Rheumatoid arthritis is an autoimmune disorder that causes inflammation, swelling and pain in joints. It can have a range of impacts, and as of 2019, was thought to impact about 18 million people worldwide. New research has suggested that signs of immune aging are evident in the early stages of the disease, before patients are diagnosed. If this research eventually leads to a test that can be applied in the clinic, it could be very beneficial to those who are at risk of RA. It may help clinicians apply preventive measures earlier, and possibly halt the development of serious RA. The findings have been reported in eBioMedicine.
This study involved 224 RA patients in various stages of disease. The investigators determined that people experiencing joint pain or who have undifferentiated arthritis show signs of premature aging in their immune systems. People with signs of immune aging were more likely to be diagnosed with RA than those who did not. Immune aging could be directly related to RA, the study suggested.
"We've discovered that immune aging isn't just a consequence of rheumatoid arthritis—it may be a driver of the disease itself," said senior study author Dr. Niharika Duggal, an Associate Professor at the University of Birmingham. "We found that people in the early stages of rheumatoid arthritis, i.e. before a clinical diagnosis, show signs of faster immune system aging.”
Immune aging was seen in the thymus, an organ that helps immune cells mature. Thymic output was reduced, and there were fewer mature T cells in individuals with immune aging who also had joint problems. There were also more immune cells that had stopped dividing, or senescent cells, and higher levels of inflammatory molecules such as CRP, IL-6, and TNFα in those with immune aging.
The immune aging score (IMM-AGE) developed in this study could reveal immune aging in people prior to an RA diagnosis.
"These findings suggest we might be able to intercept the disease development in at-risk individuals and prevent it from developing by using treatments that slow aging, such as boosting the body's natural process for clearing out damaged cells,” added Duggal.
Signs off advanced immune aging, like inflammatory Th17 cells arose after RA was fully developed.
The researchers suggested that aging pathways may offer a new treatment or prevention option for RA, but more research will be needed to determine if that is true, and then find drugs that fit the bill.
Sources: University of Birmingham, eBioMedicine
