Tape strips capture atopic dermatitis biomarkers in children

Minimally invasive tape strips captured immune-related and barrier-related markers of atopic dermatitis in lesional and non-lesional skin across pediatric age groups, according to a letter published in Allergy.

In fact, tape strips could be a painless technique for monitoring and predicting responses, Emma Guttman-Yassky, MD, PhD, Waldman Professor and System Chair of the Kimberly and Eric J. Waldman Department of Dermatology at the Icahn School of Medicine at Mount Sinai, and colleagues wrote in the letter.

“It’s important in children to identify biomarkers in a minimally invasive way, because we cannot take biopsies,” Guttman-Yassky, who also is a member of Healio’s Allergy/Asthma Peer Perspective Board, told Healio.

According to the researchers, biopsies are not suitable for recurrent assessments of AD among children. Also, blood abnormalities related to AD are delayed and difficult to detect compared with skin abnormalities, the researchers continued.

Emma Guttman-Yassky

“Having the ability to identify the phenotype of children in a noninvasive way was what prompted our study,” Guttman-Yassky said.

The study involved 44 patients with moderate to severe AD in consecutive age groups and 52 age-appropriate controls. The researchers serially collected tape strips from lesional and non-lesional skin with and without AD.

Next, the researchers conducted reverse transcription polymerase chain reaction testing of 74 markers related to AD from tape-stripped skin, followed by linear regression to compare different age groups.

“You apply a tape to the skin. Each time it is removed, some particles of skin come off, just like a Band-Aid, and they are subjected to monoclonal studies in the lab,” Guttman-Yassky said. “And it doesn’t leave a scar [like a biopsy would].” 

Tape strips from lesional and non-lesional skin presented upregulated markers of general inflammation and innate immunity such as MMP12, interleukin-8 and IL-6 for most age groups (fold change [FCH] > 2; P < .05).

The researchers also said that inducible T-cell costimulatory, or ICOS, which they called a marker for T-cell activation, was highly upregulated across all ages and AD samples (FCH > 12.5; P < .05).

Additionally, tape strips captured Th2-centered inflammation including markers related to AD such as CCL17/TARC and IL-13 that is characteristic of AD across all age groups.

Although it is not consistently upregulated in AD skin biopsies despite its key role in disease pathogenesis, the researchers found significant upregulation of the Th2 marker IL-4 in infant lesional and non-lesional skin and in adolescent skin (P < .05).

Tape strips further revealed upregulated S100A7/8/9, which is related to Th22 and Th17, in lesions across most of the age groups. Also, S100A12 was significantly upregulated in lesional and non-lesional tape strips across all ages.

Markers related to Th12 were increased overall across all age groups, with CCL20 and IL-23A appearing primarily in lesions, IL-19 exclusively upregulated in infants, and the negative regulator IL-34 upregulated in all age groups as well.

Calling them key markers in AD, the researchers also assessed barrier-related markers and found that although infants experience recent AD onset, they displayed the greatest abnormalities across all evaluated barrier-related markers.

Filaggrin/FLG and loricrin/LOR, which the researchers called pivotal terminal differentiation markers implicated in the pathogenesis of AD, showed greater and more significant downregulations than previously reported in full-depth AD biopsies for the same age groups.

Compared with biopsied skin, the researchers continued, tape strips captured significant downregulation of these markers in non-lesional skin, primarily in infants, although this could be explained by the thinner epidermis that infants have.

“Infants, children and adolescents all share type 2 inflammation,” Guttman-Yassky said. “But they also have some differences, and we may need to have specific targeting to different age groups.”

The researchers suggested that studies could further investigate the use of tape strips among patients with mild to severe AD and in response to different therapeutics across pediatric races and ages.

“It’s not common right now. It’s done only for research. But in the future, I can see how this will be something that we can evaluate in children in clinical trials, in clinical practice, and so on. It has applicability for use beyond research,” Guttman-Yassky said.

The next step, she continued, will be to evaluate the use of this tape in clinical trials in children to see if it is possible to identify these biomarkers and to explore how different treatments may change the phenotype in children.

“It’s exciting, since up until now, we didn’t have any means to evaluate the skin of children,” she said. “Now we have a means to identify biomarkers in children, and maybe this will lead to new treatment.”

For more information:

Emma Guttman-Yassky, MD, PhD, can be reached at emma.gutman@mountsinai.org.