Physicians need to consider that gastrointestinal (GI) symptoms, such as nausea, vomiting, and diarrhea could be early signs of COVID-19 infection, especially in those GI patients who also present with upper respiratory complaints. Meanwhile, patients with digestive diseases should closely monitor the news and stay in touch with their doctors if they experience new or unusual GI symptoms.

These were among the insights summarized recently by clinical researchers at the Icahn School of Medicine at Mount in New York City. They also provided renewed guidance to physicians for those patients who have inflammatory bowel disease (IBD) and are being treated with immunosuppressive agents. Research suggests, they said, these patients may be considered at high risk for COVID-19, which is caused by the SARS-CoV-2 virus.

“This is a rapidly evolving area with new information emerging on a daily basis,” said Ryan Ungaro, MD, MS, Assistant Professor of Medicine (Gastroenterology). “We strongly urge our patients to closely monitor the news and to stay in touch with their doctors if they experience new or unusual GI symptoms.”

For physicians seeing a patient with predominant GI symptoms, and some respiratory symptoms, “COVID-19 should be part of a differential diagnosis,” he added.

Dr. Ungaro and world-renowned physician-scientist Jean-Frederic Colombel, MD, published an overview of COVID-19 research findings for the gastroenterology community to help them address their patients’ questions and concerns. It was published on March 17, 2020, in Clinical Gastroenterology and Hepatology, a journal of the American Gastroenterological Association. Dr. Colombel is Director of the Susan and Leonard Feinstein Inflammatory Bowel Disease Clinical Center at Mount Sinai, and Professor of Medicine (Gastroenterology). Also contributing were Mount Sinai’s Timothy Sullivan, MD, Assistant Professor of Medicine (Infectious Diseases), and Gopi Patel, MD, Associate Professor of Medicine (Infectious Diseases).

In their overview, the researchers recounted what has been learned to date:

— The SARS-CoV-2 virus shares 79.5 percent of the genetic sequence of SARS, a respiratory illness caused by a coronavirus that appeared in 2002.

— In that outbreak, diarrhea was reported in up to 25 percent of SARS patients.

— The reported frequency of diarrhea among COVID-19 patients has varied from 2 percent to 33 percent, however, it was one of the prominent symptoms reported in the first U.S. COVID-19 case.

— SARS-CoV-2 has been detected in the stool of COVID-19 patients.

— Common laboratory findings described in COVID-19 patients also include liver function test abnormalities.

“While COVID-19 appears to primarily spread through respiratory droplets and secretions,” the authors wrote, “the gastrointestinal tract may be another potential route of infection.” With this possibility, they reinforced the importance that gastroenterologists use personal protective equipment during endoscopy.

They acknowledged that there are no data currently about the impact of immunosuppressive agents. “At the current time, we should not advise IBD patients, or others on immunosuppressive agents, such as those with autoimmune hepatitis, for example, to hold or stop medications,” they wrote, as the risk of disease flare is still a larger concern at this time. They further suggested that physicians advise their patients on immunosuppression to follow the Centers for Disease Control and Prevention (CDC) guidelines for at-risk populations.

They additionally highlighted new evidence on the cell entry receptor ACE2. “Interestingly,” they wrote, “the cell entry receptor ACE2 appears to mediate entry of SARS-CoV-2,” a similar phenomenon observed with SARS, “and has been demonstrated to be highly expressed in small intestinal enterocytes,” the intestinal absorptive cells that line the inner surface of the small and large intestines. ACE2 is important in regulating nutrient absorption, in particular basic amino acids such as tryptophan, and its disruption may lead to diarrhea.

Mount Sinai is actively studying ACE2 expression in intestinal tissue, said Dr. Ungaro, referring to the work of Saurabh Mehandru, MD, Associate Professor of Medicine (Gastroenterology). “We are particularly interested in determining if the ACE2 inhibitor is differentially expressed in patients with inflammatory conditions of the GI tract to better understand this patient population’s susceptibility to SARS-CoV-2.”

Additionally, Mount Sinai, with collaborators from the University of North Carolina, has started a web-based registry for physicians to report any IBD patients who have a confirmed case of COVID-19. The goal is to better understand the impact of immunosuppressive medications and other risk factors to best guide clinical decisions, he said. Regular updates on reported cases are available at https://covidibd.org/.

Dr. Ungaro reports he served as an advisory board member or consultant for Eli Lilly, Janssen, Pfizer, and Takeda and has research grants from AbbVie, Boehringer Ingelheim, and Pfizer.

Image from Florian Krammer lab. The main target on the surface of most coronaviruses is the spike protein or S. This is a model of the virus and a visualization of a crystal structure of the spike of SARS-CoV-2.

The Mount Sinai Health System this week plans to initiate a procedure known as plasmapheresis, where the antibodies from patients who have recovered from COVID-19 will be transferred into critically ill patients with the disease, with the expectation that the antibodies will neutralize it.

The process of using antibody-rich plasma from COVID-19 patients to help others was used successfully in China, according to a state-owned organization, which reported that some patients improved within 24 hours, with reduced inflammation and viral loads, and better oxygen levels in the blood.

Mount Sinai is collaborating with the New York Blood Center and the New York State Department of Health’s Wadsworth Center laboratory in Albany, with guidance from the U.S. Food and Drug Administration, and expects to begin implementing the treatment later this week.

“We are hoping to identify patients who can provide the antibodies,” says Dennis S. Charney, MD, Anne and Joel Ehrenkranz Dean of the Icahn School of Medicine at Mount Sinai, and President for Academic Affairs, Mount Sinai Health System. “We are at the front lines in fighting this pandemic and making discoveries that will help our patients.”

Late last week, researchers at the Icahn School of Medicine, in collaboration with scientists in Australia and Finland, were among the first to create an antibody test that detects the disease’s antibodies in a person’s blood. Development of the enzyme-linked immunosorbent assay (ELISA) was led by Florian Krammer, PhD, Professor of Microbiology, in collaboration with Viviana A. Simon, MD, PhD, Professor of Microbiology and Medicine (Infectious Diseases). Dr. Krammer, a renowned influenza researcher, recently made this so-called recipe available to other laboratories around the world so they can replicate it during the pandemic. In January, his lab was quickly retooled to begin studying COVID-19.

In addition to its widespread use in plasmapheresis, the antibody test will provide experts with an accurate infection rate so they can track the trajectory of the disease. The test will help identify health care workers who are already immune to the disease, who can work directly with infectious patients, and it can also help scientists understand how the human immune system reacts to the virus.

The new assay uses recombinant or manufactured antigens from the spike protein on the surface of the SARS-CoV-2 virus. That protein helps the virus enter cells, and it is a key target in the immune reaction against the virus, as the body creates antibodies that recognize the protein and seek to destroy the virus. The researchers also isolated the short piece of the spike protein called the receptor-binding domain (RBD), which the virus uses to attach to cells it tries to invade. The scientists then used cell lines to produce large quantities of the altered spike proteins and RBDs.

According to Dr. Krammer and his co-authors, the assay is “sensitive and specific,” and allows for the screening and identification of COVID-19 in human plasma/serum as soon as three days after the onset of symptoms. The antibodies were derived from three patients who had the disease. The study’s control participants—who did not have COVID-19 but had other viruses, including the common cold—ranged in age from 20 to 70.

Dr. Krammer says his preliminary findings also show that humans have no natural immunity to the SARS-CoV-2 virus, which would help explain why it spreads so quickly. But once the antibody sets in humans do become protected. He also says that at this early stage in the research, there is no evidence that people can lose their immunity and become re-infected.

Patients in China with COVID-19 showed distinct patterns in their lungs that became more defined within a few of days of disease onset, according to two cardiothoracic radiologists at the Mount Sinai Health System, who were the first in the nation to examine the CT scans of Chinese patients with the coronavirus.

The radiologists, Michael S. Chung, MD, and Adam Bernheim, MD, from the Icahn School of Medicine at Mount Sinai, say the distinct markings of these 121 patients offer objective evidence that could help doctors diagnose COVID-19 within minutes. The CT scans would support the health care community’s work in determining who has the disease and its ability to quickly isolate and treat patients. The test swabs being used to confirm the disease in patients can take up to 12 hours to process.

In a study that appeared in the February issue of Radiology, Drs. Chung and Bernheim described the disease characteristics of patients at four hospitals located in four different provinces in China. The patients were between the ages of 18 and 80, and their cases ranged from mild to severe. Of the patients who were scanned within two days after reporting symptoms, more than half showed no evidence of lung disease. Patients who were scanned three to five days after reporting symptoms showed distinctive patterns in their lungs.  

Dr. Chung, the study’s senior author, is an Assistant Professor of Diagnostic, Molecular and Interventional Radiology, and Medicine (Cardiology). Dr. Bernheim, the first author, is an Assistant Professor of Diagnostic, Molecular and Interventional Radiology. According to the authors, “Prompt recognition of the disease is invaluable to ensure timely treatment, and from a public health perspective, rapid patient isolation is crucial to containment of this communicable disease.” 

The doctors say CT imaging is an efficient tool that is generally available throughout the world, even in places with more limited resources. The established imaging patterns of COVID-19 will provide doctors with the evidence they need to look for when making a diagnosis.

Early in the disease phase, the radiologists described a look of “ground-glass abnormality,” in the lungs. As the disease progressed, it was followed by what they called a look of “crazy paving,” which was followed by “increasing consolidation.” This imaging road map, they say, will help physicians predict disease progression and the development of complications.

For physicians, the most critical element in the severity of COVID-19 is the degree to which the lungs fill with fluid, with the worst outcome being the patient succumbing to pneumonia.

“The normal lung is black because it’s composed of air,” says Dr. Chung. “But in a patient with COVID-19 or another severe pneumonia, those areas become filled with cells, debris, pus, and fluid, and become white. That is a diseased lung that is not aerating, not exchanging oxygen and carbon dioxide. If it’s extensive enough and severe enough, and the body’s inflammatory response and immune system’s response can also cause downstream complications at the cellular level, that would make it difficult to oxygenate and could become fatal.”

Why some patients have more severe cases of the disease than others is still unknown, says Dr. Bernheim. He says that even though COVID-19 is in the same viral family as the SARS and MERS coronaviruses and “probably affects the lungs the same way, we are treating this as a new entity. We will have to see how it changes, progresses, and resolves, and treat it as a new area of research as opposed to just comparing it to SARS and MERS.”

Drs. Chung and Bernheim worked with Zahi Fayad, PhD, and his team at the Icahn School of Medicine at Mount Sinai’s newly renamed BioMedical Imaging and Engineering Institute, which creates novel imaging programs and medical technology. Dr. Fayad is the Institute’s Director.