Covid directly affects kidneys, can cause tissue scarring, claims study

It is well documented that the COVID-19 virus mainly affects the lungs, but a new study has claimed that the infection also has the capability to damage kidneys as well.

According to a study by a team of German and Dutch scientists, COVID-19 causes direct cellular damage within the kidneys, contributing to tissue scarring or kidney fibrosis.

The study was published in the journal Cell Stem Cell.

To study the effects of SARS-CoV-2 on the kidney, the scientists at the RWTH Uniklinik Aachen in Germany and the Radboud University Medical Center in the Netherlands collected kidney tissue of 62 COVID-19 ICU patients (61 autopsy specimens and one biopsy).

They then compared these kidney tissues of Covid patients, other patients in the hospital for a non-Covid-related lung issue, and a group of healthy people.

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They found out that the kidney tissue from the COVID-19 patients showed much more tissue scarring than others.

After establishing that COVID-19 damages the kidneys, the researchers then set out to determine how the virus accomplishes this.

The team created a series of mini kidneys, called organoids, by culturing them in a lab. Developed using stem cells, the organoids featured many different kidney cells, except immune cells.

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The scientists then infected each organoid with a live Covid virus to observe the direct impact on kidney cells.

Once again, scientists noted kidney organoid scarring as well as “accompanied signals that contribute to the scarring process.”

These findings strongly indicate that the coronavirus itself, not inflammation or any other systemic effects, is responsible for the observed kidney damage seen in COVID-19 patients, the researchers noted.

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“In our study, we thoroughly investigated the causal damaging effects of the Coronavirus in the kidneys. The infected kidney organoids show that the virus directly causes cell damage, independent of the immune system. With this work, we found a piece of the puzzle showing the deleterious effects the virus can have in the body,” says co-researcher Jitske Jansen in a media release.

“Kidney fibrosis, or scarring, is a serious long-term consequence that can occur virtually after any injury to the kidney and correlates with kidney function. Our work shows kidney scarring in COVID-19 patients, which provides an explanation why the virus might cause kidney functional decline as demonstrated in other studies. Long-term follow-up studies will provide further insights into kidney-related pathologies caused by SARS-CoV-2,” co-researcher Katharina Reimer concludes.

(With inputs from agencies)