Potential Inflammatory Markers Related to the Conversion to Alzheimer’s Disease in Female Patients With Late-Life Depression

• Published in: Biological psychiatry global open science Vol. 4; no. 5; p. 100356
• Main Authors: Pyo, Jee Hyung, Han, Sae Saem, Kim, Min-Ji, Moon, Young Kyung, Lee, Su Jin, Lee, Chaemin, Lee, AhRam, Lim, Shinn-Won, Kim, Doh Kwan
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 01.09.2024; Elsevier
• Subjects: Archival Report; Conversion to Alzheimer disease; Inflammatory cytokine; Longitudinal study; Older patients with depression; Predictive markers; Older patients with depression; Predictive markers; Conversion to Alzheimer disease; Inflammatory cytokine; Longitudinal study
• ISSN: 2667-1743; 2667-1743
• DOI: 10.1016/j.bpsgos.2024.100356

Inflammation 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. A longitudinal study was conducted 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 was used to plot an AD-free survival curve. Among 132 participants, 34 patients with depression (25.76%) developed AD during their follow-up period. Higher levels of interleukin (IL) 1β at baseline (hazard ratio = 3.30 [95% CI, 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. The survival curve plotted by the cutoff value of ≥0.25 pg/mL for IL-1β and ≤0.15 pg/mL for IL-10 suggested adjusted hazard ratios of 8.96 (95% CI, 3.48–23.09; p < .001) for IL-1β and 10.99 (p < .001) for IL-10, respectively. This 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 the transition to AD from depression. Many patients with depression, more than expected, have been observed to be converted to Alzheimer’s disease (AD) in the real world. We investigated potential inflammatory blood surrogate markers regarding progression from depression in late life to AD in 132 older Korean women with depression over a period of 1 to 18 years. Higher levels of the proinflammatory cytokine IL-1β and lower levels of the anti-inflammatory cytokine IL-10 were associated with a higher risk of transition from depression to AD. These findings suggest that these markers could serve to predict the onset of AD in individuals with depression.