Immune Function Has Key Role in OA

Monocytes influence pain and disease progression

Monocyte activation plays a pivotal role in the degree of pain and disease progression associated with osteoarthritis (OA), according to Canadian researchers.

Monocytes were more activated and pro-inflammatory in women with OA, and that elevated inflammation and BMI were associated with this increased activation, reported Dawn Bowdish, PhD, of McMaster University and McMaster Institute for Research on Aging in Hamilton, Ontario, Canada, and colleagues, in Osteoarthritis and Cartilage.

The study included 22 women with OA, and 22 healthy age- and sex-matched controls. The researchers measured markers of soluble and cellular inflammation in the peripheral blood.

Serum C-reactive protein (CRP) levels were elevated in participants with OA, who also had a lower proportion of circulating monocytes. Increased expression of the activation markers CD16, CCR2, and HLA-DR was found in monocytes from women with OA; these monocytes induced greater production of tumor necrosis factor (TNF) and interleukin-1β than in healthy controls. BMI and higher serum TNF levels were correlated with increased monocyte expression of CCR2.

“It is the first study, to our knowledge, to specifically characterize changes in circulating monocytes in individuals with OA compared to healthy women,” said Bowdish. “We know that changes in monocytes contribute to the development of chronic inflammatory conditions. If we can target these monocytes in OA, we may be able to slow down disease progression or decrease the risk of other chronic inflammatory diseases.”