New insight into the effect of hydroxychloroquine undermines its use in COVID-19

November 23, 2020

Researchers at Radboud university medical center have discovered an as yet unknown effect of hydroxychloroquine. It inhibits the action of a type of white blood cells important in the first line of defense against infections. Based on this research, hydroxychloroquine is unlikely to be beneficial in clearing viral infections including the new coronavirus SARS-CoV-2, they write in their publication in Cell Reports Medicine.

Hydroxychloroquine is an agent that has been used for years, originally for the treatment of malaria. It is also widely used to treat patients with rheumatic diseases, because hydroxychloroquine has immunomodulatory effects. It is not known exactly how hydroxychloroquine does this. Hydroxychloroquine use for COVID-19 remains a topic of intense debate and investigation. Especially in the context of their use as a prophylaxis, large studies are ongoing to investigate their efficacy.

Rapid action

In a virus infection, such as the new coronavirus SARS-CoV-2, a good response from the immune system is essential for fighting the virus. If the immune response in the beginning of the infection is insufficient, the virus can spread and cause damage. This uncontrolled infection, which sometimes leads to serious illness or death with SARS-CoV-2, is exactly what you want to prevent.

First responders

Raphaël Duivenvoorden, internist-nephrologist at Radboud university medical center, "We looked at the immune response of patients admitted to the hospital with a SARS-CoV-2 infection. We observed that a certain type of immune cells, the monocytes, play an important role in the first line of defense against the coronavirus. Therefore, we investigated the effect of hydroxychloroquine on these cells.

Impaired defense

Monocytes can develop a type of nonspecific memory, something called "trained immunity". Thanks to this mechanism, monocytes are able to develop a stronger response to bacteria and viruses. In this way, monocytes can contribute to a better and earlier control of invaded micro-organisms. Duivenvoorden, who coordinated the study: "We found that hydroxychloroquine prevents the development of this protective mechanism of "trained immunity". That is why we expect hydroxychloroquine to have no beneficial effect on the immune response in a SARS-CoV-2 infection.

Radboud University Medical Center

Related Immune Response Articles from Brightsurf:

Boosting chickens' own immune response could curb disease
Broiler chicken producers the world over are all too familiar with coccidiosis, a parasite-borne intestinal disease that stalls growth and winnows flocks.

Cells sacrifice themselves to boost immune response to viruses
Whether flu or coronavirus, it can take several days for the body to ramp up an effective response to a viral infection.

Children's immune response more effective against COVID-19
Children and adults exhibit distinct immune system responses to infection by the virus that causes COVID-19, a finding that helps explain why COVID-19 outcomes tend to be much worse in adults, researchers from Yale and Albert Einstein College of Medicine report Sept.

Which immune response could cause a vaccine against COVID-19?
Immune reactions caused by vaccination can help protect the organism, or sometimes may aggravate the condition.

Obesity may alter immune system response to COVID-19
Obesity may cause a hyperactive immune system response to COVID-19 infection that makes it difficult to fight off the virus, according to a new manuscript published in the Endocrine Society's journal, Endocrinology.

Immune response to Sars-Cov-2 following organ transplantation
Even patients with suppressed immune systems can achieve a strong immune response to Sars-Cov-2.

'Relaxed' T cells critical to immune response
Rice University researchers model the role of relaxation time as T cells bind to invaders or imposters, and how their ability to differentiate between the two triggers the body's immune system.

A novel mechanism that triggers a cellular immune response
Researchers at Baylor College of Medicine present comprehensive evidence that supports a novel trigger for a cell-mediated response and propose a mechanism for its action.

Platelets exacerbate immune response
Platelets not only play a key role in blood clotting, but can also significantly intensify inflammatory processes.

How to boost immune response to vaccines in older people
Identifying interventions that improve vaccine efficacy in older persons is vital to deliver healthy ageing for an ageing population.

Read More: Immune Response News and Immune Response Current Events is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to