Angiotensin-converting enzyme insertion/deletion gene polymorphism in multiple sclerosis: a meta-analysis

The activity of angiotensin-converting enzyme (ACE) has been increased in the blood and cerebrospinal fluid of multiple sclerosis (MS) patients. In addition, there has been suppression of disease development in experimental autoimmune encephalomyelitis after blockade of ACE. These findings suggest that ACE may play a role in the MS pathogenesis. Since the previous studies investigating the association between the insertion/deletion (I/D) polymorphism in intron 16 of the ACE gene and MS reported contradictory results, we performed a meta-analysis of four studies conducted in European populations of Slavic origin (1062 patients and 1067 controls) using the Comprehensive Meta-analysis 3.0 software. The results demonstrated that the ACE I/D polymorphism had no statistically significant association with an increased MS risk (all p ≥ 0.05) under all genetic comparison models: (1) allelic (D vs. I), (2) recessive (DD vs. ID + II), (3) dominant (DD + ID vs. II), and (4) additive (DD vs. ID vs. II). This meta-analysis indicates that the ACE I/D polymorphism is not associated with susceptibility to MS in Europeans of Slavic origin. Further studies with larger sample sizes from genetically different populations are warranted.