弓形蟲感染症患者之臨床病理、免疫組織化學染色及血清學之研究
弓形蟲感染症患者之臨床病理、免疫組織化學染色及血清學之研究
卓麗貞a 許永祥b
摘要
本研究收集九個花蓮慈濟醫院解剖病理科證實為弓形蟲感染的案例，以HE染色觀察組織病理學變化，以免疫組織化學染色偵測弓形蟲在各組織分佈情形及探討致病機轉，茲將結果歸納如下：五例淋巴結腫大之弓形蟲淋巴結炎患者，臨床上均以淋巴結腫大為主要表現，均有典型病理變化，包括濾泡結節樣增生、副皮質有微小肉芽腫、單核細胞樣（moncytoid）B淋巴球浸潤淋巴竇，其中淋巴結可見弓形蟲包囊有二例，見弓形蟲速殖體有一例。二例愛滋病患及一例需長期使用抗排斥藥之腎臟移植患者，因免疫力低下，感染弓形蟲後，最常見的症狀是造成腦炎，其病理組織變化為腦組織壞死性病灶及血管炎，並可用免疫組織化學染色發現許多弓形蟲速殖體。一例懷孕婦女在懷孕期間感染弓形蟲後，可能傳染給胎兒造成流產，從胎盤及死胎的腦、眼睛、淋巴結、心、肝、脾、腎、肺，都發現許多弓形蟲包囊及速殖體，並以免疫組織化學染色證實。
至於檢測血清弓形蟲抗體(IgG及IgM)之表現，三例弓形蟲淋巴結炎患者IgG(+)/ IgM(+)，代表以前曾感染，這次以急性發病表現。二例 IgG(+)/ IgM(-)表示過去曾感染，其中一例組織病理切片未見包囊及速殖體，應屬慢性弓形蟲淋巴結炎;另一例切片看見許多速殖體及少許包囊，加上病原全身散佈，應是急性弓形蟲感染，IgM產生不出來，病人可能有免疫缺陷。而二例愛滋急性腦炎病患IgG(+)/ IgM(-)可能是其免疫力已大幅下降，故IgM無法產生。另一例接受過腎臟移植腦炎患者IgG(-)/ IgM(-)，推測可能因長期服用抗排斥藥，造成免疫力下降，這與有些愛滋病人免疫力缺乏嚴重受損，偵測不到抗體相似。而連續流產婦女IgG(+)/ IgM(-)，應是懷孕早期有感染弓形蟲病，病理變化為弓形蟲胎盤炎及導致死胎，流產當下檢測IgM 已是陰性。
Clinicopathology, Immunohistochemistry and Serology Study of Toxoplasmosis
（1）Five cases of lymphadenistis showed lymphadenopathy. Histopathologically, these cases demonstrate typical pathologic pictures including follicular lymphoid hyperplasia, multiple microgranulomas and monocytoid B lymphocyte infiltrating sinusoid. Among the five cases, two have cysts and one has numerous tachyzoites. All of the five cases showed toxoplama antigen distributed in cysts, tachyzoites and macrophages by immunohistochemistry staining.
（2）Three encephalitis patients include two AIDS patients and one patient received kidney transplantation over 20 years ago and was receiving long term immunosuppressant therapy. All of the three cases present encephalitis symptoms with necrotizing encephalitis. Among the three cases, two have vasculitis associated with numerous tachyzoites.
（3）One stillborn infant from a woman with frequent abortion. We observed the placenta and the infant showing necrotizing placentitis with numerous tachyzoites and variable cysts and tachyzoites in the brain, eyes, lymph nodes, heart, liver, spleen, and lung of the infant.
In addition, IgG&IgM antibodies against toxoplasmosis were also collected. IgG（+）/IgM（+） was detected in three lymphadenistis cases indicating chronic infection with acute exacerbation. The other two cases of lymphadenistis showed IgG（+）/IgM（-）. One suggested chronic infection without presence of cysts and tachyzoites identified. The other one showed systemic involvement with numerous tachyzoites infiltration that indicated acute toxoplasmosis. Perhaps due to severe immunity deficiency, IgM antibody was not detected. The two AIDS patients with encephalitis presented IgG but not IgM antibody which may be caused by significant immune deficiency that can not produce IgM. The kidney transplanted patient showed IgG（-）/IgM（-） which may be the result of a severe immunodeficiency due to long term regimen of anti-rejection medication as same as some AIDS patients with severe immunodeficiency. Lastly, the pregnant woman showed IgG（+）/ IgM（-） which may be owing to a previous infection and reactivation in early pregnancy, and IgM can not developed in terminal pregnancy.
Key words: Toxoplasmosis, Cyst, Tachyzoite, Immunohistochemistry, anti-Toxoplasma serum antibody （IgG, IgM）
