SARS-CoV-2 detection in formalin-fixed paraffin-embedded tissue specimens from surgical resection of tongue squamous cell carcinoma

Detection of SARS-CoV-2 RNA by In Situ Hybridization in Lung-Cancer Cells Metastatic to Brain and in Adjacent Brain Parenchyma

The mechanisms by which severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) may spread to the human brain are poorly understood, and the infection of cancer cells in the brain by SARS-CoV-2 in Coronavirus disease 2019 (COVID-19) patients has been the subject of only one previous case report. Here, we report the detection of SARS-CoV-2 RNA by in situ hybridization in lung-cancer cells metastatic to the brain and adjacent brain parenchyma in a 63-year-old male patient with COVID-19. These findings suggest that metastatic tumors may transport the virus from other parts of the body to the brain or may break down the blood-brain barrier to allow for the virus to spread to the brain. These findings confirm and extend previous observations that cancer cells in the brain can become infected by SARS-CoV-2 in patients with COVID-19 and raise the possibility that SARS-CoV-2 can have a direct effect on cancer growth and outcome.

Detection of SARS-CoV-2 and Its Related Factors on the Mucosal Epithelium of the Tongue

SARS-CoV-2 infects a variety of tissues, including the oral cavity. However, there are few reports examining the association of SARS-CoV-2 with tongue mucosal tissues with sticky tongue debris. This study investigated the presence of SARS-CoV-2 and its associated molecules by dissecting tongue tissue from autopsy specimens of 23 patients who died of COVID-19-related illness (pneumonia). Immunohistochemical staining, electron microscopy, and PCR analysis were performed on the tongue tissue specimens. The mucosal epithelium of the tongue formed a very thick keratinized with well-developed filiform papillae in all cases. ACE2 and TMPRSS2 were consistently co-expressed in all samples in the epithelium. The S-protein was strongly expressed in basal cells and the epithelial surface. S-protein-positive viral particles were detected in the tongue's stratified squamous epithelium via an immunoelectron microscope. Based on PCR amplification of the N1 and N2 regions, the SARS-CoV-2 gene was detected on the tongue epithelium, tongue submucosa, and in tongue debris. This suggests that tongue debris, including the squamous epithelial tissue, could be a source of SARS-CoV-2 in saliva. Furthermore, removing tongue debris may decrease the amount of SARS-CoV-2 in the oral cavity.

Pathogenic Mechanism and Multi-omics Analysis of Oral Manifestations in COVID-19

Coronavirus disease 2019 (COVID-19) is a respiratory infectious disease that seriously threatens human life. The clinical manifestations of severe COVID-19 include acute respiratory distress syndrome and multiple organ failure. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causal agent of COVID-19, spreads through contaminated droplets. SARS-CoV-2 particles have been detected in the saliva of COVID-19 patients, implying that the virus can infect and damage the oral cavity. The oral manifestations of COVID-19 include xerostomia and gustatory dysfunction. Numerous studies showed that the four structural proteins of SARS-CoV-2 are its potential pathogenic factors, especially the S protein, which binds to human ACE2 receptors facilitating the entry of the virus into the host cells. Usually, upon entry into the host cell, a pathogen triggers the host’s immune response. However, a mount of multi-omics and immunological analyses revealed that COVID-19 is caused by immune dysregulation. A decrease in the number and phenotypes of immune cells, IFN-1 production and excessive release of certain cytokines have also been reported. In conclusion, this review summarizes the oral manifestations of COVID-19 and multi-omics analysis of SARS-CoV-2 infection.

Morphological and Immunopathological Aspects of Lingual Tissues in COVID-19

COVID-19, a recently emerged disease caused by SARS-CoV-2 infection, can present with different degrees of severity and a large variety of signs and symptoms. The oral manifestations of COVID-19 often involve the tongue, with loss of taste being one of the most common symptoms of the disease. This study aimed to detect SARS-CoV-2 RNA and assess possible morphological and immunopathological alterations in the lingual tissue of patients who died with a history of SARS-CoV-2 infection. Sixteen cadavers from 8 SARS-CoV-2 positive (COVID-19+) and 8 negative (COVID-19−) subjects provided 16 tongues, that were biopsied. Samples underwent molecular analysis through Real-Time RT-PCR for the detection of SARS-CoV-2 RNA. Lingual papillae were harvested and processed for histological analysis and for immunohistochemical evaluation for ACE2, IFN-γ and factor VIII. Real-Time RT-PCR revealed the presence of SARS-CoV-2 RNA in filiform, foliate, and circumvallate papillae in 6 out of 8 COVID-19+ subjects while all COVID-19− samples resulted negative. Histology showed a severe inflammation of COVID-19+ papillae with destruction of the taste buds. ACE2 and IFN-γ resulted downregulated in COVID-19+ and no differences were evidenced for factor VIII between the two groups. The virus was detectable in most COVID-19+ tongues. An inflammatory damage to the lingual papillae, putatively mediated by ACE2 and IFN-γ in tongues from COVID-19+ cadavers, was observed. Further investigations are needed to confirm these findings and deepen the association between taste disorders and inflammation in SARS-CoV-2 infection.

Absolute quantitation of individual SARS-CoV-2 RNA molecules provides a new paradigm for infection dynamics and variant differences

Despite an unprecedented global research effort on SARS-CoV-2, early replication events remain poorly understood. Given the clinical importance of emergent viral variants with increased transmission, there is an urgent need to understand the early stages of viral replication and transcription. We used single-molecule fluorescence in situ hybridisation (smFISH) to quantify positive sense RNA genomes with 95% detection efficiency, while simultaneously visualising negative sense genomes, subgenomic RNAs, and viral proteins. Our absolute quantification of viral RNAs and replication factories revealed that SARS-CoV-2 genomic RNA is long-lived after entry, suggesting that it avoids degradation by cellular nucleases. Moreover, we observed that SARS-CoV-2 replication is highly variable between cells, with only a small cell population displaying high burden of viral RNA. Unexpectedly, the B.1.1.7 variant, first identified in the UK, exhibits significantly slower replication kinetics than the Victoria strain, suggesting a novel mechanism contributing to its higher transmissibility with important clinical implications.

COVID-19: Multiorgan Dissemination of SARS-CoV-2 Is Driven by Pulmonary Factors

Multi-organ failure is one of the common causes of fatal outcome in COVID-19 patients. However, the pathogenetic association of the SARS-CoV-2 viral load (VL) level with fatal dysfunctions of the lungs, liver, kidneys, heart, spleen and brain, as well as with the risk of death in COVID-19 patients remains poorly understood. SARS-CoV-2 VL in the lungs, heart, liver, kidneys, brain, spleen and lymph nodes have been measured by RT qPCR using the following formula: N^SARS-CoV-2/N^{ABL1 ×} 100. Dissemination of SARS-CoV-2 in 30.5% of cases was mono-organ, and in 63.9% of cases, it was multi-organ. The average SARS-CoV-2 VL in the exudative phase of diffuse alveolar damage (DAD) was 60 times higher than in the proliferative phase. The SARS-CoV-2 VL in the lungs ranged from 0 to 250,281 copies. The "pulmonary factors" of SARS-CoV-2 multi-organ dissemination are the high level of SARS-CoV-2 VL (≥4909) and the exudative phase of DAD. The frequency of SARS-CoV-2 dissemination to lymph nodes was 86.9%, heart-56.5%, spleen-52.2%, liver-47.8%, kidney-26%, and brain-13%. We found no link between the SARS-CoV-2 VL level in the liver, kidneys, and heart and the serum level of CPK, LDH, ALP, ALT, AST and Cr of COVID-19 patients. Isolated detection of SARS-CoV-2 RNA in the myocardium of COVID-19 patients who died from heart failure is possible. The pathogenesis of COVID-19-associated multi-organ failure requires further research in a larger cohort of patients.

COVID-19 manifestation in the oral cavity - a narrative literature review

COVID-19 is an infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a recently discovered coronavirus, which in 2020 led to a global pandemic. Clinical manifestations of COVID-19 are very diverse and symptoms range from mild to severe. Correlated symptoms might also manifest in the oral cavity, which is a potential pathway for viral infection, and therefore might be a potential pathway for SARS-CoV-2. In recent research among patients with SARS-CoV-2 infection, taste and olfactory disorders, dry mouth, drones and inflammation of mouth, bitter taste in mouth, difficulty in swallowing and burning sensations have been reported. There have been cases of oral mucosal lesions in patients diagnosed with COVID-19 disease. Some correlations between periodontitis and severity of COVID-19 disease have also been observed. Oral mucosa, due to occurrence of ACE2 receptors, is highly susceptible to SARS-CoV-2 infection. The occurrence of changes on oral mucosa should increase the alertness of dental practitioners. However, knowledge in this area is still limited and in the field of oral manifestations of COVID-19 more research and patient observations are required.

The "oral" history of COVID-19: Primary infection, salivary transmission, and post-acute implications

Severe acute respiratorysyndrome coronavirus 2 (SARS-CoV-2), the causative agent of COVID-19, has led to more than 3.25 million recorded deaths worldwide as of May 2021. COVID-19 is known to be clinically heterogeneous, and whether the reported oral signs and symptoms in COVID-19 are related to the direct infection of oral tissues has remained unknown. Here, we review and summarize the evidence for the primary infection of the glands, oral mucosae, and saliva by SARS-CoV-2. Not only were the entry factors for SARS-CoV-2 found in all oral tissues, but these were also sites of SARS-CoV-2 infection and replication. Furthermore, saliva from asymptomatic individuals contained free virus and SARS-CoV-2-infected oral epithelial cells, both of which were found to transmit the virus. Collectively, these studies support an active role of the oral cavity in the spread and transmission of SARS-CoV-2 infection. In addition to maintaining the appropriate use of personal protective equipment and regimens to limit microbial spread via aerosol or droplet generation, the dental community will also be involved in co-managing COVID-19 "long haulers"-now termed Post-Acute COVID-19 Syndrome. Consequently, we propose that, as SARS-CoV-2 continues to spread and as new clinical challenges related to COVID-19 are documented, oral symptoms should be included in diagnostic and prognostic classifications as well as plans for multidisciplinary care.

Oral manifestations of COVID-19 patients: An online survey of the Egyptian population

OBJECTIVES

This pilot survey aims to study the oral manifestations associated with COVID-19 infection and report the prevalence of oral signs and symptoms in COVID-19 patients.

MATERIALS AND METHODS

From May 15 to June 10, 2020, we used an online questionnaire containing the oral manifestations that are expected to be associated with the COVID-19 infection. Adults in our survey who have been diagnosed with COVID-19 positive were confirmed with reverse transcriptase PCR (RT-PCR), and isolated in various hospitals in Cairo, Egypt.

RESULTS

This pilot study included 58 (53.4% males and 46.6% females) COVID-19 patients ages 18-46 years, and 13 (22.4%) were healthcare workers. Our results showed that 67.2% of the patients had at least one manifestation related to the oral cavity and salivary glands, and 32.8% (n = 19) did not have any symptoms associated with the oral cavity. The highest prevalence symptoms were dry mouth 39.7% (n = 23), gustatory dysfunction as 34.5% (n = 20) loss of salt sensation, 29.3% (n = 17) loss of sweet sensation, and 25.9% (n = 15) altered food taste, while the least prevalent symptoms were tongue redness 8.8% (n = 5), and gingival bleeding 7% (n = 4). The most frequently associated symptoms were loss of salt and sweetness, as reported by 27.6% of the participants. However, there was no significant association between the incidence of oral symptoms and demographic data (age, gender, or job) of the patients (p > 0.05).

CONCLUSIONS

Based on limited data, COVID-19 significantly impacts the oral cavity and salivary glands, as salivary gland-related symptoms and taste disorders are highly prevalent in COVID-19 patients.

Multisystemic Cellular Tropism of SARS-CoV-2 in Autopsies of COVID-19 Patients

Multiorgan tropism of SARS-CoV-2 has previously been shown for several major organs. We have comprehensively analyzed 25 different formalin-fixed paraffin-embedded (FFPE) tissues/organs from autopsies of fatal COVID-19 cases (n = 8), using histopathological assessment, detection of SARS-CoV-2 RNA using polymerase chain reaction and RNA in situ hybridization, viral protein using immunohistochemistry, and virus particles using transmission electron microscopy. SARS-CoV-2 RNA was mainly localized in epithelial cells across all organs. Next to lung, trachea, kidney, heart, or liver, viral RNA was also found in tonsils, salivary glands, oropharynx, thyroid, adrenal gland, testicles, prostate, ovaries, small bowel, lymph nodes, skin and skeletal muscle. Viral RNA was predominantly found in cells expressing ACE2, TMPRSS2, or both. The SARS-CoV-2 replicating RNA was also detected in these organs. Immunohistochemistry and electron microscopy were not suitable for reliable and specific SARS-CoV-2 detection in autopsies. These findings were validated using in situ hybridization on external COVID-19 autopsy samples (n = 9). Apart from the lung, correlation of viral detection and histopathological assessment did not reveal any specific alterations that could be attributed to SARS-CoV-2. In summary, SARS-CoV-2 and its replication could be observed across all organ systems, which co-localizes with ACE2 and TMPRSS2 mainly in epithelial but also in mesenchymal and endothelial cells. Apart from the respiratory tract, no specific (histo-)morphologic alterations could be assigned to the SARS-CoV-2 infection.

SARS-CoV-2 RNA screening in routine pathology specimens

Virus detection methods are important to cope with the SARS-CoV-2 pandemics. Apart from the lung, SARS-CoV-2 was detected in multiple organs in severe cases. Less is known on organ tropism in patients developing mild or no symptoms, and some of such patients might be missed in symptom-indicated swab testing. Here, we tested and validated several approaches and selected the most reliable RT-PCR protocol for the detection of SARS-CoV-2 RNA in patients' routine diagnostic formalin-fixed and paraffin-embedded (FFPE) specimens available in pathology, to assess (i) organ tropism in samples from COVID-19-positive patients, (ii) unrecognized cases in selected tissues from negative or not-tested patients during a pandemic peak, and (iii) retrospectively, pre-pandemic lung samples. We identified SARS-CoV-2 RNA in seven samples from confirmed COVID-19 patients, in two gastric biopsies, one small bowel and one colon resection, one lung biopsy, one pleural resection and one pleural effusion specimen, while all other specimens were negative. In the pandemic peak cohort, we identified one previously unrecognized COVID-19 case in tonsillectomy samples. All pre-pandemic lung samples were negative. In conclusion, SARS-CoV-2 RNA detection in FFPE pathology specimens can potentially improve surveillance of COVID-19, allow retrospective studies, and advance our understanding of SARS-CoV-2 organ tropism and effects.

Characterisation of cardiac pathology in 23 autopsies of lethal COVID-19

While coronavirus disease 2019 (COVID-19) primarily affects the respiratory tract, pathophysiological changes of the cardiovascular system remain to be elucidated. We performed a retrospective cardiopathological analysis of the heart and vasculature from 23 autopsies of COVID-19 patients, comparing the findings with control tissue. Myocardium from autopsies of COVID-19 patients was categorised into severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) positive (n = 14) or negative (n = 9) based on the presence of viral RNA as determined by reverse transcriptase polymerase chain reaction (RT-PCR). Control tissue was selected from autopsies without COVID-19 (n = 10) with similar clinical sequelae. Histological characteristics were scored by ordinal and/or categorical grading. Five RT-PCR-positive cases underwent in situ hybridisation (ISH) for SARS-CoV-2. Patients with lethal COVID-19 infection were mostly male (78%) and had a high incidence of hypertension (91%), coronary artery disease (61%), and diabetes mellitus (48%). Patients with positive myocardial RT-PCR died earlier after hospital admission (5 versus 12 days, p < 0.001) than patients with negative RT-PCR. An increased severity of fibrin deposition, capillary dilatation, and microhaemorrhage was observed in RT-PCR-positive myocardium than in negatives and controls, with a positive correlation amongst these factors All cases with increased cardioinflammatory infiltrate, without myocyte necrosis (n = 4) or with myocarditis (n = 1), were RT-PCR negative. ISH revealed positivity of viral RNA in interstitial cells. Myocardial capillary dilatation, fibrin deposition, and microhaemorrhage may be the histomorphological correlate of COVID-19-associated coagulopathy. Increased cardioinflammation including one case of myocarditis was only detected in RT-PCR-negative hearts with significantly longer hospitalisation time. This may imply a secondary immunological response warranting further characterisation.

SARS-CoV-2 Infection and Significance of Oral Health Management in the Era of "the New Normal with COVID-19"

More than a year ago, the coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), was declared a pandemic by the World Health Organization, with the world approaching its fourth wave. During this period, vaccines were developed in a much shorter period than thought possible, with the initiation of the pertinent vaccination. However, oral cavities have come under renewed scrutiny worldwide because saliva, a mixture of salivary secretions, pharyngeal secretions, and gingival crevicular fluid, have not only been shown to contain infective viral loads, mediating the route of SARS-CoV-2 transmission via droplet, aerosol, or contagion, but also used as a sample for viral RNA testing with a usefulness comparable to the nasopharyngeal swab. The oral cavity is an important portal for ingress of SARS-CoV-2, being an entryway to the bronchi, alveoli, and rest of the lower respiratory tract, causing inflammation by viral infection. Moreover, angiotensin-converting enzyme 2, a host receptor for SARS-CoV-2, coupled with proteases responsible for viral entry have been found to be expressed on the tongue and other oral mucosae, suggesting that the oral cavity is the site of virus replication and propagation. Furthermore, there is a possibility that the aspiration of oral bacteria (such as periodontal pathogens) along with saliva into the lower respiratory tract may be a complicating factor for COVID-19 because chronic obstructive pulmonary disease and diabetes are known COVID-19 comorbidities with a greater risk of disease aggravation and higher death rate. These comorbidities have a strong connection to chronic periodontitis and periodontal pathogens, and an oral health management is an effective measure to prevent these comorbidities. In addition, oral bacteria, particularly periodontal pathogens, could be proinflammatory stimulants to respiratory epithelia upon its exposure to aspirated bacteria. Therefore, it may be expected that oral health management not only prevents comorbidities involved in aggravating COVID-19 but also has an effect against COVID-19 progression. This review discusses the significance of oral health management in SARS-CoV-2 infection in the era of “the new normal with COVID-19” and COVID-19 prevention with reference to the hypothetical mechanisms that the authors and the other researchers have proposed.

Changes in thyroid fine needle aspiration practice during the COVID-19 pandemic

Purpose

To investigate the diagnostic accuracy of a different sample preparation protocol for fine needle aspiration cytology (FNAC) of thyroid nodules established during the COVID‐19 pandemic.

Methods

From April 2020, conventional smears during FNAC were ceased according to World Health Organization recommendations due to the increased infection risk for operators, and a new protocol using only liquid‐based cytology (LBC) was adopted. FNACs performed between April and July 2020 (COVID‐19 group) were retrospectively compared with those from December 2019 through March 2020 (Pre‐COVID‐19 group). The distribution of diagnoses based on SIAPEC‐IAP categories and the concordance between cytological and histological results were compared using the chi‐squared test.

Results

Categories based on FNAC for 90 and 82 thyroid nodules in the Pre‐COVID‐19 and COVID‐19 groups showed no significant difference in distribution (P = .081), with the following respective cases (and percentages): TIR1, 7 (8%) and 8 (10%); TIR1C, 0 (0%) and 6 (7%); TIR2, 59 (66%) and

55 (67%); TIR3A, 8 (9%) and 5 (6%); TIR3B, 1 (1%) and 2 (3%); TIR4, 5 (6%) and 1 (1%); and TIR5, 10 (12%) and 5 (7%). Among patients with potentially malignant lesions, surgery was performed for 12/16 (75%) nodules in the Pre‐COVID‐19 and 7/8 (88%) nodules in the COVID‐19 groups, with no significant differences between cytological and histological diagnoses (P = .931).

Conclusion

The new LBC‐only protocol provided similar diagnostic accuracy in comparison with conventional smears, and can be effectively applied during a viral pandemic improving operator safety.

Human Type II Taste Cells Express Angiotensin-Converting Enzyme 2 and Are Infected by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2)

Chemosensory changes are well-reported symptoms of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. The virus targets cells for entry by binding of its spike protein to cell-surface angiotensin-converting enzyme 2 (ACE2). It is not known whether ACE2 is expressed on taste receptor cells (TRCs), or whether TRCs are infected directly. in situ hybridization probe and an antibody specific to ACE2 indicated presence of ACE2 on a subpopulation of TRCs (namely, type II cells in taste buds in taste papillae). Fungiform papillae of a SARS-CoV-2⁺ patient exhibiting symptoms of coronavirus disease 2019 (COVID-19), including taste changes, were biopsied. Presence of replicating SARS-CoV-2 in type II cells was verified by in situ hybridization. Therefore, taste type II cells provide a potential portal for viral entry that predicts vulnerabilities to SARS-CoV-2 in the oral cavity. The continuity and cell turnover of a patient's fungiform papillae taste stem cell layer were disrupted during infection and had not completely recovered 6 weeks after symptom onset. Another patient experiencing post-COVID-19 taste disturbances also had disrupted stem cells. These results demonstrate the possibility that novel and sudden taste changes, frequently reported in COVID-19, may be the result of direct infection of taste papillae by SARS-CoV-2. This may result in impaired taste receptor stem cell activity and suggest that further work is needed to understand the acute and postacute dynamics of viral kinetics in the human taste bud.

Human Taste Cells Express ACE2: a Portal for SARS-CoV-2 Infection

Loss and changes in taste and smell are well-reported symptoms of SARS-CoV-2 infection. The virus targets cells for entry by high affinity binding of its spike protein to cell-surface angiotensin-converting enzyme- 2 (ACE2). It was not known whether ACE2 is expressed on taste receptor cells (TRCs) nor if TRCs are infected directly. Using an in-situ hybridization (ISH) probe and an antibody specific to ACE2, it seems evident that ACE2 is present on a subpopulation of specialized TRCs, namely, PLCβ2 positive, Type II cells in taste buds in taste papillae. Fungiform papillae (FP) of a SARS-CoV-2+ patient exhibiting symptoms of COVID-19, including taste changes, were biopsied. Based on ISH, replicating SARS-CoV-2 was present in Type II cells of this patient. Therefore, taste Type II cells provide a portal for viral entry that predicts vulnerabilities to SARS-CoV-2 in the oral cavity. The continuity and cell turnover of the FP taste stem cell layer of the patient were disrupted during infection and had not fully recovered 6 weeks post symptom onset. Another patient suffering post-COVID-19 taste disturbances also had disrupted stem cells. These results indicate that a COVID-19 patient who experienced taste changes had replicating virus in their taste buds and that SARS-CoV-2 infection results in deficient stem cell turnover needed for differentiation into TRCs.

The challenges and risk of laboratory handling on a histology specimen during COVID-19 pandemic

The Coronavirus Disease 2019 (COVID-19) pandemic has taken the world into turmoil by surprise. The rapid spreading of this virus has led to an exponential increase in the number of cases. It has created a public health disaster, causing a collapse of the health system in every part of the world. Many sectors in the health area are affected, including histopathology services. The challenges and risk of viral transmission can come from various aspects and levels. For COVID-19 tests, there are even cases of no direct contact with the specimens; the specimens received infection from individuals of unknown status. The fixatives used for histopathology specimens are believed to be inactivated viruses, which can be an inactivate coronavirus. Even so, precautions have to be put in place to prevent the spread of infection to laboratory personnel, especially to those handling underfixed and fresh frozen cytology samples. Precautions must also be taken when dealing with histopathology services, by wearing full personal protective equipment and by executing other standard safety measures. The purpose of this review is to highlight the challenges faced in managing histopathology services in our centre during the COVID-19 pandemic.

Emergency Lung Transplantation after COVID-19: Immunopathological Insights on Two Affected Patients

We herein characterize the immunopathological features of two Italian COVID-19 patients who underwent bilateral lung transplantation (bLTx). Removed lungs underwent histopathological evaluation. Gene expression profiling (GEP) for immune-related signatures was performed on lung specimens and SARS-CoV-2-stimulated peripheral blood mononuclear cells (PBMCs). Cytokine levels were measured on lungs, bronchoalveolar lavage fluids and in culture supernatants. Pathological assessment showed extensive lung damage with the pattern of proliferative to fibrotic phases, with diffuse alveolar damage mimicking usual interstitial pneumonia (UIP). Lungs’ GEP revealed overexpression of pathogen recognition receptors, effector cytokines and chemokines, immune activation receptors and of the inflammasome components. Multiplex cytokine analysis confirmed a proinflammatory state, with high levels of monocyte/macrophage chemotactic and activating factors and of IL-6 and TNF-α. A similar profile was observed in SARS-CoV-2-stimulated PBMCs collected 7 days after transplant. The pattern of tissue damage observed in the lungs suggests that this may represent the output of protracted disease, resembling a diffuse UIP-like picture. The molecular immune profiling supports the paradigm of a persistent proinflammatory state and sustained humoral immunity, conditions that are maintained despite the iatrogenic immunosuppression.

Acute Invasive Rhino-Orbital Mucormycosis in a Patient With COVID-19-Associated Acute Respiratory Distress Syndrome

Acute invasive fungal rhinosinusitis is a rare, although highly morbid, infection primarily affecting immunosuppressed individuals. The same population is at particularly high risk of complications and mortality in the setting of SARS-CoV-2 infection and coronavirus disease 2019 (COVID-19)-related acute respiratory distress syndrome. The authors present a case of acute invasive fungal rhino-orbital mucormycosis in a patient with COVID-19 and discuss the prevalence, diagnosis, and treatment of fungal coinfections in COVID-19. Prompt recognition, initiation of therapy, and consideration of the challenges of rapidly evolving COVID-19 therapy guidelines are important for improving patient survival.

Brain donation in the era of COVID 19: challenges to the harvest in the face of a pandemic

We have experienced numerous new challenges during the process of brain harvesting in the period of COVID-19. Although brain harvests have continued successfully during this time period, the numerous uncertainties and challenges described in this paper have nearly derailed the process several times. While the interface of the medical profession with patients in the context of a pandemic has been well-documented on several fronts, and particularly for those health care workers on the front lines, we are not aware of any documentary accounts of the challenges facing research and tissue donation programs. With this paper, we contribute an additional perspective and describe the lessons we have learned in addressing these novel issues.

Retrospective Post-mortem SARS-CoV-2 RT-PCR of Autopsies with COVID-19-Suggestive Pathology Supports the Absence of Lethal Community Spread in Basel, Switzerland, before February 2020

INTRODUCTION

Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has rapidly spread around the world. While the first case was recorded in Hubei in December 2019, the extent of early community spread in Central Europe before this period is unknown. A high proportion of asymptomatic cases and undocumented infections, high transmissibility, and phylogenetic genomic diversity have engendered the controversial possibility of early international community spread of SARS-CoV-2 before its emergence in China.

METHODS

To assess the early presence of lethal COVID-19 in Switzerland, we retrospectively performed an analysis of deaths at University Hospital Basel between October 2019 and February 2020 (n = 310), comparing the incidence of clinical causes of death with March 2020 (n = 72), the month during which the first lethal COVID-19 cases in Basel were reported. Trends of COVID-19-suggestive sequelae, such as bronchopneumonia with organization, acute respiratory distress syndrome (ARDS), or pulmonary embolisms (PE) were evaluated. In cases where autopsy was performed (n = 71), analogous analyses were conducted on the cause of death and pulmonary histological findings. Eight cases with a COVID-19-suggestive clinical history and histopathology between October 2019 and February 2020, and 3 cases before October 2019, were selected for SARS-CoV-2 RT-PCR.

RESULTS

A statistically significant rise in pulmonary causes of death was observed in March 2020 (p = 0.03), consistent with the reported emergence of lethal COVID-19 in Switzerland. A rise in lethal bronchopneumonia was observed between December 2019 and January 2020, which was likely seasonal. The incidence of lethal ARDS and PE was uniformly low between October 2019 and February 2020. All autopsy cases analyzed by means of SARS-CoV-2 RT-PCR yielded negative results.

CONCLUSION

Our data suggest the absence of early lethal community spread of COVID-19 in Basel before its initial reported emergence in Switzerland in March 2020.

Angioedema, ACE inhibitor and COVID-19

SARS-CoV-2, the virus responsible for COVID-19, binds to the ACE2 receptors. ACE2 is thought to counterbalance ACE in the renin-angiotensin system. While presently it is advised that patients should continue to use ACE inhibitors or angiotensin receptor blockers, questions still remain as to whether adverse effects are potentiated by the virus. Here, we report a case of a 57-year-old man, unknowingly with COVID-19, who presented to the emergency department with tongue swelling, shortness of breath and difficulty in speaking following 4 months taking benazepril, an ACE inhibitor. Finally, we also describe possible pathways that exist for SARS-CoV-2 to interact with the mechanism behind angioedema.

Oral mucosal lesions in patients with SARS-CoV-2 infection. Report of four cases. Are they a true sign of COVID-19 disease?

BACKGROUND

Vesiculobullous and macular lesions in the oral mucosa have been reported in patients positive for SARS-CoV-2 infection. Nonetheless, the significance and physiopathology of oral manifestations have not been clearly established in the clinical progression or outcome of the infection.

AIM

To describe the clinico-pathological oral mucosal lesions in four patients with confirmed SARS-CoV-2 infection.

METHODS AND RESULTS

Four patients with COVID-19 disease and confirmed by polymerase chain reaction (PCR) presented angina bullosa hemorragica-like lesion, vascular disorder, and nonspecific stomatitis, one patient with histological analysis demonstrated perivascular reactive lymphocitic infliltrate, focal capillary thrombosis, and hemorrhage. According to the discrimination of other local and systemic conditions and the synchronous onset of oral and systemic symptoms, the diagnosis of oral lesions probably associated with COVID-19 was established.

CONCLUSION

Infection with SARS-CoV-2 may result in oral manifestations with various clinical presentations, which presumably support the hypothesis of thrombi formation and vasculitis; nevertheless, these findings need more evidence and a long-term follow up of patients to accurately establish the significance of the oral mucosa affection in the COVID-19 disease.

Pulmonary pathology and COVID-19: lessons from autopsy. The experience of European Pulmonary Pathologists

Since its initial recognition in December 2019, Coronavirus disease 19 (COVID-19) has quickly spread to a pandemic infectious disease. The causative agent has been recognized as a novel coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), primarily affecting the respiratory tract. To date, no vaccines are available nor any specific treatment. To limit the number of infections, strict directives have been issued by governments that have been translated into equally rigorous guidelines notably for post-mortem examinations by international and national scientific societies. The recommendations for biosafety control required during specimen collection and handling have strongly limited the practice of autopsies of the COVID-19 patients to a few adequate laboratories. A full pathological examination has always been considered an important tool to better understand the pathophysiology of diseases, especially when the knowledge of an emerging disorder is limited and the impact on the healthcare system is significant. The first evidence of diffuse alveolar damage in the context of an acute respiratory distress syndrome has now been joined by the latest findings that report a more complex scenario in COVID-19, including a vascular involvement and a wide spectrum of associated pathologies. Ancillary tools such as electron microscopy and molecular biology used on autoptic tissue samples from autopsy are also significantly contributing to confirm and/or identify new aspects useful for a deeper knowledge of the pathogenetic mechanisms. This article will review and summarize the pathological findings described in COVID-19 until now, chiefly focusing on the respiratory tract, highlighting the importance of autopsy towards a better knowledge of this disease.

A review on histotechnology practices in COVID-19 pathology investigations

COVID-19 disease in humans, caused by the novel SARS-CoV-2 virus, was first reported in the city of Wuhan, China in December 2019. This disease has quickly developed into a global pandemic, resulting in over 350,000 deaths worldwide and over 5 million confirmed infections in a matter of 6 months. Although the genome of this novel viral RNA was sequenced quickly and testing kits were manufactured to assist in combatting COVID-19, the diagnosis and treatment will remain relatively unsuccessful until the pathology of this disease is fully understood. Histotechnology plays an important role in understanding the pathology of many diseases, including COVID-19. The first postmortem biopsy of a COVID-19 patient was collected on 27 January 2020, and the pathology finding was published in mid-February 2020. Since then, more studies have been published in scientific literatures as the global outbreak continues. This mini-review summarizes the published articles in which histotechnology aspects were utilized with the intent to understand the pathology of COVID-19. In addition, it is anticipated there will be more molecular and immunohistochemical studies to further understand the mechanism of the disease in the near future.