Kidney Week

Abstract: SA-PO0452

Early Detection of Diabetic Nephropathy via Single-Photon Emission CT (SPECT)/CT Imaging of Intravenously Administered Technetium Tc 99m Tilmanocept

Session Information

• CKM: Clinical - Screening, Population Management, Care Disparities, and Patient-Centered Outcomes
  October 24, 2026 | Location: Exhibit Hall A, Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Cardiovascular-Kidney-Metabolic Health

• 602 Cardiovascular-Kidney-Metabolic Health: Clinical

Authors

• Ginsberg, Charles, University of California San Diego, La Jolla, California, United States

Charles Ginsberg, MD, MA

• Hoh, Carl K., University of California San Diego, La Jolla, California, United States

Carl K. Hoh, MD

• Macedo, Etienne, University of California San Diego, La Jolla, California, United States

Etienne Macedo, MD, PhD, FASN

• Tu, Xin, University of California San Diego, La Jolla, California, United States

Xin Tu, PhD

• Longduriyang, Yvette, University of California San Diego, La Jolla, California, United States

Yvette Longduriyang

• Vera, David R., University of California San Diego, La Jolla, California, United States

David R. Vera, PhD

Background

Diabetes is the leading cause of kidney disease in the United States. Mesangial matrix expansion is an early event in the development of diabetic nephropathy that is not detectable by current biomarkers and requires a renal biopsy for a definitive diagnosis. Tc-99m-tilmanocept binds to mesangial cells via the CD206 receptor.

Methods

Forty-four individuals were divided into four groups based on eGFR. Healthy individuals (Group I, n=25) had eGFRs greater or equal to 60 ml/min/1.73m²; Group II, <60 - ≥45 (n=9); Group III, <45 - ≥30 (n=6); Group IV, <30 (n=4). One hour after an intra-venous injection of ^99mTc-labeled tilmanocept, a SPECT/CT scan of the kidneys was performed. After attenuation-correction and co-registration, transaxial parametric images through the left kidney were generated. This metric, the mesangial function index (MFI), was based on the percent-injected dose per pixel volume and scaled by the subject's body mass index. The highest MFI pixel value within the renal cortex was designated the MFI_max for that subject. Receiver operating characteristics analysis of MFI_max was conducted with healthy Group I subjects (n=12) as disease-negative and all T2 diabetic participants as disease-positive (n=29).

Results

MFI_max parametric cross-sections revealed a statistically significant difference between MFI_max values of non-diabetic (n=12) and type 2 diabetic (n=10) subjects with eGFRs greater than 60 ml/min/1.73ml² (Figure). ROC analysis of the MFI_max (AUC=0.97±0.03) demonstrated higher diagnostic power for diabetes status compared to eGFR (AUC=0.79±0.07), SUVmax (AUC=0.86±0.06), and BMI (AUC=0.70±0.08) indices.

Conclusion

Tilmanocept imaging of the kidney with SPECT/CT was able to differentiate non-diabetic from diabetic kidneys in individuals with preserved renal function and therefore may be a useful tool for the early detection of diabetic nephropathy.

Funding

• NIDDK Support