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

Purpose 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. Methods 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. Results 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 (B ND 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. Conclusions Women with HPRL had a higher prevalence of autoantibodies, higher serum levels of IL-4 and IL-6, and more B ND 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.