Mbassa G K, Kipanyula M J, Mellau L S B, Mwamakali E D, Bulegeya F R, Kauto-Mboni K
Department of Veterinary Anatomy, Faculty of Veterinary Medicine, Sokoine University of Agriculture, P.O. Box 3016, Morogoro, Tanzania.
Vet Parasitol. 2006 Dec 20;142(3-4):260-70. doi: 10.1016/j.vetpar.2006.07.010. Epub 2006 Sep 7.
In a study of trends and magnitudes of lymphocytes proliferation, destruction or apoptosis eleven 3-month-old healthy calves were experimentally infected with the protozoan parasite Theileria parva, which is reported to cause lymphocyte proliferation. Four control calves were not infected. Infected and non-infected calves were sacrificed on days 9, 12, 16, 19, 23, 24 and 25 to examine lymphoid tissue changes and lymphocyte proliferation, apoptosis or necrosis in the thymus, spleen and lymph nodes. All infected calves developed severe East Coast fever, with enlargement of lymph nodes, dyspnoea, high fever and pulmonary oedema. Lymphocyte proliferation was not observed in lymph nodes, thymus and spleen; instead there were massive deaths of lymphocytes and other cells. The terminal severe disease caused massive lymphoid parenchyma coagulation terminating with caseation, organs and cells being undeterminable histologically. Tissues surrounding the lymph nodes were oedematous. Lymph node and thymus parenchyma were caseated and cortices and medulla indistinguishable because of severe lymphocyte and accessory cell deaths. The lymph node fibrous reticular stroma was necrotic and caseated. Lymphoid follicles in lymph nodes degenerated and lacked germinal centres. Lymph nodes, spleen and thymus were grossly enlarged, hardened, potato or cheese like, but microscopically very hypocellular and in the terminal disease acellular because of massive lymphocytes destruction. In the thymus there was extensive thymocyte and epithelioid cell necrosis and loss of distinction between cortex and medulla. The spleen white and red pulps were indistinguishable because of extensive lymphoid cell necrosis. The white pulp degenerated more than the red pulp. The massive lymphocyte deaths in the lymph nodes, thymus and spleen, without lymphocyte proliferation in this T. parva infection in calves leads to a conclusion that this parasite is lympho-destructive and lympho-degenerative in vivo rather than lympho-proliferative.
在一项关于淋巴细胞增殖、破坏或凋亡的趋势及程度的研究中，11头3月龄健康犊牛被实验性感染原生动物寄生虫小泰勒虫，据报道该寄生虫会引起淋巴细胞增殖。4头对照犊牛未被感染。在第9、12、16、19、23、24和25天对感染和未感染的犊牛实施安乐死，以检查胸腺、脾脏和淋巴结的淋巴组织变化以及淋巴细胞增殖、凋亡或坏死情况。所有感染的犊牛均患上严重的东海岸热，出现淋巴结肿大、呼吸困难、高热和肺水肿。在淋巴结、胸腺和脾脏中未观察到淋巴细胞增殖；相反，出现了大量淋巴细胞和其他细胞的死亡。终末期的严重疾病导致大量淋巴实质凝固，最终形成干酪样坏死，从组织学上无法确定器官和细胞。淋巴结周围组织水肿。淋巴结和胸腺实质干酪样坏死，由于严重的淋巴细胞和辅助细胞死亡，皮质和髓质无法区分。淋巴结纤维网状基质坏死并干酪样化。淋巴结中的淋巴滤泡退化，缺乏生发中心。淋巴结、脾脏和胸腺明显肿大、变硬，呈土豆样或奶酪样，但在显微镜下细胞非常少，在终末期疾病中由于大量淋巴细胞破坏而无细胞。在胸腺中，胸腺细胞和上皮样细胞广泛坏死，皮质和髓质之间的区别消失。由于广泛的淋巴细胞坏死，脾脏的白髓和红髓无法区分。白髓比红髓退化更严重。在犊牛的这种小泰勒虫感染中，淋巴结、胸腺和脾脏中大量淋巴细胞死亡，而无淋巴细胞增殖，由此得出结论，这种寄生虫在体内具有淋巴细胞破坏性和淋巴细胞变性性，而非淋巴细胞增殖性。
