To investigate the prevalence of specific anti-Toxocara IgG and IgE antibodies in ocular toxocariasis by means of ELISA and Western blotting, serum samples of 105 cases with uveitis of unidentified etiology were randomly selected from our stocked sera, which were referred to the Section of of Environmental Parasitology of Tokyo Medical and Dental University for detection of the anti-Toxocara antibody. By using ELISA, 82 of them (78.1%) were negative for both IgG and IgE antibodies, 12 (11.4%) were positive only for IgG, three (2.9%) were positive only for IgE, and eight (7.6%) were positive for IgG and IgE. Among the positive samples, as demonstrated by western bloting the IgG reacting bands were found to distribute in the whole range of molecular weights (97.2-14.3kDa)of excretory-secretory products of T. canis larvae. On the other hand,IgE antigenic molecules were concentrated on a relatively narrow range from 45kDa to 29kDa. In this study, we clearly demonstrated that some of the patients with uveitis showed specific anti-Toxocara IgE antibody but not IgG antibody in serum sample, suggesting that the demonstration of specific IgE antibody should be considered for the precise diagnosis of ocular toxocariasis. Further studies are needed to clarify the diagnosis significance of specific IgE antibody in ocular toxocariasis.

We encountered a probable case of loiasis in a returned traveler from Central Africa. A 52-year-old Japanese woman presented to our hospital complaining of discomfort in her eyes and skin. She reported having frequently visited Central Africa over many years and having been extensively exposed to the rainforest climate and ecosystem. Although no microfilariae were found in her blood, there was an elevated level of IgG antibodies against the crude antigens of Brugia pahangi, which have cross-reactivity with Loa loa. She was treated with albendazole for 21 days, after which the antigen-specific IgG level decreased and no relapse occurred.

We encountered a probable case ofloiasis in a returned traveler from Central Africa. A 52-year-old Japanese womanpresented to our hospital complaining of discomfort in her eyes and skin. She reportedhaving frequently visited Central Africa over many years and having been extensivelyexposed to the rainforest climate and ecosystem. Although no microfilariae werefound in her blood, there was an elevated level of IgG antibodies against thecrude antigens of Brugia pahangi,which have cross-reactivity with Loa loa.She was treated with albendazole for 21 days, after which the antigen-specificIgG level decreased and no relapse occurred.

Immunobiological roles of schistosome eggs during murine experimental infection were investigated with special reference to the induction of basophilic leukocytes. After single- or bisexual infection with Schistosoma mansoni in BALB⁄c mice, splenomegaly and liver granulomas were observed only in bisexual infection in parallel with deposition of mature parasite eggs. Comparison of the kinetics of basophil response revealed a marked increase in number in the bone marrow of mice with bisexual infection at the 7^th week post infection as opposed to a marginal increase in single- sex infections. In the spleen, bimodal response was observed in the basophil responses; a small but repeatable peak at the 4^th week after infection, increasing again at the 8^th week, which corresponded to the initiation and maturation of parasite eggs in the affected organs of infected mice. The same time course was observed for IL-4 production by the splenocytes from mice of bisexual infection. To obtain more concrete evidence of the role of eggs in the induction of basophils, we tested using the intravenous egg injection model. Injection of eggs induced basophilia, and it was accompanied by the up-regulation of IL-4 production in splenocytes from the 8^th day. Basophils induced in this model showed a high level of IL-4 production confirmed by flow cytometry, while faint levels of IL-4 production were observed for CD4⁺ T cells at this time point. In addition, we demonstrate that egg deposition is the trigger of basophil induction and activation in the murine experimental model of S. mansoni infection, which might play an essential role in the initiation of Th1⁄2 conversion during the course of S. mansoni infection in vivo.