Assessment of Tuberous Sclerosis Complex Associated With Renal Lesions by Targeted Next-generation Sequencing in Mainland China

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.

The association between computed tomography attenuation value of renal angiomyolipoma associated with tuberous sclerosis complex and response to everolimus

BACKGROUND

The response to everolimus in patients with renal angiomyolipoma associated with tuberous sclerosis complex (TSC-RAML) varies among individuals. This study aims to identify potential factors associated with the response to everolimus.

METHOD

We retrospectively examined data encompassing age, gender, tumor size, computed tomography attenuation value (CT value), CT enhancement, and tumor reduction rate in patients with TSC-RAML undergoing everolimus in two previously registered clinical trials.

RESULT

A total of 33 participants (29.33 ± 6.63 years old, 20 females) were included. The correlation analysis conducted separately for tumors located in the left and right kidneys revealed significant negative correlations (P < 0.05) between tumor reduction rate and age, as well as tumor size. While significant positive correlations (P < 0.05) were observed between tumor reduction rate and unenhanced CT value as well as CT enhancement. Nonetheless, based on multiple linear regression analysis, unenhanced CT value emerged as the sole-independent predictor of tumor reduction rate among age, gender, tumor size, unenhanced CT value and CT enhancement for both left (coefficient = 0.00319, P < 0.0001) and right kidneys (coefficient = 0.00315, P = 0.0104). Notable reductions were observed in unenhanced CT value (- 3.81 vs - 24.70HU, P < 0.0001) and CT enhancement (48.16 vs 33.56HU, P < 0.0001) following a 3-month administration of everolimus. The decline in both unenhanced CT value and tumor size predominantly occurred within the initial 3 months, subsequently maintaining a relatively stable level throughout the treatment.

CONCLUSION

The unenhanced CT value of TSC-RAML showed an independent correlation with the response to everolimus, suggesting its potential as a predictor of everolimus efficacy in patients with TSC-RAML.

The Importance of Genetic Testing in the Differential Diagnosis of Atypical TSC2-PKD1 Contiguous Gene Syndrome-Case Series

BACKGROUND

In clinical practice, the possible diagnosis of tuberous sclerosis or polycystic kidney disease is primarily based on clinical criteria, which can later be verified by genetic testing. But in the case of TSC2/PKD1 contiguous gene syndrome (TSC2/PKD1-CGS), the renal appearance of the disease is more serious. Therefore, early genetic analysis is recommended.

METHODS

Herein we present the report of four children with TSC2/PKD1-CGS, one involving the NTHL1 gene. We aim to emphasize the importance of genetic testing in this rare syndrome.

RESULTS

During the follow-up of tuberous sclerosis and polycystic kidney disease patients, it is essential to reappraise the diagnosis if the clinical symptoms' appearance or onset time is unusual. Targeted genetic testing is recommended. However, early tumor formation necessitates the extension of genetic analysis.

CONCLUSIONS

An appropriate evaluation of the phenotype is the cornerstone of diagnosing the rare TSC2/PKD1-CGS with the help of genetic results. In addition, malignant tumors could draw attention to an infrequent large deletion.

Safety and Effectiveness of Medical Therapy and Surgical Intervention for Renal Angiomyolipoma Associated With Tuberous Sclerosis Complex

PURPOSE

Our study aimed to evaluate the effect of daily oral dose of everolimus in the treatment of patients with tuberous sclerosis complex (TSC) associated with renal angiomyolipoma (RAML), and the feasibility and safety of surgical treatment approach.

METHODS

We retrospectively investigated a total of 13 patients diagnosed of TSC-associated renal angiomyolipoma (TSC-RAML) who were scheduled for everolimus therapy. At 3-9 months after starting everolimus therapy, 4 of the study patients were symptomatic and underwent partial renal resection surgery. Two of these surgeries were performed open nephron sparing surgery (NSS) after TAE (Trans-arterial embolization), while the remaining 2 underwent robot-assisted partial nephrectomy (RAPN). A multi-slice helical CT scan performed among all the patients every 3 months, which was used to measure the volume and the density of the lesion.

RESULTS

Follow-up CT images revealed a significant reduction (P < .05) in the RAML volume, at a rate ranging from 11.6 to 42.5%, in response to everolimus therapy (10 mg/day) in TSC-RAML patients. Further, a significant decrease in the mean tumor density (P < .05), as compared to its baseline value, was also observed. Super-selective renal arterial embolization done prior to NSS was effective in reducing the intraoperative bleeding and stabilizing the patient during the NSS procedure: mean warm ischemia time was 29.5 minutes (range 18-40 minutes) and mean intraoperative bleeding volume was 275 mL (range 200-350 mL). Post-surgical (both NSS and RAPN) follow-up showed a favorable perioperative morbidity profile with good renal functional preservation. At the end of 2 years, all patients were well, with no signs of progression or recurrence of the condition, and demonstrated normal renal function.

CONCLUSIONS

The results suggested oral everolimus as an effective non-invasive therapy to treat TSC-RAML patients. Post mTOR inhibitor therapy, NSS and RAPN are preferred mode of surgical intervention in symptomatic patients. TAE prior to NSS is beneficial.

Analysis of Clinical Features and Next-Generation Sequencing of 12 Tuberous Sclerosis Families in China

Background

Tuberous sclerosis complex (TSC) is a rare autosomal dominant genetic disease with systemic organ involvement. So far, only a few TSC families in China have been reported. Therefore, more data on the clinical and genetic features of TSC families are required.

Materials and Methods

We retrospectively analyzed 12 TSC family probands and their family members. Next-generation sequencing (NGS) has been applied to confirm the type of TSC mutation along with a detailed physical examination.

Results

In this study, twenty-seven patients in 12 TSC families were reported, including 12 male and 15 female patients, aged 8-67 years. Skin lesions were detected among all patients with TSC, including 25 cases of facial angiofibromas, 18 cases of hypomelanotic macules, 15 cases of ungual fibromas, and 13 cases of shagreen patch. Other clinical features were also revealed: 14 cases of renal angiomyolipoma, 6 cases of subependymal nodules (SENs), and 3 cases of lymphangioleiomyomatosis. All twenty-seven patients with TSC were tested by NGS. Totally, TSC2 mutations were reported in 19 cases (7 frameshift mutations, 10 nonsense mutations, and 2 missense mutations), TSC1 mutations were reported in 4 cases (4 nonsense mutations), and 4 cases were genetically negative. The novel causal mutations (TSC2: c.208dup, c.1874C > G, c.1852del) identified in three families were first reported in TSC.

Conclusion

Our findings expand the mutation spectrum of patients with TSC in China. The clinical characteristics can vary among patients with TSC with the same pathogenic mutation. The genetic results and summary of clinical features of 12 TSC families contribute to a more accurate diagnosis and further genetic counseling.

Low-Dose Everolimus Maintenance Therapy for Renal Angiomyolipoma Associated With Tuberous Sclerosis Complex

Objective: To assess the safety and efficacy of low-dose everolimus maintenance therapy for tuberous sclerosis complex-related renal angiomyolipoma (TSC-RAML) patients that had previously undergone standard-dose treatment for a minimum of 6 months.

Materials and Methods: In total, 24 patients with a definitive TSC diagnosis were enrolled from April 2018 – April 2019 at Xiangya Hospital, Central South University. All patients underwent low-dose everolimus maintenance therapy following standard-dose everolimus induction therapy for a minimum of 6 months. Patients additionally underwent TSC1/TSC2 genetic testing, And they were followed-up at 3, 6, 12, 18, and 24 months. The Response Evaluation Criteria in Solid Tumors (RECIST, version 1.1) criteria were used to monitor patient RAML responses, while adverse events (AEs) were assessed as per the National Cancer Institute Common Terminology Criteria for Adverse Events (CTCAE, version 4.0). P < 0.05 was the significance level for all analyses, which were performed using SPSS 19.0.

Results: TSC1/TSC2 gene mutations were present in all 24 patients, all of whom achieved a significant reduction in TSC-RAML volume within the initial 6-month induction therapy period, and exhibited volume stabilization during the low-dose maintenance therapy treatment period without any instances of TSC-RAML regrowth. Adverse events (AEs) were significantly less severe and less frequent over the course of maintenance therapy relative to standard therapy.

Conclusions: Low-dose everolimus maintenance therapy represents an effective approach to achieving TSC-RAML control following a minimum of 6 months of full-dose induction therapy, and may be associated with decreases in everolimus-related AE frequency and severity.

High-throughput screening of circRNAs reveals novel mechanisms of tuberous sclerosis complex-related renal angiomyolipoma

Objective

Tuberous sclerosis complex (TSC) is a rare autosomal dominant disease characterized by lesions throughout the body. Our previous study showed the abnormal up-regulation of miRNAs plays an important part in the pathogenesis of TSC-related renal angiomyolipoma (TSC-RAML). circRNAs were known as important regulators of miRNA, but little is known about the circRNAs in TSC-RAMLs.

Methods

Microarray chips and RNA sequencing were used to identify the circRNAs and mRNAs that were differently expressed between the TSC-RAML and normal kidney tissue. A competitive endogenous RNA (ceRNA) regulatory network was constructed to reveal the regulation of miRNAs and mRNAs by the circRNAs. The biological functions of circRNA and mRNA were analyzed by pathway analysis. Microenvironmental cell types were estimated with the MCP-counter package.

Results

We identified 491 differentially expressed circRNAs (DECs) and 212 differentially expressed genes (DEGs), and 6 DECs were further confirmed by q-PCR. A ceRNA regulatory network which included 6 DECs, 5 miRNAs, and 63 mRNAs was established. Lipid biosynthetic process was significantly up-regulated in TSC-RAML, and the humoral immune response and the leukocyte chemotaxis pathway were found to be down-regulated. Fibroblasts are enriched in TSC-RAML, and the up-regulation of circRNA_000799 and circRNA_025332 may be significantly correlated to the infiltration of the fibroblasts.

Conclusion

circRNAs may regulate the lipid metabolism of TSC-RAML by regulation of the miRNAs. Fibroblasts are enriched in TSC-RAMLs, and the population of fibroblast may be related to the alteration of circRNAs of TSC-RAML. Lipid metabolism in fibroblasts is a potential treatment target for TSC-RAML.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40246-021-00344-1.

[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.

Mutational analysis of renal angiomyolipoma associated with tuberous sclerosis complex and the outcome of short-term everolimus therapy

To identify clinical characteristics and mutation spectra in Chinese patients with renal angiomyolipoma (AML) associated with the tuberous sclerosis complex (TSC, TSC-AML), examined the efficacy and safety of short-term everolimus therapy (12 weeks). We analyzed the frequency distribution of each TSC-related clinical feature and investigated gene mutations by genetic testing. Some subjects received everolimus for 12 weeks at a dose of 10 mg/day, and the efficacy and safety of short-term everolimus therapy were examined. Finally, 82 TSC-AML patients were enrolled for analysis in this study. Of the 47 patients who underwent genetic testing, 22 patients (46.81%) had at least one detectable mutation in the TSC1 or TSC2 gene: 7 were TSC1 gene mutations, 13 were TSC2 gene mutations, and 2 were found in both TSC1 and TSC2. Everolimus treatment had a statistically significant effect on the renal AML volume reduction during follow-up (P < 0.05), and the mean reduction rate of volume for all cases was 56.47 ± 23.32% over 12 weeks. However, 7 patients (7/25; 28.00%) experienced an increase in renal AML tumor volume within 12 weeks after discontinuation of the everolimus treatment. Although most patients (27/30, 90.00%) experienced some adverse events during the treatment period, all such events were mild, and no patients discontinued or needed dose reduction because of adverse events. Overall, in this study, the mutation rate of TSC-AML patients is much lower than other reports. Short-term everolimus treatment for TSC-AML is effective and safe, but the stability is much lower than long-term therapy.

CT characteristics predict the response to everolimus or sirolimus of renal angiomyolipomas in patients with tuberous sclerosis complex

OBJECTIVE

To investigate factors influencing the volume response of everolimus and sirolimus in tuberous sclerosis complex (TSC) associated-angiomyolipomas (AML).

METHODS

A retrospective analysis of 30 cases of TSC-AML treated by mTOR inhibitors (everolimus 18 cases, and sirolimus 12 cases) between April 2014 and November 2017 at our center was carried out. Epidemiological data, therapeutic response and influence factors were reviewed and analyzed. Age, sex, associated with SEGA and/or LAM or not, plasma rapamycin concentration, AML volume at baseline, and mean CT value of AML in the maximum cross-section at baseline were analyzed as potential influencing factors.

RESULTS

Eighteen patients with 32 lesions in everolimus group and 12 patients with 15 lesions in sirolimus group were included. There was no statistically significant difference of baseline characteristics except for involved side (P = 0.008) between two groups. The mean volume of AML was 1000 ± 1276 cm³ at baseline and 633 ± 1121 cm³ at 6 months after treatment (P < 0.001) in everolimus group, and 1984 ± 2861 cm³ at baseline and 1733 ± 2533 cm³ at 6 months after treatment (P = 0.001) in sirolimus group, respectively. The mean volume reduction of the AML in everolimus and sirolimus groups were 55.56% ± 23.79% and 30.5% ± 22.8% (P = 0.001). Stepwise multiple linear regression analysis revealed that factors influencing the short-term volume response of everolimus and sirolimus for TSC-associated AML were AML volume at baseline (P < 0.001 and 0.038, respectively) and mean CT value at baseline (P < 0.001 and 0.020, respectively). The rates of ≥ 50% volume reduction in high CT value group was much higher than that in low CT value group (90.5% vs. 18.2%, P < 0.001).

CONCLUSIONS

Everolimus at 10 mg daily might be more effective than sirolimus at 2 mg daily in treatment of patients with TSC-AML. AML volume and mean CT value at baseline were factors influencing the short-term volume response of everolimus or sirolimus for TSC-AML.

Assessing the outcomes of everolimus on renal angiomyolipoma associated with tuberous sclerosis complex in China: a two years trial

Background

Tuberous sclerosis complex (TSC) is a rare autosomal dominant genetic disorder characterized by the development of numerous benign tumors. Renal angiomyolipoma (RAML) occur in up to 80% of TSC patients, which is a leading cause of TSC-related death in adult patients. The aim of the study was to evaluate the efficacy and safety profiles of everolimus in Chinese patients of TSC associated with RAML(TSC-RAML).

Methods

In this 2-years, nonrandomized, open-label trial, 18 patients of TSC-RAML, with at least one RAML 3 cm or larger in its longest diameter, were enrolled to assess the efficacy and safety of everolimus therapy in Chinese patients. Everolimus was administered for the first 12 months only. The primary endpoint was a reduction of 50% or more relative in RAML volume to the baseline in the absence of new RAML ≥1 cm and no RAML-related bleeding of grade ≥ 2. The secondary endpoints included: safety, lung function and skin lesions response rate. Serial computed tomography of RAML, magnetic resonance imaging of brain lesions and pulmonary-function tests were performed. Adverse events were investigated using CTCAE v4.0. All analyses used a significance level of 0.05 and were generated in SPSS19.0 software.

Results

The proportion of patients who achieved ≥50% reduction from baseline in the sum of volumes of target lesions increased from 52.94% at 3 months, to 58.82% and 66.67% at months 6 and 12, respectively. During the period of everolimus therapy, among patients with lymphangioleiomyomatosis, the mean forced expiratory volume in 1 s (FEV1) increased by 276 ± 78 ml (P < 0.001), the forced vital capacity (FVC) increased by 433 ± 170 ml (P < 0.001), and the residual volume decreased by 408 ± 243 ml (P = 0.009), as compared with baseline values. The angiomyolipoma volume and the lung function approached, but did not completely return to, the baseline values. The skin lesions response rate was 37.5% after 12 months of therapy falling to 21.4% at 12 months after stopping everolimus. The most common adverse events were mucositis oral, irregular menstruation, abdominal pain, hypertriglyceridemia and headache. The most common grade 3 adverse events were irregular menstruation and mucositis oral. In addition, one patient died from RAML spontaneous haemorrhage during treatment with everolimus, even with reduction in RAML volume of 60.68% at 3 months. A second death was due to epithelioid RAML progression, with metastasis to multiple retroperitoneal lymph node, who died from severe infection one month after surgery.

Conclusions

Angiomyolipomas regressed somewhat during everolimus therapy but tended to increase in volume after the therapy was stopped. Everolimus was well tolerated and showed promising activity in Chinese patients with TSC-RAML, however, we should alert the life-threatening hemorrhage of large RAML in the early period and the lymph node metastasis of epithelioid RAML.

Trial registration

ChiCTR-OPC-14005488. Registered November 17, 2014.

Electronic supplementary material

The online version of this article (10.1186/s13023-018-0781-y) contains supplementary material, which is available to authorized users.