Research May Identify Psoriasis Patients at Risk for Psoriatic Arthritis

Genetic variants found that are associated with psoriatic arthritis, but not psoriasis.

Researchers may have discovered a genetic process that will allow physicians to test psoriasis patients at high risk for developing psoriatic arthritis (PsA).

Most PsA patients have skin psoriasis, which is present prior to the development of arthritis, but only one-third of psoriasis patients go on to develop PsA. In a study conducted by the Arthritis Research UK Centre for Genetics and Genomics at The University of Manchester, researchers identified genetic variants associated with PsA but not with psoriasis, which shows that genetic changes increase the risk of PsA but not psoriasis.

Prior to the study, opinions varied as to whether PsA is its own unique disease or if the condition is a result of psoriasis combined with rheumatoid arthritis, the researchers noted. The findings of the current study may allow physicians to identify psoriasis patients at risk of developing psoriatic arthritis.

"Our study is beginning to reveal key insights into the genetics of PsA that explain fundamental differences between psoriasis and PsA,” lead researcher John Bowes, MD, said in a press release. “Our findings also highlight that CD8+ cells are likely to be the key drivers of inflammation in PsA. This will help us to focus on how the genetic changes act in those immune cells to cause disease."

Researchers identified the HLA-B27 gene located on chromosome 5 that, while not the first PsA-specific gene to be found, indicates that patients who carry this gene are more likely to develop PsA.

"By identifying genes that predispose people to PsA but not psoriasis, we hope in the future to be able to test patients with psoriasis to find those at high risk of developing PsA,” senior author Anne Barton said in a press release. “Excitingly, it raises the possibility of introducing treatments to prevent the development of PsA in those individuals in the future."