We need to try to understand why this increase in prevalence is occurring, and why is it occurring in this specific patient?”
– Tony Guerrerio, MD, PhD
The director of the Very Early Onset Inflammatory Bowel Disease Clinic discusses the increasing prevalence of IBD among young children and genetic approaches to diagnose and treat it.
How would you characterize the incidence of IBD today?
Inflammatory bowel disease, which includes Crohn’s disease and ulcerative colitis, affects between 1.5 million and 3 million Americans, of which 6% are diagnosed in the very early onset — less than 6 years of age. The incidence of IBD in the adult population appears to be stable, while the diagnosis in children under 6 is increasing.
Why is that?
We don’t know. We do know that the increase is occurring here in the United States and in newly industrialized countries that have transitioned to westernized culture and diet. Susceptibility appears to be a combination of a patient’s genetics, immune response and environment. We need to try to understand why this increase in prevalence is occurring — and why is it occurring in this specific patient?
Could you elaborate?
We’re still working to understand who is going to develop IBD. We know it’s a complex interplay of the individual’s genetics, their environmental exposures, and their microbiome, the collection of different bacterial species that live in their intestines. In a person with the right genetics and the right microbiome, something happens in the environment that tips things over the edge and leads to the development of inflammation and white blood cells that are acting like there’s an infection when there isn’t one. What are the susceptibilities, and who are the at-risk people we need to pay attention to?
So how do you diagnose early onset IBD?
Through the patient’s history, symptoms, results from blood work and tests on stool, as well as imaging and biopsy results from endoscopy and colonoscopy. Also, all patients who come to our center get an immunologic workup and evaluation. If you have immune dysregulation, that may make you more susceptible to inflammatory bowel disease. Also, there are certain genetic conditions that make you more susceptible to inflammatory bowel disease, so we also use whole exome sequencing to search for gene defects in children 5 years and under. We sometimes do targeted sequencing of specific genes as well.
Which tells you what?
Certain DNA changes alert us to look for different treatments specific to addressing the particular pathway that protein is in. Also, if we find something that we think might be important but has not been reported in the literature, working with our colleagues in genetics we’re able to investigate that further and expand our understanding of how certain genetic changes affect a person’s susceptibility to developing IBD.
What are the treatment options?
The two main ones used today are topical medicines, which coat the inside of the intestines and help fight inflammation, and biologics — antibodies that block very specific signaling molecules between white blood cells. These molecules are particularly active in IBD. We also work with our IBD dieticians, to use food and other dietary interventions both as medicine and to maximize nutrition.
Does surgery come into play?
Some patients with very early onset IBD require surgery for problems. At Johns Hopkins Children's Center we have excellent colleagues in pediatric surgery as part of our team taking care of our pediatric IBD patients. Sometimes our surgical colleagues will see a patient with signs of early onset IBD before we do, suspect IBD and refer the patient to us.