A Study on the Relationships between the Severity of Periodontitis and Serum IgG Antibody Titer against Porphyromonas gingivalis among Patients with Hematologic Malignancies

Abstract

Infection is a critical issue in immuno-compromised patients such as with hematologic malignancies. Oral infection is no exception. Among various oral infectious diseases, periodontitis is one of the most common diseases. However, currently, very few hospitals are undertaking intensive interventions by dentists. In many other hospitals, physicians themselves must control infections, including those of oral origin. Detailed periodontal examination is almost impossible for physicians. Therefore, a simple blood test to screen for periodontal infection such as measuring antibody titer against periodontal pathogens would be a powerful tool for physicians. However, the question remains as to whether the antibody titers accurately reflect the degree of periodontitis in leukopenic patients, since both the quantity and quality of lymphocytes are greatly reduced in such patients. The aim of this study was to determine the relationship between the severity of periodontitis and serum immunoglobulin G (IgG) antibody titer against Porphyromonas gingivalis (Pg) in subjects with hematologic malignancies. A total of 122 patients receiving treatment for hematologic malignancies (M: 76, F: 46; age: 47.4±16.3y) and 150 systemically healthy subjects (M:58, F: 92; age: 43.1±18.1y) were enrolled in this study. Information on hematology of the patients was obtained from their physicians. All subjects were examined for periodontal conditions and serum IgG antibody titers against Pg FDC381 and SU63. Periodontal condition was evaluated by the Community Periodontal Index (CPI) which was scored by examining all existing teeth, and subjects were classified according to the maximum code. In each CPI, differences in the frequencies of subjects with high serum Pg IgG titer [>2 standard deviation (SD) of the mean of 20 control subjects] between the patient group and systemically healthy control group were compared. Patients with hematopoitic organ failure exhibited various white blood cell (WBC) counts. About 40% of the patients had WBC counts below 3,000 cells/μl,Severer CPI was associated with higher frequencies of the subjects with high serum Pg IgG antibody titer in both the patient groups and systemically healthy control group. In the same CPI, there were no significant differences in the frequencies of subjects with high antibody titer between the two groups. Based on these results, it is suggested that serum Pg IgG antibody titer is applicable to screen for periodontal infection in patients with hematologic malignancy even with reduced WBC counts.