Objective: To examine the association of peripheral blood mononuclear cell (PBMC) derived interleukin 1beta (IL-1beta), IL-1 receptor antagonist (IL-1Ra), tumor necrosis factor alpha (TNF-alpha), and radiographic osteoarthritis (OA) in the elderly.
Methods: A total of 703 subjects (436 women, 267 men, mean age 78.5+/-4.5 yrs) had both knee and hand radiographs, and cytokines were measured during the 22nd biennial examination of the Framingham Cohort. PBMC derived IL-1beta , IL-1Ra, and TNF-alpha production was assessed using a non-cross reacting polyclonal radioimmunoassay. Knee OA was defined as a score of > 2 using a modified Kellgren and Lawrence scale. The presence of osteophytes and joint space narrowing were scored separately on a 0-3 scale, in which disease was defined a priori as a score > 0 for each feature. Sex-specific odds ratios were calculated for knee OA after adjusting for weight, history of knee injury, and use of estrogen and nonsteroidal antiinflammatory drugs.
Result: No uniform associations were found for IL-1beta or IL-1Ra in men, or for TNF-alpha production and radiographic OA in either sex. We found possible associations for the highest levels of IL-1beta production and the presence of knee osteophytes [OR=2.0 (1.2-3.5)] and joint space narrowing [OR=1.7 (1.1-2.8)] in women. Our data suggested a possible protective effect for IL-1Ra production and hand OA in women [OR=0.6 (0.4-1.0)].
Conclusion: We found no consistent association of PBMC cytokine production and radiographic OA. However, women with the highest production of IL-1beta and IL-1Ra had respectively higher rates of knee OA and lower rates of hand OA than expected.