Fig. 4

Association of IgG anti-MDA with serological and clinical measurements of disease. The correlation with clinical measurements and biomarkers of immunoglobulin (Ig)G anti-phosphorylcholine (PC) (a) and IgG anti-malondialdehyde (MDA) (b) normalized for total IgG. Spearman correlation R values are shown on the x axis. Significant Spearman correlations with p < 0.05 are highlighted in black and nonsignificant correlations are shown in gray. Notably, IgG anti-MDA significantly directly correlated with inflammation biomarkers and disease activity, while IgG anti-PC generally demonstrated an inverse correlation with inflammation measurements. IgG anti-MDA also significantly correlated with low complement (C) levels. See Additional file 1:Table S3 for more details of the analysis. The figure was generated using the R statistical package (www.r-project.org). ESR erythrocyte sedimentation rate, GFR glomerular filtration rate, hsCRP high-sensitivity C-reactive protein, SLAM Systemic Lupus Activity Measure, SLEDAI Systemic Lupus Erythematosus Disease Activity Index, SLICC Systemic Lupus International Collaborating Clinics, sTNFR soluble tumor necrosis factor receptor, VCAM-1 vascular cell adhesion molecule 1