title: IsCryptococcus gattiia Primary Pathogen?
abstract: The two etiologic agents of cryptococcal meningoencephalitis,Cryptococcus neoformansandC. gattii, have been commonly designated as either an opportunistic pathogen for the first species or as a primary pathogen for the second species. Such a distinction has been based on epidemiological findings that the majority of patients presenting meningoencephalitis caused byC. neoformansare immunocompromised whileC. gattiiinfection has been reported more often in immunocompetent patients. A recent report, however, showed that GM-CSF (granulocyte-macrophage colony-stimulating factor) neutralizing antibodies were prevalent in the plasma of "apparently immunocompetent"C. gattiipatients with meningoencephalitis. Because GM-CSF is essential for differentiation of monocytes to macrophages and modulating the immune response, it is not surprising that the lack of GM-CSF function predisposes otherwise healthy individuals to infection via inhalation of environmental pathogens such asC. gattii. Since the test for anti-GM-CSF autoantibodies is not included in routine immunological profiling at most hospitals, healthy patients with GM-CSF neutralizing antibodies are usually categorized as immunocompetent. It is likely that a comprehensive immunological evaluation of patients withC. gattiimeningoencephalitis, who had been diagnosed as immunocompetent, would reveal a majority of them had hidden immune dysfunction. This paper reviews the relationship between GM-CSF neutralizing antibodies and the risk forC. gattiiinfection with CNS involvement.
authors: Molecular Microbiology Section, Laboratory of Clinical Infectious Diseases, National Institutes of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA.
authors: Kyung J
authors: KJ
authors: Kwon-Chung
authors: Second Department of Internal Medicine, Nagasaki University Hospital, Sakamoto 1-7-1, Nagasaki-city, 851-8501, Japan.
authors: Tomomi
authors: T
authors: Saijo
keywords: Cryptococcosis; Cryptococcus gattii; anti-GM-CSF autoantibodies; immune dysfunction