Analyzing ANA connection with HLA B27 allele types and therapy efficacy in homogeneous JIA type groups, no credibility were found, so we may assume, that ANA most probably indicates the prognosis of the disease and not disease severity, like it was already proved in rheumatology with other autoimmune diseases, when, for instance, autoantibody - positive RF indicates to a prognosis of worsening and faster progressing course of disease in a case of seropositve JIA [10]. This evidence concerns the gene MRAP and autoimmune disease.