Diagnosis of viral central nervous system infections using antipeptide antibody against viral antigen by ELISA.

Viral infections of the central nervous system (CNS) occur sporadically and have been extensively studied because of the potential for permanent neurological damage or death. The neurotropic viruses have been reported to lead to various CNS infections. The objective of the present study is to develop an antigen detection ELISA protocol for detection and quantification of viral antigen in CNS infections by assessing the usefulness of antipeptide antibodies against potential peptides of cytomegalovirus (CMV), Epstein-Barr virus (EBV), varicella zoster virus (VZV), Japanese encephalitis virus (JEV), dengue (DENV), West Nile virus (WNV) and Chandipura virus (CHPV). A total of 182 cerebrospinal fluid (CSF) samples from confirmed, suspected and non-viral infections of the CNS were evaluated using panels of antipeptide antibodies against synthetic peptides of viral proteins. The cases of confirmed and suspected viral infections of the CNS showed 77% and 11% positivity, respectively, for the detection of viral antigen using antipeptide against synthetic peptides of CMV, EBV, VZV and JEV. The concentration of viral antigen was also obtained by using antipeptide of respective viruses in CSF from both the groups. The viral antigen concentration was also correlated with viral load in confirmed cases of viral infection of the CNS. This study demonstrates the use of antipeptide against synthetic peptide derived from CMV, EBV, VZV and JEV in diagnostics of viral infections of the CNS using patients' CSF samples. Keywords: viral infection of the CNS; synthetic peptide; antipeptide antibody; viral load; antigen concentration.

Identification of an immunodominant epitope in glycoproteins B and G of herpes simplex viruses (HSVs) using synthetic peptides as antigens in assay of antibodies to HSV in herpes simplex encephalitis patients.

Herpes simplex encephalitis (HSE) is a severe viral infection of the central nervous system (CNS). Assay of antibody response is widely used in diagnostics of HSE. The aim of this study was to identify an immunodominant epitope determining the antibody response to herpes simplex viruses (HSVs) in cerebrospinal fluid (CSF) of HSE patients. The synthetic peptides that resembled type-common as well as type-specific domains of glycoproteins B (gB) and G (gG) of these viruses were evaluated for binding with IgM and IgG antibodies in CSF samples from HSE and non-HSE patients in ELISA. The QLHDLRF peptide, derived from gB of HSV was found to be an immunodominant epitope in the IgM and IgG antibody response. The patients with confirmed and suspected HSE showed in ELISA against this peptide 26% and 23% positivities for IgM, 43% and 37% positivities for IgG and 17% and 15% for both IgM and IgG antibodies, respectively. The total positivities of 86% and 75% for both IgM and IgG antibodies were obtained in the patients with confirmed and suspected HSE, respectively. These results demonstrate that a synthetic peptide-based diagnostics of HSE can be an efficient and easily accessible alternative. This is the first report describing the use of synthetic peptides derived from HSVs in diagnostics of HSE using patientsʹ CSF samples.

Demonstration of IgG antibodies to 30 Kd protein antigen in CSF for diagnosis of tuberculous meningitis by antibody-capturing ELISA.

OBJECTIVE: A simple and rapid immunological assay method has been developed to demonstrate the presence of IgG antibodies to 30Kd protein antigen (30Kdpa) and culture filtrate protein (CFP) in the CSF of patients with Tuberculous meningitis (TBM). METHOD: Antibody capturing Enzyme Linked Immunosorbent Assay (ELISA) was standardized with CFP antigen of MTB. The IgG antibodies were assayed in CSF sample from TBM and non-TBM patients against 30 Kdpa. RESULTS: The sensitivity and specificity of IgG antibodies for the diagnosis of suspected patients of TBM using 30 Kdpa was 80% and 91% respectively and the corresponding figures for CFP were 85% and 94% respectively. The sensitivity and specificity in two confirmed cases of TBM was 100%. CONCLUSION: The presence of this 30Kdpa in the CSF of suspected cases of TBM consistently would indicate that the selected protein band carries the candidate protein marker antigen, which is specific to M. tuberculosis and could be considered as a diagnostic marker for TBM.