What are we talking about when we say “biomarker” in immune-mediated diseases, and why are these important?
In the simplest terms, a “biomarker” is any measurable indicator of a biological process. In immune-mediated diseases, one major reason we look at biomarkers is because they can help us identify patients and tell us something about their potential future disease progression.
Take rheumatoid arthritis (RA), for example, an immune-mediated disease that causes joint damage with chronic pain, stiffness and swelling of joints. The effects of RA extend beyond the musculoskeletal symptoms of chronic pain and physical disability, with the potential to include: fatigue, anxiety, depression, respiratory, gastrointestinal, and cardiovascular disease, economic burden, reduced quality of life, and increased mortality.
RA can present and behave very differently in different individuals. Some people with rheumatoid arthritis have a more highly active and progressive form of the disease that can lead to worse outcomes, making an early diagnosis and treatment particularly critical. It was discovered a number of years ago that these patients frequently test positive for a biomarker called anti-citrullinated protein antibody, or ACPA. ACPA can be detected in a person’s bloodstream before joint damage becomes clinically apparent. Knowing that a patient is ACPA positive can therefore give the physician (and the patient) helpful, predictive information right from the start.
Bristol Myers Squibb research has advanced understanding of the impact of ACPA positivity in RA and continues to investigate the correlation between this biomarker and outcomes like joint erosion.