Lagochilascaris minor: Susceptibility and Resistance to Experimental Infection in Mice Is Independent of H-2 Haplotype and Correlates with the Immune Response in Immunized Animals

A Case of Lagochilascariasis in Suriname with the Involvement of the ENT System and the Skull Base

We describe a case of human lagochilascariasis, with skull-base involvement and a chronic and relapsing course after treatment. This rare parasitic infection is usually manifested in the head and neck area, characterized by progressive granulomatous inflammation and the formation of abscesses. Transmission to humans most likely occurs by the consumption of undercooked meat of wild rodents. On the basis of literature studies, we propose the most likely life cycle of the parasite that involves wild feline and rodent species, with humans as accidental hosts. Even in endemic areas, it is very difficult to recognize the disease at an early stage. Progression will eventually lead to involvement of the (central) nervous system, as described in our case. Treatment is often difficult and involves resection and prolonged treatment with anthelmintic drugs. Recurrences are not uncommon and at present, long-term oral administration of ivermectin seems to be the most effective treatment.

Analysis of Spleen Cells in Susceptible and Resistant Mice with Experimental Lagochilascariosis

Lagochilascariosis is an emerging parasitic disease caused by the helminth Lagochilascaris minor. The experimental mouse model has been used to study the immune response against L. minor infection. In the present work, immunohistochemistry analysis of spleen cells populations was evaluated in susceptible (C57BL/6) and resistant (BALB/c) mice experimentally infected with L. minor. The BALB/c mice exhibited increased spleen cell indexes as follows: F4/80+ at 100 days after infection (DPI), CD4+ at 100 and 250 DPI, CD8+ at 35 and 100 DPI, and CD19+ at 100, 150, and 250 DPI. In the spleens of the infected C57BL/6 mice, increased indexes of the following spleen cells were observed: F4/80+ cells at 250 DPI, CD4+ cells at 150 DPI, CD8+ cells at 35, 150, and 250 DPI, and CD19+ cells at 150 to 250 DPI. The index of spleen cells confirmed the differences between the control and infected groups at several time points following the infection. These data demonstrate an association between a preferential increase in the number of CD4+ and CD19+ spleen cells and resistance to experimental lagochilascariosis in BALB/c mice and between a preferential increase in the number of CD8+ spleen cells and susceptibility in C57BL/6 mice.

Strain variation in the susceptibility and immune response to Clonorchis sinensis infection in mice

Mice have shown various susceptibility to infection by Clonorchis sinensis. To compare the intra-specific variation in the host-parasite relationship of C. sinensis, 6 strains of mice (ICR, BALB/c, C57BL/6, DDY, CBA/N, and C3H/HeN) with 3 different haplotypes were evaluated on their susceptibility. The worm recovery rate and immunological responses were observed after 4 and 8 weeks of infection with 30 metacercariae. The highest worm recovery rate was observed as 20.7% in the C3H/HeN strain after 4 weeks of infection along with histopathological changes. The rate was 10.0% in C57BL/6 mice after 8 weeks. ICR, BALB/c, and CBA/N showed elevated levels of IgE at both time points when compared to the rest of the strains. The serum IgG1 and IgG2a levels were elevated in most of the strains; however, the C57BL/6 strain showed a lower level of IgG2a that indicated the IgG1 predominance over IgG2a. The production of IL-4 after concanavalin-A stimulation of splenocytes slightly increased among the mouse strains except C3H/HeN after 4 or 8 weeks of infection, but each strain produced high levels of IFN-γ after 8 weeks, which implied mixed Th1/Th2 responses. ICR, DDY, CBA/N, and C3H/HeN strains showed a significantly increased level of IL-10 after 8 weeks as compared to C57BL/6. All of the strains showed an increased level of IL-13 and suggested fibrotic changes in the mice. In conclusion, mice are insusceptible to infection with C. sinensis; however, the C57BL/6, BALB/c and ICR strains are relatively susceptible after 8 weeks of infection among the six strains. Worm expulsion may be one of the causes of low susceptibility of C3H/HeN mice strain at the 8th week. Elevated IgE, IFN-γ, and IL-13 of infected mice suggest both Th1 and Th2 responses that may be related to the low host susceptibility.