Identifying atopic dermatitis molecular phenotype in African patients benefits treatment

Key takeaways:

• Molecular skin profiling can be beneficial in atopic dermatitis treatment development.
• East African and African American patients with AD had similar T helper 2 skewing.

NEW ORLEANS — In patients with atopic dermatitis, skin phenotypes were similar between East African and African American individuals in comparison with those of European American ethnicity, according to a presenter here.

East African and African American patients with AD were both found to have skin phenotypes with T helper 2 (Th2) skewing that showed less noticeable dysregulation but broader attenuation of lipid metabolism products. These findings, presented at the American Academy of Dermatology Annual Meeting, could help inform treatment practices in patients of African descent.

“While the molecular phenotype of atopic dermatitis has been well characterized in the literature, most of the research focuses on patients of European ancestry, and there is a dearth of studies examining AD patients of African descent and especially in patients in Africa,” Ester Del Duca, MD, post-doctoral fellow in the Laboratory of Inflammatory Skin Diseases at Mount Sinai, told Healio.

Del Duca presented results from the first study characterizing gene expression in patients identifying as African American, East African and European American, both in healthy and AD skin.

Lesional and nonlesional skin samples from 60 patients with AD — 10 from East Africa and Tanzania, 25 African Americans and 25 European Americans — were collected, along with samples from 60 controls matched for age and ethnicity.

All groups had upregulation of key AD immune genes including T-cell activation and recruitment markers Th2 and Th22. East African patients did not show up-regulation of innate immune genes interleukin (IL)-6 and IL-17, as well as Th1 axis, while both European American and African American patients did.

Significant downregulation of barrier lipids products were observed in all groups; however, there was a more prominent downregulation in East African and African American patients vs. European American patients. Only the European American group had a more robust downregulation of the FLG, LOR and PSORS1C2 genes.

“We confirmed Th2 activation in East African AD patients, consistent with African American and European American populations, with important implications for targeted therapeutics,” Del Duca told Healio. “We also demonstrated distinct molecular differences in barrier abnormalities between East African, African American and European Americans that can inform clinical presentation and potential treatment options.”

While the findings showed similarities between African American and East African patients, they also reflected genetic diversity represented in Africa and African migration, she added.