EARLY DIAGNOSIS OF JUVENILE ANKYLOSING SPONDYLOARTHRITIS

Juvenile ankylosing spondyloarthritis is a disease with hereditary predisposition, characterized by chronic inflammation in peripheral joints as well as those of the axial skeleton. About 47% of patients having juvenile ankylosing spondyloarthritis in childhood are subsequently disabled. Today, there is no any single specific classification of ankylosing spondyloarthritis. According to the clinical manifestations and laboratory indices, it could be regarded as an enthesitic variant of juvenile idiopathic arthritis, according to Durban Classification 1997 (International League of Associations for Rheumatology), and in presence of radiologically confirmed sacroiliitis - to juvenile ankylosing spondylitis, according to classification of Garmisch-Partenkirchen of 1987. Juvenile ankylosing spondyloarthritis also fits into the criteria of peripheral form of spondyloarthritis according to Assessment of Spondyloarthritis International Society criteria. First of all, such difficulty in classification is associated with the fact that in children and adolescents, as distinct from adults, the peripheral joint syndrome dominates at the onset of the disease, and the spine involvement occurs later, after several years and, sometimes, only in adulthood. The peculiarities of the clinical picture, the anamnestic and genetic data, magnetic-resonance tomographic and radiographic (X-ray) findings in the sacroiliac joints were analyzed in different periods of ankylosing spondyloarthritis in the study conducted at the Children's Rheumatology Department of the First MSMU after I.M. Sechenov. A comparison of the sensitivity and specificity of these two methods of visualization was conducted for detection of acute and chronic signs of sacroiliitis in juvenile spondyloarthritis. The study confirmed that radiography of sacroiliac joints retains the value as a screening method for diagnosis of sacroiliitis in the later stages of juvenile ankylosing spondyloarthritis, while MRI is a method of choice for the detection of sacroiliitis at the early stages of the disease. With the help of MRI it is possible to diagnose juvenile spondyloarthritis at the pre-radiographic stage of joints' affection, to start the therapy on time, and possibly to avoid the development of structural changes and early disability of young patients. Magnetic resonance imaging allows controlling the process activity in different periods of its development.