#4881 nephroprotection in boys with x-linked alport syndrome: the sooner the better

Abstract Background and Aims Proteinuria (Pr) is a marker of glomerular diseases progression. The aim of study was to define the efficiency of angiotensin-converting enzyme inhibitors (ACEi) treatment in prevention of Pr development in boys with X-linked Alport's syndrome (XLAS). Method Single center observation study included boys with confirmed XLAS (n = 87). Twenty nine pts (1gr) started ACEi (enalapril 4.2±1.4 mg/m2/day) in non-proteinuric stage of disease (Pr≤100 mg/m2/day); mean age 6.2±3.9 yrs, eGFR Schwartz 118±15.2 ml/min/1.73 m2, Pr 67±23 mg/m2/day. Fifty eight pts (2gr) without preemptive ACEi treatment were observed from mean age 6.8±4.9 yrs, eGFR 119±17.3 ml/min/1.73 m2, Pr 87±43 mg/m2/day. Follow up was 6.2±3.9 yrs, mean age at the last observation was 11.7±3.9 yrs vs 14.2±4.6 yrs (p = 0.67) in 1gr and 2gr, respectively. The occurrence of Pr (Pr>100 mg/m2/day) was defined as primary end point of the study. Results The pts of 1gr had lower rate (0.48 vs 0.94, p<0.001) and higher age (10.2±3.9 vs 4.9±3.4 yrs, p = 0.3) of Pr occurrence than in 2gr. ACEi treatment reduced risk of Pr onset (OR = 0.05(95%CI 0.013-0.2)) with absolute risk reduction of Pr by 47% (RD = 0.47) and number of treated pts to prevent Pr development (NNT) 2.14. No difference was revealed between 1gr pts with and without Pr development in age of therapy start (7.1±3.3 vs 6.3±2.8 yrs), ACEi dose (2.3±0.8 vs 2.1±0.6 mg/m2/day) and COL4A5 gene mutation type (missense variants 0.72 vs 0.86). Arterial hypertension was a risk factor of Pr occurrence in 1gr (χ2 = 4,42, p = 0.04); children with Pr development was older at the last observation: 13.5±3.2 vs 9.9±3.8 yrs, p = 0.47. No side effects of treatment were observed. Conclusion The early ACEi therapy halves the risk of Pr development in boys with XLAS and may prevent the disease progression in these patients.