Effect of ANA positivity on clinical picture of the JIA: should ANA positive JIA be classified as a different group?

Background

According to ILAR classification, JIA is classified into 7 different categories based on similar characteristic features of each.

Aim

In this study we aimed to investigate whether ANA positive patients in different ILAR categories constitute a homogenous group.

Methods

In this cross-sectional study, patients who had been followed up for at least a 6 month-period were recruited from different centers and registered thorough a web-based registry. Patients were grouped according to their ANA positivity. Clinical and demographic features were compared between ANA positive and negative groups. The results were explored by univariate and multivariate regression analysis (OR, %95 CI).

Results

A total number of 402 JIA patients of which 169 ANA positive and 233 ANA negative were enrolled in the study. The mean age of the diagnosis in ANA negative and positive groups were 4.65 ± 3.48 and 4.01 ± 2.86 respectively; and female-male ratio for ANA negative and positive groups were 1.3 (135/98) and 4.1 (136/33) respectively. The subgroups of the patients according to ILAR classification system are listed in the table.

According to our results of multipl regression analysis, the variables which demonstrated statisticly significant association with ANA presence were female sex (OR =3.763 (2.26-6.27)), uveitis (OR=5.58 (2.21-14.10)), rheumatoid factor positivity (OR=4.07 (1.34-12.36)), high levels of ESR (OR 0.993 (0.985-1.00)) and small joint involvement (OR 0.57 (0.31-1.03)).

Conclusion

Our results indicate that, ANA positive patients classified in different groups by using current ILAR classification system, demonstrate similar clinical and laboratory findings. Thus we suggest that ANA status may be used as a parameter for classification of JIA.

Table 1