Satisfactory Switch to Infliximab after Adalimumab Loss of Response in a Teenager with Severe Crohn`s Disease

Introduction: Paediatric inflammatory bowel disease is often more aggressive compared to adults and the current tendency is early use of monoclonal antibodies in severe cases, loss of response being the therapeutic challenge.

We present the case of a teenager with Crohn`s Disease, naive to anti-TNF therapy who developed antibodies to Adalimumab and was switched to Infliximab.

Case Presentation: A 13 years old teenager was admitted for alopecia areata, nummular eczema, abdominal pain and weight loss (17 kg) lasting for three months. His mother reported repeated episodes of diarrhea but he denied.

He was diagnosed with Crohn`s Disease and Pediatric Crohn`s Disease Activity Index score was 60, reflecting a severe disease activity. He was started on exclusive enteral nutrition as induction therapy with a good response. We decided to introduce azathioprine not steroids(CS) based on his reluctance to receive CS due to adverse effects. After six months he presented bloody stools and after nine months he developed anal abscess and perianal fistulae which required surgical intervention. Anti-TNF agent Adalimumab was introduced in the treatment plan. After the first 3 months, the seric level of Adalimumab was low and he developed antibodies to Adalimumab accompanying symptoms. We stopped Adalimumab and initiated treatment with Infliximab which he has been receiving for 20 months now with two relapses addressed by dose increase and rhythm adjustment.

Discussions and Conclusion: In naïve patients loss of response to Adalimumab is expected to be rarer. A loss of response to Infliximab may affect the response to subsequent Adalimumab treatment based on cross-reactivity of antibodies even though the two drugs are different idiothypes. However, there is a general lack of experience on the use of Infliximab after Adalimumab failure.

In Crohn`s Disease treatment strategy, Infliximab might be a solution after Adalimumab loss of response due to Adalimumab antibodies development.