Abstract
Background and aims Environmental exposures may play a substantial role in the pathogenesis of SLE. It recently became possible to identify and quantify a person’s exposure to environmental chemicals (“the exposome”) in a comprehensive fashion. This non-targeted approach has no a priori selection of chemicals. The goal of this study is to characterise multiple organic chemicals in a cohort of SLE patients and controls.
Methods Patients from the California Lupus Epidemiology Study and healthy controls were studied. Banked serum was analysed by Liquid Chromatography Quadruple Time-of-Flight Mass Spectrometry (LC-QTOF/MS). Data acquired by LC-QTOF/MS includes the molecular weights of all detected parent and daughter ions, as well as retention times and peak areas. This non-targeted screening allows rapid identification of potential hits. The results of the LC-QTOF/MS analysis are matched into a database of 740 potentially detected environmental organic chemicals [EOC].
Results We present preliminary data on 19 patients with SLE and 43 controls. 193 potential EOC hits were found in patients with SLE and 417 were found in controls. In SLE patients, the number of chemicals detected per participant ranged from 34–66, with an average of 50 hit matches. Pthalates and its metabolites were the most represented chemicals, with >50% of detected compounds in SLE. (Figure 1) Compounds of relevance include several endocrine disruptors such as Bisphenol A and Methoxyclor.
Environmental Organic Chemicals detected in SLE patients
Conclusions Patients with SLE are exposed to a wide range of chemicals. LC-QTOF/MS can identify a wider range of potential chemical exposures in SLE, and aid in prioritising chemicals for further research and interventions.
