Abstract:

Objective To evaluate EUROPattern auto-reading system（EPA） for the determination of anti-nuclear antibody（ANA） by indirect immunofluorescence（IIF）. Methods Biochips coated with HEp-2 cells and monkey liver cells by IIF were used to determine serum ANA in 836 cases of suspected autoimmune diseases（AID）. The fluorescence patterns were recognized by EPA and manual visual interpretation in parallel. The consistency was evaluated. Results The consistency rate was 96.29%（K=0.92,P<0.05） between EPA and manual visual interpretation regarding positive/negative classification. The results of manual visual interpretation were as standard,and the sensitivity and specificity of EPA were 99.70% and 94.02%. Through Spearman correlation analysis,there was a positive correlation between the 2 methods（r=0.93,P<0.05）. The consistency rates of single-pattern recognition and mixed-pattern recognition between the 2 methods were 93.46% and 91.78%,respectively. The consistency rates of the 2 methods for antibody titer evaluation were 90.95% and 94.03%. The coefficient of variation of negative control was 0.00%,that of weak positive control was 2.44%,and that of positive control was 1.78%. Conclusions EPA agrees well with manual visual interpretation,and it takes the advantages of automation,standardization and saving labor,as well as obtains practical significance for improving the diagnosis of AID.

Key words: EUROPattern auto-reading system, Anti-nuclear antibody, Indirect immunofluorescence