PD-L1 Overexpression in the Lungs of Subjects Who Died from COVID-19: Are We on the Way to Understanding the Immune System Exhaustion Induced by SARS-CoV-2?

Knowledge of the pathogenic mechanisms of severe acute respiratory syndrome-associated coronavirus 2 (SARS-CoV-2) is certainly a priority for the scientific community. Two main elements are involved in the biology of the most severe forms of coronavirus disease 2019 (COVID-19): the direct cytopathic effect of the virus against the host tissues, and a dysfunction of the immune system, characterized by the exhaustion of T lymphocytes. The exhaustion of T cells in COVID-19 is poorly understand, but some data could suggest a possible role of PD-1/PD-L1 axis. The aim of this study was to evaluate the possible role of PD-L1 expression in the pulmonary tissue in subjects affected by COVID-19. The presence of SARS-CoV-2 in the pulmonary tissue, and its exact location, was indagated by in situ hybridization; the expression of PD-L1 and CD8 in the same tissue was indagated by immunohistochemistry. Overall, PD-L1 resulted diffusely expressed in 70% of the cases, and an intense expression was observed in 43.5% of cases. Diffuse and intense presence of SARS-CoV-2 by in situ hybridization significantly correlated with an intense PD-L1 expression, and with expression of PD-L1 by pneumocytes. PD-L1 is overexpressed in the pulmonary tissue of subjects died from COVID-19, and mainly in subjects with a high viral load. These data suggest a possible role of PD-L1 in the immune system exhaustion at the basis of the severe forms of the disease.

Variable levels of spike and ORF1ab RNA in post-mortem lung samples of SARS-CoV-2-positive subjects: comparison between ISH and RT-PCR.

Post-mortem examination plays a pivotal role in understanding the pathobiology of the SARS-CoV-2; thus, the optimization of virus detection on the post-mortem formalin-fixed paraffin-embedded (FFPE) tissue is needed. Different techniques are available for the identification of the SARS-CoV-2, including reverse transcription polymerase chain reaction (RT-PCR), immunohistochemistry (IHC), in situ hybridization (ISH), and electron microscopy. The main goal of this study is to compare ISH versus RT-PCR to detect SARS-CoV-2 on post-mortem lung samples of positive deceased subjects. A total of 27 samples were analyzed by RT-PCR targeting different viral RNA sequences of SARS-CoV-2, including envelope (E), nucleocapsid (N), spike (S), and open reading frame (ORF1ab) genes and ISH targeting S and Orf1ab. All 27 cases showed the N gene amplification, 22 out of 27 the E gene amplification, 26 out of 27 the S gene amplification, and only 6 the ORF1ab gene amplification. The S ISH was positive only in 12 out of 26 cases positive by RT-PCR. The S ISH positive cases with strong and diffuse staining showed a correlation with low values of the number of the amplification cycles by S RT-PCR suggesting that ISH is a sensitive assay mainly in cases carrying high levels of S RNA. In conclusion, our findings demonstrated that ISH assay has lower sensitivity to detect SARS-CoV-2 in FFPE compared to RT-PCR; however, it is able to localize the virus in the cellular context since it preserves the morphology.

Genome-wide microRNA expression profiling in placentas from pregnant women exposed to BPA.

BACKGROUND: Bisphenol A (BPA) is an environmental compounds is known to possess endocrine disruption potentials. Bisphenol A has epigenetic effects as deregulated expression of microRNAs; such epigenetic marks can induce up/down alterations in gene expression that may persist throughout a lifetime. Bisphenol A (BPA) exposure has been documented in pregnant women, but consequences for development of offspring after BPA exposure during pregnancy are not yet widely studied. Therefore, the aim of this study was to gain a comprehensive understanding of microRNAs changes in the placenta transcriptome from pregnant women subjected to therapeutic abortion for fetal malformation and correlate the impact of gestational exposure to BPA on these developmental changes. METHODS: We performed a comparative analysis of genome wide miRNA expression in placentas from pregnant women exposed to BPA using microarray technology to identify miRNAs which were aberrantly expressed in placentas from malformed fetuses. The expression changes of differential expressed miRNAs in the samples used for microarray were confirmed by qPCR . Beside, we applied various bioinformatics tools to predict the target genes of the identified miR-146a and explore their biological function and downstream pathways. RESULTS: We found that miR-146a was significant overexpressed and correlated significantly with BPA accumulation in the placenta from pregnant women living in a polluted area and undergoing therapeutic abortion due to fetal malformations. Beside, we applied various bioinformatics tools to predict the target genes of miR-146a and explore their biological function and downstream pathways. CONCLUSIONS: For the first time, we found, in humans, that miR-146a was significant over-expressed and correlated significantly with BPA accumulation in the placenta. Our results lead to the suggestion that miRNAs could be potential biomarkers to clarify the mechanisms of environmental diseases.

Pericarditis Epistenocardica or Dressler Syndrome? An Autopsy Case.

Postinfarction pericarditis can be classified as "early," referred to as pericarditis epistenocardica, or "delayed," referred to as Dressler syndrome. The incidence of postinfarction pericarditis has decreased to <5% since the introduction of reperfusion therapies and limitation of infarct size. We report on a 57-year-old man who suffered sudden cardiac death as a result of acute myocardial infarction. Autopsy revealed an area of previous infarction and fibrinous pericarditis related to the previous infarction, leading to a diagnosis of Dressler syndrome.

Validation of an extension of the international non-invasive criteria for the diagnosis of hepatocellular carcinoma to the characterization of macroscopic portal vein thrombosis.

BACKGROUND AND AIM: We aimed to validate the non-invasive criteria for the characterization of portal vein thrombosis (PVT) in patients with cirrhosis and hepatocellular carcinoma (HCC). In a prospective study, we examined the impact of arterial hypervascularity, as established by the European Association for the Study of the Liver and the American Association for the Study of Liver Diseases recommendations for the non-invasive diagnosis of HCC, as a criterion for characterizing macroscopic PVT (EASL/AASLD extension criteria). METHODS: A total of 96 cases of PVT detected using ultrasonography in patients with cirrhosis and HCC were included in the study. When coincidental arterial hypervascularity was detected by contrast perfusional ultrasonography and helical computed tomography, the thrombus was considered malignant according to our EASL/AASLD extension criteria. In all cases, an ultrasound-guided biopsy examination of the thrombus was performed. RESULTS: Coincidental hypervascularity was found in 54 of 96 nodules (56.2%), and all were malignant upon biopsy (100% positive predictive value). Twenty-four (25%) had negative results with both techniques (non-vascular thrombus). Biopsies showed HCC in five non-vascular thrombi (5.3% of all thrombi) and in 13 of 18 thrombi with a hypervascularity result from only one technique. CONCLUSIONS: The EASL/AASLD extension criteria for non-invasive diagnosis of malignant thrombosis were satisfied in 75.2% of malignant thrombi; thus, a biopsy is frequently required in this setting. However, in the presence of coincidental hypervascularity of a thrombus with both techniques, a biopsy is not required (absolute positive predictive value for malignancy). Relying on imaging techniques in thrombi could miss the diagnosis of malignant portal invasion in up to 24.9% of cases.

[Prognostic and curative value of sentinel node in breast cancer. A 377 patients experience]. / Valore prognostico e curativo del linfonodo sentinella nel trattamento chirurgico del cancro della mammella. Analisi di 377 pazienti.

Sentinel node is defined as the first lymphnode receiving limphatic drain from the breast. Several studies show a very low recurrence rate to axillary and locoregional nodes in sentinel node negative patients who did not undergo axillary dissection. Our study aims to verify if complete axillary dissection could be replaced by sentinel node biopsy (SNB) in the staging and treatment of breast cancer. From January 2005 to December 2008, 377 patients (mean age 57.63) underwent SNB in the General Surgery unit of "San Giuseppe Moscati" Hospital in Avellino (Italy). All the patients underwent SNB with local anesthesia. Histologic studies were performed using GIVOM protocol (Veneto Breast cancer interdisciplinary group). Sixty five patients (17.2%) underwent a radical mastectomy with SNB and 312 (82.6%) patients underwent a quadrantectomy with SNB. Of this last group, 178 (47.2%) underwent a superior quadrant excision with SNB, 77 (20.4%) an inferior quadrant excision with SNB and 57 (15.1%) a central quadrant excision with SNB. Ductal carcinoma represented 57.3% of the tumous detected, lobular carcinoma was diagnosed in 16.4% of the cases, intraductal microinvasive carcinoma in 10.3%, ductal carcinoma in situ in 5.8% while the other histotypes were diagnosed in 10% of the tumours. All SNB+ patients (34.5%) underwent a radical axillary dissection in general anesthesia. Sixty nine (53%) patients were diagnosed with axillary node metastasis, after axillary dissection Micrometastasis resulted in 19.6% of the excised patients. The prevalence of axillary node metastasis was 26.4% (581/2198), while the incidence was 34.5% (130/377). The first axillary lymphnodes level was metastasized in 65.8% patients who had undergone an axillary dissection, level I and II in 268% and all the levels in 7.4%. Only one case (0.4%) of nodal metastatic recurrence has been diagnosed in patients who had undergone SNB alone, after a mean follow-up of 28.5 month. Apart from showing a very high diagnostic and staging accuracy, the high level of SN detection associated with a high predictive rate underline a lower complications rate if compared to complete nodal dissection.

Oxidative stress and steatosis are cofactors of liver injury in primary biliary cirrhosis.

BACKGROUND: Factors responsible for the progression of primary biliary cirrhosis (PBC) are still poorly understood. In the present study, we investigated the associations between the stage of PBC and the immune reaction triggered by oxidative stress; the presence of obesity, steatosis,steatohepatitis; and other toxic, metabolic, or steatogenic factors. METHODS: We studied clinical, laboratory, and histological data for 274 untreated patients with serum antimitochondrial antibody (AMA)-positive PBC. Circulating IgG against human serum albumin adducted with malondialdeyde, the major product of lipid peroxidation, was measured in these patients and in a group of 98 sex-, age and body mass index (BMI)-matched controls. RESULTS: Steatosis was present in 40.5% of all patients. Steatohepatitis was present in 14.9% of all patients. There was a significant association between the frequencies of steatosis and steatohepatitis and the worsening of PBC. Circulating IgG against lipid peroxidation products was significantly higher in the PBC patients than in the controls. Titers of lipid peroxidation-related antibodies were significantly increased in patients with steatosis and inpatients at more advanced stages. Bivariate analysis revealed a significant association between indirect evidence of oxidative stress, steatosis, steatohepatitis, age, BMI, frequency of diabetes, alcohol intake, iron grade after Perl's stain, and PBC stage. Logistic regression analysis confirmed that the titers of antibodies against lipid peroxidation products (odds ratio 4.5, p< .001, 95% confidence interval 3.9­14.4), the presence of steatosis (odds ratio 4.1, 95% confidence interval 2.5­15.4, p< .001), higher BMI (odds ratio 3.9, p< .021, 95%confidence interval 1.4­9.5), and alcohol intake (males ≥ 30 g/day, females ≥ 20 g/day, odds ratio 4.5,95% confidence interval 1.3­19.8, p< .029) were independently associated with more advanced stages of the disease. CONCLUSIONS: The immune reactions triggered by oxidative stress, steatosis, obesity, and alcohol intake are independent predictors of PBC stage progression.