Angiotensin-converting enzyme gene polymorphism in patients with psoriatic arthritis.

To investigate the frequency of angiotensin-converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism genotypes in adults with psoriatic arthritis (PsA), a heterogeneous chronic disease with autoimmune pathology. ACE gene I/D polymorphism influences the plasma and tissue levels of ACE and has an involvement in inflammatory mechanism. The frequency of ACE gene I/D polymorphism genotypes was determined in 51 adults with PsA from Kuwait, and compared to that in 100 ethnically matched healthy controls using polymerase chain reaction. The distribution of ACE I/D polymorphism and allele frequencies in PsA patients were not significantly different from controls (P > 0.05). Further analyses of PsA patients showed that ACE I/D gene polymorphism was not associated with family history, clinical manifestations, and disease severity. However, the frequency of II genotype was significantly higher in patients with late disease onset than in those with early onset (25 vs. 3%; P = 0.04). No difference was found between the distribution of the ACE genotype in PsA patients and the general population in Kuwait. However, the presence of II genotype may confer susceptibility to the development of late onset PsA.

Angiotensin converting enzyme gene insertion-deletion polymorphism is associated with juvenile rheumatoid arthritis.

OBJECTIVE: To investigate the incidence of angiotensin converting enzyme (ACE) gene insertion-deletion (I/D) polymorphism genotypes in children with juvenile rheumatoid arthritis (JRA), a heterogeneous chronic disease with autoimmune pathology. ACE gene I/D polymorphism influences the plasma and tissue levels of ACE and has an involvement in inflammatory mechanisms. METHODS: The incidence of ACE gene I/D polymorphism genotypes was determined in 82 children with JRA from Kuwait and compared to that in 48 ethnically matched healthy controls using polymerase chain reaction. RESULTS: A considerably higher incidence of II genotype was observed in the JRA patients compared to controls (p < 0.003). In contrast, no statistically significant difference was detected in the incidence of DD and ID genotypes in JRA patients and controls (p = 0.276 and 0.460, respectively). The incidence of ACE gene polymorphism genotypes was also studied in clinical subclasses of JRA patients and controls. There was no significant difference in the incidence of DD and ID genotypes in either of the 3 JRA subclasses (oligoarticular, polyarticular, and systemic) when compared to controls. However, the incidence of II genotype was found to be significantly higher in all the 3 JRA subclasses compared to controls. The strongest association between II genotype and JRA subclasses was detected in systemic JRA, followed by oligoarticular and polyarticular JRA. This was also reflected in a higher prevalence of I-allele in the systemic JRA cases (13/26, 50%) compared to the D-allele (11/26, 42%). In contrast, D-allele of the ACE gene was more prevalent in oligoarticular and polyarticular JRA cases, than the I-allele (61% and 58%, respectively). CONCLUSION: Our data suggest a significant association of the I-allele of the ACE gene I/D polymorphism with the 3 clinical subclasses of JRA in children, and the highest association was observed in systemic JRA cases.