IL18 and Alzheimer disease: In the pooled group of patients (SMC, MCI, and AD), correlation analysis showed a significant negative correlation between the MMSE scores and IL-18 (r = − 0.223, p = 0.004), sIL-1R1 (r = − 0.583, p < 0.001), sIL-1R4 (r = − 0.489, p < 0.001), IL-18BP (r = − 0.663, p < 0.001), sIL-1R3 (r = − 0.359, p < 0.001), and IL-33 (rs = − 0.333, p < 0.001).