Elevated levels of serum prolactin in patients with advanced multiple myeloma.

BACKGROUND AND OBJECTIVE: The role of prolactin in immunoregulation and normal hemopoiesis is well known. However, prolactin also seems to be involved in the pathomechanism of malignancies and autoimmune diseases. Elevated serum prolactin levels were reported in patients with malignant lymphoma, colon and breast carcinoma, systemic lupus erythematosus and rheumatoid arthritis. Recently we demonstrated prolactin immunostaining in bone marrow cells of patients with multiple myeloma.

DESIGN AND METHODS: Serum prolactin levels of 56 patients with multiple myeloma, as well as serum beta(2)-microglobulin, and interleukin-6 concentrations were determined in this study.

RESULTS: Patients with advanced disease showed a significant increase in serum prolactin concentration, while patients with a clinical stage of I and II, and also control patients had normal values. The concentration of serum beta(2)-microglobulin and interleukin-6 changed in parallel with that of serum prolactin in patients with multiple myeloma. Determining serum prolactin levels several times during the disease process in a given patient clearly showed that the prolactin concentration was increasing during the disease progression.

INTERPRETATION AND CONCLUSIONS: Our results indicate a role of prolactin in disease progression in multiple myeloma.