[Problems in the characterization of autoantibodies in patients' sera by microfluorometry as exemplified by...

Attention is called to various problems of subjective differentiation of fluorescence patterns for demonstrating autoantibodies by the indirect immunofluorescent technique. For the objective measurement of the fluorescent intensity, the main problem is the dependence of the measuring results upon the thickness of the tissue sections. The determination of the relationships of the fluorescent intensity in one preparation is independent on the thickness of the section. Using 25 patient sera with antimitochondrial antibodies, it could be shown that the relationship of the fluorescent intensity of various positively reacting tissue areas is not constant, but changes considerably depending on the concentration of the autoantibody in the test solution. Thus, differentiation of subgroups of antimitochondrial antibodies cannot be made using one serum dilution.