Faculty Bibliography

Background: In addition to respiratory distress, GI symptoms have been reported in COVID-19 patients at various stages of the disease. Among the GI symptoms that have been reported, diarrhea, nausea, vomiting, abdominal pain and GI bleeding were often seen. Age and comorbid conditions such as obesity, HTN, DM and/or CAD have been considered as risk factors for COVID-19 patients for severe disease. GI manifestations in COVID-19 patients appeared to act as a sign for a serious condition. The virus has been identified in the stool and in rectal swabs of some infected patients, even after a negative nasopharyngeal test. There is a lack of reports on pathological alterations of the GI tract in COVID-19 infected patients.
Design(s): 16 PCR confirmed COVID-19 patients (11 males and 5 females) were included in the study. Biopsy or resection specimens were taken from the esophagus (4), stomach (6), small intestine (5), appendix (3), colon (5) and gallbladder (3). Clinical information including demographics, comorbidities, GI symptoms, related laboratory tests were collected. Histopathologic evaluation was performed and correlated with clinical properties.
Result(s): The age of the patients ranged from 10 to 84 years old, with an average of 47 years. Eight (50%) patients had at least one comorbid condition, two patients (12.5%) had prior history of cancer, and six patients had no significant medical history. Abdominal pain and GI bleeding were the most common presenting symptoms. Histologically, acute and chronic inflammation was seen in 14 of 16, and 15 of 16 cases, respectively. Eight cases showed severe acute inflammation with ulceration. The mucosal changes included nonspecific reactive change, hypermucinous, atrophic/ischemic changes, and necrosis, were indiscriminately noticed in these cases. Four cases showed intraepithelial lymphocytosis. Viral like inclusions were found in four cases. Microthrombi were identified in 5 cases with an average patient age of 60 years. Notably, microthrombi were seen in about 5 out of 8 (62%) patients with comorbidities. The patients with microthrombi had a higher D dimer test value than those without thrombus. Three patients died shortly after operation, and two of them showed microthrombi in the tissue specimens.
Conclusion(s): Acute and chronic inflammation were indiscriminately seen in these cases. Microthrombi were dominantly found in aging patients with comorbidities, suggesting microthrombi in the GI tract may be a histologic indication for severe COVID-19 patients with GI symptoms

Bodies have continuous reticular networks, comprising collagens, elastin, glycosaminoglycans, and other extracellular matrix components, through all tissues and organs. Fibrous coverings of nerves and blood vessels create structural continuity beyond organ boundaries. We recently validated fluid flow through human fibrous tissues, though whether these interstitial spaces are continuous through the body or discontinuous, confined within individual organs, remains unclear. Here we show evidence for continuity of interstitial spaces using two approaches. Non-biological particles (tattoo pigment, colloidal silver) were tracked within colon and skin interstitial spaces and into adjacent fascia. Hyaluronic acid, a macromolecular component of interstitial spaces, was also visualized. Both techniques demonstrate interstitial continuity within and between organs including within perineurium and vascular adventitia traversing organs and the spaces between them. We suggest that there is a body-wide network of fluid-filled interstitial spaces that has significant implications for molecular signaling, cell trafficking, and the spread of malignant and infectious disease.

PT150 is a clinical-stage molecule, taken orally, with a strong safety profile having completed Phase 1 and Phase 2 clinical trials for its original use as an antidepressant. It has an active IND for COVID-19. Antiviral activities have been found for PT150 and other members of its class in a variety of virus families; thus, it was now tested against SARS-CoV-2 in human bronchial epithelial lining cells and showed effective 90% inhibitory antiviral concentration (EC90) of 5.55 µM. PT150 is a member of an extended platform of novel glucocorticoid receptor (GR) and androgen receptor (AR) modulating molecules. In vivo, their predominant net effect is one of systemic glucocorticoid antagonism, but they also show direct downregulation of AR and minor GR agonism at the cellular level. We hypothesize that anti-SARS-CoV-2 activity depends in part on this AR downregulation through diminished TMPRSS2 expression and modulation of ACE2 activity. Given that hypercortisolemia is now suggested to be a significant co-factor for COVID-19 progression, we also postulate an additive role for its potent immunomodulatory effects through systemic antagonism of cortisol.

Multiplexed immunohistochemical techniques give insight into contextual cellular relationships by offering the ability to collect cell-specific data with spatial information from formalin-fixed, paraffin-embedded tissue sections. We established an automated sequential elution-stripping multiplex immunohistochemical assay to address two controversial scientific questions in the field of hepatopathology: 1) whether epithelial-to-mesenchymal transition or mesenchymal-to-epithelial transition occurs during liver injury and repair of a chronic liver disease and 2) if there is a stromal:epithelial relationship along the canals of Hering that would support the concept of this biliary structure being a stem/progenitor cell niche. Our 4-plex assay includes both epithelial and mesenchymal clinical immunohistochemical markers and was performed on clinical human liver specimens in patients with primary biliary cholangitis. The assay demonstrated that in each specimen, co-expression of epithelial and mesenchymal markers was observed in extraportal cholangiocytes. In regard to possible mesenchymal components in a stem cell niche, 82.3% ± 5.5% of extraportal cholangiocytes were intimately associated with a vimentin-positive cell. Co-expression of epithelial and mesenchymal markers by extraportal cholangiocytes is evidence for epithelial to mesenchymal transition in primary biliary cholangitis. Vimentin-positive stromal cells are frequently juxtaposed to extraportal cholangiocytes, supporting an epithelial:mesenchymal relationship within the hepatobiliary stem cell niche. Our automated sequential elution-stripping multiplex immunohistochemical assay is a cost-effective multiplexing technique that can be readily applied to a small series of clinical pathology samples in order to answer scientific questions involving cell:cell relationships and cellular antibody expression.

Background: As hepatocellular carcinoma (HCC) develops from premalignant lesions (low and high grade dysplastic nodules; LGDN and HGDN), there is a corresponding accumulation of molecular alterations, some of which have been well described. However, the molecular features of lesions comprising the hepatocellular dysplasia-carcinoma sequence as they relate to different etiologies have not yet been explored. Herein, we characterize the molecular landscape of such lesions in cirrhotic explants with alcohol-related liver disease (ALD) and chronic hepatitis C (CHC).
Design(s): Tissue was assessed from 27 liver explants (14 CHC, 13 ALD) including 10 LGDNs (5 CHC, 5 ALD), 8 HGDNs (3 CHC, 5 ALD), 10 HCCs arising from HGDNs (5 CHC, 5 ALD), and 10 small HCCs defined as HCC < 2 cm (5 CHC, 5 ALD), as well as non-lesional cirrhotic parenchyma and matched normal non-liver tissue (e.g. porta hepatis structures). DNA was extracted from FFPE tissue for next generation sequencing (NGS) using a customized NGS580 panel targeting all exonic and select intronic areas in 580 cancer related genes. Data was analyzed using customized bioinformatics pipelines with an R package.
Result(s): TERT promoter HS C228T mutations were identified in 6 of 10 (60%) CHC related HCCs and only 1 of 9 (11%) alcohol related HCC (Figure 1). There was a significant association between TERT promoter HS C228T mutations and CHC related HCCs (p<0.02). In contrast, ALD related lesions showed deleterious events affecting tumor suppressor genes (NF1, BRCA1; CDKN2C) and histone methylation/chromatin remodeling genes (KMT2A; KMT2C; ASXL1; RAD21), which were found in 6 of 13 ALD related lesions (46.2% [3 of 5 small HCCs, 2 of 4 HGDNs, and 1 of 4 HCCs arising in HGDNs]). These events only occurred in 3 of 14 (21.4%) CHC related lesions (Figures 1 and 2). Within the CHC group, 1 HCC arising in HGDN showed copy number gains (CNG) in MARK4, ERCC2, FGFR4 and FLT4 and two HGDNs showed CNGs in NOTCH1 and TERT, respectively. No differences in the tumor mutational burden (TMB) were noted between CHC related and ALD related lesions, nor across the DN-HCC sequence. Non-lesional liver and LGDNs did not show recurrent mutations pertaining to a specific pathway. (Figure presented)
Conclusion(s): Our findings suggest that the pathways of hepatocarcinogenesis are distinct in ALD and CHC. While upregulation of telomerase activity (TA) and cancer cell immortalization play a pivotal role in CHC related HCC, defective chromatin remodeling appears to contribute to tumorigenesis in ALD related HCC