The first of these new patented assays, Smoke Signature,™ exactly measures the level of methylation to determine the number of cigarettes consumed by the patient. The dynamic range of the test is extremely high and can quantify the amount of smoking in both nascent and heavy users. The results of the test are relatively stable. It doesn’t really matter if use hasn’t occurred in the past several days. The signature will be there cannot not masked by any drug. With heavy use, a portion of the signature can last for years. Finally, because of the test relies on DNA, adulteration or contamination of any sample can be easily detected.
Figure 1. Our assay focuses on the bisulfite converted DNA from the promoters of key genes. Bisulfite conversion, a process invented in the 1990’s, changes non-methylated cytosine bases to uracils. Because DNA polymerases treat uracil like thymine, we can use probes that contain adenosine (A) or cytosine (C) to determine the percent methylation at a given methylation site.
The test is specific for smoking. Non-combustible forms of tobacco consumption (such as chew) or “vaping” nicotine do not affect this signature. As such, through the use of this assay, clinicians can differentiate between smoking and the use of e-cigarettes.
A Breakthrough for Addiction. Similar to the way that the hemoglobin A1C test revolutionized the treatment of diabetes, this test can revolutionize the treatment of smoking and other addictions. Right now, smoking cessation treatment works only about 5% of time. This low success rate frustrates patients and wastes precious resources. A major barrier to improving this abysmal success rate is the “awkward silence” in the clinical conversation during which both the provider and patient skate around the challenges of facing this addiction. By quickly measuring the exact amount of cigarette consumption, clinicians can skip the “awkward silence” and focus on the reasons treatment may not be working such as side effects, social barriers, and high costs of medication that prevent the patient from “kicking the habit.” Because we can exactly measure the amount of success, this test may allow clinicians and insurance companies to reward patients for quitting smoking-which is a “win-win” for everyone.