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Biomedical subjects

A Chandramuki

Publications and source records attributed to A Chandramuki.

36 records · Page 2Linked to original sources
PubMed1994

Detection of autoantibodies to neural antigens in the CSF of Japanese encephalitis patients and correlation of findings with the outcome.

This study reports the detection of autoantibodies to myelin basic protein (MBP) and neurofilament proteins (NFP) in serum and cerebrospinal fluid (CSF) of Japanese encephalitis patients. The diagnosis of Japanese encephalitis was confirmed in 72 patients by the presence of virus specific antibodies to JEV in the CSF (28/72), viral antigen in the CSF (19/72) and simultaneous presence of both antigen and JEV antibodies in the CSF in 25/72 patients. Autoantibodies to either purified NFP (10) or MBP (8) or both (17) were detected in the CSF of 35 patients by ELISA in contrast with the control CSF samples. Amongst them 20 had similar antibodies in the serum as well. Correlation of immunological findings with the clinical outcome revealed that the presence of autoantibodies in the CSF especially to NFP was associated with a fatal outcome (P < 0.05).

Adolescent↗
PubMed1994

Detection of Japanese encephalitis virus antigens in the CSF using monoclonal antibodies.

BACKGROUND: Antigen detection in the CSF is an invaluable tool in the diagnosis of viral infections of the nervous system, especially in the early phase of the illness. Very little information is available on the use of antigen detection in the diagnosis of Japanese encephalitis (JE). OBJECTIVES: Evaluation of two monoclonal antibody-based antigen detection methods in the diagnosis of JE in comparison with the detection of virus-specific IgM antibodies in the CSF. STUDY DESIGN: In this study 115 patients with a clinical diagnosis of JE were investigated. A reverse passive haemagglutination test for the detection of soluble JEV antigens, an immunofluorescent assay for the detection of cell-associated antigen and an IgM capture ELISA for the detection of virus specific IgM antibodies in the CSF were used. RESULTS: Laboratory confirmation of JE was possible in 92/115 patients. Virus-specific IgM was detected in 75/92 and JEV antigen was detected in 52/92 patients. Soluble antigen was detected in 37/52, cell-associated antigen in 30/52. There was no significant difference in the sensitivity of the two antigen detection systems used. CONCLUSIONS: Diagnosis by antigen detection could be done less frequently than by demonstration of virus-specific IgM antibodies in the spinal fluid. However, antigen detection proved useful during the first week of illness when IgM antibodies were not detected in the CSF.

Journal Article↗
PubMed1994

Association of Japanese encephalitis virus infection with Guillain-Barré syndrome in endemic areas of south India.

This study is a report of 34 cases of Guillain-Barré syndrome (GBS) observed in Bangalore (South India), an endemic area for Japanese encephalitis virus (JEV) infection. Virological and immunological findings suggested an antecedent and recent JEV infection in 21/34 patients. Nineteen patients among them showed high levels of JEV-specific IgM antibodies in serum and/or CSF, while the viral antigen could be demonstrated in one case and virus isolation from the CSF was successful in one patient. EMG studies revealed features of predominantly demyelinating neuropathy in 18/25 cases. Comparison of clinical findings, duration of illness and outcome in GBS patients with evidence of JEV infection and those without did not reveal any differences. Pathological findings in one patient corroborated the association of JEV with GBS. We conclude that, JEV infection may predispose to Guillain-Barré syndrome in endemic areas.

Adolescent↗
PubMed1994

Detection of immune complexes in the CSF of Japanese encephalitis patients: correlation of findings with outcome.

This paper reports the direct evidence for the presence of Japanese encephalitis virus (JEV)-specific immune complexes in the CSF of 31/185 confirmed patients for the first time. A monoclonal antibody-based capture ELISA was used for the detection of immune complexes. Amongst the 31 cases positive for immune complexes, 14 were positive for JEV IgM antibodies and/or neutralizing antibodies in the CSF, 6 were positive for viral antigen in the CSF and 11 for both antibody and antigen. Correlation of findings to final outcome revealed that the presence of immune complexes in CSF was significantly associated with death (p = 0.01).

Adolescent↗
PubMed1994

The role of immunological & virological techniques in the diagnosis of herpes simplex encephalitis.

The efficacy of immunological and virological methods in the diagnosis of herpes simplex encephalitis (HSE) was studied in 22 patients diagnosed as HSE by clinical, radiological EEG parameters. CSF cell counts were elevated in 14 of 18 patients with a lymphocytic predominance in 13. Virus specific IgG antibody detection by ELISA in paired CSF samples was possible in 8 of 17 patients. HSV antigen could be detected by immunohistochemical methods in the cells of the CSF and/or brain tissue in 7 of 9 patients. In four of them antemortem diagnosis was possible facilitating prompt specific antiviral therapy. Virus isolation was possible in 2 of 8 patients, one from brain biopsy tissue and the other from brain tissue obtained at autopsy. Using all the three methods, the diagnosis of HSE could be confirmed in 14 of 22 (63.6%) patients.

Adolescent↗
PubMed1993

Persistence of Japanese encephalitis virus in the human nervous system.

Immunological and virological evidence for persistence of Japanese encephalitis virus (JEV) in the human nervous system is described in 16/323 (5%) laboratory-confirmed cases of Japanese encephalitis. In 9/16 patients, JEV specific IgM antibodies were detected in the CSF even at 50-180 days after the onset of symptoms. Similarly, in 7/16 patients, apart from IgM antibodies, viral antigen was also present in the CSF beyond the third week of illness and in one patient it could be detected even at 117 days. Infectious virus could be isolated from the CSF beyond the third week of illness in 3/16 patients. In one patient, JEV was isolated from the CSF on three consecutive occasions at 90, 110, and 117 days after onset of clinical symptoms. These findings suggest that JEV persists in the nervous system of a small proportion of patients.

Adult↗
PubMed1990

Antigenic analysis of Cysticercus cellulosae by crossed immunoelectrophoresis & its role in immune diagnosis of neurocysticercosis.

The antigenic composition of Cysticercus cellulosae cysts excised from infected pig and autopsied human brain was analysed by crossed immunoelectrophoresis with an intermediate gel technique using rabbit hyperimmune serum. Normal pork muscle and human brain antigen were used to differentiate parasite derived components from that of host. Attempts were made to look for the rich source of parasitic immunodominant antigens by analysing preparations of different parts of cyst namely scolex and fluid using rabbit hyperimmune serum. Twenty three antigenic components were identified in sonicate extract of porcine cyst, of which 15 were parasite derived. On comparison with antigens of whole cyst sonicate, scolex showed 10, cyst fluid 9 and human cyst sonicate 11 parasite derived antigens. Serum and cerebrospinal fluid (CSF) of neurocysticercotic patients reacted with 12 parasite derived antigens of porcine cyst sonicate (PCS) in a heterogenous manner. It was also noticed that human cyst sonicate (HCS) lacked 4 of the parasite derived antigens present in the PCS.

Animals↗
PubMed1989

Laboratory diagnosis of Japanese encephalitis using monoclonal antibodies and correlation of findings with the outcome.

Detection of virus, viral antigen, and class-specific antibody was carried out in cerebrospinal fluid (CSF) and sera of 27 children with Japanese encephalitis. The diagnosis could be confirmed in 78.57% of cases (22/27) by demonstration of virus-specific IgM in CSF (15/22), viral antigen in CSF (5/22), or by virus isolation (2/22). Absence of virus specific IgM in CSF was associated with a fatal outcome (P = 0.05).

Adolescent↗
PubMed1989

A reverse passive haemagglutination test for detection of Japanese encephalitis virus antigens in cerebrospinal fluid.

A rapid sensitive and specific reverse passive haemagglutination test (RPHA) was developed for the detection of Japanese encephalitis virus (JEV) antigens in human cerebrospinal fluid (CSF). Sheep red cells were sensitized with five monoclonal antibodies (109, 112, 203, 204 and 301) reactive with envelope glycoprotein of JEV. Viral antigens were detected in CSF from 35 of 58 (60%) clinical cases of JE when the five MAb coated cells were used in combination. An IgM capture ELISA detected JEV specific antibodies in CSF among 52 of these 58 cases (90%). While 29 specimens contained both antigen and IgM antibodies, 23 had only IgM antibodies and 6 had only antigen. RPHA proved valuable for detection of viral antigens in CSF samples obtained within 10 days after onset of clinical symptoms. Amongst the five MAbs used, the individual antigen detection rates were 44, 12, 43, 12 and 36%, for MAbs 109, 112, 203, 204 and 301, respectively.

Animals↗
PubMed1989

Levels of antibody to defined antigens of Mycobacterium tuberculosis in tuberculous meningitis.

The aim of the study was to develop an antibody immunoassay for tuberculous meningitis with a sensitivity greater than that of the initial bacterial smear while maintaining a 100% specificity. Antibody titers to five purified antigens of Mycobacterium tuberculosis were measured in cerebrospinal fluid by using an enzyme-linked immunosorbent assay technique. Seventy-four patients with tuberculous meningitis (26 culture positive) were compared with 26 patients with purulent meningitis, 69 patients with suspected but excluded tuberculous meningitis, and 29 patients with other neurological diseases. Antibody responses to both the 14-kilodalton (kDa) antigen and lipoarabinomannan were immunodominant, accounting for 74% of those with any antibody titer to a soluble extract of M. tuberculosis. A sensitivity of 61% was achieved (77% for the culture-positive samples) by using immunoglobulin G titers to lipoarabinomannan and the 14-, 19-, and 38-kDa antigens. Thus, estimation of levels of antibody in cerebrospinal fluid to selected mycobacterial antigens would be valuable in the diagnosis of tuberculous meningitis. The possible reasons for the immunodominance of the 14-kDa antigen and lipoarabinomannan in the pathogenesis of tuberculous meningitis are discussed.

Antibodies, Bacterial↗
PubMed1985

Detection of mycobacterial antigen and antibodies in the cerebrospinal fluid of patients with tuberculous meningitis.

An immunodiagnostic test for the detection of a soluble nonprotein mycobacterial antigen by reverse passive haemagglutination with IgM murine monoclonal antibody was developed. The test was used to analyse the cerebrospinal fluid of 89 patients with tuberculous meningitis (TBM) from India and 127 control subjects from India and the UK. The antigen was demonstrable in 88% of culture-positive and 73% of culture-negative TBM patients. However, it was also detected in 21% of Indian patients with pyogenic meningitis, and in 8% of Indian and 1% of UK control subjects. Antibodies binding to a soluble mycobacterial extract were detected at low titre in 68% of all subjects with TBM and in 37% of Indian cases of pyogenic meningitis. Because patients with TBM had raised levels of the antigen and of antibodies to the antigen, the possible role of immune complexes in the pathogenesis of the disease is briefly discussed.

Antibodies, Bacterial↗
PubMedDate not supplied

Sub acute and chronic meningitis in children--an immunological study of cerebrospinal fluid.

Cerebrospinal fluid (CSF) from 274 cases of subacute to chronic meningitis in age groups from 3 months to 12 years were analysed for the presence of antibody response to mycobacterial and cysticercal antigens by enzyme linked immunosorbent assay (ELISA). Simultaneously other correlative parameters such as CSF cell cytology by cytospin studies, mycobacterial antigens of Lipoarabinomannan (LAM) type (a polysaccharide antigen) by reverse passive haemagglutination assay (RPHA) CSF C-reactive protein (CRP) by latex agglutination and microbial cultures for mycobacterium tuberculosis and fungi were carried out. Antimycobacterial antibody was present in 35.4% of the cases. In 57.66% of the cases there was no demonstrable immune response to either mycobacterial or cysticercal antigens. However, it was interesting to note that 5.47% of the cases revealed the presence of anticysticercal antibody in the CSF. The mycobacterial antigen (LAM polysaccharide antigen) was found in 72.6% of the cases. There was no evidence of carcinomatous or cryptococcal meningitis. This study stresses the role of multimodal diagnostic tests on CSF for investigating cases of chronic and subacute meningitis irrespective of leading clues such as tuberculosis.

Acute Disease↗
PubMedDate not supplied

Cryptococcosis in the immunocompromised host with special reference to AIDS.

Cryptococcosis is increasing because of an ever rising population of immunocompromised individuals especially those with acquired immune deficiency syndrome (AIDS). Cryptococcal infection of the central nervous system (CNS) were diagnosed in 149 cases over a period of 19.5 years (January 1978-June 1998). Culture was positive in all cases except three who were already on antifungal therapy. India ink mounts of cerebrospinal fluid (CSF) revealed encapsulated cryptococci in 134, and cryptococcal antigen was detected in 111 of 114 patients tested. A comparison of laboratory and certain clinical parameters in patients with and without associated HIV infection showed that a poor CSF cell response and culture of cryptococci from extra-neural sites was more often associated with HIV infection and was statistically significant. Further, presence of concomitant infection especially tuberculosis, and mortality were higher in the HIV positive group.

AIDS-Related Opportunistic Infections↗