Immunoglobulin isotypes in gingival crevicular fluid: possible protective role of IgA

In order to simultaneously assess the local humoral immune and polymorphonuclear leukocyte (PMN) responses in periodontal disease, IgG, IgM, and IgA, as well as the PMN lysosomal enzyme beta-glucuronidase (beta G), were examined in gingival crevicular fluid (GCF) from patients with varying degrees of periodontal pathology. Evaluations were made before and after conservative therapy (scaling and root planing). Thirty patients with varying degrees of periodontal pathology, ranging from mild inflammatory gingivitis to moderate periodontitis, were studied. GCF was collected from the mesial surfaces of all teeth. The presence of the 3 immunoglobulin isotypes was determined by enzyme linked immunosorbent assays (ELISA), while total beta G activity in GCF was determined by a fluorometric assay. Clinical parameters were obtained from 6 sites per tooth. Our data indicate that prior to treatment, total beta G activity is strongly related to the severity of periodontal disease as measured by mean probing attachment level (AL; r = 0.89; P < .005), mean probing depth (PD; 4 = 0.89; P < .0005) and percentage of sites exhibiting bleeding on probing (% BOP; r = 0.49; P < .005). Following treatment, no statistically significant relationship of disease severity and beta G is found. The concentrations of IgG and IgM in GCF do not follow a specific pattern when related to disease severity. In contrast, prior to treatment the concentration of IgA is negatively correlated to mean AL (r = -0.54; P < .005), mean PD (r = -0.59; P < .005), and % BOP (r = -0.47, P < .005).(ABSTRACT TRUNCATED AT 250 WORDS)