Fig 2: Serum anti-CCL21 antibody level in healthy controls and patients with different systemic connective tissue diseases. The dots in healthy controls (green), Systemic sclerosis (SSc; pink), primary Sjøgren syndrome (SS; purple), Systemic lupus erythematosus (SLE; blue) and Mixed connective tissue disease (MCTD; orange) shows the level of anti-CCL21 in the different patients. The dotted line represents the cut off value for considering the patients positive or negative for anti-CCL21, in which the patients above the dotted line are positive for anti-CCL21 antibodies. Levels of anti-CCL21 antibodies were significantly higher in patients with SSc, SS and SLE than in healthy controls (p-value).

Fig 3: CCL21 levels in SSc, SS and MCTD of anti-CCL21 antibody positive and negative patients. (A) Mean serum levels of CCL21 in anti-CCL21 antibody positive (green) and anti-CCL21 antibody negative (red) patients in SSc, SS and MCTD. (B) Mean serum levels of CCL21 of anti-CCL21 antibody positive (green) and anti-CCL21 antibody negative (red) patients in SSc patients diagnosed with PAH.

Fig 4: ROC analysis of CCl21 levels from ELISA 1, Luminex and ELISA 2. (A) ROC analysis of CCL21 levels from ELISA 1 with AUC=0.843, 95% CI = 0.084-0.883 and p<0.001, (B) ROC analysis of CCL21 levels from Luminex with AUC=0.772, 95% CI = 0.711-0.833 and p<0.001, and (C) ROC analysis of CCL21 levels from ELISA 2 with AUC=0.770, 95% CI = 0.711-0.830 and p<0.001.

Fig 5: Western blot of SSc serum samples. The four first lanes show the IP product of 1: costume made CCL21, 2: Tailless CCL21, 3: Patient serum 1, and 4: patient serum 2. The last two lanes CCL21 and Tailless CCL21 directly loaded on the gel.