Serum amylase and macroamylase in patients with systemic lupus erythematosus.

We measured serum amylase and macroamylase activity in 25 patients with systemic lupus erythematosus (SLE) and 15 controls. The mean (+/- SD) for SLE was greater than for the controls (161 +/- 71.8 versus 116 +/- 38.8 units/dl). Five patients (20%) had elevated amylase and 6 (25%) had a macroamylase present. None of the controls had amylase elevation or macroamylase. None of the patients had abdominal pain and there was no observable correlation of amylase activity with disease activity, drugs, or renal function. Elevation of serum amylase in SLE without pancreatitis is frequent, as is the presence of macroamylase. Autoantibodies to this serum enzyme may be frequent in SLE.