Taken together, pneumonia, bronchitis and tuberculosis – known as LRTIs – are the third largest cause of death worldwide. The lack of treatments is not to blame: existing antibiotics are effective, but they are often misused due to the multiple shortcomings of routine microbiological diagnostic tests. The perfect test method should be fast and accurate. It should allow for the diagnosis of inaccessible infections, avoid false alarms, and be able to deal with evolving microbes. Whilst none of the existing test methods (such as culture, molecular diagnostic and the rapid antigen test) fits the bill for LRTI, the alternative developed by Israeli SME MeMed Diagnostics offers a new approach. “For nearly a decade, in collaboration with leading clinicians around the globe, we have been developing and validating MeMed BV™ – a pioneering host-protein signature that distinguishes between bacterial and viral infections. It harnesses the body’s immune response to infection,” explains Dr Tanya Gottlieb, VP Scientific Affairs at MeMed Diagnostics and coordinator of the Respiratory-ImmunoDx project. “The host-signature is based on measurements of three blood borne immune-proteins: tumour necrosis factor-related apoptosis-inducing ligand (TRAIL), interferon gamma-induced protein-10 (IP-10) and C-reactive protein (CRP).” MeMed BV™ computationally integrates these three proteins to generate a score indicative of the likelihood of a bacterial immune response. Unlike other diagnostic tests, it can tell the difference between bacterial and viral infections, and has been validated in clinical studies enrolling thousands of patients with a sensitivity and specificity reaching over 90 %. Its performance has been demonstrated in both children and adults, across multiple clinical syndromes and pathogens, and irrespective of coloniser presence, from 0 to 7 days after symptom onset. Funding under Respiratory-ImmunoDx allowed the team to conduct one of these clinical studies specifically on LRTI, named OBSERVER. The study, which enrolled a total of 583 patients, consisted in validating the TRAIL/IP-10/CRP signature in adults suspected of carrying infections like bronchitis and pneumonia. Preliminary analysis indicates that the host signature exhibited a sensitivity of 98 %, a specificity of 95 %, a positive predictive value of 91 % and a negative predictive value of 99 %, thereby demonstrating its high performance. The signature was also shown to significantly improve the concordance between the diagnosis at the time of emergency assessment and the ‘true diagnosis’ (reference standard) from 56 % to 87 %. But the project went a step further. Dr Gottlieb and her team developed a compact, easy-to-use point-of-care platform able to measure multiple proteins rapidly with lab-level precision. “The diagnostic system, called MeMed Key™, includes an analyser and a disposable cartridge that contains all the reagents. The underlying chemiluminescence and magnetic particle chemistry is similar to that of large automated immunoassay machines, with a test run time of 15 minutes for measuring the TRAIL/IP-10/CRP signature. This paves the way to application in multiple clinical settings,” she enthuses. While the MeMed BV™ test is compatible with serum – a sample type that demands coagulation and centrifugation – it is only suitable for hospitals, thereby prohibiting wider adoption by physicians. Dr Gottlieb and her team are planning to make MeMed BV™ compatible with small volumes of capillary blood to expand applicability to physician offices, as well as commercialise both tests in Europe and the United States.
Respiratory-ImmunoDx, acute lung infection, antibiotic resistance, MeMed BV, LRTI, pneumonia, bronchitis, diagnostic, point-of-care platform