Acute graft versus host disease in the liver is a serious complication that can occur after a stem cell or bone marrow transplant, when immune cells from the donor attack the recipient’s liver tissue, causing inflammation and potential damage to this vital organ.

What Is Acute Graft Versus Host Disease in the Liver?

Acute graft versus host disease, or acute GVHD, happens when the body faces an unusual challenge after receiving donor stem cells. Following an allogeneic transplant (a procedure where stem cells come from another person), the immune cells from the donated tissue may not recognize the recipient’s body as friendly. Instead, these donor cells mistakenly see the recipient’s organs and tissues as foreign invaders and launch an attack against them.^[1]

The liver is one of the main organs that can be affected by acute GVHD. When this occurs, donor immune cells target liver tissue, particularly the small bile ducts and liver cells themselves. This immune attack typically happens within the first 100 days after transplant, though it can occasionally appear later. The condition causes inflammation and damage that interferes with the liver’s normal functions.^[1][3]

Acute GVHD of the liver rarely occurs in isolation. Most patients who develop liver GVHD also experience symptoms in other organs, particularly the skin and gastrointestinal tract. In fact, among transplant recipients who develop GVHD affecting multiple organs, the liver is involved in about 8% of cases. It’s quite uncommon for acute GVHD to attack only the liver without affecting other parts of the body.^[3]

Understanding the Causes

The fundamental cause of acute graft versus host disease stems from the complex biology of transplantation. During an allogeneic stem cell transplant, a patient receives blood-forming cells from a donor to replace their own damaged or diseased cells. This type of transplant is often necessary for people with serious blood cancers like leukemia or lymphoma, or other conditions affecting the bone marrow.^[2]

Every person’s cells carry special proteins on their surface called human leukocyte antigens, or HLA. These proteins act like identification tags that help the immune system distinguish between the body’s own cells and foreign invaders. When donor stem cells are transplanted into a recipient, the immune cells within that graft examine the recipient’s tissues. If there are differences in HLA markers between donor and recipient, the donor’s immune cells may perceive the recipient’s organs as threats and begin attacking them.^[2]

The liver becomes a target in this process because it contains tissues that the donor immune cells encounter as they circulate through the body. The small bile ducts within the liver and the liver cells themselves bear the recipient’s HLA markers, making them potential targets for the donor’s immune response. When these immune cells attack, they cause inflammation and damage to the liver’s delicate structures.^[3]

Who Is at Risk?

Several factors can increase a person’s likelihood of developing acute graft versus host disease after a stem cell transplant. Understanding these risk factors helps medical teams prepare and monitor patients more carefully during the critical post-transplant period.

The degree of HLA matching between donor and recipient plays a major role in GVHD risk. When donor and recipient are siblings or other close relatives with closely matched HLA types, the risk of acute GVHD ranges from about 35% to 45%. However, when the transplant involves an unrelated donor with less perfect matching, the risk increases substantially to between 60% and 80%.^[6]

The type of donor cells used also influences risk. Transplants using peripheral blood stem cells (cells collected from circulating blood) tend to carry more lymphocytes than those using bone marrow cells. Since lymphocytes are the immune cells responsible for attacking recipient tissues, their higher numbers in peripheral blood transplants can increase GVHD risk. Additionally, receiving stem cells from a female donor appears to slightly elevate the risk of developing GVHD.^[11]

Patients who receive total body irradiation as part of their pre-transplant conditioning regimen face increased odds of developing acute GVHD. This intensive radiation treatment, while necessary to prepare the body for new stem cells, can create conditions that make GVHD more likely to occur.^[11]

Other factors that may influence risk include the patient’s age, the underlying disease being treated, and the specific medications used to prevent GVHD. Younger patients generally have lower rates of severe GVHD compared to older adults. The intensity of the conditioning regimen and the timing of immune-suppressing medications also play important roles in determining who will develop this complication.^[1]

Recognizing the Symptoms

Acute GVHD of the liver often produces symptoms that can be subtle or easy to miss in the early stages. Many patients may not feel any symptoms at all when liver GVHD first begins. The condition is frequently discovered during routine blood tests that show abnormal liver function rather than through complaints from the patient.^[18]

The most characteristic sign of liver GVHD is jaundice, a yellowing of the skin and the whites of the eyes. This discoloration occurs because the damaged liver cannot properly process a substance called bilirubin, which then builds up in the body and causes the yellow tint. Jaundice may start gradually and become more noticeable over several days.^[2][6]

Some patients notice that their urine becomes darker than usual, appearing brown or tea-colored. This happens because excess bilirubin is being eliminated through the kidneys. The stool may become lighter in color for the same reason, as less bilirubin reaches the intestines to give stool its normal brown color.^[6]

Patients might experience discomfort or pain in the upper right portion of the abdomen, where the liver is located. This pain can range from a dull ache to a more intense sensation. Some people describe feeling fullness or pressure in this area as the liver becomes inflamed and potentially enlarged.^[2]

Because acute GVHD typically affects multiple organs simultaneously, patients with liver involvement often experience symptoms in other body systems as well. These may include skin rashes that resemble sunburn, particularly on the palms, soles, ears, and neck. Gastrointestinal symptoms like nausea, vomiting, diarrhea, and abdominal cramping frequently accompany liver GVHD. The combination of symptoms affecting different organs helps doctors recognize that GVHD may be responsible for the patient’s problems.^[2][14]

How the Disease Is Diagnosed

Diagnosing acute GVHD of the liver requires careful detective work by medical professionals. The process combines laboratory tests, clinical observations, and sometimes tissue samples to reach an accurate conclusion. This careful approach is necessary because many other conditions can cause similar symptoms in transplant recipients.^[3]

Blood tests form the foundation of diagnosis. Doctors regularly check liver function tests, which measure levels of certain enzymes and proteins that indicate how well the liver is working. In liver GVHD, these tests typically show elevated levels of alkaline phosphatase and bilirubin, substances that increase when bile ducts are damaged or blocked. The total bilirubin level helps determine the severity of liver involvement and is used to stage the disease.^[3][14]

The timing of symptoms provides important clues. Classic acute GVHD typically appears within the first 100 days after transplant, though it can occur later. When liver problems develop during this critical window, and especially when skin or gastrointestinal symptoms accompany them, doctors have strong reason to suspect GVHD.^[1]

In some cases, doctors may perform a liver biopsy, a procedure where a small sample of liver tissue is removed and examined under a microscope. This can show characteristic changes in the small bile ducts, including damage to the cells lining these ducts and inflammation in surrounding areas. However, liver biopsies carry risks in transplant patients, who may have low blood cell counts that increase bleeding risk. Therefore, biopsies are not always performed, and doctors often diagnose liver GVHD based on clinical signs and blood test patterns.^[3]

The diagnostic challenge lies in distinguishing liver GVHD from other problems that commonly affect transplant recipients. Viral infections, particularly cytomegalovirus and hepatitis viruses, can damage the liver in similar ways. Many medications used during transplant, including antibiotics and immunosuppressive drugs, can cause drug-induced liver injury that mimics GVHD. Another complication called veno-occlusive disease, where small veins in the liver become blocked, can also cause jaundice and abnormal liver tests.^[3]

To solve these diagnostic puzzles, doctors consider the complete clinical picture. They review all medications the patient is taking, check for evidence of infections through blood and urine tests, and look for characteristic patterns in how the liver function tests change over time. The presence of GVHD in other organs, particularly the skin and gastrointestinal tract, strongly supports a diagnosis of liver GVHD since isolated liver involvement is uncommon.^[14]

Preventing Acute GVHD of the Liver

Prevention of acute GVHD begins even before the transplant takes place. Medical teams work diligently to reduce the likelihood that donor immune cells will attack the recipient’s body. The cornerstone of prevention involves giving medications that suppress the immune system, making it less likely that donor cells will launch an aggressive response.^[9]

The most widely used preventive approach combines two medications: a drug called cyclosporine or tacrolimus, taken for approximately six months after transplant, along with short courses of methotrexate given in the days immediately following the transplant. Cyclosporine and tacrolimus are calcineurin inhibitors, medicines that calm down the immune system by blocking certain signals that would otherwise activate immune cells. Doctors carefully monitor blood levels of these drugs to ensure they remain high enough to prevent GVHD but not so high as to cause toxic side effects.^[9]

Some transplant centers use additional strategies to reduce GVHD risk. One approach involves removing certain immune cells called T-cells from the donor’s stem cells before transplantation. Since T-cells are the main culprits in causing GVHD, reducing their numbers can lower the risk. Another prevention method uses a medication called antithymocyte globulin, or ATG, given before the transplant. This powerful drug significantly reduces the risk of severe acute GVHD, though it may also increase the chance of infections because it weakens the immune system more broadly.^[9]

Newer prevention strategies continue to emerge from ongoing research. Some centers experiment with different combinations of immunosuppressive drugs or use medicines that specifically target certain immune pathways. The goal is always to find the right balance between preventing GVHD and maintaining enough immune function to fight infections and help the graft succeed.^[9]

Matching donors and recipients as closely as possible based on HLA types remains one of the most effective prevention strategies. When siblings or other relatives share very similar HLA markers, the risk of severe GVHD decreases substantially. For patients without matched family donors, searching donor registries for unrelated individuals with the closest possible HLA match can improve outcomes.^[6]

How the Liver Changes During Acute GVHD

Understanding what happens inside the liver during acute GVHD helps explain why this condition causes the symptoms and complications that patients experience. The disease process involves a series of changes at the microscopic level that gradually impair the liver’s ability to function normally.

The attack begins when donor immune cells, particularly T-lymphocytes, recognize the recipient’s liver tissue as foreign. These immune cells migrate to the liver and begin releasing substances called cytokines, which are chemical messengers that trigger inflammation. This inflammatory response is the immune system’s way of trying to eliminate what it perceives as a threat, but in this case, the “threat” is actually the recipient’s own healthy liver tissue.^[1]

The small bile ducts within the liver become primary targets of this immune attack. These tiny tubes, which normally carry bile from the liver to the intestines, have cells lining their walls that bear the recipient’s HLA markers. When donor immune cells attack these bile duct epithelial cells, the cells become damaged and may die. This damage disrupts the normal flow of bile, a substance the liver produces to help digest fats and eliminate certain waste products.^[3]

As bile duct cells are destroyed, bile cannot flow properly through the liver’s intricate network of channels. Bile components, particularly bilirubin, begin to accumulate in the liver and eventually spill into the bloodstream. This buildup of bilirubin in the blood causes the characteristic yellow discoloration of jaundice. The damaged bile ducts may also become inflamed and swollen, further obstructing bile flow.^[3]

The liver cells themselves, called hepatocytes, can also suffer damage during acute GVHD, though bile duct injury is usually more prominent. When hepatocytes are attacked by immune cells or affected by the surrounding inflammation, they cannot perform their normal functions as efficiently. These cells are responsible for processing nutrients, making proteins, clearing toxins from the blood, and producing bile. As more hepatocytes become damaged, the liver’s overall function declines.^[3]

Under a microscope, pathologists examining liver tissue from patients with acute GVHD see specific patterns of damage. The bile ducts show signs of injury, with damaged or dying cells visible in their walls. Immune cells infiltrate the areas around the bile ducts, creating patches of inflammation. In some cases, entire small bile ducts may disappear, a condition called duct loss or vanishing bile duct syndrome. When many bile ducts are lost, the liver’s ability to process and eliminate bile becomes severely compromised.^[3]

The severity of these microscopic changes corresponds to the clinical stage of liver GVHD. Mild cases show limited bile duct damage with minimal inflammation, while severe cases demonstrate widespread destruction of bile ducts, extensive inflammation, and significant impairment of liver architecture. The extent of these changes influences how doctors stage the disease and determines the intensity of treatment needed.^[14]

These pathological changes explain why patients develop elevated liver enzymes in blood tests. Enzymes like alkaline phosphatase leak into the bloodstream when bile duct cells are damaged. Bilirubin levels rise because damaged bile ducts cannot transport it properly. Other liver function tests may show decreased production of proteins or impaired ability to clear certain substances, reflecting the liver’s reduced capacity to perform its normal work.^[14]