[Assay of human anti-exoproteins to group A streptococci by microhaemagglutination: correlation with anti-streptolysin O and various anti-enzymes (author's transl)].

A microhaemagglutination test in disposable U plates has been devised for rapid, quantitative evaluation in antistreptococcal antibodies in human sera. Fresh or freeze-dried glutaraldehyde-treated sheep erythrocytes sensitized with over fifteen extracellular proteins released by group A Streptococcus pyogenes including streptolysin O, deoxyribonucleases, hyaluronatelyase, streptokinase and nicotinamide dinucleotide glycohydrolase were used. Haemagglutination and anti-streptolysin O (ASLO) titers were determined in parallel on 434 serum specimens from 123 healthy subjects ("controls") and 311 patients with a history of supposed or evident streptococcal infection. The titration of the four above-mentioned anti-enzyme antibodies has also been made on about 100 sera from both groups. Haemagglutination titre (HT) was less than 800 in control sera. By contrast it was greater than 800 up to 12 800 in patients specimens. Very good correlation was found between HT on the one hand and ASLO or anti-SK, anti-HA and anti-NADase antibodies on the other hand. HT and anti-DNase B antibodies were less correlated. Haemagglutination titres appear to rise earlier than serological titres of conventional streptococcal antibodies. The haemagglutination test described may be particularly helpful as a rapid serologic indicator of streptococcal infections and more reliable than the titration of ASLO alone, or of any one of anti-enzyme antibodies.