Ambient PM2.5 Exposure Up-regulates the Expression of Costimulatory Receptors on Circulating Monocytes in Diabetic Individuals.

COMPUTER software; CONFIDENCE intervals; PEOPLE with diabetes; GENE expression; IMMUNITY; INSULIN resistance; MONOCYTES; OZONE; RESEARCH funding; DATA analysis; ENVIRONMENTAL exposure; PARTICULATE matter; REPEATED measures design

Background: Exposure of humans to air pollutants such as ozone and particulate matter (PM) may result in airway and systemic inflammation and altered immune function. One putative mecha­nism may be through modification of cell-surface costimulatory molecules. oBjectives: We examined whether changes in expression of costimulatory molecules on circulating cells are associated with ambient levels of fine PM [aerodynamic diameter ? 2.5 ?m (PM2.5)] in a susceptible population of diabetic individuals. Methods: Twenty subjects were studied for 4 consecutive days. Daily measurements of PM2.5 and meteorologic data were acquired on the rooftop of the exam site. circulating cell-surface markers that mediate innate immune and inflammatory responses were assessed by flow cytometry on each day. Sensitivity analysis was conducted on glutathione S-transferase M1 (GSTM1) genotype, body mass index, and glycosylated hemoglobin A1c (HbA1c) levels to determine their role as effect modifiers. Data were analyzed using random effects models adjusting for season, weekday, and meteorology. results: We found significantly increased monocyte expression (mean fluorescent intensity) of CD80, CD40, CD86, HLA-DR, and CD23 per 10-?g/m3 increase in PM2.5 at 2- to 4-day lag times after exposure. These findings were significantly higher in obese individuals, in individuals with HbA1c > 7%, and in participants who were GSTM1 null. conclusions: Exposure to PM2.5 can enhance antigen-presenting cell phenotypes on circulating cells, which may have consequences in the development of allergic or autoimmune diseases. These effects are amplified in diabetic individuals with characteristics that are associated with insulin resis­tance or with oxidative stress. [ABSTRACT FROM AUTHOR]

Copyright of Environmental Health Perspectives is the property of National Institute of Environmental Health Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)