The relationship between the concentration of PC and D-dimers in meningococcemia.

Plasma PC and D-dimers were measured at diagnosis in all patients who developed meningococcemia with or without multiorgan failure or purpura fulminans (groups I and II). D-dimers were measured by a semiquantitative latex agglutination assay, and the patients were separated into distinct groups on the basis of D-dimer values. The mean ± SD PC concentrations for patients with D-dimer values of less than 500 μg/mL, 500 to 1000 μg/mL, 1000 to 2000 μg/mL, 2000 to 4000 μg/mL, and more than 4000 μg/mL were 43.8 ± 14.35 IU/dL, 38.3 ± 9.5 IU/dL, 29.5 ± 9.7 IU/dL, 21.7 ± 3.3 IU/dL, and 17.76 ± 8.5 IU/dL, respectively. Although the concentration of PC was inversely proportional to the D-dimer values, patients with a normal D-dimer assay (< 500 μg/mL) still had significant reduction in PC. This suggests that consumptive coagulopathy is not solely responsible for acquired PC deficiency and that other mechanisms must also be involved.