Causes of death in patients with tuberous sclerosis

Kidney transplantation in patients with tuberous sclerosis complex

BACKGROUND

Tuberous sclerosis complex (TSC) is a disorder of the mammalian target of the rapamycin (mTOR) pathway associated with the development of multisystem tumors, including renal angiomyolipoma (AML). These renal tumors are benign by nature but locally invasive and carry a risk for the progression of chronic kidney disease (CKD) to end stage kidney disease (ESKD). The frequency of subsequent renal transplantation in this population is largely uncharacterized, although single-center data suggests that 5%-15% of adult TSC patients are kidney transplant recipients.

METHODS

This retrospective cohort study utilized United Network for Organ Sharing (UNOS) data. We included candidates waitlisted between 1987 and 2020 for a first kidney transplant with TSC-associated kidney failure. We utilized descriptive statistics to characterize the frequency of first-time kidney transplant waitlisting and transplantation among persons with TSC and the Fine-Gray subdistribution hazard model to evaluate characteristics associated with progression from waitlist.

RESULTS

We identified 200 TSC-associated kidney failure patients within the waitlist cohort. Of these, 12 were pediatric patients. Two-thirds (N = 134) of waitlisted persons were female. One hundred forty patients received a transplant with a median waitlist time of 2 years. Younger age at waitlisting was associated with a greater probability of progressing to transplant (HR 0.98 [95% CI: 0.96-0.99]). 91.8% of kidney transplant recipients survived 1-year post-transplant with a functioning allograft.

CONCLUSIONS

The majority of patients with TSC who are waitlisted for a kidney transplant progress onto transplantation with excellent 1-year post transplant patient and allograft survival.

Clinical practice recommendations for kidney involvement in tuberous sclerosis complex: a consensus statement by the ERKNet Working Group for Autosomal Dominant Structural Kidney Disorders and the ERA Genes & Kidney Working Group

Tuberous sclerosis complex (TSC) is an autosomal dominant disorder characterized by the presence of proliferative lesions throughout the body. Management of TSC is challenging because patients have a multifaceted systemic illness with prominent neurological and developmental impact as well as potentially severe kidney, heart and lung phenotypes; however, every organ system can be involved. Adequate care for patients with TSC requires a coordinated effort involving a multidisciplinary team of clinicians and support staff. This clinical practice recommendation was developed by nephrologists, urologists, paediatric radiologists, interventional radiologists, geneticists, pathologists, and patient and family group representatives, with a focus on TSC-associated kidney manifestations. Careful monitoring of kidney function and assessment of kidney structural lesions by imaging enable early interventions that can preserve kidney function through targeted approaches. Here, we summarize the current evidence and present recommendations for the multidisciplinary management of kidney involvement in TSC.

Tuberous sclerosis complex in adulthood: focus on epilepsy prognosis

OBJECTIVE

Typically diagnosed in early childhood or adolescence, TSC is a chronic, multisystemic disorder with age-dependent manifestations posing a challenge for transition and for specific surveillance throughout the lifetime. Data on the clinical features and severity of TSC in adults and on the prognosis of epilepsy are scarce. We analyzed the clinical and genetic features of a cohort of adult patients with TSC, to identify the prognostic predictors of seizure remission after a long follow-up.

METHOD

We conducted a retrospective analysis of patients diagnosed with TSC according to the updated international diagnostic criteria. Pearson's chi-square or Fisher's exact test and Mann Whitney U test were used to compare variables among the Remission (R) and Non-Remission (NR) group. Univariate and multivariate logistic regression analyses were performed.

RESULTS

We selected 43 patients with TSC and neurological involvement in terms of epilepsy and/or brain lesions, attending the Epilepsy Center of our Institute: of them, 16 (37.2%) were transitioning from the pediatric care and 6 (13.9%) were referred by other specialists. Multiorgan involvement includes cutaneous (86.0%), nephrological (70.7%), hepatic (40.0%), ocular (34.3%), pneumological (28.6%) and cardiac (26.3%) manifestations. Thirty-nine patients (90.7 %) had epilepsy. The mean age at seizure onset was 4 ± 7.3 years: most patients (29, 76.3 %) presented with focal seizures or spasms by age 3 years; only 2 (5.3 %) had seizure onset in adulthood. Twenty-seven patients (69.2 %) experienced multiple seizure types overtime, 23 (59.0 %) had intellectual disability (ID). At last assessment, 14 (35.9 %) were seizure free (R group) and 25 (64.1 %) had drug-resistant seizures (NR group). At logistic regression univariate analysis, ID (OR 7.9, 95 % CI 1.8--34.7), multiple seizure types lifelong (OR 13.2, 95 % CI 2.6- 67.2), spasms/tonic seizures at presentation (OR 6.5, 95 % CI 1.2--35.2), a higher seizure frequency at onset (OR 5.4, 95 % CI 1.2--24.3), abnormal neurological examination (OR 9.8, 95 % CI 1.1--90.6) and pathogenic variants in TSC2 (OR 5.4, 95 % CI 1.2--24.5) were significantly associated with non-remission. In the multivariate analysis, both ID and multiple seizure types lifelong were confirmed as independent predictors of poor seizure outcome.

CONCLUSIONS

In our cohort of adult patients with TSC, epilepsy remains one of the main neurological challenges with only 5.3% of cases manifesting in adulthood. Approximately 64% of these patients failed to achieve seizure remission. ID and multiple seizure types were the main predictors of poor outcome. Nephrological manifestations require continuous specific follow-up in adults.

Patients' and physicians' awareness of clinical symptoms and disease severity in tuberous sclerosis complex

Tuberous sclerosis complex (TSC) is a rare inherited disease with the potential to affect virtually every organ system. Clinical presentation is age- and partly sex-dependent and varies broadly with respect to disease manifestations including treatment-refractory epilepsy, intellectual disability and TSC-associated neuropsychiatric disorders, chronic kidney disease or progressive lung function decline. Given the complexity of this disease, multidisciplinary care in specialized TSC centres is recommended. We aimed to elucidate the state of knowledge of patients/caregivers and physicians on individual disease manifestations. We further examined whether the association to a TSC centre has an impact on the comprehensive consideration of potential disease manifestations. Therefore, a survey was performed in a cohort of German TSC patients and their physicians. Complete information was available for 94 patients with a median age of 18 years [range 1-55] and a sex distribution of 53.2% (male): 48.8% (female). Using almost identical questionnaires for patients/caregivers and their respective physician, there was a good correlation for disease assessments associated with relevant morbidity and mortality like epilepsy, renal angiomyolipoma, cardiac rhabdomyomas or intellectual disability. Correlation was moderate for several neuropsychiatric disorders and only poor for hypomelanotic macules, dental pits or retinal achromic patches. Estimation of overall disease severity using a numeric rating scale correlated highly significantly (Pearson correlation coefficient = 0.767; p < 0.001) between patients/caregivers and physicians. In general, physicians more likely quoted items as 'unknown' than patients (822 answers vs. 435 answers in the respective groups). Questionnaires completed by physicians who were associated with a specialized TSC centre declared a significantly lower proportion of items as unknown (mean 8.7% vs. 20.5%; p < 0.001). These findings indicate that patients treated by specialized TSC centres seem to obtain a more comprehensive surveillance. Furthermore, it shows that there were reasonable surveillance strategies in general and sufficient patient/caregiver interaction and education in the examined cohort. However, for the most prominent disease characteristics there was a good awareness within both the patients/caregivers and the physicians group.

An Autopsy Case of Abdominal Aortic Aneurysm in a Pediatric Decedent With Tuberous Sclerosis Complex

ABSTRACT

Vascular involvement in tuberous sclerosis complex (TSC) is uncommon and even more so in pediatric patients. When asymptomatic, these vascular abnormalities carry increased risk of rupture with increased morbidity and mortality. Here, we describe a case of a ruptured unrecognized abdominal aortic aneurysm in an 11-month-old patient with a history of TSC. The abdominal aortic aneurysm was discovered at autopsy and highlights the rarity of abdominal aortic aneurysm in pediatric patients diagnosed with TSC and the importance of screening for associated aneurysmal disease in the pediatric population with TSC. Furthermore, the extensive retroperitoneal hemorrhage seen in this case also highlights a rare but potential mimic of abuse in the pediatric population.

Effectiveness and safety of everolimus treatment in patients with tuberous sclerosis complex in real-world clinical practice

BACKGROUND

The randomised double-blinded placebo-controlled EXIST-1-3 studies have showed everolimus effective with adverse effects reported as acceptable in treatment of symptoms in patients with tuberous sclerosis complex (TSC), although evidence of outcomes in clinical practice remains limited. This study aimed to investigate, in clinical practice, the effectiveness and safety of everolimus for epilepsy, renal angiomyolipoma (rAML), and subependymal giant cell astrocytoma (SEGA) in patients with TSC.

RESULTS

The study included 64 patients with TSC (median age: 19, range 0.9-54 years) receiving everolimus treatment (Norway: n = 35; Denmark: n = 29). Among 45 patients with epilepsy, 14 (31%) were responders experiencing ≥ 50% reduction in seizure frequency in the last 3 months of treatment compared with the last 3 months before treatment. Nineteen (42%) patients changed their anti-seizure medications (ASMs). Responders were more common among patients < 18 years (46%) than among patients ≥ 18 years (14%, p = 0.03). In 29 patients with rAML, everolimus reduced (≥ 30% decrease) and stabilized (< 20% increase, ≤ 30% decrease) longest diameter of rAML in 38% and 59%, respectively, after a mean treatment duration of 37 months. SEGA volume was reduced in three patients by 71%, 43%, and 48% after 39, 34, and 82 months. Adverse effects were reported in 61 of 64 patients (95%) after a median treatment duration of 31 months (range 0-106), with oral ulceration/stomatitis (63%) and upper respiratory tract infections (38%) being the most common. The most common laboratory abnormalities were increased cholesterol (41%), anaemia (30%), and leucopoenia (25%). Grade 3-4 adverse effects were reported in 36% of cases, and life-threatening conditions were reported in two patients. Nine patients discontinued everolimus treatment.

CONCLUSIONS

Seizure reduction in this study sample was consistent with results from EXIST, but might be lower than expected, given that changes in concomitant ASMs are part of clinical practice. Seizure reduction was associated with younger age. As with EXIST, everolimus reduced or stabilised rAML size in most patients. SEGA volume was reduced in all three patients. Close follow-up is needed for this group, especially for children and patients who may not be able to report adverse effects.

Recurrent symptomatic aortic aneurysm in a young girl with tuberous sclerosis complex and review of the literature

An abdominal aortic aneurysm is a rare occurrence in pediatric populations. When present, it is usually associated with an underlying etiology such as a connective tissue disorder, inflammatory process, or noninflammatory medial degeneration. In the present report, we describe the case of a girl with tuberous sclerosis complex who underwent successful emergency open repair of a symptomatic infrarenal abdominal aortic aneurysm and recurrent type IV thoracoabdominal aortic aneurysm.

Cystic kidney disease in tuberous sclerosis complex: current knowledge and unresolved questions

Tuberous sclerosis complex (TSC) is an autosomal dominant disorder with an estimated incidence of one in 5000 to 10,000 live births worldwide. Two million people of all races and genders are estimated to have TSC secondary to mutations in one of two tumor suppressor genes, TSC1 or TSC2. The respective TSC1 and 2 gene products - hamartin and tuberin - form cytoplasmic heterodimers that inhibit mTOR-mediated cell growth and division. When mTOR inhibition is lost, people with TSC develop characteristic and usually benign tumors in various organ systems. Kidney tumors and cysts are common, particularly in the setting of TSC2 gene mutations. In most TSC patients, the number of kidney cysts is limited, their morphology is simple, their size is small, and their clinical significance is negligible. In some, cyst morphology progresses from simple to complex with the risk of malignant transformation. In others, aggressive accumulation and growth of kidney cysts can cause hypertension, impaired kidney function, and progression to kidney failure. This educational review summarizes current knowledge and remaining open questions regarding cystic kidney disease in TSC, emphasizing detection, classification, surveillance, and treatment options.

Cutaneous Manifestations and Neurological Diseases

Our skin and nervous system are tightly connected. Numerous dermatomes on our skin provide sensory information to the brain. Because skin changes can occasionally be the first sign of a neurological problem, understanding skin alterations is crucial as it can indicate early about the underlying condition, which can affect the prognosis of the disease. In these cases, the dermatologists' and neurologists' skills are complementary to each other. In this article, we have categorized diseases with neuro-cutaneous manifestations under different headings, such as infections, metabolic diseases, connective tissue disorders, genodermatoses, nutritional deficiency, and the diagnostic criteria of some commonly encountered diseases. Through tabulation, it has been observed that this categorization can serve as a useful reference for managing day-to-day patients who are either diagnosed with the diseases mentioned above or suspected to have the conditions.

Paradigm shift in the treatment of tuberous sclerosis: Effectiveness of everolimus

Tuberous sclerosis complex (TSC) is an autosomal dominant disease characterised by abnormal cell proliferation and differentiation that affects multiple organs and can lead to the growth of hamartomas. Tuberous sclerosis complex is caused by the disinhibition of the protein mTOR (mammalian target of rapamycin). In the past, various therapeutic approaches, even if only symptomatic, have been attempted to improve the clinical effects of this disease. While all of these therapeutic strategies are useful and are still used and indicated, they are symptomatic therapies based on the individual symptoms of the disease and therefore not fully effective in modifying long-term outcomes. A new therapeutic approach is the introduction of allosteric inhibitors of mTORC1, which allow restoration of metabolic homeostasis in mutant cells, potentially eliminating most of the clinical manifestations associated with Tuberous sclerosis complex. Everolimus, a mammalian target of the rapamycin inhibitor, is able to reduce hamartomas, correcting the specific molecular defect that causes Tuberous sclerosis complex. In this review, we report the findings from the literature on the use of everolimus as an effective and safe drug in the treatment of TSC manifestations affecting various organs, from the central nervous system to the heart.

Rapamycin and rapalogs for tuberous sclerosis complex

BACKGROUND

Potential benefits of rapamycin or rapalogs for treating people with tuberous sclerosis complex (TSC) have been shown. Currently everolimus (a rapalog) is only approved for TSC-associated renal angiomyolipoma and subependymal giant cell astrocytoma (SEGA), but not other manifestations of TSC. A systematic review needs to establish evidence for rapamycin or rapalogs for various manifestations in TSC. This is an updated review.

OBJECTIVES

To determine the effectiveness of rapamycin or rapalogs in people with TSC for decreasing tumour size and other manifestations and to assess the safety of rapamycin or rapalogs in relation to their adverse effects.

SEARCH METHODS

We identified relevant studies from the Cochrane-Central-Register-of-Controlled-Trials (CENTRAL), Ovid MEDLINE and ongoing trials registries with no language restrictions. We searched conference proceedings and abstract books of conferences. Date of the last searches: 15 July 2022.

SELECTION CRITERIA

Randomised controlled trials (RCTs) or quasi-RCTs of rapamycin or rapalogs in people with TSC.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed the risk of bias of each study; a third review author verified the extracted data and risk of bias decisions. We assessed the certainty of the evidence using GRADE.

MAIN RESULTS

The current update added seven RCTs, bringing the total number to 10 RCTs (with 1008 participants aged 3 months to 65 years; 484 males). All TSC diagnoses were by consensus criteria as a minimum. In parallel studies, 645 participants received active interventions and 340 placebo. Evidence is low-to-high certainty and study quality is mixed; mostly a low risk of bias across domains, but one study had a high risk of performance bias (lack of blinding) and three studies had a high risk of attrition bias. Manufacturers of the investigational products supported eight studies. Systemic administration Six studies (703 participants) administered everolimus (rapalog) orally. More participants in the intervention arm reduced renal angiomyolipoma size by 50% (risk ratio (RR) 24.69, 95% confidence interval (CI) 3.51 to 173.41; P = 0.001; 2 studies, 162 participants, high-certainty evidence). In the intervention arm, more participants in the intervention arm reduced SEGA tumour size by 50% (RR 27.85, 95% CI 1.74 to 444.82; P = 0.02; 1 study; 117 participants; moderate-certainty evidence) ,and reported more skin responses (RR 5.78, 95% CI 2.30 to 14.52; P = 0.0002; 2 studies; 224 participants; high-certainty evidence). In one 18-week study (366 participants), the intervention led to 25% fewer seizures (RR 1.63, 95% CI 1.27 to 2.09; P = 0.0001) or 50% fewer seizures (RR 2.28, 95% CI 1.44 to 3.60; P = 0.0004); but there was no difference in numbers being seizure-free (RR 5.30, 95% CI 0.69 to 40.57; P = 0.11) (moderate-certainty evidence). One study (42 participants) showed no difference in neurocognitive, neuropsychiatry, behavioural, sensory and motor development (low-certainty evidence). Total adverse events (AEs) did not differ between groups (RR 1.09, 95% CI 0.97 to 1.22; P = 0.16; 5 studies; 680 participants; high-certainty evidence). However, the intervention group experienced more AEs resulting in withdrawal, interruption of treatment, or reduced dose (RR 2.61, 95% CI 1.58 to 4.33; P = 0.0002; 4 studies; 633 participants; high-certainty evidence and also reported more severe AEs (RR 2.35, 95% CI 0.99 to 5.58; P = 0.05; 2 studies; 413 participants; high-certainty evidence). Topical (skin) administration Four studies (305 participants) administered rapamycin topically. More participants in the intervention arm showed a response to skin lesions (RR 2.72, 95% CI 1.76 to 4.18; P < 0.00001; 2 studies; 187 participants; high-certainty evidence) and more participants in the placebo arm reported a deterioration of skin lesions (RR 0.27, 95% CI 0.15 to 0.49; 1 study; 164 participants; high-certainty evidence). More participants in the intervention arm responded to facial angiofibroma at one to three months (RR 28.74, 95% CI 1.78 to 463.19; P = 0.02) and three to six months (RR 39.39, 95% CI 2.48 to 626.00; P = 0.009; low-certainty evidence). Similar results were noted for cephalic plaques at one to three months (RR 10.93, 95% CI 0.64 to 186.08; P = 0.10) and three to six months (RR 7.38, 95% CI 1.01 to 53.83; P = 0.05; low-certainty evidence). More participants on placebo showed a deterioration of skin lesions (RR 0.27, 95% CI 0.15 to 0.49; P < 0.0001; 1 study; 164 participants; moderate-certainty evidence). The intervention arm reported a higher general improvement score (MD -1.01, 95% CI -1.68 to -0.34; P < 0.0001), but no difference specifically in the adult subgroup (MD -0.75, 95% CI -1.58 to 0.08; P = 0.08; 1 study; 36 participants; moderate-certainty evidence). Participants in the intervention arm reported higher satisfaction than with placebo (MD -0.92, 95% CI -1.79 to -0.05; P = 0.04; 1 study; 36 participants; low-certainty evidence), although again with no difference among adults (MD -0.25, 95% CI -1.52 to 1.02; P = 0.70; 1 study; 18 participants; low-certainty evidence). Groups did not differ in change in quality of life at six months (MD 0.30, 95% CI -1.01 to 1.61; P = 0.65; 1 study; 62 participants; low-certainty evidence). Treatment led to a higher risk of any AE compared to placebo (RR 1.72, 95% CI 1.10, 2.67; P = 0.02; 3 studies; 277 participants; moderate-certainty evidence); but no difference between groups in severe AEs (RR 0.78, 95% CI 0.19 to 3.15; P = 0.73; 1 study; 179 participants; moderate-certainty evidence).

AUTHORS' CONCLUSIONS

Oral everolimus reduces the size of SEGA and renal angiomyolipoma by 50%, reduces seizure frequency by 25% and 50% and implements beneficial effects on skin lesions with no difference in the total number of AEs compared to placebo; however, more participants in the treatment group required a dose reduction, interruption or withdrawal and marginally more experienced serious AEs compared to placebo. Topical rapamycin increases the response to skin lesions and facial angiofibroma, an improvement score, satisfaction and the risk of any AE, but not severe adverse events. With caution regarding the risk of severe AEs, this review supports oral everolimus for renal angiomyolipoma, SEGA, seizure, and skin lesions, and topical rapamycin for facial angiofibroma.

Tuberous Sclerosis Complex Kidney Lesion Pathogenesis: A Developmental Perspective

The phenotypic diversity of tuberous sclerosis complex (TSC) kidney pathology is enigmatic. Despite a well-established monogenic etiology, an incomplete understanding of lesion pathogenesis persists. In this review, we explore the question: How do TSC kidney lesions arise? We appraise literature findings in the context of mutational timing and cell-of-origin. Through a developmental lens, we integrate the critical results from clinical studies, human specimens, and genetic animal models. We also review novel insights gleaned from emerging organoid and single-cell sequencing technologies. We present a new model of pathogenesis which posits a phenotypic continuum, whereby lesions arise by mutagenesis during development from variably timed second-hit events. This model can serve as a conceptual framework for testing hypotheses of TSC lesion pathogenesis, both in the kidney and in other affected tissues.

Everolimus as a therapeutic option in refractory epilepsy in children with tuberous sclerosis: a systematic review

BACKGROUND

 Tuberous sclerosis (TS) is a multisystem genetic disease in which epilepsy is a frequent manifestation and is often difficult to control. Everolimus is a drug with proven efficacy in the treatment of other conditions related to TS, and some evidence suggests that its use benefits the treatment of refractory epilepsy in these patients.

OBJECTIVE

 To evaluate the efficacy of everolimus in controlling refractory epilepsy in children with TS.

METHODS

 A literature review was conducted in the Pubmed, BVS, and Medline databases, using the descriptors Tuberous sclerosis, Children, Epilepsy, and Everolimus. Original clinical trials and prospective studies published in Portuguese or English in the last decade that evaluated the use of everolimus as an adjuvant therapy in the control of refractory epilepsy in pediatric patients with TS were included.

RESULTS

 Our search screened 246 articles from electronic databases, 6 of which were chosen for review. Despite the methodological variations between the studies, most patients benefited from the use of everolimus to control refractory epilepsy, with response rates ranging from 28.6 to 100%. Adverse effects were present in all studies leading to dropouts of some patients; however, the majority were of low severity.

CONCLUSION

 The selected studies suggest a beneficial effect of everolimus in the treatment of refractory epilepsy in children with TS, despite the adverse effects observed. Further studies involving a larger sample in double-blind controlled clinical trials should be performed to provide more information and statistical credibility.

Reprint of: lessons from histopathologic examination of nephrectomy specimens in patients with tuberous sclerosis complex: cysts, angiomyolipomas & renal cell carcinoma

Renal manifestations in patients with tuberous sclerosis complex (TSC) include cysts, angiomyolipoma, and renal cell carcinoma. Unlike many hereditary predisposition syndromes, the spectrum of renal tumors in TSC patients (including both angiomyolipoma and renal cell carcinoma) is broad, with significant morphologic heterogeneity. An improved understanding of histopathologic findings in TSC patients and associated clinicopathologic correlates has significant implications not just in establishing a diagnosis of TSC, but also in the recognition of sporadic tumors occurring secondary to somatic alterations of TSC1/TSC2/MTOR pathway genes and accurate prognostication. In this review, we have discussed issues relevant to clinical management based on histopathologic findings in nephrectomy specimens from patients with TSC. This includes discussions related to screening for TSC, diagnosis of PKD1/TSC2 contiguous gene deletion syndrome, the morphologic spectrum of angiomyolipoma and renal epithelium-derived neoplasia, including the risk of disease progression.

Incidental finding of tuberous sclerosis complex in a woman with hematuria: A case report of renal angiomyolipoma and review of the literature

Tuberous sclerosis complex (TSC) is a rare genetic multisystem disorder that was first described by Von Recklinghausen. We describe a case of a female, who initially presented with hematuria and was later found to have multiple manifestations of the disease. The report emphasizes the value of investigations on suspected cases.

Progress in Tuberous Sclerosis Complex Renal Disease

Tuberous sclerosis complex (TSC) is an autosomal dominant disorder that affects both fetal development and postnatal tissue growth, resulting in altered brain structures and a tumor predisposition syndrome. Although every organ system is affected by the disease, kidney involvement is a leading cause of death in adults with TSC. Over the past decade, significant progress has been made in understanding the renal disease. This review focuses on the cystic and solid renal lesions in TSC, including their pathobiology and treatment.

Subependymal Giant Cell Astrocytomas in Tuberous Sclerosis Complex-Current Views on Their Pathogenesis and Management

Introduction, Tuberous sclerosis complex (TSC) is an autosomal-dominant disorder caused by mutations inactivating TSC1 or TSC2 genes and characterized by the presence of tumors involving many organs, including the brain, heart, kidneys, and skin. Subependymal giant cell astrocytoma (SEGA) is a slow-growing brain tumor almost exclusively associated with TSC.

STATE OF THE ART

Despite the fact that SEGAs are benign, they require well-considered decisions regarding the timing and modality of pharmacological or surgical treatment. In TSC children and adolescents, SEGA is the major cause of mortality and morbidity.

CLINICAL IMPLICATIONS

Until recently, surgical resection has been the standard therapy for SEGAs but the discovery of the role of the mTOR pathway and the introduction of mTOR inhibitors to clinical practice changed the therapeutic landscape of these tumors. In the current paper, we discuss the pros and cons of mTOR inhibitors and surgical approaches in SEGA treatment.

FUTURE DIRECTIONS

In 2021, the International Tuberous Sclerosis Complex Consensus Group proposed a new integrative strategy for SEGA management. In the following review, we discuss the proposed recommendations and report the results of the literature search for the latest treatment directions.

UPLC-MS based integrated plasma proteomic and metabolomic profiling of TSC-RAML and its relationship with everolimus treatment

Aim: To profile the plasma proteomics and metabolomics of patients with renal cysts, sporadic angiomyolipoma (S-AML) and tuberous sclerosis complex related angiomyolipoma (TSC-RAML) before and after everolimus treatment, and to find potential diagnostic and prognostic biomarkers as well as reveal the underlying mechanism of TSC tumorigenesis. Materials and Methods: We retrospectively measured the plasma proteins and metabolites from November 2016 to November 2017 in a cohort of pre-treatment and post-treatment TSC-RAML patients and compared them with renal cyst and S-AML patients by ultra-performance liquid chromatography-mass spectrometer (UPLC-MS). The tumor reduction rates of TSC-RAML were assessed and correlated with the plasma protein and metabolite levels. In addition, functional analysis based on differentially expressed molecules was performed to reveal the underlying mechanisms. Results: Eighty-five patients with one hundred and ten plasma samples were enrolled in our study. Multiple proteins and metabolites, such as pre-melanosome protein (PMEL) and S-adenosylmethionine (SAM), demonstrated both diagnostic and prognostic effects. Functional analysis revealed many dysregulated pathways, including angiogenesis synthesis, smooth muscle proliferation and migration, amino acid metabolism and glycerophospholipid metabolism. Conclusion: The plasma proteomics and metabolomics pattern of TSC-RAML was clearly different from that of other renal tumors, and the differentially expressed plasma molecules could be used as prognostic and diagnostic biomarkers. The dysregulated pathways, such as angiogenesis and amino acid metabolism, may shed new light on the treatment of TSC-RAML.

Lessons from histopathologic examination of nephrectomy specimens in patients with tuberous sclerosis complex: cysts, angiomyolipomas, and renal cell carcinoma

Renal manifestations in patients with tuberous sclerosis complex (TSC) include cysts, angiomyolipoma, and renal cell carcinoma. Unlike many hereditary predisposition syndromes, the spectrum of renal tumors in TSC patients (including both angiomyolipoma and renal cell carcinoma) is broad, with significant morphologic heterogeneity. An improved understanding of histopathologic findings in TSC patients and associated clinicopathologic correlates has significant implications not just in establishing a diagnosis of TSC, but also in the recognition of sporadic tumors occurring secondary to somatic alterations of TSC1/TSC2/MTOR pathway genes and accurate prognostication. In this review, we have discussed issues relevant to clinical management based on histopathologic findings in nephrectomy specimens from patients with TSC. This includes discussions related to screening for TSC, diagnosis of PKD1/TSC2 contiguous gene deletion syndrome, the morphologic spectrum of angiomyolipoma and renal epithelium-derived neoplasia, including the risk of disease progression.

Renal Transcriptome and Metabolome in Mice with Principal Cell-Specific Ablation of the Tsc1 Gene: Derangements in Pathways Associated with Cell Metabolism, Growth and Acid Secretion

Tuberous sclerosis complex (TSC) is caused by mutations in the hamartin (TSC1) or tuberin (TSC2) genes. Using a mouse model of TSC renal cystogenesis that we have previously described, the current studies delineate the metabolic changes in the kidney and their relation to alterations in renal gene expression. To accomplish this, we compared the metabolome and transcriptome of kidneys from 28-day-old wildtype (Wt) and principal cell-specific Tsc1 KO (Tsc1 KO) mice using targeted ¹H nuclear magnetic resonance targeted metabolomic and RNA-seq analyses. The significant changes in the kidney metabolome of Tsc1 KO mice included reductions in the level of several amino acids and significant decreases in creatine, NADH, inosine, UDP-galactose, GTP and myo-inositol levels. These derangements may affect energy production and storage, signal transduction and synthetic pathways. The pertinent derangement in the transcriptome of Tsc1 KO mice was associated with increased collecting duct acid secretion, active cell division and the up-regulation of signaling pathways (e.g., MAPK and AKT/PI3K) that suppress the TSC2 GTPase-activating function. The combined renal metabolome and transcriptome alterations observed in these studies correlate with the unregulated growth and predominance of genotypically normal A-intercalated cells in the epithelium of renal cysts in Tsc1 KO mice.

Subependymal giant-cell astrocytoma: a surgical review in the modern era of mTOR inhibitors

INTRODUCTION

Surgical removal has been the historical treatment for subependymal giant-cell astrocytoma (SEGA) in tuberous sclerosis complex (TSC) patients. In the past decade, mTOR inhibitors have shown efficacy in the treatment of SEGA, significantly reducing tumor size. The aim of this study was to assess the safety and efficacy of surgical treatment at a time when mTOR inhibitors have changed standard treatment.

MATERIAL AND METHODS

We conducted a single-center retrospective study including all patients treated by surgery for SEGA from October 2003 to September 2019, with a review of all SEGA surgical case series, following PRISMA guidelines. Research focused on demographics, surgical indications, surgical approach, use of CSF shunt, morbidity and mortality, resection quality, recurrence rate and treatment of recurrence, follow-up and long-term clinical status.

RESULTS

Eleven patients were included, with a median age at surgery of 16.0 years. Gross total resection was achieved in 8 patients (72%), with no permanent morbidity. One patient needed further surgery for tumor recurrence. Eighteen studies were reviewed, totaling 263 TSC patients affected by SEGA and 286 surgical procedures. Gross total resection was achieved in 81.1% of cases, mortality was 4.9% and permanent morbidity 6.1%. Tumor recurrence occurred in 11.5% of cases, and was secondary to partial tumor resection at first surgery in the majority of cases.

CONCLUSION

Surgical treatment of SEGA is still a valid and effective option. Morbidity is low and complete disappearance of SEGA can be achieved in selected cases.

Popliteal artery aneurysm in a 14-year-old boy with tuberous sclerosis complex

Tuberous sclerosis complex (TSC) is rarely associated with aneurysms. We have described a patient with a popliteal artery aneurysm that was associated with TSC and occlusion of the right posterior tibial artery. The patient underwent aneurysm resection and vein graft replacement, with an uneventful postoperative course and no recurrence at 11 months of follow-up. Patients with TSC could have aneurysms in areas that will not be recognized on abdominal imaging. Physical examination of the lower extremities should be performed owing to the possibility of a popliteal artery aneurysm, and imaging studies should be performed if an aneurysm is suspected.

Renal organoid modeling of tuberous sclerosis complex reveals lesion features arise from diverse developmental processes

Tuberous sclerosis complex (TSC) is a multisystem tumor-forming disorder caused by loss of TSC1 or TSC2. Renal manifestations predominately include cysts and angiomyolipomas. Despite a well-described monogenic etiology, the cellular pathogenesis remains elusive. We report a genetically engineered human renal organoid model that recapitulates pleiotropic features of TSC kidney disease in vitro and upon orthotopic xenotransplantation. Time course single-cell RNA sequencing demonstrates that loss of TSC1 or TSC2 affects multiple developmental processes in the renal epithelial, stromal, and glial compartments. First, TSC1 or TSC2 ablation induces transitional upregulation of stromal-associated genes. Second, epithelial cells in the TSC1^-/- and TSC2^-/- organoids exhibit a rapamycin-insensitive epithelial-to-mesenchymal transition. Third, a melanocytic population forms exclusively in TSC1^-/- and TSC2^-/- organoids, branching from MITF⁺ Schwann cell precursors. Together, these results illustrate the pleiotropic developmental consequences of biallelic inactivation of TSC1 or TSC2 and offer insight into TSC kidney lesion pathogenesis.

Blood pressure and glomerular filtration rate in youth with tuberous sclerosis complex

Renal involvement is very common in tuberous sclerosis complex (TSC) and is characterized by the development of angiomyolipoma and cysts. The aims of the present study were to assess kidney function and clinical features of renal involvement in TSC, including kidney function and blood pressure (BP) levels in children, adolescents and young adults. Non-selected patients with a definite diagnosis of TSC attending the paediatric neurology outpatient department of a tertiary hospital were included in a cross-sectional study. All participants had a renal imaging study within 6 months of ambulatory blood pressure (BP) and glomerular filtration rate (GFR) assessment. Data on demographics, history, genotype, kidney function at diagnosis and last imaging were collected. Twenty patients were enrolled in this study with a median age of 15 years (IQR range 9 to 18). About 23.5% of the participants had ambulatory hypertension. Systolic BP levels correlated significantly with GFR_DTPA values despite the absence of hyperfiltration. Patients that developed hypertension and possibly those with angiomyolipoma or cysts had higher GFR levels in childhood and adolescence. All the patients with ambulatory hypertension had angiomyolipoma or cysts on renal imaging studies.

CONCLUSIONS

Hypertension may present with increased frequency in young patients with kidney disease associated with TSC. Routine ambulatory BP measurement should be part of the annual clinical assessment in patients with TSC.

WHAT IS KNOWN

• Nearly half of the patients with TSC have a premature decline in their renal function in their fifth decade of life. • Hypertension and hyperfiltration have been proposed as modifiable factors of progression of renal decline in patients with TSC-related renal disease.

WHAT IS NEW

• Hypertension is prevalent in youth with tuberous sclerosis complex. • SBP levels have a positive relation with GFR levels within the normal range of GFRDTPA values.

Genotype-phenotype correlation of renal lesions in the tuberous sclerosis complex

Tuberous sclerosis complex (TSC) is an autosomal dominant disease caused by loss-of-function mutations in either of two tumor suppressor genes, TSC1 and TSC2. These mutations lead to the growth of benign tumors and hamartomas in many organs, including those of the central nervous system, the skin, and the kidneys. To investigate the genotype-phenotype correlation, we performed sequence analysis of the TSC1/2 genes using next-generation sequencing. We classified 30 patients with TSC whose pathogenic variants were identified into two groups: those with mutations producing premature termination codons (PTCs) and those with missense mutations. Then, we compared the phenotypes between the two groups. Patients with a PTC were significantly more likely to manifest the major symptoms of the diagnostic criteria than those without a PTC (P = 0.035). The frequencies of subependymal nodules (P = 0.026), cortical tubers (P = 0.026), and renal cysts (P = 0.026) were significantly higher in PTC-containing variants than in cases without a PTC. When the analyses were limited to renal angiomyolipoma (AML) cases with TSC2 mutations, there was no difference in tumor size between cases with and without a PTC. However, the cases with a PTC showed a trend toward disease onset at a younger age and multiple tumors, and bilateral disease was observed in their AML lesions. TSC patients with PTC-producing mutations might potentially manifest more severe TSC phenotypes than those with missense mutations. A larger-scale study with appropriate samples deserves further investigation.

Racial differences in the dermatological manifestations of tuberous sclerosis complex and the potential effects on diagnosis and care

Background

Tuberous sclerosis complex (TSC) is an autosomal dominant neurocutaneous disorder of non-malignant tumor growths throughout major organ systems and neurological, neuropsychiatric, renal, and pulmonary co-morbidities. Skin manifestations are readily visible, often develop early in life, and are major features that contribute to TSC diagnosis. Medical photographs of such manifestations are commonly shown as examples from White individuals creating a potential barrier to accurately identifying these features in darker skinned individuals.

Objectives

The aim of this report is to raise awareness of dermatological manifestations associated with TSC, compare their appearance by race, and consider how recognition of these features could impact diagnosis and treatment of TSC.

Design and Methods

We conducted a retrospective chart review at the TSC Center of Excellence (TSCOE) at the Kennedy Krieger Institute, which included all patients in the center from 2009 (inception) through the end of the calendar year 2015 and analyzed data from the TSC Alliance Natural History Database (NHD).

Results

Among TSCOE patients, 50% of Black patients were diagnosed before the age of 1 year, compared with 70% of White patients. NHD data corroborated this trend showing a significant difference with only 38% of Blacks as compared with 50% of Whites were diagnosed at age ⩽1 year. A significant difference was observed where White participants had higher odds of having received genetic testing in both data sets. While no differences in the total number of TSC features was observed in either data set, shagreen patches and cephalic fibrous plaques were more frequently recorded in the NHD for Black individuals.

Conclusion

We highlight a disparity in the representation of Black participants within the NHD, TSCOE, and TSC trials, in addition to differences in utilization of molecular testing and topical mechanistic target of rapamycin (mTOR) inhibitor therapy between Black and White individuals. We show a trend toward later diagnosis age in Black individuals. These differences between races warrant further study across additional clinical sites and other minority groups.

Endovascular Repair of a Descending Thoracic Aortic Aneurysm in a Pediatric Patient with Tuberous Sclerosis: A Case Report and Review of the Literature

Aortic aneurysm in children is rare, but has been described in the tuberous sclerosis complex (TSC) population. While surgical repair has been utilized as the primary means of intervention, we present the first known case reporting exclusion of a descending thoracic aortic aneurysm with percutaneous covered stent implantation in a pediatric patient with TSC. A review of the literature is also included herein.

Adults with tuberous sclerosis complex: A distinct patient population

OBJECTIVES

There are few data on adults living with tuberous sclerosis complex (TSC), with most studies focusing on pediatric populations. The objective of our study was to examine a large national cohort of adults with TSC, and to describe the clinical characteristics of these adults and the nature of the multidisciplinary care that they receive.

METHODS

Six Canadian medical centers collaborated in this study. Data were collected using a standardized form, and descriptive statistics were used for the analyses.

RESULTS

Our study included 181 adults with definite TSC (mean age = 33.6 years [SD = 13.7]). More than 40% (n = 75) had family members affected by TSC. Forty-six percent (n = 83) of individuals had intellectual disability. Nearly 30% (n = 52) of individuals reported living alone or with a partner/spouse. Seventy-six percent (n = 138) of people had epilepsy, 43% (n = 59) of whom had drug-resistant epilepsy, and 21% (n = 29) had undergone epilepsy surgery. Neuropsychiatric disease (n = 128) and renal angiomyolipomas (n = 130) were both present in approximately 70% of people. Renal imaging was performed in 75.7% (n = 137) of participants within the past 3 years. Renal and pulmonary function tests, as well as electrocardiograms, were recently performed in a minority of individuals.

SIGNIFICANCE

Our cohort of adults with TSC showed that an important proportion have a milder phenotype, and are more frequently familial, as compared to children with TSC (and differing from prior reports in adult cohorts). Drug-resistant epilepsy, neuropsychiatric comorbidities, and renal angiomyolipoma are challenging factors in adults with TSC. Our participating medical centers generally followed recommended screening strategies, but there remain important gaps in care. Multidisciplinary and structured TSC care centers offering service to adults may help to improve the health of this important patient population.

Interleukin-6 mediates PSAT1 expression and serine metabolism in TSC2-deficient cells

Tuberous sclerosis complex (TSC) and lymphangioleiomyomatosis (LAM) are caused by aberrant mechanistic Target of Rapamycin Complex 1 (mTORC1) activation due to loss of either TSC1 or TSC2 Cytokine profiling of TSC2-deficient LAM patient-derived cells revealed striking up-regulation of Interleukin-6 (IL-6). LAM patient plasma contained increased circulating IL-6 compared with healthy controls, and TSC2-deficient cells showed up-regulation of IL-6 transcription and secretion compared to wild-type cells. IL-6 blockade repressed the proliferation and migration of TSC2-deficient cells and reduced oxygen consumption and extracellular acidification. U-¹³C glucose tracing revealed that IL-6 knockout reduced 3-phosphoserine and serine production in TSC2-deficient cells, implicating IL-6 in de novo serine metabolism. IL-6 knockout reduced expression of phosphoserine aminotransferase 1 (PSAT1), an essential enzyme in serine biosynthesis. Importantly, recombinant IL-6 treatment rescued PSAT1 expression in the TSC2-deficient, IL-6 knockout clones selectively and had no effect on wild-type cells. Treatment with anti-IL-6 (αIL-6) antibody similarly reduced cell proliferation and migration and reduced renal tumors in Tsc2 ^+/- mice while reducing PSAT1 expression. These data reveal a mechanism through which IL-6 regulates serine biosynthesis, with potential relevance to the therapy of tumors with mTORC1 hyperactivity.

Tuberous Sclerosis: Current Update

Tuberous sclerosis complex (TSC) is a relatively rare autosomal dominant neurocutaneous disorder secondary to mutations in the TSC1 or TSC2 tumor suppressor genes. Although manifestation of the classic triad of seizures, intellectual disability, and facial angiofibromas may facilitate timely diagnosis of TSC, the multisystem features that may indicate TSC in the absence of these manifestations remain highly variable. In addition, patients with TSC are at risk of developing multiple benign and malignant tumors in various organ systems, resulting in increased morbidity and mortality. Thus, imaging plays a critical role in diagnosis, surveillance, and management of patients with TSC. It is crucial that radiologists be familiar with TSC and the various associated imaging features to avoid a delayed or incorrect diagnosis. Key manifestations include cortical dysplasias, subependymal nodules, subependymal giant cell astrocytomas, cardiac rhabdomyomas, lymphangioleiomyomatosis, and angiomyolipomas. Renal angiomyolipomas in particular can manifest with imaging features that mimic renal malignancy and pose a diagnostic dilemma. Other manifestations include dermatologic and ophthalmic manifestations, renal cysts, renal cell carcinomas, multifocal micronodular pneumocyte hyperplasia, splenic hamartomas, and other rare tumors such as perivascular epithelioid tumors. In addition to using imaging and clinical features to confirm the diagnosis, genetic testing can be performed. In this article, the molecular pathogenesis, clinical manifestations, and imaging features of TSC are reviewed. Current recommendations for management and surveillance of TSC are discussed as well. ^©RSNA, 2021.

Renal cystic disease in tuberous sclerosis complex

Tuberous sclerosis complex (TSC) is associated with TSC1 or TSC2 gene mutations resulting in hyperactivation of the mTORC1 pathway. This mTORC1 activation is associated with abnormal tissue development and proliferation such that in the kidney there are both solid tumors and cystic lesions. This review summarizes recent advances in tuberous sclerosis complex nephrology and focuses on the genetics and cell biology of tuberous sclerosis complex renal disease, highlighting a role of extracellular vesicles and the innate immune system in disease pathogenesis.

A population-based study to estimate survival and standardized mortality of tuberous sclerosis complex (TSC) in Taiwan

Background

Tuberous sclerosis complex (TSC) is an autosomal dominant disease with systemic manifestations, which can cause significant mortality and morbidity. Population-based epidemiological studies on TSC mortality and survival remain scarce, though several recent studies provide evidence that TSC survival rates are high and disease prognosis is fair for most patients. This study aims to estimate the life expectancy and mortality statistics in Taiwanese TSC patients, investigate prognosis and associations of TSC mortality based on demographic variables, and compare these results to past literature, especially for Asian patients.

Methods

Taiwanese National Health Insurance (NHI) insurees can obtain Catastrophic Illness Certificates (CIC) for certain eligible diseases to waive copayments after diagnosis by two independent physicians. CIC holders for TSC during 1997–2010 were identified from the NHI Research Database. Queries on enrollment (CIC acquisition) age, endpoint (end of query period or death) age, sex, and comorbidities were obtained. Patients were separated into cohorts (endpoint age, sex, and age of diagnosis), and analyzed accordingly.

Results

471 patients (232 male, 239 female) were identified, of which 14 died. Compared to literature, patients showed similar demographics (age range, diagnosis age, sex distribution); similar manifestations and prevalence (epilepsy, intellectual disability, renal disease); lower disease prevalence (1 in 63,290); lower mortality (0.21% per year); and near-identical standardized mortality ratio (4.99). A cumulative mortality of 4.08% was found over 14 years, though mortality plateaued at 7 years post-enrollment, suggesting a good overall survival rate; comparable with previous studies in Asian patients. Enrollment age was a significant prognostic factor, with late-enrollment (age > 18) patients at higher risk for all-cause mortality (Hazard ratio = 6.54). Average remaining lifetime was significantly lower than the general population, and decreased with age.

Conclusions

This study reports a population-based disease database, highlights the importance of diagnosis age in prognosis prediction, and suggests the role of renal manifestations in mortality. Furthermore, it corroborates recent TSC studies in the Asian population in terms of survival. Overall, physician vigilance, early diagnosis, and careful monitoring are beneficial for disease outcome and patient survival.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13023-021-01974-3.

Everolimus versus sirolimus for angiomyolipoma associated with tuberous sclerosis complex: a multi-institutional retrospective study in China

Purpose

To evaluate the efficacy and safety of everolimus and sirolimus in patients with tuberous sclerosis complex-associated angiomyolipomas (TSC-AML).

Materials and methods

We performed a multi-institutional retrospective study of TSC-AML patients treated with oral everolimus 10 mg or sirolimus 2 mg per day for at least 3 months. Angiomyolipoma volume was estimated using orthogonal measurements by MRI or CT. Adverse events (AEs) were assessed according to the National Cancer Institute Common Terminology Criteria for Adverse Events. All analyses were performed using SPSS 19.0 software.

Results

Response rates were high in both groups. With the prolonged medication durations, the therapeutic efficacy of both agents became more significant. The TSC-AML volume reduction after 6 and 12 months was more pronounced in patients with everolimus than those with sirolimus. More than half of the patients treated with everolimus had ≥ 50% reduction, and approximately 80% of them had ≥ 30% reduction, which was higher than that in patients treated with sirolimus. Regarding safety, there was no significant difference in the incidence of AEs between the two groups.

Conclusions

Both everolimus and sirolimus are excellent therapeutic options for TSC-AML. However, everolimus has a better therapeutic efficacy than sirolimus, particularly in reducing TSC-AML volume. Everolimus is therefore recommended as the first choice of therapy for TSC-AML.

Epidemiology, healthcare resource use, and mortality in patients with tuberous sclerosis complex: A population-based study on German health insurance data

PURPOSE

10-year retrospective study to assess burden of illness in individuals with tuberous sclerosis complex (TSC) identified from German healthcare data.

METHODS

Patients with TSC were identified by International Classification of Diseases code Q85.1. Patients with epilepsy were identified by epilepsy diagnosis or antiseizure medication (ASM) prescription after TSC diagnosis.

RESULTS

Using data from 2016 (final study year), 100 patients with TSC were identified (mean [range] age: 38 [1-86] years; male: 40%); prevalence: 7.9 per 100,000 (TSC), 2.2 per 100,000 (TSC with epilepsy). During the 10-year study period (2007-2016), 256 patients with TSC were identified and followed up for 1,784 patient-years (epilepsy: 36%, 616 patient-years). TSC manifestations/comorbidities (apart from epilepsy) were identified more frequently in patients with epilepsy than without. Mean annual healthcare costs for patients with TSC were €6,139 per patient-year (PPY), mostly attributable to medication (35%) and inpatient care (29%). Patients with epilepsy incurred costs more than double those without. Mean (standard deviation [SD]) annual hospitalisation rate (AHR) and length of stay (LOS) PPY: 0.5 (1.0) and 5.9 (18.6) days for TSC. AHR and LOS were greater in patients with epilepsy than without. Mean (SD) number of ASMs prescribed (TSC with epilepsy): 3.0 (2.3) over the entire observable time per patient. Mortality rates (vs. control): 5.08% (vs. 1.69%, p<0.001) for TSC, 7.53% (vs. 0.98%, p<0.001) for TSC with epilepsy, 3.68% (vs. 2.03%, p = 0.003) for TSC without epilepsy.

CONCLUSION

Healthcare costs, resource utilisation, and mortality were greater in patients with TSC and epilepsy than those without epilepsy.

Molecular Pathophysiology of Autosomal Recessive Polycystic Kidney Disease

Autosomal recessive polycystic kidney disease (ARPKD) is a rare disorder and one of the most severe forms of polycystic kidney disease, leading to end-stage renal disease (ESRD) in childhood. PKHD1 is the gene that is responsible for the vast majority of ARPKD. However, some cases have been related to a new gene that was recently identified (DZIP1L gene), as well as several ciliary genes that can mimic a ARPKD-like phenotypic spectrum. In addition, a number of molecular pathways involved in the ARPKD pathogenesis and progression were elucidated using cellular and animal models. However, the function of the ARPKD proteins and the molecular mechanism of the disease currently remain incompletely understood. Here, we review the clinics, treatment, genetics, and molecular basis of ARPKD, highlighting the most recent findings in the field.

Renal Neoplasia in Tuberous Sclerosis: A Study of 41 Patients

OBJECTIVE

To study the clinical features and identify unique renal neoplasia subtypes and their prognostic implications in individuals with tuberous sclerosis complex (TSC).

PATIENTS AND METHODS

The Mayo Clinic nephrectomy registry included 37 patients with TSC diagnosed between 1970 and 2018. Four additional patients were identified from the pathology consultation and autopsy files. All available renal tumors were further characterized using immunohistochemistry and fluorescence in situ hybridization. Clinicopathologic features and follow-up were obtained from the medical record. The American Association for Cancer Research Project GENIE registry was accessed using cBioPortal for molecular profiling of angiomyolipoma (AML).

RESULTS

A total of 276 renal tumors from 41 patients were analyzed. Renal tumors were classified into 9 distinct morphological subtypes, with AML predominating (238 [86%]). Interestingly, all these tumors acted in a benign fashion except one renal cell carcinoma with clear cells and fibromyomatous stroma and one epithelioid AML that metastasized. Molecular profiling studies revealed that epithelioid AMLs were enriched for alterations of TP53, RB1, and ATRX. Eight patients died of direct complications of TSC, including 3 of end-stage renal disease. To date, none have died of a renal epithelial neoplasm.

CONCLUSION

The identification of unique renal neoplasia subtypes may provide important clues to establish a diagnosis of TSC, and in the somatic setting, this finding has important implications for accurate prognostication. These tumors tend to be indolent, and only 2 of 276 tumors in our study exhibited metastatic behavior. Our results support multidisciplinary management with a focus on preservation of renal function.

TSC1 and TSC2: Tuberous Sclerosis Complex and Its Related Epilepsy Phenotype

Tuberous sclerosis complex (TSC) is an autosomal dominant disorder characterized by a multisystemic involvement. In TSC, reduced function of TSC1 and TSC2 genes products (hamartin and tuberin, respectively) leads to an hyperactivation of the mechanistic target of rapamycin (mTOR) pathway and to a consequent cell growth dysregulation. In TSC patients, neurological and neuropsychiatric manifestations, especially epilepsy and neuropsychiatric comorbidities such as autism or intellectual disability, represent the most disabling features. In particular, epilepsy occurrs up to 80% of patients, is often drug resistant and is frequently associated with neurological impairment. Due to the burden of this morbidity, different treatment strategies have been proposed with the purpose to make patients epilepsy free, such as the use of different antiepileptic drugs like vigabatrin, carbamazepine, valproic acid, and levetiracetam. More recently, a mTOR inhibitor (i.e. everolimus) has showed promising results in terms of seizures reduction.

Genomic and Pathological Characterization of Multiple Renal Cell Carcinoma Regions in Patient With Tuberous Sclerosis Complex: A Case Report

Tuberous sclerosis complex is a genetic disorder characterized by facial angiofibromas, intellectual disability, epilepsy, and tumor formation in multiple organs, including the kidney. Renal cell carcinoma occurs in 2%–4% of patients with tuberous sclerosis complex, often developing multiply and bilaterally. Renal cell carcinoma associated with this genetic disorder may include complex tumor heterogeneity caused by the spatially different mutational landscape. Herein, we report the case of a female patient with tuberous sclerosis complex who developed multiple renal tumors. A 44-year-old female patient with tuberous sclerosis complex developed three different histological types of tumor—angiomyolipoma, clear cell renal cell carcinoma, and papillary renal cell carcinoma—in the left kidney at first renal cell carcinoma recurrence. The papillary renal cell carcinoma was morphologically atypical, indicating that its occurrence was associated with the genetic disorder. Furthermore, whole-exome sequencing revealed distinct patterns of somatic mutation in the three tumor types, and the atypical papillary renal cell carcinoma possessed a different mutational landscape than that of typical papillary renal cell carcinomas. Our findings indicate that tumors associated with tuberous sclerosis complex may be diagnosed with careful pathological examination. Furthermore, somatic mutation profiles of these tumors revealed their unique features, providing important information for further understanding the mechanism of multiple tumor development in patients with tuberous sclerosis complex.

Congenital subpendymal giant cell astrocytoma in children with tuberous sclerosis complex: growth patterns and neurological outcome

BACKGROUND

Literature regarding congenital subependymal giant cell astrocytomas (SEGA) is limited, and suggests they are at risk of rapid growth and complications. We sought to characterise the growth patterns of congenital SEGA. The second part of the study was an exploratory analysis of congenital SEGA as a possible biomarker for poor neurological outcome.

METHODS

This single-centre case series describes ten patients with TSC who had SEGA diagnosed before 12 months. SEGA diameter and volumetric growth were analysed using serial MRIs. Neurological outcomes were compared to a genotype-matched group.

RESULTS

All children with congenital SEGA had a TSC2 mutation. Patients were followed for 1-8.7 years, during which median SEGA growth rate was 1.1 mm/yr in diameter or 150 mm³/yr volumetrically. SEGA with volume > 500 mm³ had a significantly higher growth rate compared with smaller SEGA (462 mm³/yr vs. 42 mm³/yr, p = 0.0095). Children with congenital SEGA had a high prevalence of severe epilepsy, developmental disability and autism spectrum disorder.

CONCLUSION

Congenital SEGA can follow a relatively benign course with a lower growth rate compared with published literature. Frequent neuroimaging surveillance is recommended for congenital SEGA with volumes exceeding 500 mm³.

IMPACT

Congenital SEGA occur in 9.2% of paediatric patients with tuberous sclerosis complex. There are few published cases of congenital SEGA to date. This case series of ten patients adds our experience seen in a tertiary referral hospital over 10 years. Congenital SEGA can follow a relatively benign course with a lower growth rate compared with published literature. Congenital SEGA with volume exceeding 500 mm³ had a significantly higher growth rate compared with smaller SEGA and should have more frequent neuroimaging surveillance.

The effect of sirolimus on angiomyolipoma is determined by decrease of fat-poor compartments and includes striking reduction of vascular structures

Renal angiomyolipomas hemorrhage is associated with their size and vascular constitution. The effects of sirolimus on different components of angiomyolipomas was analyzed in patients with tuberous sclerosis complex, sporadic lymphangioleiomyomatosis and multiple sporadic angiomyolipomas. Thirty angiomyolipomas from 14 patients treated with sirolimus were retrospectively evaluated. A Hounsfield-unit threshold was used to classify angiomyolipomas in fat-rich, fat-poor and intermediate-fat tumors, and to categorize tumor compartments in fat rich, fat poor, intermediate fat and highly vascularized. Diameter variations were measured to assess the effects on aneurysmatic/ectatic vascular formations. Volume reduction following treatment with sirolimus was higher in fat-poor than fat-rich angiomyolipomas. Tumor reduction was mainly determined by decrease of the fat-poor and highly-vascularized compartments while the volume of the fat-rich compartment increased. Broad liposubstitution was observed in some tumors. A median reduction of 100% (75 to 100) in the diameter of aneurysmatic/ectatic vascular structures was observed. Our study showed that sirolimus reduces the size of angiomyolipomas by decreasing primarily their highly-vascularized and fat-poor compartments. This effect is associated with a remarkable reduction of tumoral aneurysms/ectatic vessels, revealing the likely mechanism responsible for the risk-decreasing effect of mTOR inhibitors on angiomyolipoma bleeding. These findings support the role of mTOR in the development of angiomyolipoma blood vessels.

[Tuberous sclerosis system: A review]

Tuberous sclerosis complex (TSC) is an autosomal dominant disorder that affects different organs and caused by loss-of-function mutations in one of two genes: TSC1 or TSC2. TSC1 or TSC2 gene mutation lead to dysfunction of hamartin or tuberin, respectively. Hamartin and tuberin form a protein complex that helps regulate cellular proliferation. These proteins form a complex that constitutively inhibits the mammalian target of rapamycin (mTOR) signaling pathway, leading to permanent activation of mTOR signaling within all TSC-associated lesions. Major features of TSC include tumors of the brain, skin, heart, lungs and kidneys, seizures and TSC-associated neuropsychiatric disorders, which can include autism spectrum disorder and cognitive disability. These disorders are usually diagnosed in children and adults. Specific guidelines for diagnosis, surveillance, and management have been proposed by the International Tuberous Sclerosis Complex Consensus Group. Several randomized controlled trials led to regulatory approval of the use of mTOR inhibitors for the treatment of renal angiomyolipomas, brain subependymal giant cell astrocytomas, refractory epilepsy and pulmonary lymphangioleiomyomatosis.

Kidney Imaging Surveillance in Commercially Insured Patients With Tuberous Sclerosis Complex

BACKGROUND

Kidney disease has historically been the primary source of early mortality in adults with tuberous sclerosis complex (TSC). Kidney imaging surveillance promotes early detection of lesions requiring intervention. We describe kidney imaging frequency in relationship to patient-level characteristics for commercially insured patients with TSC in the United States.

METHODS

This retrospective observational study used 2003 to 2016 enrollment and claims data from a de-identified fully insured commercial health insurer. Patients with TSC less than 65 years were included. The patient-level kidney imaging rate was calculated as the number of kidney imaging procedures divided by length of continuous enrollment. A multiple linear regression model was used to determine the relationship between imaging rate and progression of TSC-associated kidney disease, number of specialists seen, and nephrologist care.

RESULTS

At least half of the 70 patients with TSC included in the study were aged 16 years or younger. Over a follow-up period of up to 14 years, the median kidney imaging rate was 0.13 procedures per year with 43% (N = 30) of patients lacking evidence of kidney imaging during the observation period. Imaging frequency increased with progression of TSC-associated kidney disease, more specialists, and nephrologist care (P < 0.05 for all three in regression model).

CONCLUSIONS

A substantial percentage of patients with TSC in the United States are at risk for delayed detection of kidney manifestations due to infrequent kidney imaging surveillance. Multispecialty care, including neurologists, may positively affect kidney surveillance rates.

Evaluation of cardiac arrhythmias by electrocardiographic markers in pediatric patients who have tuberous sclerosis without cardiac rhabdomyoma

BACKGROUND

Tuberous sclerosis (TS) is an autosomal dominant and hereditary disorder. Cardiac rhabdomyoma and arrhythmias are the most deleterious risk factors linked to TS. Although arrhythmias in pediatric patients with TS who have cardiac rhabdomyoma have been frequently reported, arrhythmia in patients who have TS without rhabdomyoma is rarely reported in the literature. The study aimed to assess the susceptibility of pediatric patients who have TS without cardiac rhabdomyoma to cardiac arrhythmia using electrocardiographic (ECG) markers.

METHODS

This prospective study included 10 patients who had TS without cardiac rhabdomyoma. The control group was made up of 30 healthy children of the same age and sex as the patient group. P wave, P wave dispersion, QT dispersion, QTc dispersion, TP-e interval, and TP-e interval dispersion were calculated on 12-lead surface ECGs for each patient in both groups and compared.

RESULTS

P wave, P wave dispersion, QT dispersion, and QTc dispersion were found to be significantly higher in the patient group (P<0.001). Furthermore, patients had a greater Tp-e interval and Tp-e interval dispersion than healthy children (P<0.001).

CONCLUSION

Pediatric patients with TS without cardiac rhabdomyoma might be prone to atrial and ventricular arrhythmias according to their prolonged ECG markers. Our findings suggest that patients with TS without cardiac rhabdomyoma need close monitoring for atrial and ventricular arrhythmias.

Acute encephalopathy in children with tuberous sclerosis complex

Objective

We examined the clinical manifestations of acute encephalopathy (AE) and identify risk factors for AE in children with tuberous sclerosis complex (TSC).

Methods

The clinical data of 11 children with clinically diagnosed TSC associated with AE and 109 children with clinically diagnosed TSC alone aged 4 years or older were collected from 13 hospitals.

Results

Of the 11 children with AE, 5 had histories of febrile seizures (FS), and all had histories of febrile status epilepticus (FSE). AE developed within 24 h after fever onset in all children with seizures lasting 30 min or longer. All children developed coma after seizure cessation. Head magnetic resonance imaging (MRI) revealed widespread abnormalities in the cerebral cortex, subcortical white matter, corpus callosum, basal ganglia, and thalamus. One child died; seven had severe neurological sequelae; and the other three, mild sequelae. Logistic regression analysis revealed that a history of FSE was correlated with the development of AE.

Significance

AE in children with TSC was characterized by sudden onset after fever, followed by coma, widespread brain edema evident on MRI, and poor outcomes. A history of FSE was a risk factor for the development of AE.

Abdominal ultrasonographic manifestations in pediatric patients with tuberous sclerosis complex

BACKGROUND

Tuberous sclerosis complex (TSC) is a rare genetic disease which leads to formation of benign tumors in the brain and other organs of the body. Ultrasound (US) can detect the location, quantity, size and internal echo of TSC-associated renal diseases, liver angiomyolipoma (AML), and co-existing lesions, providing important diagnostic basis for clinical diagnosis. The aim of the present study was to investigate the abdominal ultrasonographic features of pediatric TSC and explore the advantages of abdominal ultrasonography in clinical practice.

METHODS

Data of children with TSC, who presented to the Second Affiliated Hospital and Yuying Children's Hospital, Wenzhou Medical University, between January 2016 and November 2018, were analyzed by a retrospective chart review. The cases were identified from electronic medical records (EMR) system and underwent ultrasonography, we yielded a total of 12 patients.

RESULTS

The 12 pediatric patients, including 5 boys and 7 girls, ranged in age from 9 months to 13 years old. And they all had a history of epilepsy. All the patients underwent brain magnetic resonance imaging (MRI) or computed tomography (CT) examination, which revealed a scattered distribution of multiple hyperintense nodules. Of the 12 patients, 10 had TSC-associated bilateral renal AMLs, 5 had hepatic AML, and 4 had renal cysts.

CONCLUSIONS

US is a useful and non-invasive tool for the detection of TSC-associated renal and liver lesions and for clinical follow-up among pediatric patients.