Effect of ANA positivity on clinical picture of the JIA: should ANA positive JIA be classified as a different group? - Gok Faysal; Kasapcopur Ozgur; Poyrazoglu Hakan; Erguven Muferet; Unsal Erbil; Bilginer Yelda; Turker Turker; Demirkaya Erkan; Polat Adem; Ozen Seza (BMC, 2011)