PRL and rheumatoid arthritis: Typically, prolactin elicits a ­proinflammatory response mediated by T helper lymphocytes type 1 (Th1) [10,11], and hyperprolactinemia is recognized as a pathological state (except during pregnancy) responsible for autoimmune diseases such as systemic lupus erythematosus, multiple sclerosis, rheumatoid arthritis, which are more prevalent in women, possibly because their prolactin levels are higher than in men [6,7,12–15].