Haemophagocytic lymphohistiocytosis secondary to COVID-19: a case series

Improved survival outcomes with anakinra over etoposide-based therapies for the management of adults with hemophagocytic lymphohistiocytosis: a retrospective multicenter research network study

Background

Hemophagocytic lymphohistiocytosis (HLH) is a rare life-threatening, hyperinflammatory syndrome for which etoposide-based regimens have historically been the standard of care. Recent reports have described positive outcomes with the utilization of ruxolitinib or anakinra although these studies are often limited to small samples.

Objectives

We aimed to compare the efficacy of ruxolitinib, anakinra, and etoposide-based therapies for the management of HLH in adult patients.

Design

We performed a population-based, multicenter, retrospective cohort study utilizing the TriNetX Networks database.

Methods

Adult patients (⩾18 years) diagnosed with HLH who received first-line treatment with ruxolitinib, anakinra, or etoposide between 2008 and 2023 were analyzed. The primary endpoint was overall survival (OS) at 1 year. A 1:1 propensity-score matching analysis was utilized.

Results

Anakinra (p = 0.020) but not ruxolitinib (p = 0.19) resulted in a significantly higher 1-year OS when compared with etoposide-based therapies.

Conclusions

Anakinra is effective for the management of adult patients with HLH.

Does your unwell patient have haemophagocytic lymphohistiocytosis?

Haemophagocytic lymphohistiocytosis is a severe systemic hyperinflammatory syndrome characterised by dysregulation of immune cells and excessive production of cytokines, also known as a cytokine storm. It has distinctive clinical features with fever, hyperferritinaemia and falling blood counts. In adults, this usually occurs secondary to an underlying driver or trigger including infection, malignancy or rheumatic diseases. Prompt treatment with immunomodulatory therapy, including corticosteroids and the recombinant IL-1 receptor antagonist anakinra, is recommended to switch off the cytokine storm. Etoposide-based regimens are sometimes needed, and newer therapies such as emapalumab and JAK inhibitors are increasingly being used. The incidence of haemophagocytic lymphohistiocytosis has increased significantly over the last 20 years which may partly reflect increased awareness of the condition. Although relatively rare, haemophagocytic lymphohistiocytosis can be encountered by a broad range of hospital physicians, so knowing how to diagnose and treat this condition is essential. This article reviews the pathogenesis, clinical features, causes, diagnosis and treatment of haemophagocytic lymphohistiocytosis to improve physician recognition and management of this condition to improve future patient outcomes.

Secondary Hemophagocytic Lymphohistiocytosis: Think of the Devil Lurking!

How to cite this article: Pannu AK, Bhalla A. Secondary Hemophagocytic Lymphohistiocytosis: Think of the Devil Lurking! Indian J Crit Care Med 2022;26(5):545-546.

Haemophagocytic lymphohistiocytosis following COVID-19 mRNA vaccination

The development of vaccinations has been instrumental in the ongoing effort to combat the COVID-19 pandemic. Although the benefits of vaccination are unquestionable, there have been reports of potentially rare life-threatening complications following vaccination including thrombocytopaenia, haemolytic anaemia, vasculitis and myocarditis. Haemophagocytic lymphohistiocytosis (HLH), a rare but life-threatening inflammatory condition, has also been described postadenoviral vector COVID-19 vaccination but it has never been reported post-messenger RNA (mRNA) COVID-19 vaccination. We report two cases of HLH admitted to our hospital after administration of COVID-19 mRNA vaccines. We also searched the vaccine adverse event reporting system and found 50 reports of suspected HLH following COVID-19 vaccination. Presently, we cannot define a causality between COVID-19 mRNA vaccination and HLH development. However, we hope the reporting of our two cases (and additional cases seen in the adverse event reporting database) will help us determine whether there is a potential relationship. Prompt recognition of this condition is of utmost importance to initiate life-saving therapy.