Identification of Systemic Markers from A Pulmonary Carbon Nanotube Exposure

OBJECTIVE: Interest exists for early monitoring of worker exposure to engineered nanomaterials. Here, we highlight quantitative systemic markers of early effects after carbon nanotube (CNT) exposure. METHODS: Mice were exposed by pharyngeal aspiration to 40-μg CNT and harvested 24 hours, 7 days, and 28 days postexposure for measurements of whole blood, lung and extrapulmonary tissue gene expression, blood and bronchoalveolar lavage (BAL) differentials, and serum protein profiling. RESULTS: Early effects included increased inflammatory blood gene expression and serum cytokines followed by an acute phase response (eg, CRP, SAA-1, SAP). Beyond 24 hours, there was a consistent increase in blood and BAL eosinophils. At 28 day, serum acute phase proteins with immune function including complement C3, apolipoproteins A-I and A-II, and α₂-macroglobulin were increased. CONCLUSIONS: Carbon nanotube exposure resulted in measurable systemic markers but lacked specificity to distinguish from other pulmonary exposures.