Interleukin-33 Amplifies Human Mast Cell Activities Induced by Complement Anaphylatoxins.

Both, aberrant mast cell responses and complement activation contribute to allergic diseases. Since mast cells are highly responsive to C3a and C5a, while Interleukin-33 (IL-33) is a potent mast cell activator, we hypothesized that IL-33 critically regulates mast cell responses to complement anaphylatoxins. We sought to understand whether C3a and C5a differentially activate primary human mast cells, and probe whether IL-33 regulates C3a/C5a-induced mast cell activities. Primary human mast cells were generated from peripheral blood precursors or isolated from healthy human lung tissue, and mast cell complement receptor expression, degranulation, mediator release, phosphorylation patterns, and calcium flux were assessed. Human mast cells of distinct origin express constitutively higher levels of C3aR1 than C5aR1, and both receptors are downregulated by anaphylatoxins. While C3a is a potent mast cell degranulation inducer, C5a is a weaker secretagogue with more delayed effects. Importantly, IL-33 potently enhances the human mast cell reactivity to C3a and C5a (degranulation, cytokine and chemokine release), independent of changes in C3a or C5a receptor expression or the level of Ca2+ influx. Instead, this reflects differential dynamics of intracellular signaling such as ERK1/2 phosphorylation. Since primary human mast cells respond differentially to anaphylatoxin stimulation, and that IL-33 is a key regulator of mast cell responses to complement anaphylatoxins, this is likely to aggravate Th2 immune responses. This newly identified cross-regulation may be important for controlling exacerbated complement- and mast cell-dependent Th2 responses and thus provides an additional rationale for targeting anti-IL33 therapeutically in allergic diseases.

Registration of the extracellular matrix components constituting the fibroblastic focus in idiopathic pulmonary fibrosis.

The extracellular matrix (ECM) in idiopathic pulmonary fibrosis (IPF) drives fibrosis progression; however, the ECM composition of the fibroblastic focus (the hallmark lesion in IPF) and adjacent regions remains incompletely defined. Herein, we serially sectioned IPF lung specimens constructed into tissue microarrays and immunostained for ECM components reported to be deregulated in IPF. Immunostained sections were imaged, anatomically aligned, and 3D reconstructed. The myofibroblast core of the fibroblastic focus (defined by collagen I, α-smooth muscle actin, and procollagen I immunoreactivity) was associated with collagens III, IV, V, and VI; fibronectin; hyaluronan; and versican immunoreactivity. Hyaluronan immunoreactivity was also present at the fibroblastic focus perimeter and at sites where early lesions appear to be forming. Fibrinogen immunoreactivity was often observed at regions of damaged epithelium lining the airspace and the perimeter of the myofibroblast core but was absent from the myofibroblast core itself. The ECM components of the fibroblastic focus were distributed in a characteristic and reproducible manner in multiple patients. This information can inform the development of high-fidelity model systems to dissect mechanisms by which the IPF ECM drives fibrosis progression.

X-linked Inhibitor of Apoptosis Complicated by Granulomatous Lymphocytic Interstitial Lung Disease (GLILD) and Granulomatous Hepatitis.

The X-linked inhibitor of apoptosis (XIAP) deficiency is a primary immunodeficiency characterized by Epstein-Barr virus (EBV)-driven hemophagocytic lymphohistiocytosis (HLH), splenomegaly, and colitis. Here, we present, for the first time, granulomatous hepatitis and granulomatous and lymphocytic interstitial lung disease (GLILD) as manifestations of XIAP deficiency. We report successful treatment of GLILD in XIAP deficiency with rituximab and azathioprine and discuss the role of XIAP deficiency in immune dysregulation.

Follicular dendritic cell tumour/sarcoma: a commonly misdiagnosed tumour in the thorax.

AIMS: Follicular dendritic cell sarcoma is a rare tumour reported to occur occasionally in association with the hyaline-vascular type of Castleman's disease (HVCD). Most cases arise in lymph nodes, although extranodal presentation is described. METHODS AND RESULTS: Clinical, radiological and histological characteristics, including diagnosis on pre-resection material, were assessed in seven intrathoracic cases from five males and two females with a median age of 38 years. Clinical symptoms were related to mass location, six cases presenting within central and/or posterior mediastinal compartments and one within the lungs. Positron emission tomography-computed tomography demonstrated marked fluoro-deoxy-glucose avidity and the prominent vessels traversing the lesions. Four of six cases (67%) were misdiagnosed initially. HVCD was present in three cases. Two cases with high mitotic rates recurred after resection. All were positive for at least one of the follicular dendritic cell markers (CD21, CD35 and CD23). Six of seven cases (86%) show cyclin D1 expression ranging from 5% to 90%. CONCLUSIONS: Follicular dendritic cell sarcoma is often misdiagnosed on biopsy and pathologists need to be aware of the tumour to request the relevant immunohistochemistry, especially in masses presenting in the central/posterior mediastinum with high vascularity and standardized uptake values. Background HVCD appears more common than previously thought.

Bombesin staining in neuroendocrine cell hyperplasia of infancy (NEHI) and other childhood interstitial lung diseases (chILD).

AIMS: We have analysed levels of bombesin-positive neuroendocrine cells (NECs) in neuroendocrine cell hyperplasia of infancy (NEHI) and other childhood interstitial lung diseases (chILDs) in order to validate proposed histological criteria for NEHI and investigate its aetiology. METHODS AND RESULTS: The extent of bombesin-positive cells within airway epithelium was analysed in lung biopsies from seven patients diagnosed with NEHI, including two classified previously as non-diagnostic, and other chILDs (n = 64) with age ranges of 1 month-18 years. NECs were counted and calculated as a percentage of airways containing NECs, average percentage of NECs per airway, percentage of airways with >10% NECs and number of neuroendocrine bodies (NEBs). Correlation with age and gender was also undertaken. Patients with NEHI had the highest average percentage of bombesin-positive NECs per airway compared to other chILDs. However, NEH was also seen in many other chILDs, and appears to be most prominent in disorders associated with lung immaturity such as histological patterns associated with surfactant protein-related disorders and pulmonary interstitial glycogenosis. CONCLUSIONS: NEH may, to a degree, be a marker of airway immaturity rather than the direct cause of NEHI. This possibility is supported by the fact that the number of bombesin-positive NECs decreased with age in this cohort, independent of disease type. The average percentage of bombesin-positive NECs per airway appears to be the best histological criterion for assessing the extent of NECs in the context of NEHI.

The reproducibility and predictive value on outcome of renal biopsies from expanded criteria donors.

Reproducibility and predictive value on outcome are the main criteria to evaluate the utility of histological scores. Here we analyze the reproducibility of donor biopsy assessment by different on-call pathologists and the retrospective evaluation by a single renal pathologist blinded to clinical outcomes. We also evaluate the predictive value on graft outcome of both evaluations. A biopsy was performed in donors with any of the following: age≥55 years, hypertension, diabetes, creatinine>1.5 mg/dl, or stroke. Glomerulosclerosis, interstitial fibrosis, tubular atrophy, intimal thickening, and arteriolar hyalinosis evaluated according to the Banff criteria were added to obtain a chronic score. Biopsies were classified as mild (≥3), intermediate (4-5), or advanced (6-7) damage, and unacceptable (≥8) for transplantation of 127 kidneys biopsied. Weighted κ value between both readings was 0.41 (95% CI: 0.28-0.54). Evaluation of biopsies by the renal pathologist was significantly and independently associated with estimated 12-month glomerular filtration rate and a significant composite outcome variable, including death-censored graft survival and time to reach an estimated glomerular filtration rate<30 ml/min per 1.73 m2. Thus, there was no association between readings of on-call pathologists and outcome. The lack of association between histological scores obtained by the on-call pathologists and graft outcome suggests that a specific training on renal pathology is recommended to optimize the use of kidneys retrieved from expanded criteria donors.

[Krukenberg's tumor as the first clinical manifestation of fibrolamellar hepatocarcinoma]. / Tumor de Krukenberg como manifestación inicial de hepatocarcinoma fibrolamelar.

Krukenberg's tumor refers to unilateral or bilateral ovarian metastatic tumors whose origin may be known or unknown. The incidence of this type of tumor is difficult to evaluate but may represent between 3% and 8% of ovarian tumors. In most cases, the primary tumor is identified and is usually digestive (basically gastric or colorectal). There are some references to primary hepatic tumors (gall bladder tumor and hepatocarcinoma) but none to fibrolamellar hepatocarcinoma as the primary tumor. We present the case of a 45-year-old woman who presented with lower hemiabdominal pain and who was diagnosed with Krukenberg's tumor of hepatic origin. Although ovarian involvement in primary digestive tumors is possible, hepatic origin is rare.

Tumor de Krukenberg como manifestación inicial de hepatocarcinoma fibrolamelar / Krukenberg’s tumor as the first clinical manifestation of fibrolamellar hepatocarcinoma

El tumor de Krukenberg supone una variedad de cáncer metastático que infiltra de manera unilateral o bilateral el ovario, cuyo origen puede ser conocido o no. Su incidencia es difícil de evaluar, pero se estima que varía entre el 3 y el 8% de los tumores de ovario. En la mayoría de los casos se reconoce el tumor primario; éste es de origen digestivo (sobre todo gástrico o colorrectal). Hay alguna referencia al tumor primario hepático (vesícula biliar y hepatocarcinoma), pero ninguna al tumor de Krukenberg cuyo tumor primario hepático sea un hepatocarcinoma fibrolamelar. Presentamos el caso de una paciente de 45 años de edad, que presentó un dolor en hemiabdomen inferior, diagnosticado de tumor de Krukenberg de origen hepático. Aunque es posible la afectación ovárica como signo inicial de tumores digestivos, el origen hepático es raro

Krukenberg’s tumor refers to unilateral or bilateral ovarian metastatic tumors whose origin may be known or unknown. The incidence of this type of tumor is difficult to evaluate but may represent between 3% and 8% of ovarian tumors. In most cases, the primary tumor is identified and is usually digestive (basically gastric or colorectal). There are some references to primary hepatic tumors (gall bladder tumor and hepatocarcinoma) but none to fibrolamellar hepatocarcinoma as the primary tumor. We present the case of a 45-year-old woman who presented with lower hemiabdominal pain and who was diagnosed with Krukenberg’s tumor of hepatic origin. Although ovarian involvement in primary digestive tumors is possible, hepatic origin is rare (AU)