Kidney Week

Abstract: SA-PO391

A Comprehensive Skin Gas Analysis of Substances Related to Uremia

Session Information

• Hemodialysis and Frequent Dialysis - 2
  October 26, 2024 | Location: Exhibit Hall, Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Dialysis

• 801 Dialysis: Hemodialysis and Frequent Dialysis

Authors

• Hashiba, Toyohiro, Division of Nephrology and Endocrinology, Graduate School of Medicine, The University of Tokyo, Bunkyo-ku, Tokyo, Japan

Toyohiro Hashiba, MD, PhD

• Hirakawa, Yosuke, Division of Nephrology and Endocrinology, Graduate School of Medicine, The University of Tokyo, Bunkyo-ku, Tokyo, Japan

Yosuke Hirakawa, MD, PhD

• Yamahara, Hiroyasu, Department of Bioengineering, Graduate School of Engineering, The University of Tokyo, Bunkyo-ku, Tokyo, Japan

Hiroyasu Yamahara, PhD

• Yano, Yasuo, Department of Bioengineering, Graduate School of Engineering, The University of Tokyo, Bunkyo-ku, Tokyo, Japan

Yasuo Yano

• Yamada, Yuka, Department of Bioengineering, Graduate School of Engineering, The University of Tokyo, Bunkyo-ku, Tokyo, Japan

Yuka Yamada

• Tabata, Hitoshi, Department of Bioengineering, Graduate School of Engineering, The University of Tokyo, Bunkyo-ku, Tokyo, Japan

Hitoshi Tabata, PhD

• Nangaku, Masaomi, Division of Nephrology and Endocrinology, Graduate School of Medicine, The University of Tokyo, Bunkyo-ku, Tokyo, Japan

Masaomi Nangaku, MD, PhD

Background

Recent progress in gas-sensing technology has enabled highly sensitive analysis of skin gases associated with body odor, which are collected more continuously and unconsciously than blood or urine. Patients with end-stage kidney disease (ESKD) have a characteristic uremic odor, which fades after initiating kidney replacement therapy. We investigated the possibility of quantitatively evaluating the substances that cause uremia.

Methods

Skin gases were collected by placing a passive flux sampler on the forearm for 20 min (Figure), heating rapidly, and measuring peak intensity by gas chromatography-mass spectrometry. We investigated the changes in gases obtained from the hemodialysis (HD) group before and after the first HD session of patients undergoing incident dialysis. We compared skin gases between the ESKD (HD, non-HD), chronic kidney disease (CKD) stage G2, and the healthy group.

Results

Of the 176 volatile molecules collected from the HD group (N=5), we focused on 27 substances detected in all patients. Five volatile molecules included in 6-methyl-5-hepten-2-one derived from squalene specific to human sebum were detected in all participants: the ESKD (N=11), CKD stage G2 (N=6), and healthy (N=7) groups. In addition, benzaldehyde excreted in the urine as hippuric acid of uremic substances in the blood showed significantly higher intensities in the ESKD group than in other groups (p=0.012).

Conclusion

Although there were individual differences, a comprehensive skin gas analysis was helpful for inter-individual comparisons of uremia-related substances.

The figure shows a passive flux sampler attached to the participant's left forearm to collect the skin gases and a cross-sectional view.

Funding

• Government Support – Non-U.S.