Varicella-zoster virus in actively spreading segmental vitiligo skin: Pathological, immunochemical, and ultrastructural findings (a first and preliminary study).

Segmental vitiligo (SV) is a unilateral subtype of vitiligo which is clinically characterized by a cutaneous depigmentation and histologically by a melanocyte loss from the epidermis and hair follicle reservoirs. To date, its pathogenesis remains a mystery. In many cases, this skin depigmentation shares several clinical features and dysfunctions with herpes zoster (HZ). So, for the first time, we examined whether any nucleus and cell fusion associated with a positive immunolabelling of varicella-zoster virus (VZV) and VZV mature virions could be found in SV skin samples as in herpes zoster (HZ). A total of 40 SV samples were used for histological and immunochemical studies. Control samples were obtained from three HZ, and 10 generalized vitiligo lesions. For ultrastructural study, three recent SV and one HZ as controls were recruited. Here, we report that nuclear fusion in epidermal cells were statistically associated with recent SV (p < .001), whereas syncytia formation was associated with long-lasting SV (p = .001). A positive detection of VZV antigen was statistically associated in the epidermis with recent SV and in the dermis with long-lasting SV (p = .001). Finally, the discovery of mature virions in 3/3 recent SV samples provides additional arguments for our viral hypothesis.

Annular lipoatrophy of the ankle: Four new pediatric cases and a review of the literature.

Annular lipoatrophy of the ankle is a rare and unique acquired lipoatrophic panniculitis that mainly affects children. There is no consensus on treatment, and the long-term course is not well known. We present four new pediatric cases that contribute to the understanding of this rare disease.

In vitro and pilot in vivo imaging of 18 kDa translocator protein (TSPO) in inflammatory vascular disease.

BACKGROUND: Inflammatory vascular disease of the arteries, such as inflamed atheromatous plaques or arteritis, may cause aneurysms or ischemic strokes. In this context, using positron emission tomography (PET) to image inflammation may help select patients who would benefit from appropriate therapeutic interventions. This study sought to assess the usefulness of the 18 kDa translocator protein (TSPO) tracers [11C]-PBR28 and [18F]-PBR06 for imaging inflammatory vascular disease in vitro and in vivo. Immunohistochemistry for macrophage infiltration as well as autoradiography with [18F]-PBR06 were performed on eight paraffin-embedded, formalin-fixed atherosclerosis plaques prospectively collected after carotid endarterectomy of eight patients affected by ischemic stroke. Six different patients, one of whom was also included in the in vitro study, underwent PET imaging. Two patients with carotid stenosis associated with ischemic stroke were imaged with [18F]-PBR06 PET/CT, and four other patients (three with large vessel vasculitis and one with bilateral carotid stenosis but without stroke) were imaged with [11C]-PBR28. RESULTS: All in vitro sections showed specific binding of [18F]-PBR06, which co-localized with immunohistochemistry markers for inflammation. However, in vivo TSPO imaging with either [11C]-PBR28 or [18F]-PBR06 was negative in all participants. CONCLUSION: Despite good uptake on surgical samples in vitro, [11C]-PBR28 and [18F]-PBR06 are not viable clinical tools for imaging inflammatory vascular disease. TRIAL REGISTRATION: NCT02513589, registered 31 July 2015 and NCT00547976, registered 23 October 2007. https://clinicaltrials.gov .

CD154 Induces Interleukin-6 Secretion by Kidney Tubular Epithelial Cells under Hypoxic Conditions: Inhibition by Chloroquine.

Inflammation is a major contributor to tubular epithelium injury in kidney disorders, and the involvement of blood platelets in driving inflammation is increasingly stressed. CD154, the ligand of CD40, is one of the mediators supporting platelet proinflammatory properties. Although hypoxia is an essential constituent of the inflammatory reaction, if and how platelets and CD154 regulate inflammation in hypoxic conditions remain unclear. Here, we studied the control by CD154 of the proinflammatory cytokine interleukin- (IL-) 6 secretion in short-term oxygen (O2) deprivation conditions, using the HK-2 cell line as a kidney tubular epithelial cell (TEC) model. IL-6 secretion was markedly stimulated by CD154 after 1 to 3 hours of hypoxic stress. Both intracellular IL-6 expression and secretion were stimulated by CD154 and associated with a strong upregulation of IL-6 mRNA and increased transcription. Searching for inhibitors of CD154-mediated IL-6 production by HK-2 cells in hypoxic conditions, we observed that chloroquine, a drug that has been repurposed as an anti-inflammatory agent, alleviated this induction. Therefore, CD154 is a potent early stimulus for IL-6 secretion by TECs in O2 deprivation conditions, a mechanism likely to take part in the deleterious inflammatory consequences of platelet activation in kidney tubular injury. The inhibition of CD154-induced IL-6 production by chloroquine suggests the potential usefulness of this drug as a therapeutic adjunct in conditions associated with acute kidney injury.

C5b9 Deposition in Glomerular Capillaries Is Associated With Poor Kidney Allograft Survival in Antibody-Mediated Rejection.

C4d deposition in peritubular capillaries (PTC) reflects complement activation in antibody-mediated rejection (ABMR) of kidney allograft. However, its association with allograft survival is controversial. We hypothesized that capillary deposition of C5b9-indicative of complement-mediated injury-is a severity marker of ABMR. This pilot study aimed to determine the frequency, location and prognostic impact of these deposits in ABMR. We retrospectively selected patients diagnosed with ABMR in two French transplantation centers from January 2005 to December 2014 and performed C4d and C5b9 staining by immunohistochemistry. Fifty-four patients were included. Median follow-up was 52.5 (34.25-73.5) months. Thirteen patients (24%) had C5b9 deposits along glomerular capillaries (GC). Among these, seven (54%) had a global and diffuse staining pattern. Twelve of the C5b9+ patients also had deposition of C4d in GC and PTC. C4d deposits along GC and PTC were not associated with death-censored allograft survival (p = 0.42 and 0.69, respectively). However, death-censored allograft survival was significantly lower in patients with global and diffuse deposition of C5b9 in GC than those with a segmental pattern or no deposition (median survival after ABMR diagnosis, 6 months, 40.5 months and 44 months, respectively; p = 0.015). Double contour of glomerular basement membrane was diagnosed earlier after transplantation in C5b9+ ABMR than in C5b9- ABMR (median time after transplantation, 28 vs. 85 months; p = 0.058). In conclusion, we identified a new pattern of C5b9+ ABMR, associated with early onset of glomerular basement membrane duplication and poor allograft survival. Complement inhibitors might be a therapeutic option for this subgroup of patients.

Malignant triton tumor: Grand Round presentation of a rare aggressive case thoracolumbar spine tumor.

INTRODUCTION: We report a rare and aggressive case of malignant triton tumor (MTT) at the thoracolumbar junction with foraminal extension mistreated as schwannoma. MATERIALS AND METHODS: A 70-year-old man with a 2-year history of lower back pain and left L4 radiculopathy with no history of neurofibromatosis. RESULTS: Pre-operative MRI suggested a typical schwannoma. Upon complete marginal resection, histological findings revealed a MTT. The patient presented with a local and regional recurrence and died 10 months after surgery. MTTs are a subgroup of malignant peripheral nerve sheath tumors, which develop from Schwann cells of peripheral nerves or within existing neurofibromas, and display rhabdomyoblastic differentiation. CONCLUSION: Based on the Grand Round case and relevant literature, we present a case of a highly aggressive and fast-growing tumor with a very high local and distant recurrence. There is no consensus treatment plan available and patients usually die shortly after diagnosis.

Idiopathic Nephrotic Syndrome: Characteristics and Identification of Prognostic Factors.

There are various histopathological forms of idiopathic nephrotic syndrome, including minimal change disease (MCD) and focal segmental glomerulosclerosis (FSGS). Whereas some relapse predictor factors have been identified in renal transplantation, the clinical future of idiopathic nephrotic syndrome in the native kidney remains uncertain. We designed a multicentric retrospective descriptive cohort study including all patients aged 15 years and over whose renal biopsy confirmed MCD or FSGS between January 2007 and December 2014. We studied 165 patients with idiopathic nephrotic syndrome; 97 with MCD and 68 with FSGS. In the MCD cohort, 91.7% of patients were treated with corticosteroids for a median total duration of 13 months. During 45 months of follow-up, 92.8% of patients achieved remission and 45.5% experienced relapse. In this cohort, 5% of patients experienced terminal kidney disease. With respect to FSGS patients, 51.5% were treated with corticosteroids for a median total duration of 15 months. During 66 months of follow-up, 73.5% of patients achieved remission and 20% experienced relapse. In this cohort, 26.5% of patients experienced terminal kidney disease. No statistical association was observed between clinical and biological initial presentation and relapse occurrence. This study describes the characteristics of a cohort of patients with the nephrotic idiopathic syndromes of MCD and FSGS from the time of renal biopsy and throughout follow-up.

Tracking cellular and molecular changes in a species-specific manner during experimental tumor progression in vivo.

Hepatoblastoma (HBL) is a pediatric liver cancer with defined molecular alterations driving its progression. Here, we describe an animal model for HBL on the chick chorioallantoic membrane (CAM), which recapitulates relevant features of HBL in patients. Expression of classic tumor-associated proteins such as ß-catenin, EpCAM and CK19 was maintained in acini-like organized tumors on CAM, as was synthesis of AFP, a tumor marker used for monitoring patient response. RNA sequencing revealed an unexpected molecular evolution of HBL cells on the CAM, with significant deregulation of more than 6,000 genes including more than half of all HOX genes. Bioinformatic analysis distinguish between tumor cell-expressed genes and chick genes, thereby shedding new light on the complex interactions taking place during HBL progression. Importantly, human tumor suppressive ribosomal genes were downregulated after implantation, whereas mitochondrial genes encoding for anti-apoptotic peptides were strongly induced in vivo. Meprin-1α expression was increased during evolution of CAM tumors and confirmed by immunohistochemistry. Cisplatin, a commonly used chemotherapeutic agent for HBL, showed significant anti-tumoral effects. Our results broaden the understanding of the molecular adaptation process of human cancer cells to the microenvironment and might help to elaborate novel therapeutic concepts for the treatment of this pediatric liver tumor.

The disappointing contribution of anti-human leukocyte antigen donor-specific antibodies characteristics for predicting allograft loss.

Background: Pathogenicity of donor-specific antibodies (DSAs) can be assessed using the single-antigen flow beads (SAFB) assays through mean fluorescence intensity (MFI) with or without serum ethylenediaminetetraacetic acid (EDTA) treatment, measurement of C1q or C3d binding and/or their intragraft detection [graft-bound donor-specific antibody (gDSA)]. We aimed to investigate which of these markers best associates with antibody-mediated rejection (ABMR) and kidney allograft loss at the time of a for-cause biopsy. Methods: This retrospective, single-centre study included 77 kidney transplant recipients who underwent a for-cause biopsy between December 2004 and July 2013. All displayed serum DSAs were identified on the same day as the biopsy. Sera were tested in parallel with the classical SAFB assay with or without serum EDTA treatment, C1q- and C3d-binding assays. gDSAs were eluted from biopsy fragments and identified with SAFB. Results: The median time between transplantation and biopsy was 25 months (range 0.5-251). The median follow-up was 36 months (range 0-140). ABMR was histologically proven in 40% of recipients. The sensitivity and specificity of C1q, C3d and gDSA assays for predicting ABMR were 68% and 61%, 52% and 70% and 64.5% and 56.5%, respectively. At the time of biopsy, only the DSA MFI after EDTA treatment and C3d positivity were associated with graft loss. In multivariate analyses, glomerular filtration rate, transplant glomerulopathy and C4d positivity were the only factors associated with graft loss. Conclusions: Our findings weaken the rationale for systematically implementing C1q, C3d or gDSA assays in this situation, because they do not independently predict ABMR and graft loss.

Correction to: Blood platelets and sepsis pathophysiology: A new therapeutic prospect in critically ill patients?

Upon publication of the original article [1], it was noticed that the title was incorrect. Instead of 'critical', it should read 'critically', and therefore, the correct title should be.

Unconventional secretion of FABP4 by endosomes and secretory lysosomes.

An appreciation of the functional properties of the cytoplasmic fatty acid binding protein 4 (FABP4) has advanced with the recent demonstration that an extracellular form secreted by adipocytes regulates a wide range of physiological functions. Little, however, is known about the mechanisms that mediate the unconventional secretion of FABP4. Here, we demonstrate that FABP4 secretion is mediated by a membrane-bounded compartment, independent of the conventional endoplasmic reticulum-Golgi secretory pathway. We show that FABP4 secretion is also independent of GRASP proteins, autophagy, and multivesicular bodies but involves enclosure within endosomes and secretory lysosomes. We highlight the physiological significance of this pathway with the demonstration that an increase in plasma levels of FABP4 is inhibited by chloroquine treatment of mice. These findings chart the pathway of FABP4 secretion and provide a potential therapeutic means to control metabolic disorders associated with its dysregulated secretion.

Idiopathic inflammatory myopathies overlapping with systemic diseases.

A muscle biopsy is currently requested to assess the diagnosis of an idiopathic inflammatory myopathy overlapping with a systemic disease. During the past few years, the classification of inflammatory myopathy subtypes has been revisited progressively on the basis of correlations between clinical phenotypes, autoantibodies and histological data. Several syndromic entities are now more clearly defined, and the aim of the present review is to clarify the contribution of muscle biopsy in a setting of idiopathic inflammatory myopathies overlapping with systemic diseases.
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Blood platelets and sepsis pathophysiology: A new therapeutic prospect in critically [corrected] ill patients?

Beyond haemostasis, platelets have emerged as versatile effectors of the immune response. The contribution of platelets in inflammation, tissue integrity and defence against infections has considerably widened the spectrum of their role in health and disease. Here, we propose a narrative review that first describes these new platelet attributes. We then examine their relevance to microcirculatory alterations in multi-organ dysfunction, a major sepsis complication. Rapid progresses that are made on the knowledge of novel platelet functions should improve the understanding of thrombocytopenia, a common condition and a predictor of adverse outcome in sepsis, and may provide potential avenues for management and therapy.

A Role for CD154, the CD40 Ligand, in Granulomatous Inflammation.

Granulomatous inflammation is a distinctive form of chronic inflammation in which predominant cells include macrophages, epithelioid cells, and multinucleated giant cells. Mechanisms regulating granulomatous inflammation remain ill-understood. CD154, the ligand of CD40, is a key mediator of inflammation. CD154 confers a proinflammatory phenotype to macrophages and controls several macrophagic functions. Here, we studied the contribution of CD154 in a mouse model of toxic liver injury with carbon tetrachloride and a model of absorbable suture graft. In both models, granulomas are triggered in response to endogenous persistent liver calcified necrotic lesions or by grafted sutures. CD154-deficient mice showed delayed clearance of carbon tetrachloride-induced liver calcified necrotic lesions and impaired progression of suture-induced granuloma. In vitro, CD154 stimulated phagocytosis of opsonized erythrocytes by macrophages, suggesting a potential mechanism for the altered granulomatous inflammation in CD154KO mice. These results suggest that CD154 may contribute to the natural history of granulomatous inflammation.

Primary diffuse leptomeningeal gliomatosis: do we miss the diagnosis?

Primary diffuse leptomeningeal gliomatosis (PDLG) is characterized by diffuse infiltration of the leptomeningeal space by neoplastic glial cells without evidence of intra-parenchymatous primary tumor. We report a case of PDLG in a 68-year-old man, who died 1 month after onset of symptoms. The diagnosis was made on autopsy data. We discuss the particularities of this entity, which is not registered in the WHO classification of tumors of the central nervous system (2016). In case of an unexplained inflammatory meningeal process and in the presence of atypical cells in the cerebrospinal fluid, PDLG needs to be considered. This diagnosis of PDLG has to be confirmed by meningeal imaging-guided biopsy, which must be repeated if necessary.
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CD40 signaling and hepatic steatosis: Unanticipated links.

Obesity predisposes to an increased risk of nonalcoholic fatty liver disease (NAFLD). Hepatic steatosis is the key pathological feature of NAFLD and has emerged as a metabolic disorder in which innate and adaptive arms of the immune response play a central role in disease pathogenesis. Recent studies have revealed unexpected relationships between CD40 signaling and hepatic steatosis in high fat diet rodent models. CD154, the ligand of CD40, is a mediator of inflammation and controls several critical events of innate and adaptive immune responses. In the light of these reports, we discuss potential links between CD40 signaling and hepatic steatosis in NAFLD.

[Reticular perineurioma of the tibial nerve]. / Périneuriome réticulaire du nerf tibial.

Reticular (retiform) perineurioma is a rare variant of soft tissue perineurioma developed from the perineurium. This benign tumor is characterized by strands of spindle cells in a fibro-myxoid matrix surrounding pseudocystic mucoid spaces. We report a tibial nerve reticular perineurioma in a 35-year-old patient.

CD154 Induces Matrix Metalloproteinase-9 Secretion in Human Podocytes.

Matrix remodeling is a key feature of glomerulosclerosis secondary to diabetes or hypertension. Podocytes contribute to glomerular basement membrane (GBM) turnover by producing matrix components and matrix remodelling enzymes, including matrix metalloproteinases (MMPs). The CD40/CD154 signaling pathway modulates matrix remodeling through the synthesis of MMPs and tissue inhibitors of MMPs. Platelets are a primary blood reservoir of CD154. Here we studied, the impact of the CD154/CD40 pathway on MMP-9 expression by cultured human podocytes. The role of CD40/CD154 was evaluated upon exposure of podocytes to recombinant human CD154 (rhCD154) or activated platelet supernatants from healthy human subjects. We first showed by protein and mRNA expression that CD40 was synthesized by podocytes and detectable on kidney tissue sections. CD40 expression was acquired during podocyte differentiation and enhanced upon exposure to rhCD154. In podocytes, rhCD154 induced an increase of MMP-9 production as shown by RT-PCR, Western blot and and gelatin zymography. Activated platelet supernatants induced MMP-9 mRNA synthesis in podocytes, an effect reduced by anti-CD40 antibody. Our results underscore a potential role for platelets through the CD40/CD154 signaling pathway in the control of GBM synthesis and degradation, via its regulatory role on MMP-9 production. CD154 secretion by activated platelets may contribute to GBM alterations in proteinuric nephropathies. J. Cell. Biochem. 117: 2737-2747, 2016. © 2016 Wiley Periodicals, Inc.

A new subtype of high-grade mandibular osteosarcoma with RASAL1/MDM2 amplification.

In contrast to long bone osteosarcoma, mandibular osteosarcoma is highly heterogeneous and morphologically overlaps with benign tumors, obscuring diagnosis and treatment selection. Molecular characterization is difficult due to the paucity of available specimens of this rare disease. We aimed to characterize the spectrum of mandibular osteosarcoma using immunohistochemistry and molecular techniques (quantitative polymerase chain reaction and sequencing) and compare them with benign fibro-osseous lesions. Forty-nine paraffin-embedded mandible osteosarcoma tissue samples were collected retrospectively and compared with 10 fibrous dysplasia and 15 ossifying fibroma cases. These were analyzed for molecular markers thought to differ between the different diseases and subtypes: MDM2 (murine double-minute type 2) overexpression, GNAS (guanine nucleotide-binding protein/α subunit) mutations, and amplification of MDM2 and/or RASAL1 (RAS protein activator like 1). Five fibroblastic high-grade osteosarcoma subtypes showed MDM2 amplification, including 2 with a microscopic appearance of high-grade osteosarcoma with part low-grade osteosarcoma (differentiated/dedifferentiated osteosarcoma) and MDM2 overexpression. The other 3 contained a coamplification of MDM2 and RASAL1, a signature also described for juvenile ossifying fibroma, with no overexpression of MDM2. These were of the giant cell-rich high-grade osteosarcoma, with areas mimicking juvenile ossifying fibroma (ossifying fibroma-like osteosarcoma). Our results show that some diagnosed high-grade osteosarcomas are differentiated/dedifferentiated osteosarcomas and harbor an overexpression and amplification of MDM2. In addition, juvenile ossifying fibromas can potentially evolve into giant cell-rich high-grade osteosarcomas and are characterized by a RASAL1 amplification (osteosarcoma with juvenile ossifying fibroma-like genotype). Thus, the presence of a RASAL1 amplification in ossifying fibroma may indicate a requirement for closer follow-up and more aggressive management.