Table 2.

PCA of CSF AD and inflammatory proteins in ADNI and two replication cohorts B and C, with loading values of proteins consistently associated with two or more PCs shown.

		ADNI			Cohort B	Cohort C
		NC (n = 85)	MCI (n = 129)	AD (n = 68)	NC, MCI, AD (n = 68)	NC (n = 47)
PC1	t-Taua	0.724	0.871	0.831	0.577	0.734
	p-Tau181a	0.805	0.866	0.826	0.474	0.727
	Aβ42a	−0.752	−0.745	−0.612	−0.781	−0.595
	t-Tau/Aβ42a	0.710	0.675	0.774	0.923	0.925
PC2	sTNFR1a	0.869	0.903	0.884	0.895	0.851
	sTNRF2a	0.784	0.883	0.881	0.859	0.850
	sVCAM1a	0.833	0.869	0.813	0.833	0.825
	TGFβ1a	0.533	0.469	0.561	N.D.	N.D.
	sICAM1a	0.502	0.467	0.661
	IP-10			0.484	0.602	N.D.
PC3	MSD-sTREM2a	0.876	0.883	0.876	0.639b	0.787b
	WU-sTREM2a	0.830	0.882	0.819
	Progranulin	0.519		0.640	N.D.	N.D.
PC4	IL-6a	0.811	0.799	0.828	N.D.	N.D.
	IL-10a	0.691	0.662	0.713	0.922	0.812
PC5	TGFβ2a	0.885	0.820	0.754	N.D.	N.D.
	TGFβ1a	0.598	0.716	0.752	N.D.	N.D.
	TGFβ3		0.538	0.705	N.D.	N.D.
PC6	IL-7a	0.866	0.810	0.797	0.912	0.942
	TNF-αa	0.753	0.429	0.707	0.757
	IL-9		0.601	0.647
PC7	IP-10	0.722	0.705			N.D.
	IL12-p40	0.686	0.772		N.D.	N.D.
	IL-9	0.571			0.865
PC8	IL-21	0.458	0.904		N.D.	N.D.
	sICAM1		−0.624		0.934

^aProteins found in the same PC across ADNI diagnostic groups. Levels of IL-6, IL-12p40, IL-21, progranulin, and TGFβ1/2/3 were not measured in either replication cohort, and IP-10 was not measured in Cohort C.

^bDifferent sTREM2 assays used between ADNI and the replication cohorts.