The results of a multicentre trial were analysed to evaluate the efficacy of immunoadsorption therapy for severe generalised myasthenia gravis. Twenty patients with myasthenia gravis who were concurrently receiving high dose prednisolone and azathioprine therapy were treated with an affinity-type adsorbent, using tryptophan-linked polyvinyl alcohol gel (IM-TR), according to a standardised treatment protocol. The 20 patients received five adsorption treatments within a period of 10 days. In 11, pronounced improvement of myasthenic weakness was seen and long-term remission was maintained. The treatment was especially effective in patients with thymic hyperplasia. Circulating acetylcholine receptor (AChR) antibodies were reduced by about 60% by treating one plasma volume. There was no difference in the rate of removal of the AChR antibodies between patients with thymic hyperplasia and patients with thymoma.

Plasmapheresis not only removes humoral factors, but may also modulate cellular immunity. We investigated whether plasmapheresis influenced T helper type-1/T helper type-2 (Th1/Th2) cytokine-producing-cell balance in 3 patients with neuroimmunological disease. The production of interferon-␥ (IFN-␥), interleukin-2 (IL-2), and IL-4 in the culture supernatant of peripheral blood mononuclear cells stimulated by anti-CD3 and anti-CD28 was assayed. In 2 of 3 patients, plasmapheresis (immunoadsorption or plasma exchange) reduced Th1/Th2 cytokine ratio. The results may suggest that plasmapheresis induces a shift of Th1/Th2 balance in peripheral blood.

The pathogenesis and underlying lesion of acquired idiopathic generalized anhidrosis (AIGA) are apparently heterogeneous. We report a patient with AIGA in whom the eccrine glands were histologically normal. However, electron microscopic examination showed markedly low numbers of nerve terminals and unmyelinated axons associated with the eccrine glands. Our laboratory investigations suggest that degeneration of postganglionic sympathetic cholinergic nerve may be the underlying pathogenetic mechanism of anhidrosis in this patient.

Because myasthenia gravis (MG) is an autoimmune disease mediated by Abs specific for the acetylcholine receptor, helper T cells play a role in Ab production. In this study, we have performed large-scale cross-sectional and longitudinal TCR studies by CDR3 spectratyping using PBL and thymus tissues from MG patients. We found that there was no preferential usage of any particular TCR β-chains that was identical among MG patients. However, the longitudinal study clearly demonstrated that one or more TCR Vβ expansions persisted frequently in MG patients. Importantly, persistent TCR expansions correlated with clinical severity and high anti-acetylcholine receptor Ab titer. Finally, examinations of T cells expressing CXCR5, i.e., follicular B-helper T cells, revealed that spectratype expansions in MG patients were detected mainly in the CD4+ CXCR5+ T cell populations, whereas CD8+ T cells were the major source of clonal expansion in healthy subjects. These findings suggest that persistent clonal expansions of T cells in MG patients are associated with the development and maintenance of MG. Close examination of pathogenic T cells in MG provides useful information to elucidate the pathogenesis and to estimate the disease status.