Weil's disease with elevated plasma D-dimer.

We report a case of Weil's disease manifesting elevation of plasma D-dimer in the acute phase. Later, in the convalescent phase after treatment, the plasma levels of D-dimer returned to normal. Plasma D-dimer can be used as a marker of fibrin formation and degradation. Based on our observations, we conjecture that fibrin formation and fibrinolysis may occur in the acute phase of Weil's disease.