CD21low B cells in systemic sclerosis: A possible marker of vascular complications

Abstract

Objectives: 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).

Materials and methods: 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.

Results: 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.

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

Keywords: B cells; CD21(low); Kidney; Pulmonary arterial hypertension; Systemic sclerosis.