Contrast-enhanced ultrasonography for assessing histopathology in pediatric immunoglobulin A nephropathy and Henoch–Schönlein purpura nephritis

Background Glomerular disease, including immunoglobulin A nephropathy (IgAN) and Henoch–Schönlein purpura nephritis, is one of the most common kidney diseases in children. The diagnosis of these diseases depends on pathological biopsy, although this procedure is seriously limited by its invasive and high-risk nature. Objective To investigate the potential of contrast-enhanced ultrasonography (CEUS) for evaluating the histopathological severity of IgAN and Henoch–Schönlein purpura nephritis (HSPN). Materials and methods We investigated a total of 13 children with IgAN and 12 children with HSPN confirmed by renal histopathology. We reevaluated the pathological lesions of the children according to the Oxford classification and the Lee grading system and then all the children underwent CEUS. Using SonoLiver software, we constructed time–intensity curves of CEUS for regions of interest in the renal cortex. We analyzed CEUS quantitative parameters for IgAN and HSPN and used Spearman correlation analysis to examine the correlation between CEUS parameters and clinicopathological indexes in the study cohort. Results The CEUS parameters rise time (RT) and time to peak (TTP) were significantly higher in children with Lee grade IV than in those with Lee grades II or III. Spearman correlation analysis revealed a positive correlation between rise time and time to peak with Lee grade in the overall cohort of children, and a positive correlation between rise time and time to peak and severity of crescents in the Oxford classification scoring system. Conclusion Contrast-enhanced US may be used as a noninvasive imaging technique to evaluate the severity of renal pathology and formation of crescents in children with IgAN and HSPN.