Advancing the Care of Critically Ill Patients with Multiplex Analysis

Extracorporeal membrane oxygenation (ECMO) is a life-saving technique used to manage cardiopulmonary failure that is resistant to conventional medical and surgical therapies. Despite advances in ECMO equipment, bleeding and thrombosis remain significant complications. While efforts to improve anticoagulation management have been made, discovering alternatives to modern standards of practice remains a priority. 

Researchers at the University of Queensland’s Critical Care Research Group (CCRG) are at the forefront of investigating novel methods of anticoagulation to reduce mortality associated with extracorporeal support. One area of focus is the use of readily available compounds, such as nitric oxide (NO). 

In a recent study on anti-thrombotic therapy for extracorporeal life support (ECLS), Margaret Passmore, Laboratory Manager at CCRG, aimed to broaden her team’s understanding of the effects of nitric oxide on hemostasis, platelet activation, and inflammatory pathways during extracorporeal support. 

The study utilized two separate ex vivo models: an ECMO model and a cardiopulmonary bypass (CPB) model. With limited patient samples, the need to extract maximum information while being judicious with available samples was critical. This is where Luminex® multiplex assays from R&D Systems proved instrumental. 

“Our lab runs a lot of commercial ELISAs as well as ‘in-house’ ones that we have developed,” says Passmore. “The issue is always sample volume—particularly for studies that involve critically ill patients in the ICU. Once the sample is used up, there is no going back or adding another protein that you might be interested in.” 

For this study, researchers used Luminex assay panels targeting ADAMTS-13, P-selectin, and MPO. In both the ECMO and CPB models, the addition of nitric oxide to heparin did not consistently produce a significant anticoagulated effect over and above that of unfractionated heparin (UFH) alone. These findings along with other insights uncovered in the study will help researchers deepen their understanding of how minimum blood flow rates affect hemolysis and coagulation, which is especially relevant during ECMO weaning. 

In this case, the ability to analyze multiple analytes in a single assay allowed researchers to be judicious with materials while generating high-quality data quickly. 

“Multiplexing means we can look at multiple proteins simultaneously, eliminating any variations that might occur by running the assays separately,” says Passmore. “Crucially, we can do this with a very small sample volume, as oftentimes the availability of patient plasma is extremely limited.” 

The ease of use and transparency of the Luminex assays also proved to be an important benefit for the CCRG research team. 

“The time it takes to run the assays is a significant factor for us,” Passmore says. “With the Luminex assays, the protocol is very easy to follow, and everything is standardized across all the kits, which makes them simple to use. The results also proved to be remarkably consistent and reliable.” 

With access to the right analytical tools, Passmore and her team can continue to enhance their understanding of extracorporeal life support, advancing their mission of improving patient outcomes and aiding clinical decision-making. 

Luminex® is a Registered Trademarks of Luminex Corporation.