Background Prolactin has an immune stimulatory effect and may promote autoimmunity by encouraging the development of antigen presenting cells expressing MHC class II and co-stimulatory molecules and modulating IFN-γ secretion.
Objectives This study aimed to evaluate the relationship between circulating prolactin level and systemic lupus erythematosus (SLE), and to establish a correlation between plasma/serum prolactin levels and SLE activity.
Methods We performed a literature search for studies that examined prolactin status in SLE patients and controls, and the relationship between circulating (serum or plasma) prolactin levels and SLE using PUBMED, EMBASE, and Cochrane databases. We conducted a meta-analysis comparing the plasma/serum prolactin levels in patients with SLE to controls, and examined correlation coefficients between circulating prolactin level and SLE disease activity.
Results Twenty-five studies with a total of 1,056 SLE patients and 426 controls were included. Prolactin levels were significantly higher overall in the SLE group than in the control group (SMD =0.987, 95% CI =0.512 – 1.463, p=4.7x10-5). Stratification by ethnicity showed significantly elevated prolactin levels in the SLE group in Asian, Latin American, and mixed populations (SMD =0.813, 95% CI =0.137 – 1.490, p =0.018; SMD =0.981, 95% CI =0.307 – 1.655, p =0.004; SMD =1.469, 95% CI =0.443 – 2.495, p =0.005, respectively), but not in the European population. Meta-analysis of correlation coefficients showed a significantly positive correlation between circulating prolactin level and SLE activity (Correlation coefficient =0.379, 95% CI =0.026–0.487, p=4.0x10-9).
Conclusions Our meta-analysis demonstrated that circulating prolactin levels are higher in patients with SLE and that a significantly positive correlation exists between prolactin levels and SLE activity.
Disclosure of Interest None declared