TABLE 1.

Complement protein levels in healthy state in humans and their half-lives.

Protein	MW	Serum concentration a(micromole/L)			Half-life	Half-life references
	(kDa)				(hour)
		Min	Max	Average	Unless specified
C3	185	5.405	8.108	6.486	49–69	Sliwinski and Zvaifler (1972)
C5	190	0.289	0.595	0.395	34.65	Alper and Rosen (1984)
C6	105	0.514	0.686	0.610	30–50 min	Schaller et al. (2008)
C7	92.4	0.530	0.758	0.606	61	Schaller et al. (2008)
C8	151	0.331	0.530	0.364	48	Assumed
C9	71	0.662	0.986	0.845	48	Assumed
FB	93	1.828	2.774	2.151	34.65	Alper and Rosen (1984)
FD	24	0.042	0.083	0.058	0.87	Pascual et al. (1988)
FH	155	1.613	3.639	3.226	6 days	Licht et al. (2005)
FI	88	0.386	0.386	0.386	45	Møller Rasmussen et al. (1988)
FP b	53	0.094	0.283	0.094	73.2	Alper and Rosen (1984)
Vn	70	2.857	5.714	6.786	48	Assumed
Cn	80	3.125	5.250	3.750	48	Assumed

^a“Human Complement Proteins.” https://www.complementtech.com/catalog/human-complement- proteins/ (accessed Jun. 15, 2017).

^bFP, trimer concentration (FPn) = 0.094/3 = 0.031 μmol/L.