INFLUENCE OF SMOKING AND RACE ON IMMUNOGLOBULIN-G SUBCLASS CONCENTRATIONS IN EARLY-ONSET PERIODONTITIS PATIENTS

Recent data indicate that smoking is an important risk factor for the development of periodontitis. Smoking is also known to reduce serum im munoglobulin G (IgG) levels. Interestingly, patients with the localize d form of early-onset periodontitis (LJP) have elevated levels of seru m IgG2, and those who smoke are not clinically different from nonsmoki ng LJP subjects. In contrast, patients with the generalized form of ea rly-onset periodontitis (G-EOP) who smoke have more extensive destruct ion than their nonsmoking counterparts. Given the effects of smoking o n EOP and the association of IgG2 with less severe disease, we hypothe sized that smoking might reduce serum IgG2 and that this might be most apparent in G-EOP. We therefore examined the effects of smoking on se rum IgG subclass concentrations in race-matched groups: LJP, G-EOP, an d age-matched periodontally healthy controls (NPs). Smoking status was established from serum cotinine levels, and serum IgG subclass concen trations were determined by using radial immunodiffusion. The data ind icated that the effects of smoking were remarkably selective with resp ect to both IgG subclass and race. Smoking did not appear to have any effect on the concentration of IgG1 or IgG3 in either black or white s ubjects. In contrast, smoking was associated with depressed serum IgG2 concentrations in both white NP and G-EOP subgroups. Serum IgG2 level s in black subjects did not appear to be depressed by smoking, with th e single striking exception of the black G-EOP subgroup which also had depressed serum IgG4 levels. The results here confirm that smoking ha s effects on serum immunoglobulin levels, but the effects were both ra ce and serum IgG subclass specific. Furthermore, the periodontal diagn osis of EOP subjects appeared to be important, as indicated by the fac t that IgG2 and IgG4 levels were reduced in smoking black G-EOP subjec ts whereas the IgG2 and IgG3 levels in black LJP and NP subjects were not reduced by smoking.