CD21^low B cells in systemic sclerosis: A possible marker of vascular complications

To evaluate expansion of CD21^low B cells and their role in B cell homeostasis, apoptosis, clinical manifestations and serum vascular endothelial growth factor (VEGF) in systemic sclerosis (SSc).

B-cells subpopulations and apoptosis have been assessed in 74 SSc patients and 20 healthy donors. Renal Doppler ultrasound, echocardiography, pulmonary function test and VEGF were performed.

SSc patients with expanded CD21^low B cells (SSc-CD21^low) show a distinct B cell profile with increased memory B cells compared to patients without CD21^low B cells (SSc-CD21⁺). Renal resistive index, systolic pulmonary arterial pressure and FVC/DLCO ratio were significantly higher in SSc-CD21^low group than SSc-CD21⁺, DLCO was lower in SSc-CD21^low group than SSc-CD21⁺. We found a positive linear correlation between CD21^low and sPAP, RI and FVC/DLCO ratio whereas a negative correlation was observed between CD21^low and DLCO and VEGF levels.

CD21^low B cells are increased in SSc patients with visceral vascular manifestations.