Association of Digestive Symptoms and Hospitalization in Patients with SARS-CoV-2 Infection

BACKGROUND

High rates of concurrent gastrointestinal manifestations have been noted in patients with COVID- 19, however the association between these digestive manifestations and need for hospitalization has not been established.

METHODS

Following expedited approval from our Institutional Review Board, we analyzed retrospectively collected data from consecutive patients with confirmed COVID-19 based on a positive polymerase chain reaction testing at our institution from March 03, 2020 to April 7, 2020. Baseline demographic, clinical, laboratory and patient-reported symptom data were collected at presentation in the emergency room. Multivariable logistic regression analyses were performed to evaluate the association between hospitalization and presence of gastrointestinal symptoms.

RESULTS

During this study period, we identified 207 consecutive patients with confirmed COVID-19. 34.5% noted concurrent gastrointestinal symptoms; of which 90% of gastrointestinal symptoms were mild. In a multivariate regression model controlled for demographics and disease severity, an increased risk for hospitalization was noted in patients with any gastrointestinal symptom (adjusted OR 4.84 95% CI: 1.68-13.94]. Diarrhea was associated with a seven-fold higher likelihood for hospitalization (adjusted OR=7.58, 95% CI: 2.49-20.02, P <0.001) and nausea or vomiting had a four times higher odds (adjusted OR 4.39, 95% CI: 1.61-11.4, P = 0.005).

CONCLUSION

We demonstrate that a significant portion of COVID19 patients have concurrent mild gastrointestinal symptoms and that the presence of these digestive symptoms is associated with a need for hospitalization. With the current focus on streamlining triaging efforts, first responders and frontline providers should consider assessing for digestive symptoms in their initial clinical evaluation and decision-making.

The origins and functions of hepatic polyploidy

Polyploid cells contain more than two homologous sets of chromosomes. The original observations of liver polyploidy date back to the 1940s, but functional roles for polyploid cells are still unclear. Liver polyploidy may influence regeneration, stress response, and cancer, although little evidence has established direct causal links between polyploidy and these biological phenotypes. In this review, we will introduce broad concepts about polyploidy including its distribution in nature and how polyploids form in normal and pathological situations. Then we will examine recent discoveries that have begun to clarify functionality and disease relevance of liver polyploidy. Finally, we will discuss implications and future directions of research about polyploidy in the liver.

Abstract B10: The polyploid state plays a tumor-suppressive role in the liver

Most cells in the liver are polyploid, but the functional role of polyploidy is unknown. Polyploidization normally occurs through cytokinesis failure and endoreduplication around the time of weaning. To interrogate the function of polyploidy while avoiding irreversible manipulations of essential cell cycle genes, we developed multiple orthogonal mouse models to transiently and potently alter liver ploidy. Premature weaning, as well as in vivo knockdown of E2f8 or Anln, allowed us to toggle between diploid and polyploid states. While there was no impact of ploidy alterations on liver function, metabolism, or regeneration, hyperpolyploid mice suppressed and hyperdiploid mice accelerated tumorigenesis in mutagen and high fat induced models. Mechanistically, the diploid state was more susceptible to Cas9-mediated tumor suppressor loss but was similarly susceptible to MYC oncogene activation, indicating that ploidy differentially protected the liver from distinct genomic aberrations. Our work suggests that polyploidy evolved in part to prevent malignant outcomes of liver injury.

Citation Format: Shuyuan Zhang, Kejin Zhou, Xin Luo, Lin Li, Liem Nguyen, Yu Zhang, Branden Tarlow, Daniel Siegwart, Hao Zhu. The polyploid state plays a tumor-suppressive role in the liver [abstract]. In: Proceedings of the AACR Special Conference: Advances in Modeling Cancer in Mice: Technology, Biology, and Beyond; 2017 Sep 24-27; Orlando, Florida. Philadelphia (PA): AACR; Cancer Res 2018;78(10 Suppl):Abstract nr B10.

Extensive double humanization of both liver and hematopoiesis in FRGN mice

Preclinical research in animals often fails to adequately predict the outcomes observed in human patients. Chimeric animals bearing individual human tissues have been developed to provide improved models of human-specific cellular processes. Mice transplanted with human hematopoietic stem cells can be used to study human immune responses, infections of blood cells and processes of hematopoiesis. Animals with humanized livers are useful for modeling hepatotropic infections as well as drug metabolism and hepatotoxicity. However, many pathophysiologic processes involve both the liver and the hematolymphoid system. Examples include hepatitis C/HIV co-infection, immune mediated liver diseases, liver injuries with inflammation such as steatohepatitis and alcoholic liver disease.

We developed a robust protocol enabling the concurrent double-humanization of mice with mature hepatocytes and human blood. Immune-deficient, fumarylacetoacetate hydrolase (Fah^−/−), Rag2^−/− and Il2rg^−/− deficient animals on the NOD-strain background (FRGN) were simultaneously co-transplanted with adult human hepatocytes and hematopoietic stem cells after busulfan and Ad:uPA pre-conditioning. Four months after transplantation the average human liver repopulation exceeded 80% and hematopoietic chimerism also was high (40–80% in bone marrow). Importantly, human macrophages (Kupffer cells) were present in the chimeric livers.

Double-chimeric FRGN mice will serve as a new model for disease processes that involve interactions between hepatocytes and hematolymphoid cells.

The organoid-initiating cells in mouse pancreas and liver are phenotypically and functionally similar

Pancreatic Lgr5 expression has been associated with organoid-forming epithelial progenitor populations but the identity of the organoid-initiating epithelial cell subpopulation has remained elusive. Injury causes the emergence of an Lgr5(+) organoid-forming epithelial progenitor population in the adult mouse liver and pancreas. Here, we define the origin of organoid-initiating cells from mouse pancreas and liver prior to Lgr5 activation. This clonogenic population was defined as MIC1-1C3(+)/CD133(+)/CD26(-) in both tissues and the frequency of organoid initiation within this population was approximately 5% in each case. The transcriptomes of these populations overlapped extensively and showed enrichment of epithelial progenitor-associated regulatory genes such as Sox9 and FoxJ1. Surprisingly, pancreatic organoid cells also had the capacity to generate hepatocyte-like cells upon transplantation to Fah(-/-) mice, indicating a differentiation capacity similar to hepatic organoids. Although spontaneous endocrine differentiation of pancreatic progenitors was not observed in culture, adenoviral delivery of fate-specifying factors Pdx1, Neurog3 and MafA induced insulin expression without glucagon or somatostatin. Pancreatic organoid cultures therefore preserve many key attributes of progenitor cells while allowing unlimited expansion, facilitating the study of fate determination.

Factors affecting the use of a telephone-based intervention for caregivers of people with Alzheimer's disease

We investigated the usefulness of a computer-mediated interactive voice response (IVR) system integrated with voicemail to help family caregivers manage disruptive behaviours in people with Alzheimer's disease. The randomization procedure resulted in 49 caregivers being assigned to the intervention group and 51 to the control group. Using their ordinary telephone, the caregivers were linked to the four components of the IVR system: monitoring and counselling, an in-home support group, 'ask the expert', and a respite conversation. During an 18-month study, total system usage amounted to 55 min per user (SD 78, range 1-318). Half the participants used the system for at least 22 min, and 25% for at least 70 min. Participants made between one and 45 calls over the study period, averaging 11 calls (SD 12). Approximately half of the intervention group used the system regularly for two or more months. These 'adopters' were significantly older, more highly educated and reported a greater sense of management of the situation than 'non-adopters'. Adopters were much more likely than non-adopters to have been rated as highly proficient by the trainer following the technology training session. The IVR approach appealed to a subset of users. However, the overall preference was for human interaction.

A computer-mediated intervention for Alzheimer's caregivers

This article describes the background and development of an automated telecommunications system, REACH for TLC (Telephone Linked Care), for family caregivers of people with Alzheimer's disease. Caregivers press designated keys on the touch-tone keypad of their home telephones to communicate with TLC and the system speaks to caregivers using a human voice controlled by an Interactive Voice Response computer system. REACH for TLC (1) monitors the primary caregiver's stress level on a weekly basis and makes recommendations and referrals if necessary, (2) provides a voice mail caregiver support network, (3) offers access to an Alzheimer's expert panel, and (4) provides an automated distraction conversation individualized for the person with Alzheimer's disease to allow caregivers a minirespite break or to use as a tool to divert troublesome behaviors. The system is being tested in a randomized controlled feasibility study and the results will provide insight into the potential of this informatics technology to help sustain primary caregivers in their vital role.