Paradoxical increase in circulating Aspergillus antigen during treatment with caspofungin in a patient with pulmonary aspergillosis

A paradoxical increase in circulating Aspergillus antigen was observed during treatment with caspofungin in a patient with proven invasive aspergillosis. With the exception of treatment with the echinocandin, no other factors were found that might explain this clinical observation, which was supported by experiments done in vitro.