Graft-versus-host disease (GVHD) is a condition that can occur after allogeneic stem cell transplantation. The word “graft” refers to the donor’s cells, and the “host” is the patient. The 3 major target organs of acute and chronic GVHD include the skin, liver, and gut (or gastrointestinal [GI] mucosa). After the skin, the GI tract is the second most affected organ in acute GVHD and often has the most severe symptoms.
Gut GVHD Pathobiology
The pathobiology of gut GVHD is a complicated pathway involving different cells, molecules, and signals, that causes normal bowel disruption. Tissue damage begins with the conditioning regimen (chemotherapy and total body irradiation) to trigger immune activation and imbalance of the intestinal microbiota.
- Immune activation. Tissue damage causes the release of several inflammatory cytokines, including interleukin-1 (IL-1), tumor necrosis factor-α (TNF-α), interleukin-12 (IL-12), transforming growth factor-β (TGF-β), and others. These cytokines activate antigen-presenting cells, or APCs. The patient’s APCs present to the donor graft T cells to kill off healthy cells that line the patient’s intestines. An inflammatory cascade of events causes tissue destruction.
- Gut microbiome. The breakdown of the mucosal barrier from the conditioning regimen compromises the body’s defense against infection by creating an entry point for germs, also called microbes. Gram-positive bacteria, such as Enterococcus, affect the intestinal microenvironment, causing more infection and worse GVHD. These microbes invade the underlying submucosa and eventually reach the bloodstream, leading to sepsis.
Gut GVHD is typically a clinical diagnosis with standardized assessments. However, a biopsy with an endoscopy, colonoscopy, or sigmoidoscopy can support that diagnosis by ruling out other causes, specifically cytomegalovirus (CMV).
Assessing for Gut GVHD
GVHD can affect either the upper or lower GI tract or both locations. Therefore, oncology nurses can monitor for symptoms that may suggest the site of the GVHD.
| Lower GI | Upper GI |
|
|
Diarrhea caused by acute gut GVHD is often very distinct with a green mucoid, watery appearance and may contain exfoliated cells and tissue shreds. It can have visible or non-visible blood. Patients can also experience weight loss, and infants and children can experience failure to thrive.
In addition to diarrhea and weight loss, some patients may slowly develop debilitating tissue injury. Since chronic GVHD mimics an autoimmune disorder, patients can have changes in the esophagus, such as web, strictures, or stenosis. Oncology nurses must assess patients complaining of “food getting stuck” or “difficulty swallowing.”
Staging of Gut GVHD
Oncology nurses play a critical role in helping to count the episodes of diarrhea every 24 hours and accurately measuring stool volume. For acute gut GVHD, the modified Glucksberg scale measures volume, and the Mount Sinai Acute GVHD International Consortium (MAGIC) modified the criteria to include counting episodes of diarrhea.
| Adult Staging of Gut GVHD | ||
| Stage | Lower GI
(Diarrhea) |
Upper GI
(Nausea/Vomiting) |
| 0 | None or <500 mL/day or
<3 episodes/day |
No persistent nausea or vomiting |
| 1 | >500 but <1000 mL/day or
3-4 episodes/day |
Persistent nausea or vomiting |
| 2 | >1000 but <1500 mL/day or
5-7 episodes/day |
– |
| 3 | >1500 mL/day or
>7 episodes/day |
– |
| 4 | Severe abdominal pain, with or without ileus | – |
Measuring stool volume can be challenging because urine may contaminate the stool collection or incontinence may contribute to inaccurate measurements. Therefore, oncology nurses must educate patients on the importance of measuring and recording intake and output as best they can with diarrhea. In addition, patients need to be instructed to report any other symptoms, such as nausea, vomiting, or pain that often feels like cramping.
Oncology nursing care of patients with gut GVHD includes obtaining cultures, ensuring intake and output accuracy, monitoring fluid and electrolyte imbalances, coordinating with the dietitian on nutritional needs, and managing treatment-related side effects. In addition, nurses can offer basic suggestions like using baby wipes instead of toilet tissue to prevent rectal skin breakdown.
Oncology nurses often associate diarrhea with acute gut GVHD, but they must remember that the gut is also a target for chronic GVHD. Early recognition and prompt intervention can improve patients’ outcomes and prevent life-threatening complications of gut GVHD. Of all the GVHD target organs, gut GVHD can be the most severe, leading to life-threatening infections and multisystem organ failure.
References
Hematopoietic Stem Cell Transplantation: A Manual for Nursing Practice
