Publications by authors named "Nicolas Ortonne"

Article Synopsis
  • - The study investigates primary cutaneous marginal zone lymphoma (PCMZL) by analyzing recurrent cases to determine whether it's a reactive process or a true lymphoma, utilizing data from the French Study Group of Cutaneous Lymphoma (GFELC).
  • - Methods included assessing histology, B-cell clonality, and immunophenotype of lesions, revealing that most initial cases were localized, with differences in recurrence times based on location, and certain clonal patterns were more prominent in local recurrences.
  • - The findings suggest that assessing immunoglobulin phenotype, particularly IgM and IgD, may be critical for diagnosing PCMZL, as IgM-positive cases tend to lead to more aggressive transformation and poorer prognosis, indicating different biological
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  • * Some skin lesions can be subtle, often categorized as "invisible" dermatoses, like primary macular cutaneous amyloidosis and calciphylaxis, necessitating detailed examination.
  • * Certain conditions have significant prognostic implications, indicating potential underlying diseases like monoclonal gammopathies or association with visceral damage, underscoring the importance of clinical-pathological comparison to differentiate between serious conditions.
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Background: Mycosis fungoides (MF) has usually an indolent course. However, some patients develop a more aggressive disease and few prognostic parameters have been identified. Isolated cases of pustular MF (pMF) suggest an unfavourable prognosis.

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Malignant peripheral nerve sheath tumors (MPNSTs) are the leading cause of death in patients with neurofibromatosis type 1. They can result from premalignant neurofibromas, including neurofibromas with atypia and atypical neurofibromatous neoplasms of uncertain biologic potential. Some phenotypic characteristics have been described as associated with their development.

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The PDCD1-encoded immune checkpoint receptor PD-1 is a key tumor suppressor in T cells that is recurrently inactivated in T cell non-Hodgkin lymphomas (T-NHLs). The highest frequencies of PDCD1 deletions are detected in advanced disease, predicting inferior prognosis. However, the tumor-suppressive mechanisms of PD-1 signaling remain unknown.

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T-follicular helper (TFH) markers are expressed in the microenvironnement of marginal zone B-cell lymphoma (MZL), and in lymphomas arising from TFH-cells, sometimes making the differential diagnosis difficult. In the skin, the "TFH-spectrum" is poorly defined, going from primary cutaneous lymphoproliferative disorder with small/medium CD4+ T-cells (SMLPD) to cutaneous localizations of systemic angioimmunoblastic T-cell lymphoma (cAITL), and may pass through intermediate forms (primary cutaneous T-follicular helper derived lymphoma, not otherwise specified (PCTFHL,NOS)). We retrospectively analyzed 20 MZL, 13 SMLPD, 5 PCTFHL, and 11 cAITL clinically, histologically, and molecularly, to define tools to differentiate them.

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Background: Primary cutaneous peripheral T-cell lymphomas with a T-follicular helper phenotype (pcTFH-PTCL) are poorly characterized, and often compared to, but not corresponding with, mycosis fungoides (MF), Sézary syndrome, primary cutaneous CD4 lymphoproliferative disorder, and skin manifestations of angioimmunoblastic T-cell lymphomas (AITL).

Objectives: We describe the clinicopathological features of pcTFH-PTCL in this original series of 23 patients, and also characterize these cases molecularly.

Methods: Clinical and histopathological data of the selected patients were reviewed.

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Article Synopsis
  • A study was conducted on a family with a rare form of chronic urticarial lesions that are inherited dominantly and linked to elevated cytokine levels.
  • Researchers used genetic analysis, whole-exome sequencing, and proteomic methods to identify the underlying causes and associated proteins related to the condition.
  • The findings revealed a loss-of-function mutation in the RNF213 gene, affecting a protein called mysterin, which plays a significant role in regulating inflammation and understanding immune responses.
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Neurofibromatosis type 1 (NF1) is a common autosomal dominant disorder. The role of angiogenesis and VEGF pathway in the pathogenesis of neurofibromas and malignant peripheral nerve sheath tumors (MPNSTs) remains poorly understood. We assessed the expression of VEGF and VEGFR family members in cohorts of plexiform neurofibromas (pNF), MPNSTs and MPNST cell lines at transcript [pNF, n = 49; MPNST, n = 34] and protein levels [pNF, n = 21; MPNST, n = 9].

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Adult T-cell leukemia (ATL) is a lymphoid neoplasm caused by human T-cell leukemia virus type 1 (HTLV-1), which encodes the transcriptional activator Tax, which participates in the immortalization of infected T cells. ATL is classified into 4 subtypes: smoldering, chronic, acute, and lymphoma. We determined whether natural killer receptors (NKRs) were expressed in ATL.

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  • Mycosis fungoides (MF) and primary cutaneous CD30-positive T-cell lymphoproliferative disorders (CD30LPD) are common skin lymphomas, and the study aimed to investigate T-cell antigens and PD-1 expression across a large sample of these conditions.
  • The research involved analyzing 160 samples from patients, finding that CD7 was the most frequently lost antigen, especially in MF and CD30LPD, while benign inflammatory dermatoses showed no significant T-cell antigen loss.
  • The study recommends using CD7 alongside other antigen markers like CD3, CD4, and CD8 for diagnosing MF, and suggests employing double staining techniques for more complex cases.
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Subcutaneous panniculitis-like T-cell lymphoma (SPTCL) is a rare but well-defined entity, often associated with autoimmune manifestations, generally with a good prognosis unless associated with hemophagocytic syndrome. Typically, the lymphoma cells rim the adipocytes and are characterized by a CD8 + cytotoxic phenotype. We report 2 cases of SPTCL where the first biopsies only showed subcutaneous fat necrosis without any lymphoma cell visible.

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  • - This study analyzed severe blistering skin reactions caused by immune checkpoint inhibitors (ICI) in 32 patients, emphasizing that such reactions, although rare, can be life-threatening and are often misdiagnosed as epidermal necrolysis (EN).
  • - The research found that symptoms like fever, ocular involvement, and extensive skin detachment were more common in patients diagnosed with EN compared to those with lichenoid dermatosis (LD) or unclassified dermatosis (UD), highlighting the need for careful diagnostic review.
  • - Treatment usually involved corticosteroids, and 25% of patients died during the acute phase; however, most did not restart the ICI, suggesting a potential issue with management approaches that need further consensus and clarity
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Aims: The aim of this multicentre study was to harmonize programmed death-ligand 1 (PD-L1) immunohistochemistry (IHC) and melanoma scoring. To provide a reference for PD-L1 expression independently of the IHC protocol, PD-L1 mRNA expression was compared with IHC.

Methods And Results: Standardized PD-L1 assays (22C3, 28-8, SP142, SP263) and laboratory-developed tests (QR1, 22C3) were evaluated on three IHC platforms with a training set (seven cases).

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