Presence of IgG anti-β2GPI and anti-thrombin antibodies in 124 LN patients. (a) Plasma samples from 25 patients with lupus nephritis and glomerular microthrombosis (LN-GMT), 99 patients without GMT (LN-non-GMT), and 100 normal controls were analyzed for IgG anti-β2 glycoprotein I (β2GPI) antibodies at a dilution of 1:201. Horizontal bars indicate the median values; the dashed line represents the cutoff value (20 RU/ml). (b) Plasma samples from LN-GMT group, LN-non-GMT group, and 100 normal controls were analyzed for IgG anti-thrombin antibodies at a dilution of 1:100. Horizontal bars indicate the median OD for each group; the dashed line represents the cutoff, which is mean OD+ three standard deviations of the 100 normal controls. Results are representative of two experiments.