Method Forty-eight hospitals were included by mail or Email. The items of QC include ANA, anti-ENA antibody, anti-dsDNA antibody, anti-mitochondria antibody and anti-smooth muscle antibody. 方法通过发函的方式确定48家医院为参与单位,质控项目包括抗核抗体、抗dsDNA抗体、抗可提取性核抗原(ENA)抗体、抗线粒体抗体和抗平滑肌抗体(ASMA)。