Immune Profiling Panel: a proof of concept study of a new multiplex molecular tool to assess the immune status of critically-ill patients

Abstract

BackgroundCritical illness such as sepsis is a life-threatening syndrome defined as a dysregulated host response to infection and is characterized by patients exhibiting various impaired immune profiles. In the field of diagnosis, a gap still remains in identifying the immune profile of critically-ill patients in the ICU. The availability of an immune profiling tool holds a great potential in providing patients at high risk with more accurate and precise management. In this study, a multiplex immune profiling panel prototype was assessed for its ability to semi-quantify immune markers directly from blood, using the FilmArray® System.ResultsThe Immune Profiling Panel (IPP) prototype consists of 16 biomarkers that target both the innate and adaptive immune responses, pro- and anti-inflammatory mediators as well as genes involved in diverse regulatory pathways. The analytical studies carried out on healthy volunteers showed minimal inter- and intra-variability in testing the samples across the tested lots. The majority of the assays were linear with an R2 higher than 0.8. Results from the IPP pouch were comparable to qPCR and were within the limits of agreement. Finally, quantification cycle values of the target genes were normalized against reference genes to account for the different composition of cells among specimens. The use of the selected panel of markers in IPP demonstrated various gene modulations that could distinctly differentiate three profiles: healthy, borderline mHLA-DR septic shock patients and low mHLA-DR septic shock patients.ConclusionThe Immune Profiling Panel allowed host transcriptomic analysis of immune response biomarkers directly from whole blood in less than an hour. The use of IPP showed great potential for the development of a fully automated, rapid and easy-to-use immune profiling tool, enabling the stratification of critically-ill patients at high risk in the ICU.

Comparison of host immune responses to LPS in human using an immune profiling panel, in vivo endotoxemia versus ex vivo stimulation

“…ulated ex vivo samples) were tested with IPP prototype 18 according to manufacturer's instructions. Briefly, the pouches were hydrated with the hydration solution supplied with the kit.…”

“…A 100 μL of either PAXgene mix or TruCulture mix were mixed with approximately 800 µL of the lysis buffer provided with the kit and directly injected into the pouch and ran on FilmArray 2.0 and FilmArray Torch instruments (BioFire, Inc., Salt Lake City, UT, USA). Results were delivered in less than 1 hour and the normalized expression values of markers were computed 18 .…”

“…In this study, we used a tool we recently described: the Immune Profiling Panel (IPP), a multiplex molecular tool using the FilmArray system 18 , to assess the host response to LPS stimulation, using 38 immune-related transcriptome markers in vivo. The panel of markers targeted several immune functions, cell surface markers and the two arms of the immune response including inflammatory and anti-inflammatory responses.…”