Inflammatory bowel diseases, including Crohn’s disease and ulcerative colitis, are chronic inflammatory diseases of the bowel. These diseases can develop as a result of genetic or environmental factors, such as smoking, diet, or any alteration of the normal human gut flora. These factors spur a progressive immune response, which in turn creates mucosal damage to the GI tract.
Symptoms of inflammatory bowel disease run the gamut from diarrhea, abdominal pain, and perianal fistulas to fatigue, weight loss, and/or bowel obstruction. While ulcerative colitis is more closely associated with changes to the inner lining of the colon, Crohn’s disease can affect any segment of the gastrointestinal tract: all the way from mouth to anus.
Treatment for Crohn’s disease focuses on two main types of medications: anti-inflammatory agents and biological treatments. The biological treatments include many medication options: Humira, Remicade, Cimzia, Stelara, Entyvio, and Tysabri. These medications work to alter the immune response of the immune system, by targeting specific proteins that cause inflammation. Humira, for example, targets a protein called TNF-alpha.
Crohn’s disease biological medications can bring great benefits to patients; but unfortunately it is not uncommon for a particular medication to become less effective over time. However, monitoring certain elements of the immune system can guide future treatment. Specifically, monitoring levels of adalimumab antibodies (ATAs) can allow determination if a patient needs a dose increase or if it is appropriate for the patient to switch to another medication within the same drug class. It appears that low trough concentrations may be reflective of a loss of response to Humira (trough levels less than or equal to 5 mcg/ml). In this case, testing for antibodies is suggested. For trough concentrations above 5 mcg/ml, the presence of antibodies are not likely, so the patient may benefit from an increased dose. It was also suggested that adalimumab concentration results above 35 mcg/mL should be drawn at a different time-point other than trough.
Overall ATA testing could lead to a more appropriate and cost-effective management strategy for patients with Crohn’s disease, which is part of an overall move to more personalized treatment of disease.