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In paracoccidioidomycosis (PCM), the primary lung infection remains silent. In this study, attempts were done to define the primary target organ by correlating lung radiographic abnormalities with the time course of mucosal/skin lesions concurrently exhibited at diagnosis by 63 patients in whom microscopy and/or isolation of Paracoccidioides brasiliensis from respiratory secretions had been positive. Mucosal and skin lesions were found in 65.1% and 12.7% of the patients, respectively. Odynophagia and dysphagia were present in 38.1% each. All patients had lung interstitial infiltrates, and 31.7% had also alveolar lesions; fibrosis was recorded in 46% of them. An inverse correlation was shown for fibrosis and presence of either odynophagia or dysphagia. Cluster analyzes strongly supported two sets of patients: those with mucosal damage, odynophagia/dysphagia, and alveolo-interstitial infiltrates and those with dermal lesions, dyspnea, and lung fibrosis. These groups may represent novel stages in the natural course of PCM.

It is known that peritoneal murine macrophages activated with interferon-gamma exert a fungicidal effect against Paracoccidioides brasiliensis conidia by a nitric oxide (NO)-mediated mechanism. This NO-mediated effect can also be induced by other cytokines such as tumor necrosis factor-alpha (TNF-alpha). The aim of this study was to determine if TNF-alpha-activated peritoneal murine macrophages infected with P. brasiliensis were able to show fungistatic/fungicidal effects mediated by NO. The results indicated that although macrophage activation with TNF-alpha did not result in NO production, these cells played an important role in inhibiting the conidia from becoming yeast cells. In vivo, the NO-independent inhibitory effect would prove of importance for the establishment of P. brasiliensis in host tissues.