Eosinophil degranulation plays a crucial role in tissue inflammatory reactions associated with helminth parasitic nfections and allergic diseases. Paragonimus westermani, a lung fluke causing human paragonimiasis, secretes a large amount of cysteine proteases, which are involved in nutrient uptake, tissue invasion, and modulation of hos's immune responses. There is, however, limited information about the response of eosinophils to direct stimulation by cysteine proteases (CP) secreted by P. westermani. In the present study, we tested whether degranulation and superoxide production from human eosinophils can be induced by stimulation of the 2 CP (27 kDa and 28 kDa) purified from excretory-secretory products (ESP) of P. westermani newly excysted metacercariae (PwNEM). A large quantity of eosinophil-derived neurotoxin (EDN) was detected in the culture supernatant when human eosinophils isolated from the peripheral blood were incubated with the purified 27 kDa CP. Furthermore, the 27 kDa CP induced superoxide anion production by eosinophils in time- and dose-dependent manners. In contrast, the purified 28 kDa CP did not induce superoxide production and degranulation. These findings suggest that the 27 kDa CP secreted by PwNEM induces superoxide production and degranulation of human eosinophils, which may be involved in eosinophil-mediated tissue inflammatory responses during the larval migration in human paragonimiasis.
Animals ; Astacoidea/parasitology ; *Cell Degranulation ; Cysteine Endopeptidases/*immunology/isolation & purification ; Eosinophils/*immunology/metabolism ; Helminth Proteins/*immunology/isolation & purification ; Humans ; Paragonimiasis/*immunology/metabolism ; Paragonimus westermani/*enzymology/isolation & purification ; Superoxides/*immunology

Seroprevalence of the IgG antibodies for Clonorchis sinensis, Paragonimus westermani, Taenia solium metacestode (cysticercus), and Spirometra erinacei plerocercoid (sparganum) was measured using enzyme-linked immunosorbent assay (ELISA) in sera of patients in Korea from 1993 to 2006. A total of 74,448 specimens referred nationwide from 121 hospitals revealed an IgG positive rate of 7.6% for the 4 parasites. The IgG positive rate (18.7%) for the 4 parasites in 1993 decreased gradually to 6.6% in 2006. Individual positive rate decreased from 5.2% (1993) to 1.6% (2006) for C. sinensis, from 2.8% (1993) to 1.1% (2006) for P. westermani, from 8.3% (1993) to 2.2% (2006) for cysticercus, and from 2.6% (1993) to 1.6% (2006) for sparganum. The positive rate was highest (21.2%) in the group of patients who ranged in age from 50-59 yr old, and in the group that was referred from the Seoul area (55.9%). In conclusion, our results suggest that tissue invading parasitic infections should always be included in differential diagnosis for patients with eosinophilia associated lesions of the central nervous system, liver, and lungs in Korea.
Adolescent ; Adult ; Age Factors ; Aged ; Aged, 80 and over ; Animals ; Antibodies, Helminth/*blood ; Child ; Child, Preschool ; Clonorchiasis/diagnosis/*epidemiology ; Clonorchis sinensis/immunology/isolation & purification ; Cysticercosis/diagnosis/*epidemiology ; Cysticercus/immunology/isolation & purification ; Diagnosis, Differential ; Enzyme-Linked Immunosorbent Assay ; Eosinophilia/immunology ; Female ; Humans ; Immunoglobulin G/blood ; Infant ; Male ; Middle Aged ; Paragonimiasis/diagnosis/*epidemiology ; Paragonimus westermani/immunology/isolation & purification ; Republic of Korea/epidemiology ; Seroepidemiologic Studies ; Sparganosis/diagnosis/*epidemiology ; Sparganum/immunology/isolation & purification