Reproducible enzyme-linked immunosorbent assay with a magnetic processing system for diagnosis of toxoplasmosis

Konishi, Eiji; Takahashi, Junko

doi:10.1128/jcm.17.2.225-231.1983

Cited by 16 publications

(5 citation statements)

References 16 publications

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“…Antibodies to Toxoplasma were measured by conventional ELISA essentially as previously described (Konishi & Takahashi, 1983). The dilution of test sera was 1:100.…”

Section: Elisamentioning

confidence: 99%

Naturally occurring immunoglobulin Mantibodies toToxoplasma gondiiin Japanese populations

Konishi

1991

Parasitology

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Varying degrees of naturally occurring immunoglobulin (Ig) M antibodies to Toxoplasma gondii were observed in almost all of adult Japanese populations negative for IgG antibodies as determined by an enzyme-linked immunosorbent assay (ELISA). The antibody activity was reduced by absorption of sera with Toxoplasma soluble antigen or by 2-mercaptoethanol treatment of the IgM fraction after sucrose density gradient centrifugation. Umbilical cord sera had almost no detectable IgM antibodies, and the ELISA value in infants increased with age until 1 year. Most paired sera collected from adults at a 1-year interval showed constant IgM antibody levels, suggesting retention of natural IgM antibodies throughout their lives without changing ELISA values of greater than or equal to 0.1/year. Polar staining was observed in immunofluorescent studies for 14 serum samples with natural IgM antibody levels of greater than or equal to 0.5, while samples obtained from a pregnant woman with natural IgM antibody levels of greater than or equal to 0.9 reacted to the whole organism as was observed in positive sera of acute patients. Western blotting analysis revealed that natural IgM antibodies were directed to multiple antigen molecules. The band pattern differed slightly from one serum to another, but almost consistent patterns were observed in sera sequentially obtained from an adult over 4 years.

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“…Antibodies to Toxoplasma were measured by conventional ELISA essentially as previously described (Konishi & Takahashi, 1983). The dilution of test sera was 1:100.…”

Section: Elisamentioning

confidence: 99%

Naturally occurring immunoglobulin Mantibodies toToxoplasma gondiiin Japanese populations

Konishi

1991

Parasitology

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“…The ELISA test was performed with polycarbonate-coated iron beads as the solid phase and with a magnetic transfer system as previously described [Konishi and Yamaoka, 1982;Yamaoka et al, 19821. The beads were simultaneously transferred from one reagent to another through a wash bath [Konishi and Takahashi, 1983;Yamaoka et al, 19831. Briefly, ELISA was performed by reacting the sensitized beads with swine serum, alkaline phosphatase-conjugated rabbit anti-porcine IgG or IgM, and p-nitrophenyl phosphate.…”

Section: Elisa Proceduresmentioning

confidence: 99%

Recent changes in prevalence pattern of Japanese encephalitis virus in hyogo prefecture, Japan, using a two‐dimensional distribution of IgG and IgM class antibody levels in swine sera

Yamaoka

Konishi

1985

Journal of Medical Virology

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Surveillance of antibody to Japanese encephalitis (JE) virus in swine sera was performed during the epidemic season from July to September, 1978 to 1983, in Hyogo Prefecture, Japan, using enzyme-linked immunosorbent assay (ELISA). Two-dimensional distribution analyses of ELISA values for IgG and IgM class antibodies indicated recent changes in the prevalence pattern. Time courses of antibody levels observed from 1978 to 1980 were similar to those in the 1960s of major epidemics, indicating a synchronous infection during the second wave of infection. In 1982 and 1983, however, the JE prevalence pattern implies an incessant infection cycle between vector mosquitoes and pigs during the latter half of the epidemic season. The delay of the occurrence of JE in patients confirms the longer period of exposure to infectious vectors.

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“…Three of the earliest and best-characterized serological tests for the diagnosis of toxoplasmosis have been the Sabin-Feldman dye test (11), the indirect hemagglutination assay (6), and the indirect immunofluorescence test (14). Various enzyme immunoassays (EIAs) have also been evaluated for their ability to detect anti-T. gondii antibodies in serum (8,9,12,13,17,18).…”

mentioning

confidence: 99%

Comparison of the Vitek Immunodiagnostic Assay System with an indirect immunoassay (Toxostat Test Kit) for detection of immunoglobulin G antibodies to Toxoplasma gondii in clinical specimens

et al. 1991

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The value and convenience of testing for specific anti-Toxoplasma gondii antibodies have led to the development of various antibody detection methods, such as the enzyme immunoassay. Two enzyme immunoassays, the Vitek Immuno-Diagnostic Assay System (VIDAS; Vitek Systems, Hazelwood, Mo.) and the Toxostat Test Kit (TST; Whittaker Bioproducts, Walkersville, Md.), were compared for their ability to detect T. gondii immunoglobulin G antibodies in fresh human sera. Specimens were tested according to the instructions of each manufacturer. Of 304 serum specimens tested, the results for 282 (93%) agreed in both assays (77 were positive and 205 were negative). The results for the remaining 22 (7%) specimens were discrepant; 20 of the 22 specimens tested low positive or equivocal by Toxostat and negative by VIDAS. Upon retesting, 8 of these 22 specimens were in concordance, increasing the level of agreement to 95.3%. Intra-assay reproducibility was tested with four to nine replicates of each of seven samples (four positive, one negative, and two equivocal) by both tests and six replicates of one standard by VIDAS. Coefficients of variation (CVs) for VIDAS were 6, 8, 10, 15, 18, 19, and 23% for the samples and 14% for the standard. For Toxostat the CVs were 2, 8, 10, 10, 13, and 16%. In general, CVs for VIDAS were slightly larger than the CVs for Toxostat. Day-today variability over 3 days was tested by VIDAS for only six samples (three positive, two negative, and one equivocal) and four standards; CVs ranged from 2 to 15% for the samples and from 6 to 13% for the standards. In conclusion, VIDAS is a rapid, convenient, non-labor-intensive, and easily performed test for the detection of immunoglobulin G antibodies to T. gondii in serum specimens.

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Reproducible enzyme-linked immunosorbent assay with a magnetic processing system for diagnosis of toxoplasmosis

Cited by 16 publications

References 16 publications

Naturally occurring immunoglobulin Mantibodies toToxoplasma gondiiin Japanese populations

Naturally occurring immunoglobulin Mantibodies toToxoplasma gondiiin Japanese populations

Recent changes in prevalence pattern of Japanese encephalitis virus in hyogo prefecture, Japan, using a two‐dimensional distribution of IgG and IgM class antibody levels in swine sera

Comparison of the Vitek Immunodiagnostic Assay System with an indirect immunoassay (Toxostat Test Kit) for detection of immunoglobulin G antibodies to Toxoplasma gondii in clinical specimens

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