Table 2. Characteristics of patient and control study population used to measure plasma sTREM2.

Data are expressed as number of patients (percent), mean ± SD, or median (IQR) as appropriate. Probability values (P) denote differences between control, AD, and FTD patient groups. χ2 tests were used for gender. One-way ANOVA was used to compare age between groups followed by Tukey post hoc test. CSF biomarkers and sTREM2 were evaluated by nonparametric statistical analysis (Kruskal-Wallis and post hoc with Mann-Whitney U test).

VariableTotal (n = 172)Controls (n = 86)AD (n = 51)FTD (n = 35)P
Gender (F/M), no. (%)103 (60)/69 (40)55 (64)/31 (36)36 (71)/15 (29)12 (34)/23 (66)0.002*
Age, years (mean ± SD)64.1 ± 10.160.4 ± 9.570.7 ± 9.063.7 ± 8.4<0.001
CSF biomarkers
  Aβ1–42 (pg/ml), median (IQR)626.3 (453–813)780.8 (645–902)398.5 (301–508)588.0 (478–824)<0.001
  T-tau (pg/ml), median (IQR)244.4 (172–486)202.8 (157–244)675.0 (498–891)230.1 (148–345)<0.001§
  P-tau181P (pg/ml), median (IQR)46.5 (36–74)40.0 (34–49)89.9 (73–103)40.0 (28–53)<0.001
sTREM2 (relative units)
  Median (IQR)1.022 (0.703–1.590)1.022 (0.675–1.864)0.998 (0.702–1.375)1.046 (0.759–1.399)0.872

*Post hoc significances for gender: controls versus AD, P = 0.427; controls versus FTD, P = 0.003; AD versus FTD, P = 0.001.

†Post hoc significances for age: controls versus AD, P < 0.001; controls versus FTD, P = 0.165; AD versus FTD, P = 0.002.

‡Post hoc significances for Aβ1–42: controls versus AD, P < 0.001; controls versus FTD, P < 0.001; AD versus FTD, P < 0.001.

§Post hoc significances for T-tau: controls versus AD, P < 0.001; controls versus FTD, P = 0.054; AD versus FTD, P < 0.001.

¶Post hoc significances for P-tau181P: controls versus AD, P < 0.001; controls versus FTD, P = 0.704; AD versus FTD, P < 0.001.