Pewpan M Intapan1, Wanchai Maleewong1, Chaisiri Wongkham2, Nimit Morakote3, Wanpen Chaicumpa4 
1Department of Parasitology, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand; 2Department of Biochemistry, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand; 3Department of Parasitology, Faculty of Medicine, Chiang Mai University, Chiang Mai 50200, Thailand; 4Department of Microbiology and Immunology, Faculty of Tropical Medicine, Mahidol University, Bangkok 10400, Thailand 

Abstract 
A monoclonal antibody (MAb) capture enzyme-linked immunosorbent assay (MAb capture ELISA) was developed and evaluated for its application in the detection of circulating antibodies to Paragonimus heterotremus in infected human sera. Mouse IgG monoclonal antibodies derived from a hybridoma clone 10F2 which reacted to 31.5 and 22 kDa components of the excretory-secretory (ES) antigen of the parasite were used to sensitize a microtiter plate; the bound antibodies captured their respective epitopes in the subsequent added ES antigen. Individual sera of patients with either parasitologically confirmed paragonimiasis heterotremus, other parasitic infections or pulmonary tuberculosis, and parasite-free healthy controls were incubated to the appropriate IgG-antigen containing wells. Finally, the bound human antibodies were detected by the anti-human immunoglobulin-horseradish peroxidase conjugate and substrate. The MAb capture ELISA had 100%, 97%, 91.6% and 100% diagnostic sensitivity, diagnostic specificity, and positive and negative predictive values, respectively, when tested on sera of 33 patients with parasitologically confirmed paragonimiasis heterotremus, 68 patients with other parasitic infections, eight patients with pulmonary tuberculosis and 29 normal controls. The MAb capture ELISA offers an alternative for sensitive and specific diagnosis of paragonimiasis by means of antibody detection without the requirement of purified, specific antigen of the parasite. Keywords: Paragonimus heterotremus, paragonimiasis, excretory-secretory antigen, immunodiagnosis, monoclonal antibodies, ELISA