Priest J W, Li A, Khan M, Arrowood M J, Lammie P J, Ong C S, Roberts J M, Isaac-Renton J
Division of Parasitic Diseases, Centers for Disease Control and Prevention, Mail Stop F-13, Building 23, Room 1025, 4770 Buford Highway N.E., Atlanta, Georgia 30341-3724, USA.
Clin Diagn Lab Immunol. 2001 Mar;8(2):415-23. doi: 10.1128/CDLI.8.2.415-423.2001.
Cryptosporidium parvum is a protozoan parasite that causes diarrheal illness in a wide range of mammalian hosts, including humans. Characteristic serum immunoglobulin G (IgG) antibody responses to antigens in the 27- and 17-kDa size ranges have been shown to develop after infection, and several enzyme-linked immunosorbent assay (ELISA) and Western blot assay formats have been used to measure these IgG levels in human serum. Using a collection of serial samples from laboratory-confirmed cryptosporidiosis patients, we compared the results obtained by using two new ELISAs with those obtained with two different Western blot assays. When assayed with the large-format Western blot, 97% of the 67 patients had a demonstrable antibody response on at least one occasion. The Cp23 ELISA correctly identified 93% of the samples that had a 27-kDa response by Western blot and 100% of the negative samples. The Triton antigen ELISA detected 77% of the samples that had a 17-kDa response by Western blot and 88% of the negative samples. The sensitivity of the Triton antigen assay was higher for samples collected between 16 and 92 days after the onset of symptoms (96%). The minigel-format Western blot did not compare favorably with the large-format blot for the detection of antibodies to the 27-kDa antigen (71% sensitivity). A half-life of about 12 weeks was estimated for antibodies to both the 27- and 17-kDa antigens. We believe the Cp23 and Triton antigen ELISAs will be useful in epidemiologic studies of the prevalence of Cryptosporidium infection in the population.
微小隐孢子虫是一种原生动物寄生虫，可在包括人类在内的多种哺乳动物宿主中引起腹泻疾病。已证明感染后会产生针对27 kDa和17 kDa大小范围内抗原的特征性血清免疫球蛋白G（IgG）抗体反应，并且已使用几种酶联免疫吸附测定（ELISA）和蛋白质印迹测定方法来测量人血清中的这些IgG水平。我们使用来自实验室确诊的隐孢子虫病患者的一系列样本，比较了两种新ELISA方法与两种不同蛋白质印迹测定方法所获得的结果。当用大型蛋白质印迹法检测时，67名患者中有97%至少在一次检测中呈现出可检测到的抗体反应。Cp23 ELISA正确识别出通过蛋白质印迹法检测到有27 kDa反应的样本中的93%以及所有阴性样本。Triton抗原ELISA检测到通过蛋白质印迹法检测到有17 kDa反应的样本中的77%以及阴性样本中的88%。对于症状出现后16至92天采集的样本，Triton抗原测定的灵敏度更高（96%）。在检测针对27 kDa抗原的抗体方面，小型凝胶蛋白质印迹法与大型蛋白质印迹法相比效果不佳（灵敏度为71%）。估计针对27 kDa和17 kDa抗原的抗体半衰期约为12周。我们认为Cp23和Triton抗原ELISA将有助于人群中隐孢子虫感染流行情况的流行病学研究。
