Increased prevalence of kidney cysts in individuals carrying heterozygous COL4A3 or COL4A4 pathogenic variants.

BACKGROUND: Clinical variability among individuals with heterozygous pathogenic/likely pathogenic (P/LP) variants in the COL4A3/COL4A4 genes (also called autosomal dominant Alport syndrome or COL4A3/COL4A4-related disorder) is huge; many individuals are asymptomatic or show microhematuria, while others may develop proteinuria and chronic kidney disease (CKD). The prevalence of simple kidney cysts (KC) in the general population varies according to age, and patients with advanced CKD are prone to have them. A possible association between heterozygous COL4A3, COL4A4 and COL4A5 P/LP variants and KC has been described in small cohorts. The presence of KC in a multicenter cohort of individuals with heterozygous P/LP variants in the COL4A3/COL4A4 genes is assessed in this study. METHODS: We evaluated the presence of KC by ultrasound in 157 individuals with P/LP variants in COL4A3 (40.7%) or COL4A4 (53.5%) without kidney replacement therapy. The association between presence of KC and age, proteinuria, estimated glomerular filtration rate (eGFR) and causative gene was analyzed. Prevalence of KC was compared with historical case series in the general population. RESULTS: Half of the individuals with P/LP variants in COL4A3/COL4A4 showed KC, which is a significantly higher percentage than in the general population. Only 3.8% (6/157) had cystic nephromegaly. Age and eGFR showed an association with the presence of KC (P < .001). No association was found between KC and proteinuria, sex or causative gene. CONCLUSIONS: Individuals with COL4A3/COL4A4 P/LP variants are prone to develop KC more frequently than the general population, and their presence is related to age and to eGFR. Neither proteinuria, sex nor the causative gene influences the presence of KC in these individuals.

Is endovascular arteriovenous fistula a feasible alternative for hemodialysis patients?

INTRODUCTION: For hemodialysis (HD) patients, the selection of vascular access (VA) is a crucial factor that significantly affects morbidity and mortality. Historically, native Arteriovenous Fistulas (AVFs) have been established using surgical techniques. However, devices facilitating percutaneous endovascular arteriovenous fistula formation have recently been introduced in clinical practice, showing promising initial evidence. The primary objectives were technical success, efficacy, and cannulation rates. The secondary objectives included primary and cumulative patency, safety, and the number of procedures required to maintain fistula patency. METHODS: A prospective, single-center, single-arm study that included all patients who underwent endovascular arteriovenous fistulas (endoAVF) creation using the WavelinQ™ EndoAVF System at a University Hospital between December 2021 and August 2023. RESULTS: A total of 20 patients who underwent an endoAVF were included. Technical success was 100%. 75% (15) of the endoAVFs met the criteria for physiological suitability. The cannulation rate was 66% (10/15) for endoAVFs that reached physiological suitability. At 6 months of follow-up, the primary and cumulative patency rates were 65% and 75%, respectively; at 12 months, these were 50% and 70%, respectively. Serious adverse events were not observed. The reintervention rate was 0.33 procedures/patient-year. CONCLUSION: Based on our experience, creating AVFs using the WavelinQ 4-F EndoAVF system is safe and effective, with high technical success rates and acceptable patency and reintervention rates.