New research shows that when lung transplantation begins to fail, the electronic nose can be detected with 86% accuracy.
Experts suggest that this discovery can allow doctors to detect in the early stages of lung transplant failure, called chronic allograft dysfunction (Clad), and allow them to provide treatment to prevent the disease from getting worse.
However, the researchers said that more research is needed before eNose can be used in the clinic.
The most important thing is to evaluate whether we can predict or diagnose lung transplant dysfunction at an early stage, so that more successful early treatment may be achieved
Nynke Wijbenga, PhD student and technical physician at Erasmus University Medical Center, Rotterdam Dutch The research was presented at the International Congress of the European Respiratory Society.
She said: “About 50% of lung transplant patients are diagnosed with chronic allograft dysfunction or chronic rejection within five years after transplantation.
“Chronic rejection remains the most important cause of death after lung transplantation, and there is currently no available treatment to reverse it.”
She added: “Once chronic rejection is confirmed, patients can live for one to five years on average.
“For certain patients with advanced chronic rejection, retransplantation may be the last resort.
“Therefore, it is important to evaluate whether we can predict or diagnose lung transplant dysfunction at an early stage, so that more successful early treatment may be achieved.”
It may take several months to diagnose Clad at this time.
Doctor The lung function is tested at each visit, and if it drops to 80% or lower, then they will investigate further to rule out possible causes of response to treatment, such as lung infections.
Chronic rejection can only be confirmed after these investigations, and the decline in lung function lasts for three months.
eNose is a small device that contains sensors for detecting chemical substances called volatile organic compounds (VOC).
These are present in approximately one percent of exhaled breath and may vary due to metabolic processes.
When the patient exhales to eNose, the sensor not only detects the pattern of VOC in the breath, but also corrects the result to take the inhaled ambient air into account.
Using artificial intelligence to analyze the results, the so-called “breath print” can be used to identify a variety of lung diseases.
Researchers recruited 91 lung transplant patients who went to Erasmus MC for outpatient appointments between July and November 2020.
An eNose measurement is taken from each patient and then compared with the diagnosis already made by the patient consultant.
The patients were between 35 and 73 years old, 47% were male, and the median time after lung transplantation was 3.6 years.
The study found that in 86% of cases, eNose was able to distinguish between 68 patients receiving stable lung transplantation and 23 patients with CLAD.
Ms. Wijbenga said: “These results show that eNose is a promising CLAD detection tool.
“However, more research is needed before it can be used clinically.
“We need to evaluate whether repeated measurements on the same patient can provide a more accurate diagnosis, even predicting CLAD before it occurs.
“In addition, we need to confirm our results in other patient groups. Nevertheless, our goal is to develop it as a technique that is widely used throughout Europe.”
The researchers hope that further studies can distinguish between two types of chronic rejection: bronchitis obliterans syndrome (BOS) and restricted allograft syndrome (RAS).
The electronic nose used in the study is SpiroNose manufactured by Breathomix.
