Changes of IgE production, splenic helper and suppressor T lymphocytes in mice infected with Paragonimus westermani.

Effects of Paragonims westermani infection were observed in mice on the change of serum IgE level, the number of peripheral eosinophils and the distribution of Thy 1.2+ (CD3), L3T4+ (CD4), and Lyt-2+ (CD8) splenic T lymphocytes without mitogen stimulation. BALB/c mice were infected with 20 metacercariae of P. westermani each. Total serum IgE increased at 3 weeks after the infection and reached a peak on week 4 and maintained high levels of IgE until the 23rd week. Peripheral eosinophil numbers increased at the second week and attained peak level on week 9. The frequency of L3T4+ (CD4) and Lyt-2+ (CD8) T lymphocytes decreased slightly until 4 weeks after the infection, but not significantly. Absolute number of L3T4+ and Lyt-2+ T lymphocytes, and the ratio of L3T4/Lyt-2 were not markedly changed over the period of observation. The frequency of Thy 1.2+ (CD3) T lymphocytes in the infected group slightly decreased until 4 weeks after the infection and showed significant reductions at the 2nd and 4th week of the infection (p < 0.05).