Validation of the Index for Facial Angiofibromas: Data analysis from a randomized controlled trial of sirolimus gel treatment in patients with tuberous sclerosis complex.

The Index for Facial Angiofibromas (IFA), a novel scoring system for angiofibromas, has been validated in patients with tuberous sclerosis complex (TSC). The objective of this analysis was to further validate the IFA using data from a clinical trial of topical sirolimus in patients with TSC. This was an analysis of photographs from a Phase III trial conducted in Japan (NCT02635789). Patients (n = 62) were randomized 1:1 to receive sirolimus or placebo gel for 12 weeks. Changes in angiofibromas were independently assessed using the primary composite endpoint, the Facial Angiofibroma Severity Index (FASI), and the IFA. Thresholds for a clinically meaningful change in IFA score were evaluated using receiver operating characteristic (ROC) analysis. The IFA scores had good-to-excellent inter-assessor reliability, very high intra-assessor reliability, and could be used to evaluate the distribution of disease severity at baseline. High correlations were observed between the categorized change from baseline in IFA scores and the primary composite endpoint (Kendall's coefficient of concordance, W = 0.8655, p < 0.0001), and between the change from baseline in IFA and FASI scores (Kendall's coefficient of concordance, W = 0.745, p < 0.0001). By ROC analysis, an optimal IFA cut-off point of 1.667 was determined to distinguish patients with markedly improved or improved angiofibromas from those with slightly improved or unchanged angiofibromas (area under the curve 0.937) as determined by the primary composite endpoint. The IFA score is potentially clinically useful because of its high validity and reliability. A decrease in score from baseline of ≥1.667 may be considered clinically meaningful.

Distinct Transcriptional Profiles in the Different Phenotypes of Neurofibroma from the Same Subject with Neurofibromatosis 1.

Neurofibromatosis 1 is a prevalent hereditary neurocutaneous disorder. Among the clinical phenotypes of neurofibromatosis 1, cutaneous neurofibroma (cNF) and plexiform neurofibroma (pNF) have distinct clinical manifestations, and pNF should be closely monitored owing to its malignant potential. However, the detailed distinct features of neurofibromatosis 1 phenotypes remain unknown. To determine whether the transcriptional features and microenvironment of cNF and pNF differ, single-cell RNA sequencing was performed on isolated cNF and pNF cells from the same patient. Six cNF and five pNF specimens from different subjects were also immunohistochemically analyzed. Our findings revealed that cNF and pNF had distinct transcriptional profiles even within the same subject. pNF is enriched in Schwann cells with characteristics similar to those of their malignant counterpart, fibroblasts, with a cancer-associated fibroblast-like phenotype, angiogenic endothelial cells, and M2-like macrophages, whereas cNF is enriched in CD8 T cells with tissue residency markers. The results of immunohistochemical analyses performed on different subjects agreed with those of single-cell RNA sequencing. This study found that cNF and pNF, the different neurofibromatosis phenotypes in neurofibromatosis 1, from the same subject are transcriptionally distinct in terms of the cell types involved, including T cells.

Tuberous Sclerosis Complex.

Tuberous sclerosis complex (TSC) is an autosomal dominant inherited disease characterized by systemic hamartomas, neuropsychiatric symptoms known as TAND (TSC-associated neuropsychiatric disorders), and vitiligo. These symptoms are attributed to the constant activation of mechanistic target of rapamycin complex 1 (mTORC1) caused by genetic mutations in the causative genes TSC1 or TSC2. The elucidation of the pathogenesis of this disease and advances in diagnostic technologies have led to dramatic changes in the diagnosis and treatment of TSC. Diagnostic criteria have been created at a global level, and mTORC1 inhibitors have emerged as therapeutic agents for this disease. Previously, the treatment strategy was limited to symptomatic treatments such as surgery. Inhibitors of mTORC1 are effective against all symptoms of TSC, but they also have systemic side effects. Therefore, the need for a cross-disciplinary, collaborative medical care system has increased, resulting in the establishment of a practice structure known as the "TSC Board." Furthermore, to reduce the side effects of systemic administration of mTORC1 inhibitors, a topical formulation of mTORC1 inhibitor was developed in Japan for the treatment of skin lesions caused by TSC. This report summarizes the pathogenesis and current status of TSC and the contribution of the Neurocutaneous Syndrome Policy Research Group to the policies of the Ministry of Health, Labor, and Welfare with respect to this rare, intractable disease.

Verification of the efficacy of topical sirolimus gel for systemic rare vascular malformations: a pilot study.

Numerous clinical trials of sirolimus, an inhibitor of mechanistic/mammalian target of rapamycin complex 1, for the treatment of vascular malformations have been conducted. However, aside from lymphatic malformations, the efficacy of sirolimus for venous and capillary malformations has not been established. Moreover, no generalized venous or capillary malformations have been treated with topical sirolimus. To evaluate the safety and efficacy of topical sirolimus for venous and capillary malformations and to compare the efficacy of topical and systemic sirolimus therapy, an open-label single-arm pilot study with 0.2% sirolimus gel was conducted from July 19, 2019, to January 30, 2020, in four patients diagnosed with different vascular malformations (blue rubber bleb nevus syndrome, common venous malformation, phakomatosis pigmentovascularis type IVb, and angiokeratoma in Fabry disease). The primary endpoint was the safety evaluation of sirolimus gel. The main secondary endpoint was the improvement rate evaluated by the Central Judgment Committee at 12 weeks using photographs. No adverse events were observed. Blood sirolimus was not detected in any patient. Two patients (50%) had mild improvement, and the remaining two patients (50%) showed no change after 12 weeks of treatment. Blue rubber bleb nevus syndrome, a generalized venous malformation, showed the greatest response. In conclusion, 0.2% sirolimus gel was found to be as clinically effective as systemic sirolimus treatment in patients with venous and capillary malformations and more effective for early active lesions, even systemic venous malformations.

Sirolimus relieves seizures and neuropsychiatric symptoms via changes of microglial polarity in tuberous sclerosis complex model mice.

Tuberous sclerosis complex (TSC) is a genetic disorder involving a variety of physical manifestations, and is associated with epilepsy and multiple serious neuropsychiatric symptoms. These symptoms are collectively known as TSC-associated neuropsychiatric disorders (TAND), which is a severe burden for patients and their families. Overactivation of the mechanistic target of rapamycin complex 1 (mTORC1) by mutations in TSC1 or TSC2 is thought to cause TSC, and mTORC1 inhibitors such as sirolimus and everolimus are reported to be effective against various tumor types of TSC. However, there are various reports on the effect of mTORC1 inhibitor therapy on TAND in patients with TSC, which may or may not be effective. In our previous investigations, we generated TSC2 conditional knockout mice (Mitf-Cre, Tsc2 KO; Tsc2 cKO). These mice developed spontaneous epileptic activity. In the current study, we further analyzed the detailed behaviors of Tsc2 cKO mice and confirmed that they exhibited phenotypes of TAND as well as epileptic seizures, indicating that Tsc2 cKO mice are a useful model for TAND. Furthermore, the olfactory bulb and piriform cortex caused epilepsy and TAND in Tsc2 cKO mice, and neurodegeneration was observed. Immunohistology and immunophenotypic analysis of cells, and quantitative RT-PCR suggested that changes in microglial polarity were involved in the onset of TSC epilepsy and neuropsychiatric symptoms. Although the effect of mTORC1 inhibitors on TAND has not been established, the results of this study might help elucidate the mechanism of TAND pathogenesis and suggest that sirolimus may be a valuable therapeutic tool for TAND.

Abnormal White Matter Microstructure in the Limbic System Is Associated With Tuberous Sclerosis Complex-Associated Neuropsychiatric Disorders.

Objective: Tuberous sclerosis complex (TSC) is a genetic disease that arises from TSC1 or TSC2 abnormalities and induces the overactivation of the mammalian/mechanistic target of rapamycin pathways. The neurological symptoms of TSC include epilepsy and tuberous sclerosis complex-associated neuropsychiatric disorders (TAND). Although TAND affects TSC patients' quality of life, the specific region in the brain associated with TAND remains unknown. We examined the association between white matter microstructural abnormalities and TAND, using diffusion tensor imaging (DTI). Methods: A total of 19 subjects with TSC and 24 age-matched control subjects were enrolled. Tract-based spatial statistics (TBSS) were performed to assess group differences in fractional anisotropy (FA) between the TSC and control groups. Atlas-based association analysis was performed to reveal TAND-related white matter in subjects with TSC. Multiple linear regression was performed to evaluate the association between TAND and the DTI parameters; FA and mean diffusivity in seven target regions and projection fibers. Results: The TBSS showed significantly reduced FA in the right hemisphere and particularly in the inferior frontal occipital fasciculus (IFOF), inferior longitudinal fasciculus (ILF), superior longitudinal fasciculus (SLF), uncinate fasciculus (UF), and genu of corpus callosum (CC) in the TSC group relative to the control group. In the association analysis, intellectual disability was widely associated with all target regions. In contrast, behavioral problems and autistic features were associated with the limbic system white matter and anterior limb of the internal capsule (ALIC) and CC. Conclusion: The disruption of white matter integrity may induce underconnectivity between cortical and subcortical regions. These findings suggest that TANDs are not the result of an abnormality in a specific brain region, but rather caused by connectivity dysfunction as a network disorder. This study indicates that abnormal white matter connectivity including the limbic system is relevant to TAND. The analysis of brain and behavior relationship is a feasible approach to reveal TAND related white matter and neural networks. TAND should be carefully assessed and treated at an early stage.

Clinical practice guidelines for pseudoxanthoma elasticum (2017): Clinical Practice Guidelines for Pseudoxanthoma Elasticum Drafting Committee

Pseudoxanthoma elasticum (PXE) is a progressive hereditary disease that affects tissues such as the skin, retina, blood vessels, and gastrointestinal tracts. Therefore, comprehensive medical care across clinical departments specialized in specific organs is needed to provide the best clinical practices to PXE patients. The Japanese version of clinical guidelines developed by the Japanese Dermatological Association was published in 2017, and aimed to promote equal accessibility of PXE-related medical care. Here, the English version of Japanese guideline is reported, and is intended to be worldwide reference for medical care of PXE.

Safety and Efficacy of the Sirolimus Gel for TSC Patients With Facial Skin Lesions in a Long-Term, Open-Label, Extension, Uncontrolled Clinical Trial.

INTRODUCTION: Our previous clinical studies have demonstrated the short-term efficacy and safety of the sirolimus gel for patients with tuberous sclerosis complex (TSC). However, long-term clinical evidence is lacking. Our objective was to assess the safety and efficacy of long-term treatment with the sirolimus gel for the skin lesions of TSC patients. METHODS: We conducted a multicenter, open-label, uncontrolled clinical trial in 94 Japanese patients with TSC. Patients applied the 0.2% sirolimus gel on their face or head twice daily for > 52 weeks (maximum 136 weeks for safety). The safety endpoints were the rate of adverse event (AE)-caused discontinuation (primary endpoint) and the incidence of AEs. The efficacy endpoint was the response rate of angiofibromas, cephalic plaques, and hypomelanotic macules. RESULTS: Among 94 enrolled patients (mean age, 21 years; range 3-53 years), the rate of AE-caused discontinuation was 2.1% (2/94 patients). Although application site irritation and dry skin occurred relatively frequently, none of the drug-related AEs were serious; most of the drug-related AEs resolved rapidly. The major drug-related AEs (≥ 5% in incidence) were application site irritation (30.9%), dry skin (27.7%), acne (20.2%), eye irritation (8.5%), pruritus (8.5%), erythema (7.4%), dermatitis acneiform (6.4%), and dermatitis contact (5.3%). The response rates of angiofibromas, cephalic plaques, and hypomelanotic macules were 78.2% [95% confidence interval (CI) 68.0-86.3%], 66.7% (95% CI 51.1-80.0%), and 72.2% (95% CI 46.5-90.3%), respectively. CONCLUSIONS: The gel was well tolerated for a long time by patients with TSC involving facial skin lesions and continued to be effective. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT02634931.