Increased plasma/serum levels of prolactin in multiple sclerosis: a meta-analysis

ABSTRACT

Objectives: Prolactin (PRL) is a polypeptide hormone that is known to stimulate humoral and cell mediated immune responses. PRL levels have been investigated in several autoimmune diseases including multiple sclerosis (MS); however, these have yielded different and inconsistent results. This study aims to perform a more precise evaluation on the plasma/serum PRL levels in MS patients, and to explore the available influential factors.

Methods: Research related to plasma/serum PRL levels in MS patients and healthy controls were gathered using PubMed, EMBASE and The Cochrane Library database (until Mar 31 2016). Pooled standard mean difference (SMD) with 95% confidence interval (CI) was calculated by fixed-effects or random-effect model analysis. Heterogeneity test was performed by the Q statistic and quantified using I², and publication bias was evaluated using a funnel plot and Egger’s linear regression test.

Results: 516 articles were obtained after searching databases, and 8 studies with 426 MS patients and 296 controls were finally included. Meta-analysis revealed that, compared with the control group, the MS group had significantly higher plasma/serum PRL levels, with the SMD of 0.55 and 95%CI (0.39, 0.72). Subgroup analyses showed that region, age and disease duration were associated with PRL level in MS patients.

Conclusion: In summary, our meta-analysis revealed a significantly higher PRL level in MS patients than healthy controls, and it is influenced by region, age and disease duration.

KEYWORDS:

• Multiple sclerosis
• MS
• prolactin
• hormone
• meta-analysis

Declaration of interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Additional information

Funding

This paper was not funded.