Biomarkers in Pneumonia—Beyond Procalcitonin

Abstract

Pneumonia is the leading infectious cause of mortality worldwide and one of the most common lower respiratory tract infections that is contributing significantly to the burden of antibiotic consumption. Due to the complexity of its pathophysiology, it is widely accepted that clinical diagnosis and prognosis are inadequate for the accurate assessment of the severity of the disease. The most challenging task for a physician is the risk stratification of patients with community-acquired pneumonia. Herein, early diagnosis is essential in order to reduce hospitalization and mortality. Procalcitonin and C-reactive protein remain the most widely used biomarkers, while interleukin 6 has been of particular interest in the literature. However, none of them appear to be ideal, and the search for novel biomarkers that will most sufficiently predict the severity and treatment response in pneumonia has lately intensified. Although our insight has significantly increased over the last years, a translational approach with the application of genomics, metabolomics, microbiomics, and proteomics is required to better understand the disease. In this review, we discuss this rapidly evolving area and summarize the application of novel biomarkers that appear to be promising for the accurate diagnosis and risk stratification of pneumonia.

Procalcitonin and C-reactive Protein Perform Better Than Neutrophil-Lymphocyte Count Ratio on Evaluation of Hospital Acquired Pneumonia

“…Over the past few years, numerous researches have investigated the clinical value of various biomarkers in diagnosis, prognosis and stratification of pneumonia [25]. Many studies have focused on the significance of single biomarkers, meanwhile interests in multiple biomarkers have increased, especially in severity evaluation of infective conditions, such as sepsis, septic shock and CAP.…”

Biomarkers of Infection and Inflammation

“…Pneumonia is one of the most common lower respiratory tract infections and is a leading cause of mortality worldwide. [67][68][69] For bacterial pneumonia, timely antibiotic treatment is important for prognosis. The ideal biomarker for bacterial pneumonia should either indicate inflammation or is released from the lung due to infection.…”

“…The ideal biomarker for bacterial pneumonia should either indicate inflammation or is released from the lung due to infection. 67 The most widely used biomarkers for diagnosis and prognosis of bacterial pneumonia include CRP and PCT, although both can be elevated in other bacterial infections and conditions. 67,68 PCT is often used to guide the initiation and duration of antibiotic treatment.…”

“…67 The most widely used biomarkers for diagnosis and prognosis of bacterial pneumonia include CRP and PCT, although both can be elevated in other bacterial infections and conditions. 67,68 PCT is often used to guide the initiation and duration of antibiotic treatment. 70 Novel biomarkers for pneumonia are continually sought with several studies investigating the potential of interleukin-6 (IL-6), a cytokine in the acute phase response that is elevated in patients with pneumonia.…”

“…70 Novel biomarkers for pneumonia are continually sought with several studies investigating the potential of interleukin-6 (IL-6), a cytokine in the acute phase response that is elevated in patients with pneumonia. 67,[71][72][73] Invasive fungal infections are of worldwide importance due to an increasing immunosuppressed population and increasing numbers of transplant recipients. 74 For more than two decades research has been ongoing for two fungal biomarkers, galactomannan (GM) and 1,3-β-D-glucan (BDG).…”