Sex and systemic lupus erythematosus: the role of the sex hormones estrogen and prolactin on the regulation of autoreactive B cells.

PURPOSE OF REVIEW

For many decades, it has been speculated that sex hormones play a role in systemic lupus erythematosus. Recent data accumulated during the past few years provide striking evidence that hormonal modulation of B cells can have a profound impact on the survival, maturation and repertoire selection of autoreactive B cells and begin to explain the sex bias associated with the condition.

RECENT FINDINGS

While there are still insufficient clinical data to define a role for estrogen or prolactin in human systemic lupus erythematosus, recent studies of anti-DNA antibody transgenic mice clearly demonstrate that an elevation in either estrogen or prolactin breaks tolerance of high affinity DNA-reactive B cells and induces a lupus phenotype. B cells with the same antigenic specificities are rescued by either estrogen or prolactin, but estrogen promotes the survival and activation of the T independent marginal zone B cell subset, while prolactin promotes the survival and activation of the T dependent follicular B cell subset.

SUMMARY

Elevations in the levels of estrogen or prolactin can promote the survival and activation of high affinity autoreactive B cells. These hormones engage different B cell pathways to interfere with B cell tolerance. The identification of systemic lupus erythematosus patients with either an estrogen-responsive or prolactin-responsive disease will further the development of therapeutics that can specifically modulate hormonal responses.