Senescent-like B cells drive rheumatoid arthritis before diagnosis

An international team analysed blood cells from people at risk of rheumatoid arthritis who had not yet developed the disease. The study, published in Nature Aging, used single-cell multiomics: a technique that simultaneously measures gene activity, protein production and other characteristics of individual cells. The researchers found a marked expansion of a specific type of B cell, a white blood cell that normally produces antibodies.

The B cells identified showed features resembling cellular senescence: they were active, but behaving abnormally. They produced antibodies that react to multiple targets at once, including the body’s own proteins. That is problematic because it means the immune system is effectively attacking itself. These cells also activated T cells, another type of immune cell, by presenting self-antigens to them.

Senescence in the immune system

Cellular senescence is a state in which cells stop dividing but remain active and continue sending out signals. In this case, the affected cells are not tissue cells but immune cells themselves. That is a relatively new insight: the aging process does not only unfold in organs, but also within the immune system.

The finding suggests that these senescent-like B cells may play a role in the transition from risk to disease. Whether they actually cause the disease or are more likely a consequence of early inflammation has not yet been definitively established.

Early intervention as a prospect

If senescent-like B cells are indeed an early step in the development of rheumatoid arthritis, they represent a potential target for prevention. The researchers emphasise that the study is observational. Moving toward treatment requires further research. Even so, it is notable for longevity science that immune cell senescence appears to precede a disease long not considered an aging disease.

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