目的：分析侵袭性牙周炎（aggressive periodontitis, AgP）患者血清中的抗伴放线聚集杆菌（Aggregatibacter actinomycetemcomitans, Aa）血清c型IgG抗体滴度及其影响因素。方法：采集62例AgP患者（18例切磨牙型，44例广泛型）和45例牙周健康者的空腹静脉血，同时收集AgP患者的龈下菌斑和非刺激性全唾液用于Aa的检测（PCR方法），应用酶联免疫吸附方法测定血清中抗Aa血清c型IgG抗体滴度。结果：AgP组和健康对照者血清中的抗Aa血清c型IgG抗体检出率均为100%，AgP组的抗体滴度为11.1±1.9，显著高于健康对照组（9.1±1.8，P<0.01）。切磨牙型AgP患者的抗Aa血清c型的IgG抗体滴度和抗体升高率与广泛型比较差异无统计学意义。唾液或龈下菌斑样本Aa检出阳性的AgP患者抗体滴度显著高于Aa阴性患者（11.9±1.3 vs. 10.7±2.1, P<0.05）。结论：Aa血清c型为我国AgP患者定植的Aa的重要血清型，广泛型AgP患者血清抗Aa抗体滴度与切磨牙型AgP患者无明显差异。

Objective：To analyze the serum IgG titers to Aggregatibacter actinomycetemcomitans(Aa) and associated factors in patients with aggressive periodontitis (AgP).Methods:Venous blood samples were collected from 62 AgP patients and 45 periodontal healthy controls, unstimulated whole saliva and pooled subgingival plaque samples of AgP patients were also collected for the detection of Aa (PCR method). Serum IgG titers to Aa serotype c were measured by enzyme-linked immunosorbnent assay (ELISA).Results:The detection rates of serum IgG to Aa serotype c in the AgP patients and the healthy controls were both 100%. The AgP patients exhibited significantly higher IgG titers to Aa serotype c than the healthy controls (11.1±1.9 vs. 9.1±1.8, P<0.01). There was no significant difference in serum IgG levels to Aa serotype c and in the prevalence of high-responding patients to Aa serotype c between the incisor-first molar type AgP patients and generalized AgP patients. Serum IgG titers to Aa serotype c in the Aa-positive AgP patients (the patients who were Aa-positive in subgingival plaque or saliva) were significantly higher than those of the Aa-negative patients (11.9±1.3 vs. 10.7±2.1, P<0.05). Conclusion:Serotype c was the main serotype of Aa in Chinese patients with AgP. Serum IgG responses in generalized AgP patients were comparable to those in incisor-first molar type AgP patients.