Plasma cells in systemic lupus erythematosus: the long and short of it all.

Plasma cells can be classified as long- or short-lived. The lifespan of a plasma cell largely depends on whether it arises from a germinal center or an extrafollicular locus and most importantly whether it can find a survival niche in the spleen or BM. In systemic lupus erythematosus (SLE) patients, long-lived plasma cells are believed to be responsible for the production of anti-RNA and anti-cardiolipin antibodies, whereas short-lived plasma cells, which are more susceptible to anti-proliferation therapies, are the main producers of anti-DNA antibodies. A previous study showed that transient overexpression of interferon-α (IFN-α), a cytokine that plays a pathogenic role in SLE, accelerates disease onset in lupus-prone NZB/W mice. In this issue of the European Journal of Immunology, the same group report that IFN-α induces large numbers of short-lived plasma cells, accompanied by high titers of anti-dsDNA antibodies in NZB/W, but not BALB/c, mice. Our commentary discusses this interesting observation in the context of the previous data regarding plasma cell differentiation and conveys our view about the clinical implications with respect to therapies that target plasma cells in SLE patients.