We have noted that values for serum creatine phosphokinase (CPK) are frequently low in patients with connective tissue diseases. Geometric mean values were 96.0 units/L among 121 disease-free males and 50.2 units/L among 63 disease-free females. The geometric mean values were 31.7 units/L in 11 males and 35.2 units/L in 49 females with systemic lupus erythematosus; 15.1 units/L in three males and 13.0 units/L in ten females with rheumatoid arthritis; and 41.6 units/L in 19 females with Sjögren's syndrome. Values within the normal range may occur in the face of active myositis in these illnesses. Findings of a low serum CPK value may occur in the absence of steroid treatment. Thus, a low serum CPK value is frequently found in patients with connective tissue diseases and a normal value should not dissuade one from the diagnosis of myositis. (JAMA 1981;246:1921-1923).
|Original language||English (US)|
|Number of pages||3|
|Journal||Journal of the American Medical Association|
|State||Published - Oct 23 1981|
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