Acetylcholine hapten

A major application of monoclonal antibodies is in clinical assays for drugs, bacterial and viral products, tumor antigens, hormones, and other circulating proteins. Their use in conjunction with immunoassays (Box 31-C) has provided increased specificity and sensitivity. Another major application is to observe binding of antibodies to specific proteins by electron microscopy. The location of specific receptor proteins can be established - as can the locations of ribosomal proteins and many other cellular components (Fig. 29-1). Monoclonal antibodies to acetylcholine receptors have been shown to induce symptoms of myasthenia gravis (Box 31-D), supporting the autoimmune origin of that disease. 1 Monoclonal antibodies specific for such a small hapten as mercuric ion have been isolated.k... 

If suxamethonium acted as a bivalent allergen, it would be expected that acetylcholine would behave at least as a weak hapten, and that it would inhibit the response (histamine release) to suxamethonium. Figure 5 shows the result of adding acetylcholine to suxamethonium. In this experiment, a low concentration of acetylcholine (5 pg/ml) completely inhibited suxamethonium-induced histamine release from the leucocytes of a patient. It should be added that the specificity of inhibition by acetylcholine was confirmed by the lack of an inhibitory effect of acetylcholine on histamine release from human leucocytes induced by other allergens. 

---