Biologic inflammatory bowel disease suppresses immune response to COVID-19

Careful examination of patients treated with infliximab required after COVID injection

Infliximab, a powerful biologist used to treat inflammatory bowel disease (IBD), suppresses the body’s immune response to COVID-19 infection, according to research published online in the iris Gut.

This weak response could increase vulnerability to recurrent COVID-19 and help lead the evolution of new mutations of SARS-CoV-2, the virus that is responsible for it. the disease, warn the researchers.

IBD patients treated with infliximab after the COVD-19 vaccination will require careful monitoring to ensure that they are eliciting a strong immune response against the disease, they advise .

Infliximab belongs to a type of medication called anti-tumor necrosis factor (anti-TNF) drugs. These drugs suppress the production of inflammatory proteins that are involved in the development of several conditions, including ulcerative colitis and Crohn’s disease which are types of inflammatory bowel disease.

Approximately 2 million people worldwide are treated with anti – TNF drugs, which are known to weaken immunity after vaccination against pneumonia, influenza and viral hepatitis, as well as increasing the risk of serious diseases, especially respiratory diseases.

Because of these risks, patients taking these drugs have been advised to shield during coronavirus pandemic infection and / or take additional measures to reduce the risk of COVID-19 infection. .

With these issues in mind, the researchers wanted to find out if anti-TNF drugs could adversely affect the body’s immune response to SARS-CoV-2 as well. So they compared the antibody responses to SARS-CoV-2 in IBD patients treated with infliximab or another biologist called vedolizumab.

Vedolizumab is a monoclonal gut antibody that has a dosing schedule similar to that of infliximab. But it is not related to being more susceptible to systemic diseases or immune responses.

In total, 6935 IBD patients (average age 39) were recruited from 92 hospitals in the UK between September and December 2020 for the CLARITY IBD study: about two-thirds (4685) of them were treated with infliximab and about a third (2250) le vedolizumab.

Nearly 40% (2589 out of 6935) were swab-tested (PRC) for SARS-CoV-2. And levels of coarsal and confirmed SARS CoV-2 infection were similar in both treatment groups.

Some 389 (8%) of the infliximab group and 201 (9%) of the vedolizumab group had symptoms of COVID-19 disease; 89 out of 1712 of those taking infliximab were positive for the virus (just over 5%) as were 38 out of 877 (just over 4%) of those taking it. ‘take vedolizumab.

However, fewer patients treated with infliximab with identifiable antibodies to the virus in their blood than those treated with vedolizumab: 3.4% (161/4685) vs. 6% (134/2250).

And only about half (48%; 39/81) of infliximab-treated patients with COVID-19 infection confirmed by a subsequent swab test developed antibodies compared with 83% (30/36) of those treated with vedolizumab.

And the addition of other commonly used drugs to reduce the inflammatory response, such as thiopurine or methotrexate, further disturbed the antibody response to SARS-CoV-2 in infliximab-treated patients. , and only a third of them had antibodies identifiable to SARS-CoV -2.

An increase in antibodies to SARS-CoV-2 was observed 4 weeks after an advanced swab test in patients taking vedolizumab, but not in those treated with infliximab.

“Similar levels of simulated and confirmed SARS-CoV-2 infection and hospitalization between patients with infliximab and vedolizumab treatment suggest that our findings cannot be explained by differences in erection or severity of the disease. disease alone. Instead, infliximab appears to directly affect the serological response to disease, “the researchers explained.

“Infliximab could directly block the immune mechanisms that are responsible for generating antibody responses,” they suggest.

This is a speculative study, so it cannot establish a cause. And the researchers acknowledge that there are some limitations in their study, including that weak immune responses in infliximab-treated patients do not automatically translate to a higher risk. of diseases.

Immunosuppression after vaccination involves more than just antibodies. And the only anti-TNF drug studied was infliximab.

Nonetheless, they suggest that a weak anti-antibody response may have a broader effect.

COVID-19 may be more likely to relapse in patients treated with infliximab, which can then lead to harmful colonization of the virus in the nose and throat. This “could be a reservoir to drive the continued spread and evolution of new SARS-CoV-2 mutations,” they warn.

And they conclude: “Serological testing and virus screening should be considered for suboptimal vaccine responses, chronic disease, and viral evolution to inform public health policy.

“If impaired serological responses after vaccination are also looked at, modified vaccination strategies need to be designed for millions of patients worldwide.”


External peer review? there is

Type of evidence: Observation

Subjects: People

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