Increased microvascular disease in X-linked and autosomal recessive Alport syndrome: a case control cross sectional observational study

Abstract

ABSTRACTBackground: Retinal microvascular disease reflects, in part, poor blood pressure control and systemic microvascular disease contributes to renal failure progression. This study examined the retinal microvasculature in Alport syndrome.Materials and Methods: Retinal images from 28 males and 28 females with X-linked Alport syndrome, and 13 individuals with autosomal recessive disease were reviewed retrospectively for microvascular/ hypertensive retinopathy (Wong and Mitchell classification), and small vessel calibre (using a computerised semiautomated method and revised Knudtson formula). Data were compared with age and gender-matched individuals with normal blood pressure and renal function.Results: Microvascular/hypertensive retinopathy was more common in males and females with X-linked Alport syndrome than age- and gender-matched controls (23, 82% and 10, 36%, p < 0.01; and 21, 75% and 13, 48%, p = 0.05, respectively), and in individuals with autosomal recessive disease compared with controls (12, 92% and 16, 43%, p < 0.01). Moderate microvascular/hypertensive changes were present in males and females with X-linked or autosomal recessive disease but not controls.Arteriolar calibre was reduced in males with X-linked disease (142.5 ± 18.7 µm, and 150.7 ± 10.1 µm, p = 0.046) and in autosomal recessive disease (133.5 ± 11.10 µm and 149.1 ± 10.6 µm, p < 0.0001).Microvascular/hypertensive retinopathy and arteriolar narrowing in males with X-linked disease were not different after renal transplantation and before (p NS).Conclusions: Microvascular/hypertensive retinopathy was more common and more severe in Alport syndrome than normotensive controls. Improved BP levels may further slow the rate of renal functional decline in Alport syndrome.