Diagnostic Accuracy of Infection Biomarkers in the Initial Investigation of Patients With Suspected Pneumonia
Diagnostic Accuracy of Infection Biomarkers in the Initial Investigation of Patients With Suspected Pneumonia
The aim of this study is to investigate the diagnostic and prognostic value of C-reactive
 protein (CRP), serum procalcitonin (PCT) and soluble urokinase plasminogen activator receptor
 (suPAR) in the initial investigation of patients acute hospitalized with suspected
 community-acquired-pneumonia (CAP)
Target pneumonia treatment should be initiated within a few hours, which is why early and
 accurate diagnosis is extremely important. Uncertain or delayed diagnosis will often lead to
 an overconsumption of broad-spectrum antibiotics, which contributes to increased development
 of resistant bacteria and thus threaten the treatment options of the future. Pneumonia
 diagnosis is primarily made today on the basis of clinical symptoms and findings in the form
 of cough, vomiting, chest pain, fever, shortness of breath, supplemented with X-ray of the
 lungs, relevant blood tests and analysis of expectoration. However, X-ray is an imprecise
 diagnostic tool. The diagnosis of CAP is challenged by nonspecific symptoms, uncertain
 diagnostic methods and waiting time for test results up to several days.

 Therefore, numerous studies have investigated biomarkers that can possibly support the
 diagnosis of CAP. C-reactive protein (CRP) and serum procalcitonin (PCT) are biomarkers that
 may distinguish CAP from other causes of acute respiratory infections. The CRP biomarker has
 been endorsed as a guide for antibiotic treatment by the National Institute for Health and
 Care Excellence (NICE) and PCT was suggested by the American Infectious Diseases Society of
 America. Soluble urokinase plasminogen activator receptor (suPAR) has emerged as a
 potentially novel biomarker for inflammatory diseases including pneumonia. Several studies
 have highlighted suPAR as a significant prognostic mortality marker and strongly related to
 disease severity and worse outcome in a variety of conditions. It is also a promising
 biological marker in the diagnosis of CAP.

 The diagnostic value of the optimal biomarkers for the diagnosis of CAP remains
 controversial. The investigators hypothesize that serum CRP, PTC and suPAR have an impact on
 diagnosing, prognosis, and treatment of patients with a verified
 community-acquired-pneumonia. The objectives of the study are:

 -  To identify the diagnostic accuracy of CRP, PCT and suPAR in community-acquired
 pneumonia

 -  To identify the prognostic value of CRP, PCT and suPAR in relation to adverse events
Inclusion Criteria:

 -  Adult patients ≥ 18 years old

 -  Patients suspected with pneumonia by the attending physician. The physician will base
 his/her suspicion on e.g. clinical symptoms such as cough, increased sputum
 production, chest tightness, dyspnea and fever > 38⁰C, and indication for chest x-ray

 Exclusion Criteria:

 -  If the attending physician considers that participation will delay a life-saving
 treatment or patient needs direct transfer to the intensive care unit.

 -  Admission within the last 14 days

 -  Verified COVID-19 disease within 14 days before admission

 -  Pregnant women

 -  Severe immunodeficiencies: Primary immunodeficiencies and secondary immunodeficiencies
 (HIV positive CD4 <200, Patients receiving immunosuppressive treatment (ATC L04A),
 Corticosteroid treatment (>20 mg/day prednisone or equivalent for >14 days within the
 last 30 days), Chemotherapy within 30 days)