Circulating 20S proteasome levels in patients with mixed connective tissue disease and systemic lupus erythematosus

The associations of circulating 20S proteasomes (c20S) with clinical and serologic disease indices in patients with systemic lupus erythematosus (SLE) and mixed connective tissue disease ( MCTD) are unknown. We present the initial report that c20S levels are elevated in MCTD and correlate with clinically relevant changes in disease activity in SLE and MCTD.