N-CAM Expression: The Study of Muscle Disease in a Tertiary Center of Thailand

Abstract

Background: Neural cell adhesion molecule (N-CAM), or CD56, is a cell-surface glycoprotein that plays a critical role in mediating intercellular adhesion in the central nervous system. It is also found to be expressed on embryonic muscle but disappears in healthy adult muscle. However, denervated or regenerating muscles can express N-CAM. Objective: To evaluate the value of N-CAM expressions in diagnosing muscle diseases in the Thai population. Materials and Methods: The present study used immunohistochemistry to interpret N-CAM expression in 75 muscle biopsy specimens diagnosed with myopathies and non-myopathies from a 3-year retrospective cohort. Results: Using the chi-squared test, there was statistically significant associativity between N-CAM expression and the diagnosis of inflammatory myopathy, but not in muscular dystrophy, neurogenic change, or non-specific myopathy even though they also showed N-CAM expression. The inflammatory myopathy showed positive N-CAM in 15 out of 17 cases with statistical significance (p<0.001, OR 14.250, 95% CI 2.960 to 68.606). The authors did not find any N-CAM expression in the present study mitochondrial myopathy or non-myopathy cases, whose biopsies were defined as a control group due to lack of myopathic change and non-specific clinical symptoms. Conclusion: The authors suggest the evaluation of N-CAM expression as a complementary tool in the diagnosis of muscle diseases that have denervated or regenerating muscle fibers, especially in inflammatory myopathy. Keywords: Neural cell adhesion molecule; N-CAM; CD56; Muscle disease; Myopathy