Correlation of circulating CD27high plasma cells and disease activity in systemic lupus erythematosus

CD27 is a useful marker in assessing the number of circulating B cells and B cell subsets because it permits one step identification of the major B cell compartments, CD27^- naïve and CD27⁺ memory B cells as well as CD27^high plasma cells. Abnormalities in the distributionof CD27⁺ B cell subsets are useful in assessing disease activity in patients with systemic lupus erythematosus(SLE). In particular, the frequencyof CD27^high plasma cells significantly correlates with lupus activity in both children and adults with SLE. Conventional immunosuppressive therapies affect the number of CD27^- naive B cells and CD27^high plasma cells, but do not target CD27⁺ memory B cells. These results suggest that disease flares may relate to the retention of CD27⁺ memory B cells after conventional immunosuppressive therapy and that new therapies that target these cells specifically may offer new opportunities to induce remission in SLE.