Associations Between Household Particulate Matter and Inflammatory Cytokines in Cystic Fibrosis.

Individuals with cystic fibrosis (CF) are vulnerable to environmental exposures due to impaired pulmonary defense mechanisms, yet the contribution of the indoor environment to inflammatory signaling in CF remains poorly understood. While prior studies have focused on ambient air pollution and clinical outcomes, less is known about how short-term indoor particulate matter exposure relates to systemic immune biomarkers. In this pilot study, we evaluated associations between household fine particulate matter (PM2.5) concentrations and circulating cytokines in adults with CF. Participants underwent four to eleven days of in-home PM2.5 monitoring using real-time air quality sensors. Circulating inflammatory cytokines were measured from blood samples collected using a multiplex immunoassay. PM2.5 exposure was characterized using two metrics: mean PM2.5 concentration across the monitoring period and the percentage of monitoring time with indoor PM2.5>35 μg/m3. Associations between PM2.5 exposure and cytokine concentrations were assessed using Spearman rank correlations. While mean PM2.5 concentration was not associated with cytokine levels, the percentage of monitoring time with indoor PM2.5>35 μg/m3 was associated with variation in circulating cytokines. PDGF-AA/BB suggested a moderate, statistically significant positive correlation with the percentage of monitoring time with PM2.5>35 μg/m3, while IL-7 and IL-8 showed positive but non-significant trends. TNF-α exhibited a non-significant negative association. These findings suggest that time spent at elevated indoor PM2.5 concentrations may be relevant to systemic inflammatory signaling in adults with CF and support further investigation into modifiable indoor environmental exposures.