Aita Tetsuro, Sando Eiichiro, Katoh Shungo, Hamaguchi Sugihiro, Fujita Hiromi, Kurita Noriaki
Department of General Internal Medicine, Fukushima Medical University, Fukushima, Japan; Department of Clinical Epidemiology, Graduate School of Medicine, Fukushima Medical University, Fukushima, Japan.
Department of General Internal Medicine and Clinical Infectious Diseases, Fukushima Medical University, Fukushima, Japan; Department of General Internal Medicine and Infectious Diseases, Kita-Fukushima Medical Center, Fukushima, Japan; Institute of Rickettsioses, Kita-Fukushima Medical Center, Fukushima, Japan.
Int J Infect Dis. 2023 May;130:178-181. doi: 10.1016/j.ijid.2023.03.012. Epub 2023 Mar 11.
We examined the frequency of cross-reactions to Rickettsia typhi in patients with Japanese spotted fever (JSF) and evaluated the differences between two rickettsiae using antibody endpoint titers.
Patients' immunoglobulin (Ig)M and IgG titers against Rickettsia japonica and Rickettsia typhi in two phases were measured using an indirect immunoperoxidase assay at two reference centers for rickettsiosis in Japan. Cross-reaction was defined as a higher titer against R. typhi in convalescent sera than in acute sera among patients fulfilling the criteria for JSF diagnosis. The frequencies of IgM and IgG were also evaluated.
Approximately 20% of cases showed positive cross-reactions. A comparison of antibody titers revealed the difficulty in identifying some positive cases.
Cross-reactions of 20% in serodiagnosis may lead to the misclassification of rickettsial diseases. However, with the exception of some cases, we were able to successfully differentiate JSF from murine typhus using each endpoint titer.
我们研究了日本斑点热（JSF）患者中对伤寒立克次体交叉反应的频率，并使用抗体终点滴度评估了两种立克次体之间的差异。
在日本两个立克次体病参考中心，采用间接免疫过氧化物酶测定法，测量了患者在两个阶段针对日本立克次体和伤寒立克次体的免疫球蛋白（Ig）M和IgG滴度。交叉反应定义为在符合JSF诊断标准的患者中，恢复期血清中针对伤寒立克次体的滴度高于急性期血清。还评估了IgM和IgG的频率。
约20%的病例显示出阳性交叉反应。抗体滴度的比较显示难以识别一些阳性病例。
血清学诊断中20%的交叉反应可能导致立克次体病的错误分类。然而，除了一些病例外，我们能够使用每个终点滴度成功地将JSF与鼠型斑疹伤寒区分开来。
