title: Allelic variants for complement factors C3, C4, and B in acute necrotizing ulcerative gingivitis.
abstract: Impaired immune defense mechanisms and genetic factors appear to play a role in susceptibility to acute necrotizing ulcerative gingivitis (ANUG). Therefore, possible etiological mechanisms might involve genes at the Major Histocompatibility Complex, which include the complement factor loci. We have tested for a possible association between certain complement factor alleles and ANUG using a case-control study design. Specific alleles at complement factors C3 and C4, and properdin factor B (Bf) loci were determined indirectly by high voltage agarose gel electrophoresis in 58 subjects with a history of ANUG and in 58 age-sex-matched healthy controls. The highest relative risk of ANUG, as obtained by conditional logistic regression, for alleles at the C3 locus was 1.9 (90% confidence limits 0.8 to 4.8; p = 0.229) for C3*F-positive individuals. The highest relative risk for alleles at the C4 locus was 2.6 (0.5 to 14.9; p = 0.358) for C4A*3-positive individuals. There was no evidence for an association between Bf allotype and risk of ANUG, with a relative risk of 1.2 for Bf*F- and relative risk of 1.0 for B*S-positive individuals. None of our estimates was statistically significant. We conclude, therefore, that it is unlikely that there is any association between complement factor gene haplotype and susceptibility to ANUG.
authors.affiliation: Department of Epidemiology, School of Public Health, University of Alabama, Birmingham 35294.
authors.forename: S L
authors.initials: SL
authors.lastname: Melnick
authors.forename: R C
authors.initials: RC
authors.lastname: Go
authors.forename: R B
authors.initials: RB
authors.lastname: Cogen
authors.forename: J M
authors.initials: JM
authors.lastname: Roseman
mesh_terms: D000208:Acute Disease; D000483:Alleles; D003176:Complement C3 / Q000235:genetics*; D003181:Complement C4 / Q000235:genetics*; D011415:Complement Factor B / Q000235:genetics*; D004792:Enzyme Precursors / Q000235:genetics*; D005787:Gene Frequency; D014644:Genetic Variation; D005892:Gingivitis, Necrotizing Ulcerative / Q000235:genetics* / Q000276:immunology; D006801:Humans; D010641:Phenotype
chemical_list: D003176:Complement C3; D003181:Complement C4; D004792:Enzyme Precursors; D011415:Complement Factor B