Study On The Differential Diagnosis Of Paragonimus,Taenia Solium Cysticercus And Sparganum In Pathological Section

Objective:The identification of various helminthes in pathological section is a common problem in the clinical pathologic diagnosis, because the morphological features of different species still have not had the systematic description and the reliable picture for reference so far, and none of practical method to identify the helminthes species of the clinical sample. This paper studied on morphological comparative analysis and gene diagnosis aiming at the pathological sections of three helminthes (Paragonimus, Taenia Solium cysticercus and Sparganum mansoni).Methods:Many different kinds of helminthes paraffin section specimens from animal or clinical patients were collected, and twelve clinical pathological section samples from the clinical suspected patients with being infected three helminthes were obtained. The similarity and characteristic of organizational structure were observed and analyzed by the optical microscope for three helminthes, and also described the atypical morphological characteristic of clinical sections sample which were the degenerated polypide tissues. According to the specific gene sequence of three helminthes, The corresponding PCR primers were designed to analyse the specificity of three helminthes, and also explore a experimental method which can extract DNA from untreated section, stained section and immunohistochemistried section, and also acquired the different tissue quantity of three helminthes to meet the requirements of the PCR amplified gene. Finally, we checked whether the method is practical in clinical specimens.Results:Three helminthes and other trematodes are similar morphology on the reticular structure and the cortex; Three helminthes possess respectively their characteristic marks. Paragonimus have many sharp spines on the cortex, elliptical cross section, its parenchyma with the tubal organs and the suckers. Taenia Solium cysticercus has the larger section and many irregular cavities; The cross section of Sparganum is oblong and contain a lot of calcareous corpuscles; The degeneration and denaturation of helminthe makes those characteristic structures vanish. According to Paragonimus primers (L12/R12and F3/B3), Sparganum primers (F650/R800) and Taenia Solium Cysticercus primers (F3/R7), Genetic test results show that three corresponding helminthes have obvious target bands by PCR but others without any bands. The modified proteinase K digestion method, which can extract DNA to meet the requirements of PCR, require respectively the minimum area and thickness of tissue:Paragonimus is1.50mm2×10μm, Sparganum mansoni is4.87mm2×5μm, and Taenia Solium Cysticercosis is5.80mm2×5μm.Conclusion:The histopathology of three helminthes have been described for the first time, which provides the basis for the pathological and morphological identification. This gene diagnosis method is rapid, simple, specific, sensitive and suitable for clinical diagnosis and differentiation of three helminthes.