Novel Synthetic Peptide-based Enzyme Linked Immunosorbent Assay for Antibody Detection in Viral Infections of the Central Nervous System

Abstract

Introduction: Viral infections of Central Nervous System (CNS) are associated with severe neurological sequelae and can lead to significant morbidity if not adequately diagnosed and treated. An immunological assay detecting antibodies in the Cerebrospinal Fluid (CSF) of the patients is widely used for diagnosis of viral infections of the CNS. In the present study, diagnostic efficacy of in-house designed synthetic peptide based Enzyme Linked Immunosorbent Assay (ELISA) was evaluated for detection of antibodies against neurotropic viruses panel such as Cytomegalovirus (CMV), Epstein-Barr virus (EBV), Varicella Zoster Virus (VZV), Japanese Encephalitis Virus (JEV), Dengue (DENV), West Nile Virus (WNV) and Chandipura Virus (CHPV) in CSF of suspected cases. Aim: To determine the diagnostic efficacy of in-house developed synthetic peptide-based ELISA in viral infections of the CNS. Materials and Methods: A retrospective study was conducted in Central India Institute of Medical Science, Nagpur, Maharashtra, India. The suspected case of CNS viral infections of the patients were enrolled in this study from January 2013 to December 2015. Total 150 suspected cases of viral CNS infections and 135 control cases were recruited. Total 32 synthetic peptides of highly immunogenic proteins of respective seven neurotropic viruses were designed and synthesised. The designed peptides were evaluated in CSF samples of both the viral CNS infections and control cases for detection of Imunoglobulin G (IgG) and IgM antibodies using in-house developed antibody detection method. The developed tests were further compared with commercially available antibody detection ELISA kit. The sensitivity and specificity of peptide-ELISA were determined by Receiver Operating Curve (ROC) analysis and p-value was calculated by comparison of means by t-test. Results: Out of total 150 cases of CNS viral infections, a total of 31 CSF samples including 15 for CMV and 16 of JEV were positive by in-house peptide ELISA. The synthetic peptides STGDVVDISP, KQKSLVEL, RTLEVFKE, RSSNVED of CMV and ITYECPK, RRSVSVQT, GESSLVN of JEV showed a significant difference in mean absorbance value for IgM and IgG antibodies in CSF of suspected cases of viral CNS infection. Conclusion: The results demonstrated that the synthetic peptide-based ELISA is rapid, cost-effective, simple and efficient immunodiagnostic assay for initial screening of viral CNS infection.