BackgroundInflammation has been postulated as a mediating factor in the development of Alzheimer’s disease (AD) pathology. We investigated candidate inflammatory markers related to conversion to AD among patients with depression. MethodsA longitudinal study was performed with older women with depression who were at least 55 years of age, with a mean follow-up period of 5.73 years. At baseline, 9 inflammatory cytokines were measured using the immunoreactivity method. During follow-up, patients with depression who complained of cognitive impairment were evaluated and diagnosed with AD conversion. Association of the cytokines with conversion to AD was analyzed using multivariable Cox proportional hazards regression with adjusting covariates. For clinical applicability, the optimal cutoff value was determined using the minimum p value approach for the conversion to AD and the plotted AD-free survival curve. ResultsAmong 132 participants, 34 patients with depression (25.76%) developed AD during their follow-up period. It showed that higher levels of interleukin (IL) 1β at baseline (hazard ratio [95% CI] = 3.30 [1.11–9.78], p = .031) and lower levels of IL-10 (p = .001) were significantly associated with an increased risk of progression to AD. Survival curve by plotting a cutoff value of ≥0.25 pg/mL for IL-1β and ≤0.15 pg/mL for IL-10 suggested adjusted hazard ratio of 8.96 (95% CI, 3.48–23.09; p < .001) for IL-1β and 10.99 (p < .001) for IL-10, respectively. ConclusionsThis study demonstrated that IL-1β and IL-10 were associated with conversion to AD among patients with late-life depression, suggesting their potential as predictive markers of transition to AD from depression.