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.

Long-term visual outcome in idiopathic intracranial hypertension.

OBJECTIVE: To characterize the course, outcome, and risk of relapse or late worsening in a clearly defined cohort of idiopathic intracranial hypertension (IIH) over a long period of follow-up. MATERIALS AND METHODS: Retrospective chart review of patients with definite IIH was evaluated at the Sree Chitra Tirunal Institute for Medical Sciences and Technology between 1998 and 2006. Patients' demographic data, clinical, neuro-ophthalmic examinations, and treatment details were abstracted. Patients were further categorized into three groups based on whether they improved, worsened, or relapsed on follow-up. Final visual outcome of each patient was defined according to grading of the worse eye at the last visit. Statistical analysis included t test to compare group means and chi-square test to compare proportions. RESULTS: Of the 43 women included, visual impairment was observed in 80 eyes (93%) at presentation and it was moderate to severe in 14%. The mean CSF opening pressure at presentation did not differ significantly in those with visual impairment compared to those with normal vision. Those having early severe visual impairment had significantly higher (P = 0.015) likelihood of severe visual impairment on last follow-up. Of the total, 34 patients (79%) improved, 4 (9.3%) relapsed on follow-up after period of stability, and 5 (11.6%) worsened over 56 months follow-up (range, 26-132 months). The groups were comparable, except those who improved were younger (P<0.05). At last examination, 9% had significant vision loss. CONCLUSION: IIH patients can have delayed worsening or relapses and about tenth of patients can have permanent visual loss early or late in the course of the disease. All patients with IIH need to be kept under long-term follow-up, with regular monitoring of visual functions.

Effects of atorvastatin on higher functions.

OBJECTIVE: This study was undertaken to assess the effects of atorvastatin on cognition and higher mental functions. METHODS: In this before and after comparison study with controls, group one included 55 subjects aged > or =40 years requiring statins for cardiovascular indications who were started on atorvastatin (10 mg/day). Group two assigned to receive placebo were men and women chosen from the same geographical area and matched for age, sex, education and presence of hypertension and diabetes mellitus. Assessment was done with the Mini-Mental State Examination, Digit Span, Picture Test (average and delayed), Trail Making Test, Controlled Oral Word Association Test, Digit Symbol Substitution Test and Auditory Vigilance and Digit Vigilance Test at baseline and after 6 months. Changes between baseline and 6 months in the above parameters of mental function were compared using suitable statistical tests in the atorvastatin and placebo groups. To limit experiment-wise error, performance scores were grouped into five cognitive domains, which were labeled as attention, psychomotor speed, mental flexibility, working memory and memory retrieval. Summary effect sizes were estimated as z-scores. RESULTS: Both subjects on atorvastatin and placebo showed improvement in the majority of scales consistent with a learning effect on test performance. However, subjects treated with atorvastatin scored significantly over the placebo group in all domains, i.e. tests of attention [z-score=0.54, 95% confidence interval (CI): 0.38-0.64, p=0.001], psychomotor speed (z-score=0.28, 95% CI: O.09-0.47, p<0.001), mental flexibility (z-score=0.27, 95% CI: 0.22-0.32, p=0.01), working memory (z-score=1.22, 95% CI: 0.93-1.50, p<0.001) and memory retrieval (z-score=0.59, 95% CI: 0.36-0.82, p<0.05). CONCLUSION: The present study concludes that there are significant beneficial effects of atorvastatin in a dose of 10 mg/day for a period of 6 months on higher functions as measured by the above standard neurocognitive tests.