Different effects of prenatal air pollution exposure on cord blood protein profiles and postnatal lung function in infants born to asthmatic mothers.

RATIONALE: Prenatal exposure to air pollution is linked to impaired infant lung function. At-risk infants, such as those born to mothers with asthma during pregnancy, may be more vulnerable.

OBJECTIVES

Investigate whether prenatal particulate matter ⩽2.5 μm in aerodynamic diameter (PM2.5) exposure is associated with lung function and cord blood proteins in infants of mothers with asthma during pregnancy compared to those of non-asthmatics.

METHODS

In the Swiss Basel-Bern Lung Development and the Australian Breathing for Life Trial cohorts, we investigated associations between prenatal PM2.5 exposure, lung function, and cord blood proteins (n = 433 infants of asthmatic mothers; n = 620 of non-asthmatic mothers).

RESULTS

PM2.5 exposure was inversely associated with functional residual capacity, with stronger reductions among infants of asthmatic mothers (β -0.19 SD, p < 0.001) than those of non-asthmatics (β -0.08 SD, p = 0.059; p for interaction = 0.031). Exposure was associated with increased FeNO in infants of asthmatic mothers (β = 0.12 SD, p = 0.050), but decreased FeNO (β -0.15 SD, p = 0.003) for those of non-asthmatics (p for interaction = 0.001). The association between maternal PM2.5 exposure and cord blood protein levels differed by maternal asthma status. Infants of asthmatic mothers had higher VEGF-A (1.02 SD, p = 0.016), IL-9 (0.44 SD, p = 0.042), IL-10 (0.41 SD, p = 0.048), and IL-13 (0.43 SD, p = 0.046) concentrations than those of non-asthmatics who only had higher TNF-α (0.08 SD, p = 0.041). However, after multiple-comparison correction, these associations did not remain significant.

CONCLUSION

Lung function in infants of mothers with asthma during pregnancy is more affected by PM2.5 compared to those of non-asthmatic mothers. Different PM2.5 association patterns for FeNO and cord blood proteins may indicate different host response mechanisms.