Lepidi Hubert, Fournier Pierre-Edouard, Raoult Didier
Université de la Méditerranée, Marseille, France.
Emerg Infect Dis. 2006 Sep;12(9):1332-7. doi: 10.3201/eid1209.051540.
African tick-bite fever (ATBF) is a rickettsiosis caused by Rickettsia africae. We describe histologic features and immunodetection of R. africae in cutaneous inoculation eschars from 8 patients with ATBF, which was diagnosed by culture or association of positive PCR detection and positive serologic results. We used quantitative image analysis to compare the pattern of inflammation of these eschars with those from Mediterranean spotted fever. We evaluated the diagnostic value of immunohistochemical techniques by using a monoclonal antibody to R. africae. ATBF eschars were histologically characterized by inflammation of vessels composed mainly of significantly more polymorphonuclear leukocytes than are found in cases of Mediterranean spotted fever (p < 0.05). Small amounts R. africae antigens were demonstrated by immunohistochemical examination in 6 of 8 patients with ATBF. Neutrophils in ATBF are a notable component of the host reaction, perhaps because ATBF is a milder disease than the other rickettsioses. Immunohistochemical detection of rickettsial antigens may be useful in diagnosing ATBF.
非洲蜱咬热（ATBF）是由非洲立克次体引起的立克次体病。我们描述了8例经培养或PCR检测阳性与血清学结果阳性相结合确诊为ATBF患者皮肤接种焦痂中非洲立克次体的组织学特征和免疫检测情况。我们采用定量图像分析方法，将这些焦痂的炎症模式与地中海斑疹热的焦痂进行比较。我们使用针对非洲立克次体的单克隆抗体评估免疫组化技术的诊断价值。ATBF焦痂的组织学特征为血管炎症，主要由多形核白细胞组成，其数量明显多于地中海斑疹热病例（p<0.05）。8例ATBF患者中有6例通过免疫组化检查发现少量非洲立克次体抗原。ATBF中的中性粒细胞是宿主反应的一个显著组成部分，这可能是因为ATBF是一种比其他立克次体病症状较轻的疾病。立克次体抗原的免疫组化检测可能有助于ATBF的诊断。
