BACKGROUND: A human B-cell subpopulation which is identifiable by the expression of cell surface antigen Leu-1 (CD5) is known to be responsive for the antoantibody secretion. The exprimental autoimmune myasthenia gravis(EAMG) could be induced in animals by injecting AChR from electric eel and had the same clinical and pathophysiological characteristics with human myasthenia gravis(MG). The authors performed the study to compare the frequncy of CD5 positive B-lymphocytes in EAMGs with those in human MGs and to understand whether the EAMG showed the similar immunological feature as in human MG. METHOD: For EAMG the 50ug AChR from Torpedo Marmorata with Freund's adjuvant were injected to Lewis rats of 150-200mg three times. The CD5 positive B-lymphocytes from peripheral blood were double stained by the monoclonal PE conjugated anti-CD5 and FITC conjugated anti-rat CD45 antibodies in the EAMGs and by the PE conjugated ani-Leu-11(CD5) and FITC conjugated anti-human Leu-12(CD19) antibodies in human MGs. The expression of positive CD5 positive B-lymphocytes were calculated by the fluorescent activated cell sorter(FACS). RESULTS: The mean CD5 positive B-lymphocytes expression in four EAMGs was 15.05% with ranging from 10.2% to 20,0%, which was increased compared with those in control rats. The mean frequency of CD5 positive B-lymphocytes were 25.2+/-15.05% in human MG(N=25) and 16.0+/-13.5% in normal controls (N=20) respectively, which did not show any significant difference (P=0.08). However the expression of CD5 positive B-lymphocytes in human MGs was significantly correlated with the titer of anti-AChR antibody (P=0.04). CONCLUSION: The increased expression of CD5 positive B-lymphocytes might be associated with the EAMG pathomechansms, but their expression only showed possible correlation with the anti-AchR antibody titer with minimal role in pathogenetic process of human MG. Therefore it would be suggested that immunological process of EAMG (acute form of MG) be a little different from that of human MG, chronic form.
Animals ; Antibodies ; Antigens, Surface ; B-Lymphocytes* ; Electrophorus ; Fluorescein-5-isothiocyanate ; Freund's Adjuvant ; Humans* ; Myasthenia Gravis* ; Rats ; Torpedo

Since Willis described 'fatigable weakness' in 1672, most physicians consider it as a kind of hysteria due to the inconsistent fluctuation of symptoms. Erb presented three cases of 'bulbal palsy' in the 1870s, and Oppenheim and Hopper considered myasthenia gravis as a disease similar to curare poisoning and as a disease induced by attack of the motor centers by intrinsic toxins, respectively. In 1903, Elliot suggested that a 'chemical substance' mediates the nerve impulses at synapse. However, it was not until 1921 that this was demonstrated by Loewi, who provided evidence from the famous two-frog-hearts experiment. Dale later revealed the substance to be acetylcholine, and he also suggested that myasthenia gravis is due to a problem with the motor end plate. In 1934, Walker was prompted by the resemblance between myasthenia gravis and curare poisoning to apply physostigmine, a curare-poisoning antidote, to a patient, which produced a dramatic result. Since then the use of anticholinesterase inhibitors has been adopted for standard therapeutic modality. Some prominent surgeons have also applied thymectomy as a surgical modality. The most recent focus of myasthenia gravis has been immunological. In 1960, Simpson proposed the autoimmune hypothesis, and Chang et al. showed that snake venom contained a selective antagonist of the nicotinic acetylcholine receptor, alpha-bungarotoxin. The immunization of rabbits with acetylcholine receptor purified from the electrical organs of electric eels by Patrick et al. induced myasthenic symptoms and signs, and these were reversed by acetylcholinesterase inhibitors. The role of the autoimmune system has led to the introduction of an immunosuppressive modality and plasma exchange to the field of clinical neurology.
Acetylcholine ; Action Potentials ; Bungarotoxins ; Cholinesterase Inhibitors ; Curare ; Electrophorus ; History of Medicine ; Humans ; Hysteria ; Immunization ; Motor Endplate ; Myasthenia Gravis ; Physostigmine ; Plasma Exchange ; Rabbits ; Receptors, Nicotinic ; Snake Venoms ; Synapses ; Thymectomy