Adipophilin-stained lipid droplets and M2 macrophages in Jorge Lobo’s disease

Objectives: Jorge Lobo’s disease (JLd), a cutaneous mycosis caused by the fungus Paracoccidioides lobogeorgii, follows a chronic course and is refractory to any treatment modality. On histopathological view, the dermis presents crowded macrophages that have M2 polarization, which is associated with an anti-inflammatory profile and maintenance of the infection. Lipid droplets (LDs) are organelles responsible for neutral lipid storage for energetic needs. Intracellular pathogens may utilize LDs both to evade the immune response and as a source of nutrients. LDs in JLd have not yet been evaluated. Methods: This is an immunohistochemical study of 54 JLd skin samples using anti-adipophilin antibody for LDs analysis and anti-CD163 and anti-CD204 M2 macrophage markers. LDs were characterized as focal or diffuse, and their density was semi-quantitatively evaluated as absent or very scarce, mild, or strong. M2 macrophage density was obtained through the ImageJ software aid. Results: LDs were present within macrophages in 72.22% of cases, with high density in 53.85%, regardless of M2 macrophage density. Conclusions: Host-derived LDs may play a role in the pathogenesis of JLd.