Assesing the Effect of ANA Positivity on Clinical Picture of the Juvenile Idiopathic Arthritis in a Large Cohort of Turkish Ancestry

Erkan Demirkaya, Adem Polat, Turker Turker, Yelda Bilginer, Balahan B. Makay, Erbil Unsal, Muferet Erguven, Hakan Porazoglu, Ozgur Kasapcopur, Nuray A. Ayaz, Harun Peru, Faysal Gok, Cengizhan Acikel, Seza Ozen

Abstract
ABSTRACT
Objectives: According to ILAR classification, JIA is classified into 7 different categories based on similar characteristic features of each. In this study, we aimed to investigate whether ANA positive patients in different ILAR categories constitute a homogenous group in Turkish ancestry of JIA patients.
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 multiple regression analysis, the variables which demonstrated statistically significant association with ANA positivity were female sex (OR =3.763 (2.26-6.27)), presence of uveitis (OR=5.58 (2.21-14.10)) and lower levels of ESR (OR 0.993 (0.985-1.00)) lower number of joint involvement, small joint involvement (OR 0.57 (0.31-1.03)) and hip joint involvement (OR 0.567 (0.520-0.619)).
Conclusion: This study indicates that ANA positive patients who were classified in different subgroups according to current ILAR classification system demonstrate similar clinical and laboratory findings. Our findings support previous findings about this subject and we suggest that ANA status may be used as a parameter for classification of JIA.

Key words: Juvenile idiopathic arthritis, antinuclear antibody, classification, gender, uveitis