Evaluation of Neutrophil Gelatinase-Associated Lipocalin in Children with Sydenham's Chorea Accompanying Valvular Regurgitation

Abstract

Background Acute rheumatic fever (ARF) is a nonsuppurative complications of Group A β-hemolytic streptococcal (GABHS) infection due to a delayed immune response. Sydenham's chorea (SC) is an important neurological manifestation of ARF, and heart involvement is seen in a large proportion of patients with SC. The immune system has a crucial role in initiating and spreading inflammation, which causes tissue damage in ARF. Aim The purpose of this study was to investigate urine neutrophil gelatinase-associated lipocalin (NGAL) as a biomarker for kidney injury in children with rheumatic chorea accompanying valvular involvement. Materials and Methods Twenty-eight consecutive children with SC accompanying evidence of valvular involvement, and 30 nonrheumatic, age- and sex-matched healthy children were included in the study. Cardiac evaluations were performed, and urinary NGAL, micro-total protein and creatinine levels were measured in all participants. Results Age, gender, weight, and height were similar in the patients and controls. Twenty-three patients had isolated mitral regurgitation, and five patients had mitral and aortic regurgitation. While there was no statistically significant difference between the urine creatinine and micro-total protein levels in patients and controls, the patient group demonstrated a significantly higher mean urine NGAL level (18.01 ± 7.9 vs. 3.22 ± 1.4, p = 0.002) and mean urine NGAL/creatinine ratio (2.80 ± 1.9 vs. 0.33 ± 0.1, p = 0.008). However, there were no correlations between severity of chorea and urinary NGAL or urinary NGAL/creatinine ratio, there were significant positive correlations between severity of valvular regurgitation and urinary NGAL (r = 0.751, p < 0.001) and urinary NGAL/creatinine ratio (r = 0.694, p < 0.001). Conclusion The present study revealed that urinary NGAL level and urinary NGAL/creatinine ratio were higher in patients with SC accompanying valvular involvement. The results obtained from this study suggest that ARF may cause subclinical renal injury in patients with intense and prolonged cellular immune response leading to chorea and carditis.