Paradoxical gastrointestinal reactions in patients taking tumor necrosis factor inhibitors: a rare event that broadens the histologic spectrum of medication–associated injury

Inflammatory Bowel Disease as a Paradoxical Reaction to Anti-TNF-α Treatment-A Review

TNF-α inhibitors (TNFis) have revolutionized the treatment of certain chronic immune-mediated diseases, being widely and successfully used in rheumatic inflammatory diseases, and have also proved their efficacy in the treatment of inflammatory bowel disease (IBD). However, among the side effects of these agents are the so-called paradoxical effects. They can be defined as the appearance or exacerbation of a pathological condition that usually responds to this class of drug while treating a patient for another condition. A wide range of paradoxical effects have been reported including dermatological, intestinal and ophthalmic conditions. The causal mechanism of occurrence may implicate an imbalance of cytokines, but is still not fully understood, and remains a matter of debate. These paradoxical reactions often show improvement on discontinuation of the medication or on switching to another TNFi, but in some cases it is a class effect that could lead to the withdrawal of all anti-TNF agents. Close monitoring of patients treated with TNFis is necessary in order to detect paradoxical reactions. In this study we focus on reviewing IBD occurrence as a paradoxical effect of TNFi therapy in patients with rheumatological diseases (rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis, and juvenile idiopathic arthritis).

Paradoxical Reactions to Biologicals in Chronic Inflammatory Systemic Diseases

BACKGROUND

Biological agents that contain substances affecting the immune system are increasingly being used to treat chronic inflammatory systemic diseases. Aside from the expected adverse effects, they can also induce unexpected paradoxical reactions (PR). A reaction is called paradoxical when a substance that is generally therapeutically effective induces the opposite of what is intended, with the new appearance or exacerbation of inflammatory changes in the skin and other organs.

METHODS

The paradoxical reactions that have been described since 1997 are presented here on the basis of the available literature on the main types of chronic inflammatory systemic disease, which was retrieved by a selective search in the PubMed and Google Scholar databases.

RESULTS

Many studies and registers to date contain no mention of paradoxical reactions. Anti- TNF-alpha treatment for patients with ankylosing spondylitis leads to paradoxical reactions in 19 per 1000 patient years, compared to 11 per 1000 patient years with conventional treatment; the corresponding frequency for paradoxical psoriasis in patients with other chronic inflammatory systemic diseases are 1.04-3.68 versus 1.45 per 1000 patient years. Paradoxical reactions tend to be more common with anti-TNF-alpha treatment than, for example, with the administration of ustekinumab, vedolizumab, and other agents. It is unclear whether some drugs have been noted to cause PR more commonly than others because of varying times since their approval, differences in immunogenicity, and differences between their target structures.

CONCLUSION

Paradoxical reactions induced by biological agents are a problem confronting physicians in multiple specialties. They need to be distinguished from infectious and neoplastic diseases and from autoimmune conditions of other types. The treatment options for paradoxical reactions include local treatment, symptomatic therapy, prednisolone administration, and the discontinuation or switching of the biological agent, although some patients will react with a further paradoxical reaction to a different biological agent that is used instead.

Gastrointestinal Adverse Drug Reaction Profile of Etanercept: Real-world Data From Patients and Healthcare Professionals

OBJECTIVE

We aimed to describe the nature and frequency of gastrointestinal adverse drug reactions (GI-ADRs) of etanercept (ETN) using patient-reported and healthcare professional (HCP)-registered data and compared this frequency with the GI-ADR frequency of the widely used tumor necrosis factor-α inhibitor adalimumab (ADA).

METHODS

Reported GI-ADRs of ETN for rheumatic diseases were collected from the Dutch Biologic Monitor and DREAM registries. We described the clinical course of GI-ADRs and compared the frequency with ADA in both data sources using Fisher exact test.

RESULTS

Out of 416 patients using ETN for inflammatory rheumatic diseases in the Dutch Biologic Monitor, 25 (6%) patients reported 36 GI-ADRs. In the DREAM registries 11 GI-ADRs were registered for 9 patients (2.3%), out of 399 patients using ETN, with an incidence of 7.1 per 1000 patient-years. Most GI-ADRs consisted of diarrhea, nausea, and abdominal pain. GI-ADRs led to ETN discontinuation in 1 patient (4%) and dose adjustment in 4 (16%) in the Dutch Biologic Monitor. Eight GI-ADRs (73%) led to ETN discontinuation in the DREAM registries. The frequency of GI-ADRs of ETN did not significantly differ from GI-ADRs of ADA in both data sources (Dutch Biologic Monitor: ETN 8.7% vs ADA 5.3%, P = 0.07; DREAM: ETN 2.8% vs ADA 4.7%, P = 0.16).

CONCLUSION

Most GI-ADRs associated with ETN concerned gastrointestinal symptoms. These ADRs may lead to dose adjustment or ETN discontinuation. The frequency of ETN-associated GI-ADRs was comparable to the frequency of ADA-associated GI-ADRs. Knowledge about these previously unknown ADRs can facilitate early recognition and improve patient communication.