Presence of activated eosinophils, high IgE and sCD23 titers in gingival crevicular fluid of patients with adult periodontitis

Our previous studies showed that the expression of CD23 on polymorphonuclear leukocytes (PMNLs) in gingival crevicular fluid (GCF) from adult periodontitis (AP) patients was higher than in autologous peripheral blood (PB). Percentages of eosinophils in GCF PMNLs ranged between 6 and 14%. The purpose of the present studies was to increase understanding of the potential role of eosinophils and their products, including CD23, in periodontal disease. We analysed the eosinophil fraction in GCF and PB by flow cytometry using monoclonal antibodies to CD23b (BB10), eosinophil cationic protein (ECP) in stored and secretory forms (EG1 and EG2), and CD67 (80H3). Simultaneously, we measured IgE and soluble CD23 titer and GCF and serum by ELISA. Flow cytometric analysis of BB10, EG2 and 80H3 binding showed that GCF eosinophils from AP were activated. A large BB10⁺ EG2⁺ cellular fraction was detected in GCF from AP whereas it was very low in autologous serum (9.30±2.460 vs 0.16±0.10, p>0.001). GCF from gingivitis patients exhibited no flow cytometric evidence for the presence of BB10+ EG2+ cells. BB10+ EG1+ cells, or inactivated eosinophils rated lower in GCF than in PB both in gingivitis and periodontitis patients (0.45±0.63 vs 1.83±0.96 and 0.15±0.30 vs 1.30±0.20, p>0.05. respectively). IgE titer in AP patients reached 1208.1 ±421.2 IU/ml in GCF while only 49.1 ±50.4 in sera. Soluble CD23 in GCF reached 236.1 ±81.3 ng/ml in GCF and 5.6±1.8 ng/ml in sera. GCF of gingivitis patients, however, contained no detectable sCD23. Thus. GCF from AP patients displayed a high rate of activated eosinophils secreting ECP. while GCF of gingivitis patients did not. These results suggest that ECP-secreting activated eosinophils are relevant to the pathology of adult periodontitis.