Kidney Week

Abstract: TH-PO1083

Clinical Application of Urinary Podocyte mRNA: Effect of Preanalytical Conditions and Normalization Strategies on Measurement Reproducibility

Session Information

• Pathology and Lab Medicine
  October 22, 2026 | Location: Exhibit Hall A, Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Pathology and Lab Medicine

• 1700 Pathology and Lab Medicine

Authors

• Fukuda, Akihiro, Oita Daigaku Igakubu Fuzoku Byoin, Yufu, Oita Prefecture, Japan

Akihiro Fukuda, MD, PhD

• Suzuki, Miho, Oita Daigaku Igakubu Fuzoku Byoin, Yufu, Oita Prefecture, Japan

Miho Suzuki, MD

• Kurimoto, Ryo, Oita Daigaku Igakubu Fuzoku Byoin, Yufu, Oita Prefecture, Japan

Ryo Kurimoto, MD

• Mitsue, Chisato, Oita Daigaku Igakubu Fuzoku Byoin, Yufu, Oita Prefecture, Japan

Chisato Mitsue, MD

• Uchida, Hiroki, Oita Daigaku Igakubu Fuzoku Byoin, Yufu, Oita Prefecture, Japan

Hiroki Uchida, MD

• Kudo, Akiko, Oita Daigaku Igakubu Fuzoku Byoin, Yufu, Oita Prefecture, Japan

Akiko Kudo, MD

• Shibata, Hirotaka, Oita Daigaku Igakubu Fuzoku Byoin, Yufu, Oita Prefecture, Japan

Hirotaka Shibata, MD, PhD

Background

Urinary sediment mRNA is a promising non-invasive biomarker of glomerular injury, but its clinical utility is limited by variability from preanalytical conditions and normalization strategies. This study systematically evaluated preanalytical factors, identified sources of inter-sample variability, and assessed optimal normalization strategies for clinical application.

Methods

Urine samples from 18 patients with kidney disease were used to examine the effects of freeze–thaw cycles, collection conditions (first-morning vs spot urine), storage temperature, and storage duration on urinary sediment podocin and AQP2 mRNA. In addition, urinary sediment mRNA was measured in 234 healthy adults to assess the impact of normalization using urinary creatinine and urinary sediment AQP2 mRNA on inter-sample variability.

Results

Freeze–thaw processing and prolonged room-temperature storage significantly reduced urinary sediment mRNA levels, whereas stability was maintained at 4°C with prompt processing. In healthy adults, urinary sediment mRNA showed marked inter-sample variability. Urinary creatinine had low variability but did not sufficiently reduce podocin mRNA variability. Conversely, normalization using urinary sediment AQP2 mRNA more effectively reduced inter-sample variability than creatinine (geometric coefficient of variation: 2.94 vs 2.15), supporting its use as a normalization factor.

Conclusion

Urinary sediment mRNA highly sensitive to preanalytical conditions, emphasizing the need for strict sample handling and appropriate normalization strategies. These findings provide a practical framework to improve measurement reproducibility and support the clinical implementation of urinary podocyte markers.

Funding

• Government Support – Non-U.S.