LJUBLJANA, SLOVENIA – A point-of-care presepsin measurement in the emergency department displayed powerful accuracy for early rule-out of invasive bacterial infection in infants less than 3 months old presenting with fever without a source, based on results of a phase 3 multicenter Italian study.
“P-SEP [presepsin] is a promising new biomarker. P-SEP accuracy for invasive bacterial infection is comparable to procalcitonin, even though P-SEP, like procalcitonin, is probably not accurate enough to be used as a stand-alone marker to rule-in an invasive bacterial infection,” Luca Pierantoni, MD, said in presenting the preliminary study results at the annual meeting of the European Society for Paediatric Infectious Diseases.
The presepsin test is a rapid point-of-care test well-suited for the ED setting, with a cost equal to that of point-of-care procalcitonin.
Presepsin is a form of soluble CD14 that is released from the surface of macrophages, monocytes, and neutrophils when these immune cells are stimulated by pathogens. “We think it may be a reliable diagnostic and prognostic marker of sepsis in adults and neonates,” explained Dr. Pierantoni of the University of Bologna, Italy.
Indeed, studies in adults suggest presepsin has better sensitivity and specificity than other biomarkers for early diagnosis of sepsis, and that it provides useful information on severity and prognosis as well. But, Dr. Pierantoni and his coworkers wondered, how does it perform in febrile young infants?
The Italian study was designed to address an unmet need: Fever accounts for about one-third of ED visits in infants up to age 3 months, 20% of whom are initially categorized as having fever without source. Yet ultimately 10%-20% of those youngsters having fever without source are found to have an invasive bacterial infection – that is, sepsis or meningitis – or a severe bacterial infection such as pneumonia, a urinary tract infection, or an infected umbilical cord. The sooner these infants can be identified and appropriately treated, the better.
The study enrolled 284 children less than 3 months old who had fever without cause of a mean 10.5 hours duration and presented to the emergency departments of six Italian medical centers. Children were eligible for the study regardless of whether they appeared toxic or well. Presepsin, procalcitonin, and C-reactive protein levels were immediately measured in all participants. Ultimately, 5.6% of subjects were diagnosed with an invasive bacterial infection, and another 21.2% had a severe bacterial infection.
Using a cutoff value of 449 pg/mL, P-SEP had good diagnostic accuracy for invasive bacterial infection, with an area under the receiver operating characteristics curve of 0.81, essentially the same as the 0.82 value for procalcitonin. P-SEP had a sensitivity and specificity of 87% and 75%, respectively, placing it in the same ballpark as the 82% and 86% values for procalcitonin. The strong point for P-SEP was its 99% negative predictive value, as compared to 91% for procalcitonin. The positive predictive values were 17% for P-SEP and 20% for procalcitonin.
In response to an audience question, Dr. Pierantoni speculated that the best use for P-SEP in the setting of fever of unknown origin may be in combination with procalcitonin rather than as a replacement for it. The research team is now in the process of analyzing their study data to see if that is indeed the case.
He reported having no financial conflicts regarding his study, conducted free of commercial support.