Relationship between disease severity and D-dimer levels measured with two different methods in pulmonary embolism patients

Pulmonary embolism (PE) is diagnosed with increasing frequency nowadays due to advances in the diagnostic methods and the increased awareness of the disease. There is a tendency to use non invasive diagnostic methods for all diseases. D-dimer is a fibrin degradation product. We aimed to detect the relationship between disease severity and the D-dimer levels measured with two different methods. We compared D-dimer levels in cases of massive vs. non-massive PE. A total of 89 patients who were diagnosed between 2006 and 2008 were included in the study. Group 1 included patients whose D-dimer levels were measured with the immunoturbidimetric polyclonal antibody method (D-dimerPLUS®), while Group 2 patients made use of the immunoturbidimetric monoclonal antibody method (InnovanceD-DIMER®). In each group, the D-dimer levels of those with massive and non-massive PE were compared, using the Mann Whitney U test. The mean age of Group 1 (25 F/26 M) was 56.0 ± 17.9 years, and that of Group 2 (22 F/16 M) was 52.9 ± 17.9 years. There was no statistical difference in gender and mean age between the two groups (p > 0.05). In Group 1, the mean D-dimer level of massive cases (n = 7) was 1444.9 ± 657.9 μg/L and that of nonmassive PE (n = 34) was 1304.7 ± 350.5 μg/L (p > 0.05). In Group 2, the mean D-dimer level of massive cases (n = 6) was 9.7 ± 2.2 mg/L and that of non-massive PE (n = 32) was 5.9 ± 1.3 mg/L (p < 0.05). The mean D-dimer levels of massive cases as measured with the immunoturbidimetric monoclonal antibody method were significantly higher. Pulmonary embolism patients whose D-dimer levels are higher (especially higher than 6.6 mg/L) should be considered as possibly having massive embolism. Diagnostic procedures and management can be planned according to this finding.