Low innate production of interleukin-1β and interleukin-6 is associated with the absence of osteoarthritis in old age

SummaryObjectiveWe investigated whether innate differences in cytokine response were associated with the absence of osteoarthritis (OA) in old age.DesignIn 82 participants from a cross-sectional birth cohort, radiographs of hands, hips and knees were taken at the age of 90 years. OA was defined as a Kellgren–Lawrence score of at least two. “Free from OA” was defined at patient level as absence of hip and knee OA, and presence of OA in maximally two hand joints. The innate cytokine response was determined in whole-blood samples upon stimulation with lipopolysaccharide. Logistic regression analyses were used to investigate associations between absence of OA in relation to tertiles of interleukin (IL)-1β, IL-6, tumor necrosis factor (TNF)-α, IL-1 receptor antagonist (RA) and IL-10. Adjustments were made for gender and body mass index.ResultsSixteen percent of the participants were “free from OA”. Subjects in the lowest tertile of Il-1β production had a 11-fold increased chance to be free of OA [odds ratio (OR) 11.3, confidence intervals (CI) 95% 1.1–115.9], subjects in the lowest tertile of IL-6 production had an almost 7-fold increased chance to be free of OA (OR 6.7, 95% CI 1.1–41.2). Absence of hand OA was associated with low innate production of IL-6 and IL-1RA, absence of hip OA was associated with low innate IL-1β production. No associations were found for TNF-α and IL-10.ConclusionsLow innate capacity to produce the pro-inflammatory cytokines IL-1β and IL-6 is associated with the absence of OA in old age.