Depletion of C2 and C4 in Sera from Hamsters Bearing Herpes Simplex Type 2-Induced Tumors

Total hemolytic complement activity (CH₅₀) was compared in sera from normal and tumor-bearing hamsters. CH₅₀ ranged from 160 to 216 in normal animals and from 82 to 152 in tumor-bearing animals. Preliminary screening assays indicated that of 9 complement components assayed, only C2 and C4 showed differences in titer in both normal and tumor-bearer sera. In an expanded study, examination of sera from 12 normal and 14 tumor-bearing hamsters showed that the mean C4 and C2 levels were approximately 88 and 70% below those seen in normal sera, respectively.