Study of murine experimental Jorge Lobo's disease by analysis of peritoneal lavage cells and footpad histopathology: early versus chronic lesions

The murine model of Jorge Lobo's disease is characterized by histological alterations similar to those seen in human disease, including a large number of viable fungi. This study evaluated the immune response of mice with early and late macroscopic lesions (5 and 13 months post-inoculation [p.i.], respectively) by the analysis of peritoneal lavage cells and footpad (FP) histology. The FP of mice were inoculated with 1 × 10(6) fungi (viability index of 41%). At 5 and 13 months p.i., the granuloma mainly consisted of macrophages and multinucleated giant cells, but a larger number of neutrophils was observed at 5 months and lymphocytes at 13 months. The number of fungi in the FP and fungal viability were 1.8 ± 1.1 × 10(6) fungi/ml and 38.5% at 5 months p.i. and 30.8 ± 11.7 × 10(6) fungi/ml and 9% at 13 months (P < .05). Higher production of H₂O₂, O₂(-), IL-10, and TNF-α were observed at 13 months (P < .05), but there was no significant difference in the production of NO, IL-2, IL-4, IL-12 and IFN-γ. The results showed significant differences between early and late lesions and support the use of BALB/c mice for evaluation of the different phases of infection.