[Methodological error in clinical lysozyme determinations]

In 152 sera and 40 synovial fluids of 192 patients from 3 different diagnostic groups the level of muramidase was studied comparatively with the lysoplate method. Despite the similar correlations of mean values and standard deviations of the results in the single groups, en detail these are significantly different. With an increasing mean value of 1 U (mg/l) the standard deviation is elevated by 0.1-0.25 U, for an elevation of s by 1 U mean varied between 3.8 and 9.7 U. This might be of interest for the clinical interpretation esp. of low muramidase values.