Health Rounds: Mix of bacteria may be the underlying cause of dry eye

Hello Health Rounds Readers! If you suffer from itchy, painful dry eyes, researchers may have discovered the cause and a possible path to better treatments. We also feature research that may explain some of the symptoms COVID patients endure. And we cover a study about an AI system that could head off the need for emergency intervention of hospitalized patients.

Unhealthy mix of microbes may cause 'dry eye'

Healthy eyes and “dry” eyes have different mixes of microbes living in them, according to findings from a small study that may lead to improved treatments for various eye problems, researchers said.

Dry eye, or keratoconjunctivitis sicca, occurs when the eyes do not produce enough tears or the tears don't work properly, often resulting in pain and vision problems.

For a study presented at the annual meeting of the American Society for Biochemistry and Molecular Biology in San Antonio, researchers used genetic analysis technology to determine how the mix of microbes in healthy eyes differs from those found in patients with dry eye.

In 30 volunteers, they found that Streptococcus and Pedobacter bacteria species were the most prevalent microbes in healthy eyes, while more Acinetobacter species were present in dry eyes.

“We think the metabolites produced by these bacteria are responsible for dry eye conditions,” said Pallavi Sharma, a graduate student at Stephen F. Austin State University in Nacogdoches, Texas.

“We are performing further research to understand the metabolic pathways associated with the Acinetobacter to better understand the disease.”

The researchers would also like to explore the gut microbiome of the patients with dry eye to better understand whether and how it may relate to the eye microbe differences they observed.

“Human microbiome research suggests a strong connection between the gut microbiome and the brain and eyes,” said Sharma.

“Any alteration in the gut microbiome affects other organs and can lead to disease," Sharma added.

Antibodies acting as enzymes may explain COVID features

Antibodies that act like enzymes may explain some of the mystifying symptoms associated with COVID-19, early findings from a study of patients' blood samples suggest.

In the analysis of blood samples obtained from 67 volunteers with moderate or severe COVID-19 on day 7 of hospitalization, researchers found a small subset had antibodies that acted like enzymes that regulate blood pressure.

Patients may also be making antibodies that activate enzymes involved in blood clotting and inflammation, the researchers said.

Typically, antibodies recognize and attack viruses and bacteria, while enzymes initiate or accelerate various processes in the body. Molecules called “abzymes,” which can perform both functions, have been seen before in patients with immune system disorders, according to a report in the American Society for Microbiology’s mBio.

When the virus that causes COVID begins to infect a cell, the spike protein on the surface of the virus attaches itself to an enzyme on the cell surface called ACE2. Some patients make antibodies against the spike protein that so closely resemble ACE2 that they also have enzymatic activity like ACE2, the researchers found.

Unfortunately, the researchers were not able to track their volunteers over time and so could not determine whether the abzymes were associated with patients’ clinical course.

“If COVID-19 patients are making abzymes, it is possible that these rogue abzymes could harm many different aspects of physiology,” study leader Dr. Steven Zeichner of the University of Virginia School of Medicine said in a statement.

“If this turns out to be true, then developing treatments to deplete or block the rogue abzymes could be the most effective way to treat the complications of COVID-19."

AI can flag hospital patients before they 'crash'

Early-warning computer programs built with artificial intelligence (AI) are very effective at identifying hospitalized patients who are at risk for sudden critical health deterioration, enabling doctors to intervene and stabilize them, a study at one hospital found.

Among 9,938 patients hospitalized in 2021 and 2022 in general internal medicine units, use of the Epic Deterioration Index (EDI) designed by Epic Systems Corp was associated with a 10.4–percentage point reduction in the risk of a rapid response team activation, transfer to the intensive care unit, or cardiopulmonary arrest during hospitalization, according to a report in JAMA Internal Medicine.

Hundreds of hospitals are already using the same or similar AI software. Despite widespread adoption, they have not been tested in many rigorous studies, the authors said.

“This study provides evidence for their effectiveness and supports further testing of these interventions in other care settings,” they concluded.