Introduction
Selecting the right treatment in the early stages of inflammatory bowel disease (IBD) is essential for preventing disease progression and modifying disease course. Intestinal ultrasound (IUS) is a promising tool in predicting early treatment response. We aimed to systematically review current literature on the predictive value of IUS for treatment response.
Aims & Methods
A literature search was performed on the 24th of October and updated on the 26th of March 2024 using PubMed, Medline, Embase, Cochrane Library and Cinahl. We included articles in paediatric and adult IBD patients where IUS was used for the assessment of treatment. Studies were grouped based on timing of IUS after start of treatment. In acute severe ulcerative colitis (ASUC) timing included within 5 days or between 6-14 days. In ulcerative colitis (UC) or Crohn’s disease (CD) baseline, 0-3 weeks, 4-8 weeks, 12-16 weeks and >16 weeks were used. Additional response assessments included clinical or endoscopic disease activity scores and adverse events (e.g. surgery, hospitalization, treatment escalation).
Results
Out of 1739 unique articles, 27 were included with 17 in CD, 6 in UC and 4 in ASUC.
Baseline IUS parameters were not predictive of treatment response in CD, UC or ASUC.
In CD, most studies investigated response to anti-TNF (n=12), though multiple therapies were evaluated (n=5). For anti-TNF, IUS was predictive of response to therapy at all time points from 2 weeks onward. IUS at week 4 to 8 showed conflicting results in studies using multiple treatments. After 12 weeks, IUS predicted clinical and endoscopic outcomes as well as adverse events in all studies regardless of treatment. Lastly, an IUS several months after starting treatment predicted clinical response, adverse events and endoscopic response in the follow years.
A variety of medical treatments were included in most UC studies (n=3). IUS within 3 weeks of treatment initiation was able to predict both short- and long-term clinical response in UC. Endoscopic response could be predicted by IUS after 6 weeks. The combination of BWT and colour Doppler signal (CDS) measured at 3 and 9 months of therapy predicted endoscopic activity after 9 and 15 months, respectively.
In ASUC, bowel wall thickness (BWT) significantly differed between responders and non-responders of intravenous steroid treatment when measured 1-3 days after treatment initiation.
| IUS time point | Drug* | Clinical outcomes | Adverse outcomes** | Endoscopic outcomes |
| CD | <3 weeks | Anti-TNF
MT | Yes |
No | Yes |
| 4-8 weeks | Anti-TNF
USTE
MT | Yes
Yes |
Inconclusive | Yes
Yes
Yes |
| 12-16 weeks | Anti-TNF
USTE
MT |
Yes |
Yes | Yes
Yes
Yes |
| >16 weeks | Anti-TNF
MT |
Yes | Yes | Yes
Yes |
ASUC
| 1-5 days
6-21 days
| CS
CS
| Yes
Yes
| Yes
Yes
|
|
| UC | <3 weeks | CYTA
MT | Yes
Yes |
|
No |
| 4-8 weeks | MT |
|
| Yes |
| 12-16 weeks | CS
MT |
|
| Yes
Yes |
| >16 weeks | CS |
|
| Yes |
* CS=corticosteroids | MT=multiple treatments |CYTA=cytapheresis | USTE=Ustekinumab
**Hospitalization, surgery, treatment escalation or no discontinuation of corticosteroids
Conclusion
IUS performed at 1-3 days, 2 weeks and 6 weeks was predictive of treatment response in ASUC, CD and UC, respectively. Further data is needed to characterize IUS response kinetics of the individual therapies.
Disclosure
J.M.B.W. Vos: None
C. Teichert: None
F.A.E. De Voogd: received speaker or honoraria fees from AbbVie, Janssen, Galapagos, Pfizer and Takeda
G.R.A.M. D’Haens: received research grants from Abbvie, Alimentiv, BMS, J&J, Pfizer, Takeda; consulting fees from Abbvie, Agomab, Alimentiv, AstraZeneca, AMT, Bristol Meiers Squibb, Boehringer Ingelheim, Celltrion, Eli Lilly, Exeliom Biosciences, Galapagos, Index Pharmaceuticals, Kaleido, Glaxo Smith Kline, Gossamerbio, Pfizer, Immunic, Johnson and Johnson, Polpharma, Procise Diagnostics, Prometheus laboratories, Prometheus Biosciences, Progenity, Protagonist, and Ventyx; speaker’s fees from Abbvie, Arena, Boehringer Ingelheim, Celltrion, Galapagos, Gilead, Pfizer, BMS, and Takeda; data monitoring board: Galapagos, AstraZeneca, Seres Health.
B.G.P. Koot: None
K.B. Gecse: received grants from Pfizer Inc, Celltrion, and Galapagos; consultancy fees from AbbVie, Arena Pharmaceuticals, Galapagos, Gilead, ImmunicTherapeutics, Janssen Pharmaceuticals, Novartis, Pfizer Inc., Samsung Bioepis, and Takeda; and speaker’s honoraria from Celltrion, Ferring, Janssen Pharmaceuticals, Novartis, Pfizer Inc, Samsung Bioepis, Takeda, and Tillotts.