Cryptococcosis in apparently immunocompetent patients.
BACKGROUND
Few reports have described the clinical and microbiological features of cryptococcosis in immunocompetent patients.


OBJECTIVE
To compare clinical presentations and outcomes of cryptococcosis in immunocompetent vs. immunocompromised patients.


METHODS
Retrospective case series.


METHODS
All culture- or histology-confirmed cases (n = 46) of cryptococcosis in two acute hospitals in Hong Kong (1995-2005) were included. Clinical presentations, rates of fungaemia, cerebrospinal fluid (CSF) parameters and clinical outcomes were recorded.


RESULTS
Twenty patients (43.5%) were apparently immunocompetent, 17 (37.0%) had predisposing factors other than HIV infection, and 9 (19.6%) were HIV-positive. Thirty-one (67.4%) presented with meningitis, four (8.7%) with pulmonary cryptococcosis, and 11 (23.9%) with extraneural, extrapulmonary cryptococcosis. Of the immunocompetent patients with retrievable isolates (n = 8), three (37.5%) were Cryptococcus gattii; all isolates (n = 6) from immunocompromised patients were Cryptococcus neoformans var. grubii. Immunocompetent patients more commonly presented with meningitis (80.0% vs. 47.1%, p = 0.03), and tended toward lower rates of fungaemia (10.0% vs. 35.3%, p = 0.06) and mortality (25.0% vs. 52.9%, p = 0.06). Death was associated with fungaemia (p = 0.01) and underlying malignancy (p < 0.01). In cryptococcal meningitis, immunocompetent patients had longer mean time from illness onset to presentation (34.4 vs. 12.6 days, p = 0.02), more intense inflammatory responses (CSF: white blood cells 108 vs. 35 x 10(9)/l, p = 0.03; protein 1.61 g/l vs. 0.79 g/l, p = 0.07), less fungaemia (0% vs. 26.7%, p = 0.04) and more satisfactory clinical outcomes (81.3% vs. 46.7%, p = 0.04).


CONCLUSIONS
A substantial proportion of patients with cryptococcosis are apparently immunocompetent. C. neoformans var. grubii and C. gattii are the common causes. Immunocompetent patients tend to present with localized, indolent neurological disease, with more intense inflammatory responses but better clinical outcomes.
Lui
G
G
Division of Infectious Diseases, Department of Medicine and Therapeutics, 9/F Clinical Sciences Building, Prince of Wales Hospital, Hong Kong.
Lee
N
N
Ip
M
M
Choi
K W
KW
Tso
Y K
YK
Lam
E
E
Chau
S
S
Lai
R
R
Cockram
C S
CS
D000328:Adult; D000368:Aged; D003453:Cryptococcosis / Q000453:epidemiology / Q000276:immunology* / Q000382:microbiology; D003454:Cryptococcus / Q000145:classification; D005260:Female; D006723:Hong Kong / Q000453:epidemiology; D006801:Humans; D007121:Immunocompetence / Q000276:immunology*; D016867:Immunocompromised Host; D008297:Male; D008875:Middle Aged; D012150:Polymorphism, Restriction Fragment Length; D012189:Retrospective Studies; D012307:Risk Factors