Zachariah DeFilipp, MD: It’s important to remember that graft-vs-host disease [GVHD] is a clinical diagnosis. Sometimes we do perform biopsies that can be supportive of that diagnosis, but they’re also very important in helping to rule out other diagnoses, specifically, CMV [cytomegalovirus] infections.

For example, if a patient presents with lower GI [gastrointestinal] GVHD than is suspected, we often will perform an endoscopy and get biopsies. These biopsies may be supportive of the GVHD diagnosis if they show apoptosis along the GI tract. But more important, stains can be done to help rule out CMV, which will affect our treatment moving forward.

Biopsies can also be very helpful for patients who have suspected liver GVHD because the differential diagnosis of liver inflammation early after transplant is wide.

Corey Cutler, MD: Acute graft-vs-host disease is largely a clinical diagnosis. We do not necessarily need to do biopsies of the affected organs to confirm the diagnosis. Rather, we do biopsies of the affected organs to exclude other diagnoses. For example, the skin, if we do a biopsy, it’s to exclude a drug rash or another type of exanthem. If we do a biopsy of the gastrointestinal tract via colonoscopy or sigmoidoscopy, it’s to exclude things like CMV or a C diff [Clostridium difficile] infection. When we do a biopsy of the liver, which is done the least frequently, it’s done to exclude drug toxicity or veno-occlusive disease. That being said, more often than not, these are clinical diagnoses with no diagnostic tests that we can perform.

Classifying acute GVHD is important for us. By everyone using a common methodology, it allows us to enroll patients in clinical trials and really speak to one another about efficacy of therapies. Each organ is staged individually, so the skin is given a stage of involvement based on the degree of body surface area involved. The gastrointestinal tract is given an individual organ stage, based either on the volume of diarrhea or more recently based on the number of bowel movements per day. And the liver is given an individual organ stage based on the rise in the serum bilirubin. Once you have an individual organ stage, you can go ahead and group those individual organs into an overall grade. Traditionally, we’ve used the modified Glucksberg grading system of graft-vs-host disease. Alternatively, the CIBMTR [Center for International Blood and Marrow Transplant Research] has an organ GVHD grading system. Most recently, MaGIC [Malignant Germ Cell International Consortium] has come up with a slight reorganization, and many institutions are using the MaGIC criteria, particularly in clinical trials.

Transcript Edited for Clarity