Tuberous sclerosis complex (TSC) is a rare autosomal dominant disorder resulting from pathogenic variants in the TSC1 or TSC2 genes, leading to hyperactivation of the mechanistic target of rapamycin (mTOR) pathway and subsequent development of benign neoplasms in multiple organs. Kidney involvement is frequent, being angiomyolipoma the most common lesion. Angiomyolipoma can occur since childhood and progress throughout life, potentially leading to complications such as hemorrhage and chronic kidney disease (CKD). This study aims to characterize the kidney phenotype in a Brazilian cohort of TSC patients and identify potential risk factors associated with kidney complications. This real-world retrospective observational study analyzed data from TSC patients recorded on their first nephrology consultation at two Brazilian university hospitals between September 2019 and August 2024. Clinical, laboratory and imaging data were collected from medical records. Comparative analyses were conducted based on sex, history of kidney hemorrhage, kidney invasive interventions and CKD G3-G5D. 172 patients were included (28 ± 14.2 years, 62.2% female, 22.7% pediatric). Angiomyolipoma was the most frequent renal lesion (91.7%) with increasing prevalence with age, followed by cysts (45.2%). 41.9% of the patients meeting renal indications were receiving mTOR inhibitor. The prevalence of CKD G3-G5, kidney hemorrhage and interventions was 9.9%, 16.6%, and 27.9%, respectively. Comparative analysis matched by age showed that female patients have slightly lower eGFR (117 94–127 vs. 126 97–149 mL/min/1.73m 2 ; p = 0.02) and a trend toward higher prevalence angiomyolipomata ≥ 30 mm, kidney invasive interventions and larger angiomyolipomata size. Logistic regression identified age as the only factor independently associated with a history of kidney hemorrhage OR 1.06 (1.01–1.11). CKD G3-G5D was associated with older age, larger angiomyolipoma, previous kidney hemorrhage and invasive interventions. This Brazilian cohort study demonstrated that TSC-related kidney involvement may occur early in life, displays a progressive profile and leads to severe kidney outcomes. The high rates of kidney complications and the suboptimal utilization of mTOR inhibitors underscore the need to increase awareness, early referral to nephrologist and timely therapeutic intervention.
Monich et al. (Thu,) studied this question.