[Cryptococcus neoformans infection in hematologic malignancies]

Fungal CNS infections in patients with hematologic malignancy

Various fungal agents can cause CNS infections. CNS fungal infections may present as a mass (i.e., brain abscess) typically in the course of aspergillosis or zygomycosis, or may primarily involve the meninges (i.e., meningitis), as can be observed in patients with candidiasis or cryptococcosis. Most commonly, fungal brain abscesses are due to aspergillosis. CNS aspergillosis is observed particularly in acute leukemia and allogeneic hemopoietic stem cell transplantation patients. Usually, aspergillosis is localized in the lungs and secondarily spreads to the brain; only in few cases does it develop as solitary localization of CNS. In these conditions, diagnosis is very difficult because signs and symptoms can be completely aspecific. Diagnosis can often be performed only through aggressive procedures (i.e., stereotactic puncture). Zygomycetes are the second most frequent cause of brain abscesses. CNS involvement is higher than in the course of invasive aspergillosis, and this fungal complication is also characterized by a high mortality rate. In vitro and in vivo studies demonstrated that only posaconazole and lipid formulations of amphotericin B present some possibility of success in the treatment of zygomycosis, but the pharmacologic approach should always be associated with surgery. Among molds, other agents (i.e., Fusarium and Scedosporium) may also be responsible for fungal abscess. More rarely during the course of a hematologic malignancy, a meningeal candidiasis or cryptococcosis may be observed. This review mainly focuses on the epidemiology, clinical manifestations, diagnosis and management strategies of all cases of CNS fungal infections in hematologic patients.

Invasive aspergillosis in the hematologic and immunologic patient: new findings and key questions in leukemia

Patients suffering from acute leukemia are at high risk for invasive aspergillosis and a large review and a recent clinical trial have shown that they represent the largest group of patients developing the disease. New host groups such as patients with multiple myeloma or low-grade lymphoproliferative disorders have contributed to an increase in the incidence of invasive aspergillosis over recent years. There are substantial differences in the diagnostic strategy and therapeutic outcome of disease between patients with a hematological malignancy and other host groups such as allogeneic hematopoietic stem cell transplant patients. Galactomannan detection ELISA test is more specific in adult patients with hematological malignancies than in hematopoietic stem cell transplantation recipients. As a result of possible improvement of the underlying immune deficiency upon recovery from neutropenia, survival is higher in leukemic patients with invasive aspergillosis than in other host groups. However, there is currently no evidence of an effective antifungal prophylaxis strategy against aspergillosis in leukemic patients. As these patients account for a majority of the aspergillosis cases, clinical trials on prophylaxis should not only be focused on allogeneic stem transplant recipients but also be designed for the patient with leukemia.