GFAP and chronic kidney disease: Plasma concentrations (median [IQR]) of NfL (37.5 [22.1–47.5] vs. 13.4 [10.5–16.7] ng/L, p < 0.001), p-Tau231 (25.7 [19.1–38.7] vs. 13.9 [10.5–16.3] ng/L, p < 0.001) and GFAP (190 [140–281] vs. 153 [116–211] ng/L, p < 0.001) were elevated in patients with CKD compared with controls.