Ikuo Kinoshita

Plasmapheresis in treatment of human T-lymphotropic virus type-I associated myelopathy.

In 11 of 18 patients with human T-lymphotropic virus type-I (HTLV-I) associated myelopathy (HAM) gait, sensory, and/or sphincter disturbance improved with plasmapheresis (4 to 6 sessions in 2 weeks), and the effects were maintained for 2 to 4 weeks. Plasmapheresis lowered the titre of HTLV-I antibody in serum but not in cerebrospinal fluid, and change of HTLV-I antibody titres did not correlate with the effects of plasmapheresis. These results suggest that plasmapheresis is useful treatment, at least in producing a temporary improvement, in patients with HAM, and that some humoral factor(s), but not HTLV-I antibody, may be important in the pathogenesis of HAM.

Increased granzyme B mRNA after alloincompatible myoblast transplantation.

Normal C57BL/10SnJ myoblasts were transplanted into the tibialis anterior of C57BL/10SnJ, C57BL/ScSn mdx, or BALB/c mice. These transplantations allowed us to investigate the immune response not only against MHC but also against dystrophin introduced in the dystrophic muscles by such transplantations. Recently, our group reported following myoblast transplantations cellular infiltration of the host muscle by class II MHC cells, macrophages, and lymphocytes expressing CD4 or CD8 and IL-2 receptors. In the present study, activation of these infiltrating lymphocytes was investigated by measuring the expression of granzyme B mRNA. We used reverse-transcriptase polymerase chain reaction to detect granzyme B mRNA at various intervals after myoblast transplantations. To standardize the results, the mRNA were reverse transcribed using an oligo (dt) so that beta-actin mRNA could also be amplified from the same cDNA preparation. Granzyme B mRNA was increased for at least 3 weeks after MHC alloincompatible grafts. The absence of increased granzyme B expression after allocompatible transplantation in mdx mice suggests that dystrophin is not sufficiently immunogenic to induce short term acute rejection. These results indicate that lymphocytes infiltrated in muscles injected with histoincompatible myoblasts are activated and sustain the requirement for an adequate immunosuppression after such transplantations.

Mechanism of increasing dystrophin-positive myofibers by myoblast transplantation: study using mdx/β-galactosidase transgenic mice

Abstract Female mdx/mdx mice were crossed with non-dystrophic transgenic males expressing the β-galactosidase (β-gal) gene under a muscle-specific promoter (TnILacZ1/29). All male offspring were mdx mice and about 50% of them also expressed the β-gal gene. The β-gal/mdx mice were selected as recipients for the transplantation of myoblasts from non-transgenic normal BALB/c mice. When host muscles were not irradiated before myoblast transplantation, 4.6% of the muscle fibers in host muscles were dystrophin positive 1 month after transplantation. Most of these dystrophin-positive muscle fibers were also β-gal positive. About one quarter of these fibers are the result of reverse mutations; most of them have, however, been produced by fusion of donor myoblasts with host muscle fibers or with host myoblasts. The virtual absence of β-gal-negative fibers indicates that there were no exclusively donor-donor fusions. When host muscles were irradiated before myoblast transplantation, roughly the same percentage (5.5%) of dystrophin-positive fibers were formed in the injected muscle, but 42% of them were β-gal negative. These β-gal-negative dystrophin-positive muscle fibers were formed by the exclusive fusion of donor myoblasts with one another rather than with host cells. This clearly indicates that myoblast transplantation can form completely new muscle fibers or muscle fiber segments when host satellite cell proliferation is reduced by irradiation. These newly formed muscle fibers had, however, a small diameter and additional myoblast transplantation may be required to increase their size. This situation has some similarities with findings in Duchenne muscular dystrophy patients of more than 6 years of age, who also have a limited proliferation capacity of their satellite cells.

Vascular cell adhesion molecule-1-mediated matrix metalloproteinase-2 induction in peripheral blood T cells is up-regulated in patients with HTLV-I-associated myelopathy.

We investigated whether matrix metalloproteinase-2 (MMP-2) is induced in peripheral blood T cells after their contact with tumor necrosis factor-alpha (TNF-alpha)-stimulated glioblastoma cell line (T98G), expressing vascular cell adhesion molecule-1 (VCAM-1), in patients with HTLV-I-associated myelopathy (HAM) compared to control patients with other neurological disorders (OND). Gelatin zymography revealed that the incremental ratio of gelatinolytic activity of MMP-2 in culture supernatants derived from T cells cocultured with TNF-alpha-stimulated T98G to that of supernatants derived from cultures of T cells alone was significantly higher in HAM patients than in control patients with OND. Immunoblot analysis of immunoprecipitates of culture supernatant showed that increased gelatinolytic activity of MMP-2 was due to increased production of MMP-2 protein in T cells. Increased gelatinolytic activity of MMP-2 in T cells of HAM patients was blocked by pretreatment of TNF-alpha-stimulated T98G with anti-VCAM-1 antibody before coculture with T cells, indicating that MMP-2 induction was VCAM-1-mediated. Although no significant differences were noted in the percentage of VLA-4-positive cells in cultured T cells between HAM patients and control patients with OND, our results indicate that VCAM-1-mediated MMP-2 induction is up-regulated in T cells of HAM patients.

Role of the macrophage in the pathogenesis of experimental autoimmune myasthenia gravis

To clarify the role of Ia antigen positive macrophages which invade motor end-plates in the induction of the chronic phase, experimental autoimmune myasthenia gravis (EAMG) rats were injected intraperitoneally with silica dust on day 6 after immunization. Silica injection partially inhibited the invasion of motor end-plates with macrophages as compared with a saline injection. The titer of antibodies to the Narke acetylcholine receptor (AChR) in the chronic phase did not differ in either the saline or the silica groups, while the titer of antibodies to rat-AChR (non-crossreactive antibodies) was lower in the silica group than in the saline group. The silica group survived longer than the saline group. These results suggest that Ia antigen positive macrophages in the acute phase act as antigen-presenting cells and play an important role in the production of antibodies to self-AChR in the chronic phase.

Efficacy of prosultiamine treatment in patients with human T lymphotropic virus type I-associated myelopathy/tropical spastic paraparesis: results from an open-label clinical trial

BackgroundHuman T lymphotropic virus type I (HTLV-I)-associated myelopathy/tropical spastic paraparesis (HAM/TSP) is a chronic myelopathy characterized by motor dysfunction of the lower extremities and urinary disturbance. Immunomodulatory treatments are the main strategy for HAM/TSP, but several issues are associated with long-term treatment. We conducted a clinical trial with prosultiamine (which has apoptotic activity against HTLV-I-infected cells) as a novel therapy in HAM/TSP patients.MethodsWe enrolled 24 HAM/TSP patients in this open-label clinical trial. Prosultiamine (300 mg, orally) was administered once daily for 12 weeks. We monitored changes in the motor function of the lower extremities and urinary function as well as copy numbers of the HTLV-I provirus in peripheral blood mononuclear cells (PBMCs).ResultsImprovement in the motor function of the lower extremities based on a reduction in spasticity (for example, decrease in time required for walking and descending a flight of stairs) was observed. In an urodynamic study (UDS), bladder capacity and detrusor pressure and then maximum flow rate increased significantly. Detrusor overactivity and detrusor-sphincter dyssynergia improved in 68.8% and 45.5% of patients observed at pretreatment, respectively. Improvement in UDS corresponded with improvements in the score of nocturia-quality of life questionnaire. HTLV-I proviral copy numbers in PBMCs decreased significantly (approximately 15.4%) compared with pretreatment levels.ConclusionsThese data suggest that prosultiamine can safely improve motor dysfunction of the lower extremities and urinary disturbance as well as reduce HTLV-I provirus levels in peripheral blood. It therefore has potential as a new therapeutic tool for HAM/TSP patients.Trial registrationUniversity Hospital Medical Information Network Clinical Trials Registry (UMIN-CTR) number, UMIN000005969.Please see related commentary: http://www.biomedcentral.com/1741-7015/11/183.

Central motor conduction time in patients with HTLV-1 associated myelopathy

ABSTRACT— Transcranial electrical stimulation of the motor cortex was performed in 7 patients with human T‐lymphotropic virus type‐I associated myelopathy (HAM) and 15 normal subjects. The mean value of central motor conduction time (CCT) for the thenar and hypothenar muscles in patients with HAM was not different from that in normal subjects. In contrast, mean CCT value for the tibialis anterior and gastrocnemius muscles in patients with HAM was 8.54‐10.34 ms longer than the value in normal subjects. These findings indicate that the lesion of pyramidal tract involvement in patients with HAM is mainly localized in the descending corticomotoneuron pathways at the thoracic spinal cord level. This technique could be used in a clinical study without untoward side effects, and may be valuable in detecting clinically silent lesions involving the pyramidal tract.

Myasthenia gravis with diffuse alopecia areata and pemphigus foliaceus

Sirs: Myasthenia gravis (MG) is an autoimmune disease of neuromuscular transmission associated with antibodies to acetylcholine receptors (AChR) [1]. MG can be accompanied by skin disorders, including pemphigus, vitiligo, and alopecia areata [2–6], which may be immunological diseases. Although the association of pemphigus or alopecia areata with MG is well documented, there have been no reports of the direct association of the three diseases. We report here a case of MG with thymoma associated with alopecia areata and pemphigus foliaceus. The patient was a 49-year-old woman who developed hair loss from November 1997 and spontaneous fugitive right blepharoptosis from February 1998. In March 1998, erythema with itching appeared on soma and a mediastinal tumor was incidentally found on chest radiography. She was admitted to our hospital in May 1998, and on admission, physical examination showed right blepharopsosis and muscle weakness after repetitive movement. Ocular movement was full and there was no diplopia. Multiple incomplete circles of alopecia were noted over her entire scalp, and annular, vesicular and erythematous plaques were noted on the trunk and limbs (Fig. 1). Her blood cell count was normal, and a biochemical examination showed only a slight elevation of transaminase. The anti-AChR antibody concentration was positive (19 nMol/L). The thyroid function was normal. The Tensilon test was positive to an improvement of blephaloptosis and electrophysiologic studies showed a decremental evoked response (10 %) for the trapezius (3Hz repetitive stimulation). Computed tomography of the chest revealed a 5cm septum mediastinal tumor. Muscle biopsy of the left biceps branchii revealed characteristics of MG [7]; immune complexes (IgG, C3) at the motor endplates, and simplified primary and secondary synaptic folds by ultrastructural study. Skin biopsy specimen of the scalp revealed hair follicles showing fibrous change with lymphocytic infiltration. Microscopic examinations of the skin biopsy specimen from the trunk revealed the picture of pemphigus; intraepidermal blisters containing many eosinophils and direct immunofluorescence showed intercellular epidermal staining for IgG and C3 (Fig. 1). And, antibodies to desmoglein 1, which is an autoantigen for pemphigus foliaceus, was detected in serum by enzymelinked immunosorbent assay. But that to desmoglein 3, which is autoantigen for pemphigus vulgaris, was not detected. Thymectomy was performed and the histopathology of the thymus indicated a thymoma. Postoperatively, the myasthenic symptoms and skin disorders improved and were well controlled by steroid therapy. In this patient, based on the clinical features and examinations including skin biopsy and detection of some antibodies, we made a diagnosis of generalized MG with thymoma, alopecia areata and pemphigus foliaceus. It is well known that various autoimmune LETTER TO THE EDITORS

Myasthenia gravis associated with limited scleroderma (CREST syndrome)

Sirs: Myasthenia gravis (MG) is an autoimmune disease associated with antibodies to acetylcholine receptors (AChR). Although MG and scleroderma are associated with other autoimmune diseases [1], direct association between the two diseases is rare [2–4]. CREST syndrome, a variant of systemic sclerosis is characterized by the presence of calcinosis, Raynaud’s phenomenon, esophageal mobility abnormalities, sclerodactyly, teleangiectasia, and positivity to anti-centromere antibodies [5]. Its clinical course is considered to differ from that of systemic sclerosis because of the development of clinical features late in life and the better prognosis. We report another case of MG that developed in a patient 3 years after the onset of CREST syndrome, the first report in English of MG and CREST syndrome in the same patient. A Japanese woman with no family history of neuroimmunological disease first visited our hospital because of mild liver dysfunction that appeared at age 50 years. No clear etiology, however, could be determined. At age 52 she noticed that her hands became cold and white when washing dishes in cold water, and the skin on her fingers felt tight. At age 53 she was told that the anticentromere antibody test was positive, but she refused further examinations. At age 56 she experienced limb fatigue on mild effort and bilateral ptosis in the evening. She had slight difficulty in swallowing, and her mouth was always dry. A month later, after being told that on continued speaking her speech tended to become unclear, she was admitted to our hospital. Physical examination showed bilateral ptosis and muscle weakness after repetitive movement. Ocular movement was full, and there was no diplopia. Dysarthria and rhinolalia were very obvious after only a few minutes of speech. The skin of her hands felt tight and thick, and on exposure to cold water the hands became very white and cold (Fig.1). Neither teleangiectasia nor hepatosplenomegaly were present. Her blood cell count was normal. Biochemical examination showed mild liver dysfunction (elevated alkaline phosphatase and γ-glutamyl transpeptidase). The anti-AChR antibody concentration was 20 nmol/l (normal: lower than 0.5 nmol/l), and anti-skeletal muscle antibody was positive at titer of 1 :160. Moreover, the anti-centromere antibody was LETTER TO THE EDITORS J Neurol (2000) 247 :61–62

胸腺腫大をともなう抗signal recognition particle抗体陽性ミオパチーの1例

A 54-year-old female was admitted to our hospital because of the Raynaud phenomenon and muscle weakness of the upper limbs. The neurological findings showed somatic and proximal limb weakness. Laboratory studies showed a high serum creatine kinase level. Computerized tomography (CT) revealed enlargement of the thymus. A muscle biopsy showed a small number of degenerating and regenerating fibers but no inflammatory infiltrations. At first, she was initially treated with a three-day course of intravenous methylprednisolone (1 g/day). However, the weakness progressed and the serum creatine kinase level remained high. She was subsequently treated with a combination of tacrolimus (3 mg/day) and prednisolone, but showed no any improvement of the muscle weakness. Following additional treatment with intravenous immunoglobulin, she showed improvement in her muscle weakness. Further, anti-signal recognition particle antibodies were identified after treatment. There have been no previous reports of myopathy with antibodies against the signal recognition particle and enlargement of the thymus, so we herein report the details of this unique case.