[Study of critical levels of 3 antistreptococcal antibodies by data analysis]

Prinqual, a new statistical data-analysis method was used to determine the critical titers of antistreptolysin O (ASLO), anti-DNase B (ADB) and antistreptokinase (ASK) in the sera of 104 patients with suspected streptococcal infection and 121 blood-donors. The whole range from pathological to normal was thus covered, thereby avoiding bias concerning the proportion of normal titers in a control population. Another advantage of the method was that the titers of the 3 antibodies were considered simultaneously and the semi-quantitative results of serological tests were avoided. It appeared from this study that the upper limits of normal values were: ASLO, 100 U; ADB, 240 U and ASK, 40 U. The first probably pathological values were: ASLO, 150 U; ADB, 480 U and ASK, 320 U. These results are compared with those available in the literature.