Complement Activity in Sera from Normal Adult Blood Donors: Its Relation to Blood Group, Rh*** (D) Type, Sex, Age and Weight

Abstract

Serum samples from 1,258 normal adult blood donors were assayed for complement activity. The average complement titer for the entire sample was 38.14. There was no difference in complement activity with respect to sex, blood group or Rh***(D) type. The level of circulating complement appears to be higher in older humans and in heavier individuals. In this kind of experimentation, the need for a standard complement for assay of different batches of sheep erythrocytes is emphasized.

Complement and Complement Component Activities in Diseases Associated with Repeated Infections and Malignancy

“…The child hood norm was reached by age two years, and a further increase was seen between childhood and adult life. These observations agree with most but not all previous investigators (7,12,13,16,17,31,34,37,39,68,69). Of particular interest, titers of C'l were dispropor tionately low in the newly born, a finding not apparent when C'l was measured by the reagent assay method (17,34).…”

Serum Complement Activity during Normal Pregnancy

“…This figure compares favorably with that reported by Baltch et al, 3 i.e. 31.4, but is slightly lower than that reported by Marucci and Chapman, 13 i.e. 37.92 CH 50 units/ml.…”