“Research shows about 19 per cent of African Americans and 16 per cent of European Americans are diagnosed with AD,” said senior author Emma Guttman-Yassky, in a press release. “Our study found there are significant differences in the skin of people with AD than in those without the condition. Furthermore, we found African Americans with AD have more inflammation than European Americans with the condition.”
Dr. Guttman-Yassky is a professor of dermatology, medicine, and clinical immunology, and vice chair of the department of dermatology at the Icahn School of Medicine at Mount Sinai Medical, New York.
Investigators conducted genetic and immunohistochemistry studies in lesional and non-lesional skin of psoriasis patients of both African and European backgrounds, and in healthy controls.
They found that the AD lesions in patients of African descent showed a greater infiltration of dendritic cells compared to the lesions of patients with a European background. As well, the lesions in patients with an African background featured decreased expression of innate immune markers, and T-helper (Th)1- and Th17-cell-related markers.
AD clinical severity significantly correlated with Th2 and Th22-related products, as well as serum IgE, in the patients of African background.
Fillagrin was only downregulated in AD patients with a European background. While loricrin was downregulated in both AD cohorts, it negatively correlated with clinical severity in the African-background patients.
According to the release, molecular profiling of skin is being used to develop newer, more effective treatments for people with AD, yet to date only AD patients with a European background have been included in the research to develop this profiling technique.
“This study looked for differences in the molecular profile of the skin of African Americans with AD compared to the skin of European Americans with AD to determine if there are differences that might improve treatment options for African Americans,” said Dr. Guttman-Yassky. “The results indicated that the immune profile was more unbalanced in African Americans with AD compared to European Americans.”
The authors suggest that the findings from this study could explain variances in the severity of AD in patients of African descent and differences in response to similar treatments.
“This may prove to be a valuable enhancement for treatment options for African Americans with AD,” says allergist Donald Leung, MD, PhD, executive editor of Annals of Allergy, Asthma and Immunology, in the release. Dr. Leung was not an author on the paper. “It will also reinforce the importance of racial diversity in clinical research studies for effective treatment for AD.”