17 research outputs found

    At-Risk Phenotype of Neurofibromatose-1 Patients: A Multicentre Case-Control Study

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    <p>Abstract</p> <p>Objectives</p> <p>To assess associations between subcutaneous neurofibromas (SC-NFs) and internal neurofibromas in patients with neurofibromatosis type 1 (NF-1) and to determine whether the association between SC-NFs and peripheral neuropathy was ascribable to internal neurofibromas.</p> <p>Patients and methods</p> <p>Prospective multicentre case-control study. Between 2005 and 2008, 110 NF-1 adults having two or more SC-NFs were individually matched for age, sex and hospital with 110 controls who had no SC-NF. Patients underwent standardized MRI of the spinal cord, nerve roots and sciatic nerves and an electrophysiological study. Analyses used adjusted multinomial logistic regression (ORa) to estimate the risk of the presence of internal neurofibromas or peripheral neuropathies associated with patients presented 2 to 9 SC-NFs, at least 10 SC-NFs as compared to patients without any (referential category).</p> <p>Results</p> <p>Cases had a mean age of 41 (± 13) years; 85 (80%) had two to nine SC-NFs and 21 (19%) at least ten SC-NFs. SC-NFs were more strongly associated with internal neurofibromas in patients with ten or more SC-NFs than in patients with fewer NF-SCs (e.g., sciatic nerve, aOR = 29.1 [8.5 to 100] vs. 4.3 [2.1 to 9.0]). The association with SC-NFs was stronger for diffuse, intradural, and > 3 cm internal neurofibromas than with other internal neurofibromas. Axonal neuropathy with slowed conduction velocities (SCV) was more strongly associated with having at least ten SC-NFs (aOR = 29.9, 5.5 to 162.3) than with having fewer SC-NFs (aOR = 4.4, 0.9 to 22.0). Bivariate analyses showed that the association between axonal neuropathy with SCV and sciatic neurofibromas was mediated by the association between SC-NFs and sciatic neurofibromas.</p> <p>Conclusion</p> <p>The at-risk phenotype of NF-1 patients (i.e. NF-1 patients with SC-NFs) is ascribable to associations linking SC-NFs to internal neurofibromas at risk for malignant transformation and to axonal neuropathies with slowed conduction velocities. Axonal neuropathies with SCV are particularly common in patients with at least ten SC-NFs.</p> <p>Registration details</p> <p>ORPHA86301</p

    Analytical quantification of the inflammatory cell infiltrate and CD95R expression during treatment of drug-induced toxic epidermal necrolysis.

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    The treatment of drug-induced toxic epidermal necrolysis (TEN) remains unsatisfactory. Intravenous immunoglobulins (IVIg) and intravenous cyclosporin A (CsA) have shown some efficacy in short series of patients. We assessed the effects of IVIg and CsA on TEN lesional and apparently uninvolved skin using standard histology and immunohistochemistry. Cutaneous biopsies were taken from necrotic and clinically uninvolved TEN skin at admission (D1) before any treatment, and after a 5-day treatment (D5). Two IVIg-treated patients (0.75 g/kg/day), two CsA-treated patients (5 mg/kg/day) and two control patients only receiving supportive care were compared. Biopsies were examined by standard histology and immunohistochemistry using antibodies directed to CD68 antigen (macrophages), CD45R0 antigen (activated T lymphocytes), Factor XIIIa (dermal dendrocytes) and the CD95 receptor (apoptosis marker). The different cell densities were evaluated by computerized image analysis. The clinical outcomes with the different treatments were also recorded. There was no obvious difference in the duration of hospitalization in intensive care unit between the three groups but one patient passed away in each of the IVIg- and CsA-groups. At D5, no differences were found between the three groups in the histological and clinical rate of re-epithelialization, and in the evolution of T lymphocyte, macrophage and dendrocyte densities in the epidermis and dermis. However, the expression of the CD95 receptor was similarly and strongly abated at D5 in the epidermis of IVIg- and CsA-treated patients, while it was conversely increased in the two patients under supportive care only. Such a difference was found both in necrotic and uninvolved sites. IVIg and CsA treatments thus appeared to exert no obvious effect on the inflammatory infiltrate, but both abated the expression of the CD95 receptor in the skin of TEN patients. This effect did not seem sufficient to fully reverse the clinical evolution of the disease. It is inferred that IVIg and CsA do not completely abate the TEN process

    Different Patterns of Mast Cells Distinguish Diffuse from Encapsulated Neurofibromas in Patients with Neurofibromatosis 1

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    Multiple neurofibromas are cardinal features of neurofibromatosis 1 (NF1). Several different types of NF1-associated neurofibromas occur, each distinct in terms of pathological details, clinical presentation, and natural history. Mast cells are present in most neurofibromas and have been shown to be critical to the origin and progression of neurofibromas in both human NF1 and relevant mouse models. In this investigation, the authors determined whether mast cell involvement is the same for all types of NF1-associated neurofibromas. They examined the density and distribution of mast cells within 49 NF1-associated neurofibromas classified histopathologically as diffuse or encapsulated on the basis of the presence or absence of the perineurium or its constituent cells. They made two observations: (1) Diffuse neurofibromas had significantly higher densities of mast cells than did encapsulated neurofibromas, and (2) mast cells were evenly distributed throughout diffuse neurofibromas but were primarily restricted to the periphery of encapsulated neurofibromas. The differences in mast cell density and distribution differentiate the two basic types of NF1-associated neurofibromas, suggesting that the pathogenesis of diffuse and encapsulated neurofibromas may be significantly different

    First International Conference on RASopathies and Neurofibromatoses in Asia: Identification and advances of new therapeutics

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    The neurofibromatoses, which include neurofibromatosis type I (NF1), neurofibromatosis type II (NF2), and schwannomatosis, are a group of syndromes characterized by tumor growth in the nervous system. The RASopathies are a group of syndromes caused by germline mutations in genes that encode components of the RAS/mitogen-activated protein kinase (MAPK) pathway. The RASopathies include NF1, Noonan syndrome, Noonan syndrome with multiple lentigines, Costello syndrome, cardio-facio-cutaneous syndrome, Legius syndrome, capillary malformation arterio-venous malformation syndrome, and SYNGAP1 autism. Due to their common underlying pathogenetic etiology, all these syndromes have significant phenotypic overlap of which one common feature include a predisposition to tumors, which may be benign or malignant. Together as a group, they represent one of the most common multiple congenital anomaly syndromes estimating to affect approximately one in 1000 individuals worldwide. The subcontinent of India represents one of the largest populations in the world, yet remains underserved from an aspect of clinical genetics services. In an effort to bridge this gap, the First International Conference on RASopathies and Neurofibromatoses in Asia: Identification and Advances of New Therapeutics was held in Kochi, Kerala, India. These proceedings chronicle this timely and topical international symposium directed at discussing the best practices and therapies for individuals with neurofibromatoses and RASopathies.status: publishe

    First International Conference on RASopathies and Neurofibromatoses in Asia: Identification and advances of new therapeutics

    No full text
    The neurofibromatoses, which include neurofibromatosis type I (NF1), neurofibromatosis type II (NF2), and schwannomatosis, are a group of syndromes characterized by tumor growth in the nervous system. The RASopathies are a group of syndromes caused by germline mutations in genes that encode components of the RAS/mitogen-activated protein kinase (MAPK) pathway. The RASopathies include NF1, Noonan syndrome, Noonan syndrome with multiple lentigines, Costello syndrome, cardio-facio-cutaneous syndrome, Legius syndrome, capillary malformation arterio-venous malformation syndrome and SYNGAP1 autism. Due to their common underlying pathogenetic etiology, all these syndromes have significant phenotypic overlap of which one common feature include a predisposition to tumors, which may be benign or malignant. Together as a group, they represent one of the most common multiple congenital anomaly syndromes estimating to affect approximately one in 1000 individuals worldwide. The subcontinent of India represents one of the largest populations in the world, yet remains underserved from an aspect of clinical genetics services. In an effort to bridge this gap, the First International Conference on RASopathies and Neurofibromatoses in Asia: Identification and Advances of New Therapeutics was held in Kochi, Kerala, India. These proceedings chronicle this timely and topical international symposium directed at discussing the best practices and therapies for individuals with neurofibromatoses and RASopathies
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