Corey Cutler, MD: There are several risk factors for graft-vs-host disease, the most important of which is of course HLA [human leucocyte antigen] matching. The closer the donor and the recipient are in terms of HLA, the lower the risk of graft-vs-host disease [GVHD]. There are some other factors we can control. The age of both the donor and the recipient is an important risk factor. So is gender—both matched and using female donors are risk factors for graft-vs-host disease. Things like CMV [cytomegalovirus] serostatus traditionally have been considered risks but probably are less important these days. We also like to look at things like stem cell source. Peripheral blood stem cells have a slightly higher rate of graft-vs-host disease than bone marrow, which is slightly higher than umbilical cord blood. Some of these factors we can modify, so we can choose who the donor is going to be and what stem cell source. But some of these factors are not modifiable by us. We’re handed the donor and some of these factors, and sometimes we can’t avoid those problems.

Yi-Bin Chen, MD: When we speak about the overall incidence of acute graft-vs-host disease, we are generally referring to the percentage of patients who will develop overall grades 2 through 4 acute graft-vs-host disease as that’s the type that’s thought to be medically significant. It’s tough to answer that question because if you look at large studies, the incidence varies depending on a lot of clinical factors. If you summarize all the studies, you can find incidences anywhere from 10% all the way up to 80%. The general rule for a large population of patients undergoing all types of allogeneic transplant is an overall incidence of somewhere between 30% and 40% if you look at large series. In our own institution, we do review our outcomes on an annual basis. Over the last few years, our overall incidence of grades 2 through 4 of acute graft-vs-host disease in the first 6 months is right around 25% to 30%.

Zachariah DeFilipp, MD: When thinking about the incidence of acute GVHD, it’s important to remember that it’s dependent on several clinical factors, including the doughnut-type transplant as well as the GVHD prophylaxis regimen. There was a recent study published in the last year, BMT CTN 1203, that looked at 4 different types for GVHD prophylaxis regimens.

In that study, the incidence of grade 2 to 4 acute graft-vs-host disease, was in the range of 25% to about 35% for all 4 approaches. That’s similar to what we see at our institution at Massachusetts General Hospital, the incidence of acute graft-vs-host disease is also in the range of 25% to 30%.

Corey Cutler, MD: Acute GVHD presents with involvement in general of 3 organs only. We don’t quite understand why that is, but the skin, the gastrointestinal [GI] tract, and the liver are the 3 most commonly affected organs. The skin is present in 60% to 70% of cases of acute graft-vs-host disease, typically presenting with an erythematosus raised or maculopapular rash, often starting on the shoulder girdle, the forearms, and the upper body, and often working its way down. The gastrointestinal tract presents with perfuse watery diarrhea, abdominal cramping. Sometimes involvement of the upper GI tract presents with intractable nausea, anorexia, and things like that. The liver is the least commonly affected organ, presents typically with painless jaundice or hyperbilirubinemia, and patients typically do not recognize that early on. It’s mainly a laboratory finding unless it becomes severe and the patient is truly jaundiced.

Transcript Edited for Clarity