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Kidney Week

Abstract: SA-PO363

Ultrasound Evaluation of Fibrosis in Pediatric Kidney Transplant Recipients

Session Information

  • Pediatric Nephrology - III
    November 04, 2023 | Location: Exhibit Hall, Pennsylvania Convention Center
    Abstract Time: 10:00 AM - 12:00 PM

Category: Pediatric Nephrology

  • 1900 Pediatric Nephrology

Authors

  • Viteri, Bernarda, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, United States
  • De Leon-Benedetti, Laura S., The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, United States
  • Morales-Tisnes, Tatiana, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, United States
  • Bhatti, Tricia, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, United States
  • Sultan, Laith R., The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, United States
  • Amaral, Sandra, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, United States
  • Otero, Hansel J., The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, United States
Background

To evaluate doppler resistive indices, ultrasound elastography, and contrast ultrasound as imaging biomarkers of fibrosis in pediatric kidney transplants.

Methods

A prospective study of children with kidney transplant and healthy controls was conducted from February 2020 to May 2023. All subjects underwent ultrasound with spectral Doppler to measure resistive indices (RI) and shear wave elastography to assess renal stiffness. RIs were assessed in the upper, interpolar, and lower poles and median elastography values were averaged from 10 regions of interest. Kidney transplant recipients undergoing clinically indicated biopsies underwent contrast-enhanced ultrasound (CEUS) and Time-Intensity Curves were generated. CEUS time to peak, peak enhancement, perfusion index, area under the curve, and mean transit time were examined. All kidney allografts were classified as with interstitial fibrosis and tubular atrophy (IFTA) or without IFTA based on histopathology. Subjects with rejection were excluded.
Kruskall-Wallis was used to compare RI and elastography between the three groups. Dunn test was used for post-hoc analysis. For the CEUS studies, Mann-Whitney analysis was used to compare allografts without vs. with fibrosis.

Results

16 healthy control kidneys were examined among 8 subjects with median age 14.5 yrs. Among 11 kidney allografts, six (54.6%) were from living donors; median recipient age 16 yrs. Of the 11 allografts, 4 (33.3%) had IFTA (all grade 1). We found no difference in resistive indices (p=0.53) between allografts without vs. with fibrosis, or controls. Elastography measures differed between controls and all allografts (p=0.01); but did not differ between allografts with or without fibrosis.
Among subjects with CEUS, mean transit time was the only parameter significantly prolonged in the allografts with fibrosis (vs. those without) (p=0.04).

Conclusion

In this cohort, RIs did not differ between groups. Tissue stiffness, by elastography, differed between controls and allografts but not between those with and those without fibrosis. CEUS detected differences in mean transit time between allografts with vs. without fibrosis, suggesting CEUS may be a sensitive biomarker to detect fibrosis. A larger sample and longitudinal data are needed for validation.

Funding

  • NIDDK Support