Elevated Plasma D-Dimer in Adult Community-Acquired Pneumonia Patients is Associated with an Increased Inflammatory Reaction and Lower Survival

BACKGROUND: Community-acquired pneumonia (CAP) is a common infectious disease. Inflammatory reaction and prognosis assessment in adult CAP patients are useful for CAP site of care decisions. Most CAP patients were diagnosed in an out-patient or emergency department, so a simple, cheap and rapidly available measurement to assess inflammatory reaction and prognosis has the prospect of broad application. The aim of this study was to investigate the usefulness of plasma D-Dimer in assessment of inflammatory reaction and prognosis in adult CAP patients. METHODS: A retrospective study was conducted. All adult patients with a primary diagnosis of CAP were included and were evaluated by peripheral plasma D-Dimer test. All of the measurement data were analyzed with paired t-test and the enumeration data were analyzed with χ2 test. Correlative factor analysis was performed between D-Dimer levels and serum inflammatory markers (WBC, hs-CRP, PCT) and prognostic indexes (ICU admission and 30-day mortality). Receiver operating characteristic curves (ROC) were used to evaluate the sensitivity and specificity of D-Dimer in predicting ICU admission and/or 30-day mortality. RESULTS: One hundred fifty patients were included. Compared with non-D-Dimer elevated group, serum inflammatory markers (WBC, hs-CRP, PCT) and prognostic indexes (ICU admission and 30-day mortality) were elevated in the D-Dimer elevated group (p < 0.05). D-Dimer had positive correlation with serum inflammatory markers (WBC, hs-CRP, PCT), the rates of ICU admission and 30-day mortality, and scores of CURB-65. The AUC of ROC curve of D-Dimer was 0.880 (95% CI 0.823 to 0.936), the sensitivity was 80.4% and specificity was 79.8%, D-Dimer levels are superior to hs-CRP and PCT in predicting 30-day mortality and/or ICU admission according to AUCs of the ROC curves. CONCLUSIONS: Elevated plasma D-Dimer in adult CAP patients is associated with an increased inflammatory reaction and ICU admission and 30-day mortality. It can be a simple, cheap, and rapidly available measurement to assess inflammatory reaction and prognosis in adult CAP patients.