Noninvasive Quantitative Evaluation of Proliferative Lupus Nephritis Based on Ultrasonic Viscoelastic Imaging

To evaluate the role of ultrasonic viscoelastic imaging in predicting proliferative lupus nephritis (PLN).

We prospectively used ultrasonic viscoelastic imaging to evaluate 143 patients with lupus nephritis (LN), who underwent kidney biopsies from May 2023 to June 2024. Sixty healthy volunteers served as the control group. Patients were categorized as 90 cases of PLN, and 53 cases of nonproliferative lupus nephritis (nPLN). Ultrasonic viscoelastic imaging was employed to quantitatively analyze kidney cortex elasticity (Emean), viscosity coefficient (Vmean) and dispersion coefficient (Dmean). Semi-quantitative assessment of the lesion tissues was conducted based on the activity index and chronic index scoring system established by the National Institutes of Health (NIH) in 2018. The relationship among clinicopathological, conventional ultrasound factors and viscoelastic parameters was evaluated.

Viscoelastic parameters (Emean, Vmean, and Dmean) significantly differed among the healthy control, PLN, and nPLN groups (all p < 0.05). The viscoelastic parameters (Emean, Vmean, and Dmean) of the PLN and nPLN groups exceeded those of the control group. Vmean and Dmean were considerably greater in the PLN group than in the nPLN group (p < 0.05). Vmean (OR 89.49, p = 0.002), serum creatinine (Scr) (OR 110.57, p = 0.024), and anti-dsDNA (OR 1.0, p = 0.015) were significant predictors of PLN. The combined model's area under curve (AUC) for predicting PLN was 0.83, better than any single indicator (p < 0.05). The peak systolic velocity (PSV) of the interlobar artery was determining factor of Emean (p < 0.05). The estimated glomerular filtration rate (eGFR), activity index, and body mass index (BMI) were determining factors of Dmean, while activity index was the determining factor of Vmean (p < 0.05). Correlation analysis reveals a positive correlation between Vmean and both the activity index and the chronicity index (r = 0.57 and r = 0.34, respectively, p < 0.05), as well as between Dmean and both the activity index and the chronicity index (r = 0.43 and r = 0.20, respectively, p < 0.05).

As a noninvasive examination method, ultrasonic viscoelastic imaging is beneficial for identifying PLN.