Multiple sclerosis and human T-cell lymphotropic retroviruses: negative serological results in 135 German patients

Specificity of intrathecal IgG synthesis for HTLV-1 core and envelope proteins in HAM/TSP

INTRODUCTION

In patients with human T-cell lymphotropic virus type 1 (HTLV-1) associated myelopathy/tropical spastic paraparesis (HAM/TSP), we investigated the significance of HTLV-1 specific antibodies in the cerebrospinal fluid (CSF).

MATERIAL AND METHODS

The quantities of HTLV-1 specific immunoglobulin G (IgG) in paired CSF and serum were evaluated by a sensitive enzyme immunoassay (EIA). The specificity of antiviral IgG was determined by radioimmunoprecipitation of HTLV-1 antigens.

RESULTS

In 17 of 20 HAM/TSP patients, quantitative evaluation by EIA supplied evidence for antiviral IgG synthesis within the CNS. Radioimmunoprecipitation demonstrated IgG antibodies against HTLV-1 envelope and core proteins in all HAM/TSP CSF and sera tested. Regarding the 3 sample pairs indeterminate in EIA for intrathecal synthesis, 2 showed stronger precipitation of HTLV-1 antigens by CSF IgG than by equal amounts of serum IgG.

CONCLUSION

Intrathecal antibody synthesis specific for both HTLV-1 core and envelope antigens is common in HAM/TSP, thus providing conclusive evidence for an immune response to HTLV-1 within the CNS.

A soluble form of tumour necrosis factor receptor in cerebrospinal fluid and serum of HTLV-I-associated myelopathy and other neurological diseases

Paired samples of cerebrospinal fluid (CSF) and serum from 17 patients with human T-cell lymphotrophic virus I (HTLV-I)-associated myelopathy, 5 patients with multiple sclerosis and 11 controls with non-inflammatory disorders (migraine, idiopathic epilepsy and myelopathy of unknown aetiology) were examined by enzyme-linked immunosorbent assay for the presence of the 60-kDa soluble form of tumour necrosis factor receptor (sTNF-R). The results were compared with blood-CSF barrier function, cell count and the intrathecal synthesis of HTLV-I antibodies. No correlation could be demonstrated. High levels of sTNF-R were found in CSF of patients with HTLV-I-associated myelopathy and multiple sclerosis. In addition, intrathecal sTNF-R was also detected in the patients with non-inflammatory diseases, indicating that sTNF-R is definitively a normal constituent of CSF.

Differential diagnosis of HTLV-I-associated myelopathy and multiple sclerosis in Iranian patients

Two Iranian patients with chronic progressive spastic paraparesis and urinary dysfunction were referred to our hospital with the presumptive diagnosis of multiple sclerosis (MS). Routine CSF analysis and magnetic resonance imaging of the two patients were only partially characteristic of MS. Testing for antibodies to human T-cell leukemia virus type I [HTLV-I] in serum using a radioimmune precipitation assay revealed antibodies to HTLV-I in both patients. The infection with HTLV-I was confirmed by polymerase chain reaction (PCR) and liquid hybridization analysis using primers to the tax/rex region and a corresponding probe, demonstrating proviral DNA in peripheral blood mononuclear cells of both patients. On the basis of these findings demonstrating the presence of proviral HTLV-I DNA in the two Iranian patients, the initial diagnosis of MS was corrected to that of HTLV-I-associated myelopathy (HAM). In contrast, several patients with definite MS (nine from Germany, two from Iran) with a relapsing and remitting form of the disease were tested for HTLV-I infection by enzyme-linked immunosorbent assay and PCR, which yielded negative results. However, the mother of one HAM patient was found to be infected with HTLV-I. To support an association between HTLV-I infection and CNS disease in the two HAM patients, we analyzed the production of specific IgG antibodies within the CNS based on a simple enzyme immunoassay for viral IgG antibodies in CSF and serum. In the two HAM patients there was significant intrathecal antibody production directed against HTLV-I, but this was not found in any of the samples from MS patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Human T-cell lymphotropic virus type I sequences detected by nested polymerase chain reactions are not associated with multiple sclerosis

The hypothesis that human T-cell lymphotropic virus type I (HTLV-I) infection is associated with multiple sclerosis (MS) was tested by using primers specific to gag and pol regions of HTLV-I in an analysis that used polymerase chain reactions. No amplification of DNA from patients with MS was detected with primers for either region. After application of a more sensitive scheme with use of nested primers, however, half the samples, including patients with MS and normal control subjects, were found to contain pol DNA sequences. No sequences related to the HTLV-I gag region were detected among patients with MS by using nested primers. Sequences of the amplified HTLV-I pol genomes were determined. Regardless of their origin (MS or normal control), the pol region sequences were similar to HTLV-I sequences reported by other investigators. We conclude that HTLV-I does not have a distinct association with MS, but HTLV-I-related sequences, although in extremely low copy number, may be present in human genomes.

Low-titer antibodies reactive with HTLV-I gag p19 in patients with chronic myeloneuropathy

To elucidate the possible association of human T-lymphotropic virus type I (HTLV-I) and chronic neurological diseases, 156 serum samples from patients with various neurological diseases, including multiple sclerosis, chronic progressive myelopathy, chronic inflammatory polyradiculoneuropathy, myasthenia gravis, polymyositis, motor neuron disease, and tension headache, and healthy control subjects were examined for IgG antibodies to HTLV-I by three independent techniques--gelatin particle agglutination test, enzyme-linked immunosorbent assay, and Western blot assay. Specificity of antibodies was assessed by homologous competitive inhibition on Western blot assay. Six patients (3 with chronic progressive myelopathy, 1 with chronic inflammatory polyradiculoneuropathy, 1 with motor neuron disease, and 1 with tension headache) had high-titer HTLV-I antibodies. Twelve patients (5 with multiple sclerosis, 1 with chronic progressive myelopathy, 2 with chronic inflammatory polyradiculoneuropathy, 2 with myasthenia gravis, and 2 with motor neuron disease) had low-titer HTLV-I antibodies that reacted with a single gag protein, p19 or p24, on Western blot assay. In 4 (2 with multiple sclerosis, 1 with chronic progressive myelopathy, and 1 with chronic inflammatory polyradiculoneuropathy) of these 12, the antibodies that were all directed to p19 were determined to be specific by homologous competitive inhibition. In the remaining 8 patients (3 with multiple sclerosis, 1 with chronic inflammatory polyradiculoneuropathy, 2 with myasthenia gravis, and 2 with motor neuron disease), restricted reactions against p19 or p24 were considered to be nonspecific because they were not inhibited by homologous competitive inhibition. The results suggest that in some patients chronic myeloneuropathy diagnosed as chronic progressive multiple sclerosis, chronic progressive myelopathy, and chronic inflammatory polyradiculoneuropathy may be associated with HTLV-I or related retroviruses.

Antibodies in sera from Norwegian multiple sclerosis patients and the general population reacting with HTLV-1. A pilot study

By using enzyme-linked immunosorbent assay, Western blot and passive agglutination we have performed a pilot study involving the testing of 349 sera from the general population of 3 coastal regions in southern Norway, 230 sera from multiple sclerosis patients from western Norway, 109 age- and sex-matched controls and 34 sera from patients with other neurological diseases, for antibodies to HTLV-I. About 2% and 4% of sera from the general population had antibodies reacting with HTLV-I in ELISA and Adult T-cell Leukemia Antigen by agglutination, respectively, whereas about 8% and 5% of the multiple sclerosis sera had such antibodies. In the general population antibodies were more frequent among young individuals and there appeared to be some prevalent regional differences. Western blot confirmatory tests showed that in some instances antibodies reacted with the gag proteins, in particular p19. The results obtained in this study do not indicate an association between HTLV-I and multiple sclerosis, although at this stage we cannot rule out that another retrovirus is involved.