Changes in gingival crevicular fluid levels of immunoglobulin A following therapy: Association with attachment loss

Background: In previous studies, we demonstrated that increased levels of i mmunoglobulin A (IgA) in gingival crevicular fluid (GCF) may be "protective ," while increased levels of the polymorphonuclear lysosomal enzyme, beta-g lucuronidase, in GCF were associated with increased risk of disease activit y. In this study, we examined the effect of scaling and root planing (SRP) on the levels of beta-glucuronidase, IgG, and IgA in GCF over a 24-week per iod and compared these to clinical attachment loss (CAL). Methods: Twenty-nine patients with periodontal disease were examined for at tachment level, probing depth, plaque, and bleeding on probing at 6 sites p er tooth. GCF was collected from the mesial aspect of all teeth excluding t hird molars and analyzed for beta-glucuronidase, IgG, and IgA. After baseli ne data were collected, each patient received SRP, and GCF was collected ag ain at 2, 4, 6, 8, 12, and 24 weeks post-SRP while clinical data were obtai ned at 4, 8, 12, and 24 weeks. In addition, we analyzed whether the magnitu de of the IgA response to SRP would affect the rate of periodontal disease progression by examining GCF IgA levels at 2 time intervals: 2 to 4 weeks p ost-SRP and 6 to 12 weeks post-SRP. Results: Seventeen patients (58.6%) exhibited at least 1 site losing greate r than or equal to 2.5 mm of CAL during the 24-week study. beta-glucuronida se in GCF was significantly decreased at 2 weeks following SRP and then dem onstrated a gradual increase throughout the study period. Levels of IgA in GCF significantly increased following SRP, reaching a peak at 6 weeks and t hen gradually decreasing throughout the study. Furthermore, we found an inv erse relationship between GCF IgA levels at 6 to 12 weeks post-SRP and the occurrence of GAL. Conclusions: These results support the hypothesis that maintenance of high levels of IgA in GCF may be "protective" against periodontal attachment los s. Furthermore, levels of beta-glucuronidase appear to be a more sensitive indicator of gingival inflammation than clinical measures.