Aim: The aim of this study was to introduce a micromeritic procedure (a statistical approach for small objects) in indirect immunofluorescence assay (IFA) to find objective quantitative parameters of antinuclear antibody (ANA) patterns which could support a diagnosis of auto-immune diseases.
Materials and methods: Sera of patients with systemic autoimmune diseases, McCoy-Plovdiv serum-free cell line, goat anti-human immunoglobulin-G FITC-conjugate, fluorescent microscope, computer-assisted digital image processing, analysis using a micromeritic procedure, ANOVA.
Results: Three ANA fluorescent patterns (homogeneous, rim and speckled) were analyzed by the micromeritic procedure. Parameters for the image brightness of the pixels (pixel grey value) were obtained and discussed as objective characteristics of fluorescent patterns: maximum ANA-linkage volume and surface density were established for the objects with speckled localization pattern.
Conclusion: The micromeritic method for getting objective quantitative values of ANA fluorescent patterns in indirect immunofluorescent assay might be a valuable tool aiding in immunological diagnosing if integrated in a laboratory software package.