Journal Publication | Springer Link: Monitoring renal function in kidney transplant recipients using UVP-TOF-MS exhaled breath analysis

The article "Assessment of an Enhanced Breath Test Using Ultraviolet Photoionization Time of light Maspectometry for the Monitoring of Kidney Transplant Recipients" jointly completed by Chengdu Organ Transplantation Center, West China Fourth Hospital, Department of Urology at West China Hospital of Sichuan University, School of Chemistry at Sichuan University, West China School of Public Health at Sichuan University, and School of Mechanical Engineering at Sichuan University was publicly published on Springer Link in June 2023. Duan Yixiang, Chairman of Chengdu Ailiben Technology, Yang Yanting, General Manager, and Zhao Zhongjun, Director of Mass Spectrometry Department, participated in the completion.

Original link: https://link.springer.com/article/10.1186/s43556-023-00130-6

Summary

Continuous monitoring of immune suppression status, infection, and complications is necessary for kidney transplant (KTx) recipients. Traditional monitoring methods include blood sampling and kidney biopsy, which have the disadvantage of incurring huge medical costs and physical trauma. Therefore, it is extremely necessary to find a cheaper and less invasive monitoring method. This article believes that exhaled breath analysis has the potential to become a feasible tool for monitoring kidney transplantation. This study adopted a prospective specimen collection and retrospective blind evaluation strategy, collecting exhaled breath samples from 175 kidney transplant recipients at West China Hospital and detecting them through online ultraviolet photoionization time-of-flight mass spectrometry (UVP-TOF-MS). The classification model based on exhaled breath analysis performed well in classifying the normal and abnormal values of creatinine, glomerular filtration rate (eGFR), blood urea nitrogen (BUN), and tacrolimus, with AUC values of 0.889, 0.850, 0.849, and 0.889, respectively. Regression analysis showed that exhaled breath analysis had an impact on clinical creatinine levels eGFR、BUN、 The predictive ability of tacrolimus levels showed a good correlation (p<0.05) between the predicted values obtained by the regression model and the clinical true values. The results of this study indicate that using UVP-TOF-MS based on exhaled breath analysis for monitoring kidney transplant recipients is feasible and accurate, which may have profound implications for future clinical screening.

呼出气体收集

The investigators collected all exhaled gas samples according to the collection plan. To collect alveolar air, subjects were required to exhale into a BIO-VOC breath sampler. The sampler expelled dead space air from the oral cavity and upper respiratory tract, while retaining the final breath gas (150mL), which was then transferred to a 0.5L Tedra sampling bag. Each patient was required to collect three consecutive exhaled breaths. In order to eliminate environmental factors, indoor air from the same day was also collected as a negative control. All exhaled breath tests are conducted on the same day as the collection date.

UVP-TOF-MS

Ultraviolet photoionization time-of-flight mass spectrometry (UVP-TOF-MS, developed by Chengdu Ailiben Technology Co., Ltd.) uses a krypton lamp as the ionization source to generate photons with an energy of 10.6eV. The compounds entering the ion source (most VOCs have an electric potential lower than 10.6eV) absorb the photon energy to form cations (M+), which then enter the time-of-flight mass analyzer for mass spectrometry analysis.
UVP-TOF-MS is an online mass spectrometer with a very simple sample introduction and detection process, without the need for pretreatment. Mass spectrometry is in a vacuum state with a vacuum degree of 500Pa. When detecting samples, gas components are automatically absorbed into the ion source and ionized. Mass spectrometry can achieve a signal acquisition time of 1-60s, which is related to the degree of signal accumulation. The longer the acquisition time, the higher the signal.

UVP-TOF-MS series products

【UVP-TOF-MS 2000 LITE】

VOCs real-time online monitoring time-of-flight mass spectrometer

The vehicle mounted time-of-flight mass spectrometer is suitable for real-time online monitoring of pollutants in the ambient air, hazardous chemicals in public security sites, and toxic and harmful substances in water bodies. As a convenient analysis tool, it has excellent sensitivity and measurement accuracy. The instrument can be configured with different sampling devices to meet various daily testing needs. The instrument is equipped with analysis software that can quickly and directly read the collected data.

【UVP-TOF-MS   2000 PLUS】

VOCs real-time online monitoring time-of-flight mass spectrometer

UVP-TOF-MS 2000 PLUS is an online real-time analysis and monitoring mass spectrometer for volatile organic compounds (VOCs). This instrument has the ability to perform high-throughput full component, real-time online, rapid and accurate quantitative analysis of gaseous VOCs. The organic combination of time-of-flight mass spectrometry technology and composite photoionization technology has broken through the bottlenecks of traditional VOCs detectors in terms of analysis speed, operational difficulty, and analysis accuracy. It can be widely used in various fields such as petrochemicals, environmental monitoring, food and drug, process monitoring, quality control, biomedical research, etc.