Liver infection and COVID-19: the electron microscopy proof and revision of the literature.

OBJECTIVE: COVID-19, the newly emerging infectious disease, has been associated with acute liver injury, often related to progression to severe pneumonia. The association between moderate-severe liver injury and more severe clinical course of COVID-19 has suggested that liver injury is prevalent in severe than in mild cases of COVID-19, while no difference in liver involvement has been reported between survivors and non-survivors. The spectrum of liver involvement during COVID-19 ranges from an asymptomatic elevation of liver enzymes to severe hepatitis. Only rarely, cases with acute hepatitis have been reported in the absence of respiratory symptoms. Both epithelial and biliary cells possess the angiotensin-converting enzyme-2 receptors that SARS-CoV-2 uses to be internalized. However, to our knowledge, no ultrastructural identification of the virus in liver cells has been reported to date. Here we provide evidence of SARS-CoV-2 in the liver of two patients, a 34-year-old woman and a 60-year-old man with COVID-19. PATIENTS AND METHODS: We investigated two patients with COVID-19 showing several virions within cytoplasmic vacuoles of cholangiocytes and in endothelial cells of hepatic sinusoids. In both patients, we performed histological and ultrastructural examinations by liver biopsy. After two months, both patients were free of symptoms, and the SARS-CoV-2 infection had resolved. RESULTS: Liver biopsy histological and ultrastructural examination showed liver injury and several virions within cytoplasmic vacuoles of cholangiocytes and in endothelial cells of hepatic sinusoids. CONCLUSIONS: Although most studies in COVID-19 have been focused on the lungs, recently, cholestatic liver pathology has been introduced in the spectrum of pathological changes related to COVID-19. To the best of our knowledge, those presented in this paper are the first images of hepatic SARS-CoV-2 infected liver cells. Our findings suggest a role for cholangiocytes and biliary structures in the COVID-19.

Hypoalbuminemia in COVID-19: assessing the hypothesis for underlying pulmonary capillary leakage.

BACKGROUND: Since the first observations of patients with COVID-19, significant hypoalbuminaemia was detected. Its causes have not been investigated yet. OBJECTIVE: We hypothesized that pulmonary capillary leakage affects the severity of respiratory failure, causing a shift of fluids and proteins through the epithelial-endothelial barrier. METHODS: One hundred seventy-four COVID-19 patients with respiratory symptoms, 92 admitted to the intermediate medicine ward (IMW) and 82 to the intensive care unit (ICU) at Luigi Sacco Hospital in Milan, were studied. RESULTS: Baseline characteristics at admission were considered. Proteins, interleukin 8 (IL-8) and interleukin 10 (IL-10) in bronchoalveolar lavage fluid (BALF) were analysed in 26 ICU patients. In addition, ten autopsy ultrastructural lung studies were performed in patients with COVID-19 and compared with postmortem findings in a control group (bacterial pneumonia-ARDS and H1N1-ARDS). ICU patients had lower serum albumin than IMW patients [20 (18-23) vs 28 (24-33) g L-1 , P < 0.001]. Serum albumin was lower in more compromised groups (lower PaO2 -to-FiO2 ratio and worst chest X-ray findings) and was associated with 30 days of probability of survival. Protein concentration was correlated with IL-8 and IL-10 levels in BALF. Electron microscopy examinations of eight out of ten COVID-19 lung tissues showed loosening of junctional complexes, quantitatively more pronounced than in controls, and direct viral infection of type 2 pneumocytes and endothelial cells. CONCLUSION: Hypoalbuminaemia may serve as severity marker of epithelial-endothelial damage in patients with COVID-19. There are clues that pulmonary capillary leak syndrome plays a key role in the pathogenesis of COVID-19 and might be a potential therapeutic target.

PTX3 as a potential endothelial dysfunction biomarker for severity of preeclampsia and IUGR.

Endothelial dysfunction typical of preeclampsia (PE) is the result of an excessive maternal inflammatory response to pregnancy. We investigated PTX3 in maternal, fetal and placental compartments in complicated pregnancies. Maternal blood samples were collected during the third trimester in 53 PE, 43 IUGR (intrauterine growth restriction) and 50 normal pregnancies. Fetal samples were collected from the umbilical vein in 26 PE, 23 IUGR and 26 normal pregnancies at elective cesarean section. Pattern and site of expression of PTX3 were studied by immunohistochemistry (IHC) on placenta, decidual bed and maternal peritoneum. PE and IUGR pregnancies had significantly higher maternal PTX3 levels compared to normal pregnancies, with IUGR significantly lower than PE. Maternal peritoneum expressed a significantly higher signal in the endothelium of pathological compared to normal pregnancies. The maternal increase of PTX3 correlated with the severity of disease with higher PTX3 concentrations in severe PE. Increased PTX3 levels in PE and IUGR mothers, together with IHC data represent the expression of altered endothelial function on the maternal side. IUGR fetuses had higher PTX3 values than controls and the increase was related to IUGR severity, likely reflecting the hypoxic environment. These data confirm the relevance of PTX3 in support the hypothesis that PE is a disease associated with altered maternal endothelial function. The PTX3 increase in IUGR fetuses deserves further investigation.

Glomerular lesions in HIV-positive patients: a 20-year biopsy experience from Northern Italy.

AIM: Glomerular involvement in HIV-positive patients is quite heterogeneous. In the present paper we reviewed 73 renal biopsies performed during a period of more than 20 years in a single Nephrology Unit, Milan, Northern Italy, in order to evaluate the aspects of single types of glomerular lesions (including HIV associated nephropathy-HIVAN), grouped according to histological patterns and clinical presentation. Moreover, in the group of non-HIVAN patients, the possible differences in histological characteristics from non-HIV lesions were investigated. MATERIALS AND METHODS: Renal tissues were obtained by percutaneous biopsies and were studied by light microscopy, immunofluorescence and electron microscopy. For the histological description three histological groups were identified: HIVAN, immune complex glomerulonephritis (GN) and glomerulopathies not related to immune-mediated mechanisms (so-called "various" glomerulopathies). RESULTS: HIVAN was observed in 9 cases, immune complex GNs in 40 cases (10 mesangial proliferative GN, 8 membranoproliferative GN, 5 lupus-like GN, 4 "acute" GN, 2 crescentic GN, 4 IgA nephropathy, 4 membranous GN and 3 immunotactoid GN) and "various" glomerulopathies in 24 cases (13 non-collapsing focal segmental glomerulosclerosis, 3 minimal changes, 3 end-stage renal disease, 4 diabetic nephropathy and one amyloidosis). CONCLUSIONS: Our 20-year biopsy series of HIV-related glomerular involvement confirmed the heterogeneity of lesions. In our series, the vast majority of HIV-related GN are the so-called immune complex GNs, with some peculiar aspects, as multiple site location of deposits and a frequent tendency towards sclerosis, in agreement with experimental data regarding HIV and fibrosis.

[Vacuum-assisted breast biopsy for diagnosis of non-palpable lesions: experience with 226 cases]. / Biopsia mammaria "vacuum-assisted" per la diagnosi di lesioni non palpabili: descrizione dei primi 226 casi.

Vacuum-assisted breast biopsy (VABB) is now available for non-palpable lesions. The present study describes the results obtained from 226 consecutive VABBs performed at "L. Sacco" Hospital, Milan, from November 2005 to July 2007 (198 stereotactic and 28 ultrasonographic procedures). Adequate tissue samples for histopathological evaluation were obtained in 225 cases (99.6%). The diagnoses were as follows: 9 normal tissues (4%), 97 benign (43%), 25 "probably benign" (11%), 4 "suspicious for malignancy" (2%) and 90 malignant (40%, 53 in situ and 37 infiltrating carcinoma). Of the 90 malignant cases, 38 (42.2%) underwent subsequent surgical excision in our Unit; 84.2% (32/38) had concordant histopathological findings. In conclusion, VABB is an accurate and safe technique for diagnosis of non-palpable lesions, and in experienced hands avoids unnecessary surgical procedures.

Inflammatory reaction and implantation: the new entries PTX3 and D6.

Successful embryonic implantation implies anchoring the conceptus in the maternal uterine wall, establishing a vascular supply to enable optimal growth and development of the conceptus, and promoting tolerance of fetal alloantigens encoded by paternal genes. To achieve these goals, complex molecular dialogues take place among the maternal endometrium, the conceptus, and the placenta. Several factors are involved in the fetal-maternal interaction, including hormones, growth factors, cytokines, chemokines, adhesion molecules, extracellular matrix components, and matrix-degrading enzymes. This complex cross-talk results in the induction of a local inflammatory response and a state of systemic inflammation, as revealed by leukocytosis, endothelium activation, increased activity of innate immune cells, and increased levels of inflammatory cytokines and chemokines. The enriched cytokine milieu associated to implantation is likely to control trophoblast migration and differentiation, leukocyte influx and activation, complement activation, as well as angiogenic and angiostatic processes in the implantation site. Finally, these mediators play a key role in tuning the immune responses to protect the fetus from infections as well as from maternal rejection. Here, the role of pro-inflammatory networks activated in implantation will be discussed. In particular, emphasis will be put on two new players involved in regulating inflammation at the maternal-fetal interface: the long pentraxin PTX3 and the decoy receptor for inflammatory chemokines D6.

Challenging diagnosis of an unusual solitary pulmonary nodule.

We describe the case of a 64-year-old woman with a solitary pulmonary nodule and a previous breast carcinoma whose diagnosis of histoplasmoma was established only after surgical resection and appropriate stains. It is important not to confuse these two diseases as this will prevent inappropriate medical treatment. Limited surgery is indicated for the treatment of these circumscribed lesions.

Ghrelin in human medullary thyroid carcinomas.

OBJECTIVE: Ghrelin is a novel gastrointestinal hormone involved in several metabolic functions. It has been identified previously in several normal and tumoral neuroendocrine tissues, including human medullary thyroid carcinomas (MTCs). The aim of the study was to evaluate ghrelin levels in patients with MTC and nontoxic goitre (NTG) with elevated calcitonin (CT) levels, as an additional marker of the disease. PATIENTS AND DESIGN: The study included 22 patients with MTC (four before and 18 after thyroidectomy), 12 patients with NTG with basal CT levels exceeding 10 ng/l and 15 healthy subjects matched for age, sex and body mass index (BMI). After thyroidectomy, MTC patients were considered cured when basal and pentagastrin-stimulated CT levels were < 0.2 and < 10 ng/l, respectively. A pentagastrin-induced CT peak over 50 ng/l was considered as an abnormal response while 100 ng/l was the cut-off accepted for the diagnosis of C-cell hyperplasia or tumour. Circulating ghrelin and CT levels were evaluated at baseline in patients and controls and at -10, 0, 1, 2, 5 and 15 min after pentagastrin injection (0.5 microg/kg body weight) in 12 patients with MTC and nine with NTG. Four surgically removed MTCs were tested for ghrelin expression. MEASUREMENTS: Total plasma ghrelin and CT levels were measured with a commercially available radioimmunoassay (RIA) and two-site chemiluminescence immunometric assays, respectively. In paraffin-embedded MTC samples ghrelin immunostaining was performed with a polyclonal antibody (1:1000) and the reaction visualized by an indirect immunoperoxidase system. RESULTS: Plasma ghrelin levels found in cured or not cured MTC and in NTG patients were similar to those of BMI-matched healthy controls. No correlation between ghrelin and CT levels, thyroid disease or previous thyroidectomy was observed. The administration of pentagastrin caused a 17% increase in ghrelin levels (basal ghrelin vs. peak: 162 +/- 62 pmol/l vs. 189 +/- 58 pmol/l, P < 0.05) that was particularly evident (33% increase) in patients with an abnormal CT response to the test (CT > 50 ng/l). Immunohistochemistry showed positivity for ghrelin in a small proportion of CT positive cells from the four MTCs removed. CONCLUSIONS: Patients with MTC, NTG and controls showed similar ghrelin levels, ruling out this parameter as a marker of MTC. The increase in ghrelin levels in patients with a positive CT response to pentagastrin, together with the immunopositivity for ghrelin in some MTC cells, suggests C cells as minor source of ghrelin production.

Ultrastructural study of renal involvement in two females with Anderson-Fabry disease.

Anderson-Fabry disease (AFD) is a rare X-linked lipid storage disorder due to a deficient lysosomal a-galactosidase A (a-Gal) activity. In males with the classic form of the disease the enzymatic defect leads to progressive accumulation of glycosphingolipids (GL) in different organs, mainly in the kidney, heart, and brain, causing severe multisystem failure. AFD is usually mild in heterozygous females, but severe cerebrovascular, renal, and cardiac manifestations have been rarely described. The aim of this study is to describe renal involvement of mild symptomatic female carriers by ultrastructural analysis focusing to microvascular lesions, considered to be one of the major causes of systemic disease in AFD. Resin-embedded renal biopsies from 2 sisters with isolated mild proteinuria and belonging to a family group with AFD were observed by light and electron microscopy. In spite of the mild clinical symptoms, diffuse GL storages were demonstrated in all types of glomerular cells and in interstitial endothelial cells. Moreover, platelets were frequently observed in glomerular vassels, a feature coherent with a possible role of prothrombotic state, and platelet activation, in early glomerular lesions.

Evolution of renal pathology in Fabry disease.

UNLABELLED: Fabry disease is a rare lysosomal storage disorder which results from deficient activity of the enzyme alpha-galactosidase A. The resultant deposition and progressive accumulation of glycosphingolipids in all types of body tissue leads to severe clinical manifestations involving the heart, CNS and kidney. Renal manifestations are observed relatively early in the course of the disease, and progression to end-stage renal failure is common in hemizygous males in the third to fifth decades of life. Renal biopsy specimens reveal evidence of diffuse intracytoplasmic glycosphingolipid accumulation, mainly affecting podocytes and epithelial cells of distal tubules, which are strikingly enlarged and vacuolated. On electron microscopy the deposits appear as typical osmiophilic inclusion bodies in the cytoplasm of all kinds of renal cells, and show a characteristic 'onion skin' or 'zebra' appearance. These pathological features are also evident in heterozygous females. Deposits occur before the development of renal impairment. As patients age, the disease progresses in cells throughout the kidney, and is associated with increasing glycosphingolipid accumulation. CONCLUSION: The age-related evolution of renal pathology in Fabry disease is closely correlated with progressive intracellular deposition of glycosphingolipid and ultimately leads to end-stage renal failure.

Clinical aspects of the AIDS dementia complex in relation to histopathological and immunohistochemical variables.

To correlate cerebral histopathological and immunohistochemical changes in the neuroclinical features of the AIDS dementia complex (ADC), autopsy results of 28 ADC patients were related, in a retrospective analysis, to scores on a standardised neurological examination performed at neurologic onset. From a histopathological point of view, the cases were classified as follows: 9 cases of HIV leucoencephalopathy (HIVL; diffuse myelin damage and rare microglial nodules), 7 cases of HIV encephalitis (HIVE; several microglial nodules and no myelin damage) and 12 cases of mixed HIVL and HIVE (HIVL-E). The groups differed significantly with respect to symptoms and CD4 count at neurologic onset, survival and neurological impairment. Immunohistochemically, the interstitial component (p24-positive cells scattered singly within the white matter) was significantly more prevalent in HIVL, and the micronodular component (p24-positive cells confined within microglial nodules) in HIVE. Neurological damage was worse in cases with a high prevalence of interstitial component or a low prevalence of micronodular component. HIVE, HIVL and HIVL-E are distinct clinical forms of ADC. Neurological impairment is related to white matter damage.

Molecular characterization and sequence analysis of polyomavirus strains isolated from needle biopsy specimens of kidney allograft recipients.

We retrospectively examined 29 renal allograft biopsy specimens from 42 kidney transplant recipients by means of molecular biologic techniques (nested polymerase chain reaction), immunohistochemical analysis (anti-SV40 antibody), and histologic examination to evaluate the presence of polyomaviruses (PVs), viral genotypes, genomic mutations, and their pathologic significance. PV genomes were found in six cases (21%); restriction fragment length polymorphism analysis characterized 4 as JC virus (JCV) and 2 as BK virus (BKV). The latter also were positively stained immunohistochemically and showed histologically typical intranuclear viral inclusions; JCV cases were negative. DNA sequence analysis revealed only minor changes in the 4 JCV cases (3 archetypes and 1 JCV type 3, not associated with a known pathogenic genotype) but identified 2 specific variants in the BKV isolates (AS and WW strains). Given the different histologic findings (mixed inflammatory infiltration in the AS and no inflammation in the WW strain), we speculate that different BKV strains may cause differential damage in transplanted kidneys. Finally, the negative histologic and immunohistochemical JCV results, as well as the absence of viral mutations, indicate that JCV renal infection is latent in transplant recipients.

Rantes distribution and cellular localization in the brain of HIV-infected patients.

OBJECTIVE: To study the immunochemical distribution ofRantes chemokine and its correlation with HIV-p24 expression, in brains with HIV-related lesions. MATERIAL AND METHODS: 17 HIV-positive cases of HIV-related brain lesions, 7 HIV-positive cases without cerebral HIV-related lesions (5 with opportunistic brain diseases), and 7 HIV-negative cases as controls (4 with brain lesion) were selected. RESULTS: High expression of Rantes was observed in the cases with inflammatory brain lesions (22/24 HIV-positive and 2/7 HIV-negative patients). Positivity was observed in the diffuse and nodular microglial cells and lymphocytes. In the patients with HIV-related lesions, the presence of Rantes-stained microglia did not correlate with that of HIV-p24-positive cells. Positive astrocytes were only found in the HIV-positive patients. Multinucleated giant cells were always Rantes-negative. CONCLUSIONS: Our results seem to demonstrate the role of Rantes chemokine in inducing inflammatory brain perivascular and microglial reactions both in HIV-positive and -negative patients.

Extracellular matrix globules in renal oncocytoma.

Extracellular hyaline globules resulting from abnormal accumulation of matrix components have been described in several pathological conditions, including renal tumors. We studied 16 renal oncocytomas and observed these bodies in 11 of them. In these tumors, they showed a homogeneous texture as well as roundish, smooth contours, and were easily detected in hematoxylin-eosin sections in five cases. PAS staining greatly facilitated the identification of globules in the remaining six cases, where they were fewer in number. Immunohistochemically, they appeared to be composed primarily of basement membrane material, being strongly reactive to antibodies for type IV collagen, laminin, and heparan sulphate proteoglycan. In addition, a weak immunoreactivity for type I and type III collagen, and fibronectin was observed in some cases, whereas no globule stained for tenascin. We also analyzed 89 renal cell carcinomas, and found somewhat similar bodies in 10 of them. However, they were more scanty in the latter tumors, and displayed a more irregular configuration with granular or smudged contours. We conclude that, although the mere presence of extracellular hyaline globules does not justify a distinction between renal oncocytoma and renal cell carcinoma, the detection of a large number of well-demarcated, roundish extracellular bodies with smooth contours suggests renal oncocytoma.

Beta amyloid precursor protein and patterns of HIV p24 immunohistochemistry in different brain areas of AIDS patients.

OBJECTIVES: To evaluate the correlation between immunohistochemical positive patterns (globular and filamentous structures) of beta-amyloid precursor protein (beta-APP), used as a marker of axonal damage, and the different distribution of HIV p24 antigens, in three different brain areas of AIDS patients. METHODS: Eighteen AIDS patients with HIV-related brain lesions were included in the study. Forty-nine sections from basal ganglia, frontal cortex and hippocampus were selected. After microwave oven pre-treatment, the sections were incubated with anti-HIV p24 and anti-beta-APP monoclonal antibodies; the reactions were developed with peroxidase/3,3'diaminobenzidine. The positivity was graded by semi-quantitative scores. Double immunohistochemical staining was used to evaluate the co-localization of the antigens. RESULTS: HIV p24 immunohistochemistry was positive in 44 of 49 sections (89%), with a prevalence of interstitial positive cells and positive microglial nodules in 27 and 13 sections respectively. beta-APP-positive structures were demonstrated in 23 of 44 sections (52%) with HIV-related lesions, and were absent from the five sections without viral expression. Globular and filamentous lesions were observed in 21 of 23 sections and 10 of 23 lesions respectively. Moreover, a high grade of globular type lesion was related to an elevated presence of diffuse interstitial HIV p24-positive cells in basal ganglia; double immunohistochemical reactions demonstrated the co-localization of beta-APP globules and HIV p24 antigens. CONCLUSIONS: The data obtained confirm the coexpression of beta-APP and viral antigens in particular areas of the brain with HIV-related lesions; there is a strict correlation between beta-APP globules (indicating chronic cerebral damage) and the interstitial pattern of HIV p24 immunohistochemistry.

Renal pathological changes in Fabry disease.

Fabry disease is a rare X-linked disorder, characterized by deficient activity of the lysosomal enzyme alpha-galactosidase A. This leads to systemic accumulation of the glycosphingolipid globotriaosylceramide (Gb3) in all body tissues and organs, including the kidney. Renal manifestations are less evident in female heterozygotes than in male hemizygotes, according to the Lyon hypothesis. Accumulation of Gb3 occurs mainly in the epithelial cells of Henle's loop and distal tubule, inducing early impairment in renal concentrating ability; involvement of the proximal tubule induces Fanconi syndrome. All types of glomerular cells are involved, especially podocytes, and glomerular proteinuria may occur at a young age. The evolution of renal Fabry disease is characterized by progressive deterioration of renal function to end-stage renal failure (ESRF). Ultrastructural study of kidney biopsies reveals typical bodies in the cytoplasm of all types of renal cells, characterized by concentric lamellation of clear and dark layers with a periodicity of 35-50 A. Management of progressive renal disease requires dietetic and therapeutic strategies, usually indicated in developing chronic renal failure, with dialysis and renal transplantation required for patients with ESRF. The recent development of enzyme replacement therapy, however, should make it possible to prevent or reverse the progressive renal dysfunction associated with Fabry disease.

Cryptococcus neoformans infection in a cohort of Italian AIDS patients: natural history, early prognostic parameters, and autopsy findings.

This observational cohort study of 4,160 AIDS patients hospitalised in a single institution in northern Italy between January 1985 and December 1999 was carried out in order to assess the natural history of cryptococcosis, the epidemiological trend of this opportunistic infection, the risk factors predictive of death at 10 weeks, the response to therapy, and autopsy findings. Cryptococcosis was diagnosed in 177 (4.2%) patients and was the AIDS-defining disease in 2.8% of cases. Its prevalence decreased significantly over time (from 6.4% in the period 1985-1989 to 5.7% in 1990-1993, 3.1% in 1994-1996, and 1.9% in 1997-1999, P <0.0001). Although neurologic disease was the most frequent clinical picture, a significant proportion of the patients (24.2%) presented with extraneural cryptococcosis. In a Cox multivariate analysis, high titres of cerebrospinal fluid antigen (>5000) and drug addiction were predictive of death at 10 weeks. A complete clinical and mycological response was achieved in 60.8% of the treated patients, with the highest response rate being observed in those treated with amphotericin plus flucytosine (66.6%). Cryptococcosis relapsed in 12.8% of patients on secondary prophylaxis. Autopsy findings demonstrated that cryptococcosis is a disseminated disease, but long-term antifungal treatment may be able to eradicate it in a subgroup of patients.

Anaerobic accumulation of amino acids in rice roots: role of the glutamine synthetase/glutamate synthase cycle.

Accumulation of amino acids was studied in rice roots of 3-day-old seedlings subjected for 48h to anaerobic conditions. Alanine and Gaba were the main amino acids accumulated under anoxia. Their synthesis was strongly inhibited by MSX and AZA, inhibitors of glutamine synthetase and glutamate synthase. These activities increased after 8h of anaerobic treatment and, by immunoprecipitation of 35S-labeled proteins, it was shown that glutamine synthetase and ferredoxin-dependent glutamate synthase were synthesized during the treatment. These findings indicate that the glutamine synthetase/glutamate synthase cycle play an important role in anaerobic amino acid accumulation.