Retina showing reticular pseudodrusen. Although they can infrequently appear in individuals with no other apparent pathology, their highest rates of occurrence are in association with age-related macular degeneration (AMD), for which they hold clinical significance by being highly correlated with end-stage disease sub-types, choroidal neovascularisation and geographic atrophy. Credit: National Eye Institute
The drug minocycline, an antibiotic that also decreases inflammation, failed to slow vision loss or expansion of geographic atrophy in people with dry age-related macular degeneration (AMD), according to a phase II clinical study at the National Eye Institute (NEI), part of the National Institutes of Health.
Dry AMD affects the macula, the part of the retina that allows for clear central vision. In people with dry AMD, patches of photoreceptors and their nearby support cells begin to die off, leaving regions known as geographic atrophy. Over time, these regions expand, causing people to lose more and more of their central vision.
Microglia, immune cells that help maintain tissue and clear up debris, are present at higher levels around damaged retinal regions in people with dry AMD than in people without AMD. Scientists have suggested that inflammation – and particularly microglia – may be driving the expansion of geographic atrophy regions.
This study, led by Tiarnan Keenan, MD, PhD, a Stadtman Tenure-Track Investigator at the NEI’s Division of Epidemiology and Clinical Applications, tested whether inhibiting microglia with minocycline might help slow geographic atrophy expansion and its corresponding vision loss.
The trial enrolled 37 participants at the NIH Clinical Center in Bethesda, Maryland, and at the Bristol Eye Hospital, United Kingdom.
After a nine-month period where the researchers tracked each participant’s rate of geographic atrophy expansion, the participants took twice-daily doses of minocycline for two years.
The researchers compared each participant’s rate of geographic atrophy expansion while taking minocycline to their baseline rate, and found there was no difference in geographic atrophy expansion rate or vision loss with minocycline.
Previous studies have shown that minocycline can help reduce inflammation and microglial activity in the eye, including the retina.
The drug has shown beneficial effects for conditions such as diabetic retinopathy, but has not previously been tested for dry AMD.
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New research reported in the journal Nature could lead to new targeted treatments for rheumatoid arthritis (RA). The findings showed that guesswork could be taken out of selecting treatments for each patient, and this might one day also be extended to other autoimmune conditions.
The study was led by University of Colorado School of Medicine faculty members Fan Zhang, PhD, and Anna Helena Jonsson, MD, PhD. The Accelerating Medicines Partnership: Rheumatoid Arthritis and Systemic Lupus Erythematosus (AMP: RA/SLE) Network collected inflamed tissue from 70 patients with RA from across the country and the United Kingdom. Jonsson supervised the team of scientists who processed these samples for analysis, and Zhang led the computation analysis of the data. These efforts yielded a cell atlas encompassing more than 300 000 cells from synovial tissue. Further analysis revealed that there are six different subgroups of RA based on their cellular makeup.
“We hope the data will help us discover new treatment targets,” says Jonsson, assistant professor of rheumatology. “We wanted to make it public so that researchers across the country and across the world can continue working on new treatment ideas for rheumatoid arthritis going forward.”
No more guess-and-check
Jonsson, a practicing rheumatologist as well as a researcher, knows that RA patients respond differently to different treatments. Until now, she says, rheumatologists used a “guess and check” method to find a treatment that works for an individual patient.
With the new data and powerful computational classification methods developed by Zhang and the computational analysis team, the researchers were able to quantitatively classify RA types into what they call ‘cell-type abundance phenotypes’, or CTAPs. Developed methods, together with the new cell atlas, can start to identify which patients will respond to which treatments.
“Even when you classify rheumatoid arthritis inflammation using these simple markers – T cell markers, B cells, macrophages and other myeloid cells, fibroblasts, endothelial cells – what we found is that each of those categories is associated with very specific kinds of pathogenic cell types we’ve already discovered,” Jonsson says. “Previous rheumatoid arthritis research found that T cell populations called peripheral helper T cells are relevant in rheumatoid arthritis, as are B cells called antibody-producing B cells, and other specific cell types. What we found is that they’re usually not found all together.
“For example, the peripheral helper cells are found with the B cells in only one category of RA, and the pathogenic macrophage populations tend to exist in a different category. Because of this, we can start asking questions about how these specific partners work together.”
Researchers have shown that severe inflammation during hospitalisation for COVID increases post-recovery mortality risk by 61% – but this risk is reduced again by 51% if anti-inflammatory steroids are prescribed upon discharge. We need to think of COVID as a potentially chronic disease that requires long-term management, argue the authors, whose results are published in Frontiers in Medicine.
Evidence continues to gather that ‘long COVID’, that is, continued negative health impacts months after apparent recovery from severe COVID, is an important risk for some patients. For example, researchers showed last December that hospitalised patients who seemingly recovered from severe COVID run more than double the risk of dying within the next year, compared to those with only mild COVID or who never had COVID.
Now, the same research team shows that among patients hospitalised for COVID who seemingly recovered, severe systemic inflammation during their hospitalisation is a risk factor for death within one year.
“Here we show that the stronger the inflammation during the initial hospitalisation, the greater the probability that the patient will die within 12 months after seemingly ‘recovering’ from COVID.”
Professor Arch G Mainous III
“COVID is known to create inflammation, particularly during the first, acute episode. Our study is the first to examine the relationship between inflammation during hospitalisation for COVID and mortality after the patient has ‘recovered’,” said first author Professor Arch G Mainous III at the University of Florida Gainesville.
“Here we show that the stronger the inflammation during the initial hospitalisation, the greater the probability that the patient will die within 12 months after seemingly ‘recovering’ from COVID.”
Prof Mainous and colleagues analysed electronic health records of 1207 adults hospitalised with COVID in 2020 or 2021 within the University of Florida health system, with at least a one year follow-up after discharge. As a proxy for the severity of systemic inflammation during hospitalisation, they used a common and validated measure: C-reactive protein (CRP), secreted by the liver in response to a signal by active immune cells.
Widespread inflammation in the body
As expected, the blood concentration of CRP during hospitalisation was strongly correlated with the severity of COVID: 59.4mg/L for patients not needing supplemental oxygen, 126.9 mg/L for those who needed extra oxygen without mechanical ventilation, and 201.2 mg/L for the most severe cases, who required ventilation through a ventilator or through ECMO.
After correcting for risk factors, patients with the highest CRP concentration measured their during their hospital stay had a 61% greater risk of all-cause mortality within one year of discharge than patients with the lowest CRP concentration.
Prof Mainous said: “Many infectious diseases are accompanied by an increase in inflammation. Most times the inflammation is focused or specific to where the infection is. COVID is different because it creates inflammation in many places besides the airways, for example in the heart, brain, and kidneys. High degrees of inflammation can lead to tissue damage.”
Importantly, the authors showed that the increased all-cause mortality risk associated with severe inflammation was reduced again by 51% if the patient was prescribed anti-inflammatory steroids after their hospitalisation.
These results mean that the severity of inflammation during hospitalisation for COVID can predict the risk of subsequent serious health problems, including death, from ‘long COVID’. They also imply that current recommendations for best practice may need to be changed, to include more widespread prescription of orally taken steroids to COVID patients upon their discharge.
COVID as a chronic disease?
The authors propose that COVID should be seen as a potentially chronic disease.
“When someone has a cold or even pneumonia, we usually think of the illness being over once the patient recovers. This is different from a chronic disease, like congestive heart failure or diabetes, which continue to affect patients after an acute episode. We may similarly need to start thinking of COVID as having ongoing effects in many parts of the body after patients have recovered from the initial episode,” said Prof Mainous.
“Once we recognise the importance of ‘long Covid’ after seeming ‘recovery’, we need to focus on treatments to prevent later problems, such as strokes, brain dysfunction, and especially premature death.”
