This 16 month old male child with severe combined
immunodeficiency received a haploidentical bone marrow transplant. Skin rash and diarrhea developed at
day 10 post transplant. Marked abdominal distension developed on day 16. Chest x-ray showed worsening
bilateral interstitial infiltrates. The patient died on day 21 post transplant.
The overall hepatic architecture is normal. The
portal tracts contain a relatively sparse inflammatory infiltrate that does not expand or fill portal
areas. The infiltrate is composed of large and small lymphocytes, with very few eosinophils and
neutrophils, and is centered around bile ducts. Mononuclear cells infiltrate the biliary epithelium. In
some ducts, the epithelial cells are sloughed; others show degenerative changes such as nuclear pyknosis,
cytoplasmic vacuolization, and irregular spacing of nuclei. The extent of bile duct injury is greater
than one might expect from the relatively sparse inflammatory infiltrate. No endothelialitis is seen.
The hepatic parenchyma is largely spared by the inflammatory process.
Click on each slide thumbnail image for an enlarged view:
Acute Graft-versus-host Disease
Interlobular bile ducts are the primary target in the liver in acute graft-versus-host disease. A mild lymphocytic infiltrate is often seen around the affected bile ducts, but inflammation is often minimal in relationship to the degree of bile duct injury. The bile duct epithelial cells in this example are sloughed and show degenerative changes. Lymphocytes may also infiltrate biliary epithelium.
Acute Graft-versus-host Disease
Acute rejection of the hepatic allograft and acute graft-versus-host disease after bone marrow
transplantation share morphologic features, as might be predicted, as both are the product of interaction
between an immune system and a liver that differ at the major histocompatibility complex. In a sense,
both are iatrogenic cholangiopathies. The bile ducts are the major target of injury in both processes,
and small bile ducts are more severely affected than larger ducts. The pathogenesis of bile duct injury
is not completely understood, but direct immunologic injury from invading lymphocytes and indirect damage
due to cytokine release are plausible mechanisms. In acute rejection, damage to the peribiliary vascular
plexus may result in ischemic injury to bile ducts, although this is less likely in GVHD. The presence
of immunologically active molecules on the cell surface of biliary epithelium is also a factor in these
post-transplant cholangiopathies. For instance, the major blood group antigens and Class I MHC antigens
are normally expressed on biliary epithelial cells. Class II MHC antigens, ICAM-1, CD51, and LFA-3 are
upregulated and expressed in the setting of inflammation and contribute to the immune-mediated injury
Acute rejection in the
liver is more common in younger patients and patients mismatched at the HLA-DR locus. Patients who
undergo liver transplantation because of alcoholic liver disease may have a lower incidence of acute
rejection .2 Acute rejection generally develops 5 to 21 days after transplantation and occurs in
~50% of patients. Very late presentations are often due to inadequate immunosuppression, either
from an attempt to decrease immunosuppression or due to poor patient compliance. Clinical presentation
is highly varied, ranging from no symptoms and normal liver tests in patients undergoing protocol
biopsies, to malaise and fever with elevated bilirubin, aminotransferases, and alkaline phosphatase .3
Acute graft-versus-host disease in bone marrow transplantation is more
likely to occur in patients receiving HLA-mismatched grafts. Histologic abnormalities of small bile
ducts resembling acute hepatic GVHD have also been described in recipients of autologous hematopoietic
cell transplants; the pathogenesis is unclear but may be related to failure to reconstitute and maintain
tolerance for self antigens after transplantation .4 Acute GVHD usually occurs 3 to 6 weeks after
transplantation and often presents first with skin involvement, followed by gastrointestinal
manifestations. Liver involvement is manifested by increased serum alkaline phosphatase,
hyperbilirubinemia with jaundice, and mild hepatomegaly. Approximately one-half of the 80% of bone
marrow transplantation patients with abnormal liver function tests will have acute hepatic GVHD. Because
most patients with hepatic involvement will also have skin and GI GVHD, liver biopsy is often not
obtained for diagnosis but to rule out other causes of hepatic dysfunction .5
The most helpful diagnostic features in acute rejection are the presence of a mixed portal inflammatory infiltrate with eosinophils, largely
sparing the hepatic parenchyma; infiltration and injury of bile ducts by lymphocytes; and
endothelialitis. The inflammatory infiltrate expands the portal areas and may focally spillover
into the adjacent parenchyma. Marked involvement of the hepatic parenchyma is not generally a feature of
acute rejection, although this may be seen in very severe cases. The infiltrate is composed of small
lymphocytes, large activated lymphocytes, macrophages, eosinophils, and varying numbers of neutrophils.
Plasma cells are rare, and immunophenotyping shows that most of the portal lymphocytes are T cells, with
both CD4+ and CD8+ cells represented. CD4+ cells mediate graft injury by releasing cytokines which
activate other effector cells, while CD8+ cells probably cause injury by direct cytopathic attack on
graft cells .3
Bile duct injury may be focal in mild acute rejection, or bile ducts may be obscured by the
inflammatory infiltrate and difficult to identify. The bile duct epithelium is infiltrated by
lymphocytes, and the biliary epithelial cells show cell swelling, cytoplasmic vacuolization, nuclear
crowding and reactive change such as prominent nucleoli and slight increase in the nuclear/cytoplasmic
ratio, and irregular spacing of nuclei. In very mild cases, only cuffing of bile ducts by inflammatory
cells, and slight reactive changes may be seen. In rejection treated with corticosteroids prior to
biopsy, infiltration of bile ducts by neutrophils may be prominent and may mimic biliary obstruction.
Endothelialitis, infiltration of venular endothelium by mononuclear inflammatory cells, is probably
overdiagnosed. In addition to the presence of lymphocytes in close proximity to vascular endothelium,
there should be evidence of endothelial cell injury such as endothelial cell enlargement and detachment.
Both portal veins and central veins may be affected. Occasionally central vein involvement is
particularly striking and may be associated with centrilobular hepatocyte necrosis and perivenular
hemorrhage. Portal changes typical of acute rejection are usually present in such cases. In pediatric
liver transplant recipients, isolated central venulitis occurs in up to 16%, generally appearing later
than portal rejection alone .6 Central venulitis may be seen in both acute and chronic rejection .7
Severe histologic endothelialitis may be associated with a poor response to antirejection therapy .8
Graft dysfunction associated with autoimmune features has been described in both children and adults
and may represent an unusual morphologic variant of acute rejection
Features include development of ANA and atypical anti-liver-kidney-microsomal antibodies, high aminotransferase levels
indicative of hepatocyte damage, and liver biopsy showing markedly active hepatitis with numerous plasma
cells. Subjects in one study showed higher prevalence of HLA-DR3 than other liver transplant recipients.
Portal inflammation is also a hallmark of acute graft-versus-host
disease, although it is less intense than in acute rejection. As in rejection, the inflammatory
infiltrate is predominantly mononuclear, and eosinophils and neutrophils are rare. The inflammatory
infiltrate centers about bile ducts, which show the diagnostic alterations in hepatic GVHD. Interlobular
bile ducts are distorted and angular, focally infiltrated by lymphocytes, and the epithelial cell nuclei
are irregularly spaced and pleomorphic. As in acute rejection, the lymphocytes infiltrating the bile
ducts in acute GVHD are T cells. The bile duct lumen may contain necrotic debris or sloughed epithelial
cells. Biopsies taken early in the course of hepatic GVHD (before Day 35 post-transplant) may not show
characteristic bile duct abnormalities, and may show only non-specific lobular changes such as spotty
hepatocyte necrosis. In my experience, endothelialitis is rarely if ever seen in acute hepatic GVHD, although a rate of 40%
has been reported. Cholestasis is a common finding in acute GVHD. Parenchymal necrosis may be seen, but is not specific.
Chronic Allograft Rejection
Chronic rejection in the hepatic allograft generally develops after
multiple episodes of acute rejection, or evolves from an episode of unresolved acute rejection. It may
rarely occur de novo in the patient who has never had clinical acute rejection. It is usually diagnosed
months to years following transplantation. Two major sites of attack are recognized in the liver:
interlobular bile ducts and hepatic arteries .3 The bile duct damage generally takes the form of
"vanishing bile duct syndrome", in which the bile duct loss is accompanied by only a mild
lymphoplasmacytic inflammatory infiltrate. Bile ductular proliferation is not seen, and the portal
inflammatory infiltrate subsides with loss of bile ducts, leaving empty-appearing portal tracts. Loss of
small hepatic artery branches occurs early, followed by bile duct loss .13 The foam cell arteriopathy
of chronic rejection is rarely seen on liver biopsy, as it preferentially involves the large arteries
near the hepatic hilum. This obliterative arteriopathy is characterized by the accumulation of foamy
histiocytes in the thickened intimal layer. The resulting ischemia may contribute to bile duct loss.
Centrilobular areas in both forms of chronic rejection show spotty hepatocyte necrosis, cholestasis, and
perivenular inflammation or fibrosis. Transient lobular hepatitis may also be a manifestation of chronic
rejection ,14 and the shift from a portal based inflammatory process towards lobular necroinflammatory
activity may represent the transition from acute to chronic rejection 15 .
Minimal diagnostic criteria are the presence of bile duct atrophy/pyknosis, affecting a majority of
the interlobular bile ducts; foam cell obliterative arteriopathy; or bile duct loss in over 50% of portal
tracts .16 Chronic rejection has been divided into early and late phases; such information from the
liver biopsy is used to guide patient management, as allografts with lesions of late chronic rejection
without inflammatory activity are unlikely to respond to additional immunosuppressive therapy. In early
chronic rejection, degenerative duct changes predominate and bile duct loss is seen in less than 50% of
portal tracts. Intimal or lumenal inflammation may be seen in central veins, and mild perivenular
fibrosis is seen in zone 3. Loss of portal tract arterioles is seen in less than 25% of portal tracts .16
In late chronic rejection, bile ducts are lost in over 50% of portal tracts. Inflammatory changes
are variable. Centrilobular fibrosis is more prominent than in early chronic rejection, and hepatic
arterioles are lost in over 25% of portal tracts .16 However, no histologic feature reliably predicts
response to immunosuppression or outcome .14 Differential diagnosis of chronic ductopenic rejection
includes bile duct stricture, particularly when the obstruction is partial; drug reaction; and
Chronic Graft-versus-host Disease
Chronic GVHD usually occurs after bouts of acute GVHD but may be
seen de novo in a minority of patients .17 The histopathology of chronic GVHD is not well delineated.
Like chronic rejection, it is characterized by bile duct distortion and loss and cholestasis. Hepatic
involvement occurs in about 90% of patients and the skin and oral mucosa are usually involved as well,
resulting in scleroderma-like changes and Sjogren's syndrome. Liver biopsy shows a sparse portal
mononuclear inflammatory infiltrate with severely distorted interlobular bile ducts. Canalicular
cholestasis is seen in the lobule. With loss of bile ducts and continued disease progression, changes of
chronic cholestasis may be seen and portal fibrosis followed by cirrhosis may develop. Unlike in chronic
rejection, arterial changes are not seen. An unusual pattern of chronic hepatic GVHD in which the
characteristic bile duct injury is combined with marked lobular hepatitis has recently been described .18
This pattern of injury was seen in patients receiving little or no immunosuppression after
allogeneic transplantation. Treatment with cyclosporine and prednisone resulted in progressive
improvement; those patients who were not treated with immunosuppressive therapy developed ductopenia and
progressive cholestasis .18 Since the differential diagnosis for chronic GVHD includes chronic viral
hepatitis, such cases may prove to be diagnostic dilemmas. The degree of portal inflammation, piecemeal
necrosis, and bile ductular proliferation are generally greater in viral hepatitis, whereas bile duct
injury and loss predominate in typical chronic GVHD.
Distinction between recurrent disease and acute rejection is often
challenging. Histologic recurrence of primary biliary cirrhosis is probably quite common, although
clinically significant disease is rare. A more pressing problem is the distinction of recurrent
hepatitis C from rejection. Recurrence of hepatitis C after transplantation is unavoidable, although not
all patients develop clinically significant hepatitis. Histologically evident recurrence begins with
spotty hepatocyte necrosis and lobular mononuclear infiltrates .19 A mononuclear inflammatory
infiltrate, generally mild, is present in the portal areas, and focal infiltration of bile ducts by
lymphocytes may be seen. As the disease progresses, the typical dense nodular aggregates of small
lymphocytes typical of hepatitis C infection may be seen in portal areas. Diagnostic problems occur
because of temporal and histologic overlap with acute rejection. One approach to this dilemma is to
compare portal and lobular changes. If lobular changes such as hepatocyte necrosis and lobular hepatitis
are more prominent than portal changes, then hepatitis C is favored. Acidophilic bodies may be a more
reliable indicator of recurrence than lobular inflammation .20 If the portal inflammatory infiltrate
includes activated lymphocytes and prominent eosinophils and there is little lobular activity, acute
rejection is favored.
GradingBanff Schema: Grading of Acute Hepatic Allograft Rejection 21
Several grading schemes for acute rejection have been developed. Most rely on the density
of the portal inflammatory infiltrate, the number of portal tracts involved, the extent of bile duct
injury and the extent of endothelialitis. One of the more recent schemes is the Banff Consensus Schema,
which relies upon a global assessment and generation of a rejection activity index by grading individual
features .21 At least two of the following three features are required for a histologic diagnosis of
acute rejection: mixed portal inflammatory infiltrate, predominantly mononuclear but also containing
neutrophils and eosinophils; bile duct damage or inflammation; and endothelialitis involving portal vein
branches or terminal hepatic venules. Once the diagnosis of acute rejection has been established in the
Banff schema, the grade is assigned based on the global assessment, which is largely based on the portal
inflammatory infiltrate. In addition, a rejection activity index may be generated and a total numerical
score based on the sum of the individual component scores assigned. In comparison to other grading
schemes, the Banff schema often results in up-grading of rejection .22
|Global Assessment ||Criteria|
|Indeterminate ||Portal inflammatory infiltrate that fails to meet criteria for diagnosis of acute rejection|
|Mild ||Rejection infiltrate in a minority of triads that is generally mild and confined to the portal area|
|Moderate ||Rejection infiltrate that expands most or all of the triads|
|Severe ||As above for moderate, with spillover into periportal areas and moderate to severe perivenular inflammation that extends into the hepatic parenchyma and is associated with perivenular hepatocyte necrosis|
Rejection Activity Index: Banff Schema 21
|Category ||Criteria ||Score|
|Portal Inflammation ||Mostly lymphocytic infiltrate involving but not expanding a minority of portal tracts ||1|
| ||Expansion of most or all of triads by mixed inflammatory infiltrate containing activated lymphocytes, neutrophils, and eosinophils ||2|
| ||Marked expansion of most or all triads by mixed infiltrate with numerous lymphoblasts and eosinophils with spillover into periportal parenchyma ||3|
|Bile Duct Inflammation/Damage ||A minority of bile ducts are cuffed and infiltrated by inflammatory cells; mild reactive changes such as increased N:C ratio ||1|
| ||Most or all duct infiltrated by inflammatory cells. More than an occasional duct shows degenerative changes such as nuclear pleomorphism, altered polarity, and cytoplasmic vacuolization ||2|
| ||As above for 2, with most or all of the ducts showing degenerative changes or focal lumenal disruption ||3|
|Venous Endothelial Inflammation ||Subendothelial lymphocytic infiltration involving some but not a majority of portal and/or hepatic venules ||1|
| ||Subendothelial infiltration involving most or all or portal and/or hepatic venules ||2|
| ||As above for 2, with moderate or severe perivenular inflammation that extends into the perivenular parenchyma and is associated with perivenular hepatocyte necrosis ||3|
Acute GVHD is graded clinically by assessing skin, liver, gastrointestinal involvement, and clinical
performance status .5 Histopathologic grading of acute hepatic GVHD provides little prognostic
information and is often not done, although various schemes have been proposed. Chronic GVHD is graded
as limited or extensive based on organ involvement or the presence of severe liver disease. The hepatic
involvement is regarded as limited if there is duct injury without piecemeal necrosis, fibrosis, or loss
of bile ducts. The designation of extensive chronic hepatic GVHD is reserved for liver biopsies with
these features .23
- Demetris AJ. Immune cholangitis: liver allograft rejection
and graft-versus-host disease. Mayo Clin Proc 73: 367-79, 1998.
- Bathgate AJ, Hynd P, Sommerville D, Hayes PC. The prediction
of acute cellular rejection in orthotopic liver transplantation. Liver Transplant Surg 5:475-9, 1999.
- Washington MK and Howell DN. The role of histopathology in
the evaluation of the liver transplant recipient. In Medical Care of the Liver Transplant Patient, 2
nd ed, Killenberg PC and Clavien P-A, eds. Malden , MA : Blackwell Science , 2001.
- Saunders MD, Shulman HM, Murakami CS, Chancey TR, Bensinger
WI, McDonald GB. Bile duct apoptosis and cholestasis resembling acute graft-versus-host disease after
autologous hematopoietic cell transplantation. Am J Surg Pathol 24:1004-8, 2000.
- McDonald GB, Shulman HM, Wolford JL, Spencer GD. Liver disease after human marrow transplantation.
Seminars in Liver Disease 7: 210-229, 1987.
- Krasinskas AM, Ruchelli ED, Rand , ED, Chittams JL, Furth ,
EE. Central venulitis in pediatric liver allografts. Hepatology. 33(5):1141-7, 2001 .
- Khettry U, Backer A, Ayata G, et al. Centrilobular
histopathologic changes in liver transplant biopsies. Hum Pathol 33:270-6, 2002.
- Andreu H, R imola A, Bruguera M, et al. Acute cellular
rejection in liver transplant recipients under cyclosporine immunosuppression: predictive factors of response to antirejection
therapy. Transplantation Proceed 34:243-4, 2002.
- Heneghan MA, Portmann BC, Norris SM, Williams R, et al. Graft
dysfunction mimicking autoimmune hepatitis following liver transplantation in adults. Hepatology
- Salcedo M, Vaquero J, Banaeres R, et al. Response to steroids in de novo
autoimmune hepatitis after liver transplantation. Hepatology 35:349-56, 2002.
- Shulman HM, Sharma P, Amos D, Fenster LF, McDonald GB. A coded histologic study of
hepatic graft-versus-host disease after human bone marrow transplantation. Hepatology 8:463-70, 1988.
- Snover DC, Weisdorf SA, Ramsay NK, McGlave P. Kersey JH. Hepatic graft versus host
disease: a study of the predictive value of liver biopsy in diagnosis. Hepatology 4: 123-30, 1984.
- Neil DAH, Hubscher SG. Histologic and biochemical changes during the evolution of chronic rejection of liver allografts. Hepatology 35:639-51, 2002.
- Sebagh M, Blakolmer K, Falissard B, et al. Accuracy of bile duct changes for the
diagnosis of chronic liver allograft rejection: reliability of the 1999 Banff schema.
- Gouw AS, van den H euvel MC, et al. The significance of parenchymal changes of
acute cellular rejection in predicting chronic liver graft rejection. Transplantation 73:243-7, 2002.
- An International Panel. Update of the international Banff schema for liver allograft
rejection: working recommendations for the histopathologic staging and reporting of chronic rejection.
Hepatology 31:792-9, 2000.
- Sullivan KM, Agura E, Anasetti C, et al. Chronic graft-versus-host disease and other
late complications of bone marrow transplantation. Semin Hematology 28:250-9, 1991.
- Stasser IS, Shulman HM, Flowers ME, Reddy R, et al. Chronic graft-versus-host
disease of the liver: presentation as acute hepatitis. Hepatology 32:1265-71, 2000.
- Ferrell LD, Wright TL, Roberts J, Ascher N, Lake J. Hepatitis C viral infection in
liver transplant recipients. Hepatology 16:865-76, 1992.
- Saxena R, Crawford JM, Navarro VJ, Friedman AL, Robert ME. Reliability of acidophil
bodies as a marker of recurrent hepatitis C infection after orthotopic liver transplantation. Modern
Pathology 12:166A, 1999.
- Demetris AJ, Batts KP, Dhillon AP, Ferrell L, et al. Banff schema for grading liver
allograft rejection: an international consensus document. Hepatology: 25:658-63, 1997.
- Ormonde DG, de Boer WB, Kierath A, Bell R, Shilkin KB, House AK, Jeffrey GP, Reed WD.
Banff schema for grading liver allograft rejection: utility in clinical practice. Liver Transplantation
and Surgery 5: 261-8, 1999.
- Snover , DC . Biopsy Diagnosis of Liver Disease. Baltimore : Williams &
Wilkins, 1992: 228-9.