Fig. 2
Correlation of oxidation-associated IgG autoantibody reactivity to PC and MDA with lupus-associated autoantibody reactivities. The result from Spearman analysis of the correlation between serum immunoglobulin G (IgG) anti-phosphorylcholine (PC) (a) or IgG anti-malondialdehyde (MDA)-modified protein (b) levels with SLE-associated IgG autoantibody levels and total IgG in 398 SLE patients from the Karolinska cohort. Spearman p values are shown on the y axis and Spearman R values are shown on the x axis for each independent correlation analysis. Significant Spearman correlations with p < 0.05 are highlighted in black and nonsignificant correlations are shown in gray. IgG anti-MDA levels correlated especially strongly with IgG anti-nucleosome and IgG anti-dsDNA levels while IgG anti-PC demonstrated a distinct pattern and the strongest correlation with antiphospholipid antibodies (IgG anti-cardiolipin (CL)/β2-glycoprotein-I (β2GPI)). IgG anti-PC and IgG anti-MDA levels were determined in serum by ELISA. See Additional file 1:Table S1 for more details of the analysis. The figure was generated using the R statistical package (www.r-project.org)