Academic journal article International Public Health Journal

The Overlapping and the Correlation between D-Dimer and C-Reactive Protein in Patients with Community-Acquired Pneumonia and Pulmonary Embolism

Academic journal article International Public Health Journal

The Overlapping and the Correlation between D-Dimer and C-Reactive Protein in Patients with Community-Acquired Pneumonia and Pulmonary Embolism

Article excerpt


In the process of having pneumonia, vascular congestion develops and the alveolar cavity fills with fibrin. Due to enzymatic degradation of this fibrin by the fibrinolytic system, fibrin degradation products can be released into the circulation. Alveolar fibrin deposition is the characteristic of diverse forms of acute lung injury. Intravascular thrombosis or disseminated intravascular coagulation can also occur in the acutely injured lung. Therefore, being one of the fibrin degradation products, D-dimer levels can be increased in pneumonia and pulmonary embolism (1,2). Pulmonary embolism (PE) is a disease that is relevant in all disciplines of medicine. Inadequate evaluation of risk factors and various nonspecific symptoms usually overlap or mimic pulmonary embolism to other diseases (3,4). Communityacquired pneumonia and PE show increased rise of CRP and D-dimer.

Community-acquired pneumonia (CAP) is also the sixth most common infectious cause of death in hospitals (5). The mortality rate in CAP outpatient cases is 1-5%; the mortality rate is 12% in inpatient cases and 40% in intensive care patients (6). Severity assessment is a crucial component in the management of patients presenting with CAP to guide physicians in clinical decisions, for both primary and secondary care physicians. Routine clinical judgments alone have been shown to be a poor predictor of disease severity (7). Existing severity tool (Pneumonia Severity Index) incorporates various combinations of co-morbidities, clinical and laboratory variables that are felt to be important in determining the clinical course of CAP (8).

CRP is an acute phase protein synthesized by the liver in response to tissue damage. CRP levels rise in any inflammatory condition, including bacterial, viral or fungal infections, rheumatoid syndromes, cancer, pregnancy and atherosclerotic disease. CRP is widely used in the management of CAP, including diagnosis, prognosis and follow-up. But its usefulness is not known (9). The mechanism by which CRP is raised in venous thromboembolism is not yet completely understood. It is suggested that its ability to induce tissue factor expression on monocytes plays an important role (10).

D -dimer results from the fibrin breakdown after fibrinolytic system activation by plasmin. Plasma Ddimer represents an endogen thrombolytic process. The potential use of plasma D-dimer levels has been assessed as a screening test for venous thromboembolism (11). It is a nonspecific test, influenced by many factors (patient's age, background illnesses, any inflammatory state, and pregnancy) (12). Its role in other disorders has not been defined as well.

Proinflammatory states in critically ill hospitalized patients lead to elevated D-dimer levels via cytokine activation of the coagulation cascade and corresponding inhibition of fibrinolysis (13). Elevated proinflammatory cytokines are associated with the severity of pneumonia (14). Some studies suggest that an increase in D dimer is directly related to the intraand extra-vascular coagulation that occurs in acute and chronic lung damage in CAP cases (15).

We have analyzed circulating inflammatory (CRP) and haemostatic (D-dimer) markers in patients with diagnosed pulmonary embolism and CAP. In patients with CAP, we have particularly analyzed the correlation of these parameters depending on the PSI score and survival. We hypothesized that there is a strong correlation between these two markers, and that it is particularly pronounced in patients with severe pneumonia, as their degree of inflammation and infection is greatest. High D-dimer value in CAP decreased differential diagnostic role of this parameter in PE, but indicates a high risk of mortality in CAP (16).


Our study included 37 patients with diagnosed pulmonary embolism in period from June 2010 to June 2012, and 108 patients with community-acquired pneumonia, diagnosed in the same period, at the Clinic for Lung Disease, Knez Selo, Clinical Center Nis, Serbia. …

Search by... Author
Show... All Results Primary Sources Peer-reviewed


An unknown error has occurred. Please click the button below to reload the page. If the problem persists, please try again in a little while.