Mediastinitis due to cryptococcal infection: a new clinical entity in the HAART era

Highly active antiretroviral therapy (HAART) produces a rapid decline in plasma HIV-1 RNA levels with concomitant immune reconstitution. Probably due to the enhanced immune function, shortly after starting HAART, some latent opportunistic infections precipitated. The aim of this study was to illustrate the results of a survey on Cryptococcus associated mediastinitis occurring after HAART introduction, carried out at a referral centre of Infectious Diseases in the north-east of Italy, between October 1999 and October 2000.

All consecutive HIV-positive patients, naive to HIV-protease inhibitor therapy, and diagnosed with culture-proven cryptococcal infection were included in the study. Clinical and immuno-virological parameters before HAART and subsequently for 12 months were evaluated.

Three of five patients were diagnosed with cryptococcal mediastinitis within a median time of 90 days (range, 60-150) after commencing HAART and fluconazole prophylaxis. Diagnosis was established by lymph node biopsy alone. Clinical improvement was documented when systemic anti-fungal therapy was combined with surgical drainage of the suppurative lesions. The role of immune restoration was confirmed by the significant increase in CD4 cell count, the reduction of HIV-RNA to undetectable levels and the prominent inflammatory reactions of lymph nodes.

Our report suggests that HIV-positive patients with prior cryptococcal systemic infection may present a re-exacerbation of atypical cryptococcosis as a manifestation of immune restoration, even when fluconazole prophylaxis is ongoing.