Changes in Serum Proteins in Firefighters Responding to the 2025 Los Angeles Urban Conflagrations.

Abstract

The study goal was to evaluate changes in serum proteins following firefighter exposure to the January 2025 Los Angeles area urban conflagrations. The serum proteome was evaluated in 42 firefighters enrolled in the Fire Fighter Cancer Cohort Study with blood specimens collected in 2024 and in January and February of 2025, an average of 8.6 days after their most recent response to the urban conflagrations. Sixty proteins changed significantly from before to after exposure. These proteins were associated with nucleotide synthesis and repair, oxidative stress response, energy metabolism, and other mechanisms. Pathway analysis identified changes in metabolism and oxidative stress, immune and inflammatory responses, cellular barrier integrity and trafficking, and growth/cancer signaling. Response to the Los Angeles area urban conflagration was associated with a change in the serum proteome of firefighters.