Development of CEMAkit™, a Urine Antibody-Based Test to Distinguish Smokers, Smoke-Free Product Users, and Non-Smokers

      Ivanov, N. V.; Binder, J.; Laroche, M.; Francius, L.; Salmon, E.; Stankov, M.; Hoeng, J.; Peitsch, M. C.

      Conference date
      Jun 5, 2023
      Conference name
      33rd Anniversary World Congress on Biosensors

      Smoking is a major risk factor for the development of diseases. A new generation of smoke-free products for adult smokers has been designed to significantly reduce the formation of toxicants in the aerosol, potentially resulting in reduced exposure. To assess whether this reduced exposure translates into beneficial molecular changes, it is essential to identify reliable molecular biomarkers that are easily measurable in human subjects and can discriminate between smokers, smoke-free product users, and non-smokers. To address the question of product compliance, we developed the CEMAkit™, a rapid lateral flow immunochromatographic assay for qualitative detection of cotinine and 2-cyanoethylmercapturic acid (CEMA) in human urine. The presence of cotinine (a metabolite of nicotine) indicates if a subject has been exposed to any nicotine-containing products. CEMA is a metabolite of acrylonitrile that has been established as a biomarker of smoking exposure. During the assay, the urine sample reacts with colloidal gold nanoparticles conjugated to either polyclonal antibodies directed against cotinine or monoclonal antibodies directed against CEMA. Both test lines appear when CEMA and cotinine are absent in the sample; the presence of CEMA and/or cotinine inhibit the signals, and the test lines do not appear. A colored line should always be present on the Control line marked “C,” indicating that a sufficient volume of urine was applied, and the sample migration occurred properly. In this work, we describe how we developed the CEMAkit™ test and demonstrate that it reaches 95% sensitivity to detect smokers, 88% sensitivity to detect smoke-free product users, and 100% specificity for non-smokers. Further evaluations in clinical studies will determine the impact of potential confounders on test performance.