We performed this study to investigate the clinical and serological characteristics of human toxocariasis in Korea.
Methods:
Total 152 patients with peripheral eosinophilia (>450 cells/μl) were enrolled and they were divided into two groups based on a Toxocara excretory-secretory IgG ELISA: 95 seropositive patients and 57 seronegative patients. We not only compared the clinical features including age, sex, tissue infiltration of eosinophil and presence of allergic asthma and rhinitis but also serologic markers such as serum total IgE, specific IgE to Dermatophagoides pteronyssinus (Dp) and Dermatophagoides farine (Df) by using immunoCAP between two groups.
Results:
The seropositive rate of toxocara was 62.5% (95/152) in the patients with peripheral eosinophilia in whom seropositive patients were older than seronegative patients (p=0.043), men were more than women (p<0.01). The serum total eosinophils (p=0.048), total IgE level (p<0.01) and the Df seropositive (immunoCAP >0.35 KU/L) rate (p<0.01) were significantly higher in sereopositive patients than seronegative patients. The eosinophilic tissue infiltration in liver (p=0.003) or lung (p<0.01) and ingestion of raw cow meat or liver (p<0.01) were observed more frequently in seropositive patients but the presence of allergic asthma (p<0.01) and rhinitis (p<0.01) more frequnetly in seronegative patients. Among seropositive patients, there were positive correlations between the serum total IgE level, total eosinophils and the value of toxocara IgG ELISA OD (r=0.502, p<0.01 ; r=0.247, p=0.016, respectively) and the specific IgE to Df was significantly higher (p<0.01) than that to Dp suggesting there might be cross reaction between the antigen of Df and toxocara antigen.
Conclusions:
The ingestion of raw cow meat or liver was closely related to an increased risk of toxocariasis in Korea. We thought that the patients who had highly elevated serum total IgE level, peripheral eosinophilia and experience of ingestion of raw cow meat or liver but not allergic disease might have human toxocariasis so should be evaluated whether eosinophils were infiltrated in organs such as liver or lung.