Prior infection protects against induced hepatic fibrosis.

Background: Schistosomiasis affects approximately 250 million people worldwide, with 200,000 deaths annually. It has been documented that the granulomatous response to () oviposition is the root cause of progressive liver fibrosis in chronic infection, in 20% of the patients, and can lead to liver cirrhosis and/or liver cancer. The influence of helminths coinfection on schistosomiasis-induced liver pathological alterations remains poorly understood. Therefore, in this study, we investigated the effect of () infection on -induced hepatic fibrosis.

Materials And Methods: Thirty adult male Balb-c mice were divided into three groups. Group 1 was left uninfected; group 2 was infected with cercariae and group 3 was orally infected with larvae, then 28 days later, this group was infected with cercariae. All groups were sacrificed at the end of the 8 week post infection with the effect of pre-infection with on induced liver fibrosis was evaluated parasitologically (worm burden and egg count in tissues), biochemically (levels of alanine aminotransferase and aspartate aminotransferase), histopathologically (H&E and MT staining, and immunohistochemical staining for the expression of α-SMA, IL-6, IL-1β, IL-17, IL-23, TNF-α, and TGF-β).

Results: The results in the present study demonstrated marked protective effect of against induced liver pathology. We demonstrated that pre-infection with caused marked reduction in the number of adult worms (3.17 ± 0.98 vs. 18 ± 2.16, = 0.114) and egg count in both the intestine (207.2 ± 64.3 vs. 8,619.43 ± 727.52, = 0.009) and liver tissues (279 ± 87.2 vs. 7,916.86 ± 771.34; = 0.014). Consistently, we found significant reductions in both number (3.4 ± 1.1 vs. 11.8.3 ± 1.22; = 0.007) and size (84 ± 11 vs. 294.3 ± 16.22; = 0.001) of the hepatic granulomas in mice pre-infected with larvae compared to those infected with only . Furthermore, pre- infection with markedly reduced - induced hepatic fibrosis, as evidenced by decreased collagen deposition, low expression of α-SMA, and significantly reduced levels of IL-17, IL-1B, IL-6, TGF-B, IL-23, and TNF-α compared to mice infected with only.

Conclusions: Our data show that pre-infection with effectively protected mice from severe schistosomiasis and liver fibrosis. We believe that our findings support the potential utility of helminths for the preventing and ameliorating severe pathological alterations induced by schistosomiasis.