Researchers believe rheumatoid arthritis may be two different diseases

Is rheumatoid arthritis (RA) two different diseases? That’s the question on everyone’s lips after Dutch researchers claimed RA, a common form of arthritis, may in fact be two different diseases, one with and one without autoantibodies (a group of antibodies).

While the chronic inflammatory disorder improves over time for most patients, long-term outcomes only improve in RA patients with autoantibodies, according to a new study published this week in PLOS Medicine. The study’s authors said the findings add to a growing body of evidence that suggest RA with or without autoantibodies are two distinct conditions.

In the new study, researchers followed 1,285 RA patients between 1993 and 2016. In total, 823 patients had autoantibodies and 462 patients did not. In both groups, disease activity decreased significantly over time.

However, the researchers found that sustained drug-free remission rates increased in RA patients with autoantibodies, but not in patients without. Moreover, mortality and functional disability decreased in patients with autoantibodies.

“The disconnection between improvement in disease activity and subsequent improvement in long-term outcomes in RA without autoantibodies suggests that the underlying pathogenesis of RA with and without autoantibodies is different,” the study’s authors said.

“We propose that it is time to formally divide RA into type 1, with autoantibodies, and type 2, without autoantibodies, in the hope that it leads to stratified treatment in autoantibody-positive and autoantibody-negative RA.”

Meanwhile, lead author Dr Xanthe Matthijssen added: “In the last decennia research in RA has largely focused on the autoantibody-positive subset. More research on autoantibody-negative RA is urgently needed to identify methods to also improve their long-term outcome.”

Around 450,000 Australians are currently living with RA, a condition that can affect anyone at any age and may cause significant pain and disability. RA typically begins in the smaller joints of the hands, wrists and feet. If not appropriately managed, ongoing inflammation can lead to irreversible joint damage and loss of function.

The research comes just a few days after a study suggested glucocorticoids (a group of drugs), which are commonly prescribed to RA patients thanks to their powerful anti-inflammatory properties, are linked to a higher risk of infection.

The team analysed 200,000 patients with RA and found patients who received a higher dose (more than 10mg per day) had more than twice the risk of serious infection, compared to those not receiving the steroids. Additionally, patients receiving the lowest dose had close to a 30 per cent increased risk of infection.

IMPORTANT LEGAL INFO This article is of a general nature and FYI only, because it doesn’t take into account your personal health requirements or existing medical conditions. That means it’s not personalised health advice and shouldn’t be relied upon as if it is. Before making a health-related decision, you should work out if the info is appropriate for your situation and get professional medical advice.