Different HLA antigen associations for the functionally active and inactive products of the complement C4F1 allele

Geoffrey J. O'Neill, Peggy Miniter, Marilyn S. Pollack, Bo Dupont

Research output: Contribution to journalArticlepeer-review

26 Scopus citations


The genetic polymorphism of the fourth component of human complement. C4, was studied in 945 unrelated Caucasian individuals. A third allele of the C4F (Rodgers) locus, termed C4F1 was demonstrated. This allele is characterized using immunofixation electrophoresis, by the presence of an additional fast-moving anodal band of C4 which distinguishes it clearly from the common C4F variant. The allelic frequencies fit the Hardy-Weinberg equilibrium assuming three alleles at the C4F locus: C4F, C4f0, and C4F1. The functional activity of the C4F variants was investigated using a specific hemolytic overlay technique for C4. It was found that in almost all individuals (75 out of 78), the C4F1 allele codes for a functionally inactive C4 product only when it occurs on an HLA-B17 positive haplotype but that the same allele codes for a functionally active fast variant of C4 when it occurs on an HLA-B37 positive haplotype (18 out of 18). Very strong genetic linkage disequilibrium was observed for the C4F1 allele with HLA-B17 and B37. The active and inactive C4F1 variant also has marked nonrandom gametic association to different alleles of the of locus and to HLA-C locus determinants. No further variants of the C4S (Chido) locus have been identified so far. Rodgers (Rg) typing by the plasma inhibition test of anti-Rg antiserum has shown that plasma from individuals homozygous for the C4F1 allele is only able to partially inhibit anti-Rg whereas all C4F positive individuals totally inhibited the reaction.

Original languageEnglish (US)
Pages (from-to)23-30
Number of pages8
JournalHuman Immunology
Issue number1
StatePublished - Jul 1980
Externally publishedYes

ASJC Scopus subject areas

  • Immunology and Allergy
  • Immunology


Dive into the research topics of 'Different HLA antigen associations for the functionally active and inactive products of the complement C4F1 allele'. Together they form a unique fingerprint.

Cite this