Serodiagnosis of Neurocysticercosis in Children with the Use of T. solium cysticerci Excretory Secretory Antigens by Elisa and Immunoblotting

Abstract

Background: Neurocysticercosis (NCC) caused by T. solium (Tso) cysticerci is a leading cause of seizures and epilepsy in the developing world and is an increasingly important health issue in Indian children. Although CT/MRI is considered as a gold standard for the diagnosis of NCC, because of its unavailability and high cost, its application was limited in the developing countries. The sensitivity and specificity of various available serological techniques was low in case of single cysticercus granuloma cases which is a more common feature in Indian children than multilesional neurocysticercosis cases. Excretory Secretory (ES) antigens have been proved as a better diagnostic antigen than crude soluble antigen in many parasitic infections. The present study was aimed to evaluate the ES antigens for antibody detection in serum by ELISA and immunoblotting for the diagnosis of NCC. Methods: Serum samples were collected from 125 clinically suspected and radiologically proven NCC patients and 125 control subjects. The Tso cysticerci was isolated from the naturally infected pigs and cultured in RPMI 1640 medium and ES antigen was prepared by (NH4)2SO4 precipitation method. The ES antigen was used in ELISA and immunoblot for the diagnosis of NCC in children. Results: The sensitivity and specificity of the ES antigen ELISA was 61.6% and 76.8% respectively. In SDS-PAGE analysis of ES antigen, 29 antigenic fractions were identified in between the molecular weight 20—325KDa. The analysis of immunoblot results revealed one highly immunoreactive antigenic fraction with the molecular weight of 74.9 KDa with serum samples. Out of 125 NCC and 125 control serum samples, the immunoreactivity of 74.9 KDa antigenic fraction was 67.2% and 28% respectively. Conclusion: The study suggests that ES antigens appear to be the best diagnostic antigen than crude and other antigens available for detection of antibody in serum samples for the diagnosis of neurocysticercosis in children.