Indirect immunofluorescence in autoimmune diseases: assessment of digital images for diagnostic purpose.
BACKGROUND
The recommended method for antinuclear antibodies (ANA) detection is indirect immunofluorescence (IIF). To pursue a high image quality without artefacts and reduce interobserver variability, this study aims at evaluating the reliability of automatically acquired digital images of IIF slides for diagnostic purposes.


METHODS
Ninety-six sera were screened for ANA by IIF on HEp-2 cells. Two expert physicians looking at both the fluorescence microscope and the digital images on computer monitor performed a blind study to evaluate fluorescence intensity and staining pattern. Cohen's kappa was used as an agreement evaluator between methods and experts.


RESULTS
Considering fluorescence intensity, there is a substantial agreement between microscope and monitor analysis in both physicians. Agreement between physicians was substantial at the microscope and perfect at the monitor. Considering IIF pattern, there was a substantial and moderate agreement between microscope and monitor analysis in both physicians. Kappa between physicians was substantial both at the microscope and at the monitor.


CONCLUSIONS
These preliminary results suggest that digital media is a reliable tool to help physicians in detecting autoantibodies in IIF. Our data represent a first step to validate the use of digital images, thus offering an opportunity for standardizing and automatizing the detection of ANA by IIF.
Rigon
Amelia
A
Department of Clinical Medicine, Immunology, and Rheumatology, University Campus Bio-Medico, Rome, Italy. a.rigon@unicampus.it
Soda
Paolo
P
Zennaro
Danila
D
Iannello
Giulio
G
Afeltra
Antonella
A
D000293:Adolescent; D000328:Adult; D000368:Aged; D000974:Antibodies, Antinuclear / Q000097:blood; D001327:Autoimmune Diseases / Q000097:blood / Q000175:diagnosis*; D019084:Fluorescent Antibody Technique, Indirect / Q000379:methods*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008856:Microscopy, Fluorescence; D008875:Middle Aged; D015588:Observer Variation
D000974:Antibodies, Antinuclear