Chronic alveolar hydatidosis and secondary amyloidosis: pathological aspects of the disease in four strains of mice.

Amyloidogenic potentials of alveolar hydatid cyst, the larval stage of Echinococcus multilocularis, were studied in BALB/c, C57BL/6J, CBA/J and A/JAX strains of mice. To determine strain susceptibility and sensitivity of various soft organs to amyloidosis, the intensity of inflammation and mean weights of the larval cyst masses from each host strain were correlated at various time intervals postinfection (p.i.) with the onset and amount of splenic, hepatic and kidney amyloid deposits. The onset and incidence of amyloidosis in these four host strains corresponded with the intensity of hepatic inflammation and not with the load of the parasite biomass. Hydatid mice spleens were more sensitive to amyloid deposition than livers or kidneys. Splenic amyloid deposits appeared at 6 weeks p.i. in BALB/c and C57BL/6J mice and at 8 and 12 weeks p.i. in CBA/J and A/JAX mice, respectively. The latter strain was relatively resistant to hydatid-induced amyloidosis. At 12 weeks p.i., amyloid-mediated changes in the spleens, livers and kidneys of the susceptible host strains were much more severe than in the A/JAX strain. In conclusion, alveolar hydatid cyst is highly amyloidogenic and provides a promising substitute for the study of induction and pathogenesis of secondary amyloidosis.