Hyperprolactinemia in patients with systemic lupus erythematosus: correlation with disease activity

Aim:  Recent accumulated evidence suggests that prolactin is an important immunomodulator and may have a role in the pathogenesis of systemic lupus erythematosus (SLE). Our aim was to assess the frequency of hyperprolactinemia in women with SLE and to evaluate its correlation with disease activity. Method:  Plasma prolactin levels were measured in 35 women with SLE and 60 age- and sex-matched healthy controls. Disease activity was assessed using the SLE disease activity index (SLEDAI). Patients with a score > 10 were considered active. In patients and controls prolactin levels were determined by immunoradiometric assay (IRMA). Results:  The prolactin level was higher in SLE than in the control group: 28.5% of SLE patients versus 3.3% of controls had high prolactin levels. Patients with active disease had a trend to higher mean prolactin levels than inactive patients. SLE was active in 90% of hyperprolactinemic patients. In normoprolactinemic patients active disease was found only in 36% of patients. A statistically significant correlation was found between prolactin levels and SLE disease activity index. Conclusion:  This study shows that moderate hyperprolactinemia is present in a subset of patients with SLE and that it is related to increased disease activity and major organ involvement.