Open AccessEnzyme Immunoassay Detection of Antigen-Specific Immunoglobulin G Antibodies in Longitudinal Serum Samples from Patients with Cryptosporidiosis
Author(s) -
Jeffrey W. Priest,
Anna Li,
M. Islam Khan,
Michael J. Arrowood,
Patrick J. Lammie,
Corinne S. L. Ong,
Jacquelin M. Roberts,
Judith L. Isaac-Renton
Publication year - 2001
Publication title -
clinical and diagnostic laboratory immunology
Language(s) - English
Resource type - Journals
eISSN - 1098-6588
pISSN - 1071-412X
DOI - 10.1128/cdli.8.2.415-423.2001
Subject(s) - western blot , antigen , immunoassay , antibody , cryptosporidium parvum , microbiology and biotechnology , biology , cryptosporidium , virology , blot , immunology , biochemistry , feces , gene
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.