SALIVARY SPECIFIC IGG IS A SENSITIVE INDICATOR OF THE HUMORAL IMMUNE-RESPONSE TO HELICOBACTER-PYLORI

In humans, salivary antibodies are secreted during humoral immune resp onse. Helicobacter pylori infection is associated with systemic humora l immune response reflected by raised serum levels of specific IgG. Th e present study was aimed at exploring whether salivary concentrations of specific H. pylori IgG are a reliable indicator of H. pylori infec tion. Serum and salivary samples were obtained from 291 subjects atten ding the GI clinic and tested for H. pylori-specific IgG by a direct E LISA (94% sensitivity, 95% specificity for serum determinations) using a crude H. pylori sonicate as antigen. Data are given as optical dens ity (mean +/- S.D.). Levels of salivary H. pylori IgG paralleled those of circulating specific IgG in the 291 subjects studied (0.981 +/- 0. 431 vs. 0.777 +/- 0.682, respectively). A significant positive correla tion was found between specific H. pylori IgG in sera and saliva sampl es (r = 0.981, P < 0.0001). An overall concordance between circulating and salivary H. pylori IgG was observed in 238 out of the 291 (81.7%) subjects. Salivary H. pylori IgG represent a sensitive marker of spec ific humoral immune response and they may substitute circulating H. py lori IgG measurement when sera samples are not available.