Acute lower respiratory tract infections (LRTIs) include community-acquired pneumonia (CAP), acute bronchitis, and acute exacerbation of chronic obstructive pulmonary disease (AECOPD). LRTIs are primarily caused by viral or bacterial pathogens.
It is reported that as many as 75% of patients with acute respiratory tract infections are treated with antibiotics even though the cause is mainly viral.1
Procalcitonin (PCT) is a host response biomarker that is sensitive and specific to bacterial infection.2 In patients with suspected or confirmed LRTI, PCT can help to differentiate bacterial infection from other potential causes and aid in decision-making around the initiation and duration of antibiotic therapy.
It is important to measure PCT levels at the first suspicion of infection to assess the likelihood of bacterial infection and need for antibiotic therapy. This will also help to determine severity of illness and risk for further progression of disease. Monitoring PCT levels helps to determine adequacy of source control and to early detect therapeutic failure.
Determine when it’s safe to discontinue antibiotics
Paired with clinical assessment, B·R·A·H·M·S PCT™ is the only FDA-cleared PCT and CE-certified assay to aid in decisions about initiating and/or discontinuing antibiotic therapy for patients with suspected or confirmed LRTI.5
PCT for differential diagnosis of LRTIs3,4
PCT < 0.10 ng/mL
Indicates absence of bacterial infection.*
The use of antibiotics strongly discouraged, also in the presence of imparted pulmonary reserve in AECOPD.
PCT > 0.10 - < 0.25 µg/L
Bacterial infection unlikely.*
The use of antibiotics is discouraged.
PCT > 0.25 - < 0.5 µg/L
Bacterial infection possible.*
Advice to initiate antimicrobial therapy.
PCT ≥ 0.5 µg/L
Suggestive of the presence of bacterial infection.*
Antimicrobial treatment strongly recommended.
Changes in PCT
Decline from peak
PCT > 80%
and clinical improvement
LRTI ≤ 0.25ng/mL
Sepsis ≤ 0.50ng/mL
PCT-supported therapy has been shown to reduce inpatient antibiotic exposure by 35% for LRTI patients without negative effects for mortality or length of stay.1,5-14
*PCT levels below 0.25 µg/L do not exclude an infection, because localized infections (without systemic signs) may also be associated with such low levels. In addition, if the PCT measurement is done very early after the systemic infection process has started (usually <6 hours), values may still be low. The PCT reference ranges are valuable guidelines for the clinician but they should always be interpreted in the context of the patient’s clinical condition. Antibiotic treatment should be started or continued on suspicion of infection, particularly in high-risk patients.
*PCT values may be elevated in certain conditions independent of bacterial infection. Decisions regarding antibiotic therapy should NOT be based solely on procalcitonin concentrations.23 Important considerations when interpreting PCT results.
PCT has been shown to reduce antibiotic prescription rates and duration in LRTI. In the multicentric, randomized controlled, interventional ProHosp trial (n=1359), antibiotic duration and antibiotic prescription rates were significantly reduced in the PCT group in comparison to the standard-of-care group for community-acquired pneumonia (CAP) (n=925), acute exacerbations of COPD (n=228), and bronchitis (n=151), resulting in an overall reduction of antibiotic exposure by 34.8% versus standard-of-care.1
Management of adults with hospital-acquired and ventilator-associated pneumonia: 2016 Clinical Practice Guidelines by the Infectious Diseases Society of America and the American Thoracic Society
In section XXIV: Should discontinuation of antibiotic therapy be based upon PCT levels plus clinical criteria or clinical criteria alone in patients with HAP/VAP?15
Recommendation: For patients with HAP/VAP, we suggest using PCT levels plus clinical criteria to guide the discontinuation of antibiotic therapy, rather than clinical criteria alone.15
The WHO recognizes that in vitro diagnostics (IVDs) are essential for advancing universal health coverage, addressing health emergencies, and promoting healthier populations, which are the three strategic priorities of the Thirteenth WHO General Programme of Work, 2019-2023.17
Recommendation: PCT to guide antibiotic therapy or discontinuation in sepsis and lower respiratory tract infection (for use only in tertiary care facilities and above)17
Recommendation: Assessment of PCT levels may be considered in patients with acute heart failure with suspected coexisting infection, particularly for the differential diagnosis of pneumonia and to guide antibiotic therapy, if considered.18,19