Is peripheral blood sampling adequate?
In addition to saying that the algorithm will need to prove that it alters outcomes, Samuel Tzen-yue Hwang, MD, PhD, professor and chair of the department of dermatology at the University of California, Davis, Sacramento, pointed out some potential practical issues.
“Flow cytometry is not typically available as a rapid throughput, and the cost is high,” he said. Moreover, he remains skeptical about performing this algorithm on the basis of peripheral blood samples.
Dr. Samuel T. Hwang
“It is debatable that looking at peripheral cells would provide adequate information about what is taking place at sites of inflammation,” he said. Although it would “be fantastic” to develop an algorithm that required only a peripheral blood sample, he pointed out that “only a fraction of these cells is relevant” to disease activity.
Aspirating fluid from an involved joint “might be more useful,” but it is more work, he added. Yet, Dr. Hwang acknowledged that this approach is intriguing. He agreed that there is considerable heterogeneity among patients with PsA in their response to specific biologics, and a method to better direct patients to the treatment most likely to elicit a response is needed.
Dr. Ayan and Dr. Hwang reported no potential conflicts of interest.