Content of natriuretic peptide (NT-proBNP) in patients with juvenile idiopathic arthritis

Abstract

ABSTRACT. As a result of a cascade of immune-inflammatory reactions, the development of a chronic inflammatory process, systemic damage to the endothelium of vessels in rheumatic diseases, and in particular arthritis, are pathological conditions that are associated with the formation of a number of comorbid changes in internal organs and systems. The most significant are changes in the functioning of the cardiovascular system, with the gradual development of chronic heart failure. An informative marker of myocardial dysfunction is an increase in the level of natriuretic peptide (NT-proBNP). Purpose. Determination of the content of NT-proBNP in children with juvenile idiopathic arthritis, taking into account the functional state of the myocardium. Materials and methods. 56 patients with juvenile idiopathic arthritis were examined (polyarthritis - 86%; oligoarthritis - 14%, 17 boys, 39 girls). The average age is 13.28 ± 0.38 years. The duration of juvenile idiopathic arthritis was from 12 to 180 months (68.96 ± 6.29 months). The control group consisted of 46 (27 boys and 19 girls) practically healthy peers of the corresponding age (14.72 ± 0.28 years). The functional state of the heart was determined, namely the parameters of the left and right ventricles: ejection fraction, stroke volume and minute blood volume. The study of NT-proBNP in the blood was carried out by the method of competitive immunoassay on the IMMULITE 2000 Siemens analyzer. The results. The study of the content of NT-proBNP in children with juvenile idiopathic arthritis showed its normal levels (41.12 ± 6.86 pg/l), but in the control group they were significantly lower than in sick children (29.27 ± 5.23 pg/l , p < 0.01). No differences were found in the level of NT-proBNP depending on the gender of the patients, the variant of juvenile idiopathic arthritis and the degree of its activity. Indicators were significantly higher in children 11-14 years old (49.04 ± 10.22 pg/l, p < 0.05) and with disease duration up to five years (57.04 ± 12.37 pg/l, p < 0.05). The study of the functional state of the myocardium in sick children determined a tendency to decrease the contractile function of the myocardium of both the left and right ventricles of the heart against the background of a decrease in the stroke volume of both ventricles, as well as an acceleration of the heart rate. The mean level of NT-proBNP was significantly higher in the group of children with lower left (pt < 0.01) and right ventricles ejection fraction (pM-U < 0.01). Conclusions. The content of NT-proBNP in patients with juvenile idiopathic arthritis remains within normal values, but is significantly higher than in healthy peers (p < 0.01). The highest values of NT-proBNP in patients with juvenile idiopathic arthritis were among adolescents aged 11-14 years (p < 0.05), as well as with disease duration up to five years (p < 0.05). A decrease in the functional state of the myocardium of both ventricles of the heart in patients with juvenile idiopathic arthritis is accompanied by an increase in the content of NT-proBNP, which is the basis for additional examination of the functional state of the heart already in adolescence for the purpose of early prevention of complications.