To analyze the frequency and clinical relevance of anti-Mi-2 autoantibody in a representative sample of patients with dermatomyositis. This longitudinal inception cohort study, from to , included 87 definite adult dermatomyositis. Anti-Mi-2 analysis was performed using a commercial kit. Seventeen patients The following parameters were equally distributed between the patients with versus without anti-Mi mean age at the disease diagnosis onset, median follow-up time, constitutional symptoms baseline , cutaneous cumulative lesions, dysphagia, joint and pulmonary involvement.
There was also no difference between the groups in relation to follow-up time, disease relapsing, treatment, disease status, deaths and occurrence of neoplasia. The anti-Mi-2 autoantibody was found in one fifth of patients with dermatomyositis.
This autoantibody was associated with a lower occurrence of pulmonary involvement, a higher frequency of disease in remission, and elevated levels of muscle enzymes. There was also no correlation regarding the frequency of disease relapsing or neoplasia development. Dermatomyositis DM is a systemic autoimmune myopathy that primarily affects the skin and skeletal striated muscle [ 1 , 2 , 3 , 4 , 5 ].
Several autoantibodies have been described in DM, which can be classified into myositis-specific or associated [ 2 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 ].
Among the myositis-specific autoantibodies, although there are controversies in the literature, anti-Mi-2 autoantibody has been correlated with the presence of cutaneous lesions [ 2 , 7 , 9 , 10 , 11 , 12 , 13 , 14 ], absence of pulmonary fibrosis [ 7 , 9 , 10 , 13 , 15 ], low risk of malignancy [ 7 , 9 , 13 , 14 , 15 ] and good disease outcome with glucocorticoid treatment [ 9 , 13 , 15 ].
