Kruisbergen NNL, van Gemert Y, Walgreen B, et al. - Experts aspired to explore whether early treatment with a single dose of IL-1β blocking antibodies could prevent Western diet (WD) induced changes to systemic monocyte populations and their cytokine secretion profile, and thus modulate collagenase induced osteoarthritis (CiOA) pathology. CiOA was induced in female C57Bl/6 mice fed either a standard diet (SD) or WD and given a single dose of either polyclonal anti-IL-1β antibodies or control. WD feeding of C57Bl/6 mice resulted in increased serum levels of low-density lipoprotein and innate immune activation in the form of an increased number of Ly6C ^high cells in bone marrow and blood, as well as increased cytokine expression by bone marrow cells, particularly IL-6 and TNF-α. The single-dose systemic anti-IL-1β treatment prevented WD-induced innate immune activation during early-stage CiOA in C57Bl/6 mice but did not improve joint pathology.