Background: ImmunoXpert™ is a novel assay that distinguishes between bacterial and viral infections based on the patient’s immune response. It integrates the serum levels of host-proteins (TRAIL, IP-10, and CRP) and computes a bacterial likelihood score. previous study demonstrated 91% concordance rate with a reference standard diagnosis. We incorporated ImmunoXpert™ into the routine workflow at our pediatric department and compared its rate of concordance with the presumed etiology specified by the managing physicians.
Methods: ImmunoXpert™ assay was performed every weekday morning on both admitted and ED pediatric patients, 3 months – 18 years of age. The managing physicians completed a dedicated questionnaire indicating whether they suspected a bacterial or viral infectious etiology. The concordance rate between the assay results and physician assessment were then analyzed.
Results: Over an 18-month period, the assay was performed 230 times per month on average. 295 questionnaires were completed, after the initial history and physical examination; and 40 were completed after the physician was privy to the patient’s complete blood count and chemistry lab results. The analyzed cohort included patients presenting with a variety of suspected acute infectious syndromes. When the presumed etiology was assessed solely on the basis of history and physical examination, 40% of the physicians’ diagnoses were discordant with assay results. However, when CBC and chemistry results were available to the physician prior to questionnaire completion, the discrepancy rates were 30%.
Conclusions: The high concordance (91%) of the ImmunoXpert™ assay with reference standard diagnoses in comparison to the managing physician’s initial assessment (60%) suggests that the assay may facilitate timely and accurate diagnosis of acute infections, even before molecular and microbiological results are available, and may enhance clinical utility by reducing diagnostic testing and antibiotic misuse.
