Procoagulant phenotype of virus-infected pericytes is associated with portal thrombosis and intrapulmonary vascular dilations in fatal COVID-19.

BACKGROUND & AIMS: Mechanisms and clinical impact of portal microthrombosis featuring severe COVID-19 are unknown. Intrapulmonary vascular dilation (IPVD)-related hypoxia has been described in severe liver diseases. We hypothesized that portal microthrombosis is associated with IPVD and fatal respiratory failure in COVID-19. METHODS: Ninety-three patients who died from COVID-19, were analysed for portal microvascular damage (histology), IPVD (histology and chest-computed tomography, CT), and hypoxemia (arterial blood gas). Seventeen patients who died from COVID-19-unrelated pneumonia served as controls. Vascular lesions and microthrombi were phenotyped for endothelial (vWF) and pericyte (αSMA/PDGFR-ß) markers, tissue factor (TF), viral spike-protein and nucleoprotein (SP, NP), fibrinogen, platelets (CD41a). Viral particles in vascular cells were assessed by transmission electron microscopy (TEM). Cultured pericytes were infected with SARS-CoV-2 to measure TF expression and tubulisation of human pulmonary microvascular endothelial cells (HPMEC) was assessed upon vWF treatment. RESULTS: IPVD was present in 16/66 COVID-19 patients with both liver and lung histology, with a younger age (62 vs 78yo), longer illness (25 vs 14 days), worsening hypoxemia (PaO2/FiO2 from 209 to 89), and more ventilatory support (63 vs 22%) compared to COVID-19/Non-IPVD. IPVD, absent in controls, were confirmed by chest-CT. COVID-19/IPVD liver histology showed portal microthrombosis in >82.5% of portal areas, with a thicker wall of αSMA/PDGFR-ß+/ SP+/NP+ pericytes compared with COVID-19/Non-IPVD. Thrombosed portal venules correlated with αSMA+ area, whereas infected SP+/NP+ pericytes expressed TF. SARS-CoV-2 viral particles were observed in portal pericytes. In-vitro SARS-CoV-2 infection of pericytes up-regulated TF and induced endothelial cells to overexpress vWF, which expanded HPMEC tubules. CONCLUSIONS: SARS-CoV-2 infection of liver pericytes elicits a local procoagulant response associated with extensive portal microthrombosis, IPVD and worsening respiratory failure in fatal COVID-19. IMPACT AND IMPLICATIONS: Vascular involvement of the liver represents a serious complication of COVID-19 infection that must be considered in the work-up of patients with long-lasting and progressively worsening respiratory failure, as it may associate with the development of intrapulmonary vascular dilations. This clinical picture is associated with a pro-coagulant phenotype of portal venule pericytes, which is induced by SARS-CoV-2 infection of pericytes. Both observations provide a model that may apply, at least in part, to other vascular disorders of the liver, featuring obliterative portal venopathy, similarly characterized at the clinical level by development of hypoxemia and at the histological level, by phlebosclerosis and reduced caliber of the portal vein branches in the absence of cirrhosis. Moreover, our findings bring light to an as yet overlooked player of thrombosis pathophysiology, i.e. pericytes, which may provide novel therapeutic tools to halt prothrombotic mechanisms.

Granular cell tumor of the neurohypophysis presenting as a third ventricle mass.

Granular cell tumors of the neurohypophysis (GCT) are rare benign neoplasms belonging, along with pituicytoma and spindle cell oncocytoma, to the family of TTF1-positive low-grade neoplasms of the posterior pituitary gland. GCT usually present as a solid sellar mass, slowly growing and causing compressive symptoms over time, occasionally with suprasellar extension. They comprise polygonal monomorphous cells with abundant granular cytoplasm, which is ultrastructurally filled with lysosomes. Here we report the case of a GCT presenting as a third ventricle mass, radiologically mimicking chordoid glioma, with aberrant expression of GFAP and Annexin-A, which lends itself as an example of an integrated diagnostic approach to sellar/suprasellar and third ventricle masses.

The presence of BBB hastens neuronal differentiation of cerebral organoids - The potential role of endothelial derived BDNF.

Despite remaining the best in vitro model to resemble the human brain, a weakness of human cerebral organoids is the lack of the endothelial component that in vivo organizes in the blood brain barrier (BBB). Since the BBB is crucial to control the microenvironment of the nervous system, this study proposes a co-culture of BBB and cerebral organoids. We utilized a BBB model consisting of primary human brain microvascular endothelial cells and astrocytes in a transwell system. Starting from induced Pluripotent Stem Cells (iPSCs) we generated human cerebral organoids which were then cultured in the absence or presence of an in vitro model of BBB to evaluate potential effects on the maturation of cerebral organoids. By morphological analysis, it emerges that in the presence of the BBB the cerebral organoids are better organized than controls in the absence of the BBB. This effect might be due to Brain Derived Neurotrophic Factor (BDNF), a neurotrophic factor released by the endothelial component of the BBB, which is involved in neurodevelopment, neuroplasticity and neurosurvival.

Myoid gonadal tumor. Case series, systematic review, and Bayesian analysis.

Myoid gonadal stromal tumor represents a rare testicular neoplasm displaying smooth muscular and gonadal stromal differentiation. This entity has very few cases reported in the literature that describe heterogeneous clinical and pathological characteristics. Bayesian statistics provides a useful framework to combine information from diverse sources. We here presented a case series-the largest so far reported-of myoid gonadal stromal tumor (4 cases) with extensive morphologic, immunohistochemical, and molecular characterization, performed a systematic review of the literature (that identified 9 papers), and used a Bayesian data analysis to understand the characteristics of this disease. Our study collectively described 16 cases. This neoplasm is mainly found in adults (mean age about 40 years) and often has a size of about 3 cm. By morphology, the tumor can infiltrate testicular tubules and is composed of spindle cells; few mitoses can be seen (usually 2/10 HPF). Neoplastic cells are diffusely positive with α-smooth muscle actin with a tram-track staining pattern. S100 protein, FOXL2, and SF1 are also characteristically positive. Moreover, this neoplasm can display epithelial differentiation, in about half of the cases. In conclusion, we foresee the use of this statistical approach in pathology: our analysis allowed a more precise description of this rare entity.

Pulmonary post-mortem findings in a series of COVID-19 cases from northern Italy: a two-centre descriptive study.

BACKGROUND: COVID-19 is characterised by respiratory symptoms, which deteriorate into respiratory failure in a substantial proportion of cases, requiring intensive care in up to a third of patients admitted to hospital. Analysis of the pathological features in the lung tissues of patients who have died with COVID-19 could help us to understand the disease pathogenesis and clinical outcomes. METHODS: We systematically analysed lung tissue samples from 38 patients who died from COVID-19 in two hospitals in northern Italy between Feb 29 and March 24, 2020. The most representative areas identified at macroscopic examination were selected, and tissue blocks (median seven, range five to nine) were taken from each lung and fixed in 10% buffered formalin for at least 48 h. Tissues were assessed with use of haematoxylin and eosin staining, immunohistochemical staining for inflammatory infiltrate and cellular components (including staining with antibodies against CD68, CD3, CD45, CD61, TTF1, p40, and Ki-67), and electron microscopy to identify virion localisation. FINDINGS: All cases showed features of the exudative and proliferative phases of diffuse alveolar damage, which included capillary congestion (in all cases), necrosis of pneumocytes (in all cases), hyaline membranes (in 33 cases), interstitial and intra-alveolar oedema (in 37 cases), type 2 pneumocyte hyperplasia (in all cases), squamous metaplasia with atypia (in 21 cases), and platelet-fibrin thrombi (in 33 cases). The inflammatory infiltrate, observed in all cases, was largely composed of macrophages in the alveolar lumina (in 24 cases) and lymphocytes in the interstitium (in 31 cases). Electron microscopy revealed that viral particles were predominantly located in the pneumocytes. INTERPRETATION: The predominant pattern of lung lesions in patients with COVID-19 patients is diffuse alveolar damage, as described in patients infected with severe acute respiratory syndrome and Middle East respiratory syndrome coronaviruses. Hyaline membrane formation and pneumocyte atypical hyperplasia are frequent. Importantly, the presence of platelet-fibrin thrombi in small arterial vessels is consistent with coagulopathy, which appears to be common in patients with COVID-19 and should be one of the main targets of therapy. FUNDING: None.

MALDI imaging in Fabry nephropathy: a multicenter study.

BACKGROUND: The current study evaluates the application of histology and in situ proteomics (MALDI-MSI) in Fabry nephropathy (FN), showing investigative and classification role for this coupled approach. METHODS: A retrospective series of 14 formalin fixed paraffin embedded (FFPE) renal biopsies with diagnosis of FN and 1 biopsy from a patient bearing a galactosidase-α (GLA) genetic variant of unknown significance (GVUS, c.376A>G) have been classified for clinical characteristics. Groups were compared for histological differences (following the ISGFN scoring system). Moreover, renal biopsies from these cases have been analyzed with MALDI-MSI as previously described to find proteomic signatures among different mutations and phenotypes. RESULTS: Comparison of clinical features revealed lower mean 24 h proteinuria in females (225 mg/24 h) than in males (1477.5 mg/24 h, p = 0.006). As for clinical characteristics, females significantly differed from males only for lower arterial sclerosis, with a mean value of 0.82 vs. 1.05 (p = 0.001). Proteomic analysis demonstrated specific signatures in different subgroups of FN patients. Moreover, MALDI correctly classified cases with undetermined mutation or GVUS. CONCLUSIONS: The present study demonstrated the feasible application of MALDI-MSI in the analysis of FN FFPE renal biopsies, allowing the detection of putative signatures for phenotypic distinction and demonstrating genetic classification capabilities.

Combined Plasmatic and Tissue Approach to Membranous Nephropathy-Proposal of a Diagnostic Algorithm Including Immunogold Labelling: Changing the Paradigm of a Serum-based Approach.

Membranous nephropathy represents the most frequent cause of nephrotic syndrome in the adult, leading to end-stage renal disease in one third of all the patients. In the last years, the discovery of circulating autoantibodies against phospholipase A2 receptor 1 (PLA2R) and thrombospondin type-1 containing 7A domain (THSD7A), shed light on the pathogenesis of idiopathic forms, being responsible for 70% and 3% of all the cases, respectively. These identifications allowed the development of serological and histologic tests to detect autoantibodies and relative targets for diagnostic and prognostic purposes. Rising evidences suggest that serum titer correlates with disease activity and response to therapy. For these reasons, for patients with nephrotic syndrome, a serum-based approach has been proposed, reserving renal biopsy only in cases with doubtful/negative serology. However, the recent introduction of useful criteria for the interpretation of PLA2R/THSD7A immunohistochemistry could lead to high values of sensitivity and specificity for the in situ detection of target antigens. The present multicentric study on a series of membranous nephropathy cases with available serum/histologic correlation will show the importance of the crosstalk among the different techniques, recovering the possible role of electron microscopy in challenging situations.

Primary trichodysplasia spinulosa polyomavirus infection in a kidney transplant child displaying virus-infected decoy cells in the urine.

We report a case of primary trichodysplasia spinulosa (TS) infection in a kidney transplant child and describe for the first time the presence of degenerated TS-associated polyomavirus (TSPyV)-infected cells in a TS patient's urine that are morphologically different from BK or JC polyomavirus-infected decoy cells.

Lenvatinib-induced renal failure: two first-time case reports and review of literature.

INTRODUCTION: Lenvatinib (LEN) is a multi-kinase anti-angiogenic drug recently approved in several cancers. LEN is not easily manageable due to its complex safety profile. Proteinuria and renal failure (RF) were reported among the most frequent LEN-induced adverse events (AEs), often leading to discontinuations or dose modifications. Understanding the pathogenesis of these AEs could ameliorate the management of LEN-induced renal toxicity. Areas covered: We present two cases of LEN-induced renal failure (LIRF) with different pathogenesis. 1) LIRF with severe proteinuria in a man treated for a metastatic papillary thyroid carcinoma. Kidney biopsy showed a glomerular damage secondary to LEN, having excluded other causes of RF. 2) LIRF without proteinuria in a woman with metastatic adenoid cystic carcinoma of minor salivary gland. A tubulointerstitial nephropathy was supposed by clinical evaluation and laboratory tests. Effective management was obtained by oral steroids without interrupting LEN. Expert opinion: The case 1 presented for the first time the histological picture of LIRF with a classical glomerular damage leading to secondary proteinuria and tubular failure. Case 2 showed an alternative LIRF pattern of likely tubulointerstitial injury without proteinuria. These reports reflect two sides of the same coin, both to be considered in case of LIRF.

Clinicopathological characteristics of typical and atypical anti-glomerular basement membrane nephritis.

Anti-glomerular basement membrane (GBM) antibody disease is a rare pathological condition that mainly involves renal and/or pulmonary parenchyma. It is characterized by the presence of circulating anti-GBM antibodies accompanied by a linear deposition of immunoglobulins (Ig) detected through immunofluorescence (IF) technique and typical signs and symptoms of organ dysfunction, such as rapidly progressive glomerulonephritis (RPGN) and pulmonary hemorrhage (PH). However, recently atypical forms of anti-GBM disease have been described and the presence of overlapping diseases contributed to make its diagnosis challenging. In this review will be discussed the entire spectrum of renal anti-GBM related conditions, focusing the attention on the differences in terms of pathogenesis, diagnosis and therapy of these disparate entities.

Is imported onchocerciasis a truly rare entity? Case report and review of the literature.

BACKGROUND: Onchocerciasis is endemic in a number of tropical countries in Africa and South America, and it is occasionally diagnosed as an imported disease in non-endemic areas. METHODS: We describe the case of an African migrant with long-lasting pruritus and a cutaneous nodule who was diagnosed with onchocerciasis after nodulectomy, and review the medical literature regarding imported cases of onchocerciasis in the period 1994-2014. RESULTS: Twenty-nine cases of onchocerciasis diagnosed in migrants from endemic countries, and in expatriates and travellers from non-endemic areas were retrieved. They were predominantly males (73.3%), had a median age of 37 years (two were aged <15 years), and acquired the diseases in sub-Saharan Africa, most frequently in Cameroon (43.3%). Diagnosis of onchocercosis was proven in 73.3% of patients. The most frequent clinical manifestations in these and our own patient were pruritus (23/30, 76.7%), unilateral leg or forearm swelling (13/30, 43.3%) and rash (12/30, 40.0%), whereas only two (6.9%) complained of eye symptoms. Eosinophilia was observed in almost all of the patients (92.0%), with median counts of 2915/µL among migrants and 1960/µL among travellers/expatriates. Eighteen patients underwent a skin snip biopsy, which was positive in 10 cases (55.5%); in the other 13 patients the parasite was directly demonstrated by means of a skin or nodule biopsy (n = 5), nodulectomy (n = 5) or slit lamp examination (n = 3). Eighteen received ivermectin, alone, and seven ivermectin combined with diethylcarbamazine or doxycycline. Outcome details were available for only 14 patients, all of whom were asymptomatic after a median follow-up of 10 months (range 1-48). CONCLUSIONS: Onchocerciasis is a neglected tropical disease whose subtle and non-specific features may lead to under-diagnosis or underreporting in non-endemic areas. Physicians should consider this tropical disease when caring for migrants and travellers/expatriates with pruritus, skin lesions and eosinophilia.

Tungiasis in Italy: An imported case of Tunga penetrans and review of the literature.

Tungiasis is an animal and human parasitic disease caused by fleas of the genus Tunga (Siphonaptera, Tungidae), endemic in equatorial and subtropical regions and rarely described in European countries, where clinicians and general pathologists could be not aware of this parasitic disease. To our knowledge, only 75 cases of human tungiasis (not all described in detail) were previously reported in Italy. We described a new case in a 34-year-old Italian flight attendant who developed a granuloma-like, ulcerated nodule in the subungual region of his left 5th toe, partially detaching the nail, about 20-30 days after his return from Brazil. We performed a detailed review of the literature of the Italian cases, suggesting the use of histochemical stains (especially Trichrome stain) in order to underline parasitic details. Tourism in endemic regions and globalization may result in new cases in developed countries and previously unaffected regions, therefore pathologists should consider this parasitic disease.

Spontaneous control of HIV-1 viremia in a subject with protective HLA-B plus HLA-C alleles and HLA-C associated single nucleotide polymorphisms.

INTRODUCTION: Understanding the mechanisms by which some individuals are able to naturally control HIV-1 infection is an important goal of AIDS research. We here describe the case of an HIV-1(+) woman, CASE1, who has spontaneously controlled her viremia for the last 14 of her 20 years of infection. METHODS: CASE1 has been clinically monitored since 1993. Detailed immunological, virological and histological analyses were performed on samples obtained between 2009 and 2011. RESULTS: As for other Elite Controllers, CASE1 is characterized by low to undetectable levels of plasma HIV-1 RNA, peripheral blood mononuclear cell (PBMC) associated HIV-1 DNA and reduced in vitro susceptibility of target cells to HIV-1 infection. Furthermore, a slow rate of virus evolution was demonstrated in spite the lack of assumption of any antiretroviral agent. CASE1 failed to transmit HIV-1 to either her sexual male partner or to her child born by vaginal delivery. Normal values and ratios of T and B cells were observed, along with normal histology of the intestinal mucosa. Attempts to isolate HIV-1 from her PBMC and gut-derived cells were unsuccessful, despite expression of normal cell surface levels of CD4, CCRC5 and CXCR4. CASE1 did not produce detectable anti-HIV neutralizing antibodies in her serum or genital mucosal fluid although she displayed potent T cell responses against HIV-1 Gag and Nef. CASE1 also possessed multiple genetic polymorphisms, including HLA alleles (B*14, B*57, C*06 and C*08.02) and HLA-C single nucleotide polymorphisms (SNPs, rs9264942 C/C and rs67384697 del/del), that have been previously individually associated with spontaneous control of plasma viremia, maintenance of high CD4(+) T cell counts and delayed disease progression. CONCLUSIONS: CASE1 has controlled her HIV-1 viremia below the limit of detection in the absence of antiretroviral therapy for more than 14 years and has not shown any sign of immunologic deterioration or disease progression. Co-expression of multiple protective HLA alleles, HLA-C SNPs and strong T cell responses against HIV-1 proteins are the most likely explanation of this very benign case of spontaneous control of HIV-1 disease progression.

Cellular localization, invasion, and turnover are differently influenced by healthy and tumor-derived extracellular matrix.

The interplay between tumor cells and the microenvironment has been recognized as one of the hallmarks of cancer biology. To assess the role of extracellular matrix (ECM) in the modulation of tissue homeostasis and tumorigenesis, we developed a protocol for the purification of tissue-derived ECM using mucosae from healthy human colon, perilesional area, and colorectal carcinoma (CRC). Matched specimens were collected from the left colon of patients undergoing CRC resection surgery. ECMs were obtained from tissues that were decellularized with hypotonic solutions containing ionic and nonionic detergents, hypertonic solution, and endonuclease in the absence of denaturing agents. Mucosae-derived ECMs maintained distribution and localization of proteins and glycoproteins typical of the original tissues, and showed different three-dimensional (3D) structures among normal versus perilesional and tumor-derived stroma. The three types of ECM differentially regulated the localization and organization of seeded monocytes and cancer cells that were located and organized as in the original tissue. Specifically, healthy, perilesional, and CRC-derived ECMs sustained differentiation and polarization of cancer epithelial cells. In addition, healthy, but not perilesional and CRC-derived ECM constrained invasion of cancer cells. All three ECMs sustained turnover between cell proliferation and death up to 40 days of culture, although each ECM showed different ability in supporting cell proliferation, with tumor>perilesional>healthy-derived ECMs. Healthy-, perilesional- and CRC-derived ECM differently modulated cell homeostasis, spreading in the stroma and turnover between proliferation and death, and equally supported differentiation and polarization of cancer epithelial cells, thus highlighting the contribution of different ECMs modulating some features of tissue homeostasis and tumorigenesis. Moreover, these ECMs provide competent scaffolds useful to assess efficacy of antitumor drugs in a 3D setting that more closely recapitulates the native microenvironment. Further, ECM-based scaffolds may also be beneficial for future studies seeking prognostic and diagnostic stromal markers and targets for antineoplastic drugs.

HIV-1 infected lymphoid organs upregulate expression and release of the cleaved form of uPAR that modulates chemotaxis and virus expression.

Cell-associated receptor for urokinase plasminogen activator (uPAR) is released as both full-length soluble uPAR (suPAR) and cleaved (c-suPAR) form that maintain ability to bind to integrins and other receptors, thus triggering and modulating cell signaling responses. Concerning HIV-1 infection, plasma levels of suPAR have been correlated with the severity of disease, levels of immune activation and ineffective immune recovery also in individuals receiving combination anti-retroviral therapy (cART). However, it is unknown whether and which suPAR forms might contribute to HIV-1 induced pathogenesis and to the related state of immune activation. In this regard, lymphoid organs represent an import site of chronic immune activation and virus persistence even in individuals receiving cART. Lymphoid organs of HIV-1(+) individuals showed an enhanced number of follicular dendritic cells, macrophages and endothelial cells expressing the cell-associated uPAR in comparison to those of uninfected individuals. In order to investigate the potential role of suPAR forms in HIV-1 infection of secondary lymphoid organs, tonsil histocultures were established from HIV-1 seronegative individuals and infected ex vivo with CCR5- and CXCR4-dependent HIV-1 strains. The levels of suPAR and c-suPAR were significantly increased in HIV-infected tonsil histocultures supernatants in comparison to autologous uninfected histocultures. Supernatants from infected and uninfected cultures before and after immunodepletion of suPAR forms were incubated with the chronically infected promonocytic U1 cell line characterized by a state of proviral latency in unstimulated conditions. In the contest of HIV-conditioned supernatants we established that c-suPAR, but not suPAR, inhibited chemotaxis and induced virus expression in U1 cells. In conclusion, lymphoid organs are an important site of production and release of both suPAR and c-suPAR, this latter form being endowed with the capacity of inhibiting chemotaxis and inducing HIV-1 expression.

Imported Loa loa filariasis: three cases and a review of cases reported in non-endemic countries in the past 25 years.

OBJECTIVES: The aim of this study was to highlight the increasing chance of Western physicians encountering patients (both immigrants and expatriates/travelers) seeking help for loiasis. METHODS: We describe three cases of imported loiasis observed at two hospitals in Italy and France, and present a review of all previously published cases in the medical literature in the last 25 years (1986-2011). The search was performed using PubMed and Scopus databases using the terms "Loa loa" AND "loiasis". RESULTS: We reviewed 101 cases of imported loiasis of which 61 (60.4%) were reported from Europe and 31 (30.7%) from the USA. Seventy-five percent of infestations were acquired in three countries: Cameroon, Nigeria, and Gabon. Overall, peripheral blood microfilariae were detected in 61.4% of patients, eosinophilia in 82.1%, eye worm migration in 53.5%, and Calabar swellings in 41.6%. However, Calabar swellings and eosinophilia were more common among expatriates/travelers, whereas African immigrants were more likely to have microfilaremia. Eye worm migration was observed in a similar proportion in the two groups. Only 35 patients (including the three described here) underwent clinical follow-up for a median period of 10.5 months (range 1-84 months); clinical relapse occurred in three of these patients and persistence or reappearance of blood microfilaria in another two. CONCLUSIONS: Due to increasing travel and the migration of people from the endemic countries of West Africa to Europe and the USA, we speculate on the possible emergence of loiasis. Western physicians should be aware of the typical (eye worm migration and Calabar swellings) as well as unusual clinical presentations.