皮肤结核的实验室检查

Laboratory examination of cutaneous tuberculosis

皮肤结核的临床表现缺乏特异性，传统的检查方法操作复杂、耗时长、敏感性和特异性差，容易造成漏疹和误诊。近年来，皮肤结核实验室检查有了新的进展，其中以PCR为基础的核酸扩增技术及环介导等温扩增法，能够快速、特异、敏感地进行分子诊断。酶联免疫斑点技术可代替纯化蛋白衍生物试验，为早期诊断结核潜伏感染提供新的方向：针吸细胞学检查结合抗酸染色或免疫组化能早期诊断并减少活检带来的创伤。BACTEC技术可以对分枝杆菌进行快速自动化分析和药敏试验。这些新的检测技术极大地提高皮肤结核的诊断水平。

The clinical manifestation of cutaneous tuberculosis is nonspeeific. Conventional diagnosis based on smear microscopy, culture and histopathology usually requires complicated procedures and is time-consuming with limited sensitivity and specificity. This review describes recent advances and emerging technologies in the diagnosis of cutaneous tuberculosis as well as in the detection of drug resistance. Nucleic acid amplification tests, such as PCR or loop-mediated isothermal amplification of DNA could make molecular diagnosis rapidly, sensitively and specifically, and appear to be a promising tool in the diagnosis of cutaneous tuberculosis. Enzyme-linked immunospot, based on the detection of interferon released by T cells in response to M.tuberculosis-specitic antigens, may take the place of purified protein derivative of tuberculin （PPD） test. Fine-needle aspiration cytology with acid fast bacilli or immunohistochemistry staining may carry out an early diagnosis without physical or psychological trauma resulted from biopsy. BACTEC system, a more sensitive and less time-consuming culture technique, has been applied to rapid automatic analysis and drug susceptibility test. These novel techniques will dramatically improve the diagnosis of cutaneous tuberculosis.