Molaie Soheila, Mohebali Mehdi, Abai Mohamad-Reza, Molaie Akbar, Akhoundi Behnaz, Asl Eslam Moradi
Kala-Azar Laboratory, Health Center, Ardabil University of Medical Scince, P.O. Box 56617-45378, Meshkinshahr, Iran.
Department of Medical Parasitology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.
J Parasit Dis. 2017 Jun;41(2):446-449. doi: 10.1007/s12639-016-0825-y. Epub 2016 Aug 31.
The early diagnosis of visceral leishmaniasis (VL) using Direct Agglutination Tests (DAT) and its treatment and control are essential actions taken in rural health centers in endemic foci of the infection based on the national protocols set by the Iranian Ministry of Health and Medical Education. Eleven clinically confirmed VL patients with typical VL symptoms and negative results of DAT, admitted to the pediatrics department of Valiasr Hospital in Meshkinshahr underwent parasitological tests. 7 of the total of 11 patients had positive result of bone marrow puncture smears and all of them had negative results of DAT. Thus factors that had led to false negative DAT results were examined. The patients' blood samples were collected in microhematocrit tubes using the finger prick technique, centrifuged and their plasma then separated. The complete medical history of the patients was taken using a questionnaire. The laboratory staff therefore checked the quality of anti-leishmania antigen, materials and equipment used. The patients' medical history showed that they had all been administered corticosteroid medications such as dexamethasone or hydrocortisone prior to visiting the laboratory. The DAT was repeated in these patients 2-3 weeks after their last administration of corticosteroids. The antibody titers were positive this time. A total of 3 of the collected specimens (27.3 %) showed a titer of 1.3200, 5 (46 %) showed a titer of 1.1600 and 3 (27.3 %) a titer of 1.800. Due to the effects of some medications, particularly corticosteroids, on serological tests, the patients' full medical history should be taken prior to performing this test and physicians working at endemic regions of this infection should be notified about these drug interactions.
根据伊朗卫生和医学教育部制定的国家方案，在内脏利什曼病（VL）流行地区的农村卫生中心，采用直接凝集试验（DAT）进行早期诊断、治疗和控制是至关重要的措施。11例临床确诊为典型VL症状且DAT结果为阴性的患者入住梅什金沙尔市瓦利亚斯尔医院儿科，接受了寄生虫学检查。11例患者中，7例骨髓穿刺涂片结果为阳性，而DAT结果均为阴性。因此，对导致DAT结果假阴性的因素进行了检查。采用手指针刺技术，将患者的血液样本收集到微量血细胞比容管中，离心后分离出血浆。通过问卷调查获取患者的完整病史。实验室工作人员检查了抗利什曼原虫抗原、所用材料和设备的质量。患者的病史显示，他们在到实验室就诊之前均服用过皮质类固醇药物，如地塞米松或氢化可的松。在这些患者最后一次服用皮质类固醇药物2至3周后，再次进行DAT检测。此次抗体滴度呈阳性。共收集到3份标本（27.3%）的滴度为1:3200，5份（46%）的滴度为1:1600，3份（27.3%）的滴度为1:800。由于某些药物，特别是皮质类固醇药物对血清学检测有影响，在进行此项检测之前应了解患者的完整病史，并且应告知在该感染流行地区工作的医生这些药物相互作用的情况。
