Relationships between thehaemolytic activities ofthehuman complement system andcomplement components

Therewasa good correlation between CH50and AP50. AP50had a good correlation with BandCV50.TherewasnocorrelationbetweenAP50andC(3-9)H50,andnonebetweenC(3-9)H50and C5or C9.AP50mayprimarilyrepresentchanges in the early partofthealternative pathway. C(3-9)H50is not influenced by respective changes in the amounts ofC5 or C9. Since cell lesion is nowconsidered to becausedbyaunitofC5bto C9,achangein eachcomponentofC5to C9maynotinfluence haemolyticactivity.INTRODUCTIONThecomplementsystemis classified into twopathways, the classical andthe alternative. SincePillemeretal. (1954)introducedtheproperdinsystemasahumoral