Anaphylatoxin levels in human vitreous humor.
The complement system is involved not only in host defense against infection but also in autoimmune tissue damage. Using a radioimmunoassay, we sought to measure levels of C3a, C4a and C5a (activated complement fragments with anaphylatoxin functions) in human vitreous humor from eyes with and without vitreal inflammation. Vitreous from 11 patients with clinical evidence of vitritis (Group 2) had significantly higher levels of protein, C3a and C4a and significantly higher ratios of these anaphylatoxins to protein than vitreous from 19 patients without clinical evidence of vitritis (Group 1). The finding that not only the absolute levels of anaphylatoxins but also the ratios of anaphylatoxins to protein were significantly higher in vitreous from Group 2 than vitreous from Group 1 or normal plasma suggested that complement activation was taking place in inflamed vitreous. Because of irreversible binding to leukocytes, C5a is difficult to measure and correlate with complement activation, and we were unable to detect it in any vitreous sample.
Mondino
B J
BJ
Department of Ophthalmology and Jules Stein Eye Institute, UCLA School of Medicine 90024.
Sidikaro
Y
Y
Sumner
H
H
D000706:Anaphylatoxins / Q000378:metabolism*; D001798:Blood Proteins / Q000378:metabolism; D003176:Complement C3 / Q000378:metabolism; D015926:Complement C3a; D003181:Complement C4 / Q000378:metabolism; D015934:Complement C4a; D003182:Complement C5 / Q000378:metabolism; D015936:Complement C5a; D009877:Endophthalmitis / Q000209:etiology / Q000378:metabolism; D005136:Eye Proteins / Q000378:metabolism; D006801:Humans; D007239:Infections; D007249:Inflammation / Q000097:blood / Q000378:metabolism; D010455:Peptides / Q000378:metabolism*; D011863:Radioimmunoassay; D012016:Reference Values; D014822:Vitreous Body / Q000378:metabolism*
D000706:Anaphylatoxins; D001798:Blood Proteins; D003176:Complement C3; D003181:Complement C4; D003182:Complement C5; D005136:Eye Proteins; D010455:Peptides; D015926:Complement C3a; D015934:Complement C4a; D015936:Complement C5a