Comparison of enzyme-linked immunosorbent assay with coagglutination and latex agglutination for rapid diagnosis of pneumococcal pneumonia by detecting antigen in sputa.
A sandwich enzyme-linked immunosorbent assay detecting the species-specific pneumococcal C polysaccharide was compared to latex agglutination and a coagglutination test which detected capsular pneumococcal antigens in sputum specimens with regard to specificity and sensitivity. Specimens from 52 patients with clinical and radiological evidence for pneumonia were tested. Twenty-one patients with Streptococcus pneumoniae isolated in sputum and 31 patients with a non-pneumococcal etiology were included. The predictive values for a positive test by enzyme-linked immunosorbent assay was 0.91 and for a negative test 0.97, by latex agglutination 0.90 and 0.91, and by coagglutination 0.84 and 0.85 respectively; these values did not show a statistically significant difference. Whereas agglutination tests are technically more simple and can be performed more rapidly, the enzyme-linked immunosorbent assay has the advantage of detecting pneumococcal C polysaccharide, an antigen common to all pneumococci. Thus it provides an interesting alternative to tests based on serum containing antibodies to all 83 different capsular polysaccharides.
D000293:Adolescent; D000328:Adult; D000368:Aged; D000372:Agglutination Tests; D000942:Antigens, Bacterial / Q000032:analysis*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007841:Latex Fixation Tests; D008297:Male; D008875:Middle Aged; D011018:Pneumonia, Pneumococcal / Q000175:diagnosis*; D011135:Polysaccharides, Bacterial / Q000032:analysis*; D013183:Sputum / Q000276:immunology / Q000382:microbiology*; D013296:Streptococcus pneumoniae / Q000276:immunology / Q000302:isolation & purification*
D000942:Antigens, Bacterial; D011135:Polysaccharides, Bacterial; C027158:polysaccharide C-substance (Streptococcus)