Normal calprotectin but flare?

[newdiagnosis]

Hi,
I've been on stelara for around 7 years and last colonoscopy few months ago was completely clear. However, Recently I extended out my injections from q6 weeks to q8-10 weeks and developed a flare. However, my calprotectin levels are normal. Seem to be better on a short course of steroids. Can you still have a flare when calprotectin is around 10? How long does it typically take to get this flare under control?

 

[Scipio]

Can you still have a flare when calprotectin is around 10?

One thing I have learned about Crohn's is that anything is possible, including many things that contradict our current understanding of how the disease should behave.

The thing to remember about fecal calprotectin (FCP) is that it is produced by neutrophils (a type of white blood cell), and thus reflects only one aspect of Crohn's inflammation - namely the degree of neutrophil infiltration and activation in the gut. There are many things going on in active Crohn's disease besides or beyond neutrophil activation.

You could have a flare with low fecal calprotectin levels if the site of the Crohn's inflammation is high upstream in the small bowel rather than down in the colon. Calprotectin is not a particularly stable protein, and much of it degrades as is travels down the gut from the small bowel into the colon and out the end to be tested. Or, alternatively, you could be experiencing a flare that, for whatever reason, did not involve a lot of neutrophil infiltration into the gut. It's hard to say.

Inflammation is a complex process that involves a lot more than just the neutrophils. Fecal calprotectin is a good, but not perfect, method of assessing Crohn's inflammation. The FCP test may have simply missed this one.

 

[newdiagnosis]

Yes it is complex. Hoping that this flare gets under control going back to every 4 week stelara..