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 CD27high plasma cells. Abnormalities in the distribution ofCD27+ B cell subsets are useful in assessing disease activity in patients with systemic lupus erythematosus (SLE). In particular, the frequency of CD27high plasma cells significantly correlates with lupus activity in both children and adults with SLE. Conventional immunosuppressive therapies affect the number of CD27- naïve B cells and CD27high 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.