COMPARISON OF NEPHELOMETRIC AND HEMOLYTIC TECHNIQUES FOR DETERMINATION OF ANTISTREPTOLYSIN-O ANTIBODIES

The sensitivity of a newly devised nephelometric method for determinin g antistreptolysin O antibodies was compared with the hemolytic inhibi tion assay. Three hundred-thirty single serum samples from children wi th and without evidence of group A streptococcal infection were analyz ed by the two techniques. The nephelometric method results correlated well with those of the reference test (concordance: r = 0.88). Further more, 134 pairs of acute and convalescent phase sera from patients wit h culture-proven GAS infection and 50 pairs from children who served a s control subjects were examined. The nephelometric assay was more sen sitive in detecting significant ASO antibody rises than the hemolytic assay. The automated nephelometric method appears to be a much simpler and sensitive procedure for testing ASO antibodies.