Evaluation of renal elasticity by shear wave elastography in children with Familial Mediterranean Fever

Background Familial Mediterranean Fever (FMF) is a genetic disorder that can cause kidney damage. Shear wave elastography (SWE), a non-invasive method, was used to evaluate the decrease in renal tissue elasticity as a predictive parameter for amyloidosis. This study aimed to examine the changes in renal elasticity in patients with FMF using the renal SWE measurement method. Methods The present study included 50 pediatric patients diagnosed with FMF. The median SWE values of both kidneys were compared between the groups. Acute phase reactants were also evaluated. Results The SWE measurements (for the left kidney p = 0.007, for the right kidney p = 0.06) and proteinuria levels (p < 0.001) of the patient group were found to be higher than those of the control group. No correlation was observed between the disease activity score and the SWE measurements. Erythrocyte sedimentation rate (p < 0.001), C-reactive protein (p < 0.001) and urine protein/creatinine ratio (p < 0.001) were significantly higher in the remission period compared to the control group, whereas estimated glomerular filtration rate was found to be low in the patient group (p < 0.001), which was considered as an indicator that subclinical inflammation continued in the course of the disease. Conclusions The acute phase reactants were elevated in patients with FMF even in the remission period which indicates that the disease is constantly active and have the potential to cause damage in all organs and tissues. It is thought that this subclinical inflammation may also contribute to increased tissue stiffness, which may serve as a predictor for the development of amyloidosis.