Serum tumour necrosis factor-alpha and soluble tumour necrosis factor receptors levels in patients with Guillain-Barre syndrome.

OBJECTIVES: To estimate the serum concentrations of Tumour Necrosis Factor alpha (TNF-alpha) and soluble TNF receptors (s TNF-RI and TNF-RII) in patients with Guillain-Barre syndrome (GBS), before and after treatment. MATERIAL AND METHODS: The serum TNF-alpha and the soluble TNF receptors concentrations were measured by a sandwich enzyme-linked immunosorbent assay (ELISA) in 47 patients with GBS before and after the treatment - IVI therapy (n=26); Plasma Exchange (n=21). RESULTS: At the time of admission, the serum TNF-alpha concentrations were elevated (32.5-182.5 pg/ml) in 41/47 GBS patients (87.2%). Following the treatment (IVIG or PE), there was a significant decrease in the serum TNF-alpha concentrations (8.5-58.5 pg/ml) in these 41 GBS patients. The soluble TNF receptors, particularly sTNF-RII concentrations were significantly increased in GBS patients treated by IVIG therapy. CONCLUSIONS: The results of this indicated that (a) Elevated serum concentrations of TNF-alpha showed a positive correlation with the disease severity in patients with GBS. (b) The decrease in the serum TNF-alpha and increase in the serum soluble TNF receptors, particularly sTNF-RII showed a positive correlation with the neurological recovery in GBB patients following treatment.

Circulating tumour necrosis factor alpha & soluble TNF receptors in patients with Guillain-Barre syndrome.

BACKGROUND & OBJECTIVES: Tumour necrosis factor-alpha (TNF-alpha) is regarded as one of the immune factors that can induce demyelination of peripheral nerves in patients with Guillian-Barre syndrome (GBS). This present study was undertaken to find out the role of TNF-alpha and soluble TNF receptors in the pathogenesis of GBS; and to study the effect of intravenous immunoglobulin (ivIg) therapy on the serum TNF-alpha and soluble TNF receptors in patients with GBS. METHODS: Thirty six patients with GBS in progressive stages of motor weakness were included in this study. The serum TNF-alpha and soluble TNF receptors (TNF-RI, TNF-RII) were measured in the serum samples of these patients before and after ivIg therapy by a sandwich ELISA. RESULTS: Of the 36 patients with GBS, 26 (72.2%) showed elevated serum TNF-alpha levels prior to ivIg therapy. Following a complete course of ivIg therapy there was a progressive decrease in the serum TNF-alpha concentrations in these 26 patients. On the other hand, the soluble TNF receptors, particularly TNF-RII showed an increase in the serum of GBS patients following ivIg therapy. INTERPRETATION & CONCLUSION: The results indicate that ivIg reduces the serum TNF-alpha concentrations in the GBS patients having elevated levels prior to ivIg therapy. Elevated serum levels of soluble TNF receptors following ivIg therapy may play a protective role by inhibiting the demyelinating effect of TNF-alpha in the peripheral nerves of patients with GBS.

Intravenous immunoglobulin reduces serum tumor necrosis factor alpha in patients with Guillain-Barre syndrome.

BACKGROUND: Tumor necrosis factor a TNF-alpha has a possible role in the pathogenesis of the Guillain-Barre syndrome (GBS). AIMS: To study the effect of intravenous immunoglobulin (IVIg) on serum TNF-alpha concentrations in patients with GBS. MATERIAL AND METHODS: The effect of IVIg on TNF-alpha was evaluated in 36 patients with GBS. Serum TNF-alpha concentration was measured by enzyme-linked immunosorbent assay (ELISA). The sera of 22 (61%) patients with GBS showed elevated concentrations of TNF-alpha (35-182 pg/ml) and these sera were individually incubated in vitro with IVIg (0.25 mg/ml) at 37 degrees C for 24 hours. RESULTS: The serum TNF-alpha concentrations in the 22 GBS patients with elevated levels showed a steady decline (60.34-19.78 pg/ml) following incubation with IVIg. These 22 patients also received IVIg therapy, and serum TNF-alpha concentrations showed a significant decline (65.5-9.75 pg/ml) at the end of the therapy. At the time of discharge from the hospital, there was a positive correlation between neurological recovery and decline in TNF-alpha concentrations in these 22 GBS patients. CONCLUSIONS: The results of this study indicate that elevated levels of TNF-alpha occur in a proportion of patients with GBS and in these patients elevated serum TNF-alpha levels decline with IVIg therapy.

Immunocytochemical method for early laboratory diagnosis of tuberculous meningitis.

A simple immunocytochemical method was standardized for the direct demonstration of mycobacterial antigen in cerebrospinal fluid (CSF) specimens of patients with tuberculous meningitis (TBM). CSF-cytospin smears were prepared from 22 patients with a clinical diagnosis of TBM and also from an equal number of patients with nontuberculous neurological diseases (disease control). Immunocytological demonstration of mycobacterial antigens in the cytoplasm of monocytoid cells was attempted, by using rabbit immunoglobulin G to Mycobacterium tuberculosis as the primary antibody. Of the 22 CSF-cytospin smears from TBM patients, 16 showed positive immunostaining, while all of the CSF-cytospin smears from the disease control showed negative immunostaining for mycobacterial antigen. The technical aspects of this immunocytological method for the demonstration of mycobacterial antigens are simple, rapid, and reproducible, as well as specific, and therefore can be applied for the early diagnosis of TBM, particularly in patients in whom bacteriological methods did not demonstrate the presence of M. tuberculosis in the CSF.

A comparative evaluation of dot immunobinding assay (Dot-Iba) and polymerase chain reaction (PCR) for the laboratory diagnosis of tuberculous meningitis.

The results of a Dot immunobinding assay (Dot Iba) for the detection of mycobacterial antigen in the cerebrospinal fluid (CSF) of 45 patients with tuberculous meningitis (TBM) were compared with the results of a polymerase chain reaction (PCR) for the detection of Mycobacterium tuberculosis. In eight patients with culture proven TBM, Dot-Iba gave positive results, while PCR yielded positive results only in six patients. The overall sensitivities of Dot-Iba and PCR in 37 patients with culture negative (probable) TBM were 75.67% and 40.5% respectively. Dot-Iba, in contrast to PCR is a rapid and relatively easier method. More importantly, Dot-Iba is suitable for the routine application for the laboratory diagnosis of TBM and therefore best suited to laboratories in the developing world.

Diagnostic utility of polymerase chain reaction and immunohistochemical techniques for the laboratory diagnosis of intracranial tuberculoma.

In an attempt to establish a tuberculous etiology, polymerase chain reaction (PCR) and immunohistochemical (IHC) methods were undertaken in formalin-fixed paraffin sections of ten surgical specimens of intracranial tuberculoma. The control group included an equal number of intracranial fungal granuloma. Both PCR and IHC methods did not yield false-positive results in fungal granuloma. PCR was found to be less sensitive (60%) than IHC method (80%) in this study. IHC method definitely possesses several operational advantages over PCR and is more suited to laboratories in developing countries for establishing a tuberculous etiology particularly in those patients in whom the conventional bacteriological methods did not confirm the diagnosis of tuberculoma.

Significance of serum antibody to GD1b ganglioside in patients with Guillain-Barré syndrome.

BACKGROUND & OBJECTIVES: The precise etiological factors in Guillain-Barré syndrome (GBS) are still unknown. However, humoral and cellular immune factors may have a role in the pathogenesis of GBS. The present study was undertaken to evaluate the clinical significance of circulating serum IgG antibody to GD1b ganglioside in patients with GBS. METHODS: Serial samples of serum were collected from 18 patients with GBS undergoing plasma exchange (PE) during their hospital stay. Serum IgG antibody titers to GD1b, before, during as well as following PE were measured by an indirect enzyme-linked immunosorbent assay (ELISA). RESULTS: In 10 of 18 patients with GBS the antibody to GD1b was present in high titers (1:640-1:5120) prior to PE and the antibody titers in these 10 patients decreased following PE. At the time of completion of the study, the anti GD1b antibody titers declined in relation to clinical recovery in 7 of 10 patients with GBS. INTERPRETATION & CONCLUSION: The findings of the present study show that antibody to GD1b gangliosides may be one of the immunological factors in the pathogenesis of GBS and PE decreases the anti GD1b antibody titers in these patients.

A dot-immunobinding assay (dot-Iba) for rapid diagnosis of pulmonary tuberculosis.

IgG antibody to Mycobacterium tuberculosis from the sera of patients with 'definite' pulmonary tuberculosis (PT) was isolated and coupled with Cyanogen bromide-Sepharose 4B. Using an immunoabsorbent affinity chromatography, 14 kDa antigen was recovered from the culture filtrates of M. tuberculosis. With this mycobacterial antigen, a dot immunobinding assay (Dot-Iba) was developed for the detection of specific antibody to M. tuberculosis in the sera of patients with PT and controls. The assay gave positive results in all the 12 sputum-smear positive [acid fast bacilli (AFB)] patients with PT and gave negative results in the 50 sera from control groups. The Dot-Iba as described in this study, is simple, rapid and specific for laboratory diagnosis of PT.

Rapid diagnosis of tuberculous meningitis by a dot-immunobinding assay.

In this study, a dot-immunobinding assay (Dot-Iba) was standardized to measure circulating antimycobacterial antibodies in the cerebrospinal fluid (CSF) specimens for the rapid laboratory diagnosis of tuberculous meningitis (TBM). Specific CSF-IgG antibody to Mycobacterium tuberculosis from a culture proven patient with TBM was isolated and coupled with activated Cynogen bromide-Sepharose 4B. Using an immunoabsorbent affinity chromatography, 14 kDa antigen present in the culture filtrates of M. tuberculosis was isolated and this antigen was used in the Dot-Iba, to quantitate specific antimycobacterial antibodies in CSF specimens. The Dot-Iba gave positive results in all the 5 culture proven patients with TBM and gave no false positive results in CSFs from patients with partially treated pyogenic meningitis. Dot-Iba developed in our laboratory is a simple, rapid and specific method and more importantly suited for the routine application in laboratories with limited resources.

Rapid diagnosis of tuberculous meningitis by a dot immunobinding assay To detect mycobacterial antigen in cerebrospinal fluid specimens.

In the present prospective study, a dot immunobinding assay (Dot-Iba) was standardized to measure the circulating mycobacterial antigen in cerebrospinal fluid (CSF) specimens for the laboratory diagnosis of tuberculous meningitis (TBM). Immunoglobulin G antibody specific for Mycobacterium tuberculosis in a CSF specimen from a patient with culture-proven TBM was isolated and was coupled with activated cyanogen bromide-Sepharose 4B. By immunosorbent affinity chromatography, a 14-kDa antigen was isolated from the culture filtrate of M. tuberculosis. Antibody to the 14-kDa mycobacterial antigen was raised in rabbits. The Dot-Iba in this study gave no false-positive results with CSF specimens from patients with nontuberculous neurological diseases. The assay gave positive results for all five patients with culture-proven TBM. The Dot-Iba described in the present report is simple, rapid, sensitive, specific, and, more importantly, suitable for routine application in laboratories in developing countries.