Blood–brain barrier dysfunction occurring in mice infected with Angiostrongylus cantonensis

Several indices were used to assess whether blood–brain barrier (BBB) damage occurs in neurological disorders. Dysfunction of the BBB was surmised to be involved in the pathological changes of eosinophilic meningitis caused by the infection of Angiostrongylus cantonensis. The mean concentration of protein and albumin in the cerebrospinal fluid (CSF) of infected mice gradually increased from days 0 to 18 after infection and then rapidly increased 21 days after infection. The concentrations of protein and albumin in the CSF of infected mice 15 days after infection were all significantly higher than those in uninfected mice (all P-values at least <0.05). Parallel with the increase in protein and albumin in the CSF, infected mice showed a gradual increase in their CSF/serum protein and albumin ratios. The increase became significant at days 21 and 18 after infection, respectively (P < 0.01 and P < 0.05, respectively). The higher the worm counts in the brain, the higher the CSF/serum albumin ratio was observed in infected mice at day 21 after infection (P < 0.001). In addition, the ratios of the CSF/serum albumin were positively correlated with the worm counts in the brain (P < 0.001). The total leukocyte and eosinophil counts were also positively correlated with ratios of CSF/serum albumin (P < 0.01). The amount of Evans blue in the brain of mice 21 days after infection from peripheral blood via BBB became significantly increased than those in uninfected mice (P < 0.001). Thus, the evidence of high concentrations of protein and albumin, high leukocyte counts in CSF, high ratio of CSF/serum protein and albumin, and high permeability of BBB show that dysfunction of the BBB occurred in mice infected with A. cantonensis.