Tralokinumab treatment produces beneficial changes in skin microbiota, such as increasing microbial diversity, decreasing Staphylococcus aureus (S.aureus) abundance, and increasing the abundance of commensal coagulase-negative Staphylococci.
Atopic dermatitis (AD) is a chronic skin condition that can cause discomfort, itching, and a reduced quality of life. Research suggests that individuals with atopic dermatitis have less diverse microbial communities on their skin and are more likely to have high levels of harmful bacteria like Staphylococcus aureus. Recent studies have explored the impact of biologics on this imbalance in AD skin. Tralokinumab, a monoclonal antibody that neutralizes IL-13, has shown promising results in treating moderate-to-severe AD. A recent study published in the Journal of the American Academy of Dermatology investigated the impact of tralokinumab on microbial diversity in adults with moderate-to-severe AD, and found that it could be a promising treatment option for conditions involving imbalanced skin microbiota.
Reduction of S. aureus After Tralokinumab Treatment
Tralokinumab treatment led to a 20.7-fold reduction in S. aureus abundance on the skin over 16 weeks. In contrast, those who received a placebo only showed a 2.1-fold nonstatistically significant reduction in S. aureus gene copy number.
Impact of Tralokinumab Treatment on Microbial Diversity
Tralokinumab treatment also led to an increase in skin microbial diversity. The relative abundance of major phyla and genera remained stable for those who received the placebo treatment. However, for those who received tralokinumab treatment, the relative abundance of the genus Staphylococcus was significantly reduced, and the overall proportion of other bacterial genera increased. This increase in microbial diversity was assessed using the Shannon diversity index.
Tralokinumab Treatment Works Independently of Skin Improvement
The reduction in S. aureus abundance was not simply due to improved skin condition. The reduction in S. aureus abundance was observed regardless of whether there was a significant improvement in skin condition, as assessed by the Eczema Area and Severity Index (EASI-75) response.
The study also found correlations between S. aureus abundance and other factors. For example, at baseline, S. aureus abundance was moderately correlated with IL-13, IL-22, and CCL17/TARC levels, as well as with IgE and the absolute eosinophil count.
These findings suggest that tralokinumab treatment may have broader implications for the treatment of skin conditions beyond its effect on S. aureus abundance.
Beck, L. A., Bieber, T., Weidinger, S., Tauber, M., Saeki, H., Irvine, A. D., Eichenfield, L. F., Werfel, T., Arlert, P., Jiang, L., Røpke, M., & Paller, A. S. (2023). Tralokinumab treatment improves the skin microbiota by increasing the microbial diversity in adults with moderate-to-severe atopic dermatitis: Analysis of microbial diversity in ECZTRA 1, a randomized controlled trial. J Am Acad Dermatol, 88(4), 816-823. https://doi.org/10.1016/j.jaad.2022.11.047