Kidney involvement in tuberous sclerosis complex: the impact on healthcare resource use and costs

Abstract

Objective: Tuberous sclerosis complex (TSC) is associated with non-malignant kidney lesions-angiomyolipomatathat may be associated with chronic kidney disease (CKD). This study investigated the relationship between renal angiomyolipomata and CKD in TSC, including the impact on healthcare resource utilization (HCRU) and costs. Methods:This was a retrospective, longitudinal cohort study based on medical record data spanning January 1990-April 2012 for 369 TSC patients treated at a specialty center in the Netherlands. Cohorts were established based on CKD stage and angiomyolipoma size. Rates of HCRU (physician visits, monitoring, and interventions) were compared across cohorts using rate ratios. Healthcare costs were compared across cohorts using cost differences. Regression models were used to identify predictive factors for HCRU and healthcare costs. Results:Sixteen per cent of patients reached CKD stage 3 or higher during follow-up. Patients at more advanced stages of CKD more frequently had either large or multiple small angiomyolipomata and higher HCRU rates and healthcare costs. In the multivariate analyses, male gender, CKD stage 41, angiomyolipoma size !3.5 cm, embolization, and the presence of moderate or severe lymphangioleiomyomatosis (LAM) were associated with greater HCRU (p 0.002 for all comparisons). Definite (vs suspected) TSC diagnosis, CKD stage 5 (vs CKD stage 1), angiomyolipoma size !3.5 cm, and moderate or severe LAM were associated with higher costs (p ¼ 0.050 for TSC diagnosis, p 0.002 for other comparisons). Costs in CKD stage 5 were driven primarily by dialysis. Conclusions:A substantial proportion of patients with TSC developed moderate-to-severe CKD, which was associated with renal angiomyolipomata and increased HCRU and costs.

The economic burden of tuberous sclerosis complex in UK patients with renal manifestations: a retrospective cohort study in the clinical practice research datalink (CPRD)

“…By adulthood, 60-80% of TSC patients will have developed renal manifestations [18][19][20] , and most deaths over the age of 30 in TSC patients can be attributed to renal disease 21 . Renal involvement manifests as renal angiomyolipomas, cysts, malignant tumors, polycystic kidney disease, and renal insufficiency [22][23][24] . Renal angiomyolipomas and cysts begin developing in 55-80% of children 23,25 and become more severe in adults 26,27 , where roughly 80% of patients may present with this manifestation 28 .…”

“…Renal angiomyolipomas and cysts begin developing in 55-80% of children 23,25 and become more severe in adults 26,27 , where roughly 80% of patients may present with this manifestation 28 . Renal angiomyolipomas are also the most common renal manifestation 24 and often present bilaterally and in multiples 15,24,29 . Renal angiomyolipomas increase in size over time; once they grow large (>3-4 cm), patients become at risk of life-threatening hemorrhage 24 due to inelastic blood vessels, characteristic of renal angiomyolipomas, which are susceptible to rupture 21,30 .…”

“…Renal angiomyolipomas are also the most common renal manifestation 24 and often present bilaterally and in multiples 15,24,29 . Renal angiomyolipomas increase in size over time; once they grow large (>3-4 cm), patients become at risk of life-threatening hemorrhage 24 due to inelastic blood vessels, characteristic of renal angiomyolipomas, which are susceptible to rupture 21,30 . These lesions are associated with decreased kidney function and moderateto-severe chronic kidney disease (CKD) 24 ; this increases healthcare resource use (HCRU) and carries an associated 5-times greater mortality risk 30 .…”

“…Renal angiomyolipomas increase in size over time; once they grow large (>3-4 cm), patients become at risk of life-threatening hemorrhage 24 due to inelastic blood vessels, characteristic of renal angiomyolipomas, which are susceptible to rupture 21,30 . These lesions are associated with decreased kidney function and moderateto-severe chronic kidney disease (CKD) 24 ; this increases healthcare resource use (HCRU) and carries an associated 5-times greater mortality risk 30 . Advanced CKD can lead to serious cardiovascular complications resulting from the hypertension and dyslipidemias promoted by renal insufficiency 31 .…”

“…Advanced CKD can lead to serious cardiovascular complications resulting from the hypertension and dyslipidemias promoted by renal insufficiency 31 . CKD has been shown to progress more quickly in TSC patients than the general population and is related to morbidity and mortality 24 . Renal cysts manifest in 14-32% 18,19,32 of TSC patients and most often present as a single cyst or small, multiple, asymptomatic lesions 25 .…”