Enzyme immunoassay detection of antigen-specific immunoglobulin g antibodies in longitudinal serum samples from patients with cryptosporidiosis.
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.
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. jpriest@cdc.gov
J W
JW
Priest
A
A
Li
M
M
Khan
M J
MJ
Arrowood
P J
PJ
Lammie
C S
CS
Ong
J M
JM
Roberts
J
J
Isaac-Renton
D000328:Adult; D000818:Animals; D000953:Antigens, Protozoan / Q000032:analysis* / Q000276:immunology; D015153:Blotting, Western; D003457:Cryptosporidiosis / Q000175:diagnosis* / Q000453:epidemiology; D016785:Cryptosporidium parvum / Q000276:immunology* / Q000302:isolation & purification; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D008137:Longitudinal Studies; D012680:Sensitivity and Specificity; D016036:Seroepidemiologic Studies
D000953:Antigens, Protozoan; D007074:Immunoglobulin G