Now accepting Telehealth appointments. Schedule a virtual visit.

Personalized Medicine: Can We Really Achieve This in Dermatology? 3. Our Microbiome, Genomic Testing

Our Microbiome

We must devote much more time to analyze the microbiome in comprehensive detail in order to help create a healthy human and society. As Paul Nurse writes, “When scientists look at our own bodies, they see that for each and every one of our 30 trillion or more human cells, we have at least one microbial cell. You – and every other human being – are not an isolated, individual entity, but a huge and constantly changing colony made up of human and non-human cells. These cells of microscopic bacteria and fungi live on us and in us, affecting how we digest food and fight illnesses.”

Each of us has about as many bacteria and yeasts on the surface of his or her skin as there are people on earth. The life that lives upon us not only puts our lives in perspective but also allows us a peek at a world within the worlds of our integument, a view that is both strange and amazing to fathom. We humans are simply one of over two million species of animals and plants. And like our fellow mortal inhabitants, we are at the mercy of tiny viruses, bacterium, and yeasts. At no time in recent history has this become more clear than with the devastation caused by COVID-19.

Genomic Skin Testing

For the last year we have been participating in the Dermtech clinical testing and research project at our office for a variety of skin diseases by using “smart stickers.” In the case of melanoma, we know that early detection saves lives, and the Dermtech device facilitates in this goal. The status quo has been, for many, to biopsy any mole that looks remotely suspicious; this process often results in excess biopsies. The result had been a very limited accuracy, with 96% of biopsies taken testing negative for melanoma and 17% of the time missing early stage melanoma. Dermtech added a step before the scalpel and today the DermTech Melanoma Test is extremely accurate, with a 99% negative predictive value (a 99% probability that a negative test means you really don’t have the disease). All of this is happening at the genomic level with molecules more than 10,000 times smaller than cells.

Although it looks like a simple sticker tape, the proprietary adhesive is strong enough to pull 1.5 milligrams of tissue from the epidermis of a lesion to assess its genomic information but is without enough pull to cause pain or damage. For our research we do several adhesive tests per lesion and a non-lesional test for comparison and then follow with a biopsy of the lesion to test in our pathology lab. The adhesive collects and stores the genomic material so it can be sent via Fedex to DermTech’s Gene Lab for examination. Unlike a biopsy, which evaluates only 1-2% of the mole, DermTech’s smart sticker captures cells from 100% of the mole’s surface. We send Dermtech the results of our biopsies but we are unaware of the sticker results for comparison.

When the sticker samples arrive at Dermtech, they undergo an automated process that amplifies RNA molecules. In the case of melanoma detection, the following analysis determines if one or both genes that are highly predictive of melanoma, PRAME and LINC00518, are detectable in the sample through a proprietary gene expression test. The expression test to search for PRAME and LINC00518 is done through an amplification process called RT-PCR (a polymerase chain reaction) that makes billions of copies of these genes so the Dermtech scientists can study them in detail. When this analysis shows excessive levels of the PRAME and/or LINC00518 gene, it correlates with the presence of melanoma.

The DermTech Melanoma Test™ is a physician-ordered laboratory developed test (LDT) and is regulated under the Clinical Laboratory Improvement Amendments (CLIA). LuminateSM is in development by Dermtech to identify UV damage at the genomic level. To find the presence of non-melanoma skin cancers at the genomic level, the Carcinome test is currently in development.

If the Dermtech and other genomic tests prove effective, we may have a marked decrease in the number of biopsies and surgeries needed. The computer algorithms for testing and diagnosis biopsy specimens are rapidly improving and helping to eliminate the need for expensive and time-consuming special staining, immunohistochemistry and further examinations. When utilizing all the factors in a person’s health investigation and history, as mentioned earlier, AI suggestions will alert us to disease and prevention patterns and provide improvements in personalized dermatology.

Dr. Robert A. Norman

You Might Also Enjoy...