Cryptococcemia. A 44- necropsies cases study of AIDS- patients in a tertiary care hospital

Clóvis Klock^*, Luciano Z. Goldani^**, Marcelle Cerski^**, Ivan Tadeu Rebouças^*
* URI - CAMPUS DE ERECHIM BRASIL
** HCPA - UFRGS BRASIL

Resumen

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Introduccion    

Cryptococcosis is a systemic mycosis caused by an encapsulated and yeast form fungus called Cryptococcus neoformans.
Most of the time, it infects individuals with some immunodeficiency and it is considered an opportunistic mycosis. Cryptococcosis was described for the first time in 1894 by the pathologist Busse and the surgeon Buschke. The first case of neurocryptococcosis was described in 1905 by Van Hanseman in a man with meningitis.

Cryptococcus neoformans has five subtypes (A,B,C,D and AD), and  three varieties: grubbi (A serotype), neoformans (D serotype) and gatii (B and C serotypes). The grubbi variety is present worldwide. The gatti variety is found more frequently in tropical and subtropical regions and the neoformans has a major prevalence in Europe and South America. Recently molecular biology PCR-based studies have isolated eight major molecular types classificated as: VNI (grubbi variety, A serotype), VNII (grubii variety, A serotype), VNIII (AD serotype), VNIV (neoformans variety, D serotype), VGI, VGII, VGIII, VGIV (gatti varieties, B and C serotypes). No correlation between the serological and molecular types in the gatti variety was found.

In its anamorphous form, the Cryptococcus neoformans is an encapsulated yeast (with non- encapsulated and capsule-deficient forms), measuring between 5  to 10 um diameter. The capsule is clearly a virulence factor of the fungus. In experimental cryptococcosis,  mutant or non - encapsulated fungi are less virulent than the encapsulated species. A number of effects of the capsule can contribute with the virulence and it can inhibit the phagocytosis of macrophages, monocytes and neutrophils. The pathogenesis of cryptococcosis is determined by three factors: the system of defense of the host, the virulence of the type of Cryptococcus neoformans and the size of the entry site. The role of these three factors is not clearly interrelated, but certainly its relation is hugely complex.

Material y Métodos    

Resultados    

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Cryptococcus (Alcian Blue Stain) -

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Cryptococcus - Liver -

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Cryptococcus - Spleen - Alcian-Blue stain -

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Cryptococcus - Meningis -

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Cryptococcus - Brain -

Discusión    

Cryptococcosis is a leading mycological cause of morbidity and mortality among patients with AIDS. About 10 % of AIDS patients develop cryptococcosis in the United States, Europe and Australia, whereas its incidence is much higher in countries of sub-Saharan Africa (15–30 %). It is estimated that 10–25 % of AIDS patients with cryptococcosis die in spite of antifungal therapy, and 30–60 % succumb within the first year of onset.

The disease is acquired by inhalation of the fungus whose dehydrated spores penetrate throughout the airways, and the initial implantation sites are the lungs. Once in lung parenchyma, the fungus rehydrate and acquire the polysaccharide compositions of the gel capsule, today known as the most important factor of the disease pathogenesis. A primary lesion is established in the lung, with secondary involvement of hilar lymph nodes, constituting a primary complex, similar to tuberculosis and histoplasmosis. The initial lung lesion has a systemic haematogenic spreading potential to several organs, or reactivation potential in immunodepressed patients. In alveolar spaces, the fungic cells are initially taken on by the alveolar macrophages and the infection will depend upon the interaction between the host defense system and the fungus type virulence. The first interaction between the fungus and the alveolar macrophage can determine if the disease is going progress or not.

The Central nervous system is the most important target in cryptococcosis, although the cerebral lesion is always secondary to a lung foci, which is an entry site of this mycosis and  many times can regress or even disappear before the onset of the neurological symptoms.

Conclusiones    

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Bibliografía    

1 – Nobre V, Braga E, et al Opportunistic infections in patients with aids admitted to an universityhospital of the Southeast of Brazil. Rev Inst Med Trop Sao Paulo. 2003. 45(2):69-74

2 - Viriyavejakul P, Rojanasunan P, et al.Necropsy in HIV-infected patients.

Southeast Asian J Trop Med Public Health. 2002. ;33(1):85-91. 

3 - Tietz HJ, Martin H, Koch S. Incidence of endomycoses in autopsy material. Mycoses. 2001.44(11-12):450-4. 

4 – Perfect JR, Casadevall A. Cryptococcosis. Infect Dis N Am, 16:837-874, 2002.

5 –  Lee  SC, Dickson DW, Casadevall A. Pathology of Cryptococcal Meningoencephalites: Analysis of 27 patients with pathogenetic implications. Human Pathology, 27(8):839-847, 1996.

Comentarios

- Emilio Mayayo Artal (03/10/2005 0:31:34)

Buen trabajo y buena estadística. Enhorabuena. Emilio

- Mirta Garcia Jardon (12/10/2005 17:41:40)

Congratulations for the nice presentation of your paper. The images are very representative and the number of cases rather high. I thought the number of patients with AIDS with secondary cryptoccocal infection would be higher though. Probably you excluded those ones with only localized infection by Cryptoccocus. Am I right?

- Oscar Marin (17/10/2005 2:52:35)

Good work with notoriuos high rate of spleen localization of this fungus.

- Clóvis Klock (24/10/2005 20:23:15)

Dr. Jordon:
Gracias por su interese. Los casos apresentados solamiente son de casos com dos ou mas organos com Cryptococcus. Los casos com uno organo somiente no estão en traballo. Saludos

- Clóvis Klock (24/10/2005 20:24:03)

Dr. Marin:
Gacias por su comentario.
Saludos

- Mirta Garcia Jardon (31/10/2005 17:06:56)

Thanks very much for answering me back, Dr. Klock. Congratulations once again.