Hyperprolactinemia is associated with a high prevalence of serum autoantibodies, high levels of inflammatory cytokines and an abnormal distribution of peripheral B-cell subsets.

Abstract

Hyperprolactinemia (HPRL) has been reported in many autoimmune diseases. However, the serum autoantibody profile and peripheral B-cell subset distribution in women with HPRL are largely unknown. The current study aimed to investigate the autoantibody prevalence and cytokine levels as well as to further explore the B-cell subset distribution in women with HPRL. Sera from 202 women with HPRL and 97 healthy women were included in this study. All sera were examined for prolactin (PRL), anti-nuclear antibody (ANA), rheumatoid factor, anticardiolipin (ACL), immunoglobulin G, immunoglobulin M, complement 3, complement 4, interleukin 4 (IL-4) and interleukin 6 (IL-6). Peripheral blood was collected from 22 women with HPRL and 19 healthy women, and B-cell subsets were measured by flow cytometry. At least one autoantibody was found in 47 out of 202 women with HPRL compared with 9 of 97 healthy women (p < 0.001). The levels of IL-4 (p < 0.0001) and IL-6 (p < 0.0001) were significantly higher in women with HPRL than in healthy women. The percentages of naive IgD+IgM- B cells (BND cells, p < 0.0001), antibody-secreting cells (p = 0.007) and unswitched memory B cells (p = 0.004) among the total B cells from HPRL women were significantly higher than those from healthy women. Women with HPRL had a higher prevalence of autoantibodies, higher serum levels of IL-4 and IL-6, and more BND cells, antibody-secreting B cells and unswitched memory B cells than healthy women. These data imply that a high level of PRL is associated with autoimmune diseases.