Trends in Mortality Rates From Hemophagocytic Lymphohistiocytosis in the United States From 2010 to 2023

TL;DR

Mortality rates from a rare and deadly immune disorder called hemophagocytic lymphohistiocytosis have risen sharply in the U.S. from 2010 to 2023.

Contribution

This study is the first to document a consistent and significant 12-fold increase in age-adjusted mortality rates for HLH in the U.S. over a 13-year period.

Findings

Age-adjusted mortality rates from HLH increased 12-fold from 2010 to 2023.

The mortality trend was consistent across all U.S. census regions and most demographic groups.

Yearly increases in mortality were statistically significant for most years in the study period.

Abstract

Hemophagocytic lymphohistiocytosis (HLH) is a severe, life-threatening condition marked by uncontrolled T-lymphocyte and macrophage-mediated inflammation, usually secondary to an underlying malignancy or infection in adults. It leads to multiorgan failure and death if not promptly recognized and treated; adult secondary HLH carries an overall mortality rate of 57% in an ICU population regardless of treatment. We examined trends in age-adjusted mortality rates from the Centers for Disease Control and Prevention's Wide-ranging Online Data for Epidemiologic Research (CDC WONDER) database to further characterize this interesting multinational finding in an otherwise rare disease. Age-adjusted mortality rates (AAMRs) from HLH showed consistent yearly increases, most of which were statistically significant, with an overall 12-fold rise from 2010 to 2023. This trend was mirrored in all census regions and in most demographic categories.

Figures