Studies on immunological diagnosis of periodontal diseases

从微生物学、免疫学和遗传学角度研究了牙周病病原菌与宿主耐药之间的关系。采用酶联免疫吸附试验（ELISA）检测血清IgG抗体滴度，探讨其对主要牙周病细菌的诊断价值，评价临床预后。为提高酶联免疫吸附测定的效率，建立了一种新的酶联免疫吸附测定方法。采用该方法检测血清中牙龈卟啉单胞菌（p.g.）、中间普雷沃菌（p.i.）、放线菌杆菌（a.a.）和核梭杆菌的IgG抗体滴度。结果表明，改进后的方法对受试者的管理效率比原方法提高了6倍，并可用于高抗体滴度血清的筛选。牙周治疗后抗P.g.和P.i.的IgG抗体滴度明显降低。P.g.抗体活性的降低与牙周手术的频率或治疗的持续时间之间有更大的相关性。血清P.i.抗体滴度随牙数的减少而显著降低。上述结果提示，血清中P.g.和P.i.抗体滴度的降低可作为衡量牙周治疗效果的指标。我们还分析了1988 ~ 1989年两年间60例牙周病患者的抗体滴度与临床参数的关系。结果表明，血清抗P.g.抗体活性与探探深度和牙槽骨吸收率显著相关。抗aa抗体滴度也与牙槽骨吸收率相关。这些发现表明，P.g.和A.a.是导致牙周炎的关键细菌。此外，开发了用于牙周病病原体的非放射性DNA探针，如P.g.或p.i.。这些探针在临床试验中具有足够的灵敏度和特异性。DNA探针在所有检查的患者中均检测到P.g.，在探针深度深或探针出血的部位检测到P.g.的频率显著增加。这些结果提示P.g.可能在成人牙周炎中起重要作用。另一方面，利用RFLPs分析，我们检测了P.g.菌株的纤维蛋白基因位点。结果表明，纤蛋白基因座内存在遗传异质性。这也可能反映了以前报道的P.g.物种之间的毒力差异。少

The relationship between the periodontopathic bacteria and host resistance in periodontal diseases has been investigated microbiologically, immunologically and genetically. The serum IgG antibody titers were measured by using an enzyme-linked immunosorbent assay(ELISA) to investigate the diagnostic value in order to find main periodontopathic bacteria, and to evaluate the clinical prognosis. A new method of ELISA measurement was developed to improve the efficiency. Using this new method, the serum IgG antibody titers to Porphyromonas gingivalis (P.g.), Prevotella intermedia (P.i.), Actinobacillus actinomycetemcomitans (A.a.) and Fusobacterium nucleatum were evaluated. The results indicated that this improved method showed 6 times more efficient in managing subjects as compared to the former one and might be effective for screening of serum with high antibody titers. The IgG antibody titers against P.g. and P.i. decreased significantly after periodontal treatment. There is a significant … More correlation between the reduction of antibody activity to P.g. and the frequency of periodontal surgeries or the duration of treatment. The serum antibody titers to P.i. was detected to reduce significantly in relation to the number of lost teeth. These results suggest that the reduction of the serum antibody titers to P.g. and P.i. can be used as parameters to show effectiveness of periodontal treatment. We also analyzed the relation between the antibody titers and clinical parameters about 60 patients with periodontal disease measured for two years from 1988 to 1989. As results, the serum antibody activity to P.g. was significantly correlated with the probing depth and the rate of alveolar bone resorption. The antibody titers to A.a. was also correlated with the rate of alveolar bone resorption. These findings suggest that P.g. and A.a. are key bacteria to be responsible for the development of periodontitis. Futhermore, non-radioactive DNA probes for periodontopathic pathogens, such as P.g. or P.i., were developed. These probes showed sufficient sensitivity and specificity for clinical trials. By using the DNA probe, P.g. was detected from all patients examined and the frequency of P.g. detection increased significantly in the sites with deep probing depth or bleeding on probing. These results indicate that P.g. may play an important role in adult periodontitis. On the other hand, using RFLPs analysis we examined P.g. strains on their fimbrillin gene locus. The results indicate that genetic heterogeneity seems to be existing within the fimbrillin gene locus. This may also reflect the difference of virulence within P.g. species reported before. Less