Description
Use: Aid in establishing the presence if Cryptococcus neoformans infection
Limitations: Nonspecific agglutination may be caused by the presence of rheumatoid factor. The LA test is known to cross-react with Trichosporon sp.
Additional Information: The cryptococcal antigen test is positive in about 85% to 90% of cryptococcal meningitis. Its sensitivity reaches 95% in patients with AIDS.
Cryptococcosis is an invasive fungal infection caused by Cryptococcus neoformans. The organism has been isolated from several sites in nature, particularly weathered pigeon droppings.
Infection is usually acquired via the pulmonary route. Patients are often unaware of any exposure history. Approximately half of the patients with symptomatic disease have a predisposing immunosuppressive condition such as AIDS, steroid therapy, lymphoma, or sarcoidosis. Symptoms may include fever, headache, dizziness, ataxia, somnolence, and cough.
In addition to the lungs, cryptococcal infections frequently involve the central nervous system (CNS), particularly in patients infected with HIV. Mortality in CNS cryptococcosis may approach 25% despite antibiotic therapy. Untreated CNS cryptococcosis is invariably fatal. Disseminated disease may affect any organ system and usually occurs in immunosuppressed individuals.