Circulating Prolactin Level in Juvenile Systemic Lupus Erythematosus and Its Correlation with Disease Activity: a Case Control Study

Background: The linkage between prolactin (PRL) and systemic lupus erythematosus (SLE) is still vague. Determination of serum levels of prolactin to reveal its role in patients with SLE is the aim of the study.

Methods: This is a case-control study performed on 40 children with SLE and 40 age- and sex-matched controls. Cases were further subdivided according to disease activity into mild, moderate, and severe groups using the SLEDAI (Systemic Lupus Erythematosus Disease Activity Index) score. Serum prolactin levels were assayed by ELISA (enzyme-linked immunosorbent assay).

Results: prolactin level was significantly higher in SLE patients (17.3 ± 6.6 µg/L) than in controls (13.5 ± 5.3 µg/L) (P value = 0.005). Although the prolactin level was highest in severe cases (19.3 ± 7.7 µg/L), followed by moderate cases (17.0 ± 5.3 µg/L), and lowest in mild cases (14.0 ± 6.2 µg/L), the variance between the 3 groups was not statistically significant (P value = 0.212). A significant positive correlation between prolactin level and SLEDAI score was detected (r = 0.368) (P value = 0.019). Hyperprolactinemia was found in 8 patients (20%) but not in controls; 4 out of 8 patients with hyperprolactinemia (50%) showed neurological manifestations compared to only 3 out of 32 patients with a normal prolactin level (9.4%) (P value = 0.007).

Conclusion: A relationship between serum prolactin levels and juvenile SLE disease was detected. Neurological manifestations were more prevalent among SLE patients with hyperprolactinemia.