In February, 2017, FDA approved a new assay (Rt-Qpcr) for Mrna Transcript Immune Biomarkers to detect sepsis. It is a quantitative gene expression assay using reverse transcription polymerase chain reaction to quantify the relative expression levels of host response genes isolated from whole blood.
This test is not widely available, and currently it takes about 6 hours to run the test. However, the makers of the test, immunexpress announced a collaboration with another company, Biocartis. Combined together they will come up with a rapid-PCR testing platform , which can give results in less than 90 minutes. That will make it a valuable tool in diagnosing sepsis.
This test uses polymerase chain reaction (PCR) technology to identify the presence and levels in peripheral blood of four RNA transcripts known to be produced by human bodies during systemic infection. The four gene targets involved — LAMP1(Lysosomal associated membrane protein 1), CEACAM4(Carcinoembryogenic antigen related cell adhesion molecule 4), PLA2G7 (Phospholipase A2 Group 7), PLAC8 (Placenta specific gene 8). These gene targets were chosen after years of testing (see below).
This test was validated by 2 trials, one in the USA and other in Netherlands, with each trial enrolling 249 and 198 patients each. Results were published in American Journal of respiratory and critical care medicine.
In receiver operating characteristic curve analysis, SeptiCyte™ LAB had an estimated area under curve of 0.82-0.89 for discriminating sepsis from non-infectious systemic inflammation. Using a gold standard of consensus of three experts adjudicating patient outcomes, SeptiCyte was 0.97 sensitive for sepsis, equating to a 3% false negative rate. Negative predictive values were reported as 0.89 or higher.
It took years of painstaking work to develop this test. Its shown here.
Once its used in clinical practice, we will have more data and probably it will not be as sensitive or specific as it is in these clinical trials. Still it is another test which hopes to add diagnosis of sepsis, soon available to clinicians.