Patients with active infection with Paracoccidioides brasiliensis present a Th2 immune response characterized by high Interleukin-4 and Interleukin-5 production.

Paracoccidiodomycosis (PCM) is caused by the dimorphic fungus Paracoccidioides brasiliensis. In humans, the disease presents a broad spectrum of clinical manifestations, ranging from localized mucocutaneous lesions to a widespread manifestation with involving the mononuclear phagocyte system. In attempt to better understand the regulation of immune response during the infection, this study analyzed the production of regulatory and inflammatory cytokines in 25 infected patients and 19 health controls. Regulatory and inflammatory cytokines were analyzed in supernatants of peripheral blood mononuclear cells (PBMC) stimulated with mitogens or soluble P. brasiliensis antigens. A pattern of Th2 immune response was observed in patients, mainly attributed to a higher production of IL-4 and IL-5 than to a lower production of IFN-gamma. Patients with disseminated infection presented undetectable levels of IFN-gamma after antigen stimulation and high levels of IL-1beta, which were probably associated with the inflammatory reaction observed in multifocal infection.