Blood biomarkers for personalized treatment and patient management decisions in community-acquired pneumonia.

In patients with community-acquired pneumonia (CAP), blood biomarkers can help to substantially improve individual decisions involving initiation, (de-)intensification, and cessation of antibiotics, and initial risk stratification, site-of-care assignment (outpatient versus ward versus ICU), and discharge. To illustrate these processes, this review summarizes recent findings from trials investigating the use of two hormokines, procalcitonin (PCT) or proadrenomedullin (ProADM), in personalized treatment and management decisions in CAP patients. Many biomarkers from distinct pathophysiological pathways have been evaluated in observational studies. However, only few analytes have been tested for efficacy and safety in numerous, large observational studies or in prospective, randomized, interventional trials. Among the latter, PCT has been demonstrated to be well tolerated and highly effective for monitoring and de-escalating antibiotic therapy. ProADM has shown higher accuracy for short-term and long-term adverse outcome prediction and improves prognostic accuracy when combined with current clinical risk scores, that is, Pneumonia Severity Index, the CURB65 (confusion, uremia, respiratory rate, blood pressure, age at least 65 years) score, and Risk of Early Admission to ICU, compared to applying the respective score alone. ProADM use has - in a pilot interventional study - improved site-of-care decisions and tended to shorten length hospitalization. Inclusion of biomarker data in clinical algorithms improves individual decision-making in CAP patients. Interventional trials should be conducted to determine these markers' ultimate utility in patient management.