Is rheumatoid arthritis catching you unawares? Your body might be warning you ahead of time. Well, a very small part of your body. Specifically, one cell.

A study published in The New England Journal of Medicine discovered a new cell that appears in large quantities ahead of a rheumatoid arthritis flare-up.

Rheumatoid arthritis is an autoimmune disease where an individual’s body self-sabotages by attacking its own cells. This causes joints, like wrists, elbows and knees, to become inflamed and swell. People can also experience chronic pain and have difficulty balancing.

Although symptoms can be minimal, individuals with rheumatoid arthritis can also experience periods where the inflammation and consequent symptoms become more intense, typically referred to as a flare-up.

Prior to this study, it was difficult to predict when a flare-up could occur, making the condition challenging to manage on days when typical functioning was impaired.

Researchers used participants’ blood samples to analyze RNA, a messenger that controls our DNA’s protein synthesis. The study monitored changes to the RNA of participants with rheumatoid arthritis over a long period of time, identifying a marker of an unknown cell that appeared in high numbers before a flare-up, and almost none during one.

Researchers named these new “warning” cells PRIME cells, speculating they may hold the key to future methods of monitoring and managing everyday life for those with rheumatoid arthritis.

Better preparation for a flare-up would give a person time to prepare for a bout of crippling inflammation and pain, or at least do what they can to make the episode less disruptive.