Expression of the COVID-19 receptor ACE2 in the human conjunctiva.

SARS-CoV-2 is assumed to use angiotensin-converting enzyme 2 (ACE2) and other auxiliary proteins for cell entry. Recent studies have described conjunctival congestion in 0.8% of patients with laboratory-confirmed severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), and there has been speculation that SARS-CoV-2 can be transmitted through the conjunctiva. However, it is currently unclear whether conjunctival epithelial cells express ACE2 and its cofactors. In this study, a total of 38 conjunctival samples from 38 patients, including 12 healthy conjunctivas, 12 melanomas, seven squamous cell carcinomas, and seven papilloma samples, were analyzed using high-throughput RNA sequencing to assess messenger RNA (mRNA) expression of the SARS-CoV-2 receptor ACE2 and its cofactors including TMPRSS2, ANPEP, DPP4, and ENPEP. ACE2 protein expression was assessed in eight healthy conjunctival samples using immunohistochemistry. Our results show that the SARS-CoV-2 receptor ACE2 is not substantially expressed in conjunctival samples on the mRNA (median: 0.0 transcripts per million [TPM], min: 0.0 TPM, max: 1.7 TPM) and protein levels. Similar results were obtained for the transcription of other auxiliary molecules. In conclusion, this study finds no evidence for a significant expression of ACE2 and its auxiliary mediators for cell entry in conjunctival samples, making conjunctival infection with SARS-CoV-2 via these mediators unlikely.

Risk of Virus Contamination Through Surgical Smoke During Minimally Invasive Surgery: A Systematic Review of the Literature on a Neglected Issue Revived in the COVID-19 Pandemic Era.

CONTEXT: The coronavirus disease 2019 (COVID-19) pandemic raised concerns about the safety of laparoscopy due to the risk of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) diffusion in surgical smoke. Although no case of SARS-CoV-2 contagion related to surgical smoke has been reported, several international surgical societies recommended caution or even discouraged the use of a laparoscopic approach. OBJECTIVE: To evaluate the risk of virus spread due to surgical smoke during surgical procedures. EVIDENCE ACQUISITION: We searched PubMed and Scopus for eligible studies, including clinical and preclinical studies assessing the presence of any virus in the surgical smoke from any surgical procedure or experimental model. EVIDENCE SYNTHESIS: We identified 24 studies. No study was found investigating SARS-CoV-2 or any other coronavirus. About other viruses, hepatitis B virus was identified in the surgical smoke collected during different laparoscopic surgeries (colorectal resections, gastrectomies, and hepatic wedge resections). Other clinical studies suggested a consistent risk of transmission for human papillomavirus (HPV) in the surgical treatments of HPV-related disease (mainly genital warts, laryngeal papillomas, or cutaneous lesions). Preclinical studies showed conflicting results, but HPV was shown to have a high risk of transmission. CONCLUSIONS: Although all the available data come from different viruses, considering that the SARS-CoV-2 virus has been shown in blood and stools, the theoretical risk of virus diffusion through surgical smoke cannot be excluded. Specific clinical studies are needed to understand the effective presence of the virus in the surgical smoke of different surgical procedures and its concentration. Meanwhile, adoption of all the required protective strategies, including preoperative patient nasopharyngeal swab for COVID-19, seems mandatory. PATIENT SUMMARY: In this systematic review, we looked at the risk of virus spread from surgical smoke exposure during surgery. Although no study was found investigating severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) or any other coronavirus, we found that the theoretical risk of virus diffusion through surgical smoke cannot be excluded.