Myasthenia gravis is an autoimmune disease which results from antibodies that block acetylcholine receptors at the neuromuscular junction. This prevents nerve impulses from triggering muscle contractions. The most commonly affected muscles are those of the eyes, face, and swallowing. It can result in double vision, dropping eye leads, trouble talking, and trouble walking. Diagnosis can be supported by blood tests for specific antibodies, the edrophonium test, or nerve conduction studies.
The anti–acetylcholine receptor antibody test is reliable for diagnosing autoimmune myasthenia gravis. It is highly specific as high as 100%. Results are positive in as many as 90% of patients who have generalized MG but in only 50-70% …show more content…
Each titer involves doubling the amount of test fluid, so that the difference between a titer of 1:640 and 1:320 is one dilution. The titers may increase and decrease over the course of the disease; these fluctuations do not necessarily correlate with disease activity. Thus, it is not useful to follow the ANA test in someone already diagnosed with lupus
Rheumatoid arthritis
Rheumatoid Arthritis is a systemic disease, accompanied by progressive joint destruction and deformity. Depending on the severity, there may also be extra-articular manifestations, with involvement of the skin, blood vessels, eyes, lungs, heart, nerves, and internal organs. If inadequately treated, RA leads in the long term to a significant impairment of the quality of life; morbidity and mortality increase. The symmetric multiple joint involvement helps distinguish rheumatoid arthritis from other types of arthritis.
While diagnosis of RA relies heavily on the clinical picture, some of the signs and symptoms may not be present or follow a typical pattern, especially early in the disease. Furthermore, the signs and symptoms may not always be clearly identifiable since people with RA may also have other connective tissue disorders or