Recognition of Trichinella spiralis muscle larvae antigens by sera from human infected with this parasite and its potential use in diagnosis.

Human antibody response to total soluble extract of Trichinella spiralis muscle larvae (TSE) was analyzed by Western blot. The most frequently recognized antigens had molecular weights of 96, 67, 63, 60, 55 and 47 kDa. An antigenic fraction containing two peptides with M.W. of 43, 47 kDa from the parasite (p43, 47 Ts L1) was isolated by elution from polyacrylamide gel slabs. It was used as antigen in an ELISA test and compared to that of TSE. Serum samples from 51 symptomatic trichinellosis patients--43 with high antibody levels to TSE, 5 of them with positive biopsy and 8 with low levels of these antibodies--as well as 38 from asymptomatic individuals from the area where the trichinellosis outbreaks had occurred and 43 from apparently healthy individuals from a non-endemic area, 37 from patients with intestinal parasitic infections caused by helminth and protozoan parasites--11 from recurrent and 26 from non-recurrent disease--were analyzed by ELISA using both antigens. The ELISA using p43, 47 Ts L1 detected all trichinellosis patients with high antibody levels as well as 6 out of 8 of those with low antibody levels. All control groups were negative. Therefore, this purified fraction allowed the ELISA to be more specific and sensitive for human trichinellosis diagnosis.