OBJECTIVES:
To evaluate serum levels of C-reactive protein and erythrocyte sedimentation rates in patients with untreated newly diagnosed dermatomyositis or polymyositis and their correlation with clinical and laboratory parameters.
METHODS:
A cross-sectional study including 48 consecutive patients with untreated newly diagnosed dermatomyositis and polymyositis reviewed between 2002 and 2015 was conducted. Fifty healthy subjects were enrolled as controls.
RESULTS:
Patients with dermatomyositis and polymyositis had higher levels of C-reactive protein and erythrocyte sedimentation rate than healthy controls, but these values were not associated with clinical or laboratory parameters of disease activity either for dermatomyositis or for polymyositis. Additionally, erythrocyte sedimentation rate values correlated with pulmonary involvement as evidenced through computer tomography imaging (OR 1.15; 95%CI 1.01-1.31) only in patients with polymyositis.
CONCLUSIONS:
Although elevated, C-reactive protein and erythrocyte sedimentation rate are not sensitive parameters for measuring clinical and laboratory activity of dermatomyositis nor for polymiositis. However, erythrocyte sedimentation rate may be a valid parameter for screening pulmonary involvement, particularly in patients with polymyositis.
KEYWORDS:
Dermatomyositis; polymyositis; C-reactive protein; erythrocyte sedimentation rate