New insights into why the sun makes lupus patients sick

Researchers from the University of Michigan Health have uncovered new details on why UV exposure can trigger lupus symptoms in patients. The skin of individuals with systemic lupus erythematosus, commonly referred to as lupus, produces higher levels of inflammatory substances after exposure to UVB wavelengths, which compels patients to avoid sunlight.

However, the underlying cellular mechanisms behind this heightened sensitivity remain unclear. Published in Science Translational Medicine, a study led by the Kahlenberg Lab at U-M Health utilized single-cell RNA sequencing to investigate the immune response of lupus patients to UVB exposure. The findings revealed a common cellular response, specifically monocyte-derived dendritic cell infiltration, in both healthy control (HC) and lupus-affected skin.

Michelle Kahlenberg, the lead researcher, elucidated that this heightened reaction is characterized by excessive interferon production, resulting in vascular activation and the recruitment of inflammatory cells, which may ultimately lead to lupus rashes and subsequent systemic flare-ups. By identifying these critical pathways, the Kahlenberg Lab aims to develop targeted therapies to mitigate photosensitivity and prevent lupus flare-ups.

Further research is underway to refine this knowledge and enhance the care and treatment of lupus patients.