Immunodiagnosis of human neurocysticercosis: use of heterologous antigenic particles (Cysticercus longicollis) in indirect immunofluorescence test

The indirect immunofluorescence (IIF) test was standardized using antigenic particles of Cysticercus longicollis (Cl), ORF strain, for the detection of antibodies in cerebrospinal fluid (CSF) in human neurocysticercosis (NC). ELISA with a total saline extract of Cysticercus cellulosae (Cc) and IIF with Cc particles were performed comparatively. The IIF-Cl test presented 84.8% positivity (95% confidence interval (Cl_95%) = 74.2%–95.4%) in 46 CSF samples from patients with NC, 100% negativity in 45 CSF samples from the control group, and 92.3% agreement with ELISA and 98.9% agreement with the IIF-Cc test. No difference was observed between the homologous and heterologous antigens in the IIF test, suggesting that particulate Cl antigens may be employed alternatively in the laboratory diagnosis of NC by the determination of antibodies in the CSF.