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Careful monitoring of infliximab-treated patients is necessary after COVID injection
Infliximab, a powerful biologic used to treat inflammatory bowel disease (IBD), attenuates the body’s immune response to COVID-19 infection, indicates research published online in the journal. Intestine.
This altered response may increase susceptibility to recurrent COVID-19 and help drive the evolution of new variants of SARS-CoV-2, the virus responsible for the infection, the researchers warn.
Careful monitoring of IBD patients treated with infliximab after vaccination against COVD-19 will be needed to ensure that they elicit an antibody response strong enough to prevent infection, they advise.
Infliximab belongs to a class of medications called anti-tumor necrosis factor (anti-TNF) drugs. These drugs suppress the production of an inflammatory protein involved in the development of several conditions, including ulcerative colitis and Crohn’s disease, which are types of inflammatory bowel disease.
Around 2 million people worldwide are treated with anti-TNF drugs, which are known to affect protective immunity after vaccination against pneumonia, influenza, and viral hepatitis, in addition to increasing the risk of serious infections, particularly respiratory infections.
Because of these risks, patients taking these medications have been advised to protect themselves during the coronavirus pandemic and / or take extra precautions to minimize the risk of contracting COVID-19.
With these issues in mind, the researchers wanted to find out whether anti-TNF drugs could also blunt the body’s immune response to SARS-CoV-2. Therefore, they compared antibody responses to SARS-CoV-2 in IBD patients treated with infliximab or another biologic called vedolizumab.
Vedolizumab is an intestinal monoclonal antibody that has a similar dosing schedule to infliximab. But it is not associated with increased susceptibility to systemic infection or weakened immune responses to vaccination.
In total, 6,935 IBD patients (mean age 39 years) were recruited from 92 UK hospitals between September and December 2020 for the CLARITY IBD study: around two-thirds (4,685) of them were being treated with infliximab and around of a third (2250) with vedolizumab. .
Almost 40% (2,589 of 6,935) had been swabbed (PRC) for SARS-CoV-2. And the rates of symptomatic and confirmed SARS CoV-2 infection were similar in both treatment groups.
Some 389 (8%) in the infliximab group and 201 (9%) in the vedolizumab group had symptoms suggestive of COVID-19 infection; 89 of 1,712 of those taking infliximab tested positive for the virus (just over 5%) as did 38 of 877 (just over 4%) of those taking vedolizumab.
But fewer patients treated with infliximab had detectable antibodies to the virus in their blood than those treated with vedolizumab: 3.4% (161/4685) versus 6% (134/2250).
And only about half (48%; 39/81) of infliximab-treated patients whose COVID-19 infection was confirmed by a smear test subsequently developed antibodies compared to 83% (30/36) of those treated. with vedolizumab.
And the addition of other drugs commonly used to reduce the inflammatory response, such as thiopurine or methotrexate, further reduced the antibody response to SARS-CoV-2 in patients treated with infliximab, of whom only a third had detectable antibodies. against SARS-CoV. -two.
An increase in antibodies to SARS-CoV-2 was observed 4 weeks after a positive smear test in patients taking vedolizumab, but not in those treated with infliximab.
“Similar rates of proven and symptomatic SARS-CoV-2 infection and hospitalizations between infliximab-treated and vedolizumab-treated patients suggest that our findings cannot be explained by differences in infection acquisition or severity alone. More well, infliximab appears to be directly influencing the serological response to infection, “the researchers explain.
“Infliximab can directly hinder the immune mechanisms responsible for generating antibody responses,” they suggest.
This is an observational study, so you cannot establish the cause. And the researchers acknowledge certain limitations of their study, including the fact that weakened immune responses in patients treated with infliximab do not automatically translate into an increased risk of infection.
Protective immunity after vaccination involves more than just antibodies. And the only anti-TNF drug studied was infliximab.
However, they suggest that a weakened antibody response has potentially far-reaching implications.
It can increase susceptibility to recurrent COVID-19 in patients treated with infliximab, which could lead to chronic colonization of the virus in the nose and throat. This “may act as a repository to drive the persistent transmission and evolution of new SARS-CoV-2 variants,” they warn.
And they conclude: “Serological testing and virus surveillance to detect suboptimal vaccine responses, persistent infection, and viral evolution should be considered to inform public health policy.”
“If attenuated serological responses are also seen after vaccination, it will be necessary to design modified immunization strategies for millions of patients worldwide.”
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External peer review? Yes
Type of evidence: observational
Topics: People
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