Is long-term particulate matter and nitrogen dioxide air pollution associated with incident monoclonal gammopathy of undetermined significance (MGUS)? An analysis of the Heinz Nixdorf Recall study.

BACKGROUND

Exposure to air pollution activates the innate immune system and influences the adaptive immune system in experimental settings. We investigated the association of residential long-term exposure to particulate matter (PM) and NO2 air pollution with monoclonal gammopathy of undetermined significance (MGUS) as a marker of adaptive immune system activation.

METHODS

We used data from the baseline (2000-2003), 5-year (2006-2008) and 10-year (2011-2015) follow-up examinations of the German Heinz Nixdorf Recall cohort study of 4814 participants (45-75years). Residential exposure to PM size fractions and NO2 was estimated by land-use regression (ESCAPE-LUR, annual mean 2008/2009) and dispersion chemistry transport models (EURAD-CTM, 3-year mean at baseline). We used logistic regression to estimate the effects of air pollutants on incident MGUS, adjusting for age, sex, education, smoking status, physical activity, and BMI. As a non-linear approach, we looked at quartiles (2-4) of the air pollutants in comparison to quartile 1.

RESULTS

Of the 3949 participants with complete data, 100 developed MGUS during the 10-year follow-up. In the main model, only PMcoarse was associated with incident MGUS (OR per IQR (1.9μg/m3): 1.32, 95% CI 1.04-1.67). We further found positive associations between PM size fractions estimated by ESCAPE-LUR and incident MGUS by quartiles of exposure (OR Q4 vs Q1: PM2.5 2.03 (1.08-3.80); PM10 1.97 (1.05-3.67); PMcoarse 1.98 (1.09-3.60)).

CONCLUSIONS

Our results indicate that an association between long-term exposure to PM and MGUS may exist. Further epidemiologic studies are needed to corroborate this possible link.