Finberg R, Barland P, Grayzel A I
Am J Clin Pathol. 1977 Jan;67(1):97-9. doi: 10.1093/ajcp/67.1.97.
Total hemolytic complement activity (CH50) and levels of C4, C5, and Factor B determined by commercially available radial immunodiffusion plates were compared in sera from patients with systemic lupus erythematosus. There was a significant correlation between CH50, C4 and C5, but no correlation between Factor B and any of the other indices of complement activity measured.