Evidence of a Sjogrens disease-like phenotype following COVID-19

ObjectivesSjogrens Disease (SjD) is a chronic and systemic autoimmune disease characterized by lymphocytic infiltration and the development of dry eyes and dry mouth resulting from the secretory dysfunction of the exocrine glands. SARS-CoV-2 may trigger the development or progression of autoimmune diseases, as evidenced by increased autoantibodies in patients and the presentation of cardinal symptoms of SjD. The objective of the study was to determine whether SARS-CoV-2 induces the signature clinical symptoms of SjD. MethodsThe ACE2-transgenic mice were infected with SARS-CoV-2. SJD profiling was conducted. COVID-19 patients sera were examined for autoantibodies. Clinical evaluations of convalescent COVID-19 subjects, including minor salivary gland (MSG) biopsies, were collected. Lastly, monoclonal antibodies generated from single B cells of patients were interrogated for ACE2/spike inhibition and nuclear antigens. ResultsMice infected with the virus showed a decreased saliva flow rate, elevated antinuclear antibodies (ANAs) with anti-SSB/La, and lymphocyte infiltration in the lacrimal and salivary glands. Sera of COVID-19 patients showed an increase in ANA, anti-SSA/Ro52, and anti-SSB/La. The male patients showed elevated levels of anti-SSA/Ro52 compared to female patients, and female patients had more diverse ANA patterns. Minor salivary gland biopsies of convalescent COVID-19 subjects showed focal lymphocytic infiltrates in four of six subjects, and 2 of 6 subjects had focus scores >2. Lastly, we found monoclonal antibodies produced in recovered patients can both block ACE2/spike interaction and recognize nuclear antigens. ConclusionOverall, our study shows a direct association between SARS-CoV-2 and SjD. Hallmark features of SjD salivary glands were histologically indistinguishable from convalescent COVID-19 subjects. The results potentially implicate that SARS-CoV-2 could be an environmental trigger for SjD. Key MessagesWhat is already known about this subject? O_LISAR-CoV-2 has a tropism for the salivary glands. However, whether the virus can induce clinical phenotypes of Sjogrens disease is unknown. C_LI What does this study add? O_LIMice infected with SAR-CoV-2 showed loss of secretory function, elevated autoantibodies, and lymphocyte infiltration in glands. C_LIO_LICOVID-19 patients showed an increase in autoantibodies. Monoclonal antibodies produced in recovered patients can block ACE2/spike interaction and recognize nuclear antigens. C_LIO_LIMinor salivary gland biopsies of some convalescent subjects showed focal lymphocytic infiltrates with focus scores. C_LI How might this impact on clinical practice or future developments? O_LIOur data provide strong evidence for the role of SARS-CoV-2 in inducing Sjogrens disease-like phenotypes. C_LIO_LIOur work has implications for how patients will be diagnosed and treated effectively. C_LI

Sensitive extraction-free SARS-CoV-2 RNA virus detection using a novel RNA preparation method

Current conventional detection of SARS-CoV-2 involves collection of a patient sample with a nasopharyngeal swab, storage of the swab during transport in a viral transport medium, extraction of RNA, and quantitative reverse transcription PCR (RT-qPCR). We developed a simplified and novel preparation method using a Chelex resin that obviates RNA extraction during viral testing. Direct detection RT-qPCR and digital-droplet PCR was compared to the current conventional method with RNA extraction for simulated samples and patient specimens. The heat-treatment in the presence of Chelex markedly improved detection sensitivity as compared to heat alone, and lack of RNA extraction shortens the overall diagnostic workflow. Furthermore, the initial sample heating step inactivates SARS-CoV-2 infectivity, thus improving workflow safety. This fast RNA preparation and detection method is versatile for a variety of samples, safe for testing personnel, and suitable for standard clinical collection and testing on high throughput platforms.

Integrated Single-Cell Atlases Reveal an Oral SARS-CoV-2 Infection and Transmission Axis

Despite signs of infection, the involvement of the oral cavity in COVID-19 is poorly understood. To address this, single-cell RNA sequencing data-sets were integrated from human minor salivary glands and gingiva to identify 11 epithelial, 7 mesenchymal, and 15 immune cell clusters. Analysis of SARS-CoV-2 viral entry factor expression showed enrichment in epithelia including the ducts and acini of the salivary glands and the suprabasal cells of the mucosae. COVID-19 autopsy tissues confirmed in vivo SARS-CoV-2 infection in the salivary glands and mucosa. Saliva from SARS-CoV-2-infected individuals harbored epithelial cells exhibiting ACE2 expression and SARS-CoV-2 RNA. Matched nasopharyngeal and saliva samples found distinct viral shedding dynamics and viral burden in saliva correlated with COVID-19 symptoms including taste loss. Upon recovery, this cohort exhibited salivary antibodies against SARS-CoV-2 proteins. Collectively, the oral cavity represents a robust site for COVID-19 infection and implicates saliva in viral transmission.