Extracellular Vesicles Explored as Lupus Biomarkers
A new article published by Spanish researchers focuses on whether extracellular vesicles may be used to detect and monitor systemic lupus erythematosus. The work, titled “Extracellular Vesicles as Biomarkers of Systemic Lupus Erythematosus,“ appeared August 25th in the journal Disease Markers.
Systemic lupus erythematosus (sometimes called lupus for short) is a disease in which the body’s own immune system attacks several organs, with the kidney accounting for the most affected organ. Lupus is about nine times more common in women than in men. Unfortunately, the disease currently has no cure although therapies and diagnosis can improve symptoms and survival. The disease can flare up unexpectedly, leading to frequent costly medical problems. Biomarkers that could help predict flareups would be potentially helpful for preventative treatments.
Javier Perez-Hernandez and Raquel Cortes of INCLIVA Biomedical Research Institute, Valencia, Spain discussed how extracellular vesicles could play a role in systemic lupus erythematosus. Current measurements for lupus are not well-established or simple to measure. Proposed biomarkers include C3 and C4, proteinuria, anti-dsDNA, or creatinine clearance, however these clinical indicators are not specific to lupus and assays to detect them are not always sensitive. The Systemic lupus erythematosus (SLE) Disease Activity Index (SLEDAI) is the most often used method to gauge SLE symptoms. This is a list of 24 items, with sixteen items depending on physician assessments and eight on laboratory tests, including urinalysis, blood complement levels, increased anti-DNA antibody levels, and low platelet and white blood cell counts. A score of 6 or higher means that a person with lupus is in an active disease state.
Extracellular vesicles (EV) are containers found in cells that carry nucleic acids, proteins, and fats. They are crucial for the cells to function properly. In their review, the researchers proposed that extracellular vesicles may be more useful than current biomarkers for assessing disease severity in SLE, specifically because they carry autoantigens and other markers of SLE, known as cytokines. EVs can also indicate whether programmed cell death (apoptosis) is occurring, an event seen in the cells of people with SLE. Researchers further proposed that these vesicles may be used to deliver medications in people with SLE.
In their publication, Perez-Hernandez and Cortes noted “EVs are potential regulators in autoimmune disorders, having a determinant role in the appearance and maintenance of inflammation. In SLE, the defective clearance of apoptotic bodies and their accumulation represents a major source of autoantigens.”
Because EVs are important indicators of immune system function they may be useful as biomarkers in SLE. However, more work needs to be done to understand EVs and their precise role in SLE. “The precise pathophysiological functions of these vesicles and their role as therapeutic agents or targets are not fully understood. Although further studies are necessary, we foresee a great potential for EVs as immunomodulatory agents and therapeutic vehicles in the future”, the authors concluded in their report.