Relation of serum prolactin level to systemic lupus erythematosus disease activity: the effect of immunosuppressive medications

ABSTRACT

The relationship between serum prolactin level and disease activity state and the effect of conventional immunosuppressive medications is still unclear with contradictory results. To study the correlation of prolactin levels with SLE disease activity at the beginning of the study and after 9 months of conventional treatment, this may clear the role of prolactin in the pathogenesis of SLE. Forty five active SLE patients were enrolled in this study, all were females and they were fulfilling the ACR criteria for SLE classification. Patients under medical treatment with drugs that may affect prolactin level as [bromocriptine, chlroquine, cimetidine, metoclopramide ..etc] were excluded. No patient known to have either heart failure, liver failure or kidney failure was allowed in this study. The patient was divided into 2 groups Group I Twenty three patients with minor organ affection [cutaneous and joint affection], Group II Twenty two patients with major organ affection [glomerulonephritis], Group III Thirty control apparently healthy persons. Serum prolactin was determined with double antibody liquid phase radioimmunoassay at entry and after 9 months of conventional treatment and SLE patients serum prolactin levels were correlated with SLE disease activity index score [SLEDAI]. Our results showed that 31 patients had mild hyperprolactinemia [68.8%], 13 patients in group I and 18 patients at group II. Comparing the serum prolactin levels between SLE patients in both groups I and group II versus control showed a significant increase. After treatment of SLE patients for 9 months, the serum prolactin level showed a significant decrease from a mean [25.6 +/- 5.2 ng/ml] at the beginning to a mean [14.9 +/- 10.2 ng/ml] [p<0.001]. Comparison of SLEDAI scores at the beginning of the study and after 9 months of treatment showed a significant decrease from a mean [15.9 +/- 4.8 ng/ml] to [2.3 +/- 1.7 ng/ml] p<0.001. There was a significant correlation between serum prolactin levels and SLEDAI score at beginning [r = 0.4785], p = 0.0006 and after treatment r = 0.8975, p< 0.001. There is a significant correlation between SLE disease activity and serum prolactin which could be decreased equally by the conventional immunosuppressive treatment. This support that there is a role of prolactin in the pathogenesis of SLE