SERPINA1 and systemic lupus erythematosus: Previously, studies of proteomic analysis had reported the abnormality of various serum/plasma protein levels in SLE patients, particularly the active stage, such as increased levels of haptoglobin [9], fibrinogen gamma chain [10], alpha-1-antitrypsin [11,12], apolipoprotein B [11,12], or the diminished level of apolipoprotein A-1 [9], histidinerich glycoprotein [10], clusterin [11], and albumin [12].