Spondyloarthritis (SpA) is a disease which may be triggered and maintained by Dysbiosis. Up to 50% of Ankylosing Spondylitis patients may have silent ileitis. Inflammatory Bowel Diseases like Crohn's Disease and Ulcerative Colitis are known to be associated with AS.
It may therefore be useful to routinely screen for gut inflammation in SpA patients, especially in those with abdominal symptoms, or those who appear to respond inadequately to treatment. Stool calprotectin is a convenient and reliable, albeit expensive, screening method.
However, less clear at this point is what to do with a positive result:
1) Should endoscopy, CT abdomen and other tests (eg ASCA, ANCA, ATTG etc serologies) follow?
2) How should we treat it? Do antibiotics and probiotics help?
3) Should we avoid anti-IL17A therapy, since there appears to be an association with aggravation of Crohn's?
It bears noting that proton-pump inhibitors (PPI), often given for gastric or reflux symptoms, can raise the calprotectin. It is not clear whether this is a direct effect, or an indirect one through acid obliteration permitting dysbiosis. PPIs are bad drugs in my book (associated with pneumonia, C difficile infection, osteoporosis), and should not be routinely prescribed like antacids unless clearly indicated; and then for as short a duration as is necessary.
Crohn's Disease affecting the small intestines is often difficult to diagnose, let alone monitor disease activity and response to various treatments.
Colonoscopy, capsule enteroscopy and CT scans are tedious and expensive.
In the ever-expanding indications of ultrasound, contrast-enhanced ultrasound (CEUS) may now provide a rapid, cheap, safe and accessible evaluation modality at the point-of-care.
This will be a very welcomed monitoring modality, complementing stool calprotectin.