Gil Y. Melmed, MD, on Strategies for Treating C. difficile in IBD

Dr Melmed reviews his presentation at the virtual Advances in Inflammatory Bowel Diseases regional meeting on April 16 concerning the treatment of C. difficile infection in patients with ulcerative colitis and Crohn disease.

Gil Y. Melmed, MD, is codirector of Clinical IBD at Cedars-Sinai in Los Angeles, California.
 

TRANSCRIPT:

Dr. Gil Melmed:  Hi, I'm Dr. Gil Melmed from Cedars-Sinai, and it's my pleasure to be speaking to you about a talk that I've just given at AIBD, Advances in Inflammatory Bowel Disease Regional event in Los Angeles on April 16th.

In this talk entitled "Tailored Treatment Strategies for C. Difficile Infection and Recurrence in Inflammatory Bowel Disease," we covered the incidence of C. diff, testing for C. diff, and treatment for C. diff, especially now in the COVID era.

When it comes to understanding C. diff in IBD, we first have to recognize that C. diff is common and has become a lot more common over the past 15 years in patients with inflammatory bowel disease and recognizing that it's a diagnostic challenge often because the symptoms of C. difficile are so similar to the symptoms of an IBD flare, essentially patients presenting with diarrhea.

We should recognize that testing for C. difficile is critical in all patients with inflammatory bowel disease who have a change in their bowel frequency and are presenting with more diarrhea than at their baseline.

We've learned that in order to distinguish C. diff infection from colonizers, we really do need a 2-step strategy for diagnosis.

This involves, first, starting with a highly sensitive test like a PCR test for C. diff, following that up with a highly specific test for C. difficile infection with the EIA that can then help to distinguish those positive for PCR who may be colonizers from those who are also positive with the EIA who seemed to be infected because that is testing for the toxin.

Using this two-step strategy, we can try to sort out who really needs to be treated when it turns out that their C. diff is positive. Once you've identified somebody with C. difficile and who has underlying IBD, what we've learned is that initial treatment ought to be with vancomycin over metronidazole.

We have studies that have now shown us that outcomes are better when vancomycin is used upfront, particularly in hospitalized sicker patients where rates of colectomy, readmission, and hospital length of stay are all better with vancomycin than with metronidazole.

Another treatment option, particularly in outpatients but also potentially available for inpatients, would be fidaxomicin. Finally, we have a newer treatment available, the monoclonal antibody of bezlotoxumab, which can be given to patients who are suffering from recurrent C. difficile.

We also touched on the fact that FMT or manipulation of the microbiome with donor stool can be a very effective treatment for patients with C. difficile including those with inflammatory bowel disease, and we have increased reassuring evidence that this modality for treating C. diff is safe and highly effective in patients with inflammatory bowel disease.

Exciting on the horizon are newer therapies which can take FMT one step further by distilling it for those key ingredients, if you will, for what's in that donor stool that may be most highly effective in the form of a treatment-targeted therapy for patients with both C. difficile and inflammatory bowel disease.

Finally, we recognize that during this era of COVID, COVID itself can cause GI symptoms in patients with inflammatory bowel disease that yet one more thing to think about on the differential of someone with IBD presenting with a change in their GI symptoms.

Thinking about COVID in that scenario in addition to C. difficile but also recognizing that our access to FMT stool samples has been more limited due to the difficulties in testing of donor stool for COVID.

OpenBiome, a major source and supplier for FMT samples, has announced that it will begin resuming delivery of FMT samples for FMT to treat C. difficile beginning in early May 2021, which is very exciting news for those that rely on OpenBiome for the use of their fecal samples for treating of C. difficile.