Digoxinbestimmung mit Enzymimmunoassay und Radioimmunoassay

Zusammenfassung Digoxin-Konzentrationen in Patientenseren wurden parallel mittels Enzymimmunoassay (EMIT-EIA) und Radioimmunoassay (RIA,¹²⁵J markiert) bestimmt und die Ergebnisse miteinander verglichen. Im unselektierten Patientenmaterial (n=104) bestanden teilweise erhebliche Bestimmungsunterschiede; die mit dem EIA gemessenen Konzentrationen waren signifikant kleiner (1,09±0,99 ng/ml für EIA, 1,34±1,01 ng/ml für RIA,p<0,01). Hämolytische, lipämische und urämische Seren hatten falsch negative Ergebnisse im EIA; nach Elimination dieser Seren resultierte eine gute Übereinstimmung der Meßwerte mit beiden Methoden (1,12±1,01 ng/ml für EIA, 1,12±1,02 ng/ml für RIA,r=0,95,n=63).     

Comparative evaluation of the Premier™ enzyme immunoassay,micro-immunodiffusion and complement fixation tests for the detection of Histoplasma capsulatum var. capsulatum antibodies

A total of 178 sera, including 68 from proven cases of histoplasmosis (65 positive for the presence of Histoplasma capsulatum var. capsulatum antibodies and three positive for antigen), 93 from patients with suspected histoplasmosis but with no laboratory evidence of H. capsulatum var. capsulatum infection, 14 from humans with heterologous fungal and non-fungal infections and three from normal individuals, were tested for IgG H. capsulatum antibodies and M or M and H precipitins by enzyme immunoassay (EIA) (Meridian Diagnostics, Cincinnati, OH, USA) and microimmunodiffusion (MID) respectively. Sixty-three of the 68 histoplasmosis case sera demonstrated IgG antibody, and 65 of 68 demonstrated the presence of specific precipitins in the MID test. Nine positive case sera, when tested with the Laboratory Branch complement fixation (LBCF) test, reacted positively to whole yeast and histoplasmin antigens (titres 1 : 8 to 1 : 512). Three histoplasmosis case sera repeatedly tested negative for IgG, specific precipitins and complement-fixing antibodies, whereas they were positive for Histoplasma antigen. Eighteen of 95 sera from patients without evidence of histoplasmosis demonstrated IgG antibody in the EIA only. Among these positive sera, three out of three cases of aspergillosis and three out of five cases of blastomycosis were confirmed. Sera from HIV-infected and healthy individuals did not show IgG or M and/or H antibodies to H. capsulatum. Ninety-three sera were negative by both EIA and MID. The EIA for IgG was less sensitive (97%) than MID (100%). The specificity of EIA and MID was 84% and 100% respectively.     

Zum enzymatisch-immunochemischen Nachweis des Haschischkonsums und seiner dünnschichtchromatographischen Absicherung

Zusammenfassung Mit Hilfe des Enzymimmunoassay (EMIT-dau-Syva) lassen sich Cannabinoide in Blut und Urin nach inhalativer (10 mg THC) oder oraler (30 mg THC) Aufnahme nachweisen. Die Kurvenverläufe werden mitgeteilt. Im Urin waren erhöhte Spiegel bis zu einer Woche nachweisbar. Eine Absicherung der EMIT-Befunde ist mittels Dünnschichtchromatographie nach absorptiver Anreicherung an einer C₁₈-Extraktionssäule möglich. Nachweisgrenze ist 10 ng THC-Carbonsäure/ml bei Einsatz von 10 ml Urin.     

Comparison of enzyme immunoassay and immunodiffusion for the detection of canine blastomycosis

Two Blastomyces dermatitidis commercial immunodiffusion antigens, Meridian Diagnostics and Nolan-Scott Laboratories, and two B. dermatitidis yeast phase lysate antigens, T-58 and K-Le, prepared in our laboratory were utilized in an enzyme-linked immunosorbent assay (ELISA) for the detection of antibodies in 61 serum specimens from dogs with blastomycosis. All antigens used in the ELISA were diluted to 50 ng of protein ml-1. Immunodiffusion (ID) tests were also performed on the sera using a Nolan-Scott ID antigen. Greater reactivity, based on the ELISA index value, was evidenced with the two yeast phase lysate antigens over the two commercial reagents in the ELISA. In addition the sensitivity of the ELISA with the T-58, K-Le and Meridian antigens was considerably greater than that of the ID test. The Nolan-Scott antigen, however, was able to detect more positive specimens when used in the ID procedure than in the ELISA. Therefore encouraging results were obtained with respect to the continued development and optimization of the ELISA using B. dermatitidis cell lysate antigens for the diagnosis of blastomycosis.     

Enzyme immunoassay detection of antibodies in canine blastomycosis using Blastomyces dermatitidis lysate antigens

A Blastomyces dermatitidis yeast phase lysate antigen (T-58) prepared in our laboratory was used in an enzyme-linked immunosorbent assay (ELISA) for the detection of antibodies in 201 serum specimens from dogs with blastomycosis. In addition 36 sera from non-infected dogs from an endemic area for blastomycosis and 36 sera from non-infected dogs residing in a blastomycosis non-endemic area were assayed. Sensitivity values ranged from 96.2% (53 pre-treatment sera) to 88.5% (148 post-treatment sera) with the specimens from dogs with confirmed blastomycosis. Minimal reactivity was experienced with the sera from non-infected dogs. Positive reactions were obtained with 8.3% of the endemic area sera and with 5.6% of the sera from the non-endemic area. Mean ELISA index values ranged from 7.66 with the pretreatment sera to 1.11 and 1.03 with the endemic area sera and non-endemic area specimens respectively.     

Antigen detection in invasive aspergillosis and candidosis: the Austrian experience

In order to assess the performance of different methods for the detection of fungal antigens, data of five Austrian hospitals were evaluated. The enzyme immunoassay (EIA) Platelia Aspergillus Antigen (Bio-Rad, USA) was used for the diagnosis of invasive aspergillosis and compared with clinical data. It could be shown that it is more effective to investigate at least two sequential sera than only one sole serum. For several high-risk patients diagnosis could be improved or confirmed by investigating other body fluids such as cerebrospinal fluid or bronchoalveolar lavage fluid in addition to sera. For invasive Candida infections several diagnostic kits detecting antigens are commercially available. The performance of the EIA Platelia Candida Antigen (Bio-Rad, USA), the latexagglutination test Cand-Tec (Ramco, USA) and the detection of (1-3)-Beta-D-Glucan using the test kit Glucatell (CAPE COD, USA) were evaluated. The detection of (1-3)-Beta-D-Glucan by means of Glucatell showed the highest sensitivity as all sera of 15 patients with invasive candidosis showed positive results. The other tests showed positive and negative results independently of the occurrence of an invasive infection. However, the number of tested sera is too small to decide which test is the most appropriate for establishing an early and definite diagnosis. Prospective studies in combination with clinical data are still needed for definite evaluation.