THE EFFECT OF SMOKING ON SERUM IGG2 REACTIVE WITH ACTINOBACILLUS-ACTINOMYCETEMCOMITANS IN EARLY-ONSET PERIODONTITIS PATIENTS

HIGH TITERS OF SERUM IgG2 reactive with Actinobacillus actinomycetemco mitans ? are present in early-onset periodontitis (EOP) patients and i t appears that anti-A. actinomycetemcomitans may be protective. Smokin g is associated with increased periodontal disease severity in general ized early-onset periodontitis (G-EOP) patients, but is not associated with periodontal disease severity in patients with localized juvenile periodontitis (LJP). Furthermore, smoking is associated with reduced serum IgG2 levels in black patients with G-EOP but not in those with L JP. Based on this selective effect of smoking, we hypothesized that sm oking would be associated with a reduction of specific IgG2 reactive w ith A. actinomycetemcomitans ?? in black G-EOP patients but not black LJP patients, In addition, we examined IgG2 responses to carbohydrate antigens from non-periodontal pathogens including Haemophilus influenz ae b oligosaccharide antigen (Hib) and the Streptococcus pneumoniae an tigen phosphocholine (PC). Smoking status was assessed from serum coti nine levels, and IgG2 specific for A. actinomycetemcomitans, Hib, and PC was assessed by ELISA. Our study revealed that smoking was correlat ed with a dramatic reduction in serum IgG2 anti-A. actinomycetemcomita ns in G-EOP smokers but not in LJP smokers. In contrast, anti-Hib IgG2 and anti-PC IgG2 were not affected in either G-EOP or LJP patients. I n short, these results indicate that smoking is associated with a redu ction in serum IgG2 anti-A. actinomycetemcomitans in black G-EOP subje cts, but IgG2 reactive with other antigens may not be reduced in G-EOP smokers.