Drs. Rafael Artuch and Xavier Rosell from IRSJD are collaborating on a project with the Autonomous University of Barcelona, which has developed a new device that enables real-time monitoring of blood ammonia levels at the patient’s bedside. The experimental device will facilitate the monitoring of liver diseases and other hereditary metabolic disorders and may become a cost-effective alternative to current monitoring systems.
Ammonia is a biomarker used to diagnose various rare hereditary metabolic disorders, such as primary urea cycle disorders and various organic acidemias, as well as other metabolic and environmental conditions that affect liver function with secondary dysfunction of the urea cycle. It is also useful for the study and monitoring of various liver diseases (conditions that affect normal liver function) caused by alcohol consumption, substance abuse, medications, and other environmental factors.
In all these diseases, excess ammonia poses a health risk to the patient. Values exceeding 200 micromoles per litre of blood are considered severe episodes of hyperammonemia (high blood ammonia concentration), which can cause irreversible neurological damage and even death if levels surpass 500 micromoles per litre. Therefore, early and real-time diagnosis is crucial to minimize the impact of a hyperammonemia episode on neurological functions. Currently, patients diagnosed with conditions associated with hyperammonemia must periodically travel to their reference hospital for a blood test, which must then be processed and analyzed in the laboratory.
Researchers from the Research Group on Sensors and Biosensors (GSB) of the Department of Chemistry at the UAB, in collaboration with the Sant Joan de Déu Research Institute, have developed a point-of-care analyser for blood ammonia monitoring that will enable decentralized measurements at the patient’s side, outside hospital laboratories where traditional equipment is used.
The new device aims to decentralize ammonia measurements, making them possible in smaller healthcare centres with direct blood sampling, without the need for prior processing. This will increase monitoring points, simplify the process, and reduce the time required for medical decision-making.
Validation at Hospital Sant Joan de Déu Barcelona
The research team is refining a prototype to function under semi-autonomous conditions. Once operational, all ammonia samples analyzed daily at Hospital Sant Joan de Déu Barcelona using the conventional method will be compared with measurements from the newly developed device. However, Puyol warns that “hundreds of samples will be needed to validate the final point-of-care analyser prototype. It will then need to be industrialized before being brought to market.” Several stages remain before this can happen, but it is expected to become an affordable device that will facilitate liver disease monitoring even in developing countries.
How the device works
The device uses a microfluidic platform that integrates a potentiometric sensor as a detection system and a gas separation membrane. This allows for the automatic separation of ammonia in the form of ammonia gas from the rest of the complex blood matrix, achieving selective detection free from all types of interferences. This ensures precise and accurate determination of blood ammonia concentration in whole blood rather than plasma, which is the medium used in conventional analyses of this parameter.
The research, led by investigators Julián Alonso-Chamarro and Mar Puyol Bosch, from the UAB’s Group of Sensors and Biosensors, is the result of the R&D+I Proof of Concept project (PDC2021-121558-I00). It has been developed with the collaboration of researchers Rafael Artuch, coordinator of the Metabolic and Mitochondrial Medicine Group at IRSJD, and Javier Rosell, coordinator of the Medical Technologies: Instrumentation and eHealth Group at IRSJD. This research has the support and participation of the Fundación PKU-OTM (phenylketonuria and other hereditary metabolic disorders). The system’s validation is being conducted at Hospital Sant Joan de Déu in Barcelona.
More information via: www.irsjd.org