Comparison of radioimmunoassay and indirect hemagglutination for quantitation of antipneumococcal antibodies.
The RIA and IHA methods to quantitate antipneumococcal antibodies of six capsular types (3, 6A, 8, 12F, 14, and 18C) were compared in 30 paired sera 1 month after pneumococcal immunization. Correlation coefficients for titers were significantly different from zero (p less than 0.001) for all types except 14 and ranged from 0.86 for type 3 to 0.45 for type 18C. In sera that showed a twofold or greater rise by RIA, 50% to 83% showed a fourfold or greater rise by IHA, depending on the capsular type. Conversely, in those sera showing an IHA rise of fourfold or more, 79% to 100% showed an RIA rise of twofold or more. IHA titers correlating with RIA titers greater than or equal to 200 ng AbN/ml varied from 1:16 for type 18C to 1:64 for types 3, 8, and 12F.
D000017:ABO Blood-Group System; D000907:Antibodies, Bacterial / Q000032:analysis*; D006386:Hemagglutination Tests; D006801:Humans; D011135:Polysaccharides, Bacterial / Q000276:immunology*; D011863:Radioimmunoassay; D013296:Streptococcus pneumoniae / Q000276:immunology*
D000017:ABO Blood-Group System; D000907:Antibodies, Bacterial; D011135:Polysaccharides, Bacterial