Fig 1. RANKL surface expression in leukocytes and monocyte phenotype.

A) RANKL⁺ frequency and absolute number in circulating leukocytes. CD66b⁺RANKL⁺ cells are increased in the circulation of patients at baseline and at follow-up when compared to healthy donors (frequency p = 0.0092; absolute number p = 0.005). At follow-up, CD3⁺RANKL⁺ are decreased in circulation when compared to healthy donors (frequency p = 0.0271; absolute number p = 0.0244). CD19⁺RANKL⁺ frequency is decreased after treatment when compared to patients at baseline (p = 0.0122) and with healthy donors (p = 0.0021). This difference is also observed at the absolute number level when compared to healthy donors (p = 0.0141). RANKL⁺ cells were analysed by flow cytometry and gated inside each subpopulation. B) Phenotype of circulating monocyte subpopulations—Classical CD14^brightCD16^-, intermediate CD14^brightCD16⁺, non-classical CD14^dimCD16⁺. CD62L is increased in the circulating classical subpopulation of patients at baseline (p = 0.0436) and at 6 months follow-up (p = 0.0158) when compared to healthy donors. CD62L expression is increased in patients after 6 months follow-up both in the non-classical subpopulation (compared to healthy p = 0.0398) and in the intermediate subpopulation (compared to healthy p = 0.001). CCR2 expression is reduced in the intermediate subpopulation of patients at follow-up when compared to healthy donors (p = 0.0307). Each dot represents a sample. Line represents median. * vs Baseline, § vs Follow-up. * and § p<0.05, ** and §§ p<0.01. MFI—Median fluorescence intensity.