Temporomandibular Joint Arthritis Development Influencing Factors, Clinical and Radiologic Symptoms in Children with Juvenile Idiopathic Arthritis. Summary of the Doctoral Thesis

Abstract

Juvenile idiopathic arthritis (JIA) is the most frequent rheumatologic disease in childhood. Any joint can be involved and also temporomandibular joints (TMJ). Longterm consequences of inflammation in these joints can be growth disturbancies with changes in shape and appearance and functional impairment of dentofacial region what in turn can lead to reduced quality of life. Magnetic resonance imaging (MRI) with contrast enhancement is the golden standard for diagnostics of TMJ arthriti. It is invasive and expensive method. To clarify those JIA patients who have indications for MRI it is important to understand factors what influence development of TMJ arthritis and also to know what subjective and/or objective symptoms are reflecting MRI findings. The objective of our study was to determine factors what influence development of TMJ arthritis including demographic, disease characterising clinical, laboratory and genetic factors and also to determine those clinical – subjective and objective symptoms what are connected with radiological symptoms. The study was prospective, cross sectional study consisting from four parts: 1) demographic and disease characterising clinical data of JIA patients group where analysed; 2) to determine factors what influences TMJ arthritis development different factors, including HLA II class alleles where analysed in two main study groups – with MRI findings consistent with TMJ arthritis and those without signs of arthritis in MRI; 3) patients subjective and objective TMJ symptoms where analysed in connection with MRI; 4) MRI results where analysed and compared in patients with TMJ arthritis symptoms and without them (asymptomatic patients). 91 JIA patients where included in the study to whom MRI of TMJ with contrast enhancement was done from years 2010 to 2015. 80 patients had subjective and/or objective TMJ arthritis symptoms and 11 JIA patients without symptoms where included. Factors what influence TMJ arthritis development including HLA II class alleles where analysed in two main groups according to MRI findings – 72 patients had MRI findings consistent with TMJ arthritis (MRI positive group) and 19 patients where with no arthritis signs in MRI (MRI negative group). HLA II class alleles DRB1, DQA1, DQB1 where genotyped in 91 JIA patients group and 100 healthy controls. From all demographic, disease characterising clinical and laboratory factors the only one who was statisticaly significant higher in MRI positive group was C-reactive protein (CRP). We found that there is genetic predisposition for development of TMJ arthritis. Till this there has been no studies about HLA II class alleles in JIA patients with TMJ arthritis. In our study risk for development of TMJ arthritis was found to be in patients with alleles DRB1*07:01, DRB1*13:01, DRB1*15:01. Alleles DRB1*08:01, DRB1*16:01, DRB*17:01 and DQB1*06:01 where found to be associated with less risk for development of TMJ arthritis. Alleles DQA1*05:01, DQB1*03:01 and DRB*11:01 were found to be connected with less risk for chronic inflammatory signs development in TMJ. It was found that there where more subjective and objective clinical symptoms in the group with active and chronic inflammatory signs combination in MRI of TMJ. Demographic, clinical and laboratory factors were analysed using logistic regression model and it was found that objective signs count predict positive MRI findings- if objective findings increased by one unit, probability for positive MRI findig was 2,3. There were more patients with active and chronic inflammatory signs in MRI of TMJ in the group of symptomatic patients than in patients with no subjective and/or objective TMJ arthritis signs. The study will help in the diagnostics of TMJ arthritis in JIA patients what further will help to decide about the treatment.