immunity predisposing to hemophagocytic lymphohistiocytosis.

Hemophagocytic Lymphohistiocytosis After Trauma Due to a Motor Vehicle Accident: A Case Report

Hemophagocytic lymphohistiocytosis (HLH) is an underdiagnosed, rare clinical syndrome, in particular secondary HLH, which mostly affects adults. HLH can be caused by malignancy, infections, autoimmune disorders, and, rarely, trauma. Here, we present the case of a patient who presented with anemia not responding to blood transfusion but improved after treatment with intravenous immunoglobulin. This case aims to highlight a rare presentation of this disease (HLH secondary to trauma) and to discuss the current HLH diagnostic criteria.

Hemophagocytic lymphohistiocytosis occurring after liver transplantation: A case series and review of the literature

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening disease characterized by excessive inflammation and tissue destruction due to a dysregulated immune response. Its secondary form is most commonly triggered by viral infection or malignancy. There have previously been 11 cases of acquired HLH described following liver transplantation in adult transplant recipients, most occurring within the first year following transplantation. Herein, we describe two cases of HLH in liver transplant recipients that both occurred remotely following transplantation. In the first case, HLH was thought to be triggered by the development of a post-transplant lymphoproliferative disorder in a patient who was initially diagnosed with recurrent autoimmune hepatitis. In the second, it was thought to be triggered by a newly acquired human herpesvirus-8 infection. In both cases, the syndrome was not recognized until treatment for the initial putative diagnoses was unsuccessful. Despite treatment, both patients unfortunately died from multiorgan failure. HLH in the post-liver transplant setting is likely under-recognized and has a high mortality; early diagnosis and intervention may lead to improved outcomes.

Novel mutation in perforin gene causing familial hemophagocytic lymphohistiocytosis type 2 in an Egyptian infant: case report

Background

Hemophagocytic lymphohistiocytosis (HLH) is a syndrome of pathological immune activation characterized by clinical signs and symptoms of extreme inflammation. It results from the uninhibited proliferation and activation of cells of the macrophage lineage and leads to the production of excess amounts of pro-inflammatory cytokines. The familial form of HLH disease is due to mutations in several genes necessary for natural killer (NK) cell and T cell granule-mediated cytotoxic function. These genes are involved in sorting, trafficking, docking, and fusion of cytotoxic granules containing granzymes A and B and perforin to the cell membrane of the target cell (using the proteins LYST, AP-3 complex, Rab27a, Munc 13–4, Munc 18–2, syntaxin 11). Defect in any of those proteins results in defective cytotoxicity. Consequently, genes included in these steps play valuable roles in the pathogenesis of familial HLH disease including perforin (PRF1) gene in which defect causes familial HLH type 2 (FHL2).

Case presentation

A 2-year-old boy suffered from hepatosplenomegaly and fever. He fulfilled the required criteria for the diagnosis of HLH according to HLH-2004 diagnostic criteria. We screened the patient for the presence of mutations in the coding exons and of PRF1 gene by PCR amplification of genomic DNA followed by direct sequencing of the PCR products. We report a novel homozygous deletion/insertion frameshift mutation in PRF1 gene (M28393: exon 2: c.536delAinsCG p.F178fs). We treated him with HLH 2004 protocol of treatment and showed a remarkable response with resolution of fever and decrement in the size of hepatosplenomegaly.

Conclusions

Our study discovered a novel frameshift mutation in PRF1 gene in an infant with HLH disease, and it is the first report of this type of mutation in Egyptian patients with this disease.