Table 1 Overview of studies investigating the use of procalcitonin in different types and sites of infections

Pulmonary

AECOPD

yes

RCT (N = 120),

meta-analysis

<0.25

++

PCT reduces initiation of antibiotic treatment in the ED without adverse outcomes

[7, 12]

Asthma

yes

RCT (N = 216)

<0.1–0.25

++

PCT reduces initiation of antibiotic treatment in the ED without adverse outcomes

[89]

Bronchitis

yes (Registry)

RCT, real-life (Registry)

<0.1–0.25

++

PCT reduces initiation of antibiotic treatment in the ED without adverse outcomes

[42]

Community-acquired pneumonia

yes

RCT, meta-analysis (N = 4467)

real-life (Registry)

<0.1–0.25; 80–90% decrease

+++

PCT shortens length of antibiotic therapy in the ED and hospital ward without adverse outcomes

[7]

Pulmonary fibrosis

yes

RCT (N = 78)

<0.25

++

PCT reduces initiation of antibiotic treatment in the ED without adverse outcomes

[15]

Upper respiratory tract infections

no

RCT (N = 458, 702)

<0.1–0.25

+++

PCT reduces initiation of antibiotic treatment in primary care without adverse outcomes (non-inferiority)

[90, 91]

Heart

Congestive heart failure

yes

Observational, RCT (secondary analysis, N = 110)

<0.21–0.25

++

PCT helps in identification of bacterial superinfection in acute heart failure, may be helpful in guiding antibiotic treatment

[38, 43]

Endocarditis

no

Observational, meta-analysis

<0.5

+

PCT is a predictor of poor outcome, diagnostic value similar to CRP

[67, 68]

Abdominal

Abdominal infections with peritonitis

yes

Observational

<0.5; 80% decrease

++

PCT-guided therapy was associated with lower antibiotic exposure with no difference in mortality

[66]

Appendicitis

yes

Observational, meta-analysis

NR

+

PCT is a marker of complicated appendicitis, low value for diagnosing appendicitis

[92]

Pancreatitis

yes

RCT (N = 71)

<0.5

++

PCT reduces antibiotic exposure compared to prophylactic antibiotic treatment without adverse outcomes

[65]

Urinary tract infections

yes

RCT (N = 125)

<0.25

++

PCT reduces antibiotic exposure without adverse effects

[47]

Blood

Blood stream infection

yes

Observational

<0.25–1.47

++

PCT levels correlate with risk for positive blood cultures

[19, 27]

Neutropenia

yes

RCT (N = 62)

NR

–

PCT is not useful to manage antibiotic therapy, but PCT was a marker of bacteremia

[93]

Severe sepsis/shock

yes

RCT (N = 1575)

<0.5; 80% decrease

+++

PCT reduces antibiotic exposure and 3 month mortality in the ICU

[30]

Postoperative

Postoperative abdominal infection

yes

Observational, meta-analysis

NR

+

Low PCT post-surgical ensure safe discharge, PCT is similar to CRP

[58, 59]

Postoperative infections

yes

RCTs, Observational

<0.5–2.0

++

Low PCT suggests absence of perioperative infection and enables early discharge

Other

Arthritis

yes

Observational

<0.5

+

PCT identifies infection in patients with rheumatoid arthritis

[94]

Erysipelas

yes

Observational

<0.1

+

PCT differentiates erysipelas from DVT

[81]

Meningitis

no

RCT, meta-analysis (N = 2058)

<0.5

+++

PCT reduces AB treatment during viral outbreak; serum PCT with CSF lactate reliably identifies bacterial meningitis

[72, 74]