Cysticercosis Immunodiagnosis Using 18- and 14-Kilodalton Proteins from Taenia crassiceps Cysticercus Antigens Obtained by Immunoaffinity Chromatography

Abstract

Monoclonal antibodies (MAb) against Taenia crassiceps and Taenia solium cysticerci were produced and showed cross-reactivity with a 14-kDa protein from T. solium and with 18- and 14-kDa proteins from T. crassiceps. These MAbs and antibodies from cerebrospinal fluid (CSF) as well as serum samples from patients with neurocysticercosis (NC) reacted with 18- and 14-kDa T. crassiceps proteins purified by immunoaffinity chromatography using a Sepharose column coupled with MAbs (anti-excretory/secretory or anti-vesicular fluid antigens). Immunoaffinity-purified 18- and 14-kDa proteins were used in the design of a diagnostic enzyme-linked immunosorbent assay (ELISA) to detect antibodies in 23 CSF and 20 serum samples from patients with NC, showing 100% sensitivity. The test specificity was determined using 42 noninflammatory CSF samples and 70 inflammatory CSF samples from patients with other neurological disorders (OND), showing 100% and 99.1% (confidence interval, 97.3% to 100%) specificity, respectively. A false-positive CSF sample result in the OND group was from a human immunodeficiency virus-positive patient with meningoencephalitis. By using serum samples from 194 healthy individuals, the specificity was 100%. Analysis of an additional 16 serum samples from individuals with other parasitic diseases (13 with intestinal parasitosis and 3 with schistosomiasis) showed negative results. Three (10%) serum samples from patients with hydatidosis were positive in our ELISA and in ELISA with T. solium cysticerci antigens. Two of them were also positive by immunoblotting. The use of 18- and 14-kDa T. crassiceps immunoaffinity-purified proteins for detection of anti-cysticercus antibodies in CSF and/or serum samples using an ELISA system showed a good performance and high specificity for serum samples, dispensing with the use of confirmatory tests, such as immunoblotting, for checking specificity.