Prevalence of Kidney Complications in a Large Cohort of Patients with Recessive Dystrophic Epidermolysis Bullosa

Abstract Background Renal manifestations in patients with recessive dystrophic epidermolysis bullosa (RDEB) due to collagen VII deficiency have only been described in case series and could thus be underestimated. Objectives We aimed to describe the prevalence and types of kidney disease in a large cohort of patients with RDEB. Methods We conducted a retrospective study in two Parisian reference centers for RDEB and included patients with at least two concurrent blood and urine analyses. Kidney disease was defined as either glomerular with elevated albuminuria or tubulointerstitial with elevated β2-microglobulinuria. Results We included 120 patients with a confirmed molecular diagnosis of RDEB characterized by collagen VII deficiency between 2005 and 2021, of whom 36 (30%) exhibited kidney disease. Of these, 15 (12.5%) displayed glomerular disease, most commonly due to IgA nephropathy, and 21 (17.5%) presented with a tubulointerstitial presentation, often associated with complex hydroelectrolytic disorders. The immunohistochemistry study with anti-collagen VII antibody was positive on glomerular and tubular basement membranes in controls and negative in patients with complete collagen VII deficiency. In multivariate analysis, kidney disease was significantly associated with disease severity (p=0.002). Overall survival was reduced in RDEB patients with kidney complications. Based on these findings, we propose recommendations for the detection and monitoring of kidney disease in this patient population, with early referral to a nephrologist specifically upon the identification of renal abnormalities. Conclusions Kidney disease is common, correlates with disease severity, and impacts the prognosis of patients with RDEB. Systematic screening is recommended in this population.