TABLE 1.

Detailed characteristics of studies included in our review

Authors	Year of publication	Study site	Study design	Number (patients/controls)	Age (patients/controls)	Sample source	CRP subtypes with cut‐off value	CRP assay type	Main outcomes/end point assessment
Keizman et al. (2009)	2009	Israel	Case–control	80/80	59 ± 19 years (range 25−88)	Serum	Wide‐range C‐reactive protein (0‐5 mg/L)	NA	ALS functional rating scale (ALSFRS‐R)
Ryberg et al. (2010)	2010	USA	Case–control	100/41	52.6/44.9 years	CSF	C‐reactive protein	ELISA	Mass spectral peaks, concentration of CRP levels
Miller et al. (2015)	2015	USA	RCT	94(NP001)/42(placebo)	54.4 (12.4)/53.7 (9.52) years	Plasma	Wide‐range C‐reactive protein (wr‐CRP)	NA	ALSFRS‐R, vital capacity
Nagel et al. (2017)	2017	Germany	Case–control	289/506	65.7 (10.5) years/66.3 (9.8) years	Serum	hs‐CRP (mg/L)	Latex‐enhanced high‐sensitivity immunonephelometry assay	Concentration of hs‐CRP, mortality/survival status
Lunetta et al. (2017)	2017	Italy	Cohort	394	60.18 (13.60) years	Serum	CRP (≤0.20 mg/dl)	NA	ALSFRS‐R, survival status,
Beers et al. (2020)	2020	USA	Cohort (first group)	68/55	58.8 (1.57)/57.6 (2.15) years	Serum	C‐reactive protein	ELISA	Appel ALS (AALS) score
			Cohort (second group)	100/60	62.6 (1.47)/63.5 (1.15)	Serum	C‐reactive protein	ELISA	Appel ALS (AALS) score
Chełstowska & Kuźma‐Kozakiewicz (2020)	2020	Poland	Cohort	203	mean: 56 years; median:57 years	Serum	C‐reactive protein	NA	Concentration of CRP levels, ALSFRS‐R
Cui et al. (2020)	2020	Sweden	Case–control	525/2625	65.90 ± 13.10/65.87 ± 13.09 years	Serum	High‐sensitivity C‐reactive protein	Behring nephelometer and reagent	Change in CRP levels
De Schaepdryver et al. (2020)	2020	Belgium, Italy	Cohort	383	NA	Serum	C‐reactive protein		ALSFRS‐R and survival status
Huang et al. (2020)	2020	USA	Case–control	108/79		Plasma, CSF	C‐reactive protein	MSD (Meso Scale Discovery) V‐Plex	Disease progression ALSFRS‐R, slow vital capacity
Sun et al. (2020)	2020	Sweden	Cohort	399	66.25 years	Serum	hs‐CRP (mg/L)	NA	Mortality risk