Breakthrough cryptococcosis in a patient with systemic lupus erythematosus (SLE) receiving micafungin

A 67-year-old woman with systemic lupus erythematosus (SLE) was admitted to our hospital because of lupus nephritis. Methylprednisolone minipulse therapy dramatically reduced her proteinuria; however; she then complained of general fatigue with low-grade fever. Radiological and culture studies revealed no infectious focus, but she was treated with meropenem and micafungin, considering her immunosuppressive state. Cytomegalovirus antigenemia was later determined and ganciclovir was added. She became afebrile, but complained of nausea and headache, and disorientation, without meningeal signs. Because a brain computed tomography (CT) scan showed no abnormality, we initially suspected some kind of drug interaction. Despite the discontinuation of all drugs, however, she still suffered from disturbance of consciousness. A lumbar puncture revealed yeast cells stained by India ink. A diagnosis of cryptococcal meningitis was confirmed. Though fluconazole and meropenem were administered, the patient died. Autopsy findings revealed disseminated cryptococcosis concomitant with pulmonary aspergillosis. Micafungin is a recently approved echinocandin-class antifungal agent that is now widely used in Japan because of its minimal toxicity and broadspectrum activity. However, such echinocandins have limited activity against a number of fungi. Indeed, breakthrough trichosporonosis is becoming a significant problem in patients with hematological malignancies who are receiving echinocandins. To the best of our knowledge, breakthrough cryptococcosis, as seen in our patient, has not been reported previously in patients who were receiving micafungin as an empiric antifungal therapy. This case highlights that cryptococcosis should be kept in mind as a possible breakthrough infection during the administration of echinocandins, especially in patients with cellular immunodeficiency.