No abstract

The significance of immune reactions against peripheral nervous system antigens in the human inflammatory polyneuropathies is still uncertain. Using a very sensitive assay, we found greatly increased levels of anti-P2 antibodies in sera of animals with experimental allergic neuritis (EAN) but no increases in humans with acute Guillain-Barré syndrome (GBS), chronic relapsing polyneuritis (CRIP), axonal neuropathy, or normals. P2 protein and CNS basic protein did not induce any increased proliferation in lymphocytes of GBS or CRIP patients. We conclude that P2 and BP appear unlikely to be targets for humoral or cellular immune reactivity in GBS or CRIP.

No abstract

We studied secretion of immunoglobulin (Ig) by freshly isolated and pokeweed mitogen (PWM)-stimulated thymus cells and blood mononuclear cells in patients with myasthenia gravis (MG) and control subjects undergoing elective cardiac surgery. We used a protein A reverse hemolytic plaque assay to enumerate cells secreting IgG, IgM, and IgA (IgSC), and an ELISA assay for measuring IgG secreted into culture supernatants. We found that freshly isolated suspensions of MG thymus cells, compared with control thymus cells, contained increased numbers of cells that spontaneously secreted immunoglobulin. Thymus mononuclear cells from control as well as MG patients appeared capable of B-cell differentiation responses when stimulated by PWM. PWM-induced responses were greater in thymic than in autologous blood mononuclear cells in some MG patients and controls, although B cells were much less frequent in suspensions of thymic cells than blood cells. Thus, the thymus provides a favorable milieu for differentiation of its few B cells. In MG, the thymus may be a site of accentuated in vivo B-cell activation, as evidenced by increased numbers of resident IgSC.

We studied the in vitro synthesis of antibodies to acetylcholine receptor (anti-AChR) by peripheral blood mononuclear cells (PBM) of patients with myasthenia gravis (MG) and normal subjects (NS). PBM from three of eight patients with generalized MG (MG-G) synthesized anti-AChR in vitro in the absence of pokeweed mitogen (PWM), and seven of eight did so in the presence of PWM. In individual subjects with MG-G, the levels of anti-AChR secreted in vitro by PBM correlated with serum anti-AChR antibody levels (r = 0.77) but not with the amount of IgG secreted in vitro (r = 0.44). No anti-AChR secretion was seen in culture of PBM from a patient with ocular MG, a patient with thymoma without MG, or six NS.