Type-I interferons promote innate immune tolerance in macrophages exposed to Mycobacterium ulcerans vesicles.

Buruli ulcer is a chronic infectious disease caused by Mycobacterium ulcerans. The pathogen persistence in host skin is associated with the development of ulcerative and necrotic lesions leading to permanent disabilities in most patients. However, few of diagnosed cases are thought to resolve through an unknown self-healing process. Using in vitro and in vivo mouse models and M. ulcerans purified vesicles and mycolactone, we showed that the development of an innate immune tolerance was only specific to macrophages from mice able to heal spontaneously. This tolerance mechanism depends on a type I interferon response and can be induced by interferon beta. A type I interferon signature was further detected during in vivo infection in mice as well as in skin samples from patients under antibiotics regiment. Our results indicate that type I interferon-related genes expressed in macrophages may promote tolerance and healing during infection with skin damaging pathogen.

Association between kinetic of anti-neutrophil cytoplasmic antibody (ANCA), renal survival and relapse risk in ANCA glomerulonephritis.

BACKGROUND: Anti-neutrophil cytoplasmic antibody (ANCA) kinetic in ANCA-associated vasculitis with glomerulonephritis (AAV-GN) has been suggested to be associated with AAV relapse. Few studies have focused on its association with renal prognosis. Thus we aimed to investigate the relationship between ANCA specificity and the evolutive profile and renal outcomes. METHODS: This multicentric retrospective study included patients diagnosed with ANCA-GN since 1 January 2000. Patients without ANCA at diagnosis and with fewer than three ANCA determinations during follow-up were excluded. We analysed estimated glomerular filtration rate (eGFR) variation, renal-free survival and relapse-free survival according to three ANCA profiles (negative, recurrent and persistent) and to ANCA specificity [myeloperoxidase (MPO) or proteinase 3 (PR3)]. RESULTS: Over a follow-up of 56 months [interquartile range (IQR) 34-101], a median of 19 (IQR 13-25) ANCA determinations were performed for the 134 included patients. Patients with a recurrent/persistent ANCA profile had a lower relapse-free survival (P = .019) and tended to have a lower renal survival (P = .053) compared with those with a negative ANCA profile. Patients with a recurrent/persistent MPO-ANCA profile had the shortest renal survival (P = .015) and those with a recurrent/persistent PR3-ANCA profile had the worst relapse-free survival (P = .013) compared with other profiles. The negative ANCA profile was associated with a greater eGFR recovery. In multivariate regression analysis, it was an independent predictor of a 2-fold increase in eGFR at 2 years [odds ratio 6.79 (95% confidence interval 1.78-31.4), P = .008]). CONCLUSION: ANCA kinetic after an ANCA-GN diagnosis is associated with outcomes. MPO-ANCA recurrence/persistence identifies patients with a lower potential of renal recovery and a higher risk of kidney failure, while PR3-ANCA recurrence/persistence identifies patients with a greater relapse risk. Thus ANCA kinetics may help identify patients with a smouldering disease.

Lymphopaenia at diagnosis of anti-neutrophil cytoplasmic antibody-vasculitis with renal involvement is correlated with severity and renal prognosis.

BACKGROUND: Lymphopaenia is commonly observed in autoimmune diseases, where it has been associated with disease activity or prognosis. However, in anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) only a few small-scale studies have been targeted towards this issue. Research has not yet focused on AAV with renal involvement (AAV-RI). Thus the aim of this study was to analyse the association between lymphocyte counts and outcomes in a large cohort of AAV-RI patients. METHODS: We used the Maine-Anjou AAV registry that retrospectively gathers data on consecutive patients affected by AAV in four French nephrology centres, recorded since January 2000. We analysed clinical, biological and histological data at diagnosis of AAV-RI. Risk factors for end-stage kidney disease (ESKD) were analysed. Event-free survival was also assessed. RESULTS: Among the 145 patients included in the study, those with lymphopaenia at diagnosis had a lower renal function at baseline [estimated glomerular filtration rate (eGFR) 13 versus 26 mL/min; P = 0.002] and were more likely to require kidney replacement therapy (51% versus 25%; P = 0.003). Lymphopaenia was correlated with histological lesions and especially with the percentage of sclerotic glomeruli (P = 0.0027). ESKD-free survival was lower in lymphopaenic patients (P < 0.0001). In multivariate Cox analysis, lymphopaenia was an independent risk factor for ESKD [hazard ratio 4.47 (95% confidence interval 2.06-9.72), P < 0.001]. CONCLUSIONS: Lymphopaenia correlates with the severity of AAV glomerulonephritis at diagnosis and predicts poor renal outcome. In this view, lymphopaenia could be used as a simple and cost-effective biomarker to assess renal prognosis at AAV-RI diagnosis.

Lessons from a large nationwide cohort of 350 children with ovarian mature teratoma: A study in favor of ovarian-sparing surgery.

BACKGROUND: Ovarian mature teratoma (OMT) is a common ovarian tumor found in the pediatric population. In 10%-20% of cases, OMT occurs as multiple synchronous or metachronous lesions on ipsi- or contralateral ovaries. Ovarian-sparing surgery (OSS) is recommended to preserve fertility, but total oophorectomy (TO) is still performed. DESIGN: This study reviews the clinical data of patients with OMT, and analyzes risk factors for second events. A national retrospective review of girls under 18 years of age with OMTs was performed. Data on clinical features, imaging, laboratory studies, surgical reports, second events and their management were retrieved. RESULTS: Overall, 350 children were included. Eighteen patients (5%) presented with a synchronous bilateral form at diagnosis. Surgery was performed by laparotomy (85%) and laparoscopy (15%). OSS and TO were performed in 59% and 41% of cases, respectively. Perioperative tumor rupture occurred in 23 cases, independently of the surgical approach. Twenty-nine second events occurred (8.3%) in a median time of 30.5 months from diagnosis (ipsilateral: eight cases including one malignant tumor; contralateral: 18 cases; both ovaries: three cases). A large palpable mass, bilateral forms, at diagnosis and perioperative rupture had a statistical impact on the risk of second event, whereas the type of surgery or approach did not. CONCLUSION: This study is a plea in favor of OSS as the first-choice treatment of OMT when possible. Close follow-up during the first 5 years is mandatory considering the risk of 8.3% of second events, especially in cases with risk factors.

Ketogenic Diet Impairment of Mycobacterium ulcerans Growth and Toxin Production and Enhancement of Host Response to Infection in an Experimental Mouse Model.

Ketogenic diets have been used to treat diverse conditions, and there is growing evidence of their benefits for tissue repair and in inflammatory disease treatment. However, their role in infectious diseases has been little studied. Buruli ulcer (Mycobacterium ulcerans infection) is a chronic infectious disease characterized by large skin ulcerations caused by mycolactone, the major virulence factor of the bacillus. In the current study, we investigated the impact of ketogenic diet on this cutaneous disease in an experimental mouse model. This diet prevented ulceration, by modulating bacterial growth and host inflammatory response. ß-hydroxybutyrate, the major ketone body produced during ketogenic diet and diffusing in tissues, impeded M. ulcerans growth and mycolactone production in vitro underlying its potential key role in infection. These results pave the way for the development of new patient management strategies involving shorter courses of treatment and improving wound healing, in line with the major objectives of the World Health Organization.

Primary cutaneous large B-cell lymphomas: relevance of the 2017 World Health Organization classification: clinicopathological and molecular analyses of 64 cases.

AIMS: We applied the 2017 World Health Organization (WHO) classification criteria to categorise a series of 64 primary cutaneous large B-cell lymphomas (PCLBCLs), containing a majority (≥80%) of large cells and a proliferative rate of ≥40%, raising the problem of the differential diagnosis between PCLBCL, leg type (PCLBCL-LT) and primary cutaneous follicle centre lymphoma, large cell (PCFCL-LC). The aims were to determine the reproducibility and prognostic relevance of the 2017 WHO criteria. METHODS AND RESULTS: Morphology and phenotype identified 32 PCLBCLs-LT and 25 PCFCLs-LC; seven cases (11%) remained unclassified. Morphology was less reproducible than immunophenotype. Pertinent markers for the differential diagnosis were MUM1, FOXP1, CD10, and IgM. bcl-2 and bcl-6 were expressed by both PCFCLs-LC and PCLBCLs-LT at substantial levels. Neither Ki67 expression nor p63 expression was of diagnostic value. MYD88 was found to be mutated only in PCLBCLs-LT (n = 22, 69%). According to Hans/Hans modified algorithms, 23 of 25 PCFCLs-LC had germinal centre (GC) status, and the 32 PCLBCLs-LT had non-GC status. Overall survival was poorer for PCLBCLs-LT than PCFCLs-LC (P = 0.0002). Non-GC cases had poorer overall survival than GC cases (P = 0.0007). In PCLBCLs-LT, MYC expression was associated with cutaneous relapses (P = 0.014). When GC/non-GC status was applied to unclassified cases, only a single case remained discordant. CONCLUSIONS: Our results support the 2017 WHO classification criteria for PCLBCL diagnosis. The Hans modified algorithm using CD10 and MUM1 distinguished PCFCLs-LC from PCLBCLs-LT with optimal diagnostic value without requiring bcl-6 immunolabelling (poorly reproducible). Rare unclassified cases may constitute a provisionally heterogeneous subgroup for which GC/non-GC status (relevant for prognosis) may guide therapeutic decisions.

IL-26 Confers Proinflammatory Properties to Extracellular DNA.

In physiological conditions, self-DNA released by dying cells is not detected by intracellular DNA sensors. In chronic inflammatory disorders, unabated inflammation has been associated with a break in innate immune tolerance to self-DNA. However, extracellular DNA has to complex with DNA-binding molecules to gain access to intracellular DNA sensors. IL-26 is a member of the IL-10 cytokine family, overexpressed in numerous chronic inflammatory diseases, in which biological activity remains unclear. We demonstrate in this study that IL-26 binds to genomic DNA, mitochondrial DNA, and neutrophil extracellular traps, and shuttles them in the cytosol of human myeloid cells. As a consequence, IL-26 allows extracellular DNA to trigger proinflammatory cytokine secretion by monocytes, in a STING- and inflammasome-dependent manner. Supporting these biological properties, IL-10-based modeling predicts two DNA-binding domains, two amphipathic helices, and an in-plane membrane anchor in IL-26, which are structural features of cationic amphipathic cell-penetrating peptides. In line with these properties, patients with active autoantibody-associated vasculitis, a chronic relapsing autoimmune inflammatory disease associated with extensive cell death, exhibit high levels of both circulating IL-26 and IL-26-DNA complexes. Moreover, in patients with crescentic glomerulonephritis, IL-26 is expressed by renal arterial smooth muscle cells and deposits in necrotizing lesions. Accordingly, human primary smooth cells secrete IL-26 in response to proinflammatory cytokines. In conclusion, IL-26 is a unique cationic protein more similar to a soluble pattern recognition receptor than to conventional cytokines. IL-26 expressed in inflammatory lesions confers proinflammatory properties to DNA released by dying cells, setting up a positive amplification loop between extensive cell death and unabated inflammation.

Clinico-pathological considerations in a 48-years-old female with acute kidney injury: is it lupus nephritis, ANCA-associated vasculitis or something else?

BACKGROUND: The value of ANCA positivity in the setting of systemic lupus erythematous and their pathogenicity remains uncertain. CASE PRESENTATION: We report the case of a 48-year-old female with rapidly progressive kidney failure, arthro-myalgia and weight loss. Auto-immune screening showed anti-dsDNA antibodies, complement consumption and triple ANCA positivity. A first kidney biopsy done at presentation highlighted class IV-G glomerulonephritis with elective extra-capillary involvement and mainly C1q glomerular deposition at immunofluorescence study. After three months of a regimen combining steroids and cyclophosphamide, a second biopsy was performed and showed class IV-G glomerulonephritis with mainly endocapillary proliferation. CONCLUSION: This case is atypical in view of immunological profile and kidney histopathological presentation and evolution and gives rise to discussion in view of recent data on ANCA value in lupus nephritis, and suggests that different auto-immune pathways may be involved in lupus nephritis.

[An atypical case of lipoid proteinosis]. / Un cas atypique de protéinose lipoïde.

The lipoid proteinosis is a rare autosomic recessive genodermatosis characterized histologically by deposits of hyaline-like eosinophilic material of characteristic distribution. We herein report the case of a 56-year-old man admitted for progressive aggravated dementia associated with a late-onset dysphonia. Histologic examination of cutaneous and laryngeal biopsies showed deposits of an amorphous and eosinophilic material arranged around vessels, and adnexal structures, stained by PAS and congo red negative. The detection of a mutation in the ECM1 gene confirmed the diagnosis of lipoid proteinosis of atypical clinical presentation.

IL-34 and macrophage colony-stimulating factor are overexpressed in hepatitis C virus fibrosis and induce profibrotic macrophages that promote collagen synthesis by hepatic stellate cells.

UNLABELLED: Chronic hepatitis C virus (HCV) infection is characterized by progressive hepatic fibrosis, a process dependent on monocyte recruitment and accumulation into the liver. The mediators expressed in chronically injured liver that control the differentiation of human monocytes into profibrotic macrophages (Mφ) remain poorly defined. We report that chronically HCV-infected patients with high fibrosis stages have higher serum levels of macrophage colony-stimulating factor (M-CSF) and interleukin (IL)-34 than HCV-infected patients with lower fibrosis stages and healthy subjects. Immunohistochemistry reveals an intense expression of IL-34 and M-CSF by hepatocytes around liver lesions. In addition, HCV infection and inflammatory cytokines enhance the in vitro production of IL-34 and M-CSF by hepatocytes. We next analyzed the acquisition of profibrotic properties by Mφ generated with M-CSF (M-CSF-Mφ) or IL-34 (IL-34-Mφ). M-CSF and IL-34 up-regulate the expression, by differentiating monocytes, of chemokine (C-C motif) ligand (CCL)2, CCL4, C-C chemokine receptor (CCR)1, and CCR5, which are involved in monocyte recruitment/Mφ accumulation in liver lesions. M-CSF-Mφ and IL-34-Mφ also express the hepatic stellate cell (HSC) activators, platelet-derived growth factor, transforming growth factor beta, and galectin-3. IL-34-Mφ and M-CSF-Mφ induce type I collagen synthesis by HSCs, the main collagen-producing cells in liver fibrosis. IL-13, whose expression correlates with the fibrosis stage in HCV-infected patients, decreases the expression of the collagenase, matrix metalloproteinase 1, by IL-34-Mφ and M-CSF-Mφ, thereby enhancing collagen synthesis. By inhibiting the production of interferon-gamma (IFN-γ) by activated natural killer cells, IL-34-Mφ and M-CSF-Mφ prevent the IFN-γ-induced killing of HSCs. CONCLUSION: These results identify M-CSF and IL-34 as potent profibrotic factors in HCV liver fibrosis.