activation of complement with zymosan induced higher mean levels of the anaphylatoxin c3a in hla-b27 positive sera ( mean ( sd ) 7.40 ( 1.66 ) mg/l ) than in hla-b27 negative sera ( 6.41 ( 1.79 ) mg/l ) .
C0009528
activation
C1332656
anaphylatoxin c3a