目的：分析17例单中心临床诊断的X连锁无丙种球蛋白血症（X-linked agammaglobulinemia, XLA）的临床表型特点。方法：2000年1月至2007年4月北京儿童医院住院患儿，根据临床反复感染表现、血IgG<2g/L、外周血成熟B淋巴细胞缺失或明显降低（<1%）诊断为XLA者，分析临床特点，总结规律。结果：首次诊断年龄平均为7.7岁，88.2%患儿首次诊断年龄>6岁。首次出现症状年龄平均为4.2岁，11.8%患儿首次出现症状年龄<1岁，17.6%患儿首次出现症状年龄为1~2岁。64.7%患儿首发症状为呼吸系统感染，大部分患儿均以此为主诉入院。35.3%患儿有关节炎表现。皮肤及软组织感染少见于<1岁年龄组。大年龄组患儿可出现突发败血症和/或深位部感染。结论：该组患儿发病年龄及首次诊断年龄均较迟，呼吸系统感染为最常见的主诉，关节炎的比例较高。>1/2的患儿血CD4+T细胞减少，CD8+T细胞增加，CD4/CD8比例倒置，NK细胞减少。

OBJECTIVE: To investigate clinical features of X-linked agammaglobulinemia (XLA) in children. METHODS: The medical records of 17 children with XLA between January 2001 and April 2007 were reviewed. RESULTS: The age at first diagnosis in 88.2% of patients was more than 6 years, with a mean of 7.7 years. Twelve patients(70.6%) presented first symptoms over 2 years old, with a mean of 4.2 years. Respiratory infections as first symptoms and complaints occurred in 64.7% of the patients and 35.3% of the patients presented with polyarthritis. Skin and soft tissue infections were rarely seen in less than 1 year old group children. Abrupt sepsis and abscess in deep tissues were seen in the older children. CD4+ T cells decreased and CD8+ T cells increased in 9 patients and an inversed ratio of CD4+/ CD8+ was observed in 11 patients. CONCLUSIONS: Both the age presenting first symptoms and the age at first diagnosis in children with XLA in this study were later than the reported data. Respiratory infection was the most common manifestation. High prevalence of polyarthritis was observed. Abnormal T cell phenotypes occurred in more than one half of patients.