An enzyme-linked immunoabsorbent assay for measuring antibodies against muscle acetylcholine receptor.

An enzyme-linked immunoabsorbent assay has been developed for measuring anti-acetylcholine receptor antibodies from sera of patients with myasthenia gravis or tissue culture supernatants from hybridomas. Acetylcholine receptor from a detergent extract of muscle tissue was bound indirectly to microtiter plates via a monoclonal anti-receptor antibody already coupled to the polyvinyl plates. Myasthenic sera or antibodies in tissue culture media were then tested for binding to the acetylcholine receptor attached to the monoclonal antibody. Anti-receptor antibodies were detected in the serum of 80% of myasthenic patients when assayed by this method and the levels of antibody corresponded fairly well with antibody titers determined by an immunoprecipitation assay. Occasional myasthenic patients had serum antibodies which reacted specifically with the monoclonal antibody attached to the microtiter plate. The assay described here was far less time-consuming than immunoprecipitation assays, required only small quantities of receptor, and did not require the use of radioisotopes such as 125I-alpha-bungarotoxin.

Transient diabetes insipidus following electrical burns in two patients.

We report on two healthy white men who sustained high-voltage electrical burns and were transferred to our regional burn center for specialized care. Within 24 hours of admission, both patients developed clinical signs and laboratory evidence of diabetes insipidus. With appropriate treatment, no sequelae occurred and their endocrinopathy spontaneously resolved. Diabetes insipidus following traumatic events is not uncommon; however, it has never been reported following an electrical injury.

Deer stands: a significant cause of injury and mortality.

Deer hunting is a popular recreational activity in the United States. Although the risks associated with firearms are well known, the hazards related to deer stands are not widely appreciated. From September 1982 through December 1989, there were 19 patients admitted to the Medical College of Georgia Hospital and Clinics for injuries sustained from falls related to deer stands. One death occurred, and six of the 18 survivors remain paralyzed. Data from 18 of these patients showed that 83% of these falls (15/18) were associated with hunter-constructed stands. Structural failure accounted for 39% (7/18) of the accidents; other causes included carelessness, falling asleep, and medical events. Four of the 19 patients (21%) had elevated blood alcohol levels on admission. Fracture of the spine and long bones accounted for the majority of the injuries, and seven of the 18 survivors (39%) were hospitalized for more than 4 weeks. Eight of the survivors (44%) remain permanently disabled. Deer-stand-related falls may result in significant long-term disability, expensive and lengthy hospitalization, and even death. A preventive approach to these injuries is paramount, and published guidelines for safety while hunting from deer stands should be followed.

Naturally occurring anti-idiotypic antibodies in myasthenia gravis patients.

Aberrant regulation of the immune system can lead to the development of autoimmune diseases such as myasthenia gravis. Autoantibodies against the nicotinic acetylcholine receptor (AChR) are found in the serum of myasthenia gravis patients and trigger a reduction of AChR at the muscle endplate resulting in increased muscle fatiguability. It is possible that the autoimmune response results from altered idiotype anti-idiotype network interactions. Here we have used a monoclonal anti-AChR antibody (ACR-24, gamma 1, kappa) in an enzyme-linked immunoabsorbent assay (ELISA) to measure anti-AChR immunoglobulin in human sera. In this assay, ACR-24 is attached to microtitre plates followed by the addition of solubilized human AChR which is bound by the immobilized ACR-24. However, during the development of this assay, it was observed that certain myasthenic patients appeared to have antibodies which bound to ACR-24 alone. This unexpected finding suggested that we had discovered naturally occurring anti-idiotype antibodies in myasthenic sera.