Impact of aldosterone synthase gene C-344T polymorphism on IgA nephropathy.

AIM

In the past years, aldosterone has been identified as an important mediator of renal injury. In this study, we evaluated the influence of C-344T polymorphism of aldosterone synthase gene, associated with serum aldosterone levels and the development of arterial hypertension, on IgA nephropathy (IgAN).

METHODS

We studied n = 143 patients with biopsy-proven IgAN followed up for 7.1 ± 6.2 years. Patients were classified according to the slope of reciprocal serum creatinine into group A (slow progressors, n = 93) and group B (fast progressors, n = 50). One hundred healthy volunteers were analyzed as controls. The biopsies of n = 79 patients were reviewed and analyzed by the same pathologist. Aldosterone synthase gene C-344T polymorphism was determined by polymerase chain reaction amplification.

RESULTS

The genotype distribution was similar in patients and control subjects [not significant (ns)]. Age, initial renal function, proteinuria, and blood pressure did not differ significantly between patients with different genotypes (ns). The percentage of sclerosed glomeruli tended to be higher among patients carrying the CC/CT genotypes (29.4 ± 26.5% vs. 21.7 ± 25.2% in TT genotype; ns). C-344T polymorphism was associated with the progression of IgAN as shown by the different genotype frequencies in group Α (slow progressors,

CC/CT: 60.2%, TT: 39.8%) and group B (fast progressors,

CC/CT: 78.0%, TT: 22:0%; p = 0.032).

CONCLUSION

Our results indicate that aldosterone synthase gene C-344T polymorphism is a risk factor for accelerated progression in Caucasian patients with IgAN.