[Cryptococcus neoformans meningoencephalitis among apparently immunocompetent patients: description of two cases]

Cryptococcus neoformans is a ubiquitous fungal pathogen which causes human disease ranging from asymptomatic colonization of the lungs, to severe pneumonia, mediastinitis, meningitis or generalized infection. Although cryptococcal infection shows notably opportunistic features, it is sometimes also found among apparently immunocompetent individuals, with an extremely adverse outcome in the case of SNC involvement. Therefore, when faced with a presumed healthy person with anamnestic, clinical, CSF and instrumental findings consistent with chronic meningitis/meningoencephalitis, we must also consider cryptococcosis as a possible cause of disease. This may be rapidly achieved by resorting to quite a simple serological test, namely cryptococcal antigen detection. We describe two cases of cryptococcal meningoencephalitis occurring among apparently immunocompetent subjects (both HIV-negative, not under corticosteroid or immunosuppressive regimen, nor undergoing chemotherapy or radiotherapy. Laboratory diagnostics revealed the existence of reasonable immunological deficit for both subjects. Unfortunately, we were unable to establish whether the alterations in question were preexisting or concomitant with fungal infection. Our patients' course was somewhat problematic, according to findings observed in broader-based studies: this could mostly be explained by the considerable diagnostic delay which often marks cryptococcal infections of immunocompetent individuals. Nevertheless, neither of these two cases were complicated by intracranial pressure increase, leading us to speculate whether this disease may occur less frequently under conditions of substantial immunological integrity.