Techniques of aspiration cytology, biopsy and cell block of the bone marrow for the identification and determination of parasite intensity in Canine Visceral Leishmaniasis

ABSTRACT The aim of the present study was to compare the aspiration cytology, biopsy and cell block techniques for identification and parasitological quantification of Leishmania (Leishmania) infantum chagasi in dog bone marrow. Bone marrow tissue samples from 26 animals, in different clinical-laboratory stages of the disease, were studied according to the same criteria of investigation in the aspiration cytology, biopsy and cell block techniques. The lowest number of fields for the parasitological confirmation was found in the direct smear obtained by aspiration cytology. The clinical-laboratory stage did not influence the number of fields required for the first visualization of the agent in any of the techniques (p> 0.05) and less parasitic intensity was observed in the cell block slides. The aspiration cytology and biopsy techniques agreed on the estimation of infectivity coefficient in the tissue studied (p< 0.05). Although the cell block technique allows the concentration of cells and better reutilization of samples, it has not been shown to be an adequate method for rapid identification and parasitological quantification in canine visceral leishmaniasis. Considering its advantages, aspiration cytology was the best method for microscopic detection of the parasite and determination of the level of parasite intensity in the tissue studied.

摘要
本研究旨在对比穿刺细胞学（aspiration cytology）、活检（biopsy）与细胞块（cell block）三种技术，用于犬骨髓内利什曼原虫（Leishmania (Leishmania) infantum chagasi）的鉴定及寄生虫学定量分析。本研究纳入26例处于不同临床-实验室疾病分期的动物骨髓组织样本，按照统一检测标准，分别采用此三种技术完成检测。结果显示，穿刺细胞学直接涂片的寄生虫学确认所需镜检视野数最少。无论采用何种检测技术，临床-实验室分期均未对首次检出病原体所需的视野数产生影响（p>0.05）；且细胞块切片中的寄生虫载量更低。穿刺细胞学与活检技术在评估所研究组织的感染系数时结果一致（p<0.05）。尽管细胞块技术可实现细胞浓缩并提升样本复用效率，但在犬内脏利什曼病（canine visceral leishmaniasis）的快速鉴定与寄生虫学定量分析中，该技术并非适宜的检测方法。综合其技术优势，穿刺细胞学是在所研究组织中实现寄生虫显微镜检测及寄生虫载量定量的最优检测方法。