Massive haemorrhagic necrosis of the liver after liver transplantation

Early Graft Loss With Suspected Seventh-Day Syndrome Following Pediatric Liver Transplantation

INTRODUCTION

Allograft dysfunction within the first week posttransplant is an uncommon but known complication following liver transplantation. Seventh-Day Syndrome (7DS) is a rare complication of allograft dysfunction following liver transplantation characterized by the rapid clinical deterioration of a formerly well-functioning allograft within the first week posttransplant. The etiology of 7DS is unknown, and treatment options remain limited. While cases of graft survival have been reported, the risk of mortality remains exceedingly high without urgent retransplantation.

METHODS

Patient data was retrospectively analyzed and a literature review performed.

RESULTS

We present a unique case of split liver transplantation into two pediatric recipients in which one recipient developed rapidly progressive graft failure approximately 1 week postoperatively requiring urgent retransplantation while the other recipient had an unremarkable postoperative course. Upon clinical manifestation of progressive graft failure, the patient was treated with thymoglobulin, rituximab, intravenous immunoglobulin, and plasmapheresis. Despite this, the patient's clinical status continued to decline and she underwent retransplantation 11 days following her initial liver transplant.

CONCLUSION

Seventh-Day Syndrome is a rare complication following liver transplantation that is associated with a high risk of morbidity and mortality. Our case adds to the limited literature on 7DS in children and is the first to report a comparative posttransplant clinical course in two recipients who received split grafts from the same donor.

Evidence for Alloimmune Sinusoidal Injury in De Novo Nodular Regenerative Hyperplasia After Liver Transplantation

Posttransplant nodular regenerative hyperplasia (NRH) mostly remains unexplained. Microvascular injury due to antibody-mediated rejection (AMR) is suspected, but lack of donor specific antibody (DSA) testing makes it difficult to prove. Centered around a 1-year period of routine DSA testing, concomitant protocol, and indicated posttransplant liver biopsies (LB), recipients with NRH (n = 18) were compared with a matched control group (n = 36). All index, previous, and subsequent LB were reviewed. Both groups were similar in terms of demographics, timing of index LB, and DSA. In the index LB, the NRH group had higher sinusoidal C4d positivity (p = 0.029) and perisinusoidal fibrosis (p = 0.034), both independently associated with NRH (p = 0.038 and 0.050, respectively). Features of "possible" chronic AMR were detected in 28.5% of the NRH group without a known cause and 0% of the control group (p = 0.009). The NRH group had more preceding indicated LB with increased incidence of rejection and biliary obstruction pattern. In the follow-up histology, overall, sinusoidal and portal C4d positivity, sinusoidal microvasculitis, and perisinusoidal fibrosis were also higher (all p < 0.050). In conclusion, we provide evidence towards the hypothesis that some cases of posttransplant NRH are related to preceding active and persistent AMR. Large multicenter studies with protocol DSA testing are required to confirm.

Seventh Day Syndrome Revisited: Early Recognition of the Clinical Syndrome and an Evolving Understanding of Its Etiology

Background

Unexplained acute failure of an initially functioning liver graft early post-transplant has been described as Seventh-Day Syndrome (7DS). The aims of this study were to describe the clinical syndrome in detail based on an institutional case series and literature review.

Methods

A retrospective review of adult patients that underwent deceased donor liver transplantation at our institution between January 2010 and 2020 was performed to identify patients that developed 7DS. Relevant clinical variables were obtained from medical records. Existing cases in the literature were identified by a systematic literature search according to PRISMA guidelines. Pooled analysis was used to describe the incidence, retransplantation, and mortality rate. Histological findings from institutional and published literature cases were collected and appraised.

Results

Six of 1,907 liver transplantations at our institution (0.3%) developed 7DS. Seven case series, describing 42 patients with 7DS, and two single case reports were identified from literature review. Pooled incidence of 7DS was low (2.1%, 95%CI: 0.7-3.9%) and associated with high mortality (74.8%, 95%CI: 49.2-94.6%). Retransplantation was performed in 23/42 (55%) patients and 4/23 (17%) survived. Review of histology showed frequent intrahepatic thrombi and arteritis. Rejection, with features of potential antibody mediated rejection, often preceded or accompanied progressive zonal coagulative necrosis and hemorrhage.

Conclusions

7DS is a rare clinical syndrome after liver transplantation and associated with high mortality. Antibody-mediated rejection, as suggested in early reports, is likely to be involved in the pathogenesis. Early recognition would allow rapid clinical diagnostics and expedited decisions, such as treatment of AMR if diagnosed or early retransplantation.

Successful management to prevent early graft loss due to Seventh-day Syndrome after liver retransplantation: A case report and literature review

Graft loss characterized by sudden deterioration after initial favorable recovery of the allograft function within the first week after liver transplantation was reported as "seventh-day syndrome." The outcome of seventh-day syndrome is extremely poor, and its etiology and management are not still established. We herein reported a seventh-day syndrome case who was successfully managed by immediate desensitization after liver retransplantation and reviewed by English literature. A 19-year-old woman who had underwent the first liver transplantation when she was 2-year-old. She developed graft failure due to chronic rejection and was on the waiting list for retransplantation. An evaluation of panel-reactive antibody showed high positivity, but there were no preformed donor-specific antibodies. Plasma exchange was performed one-time just before retransplantation and the mean fluorescence intensity significantly decreased. The second liver was successfully transplanted, and post-operative course was uneventful. However, on post-operative day 5, her body temperature elevated and thereafter, her liver enzymes dramatically elevated. We immediately started a desensitization consisted of plasma exchange, intravenous immunoglobulin, and anti-CD20 antibody. The peak level of AST and ALT was 5799 IU/L and 3960 IU/L, respectively. The pathological findings of liver biopsy revealed some central venous endotheliitis and massive centrilobular hemorrhagic hepatocellular necrosis. These findings were not typical for antibody-mediated rejection, but the desensitization was effective and liver graft was successfully rescued. The only way to prevent early graft loss due to seventh-day syndrome is thought to be an immediate decision to start intensive desensitization.

Antibody-Mediated Rejection After Liver Transplant

Antibody-mediated rejection (AMR) in liver transplants is a field in its infancy compared with its allograft cohorts of the kidney and lung. Acute AMR is diagnosed based on specific clinical and histopathologic criteria: serum donor specific antibodies, C4d staining, histopathologic findings on liver biopsy, and exclusion of other entities. In contrast, the histologic features of chronic AMR are not as specific and it is a more challenging diagnosis to make. Treatments of acute and chronic AMR include some combination of steroids, immune-modulating agents, intravenous immunoglobulin, plasmapheresis, and proteasome inhibitors.

From immunosuppression to tolerance

The past three decades have seen liver transplantation becoming a major therapeutic approach in the management of end-stage liver diseases. This is due to the dramatic improvement in survival after liver transplantation as a consequence of the improvement of surgical and anaesthetic techniques, of post-transplant medico-surgical management and of prevention of disease recurrence and other post-transplant complications. Improved use of post-transplant immunosuppression to prevent acute and chronic rejection is a major factor in these improved results. The liver has been shown to be more tolerogenic than other organs, and matching of donor and recipients is mainly limited to ABO blood group compatibility. However, long-term immunosuppression is required to avoid severe acute and chronic rejection and graft loss. With the current immunosuppression protocols, the risk of acute rejection requiring additional therapy is 10-40% and the risk of chronic rejection is below 5%. However, the development of histological lesions in the graft in long-term survivors suggest atypical forms of graft rejection may develop as a consequence of under-immunosuppression. The backbone of immunosuppression remains calcineurin inhibitors (CNI) mostly in association with steroids in the short-term and mycophenolate mofetil or mTOR inhibitors (everolimus). The occurrence of post-transplant complications related to the immunosuppressive therapy has led to the development of new protocols aimed at protecting renal function and preventing the development of de novo cancer and of dysmetabolic syndrome. However, there is no new class of immunosuppressive drugs in the pipeline able to replace current protocols in the near future. The aim of a full immune tolerance of the graft is rarely achieved since only 20% of selected patients can be weaned successfully off immunosuppression. In the future, immunosuppression will probably be more case oriented aiming to protect the graft from rejection and at reducing the risk of disease recurrence and complications related to immunosuppressive therapy. Such approaches will include strategies aiming to promote stable long-term immunological tolerance of the liver graft.

Newly defined clinical features and treatment experience of seventh day syndrome following living donor liver transplantation

AIM

The aim of this study was to describe a unique Seventh-Day Syndrome (7DS) in our liver transplantation center.

METHODS

We performed a retrospective analysis of 244 cases of adult living donor liver transplantations (LDLT) performed in our liver transplantation center from January 1995 to January 2009.

RESULTS

Since 2005, we identified 8 cases of 7DS. Previously reported features for 7DS include a rapid deterioration of liver function followed by renal failure and a sudden peak in liver enzyme levels around day 7. In addition, the following attributes have been observed in our patients: (1) all recipients were males while the donors included both genders; (2) most patients showed increased levels of irritability; (3) color Doppler revealed reduced blood flow or bidirectional blood flow in the portal vein; (4) coagulation necrosis was observed with disruption of lobular architecture and increased expression of death receptor Fas in all examined patients; (5) after onset, a steroid pulse with or without OKT3 therapy showed minimal effect; (6) a abrupt increase in liver enzymes was noted 1-2 days after intravenous (IV) methylprednisolone was switched to oral immunosuppressants; and (7) extension of IV methylprednisolone treatment delayed the occurrence from 8 to 11 days postoperatively.

CONCLUSIONS

7DS is a distinct entity associated with early graft dysfunction, which is associated with a high rate of mortality and need for retransplantation. Coagulation necrosis and Fas receptor activation may be implicated in the occurrence of 7DS. Our study supported the hypothesis that 7DS may be associated with an undefined immune response. Our experience extending IV methylprednisolone treatment seeking to delay occurrence and reduce mortality provided a possible therapeutic approach for 7DS.

Tacrolimus monotherapy in liver transplantation: one-year results of a prospective, randomized, double-blind, placebo-controlled study

BACKGROUND

Minimal immunosuppression (IS) is desirable in organ transplantation to reduce side effects and to promote the process of tolerance induction.

MATERIAL AND METHODS

Between February 2000 and September 2004, 156 adults (>15 years old) receiving a primary liver graft were enrolled in a prospective, randomized, double-blind, placebo-controlled, investigator-driven single-center study comparing tacrolimus (TAC)-placebo (PL) and TAC-low-dose, short-term (64 days) steroid (ST) IS. There were no exclusion criteria at moment of randomization. All patients had a 12-month follow-up (range, 12-84).

RESULTS

Three- and 12-month patient survival rates were 93.6% and 87.2% in the TAC-PL group and 98.7% and 94.7% in TAC-ST group (P = 0.096 and P = 0.093, respectively). Three- and 12-month graft survival rates were 92.3% and 85.9% versus 97.4% and 92.3% (P = 0.14 and 0.13, respectively). By 3 and 12 months, rejection treatment had been given in 20.5% (16 pts) and 23% (18 pts) of TAC-PL patients and in 12.7% (10 pts) and 20.5% (16 pts) of TAC-ST patients (P = 0.20 and 0.54). Corticosteroid-resistant rejection (CRR) at 3 and 12 months was recorded in 12.8% (10 pts) of TAC-PL patients and 3.8% (3 pts) of TAC-ST patients (P = 0.04). When considering the 145 patients transplanted without artificial organ support (n = 145), CRR at 3 and 12 months was recorded in 8.8% (6/68 pts) of TAC-PL patients and in 3.9% (3/77 pts) of TAC-ST patients (P = 0.22). Vanishing bile duct syndrome was diagnosed in 1 (1.2%) TAC-PL patient and 4 (5.1%) TAC-ST patients (P = 0.17). By 1 year, 78.2% (61/78) of TAC-PL patients and 82% (64/78) of TAC-ST patients were on TAC monotherapy (P = 0.54). When considering 67 TAC-PL and 74 TAC-ST survivors, rates of monotherapy were 91% (61 pts) and 86.5% (64 pts) (P = 0.39). At 1 year, 62.5% (42 pts) of TAC-PL survivors and 64.9% (48 pts) of TAC-ST survivors were on low-dosage (<6 ng/mL) TAC monotherapy (P 0.79).

CONCLUSION

TAC monotherapy can be achieved safely without compromising graft nor patient survival in a primary, even unselected, adult liver transplant population. The higher incidence of early CRR in the TAC-PL group related to the significantly higher number of patients transplanted while being on artificial organ support. In such condition, this monodrug immunosuppressive strategy needs to be adapted. TAC monotherapy strategy should lay the basis for further large scale minimization studies in liver transplantation.

C4d immunopositivity is uncommon in ABO-compatible liver allografts, but correlates partially with lymphocytotoxic antibody status

AIMS

To determine whether C4d immunopositivity helps recognition of humoral rejection in dysfunctional liver allografts.

METHODS AND RESULTS

C4d immunopositivity was retrospectively evaluated in liver allografts. There were three staining patterns: portal venular plexus, sinusoidal and hepatocellular. The latter was related to ischaemic necrosis and not scored as positive. C4d immunopositivity was not encountered in 10 preperfusion or 15 consecutive early protocol biopsies. However, three of 12 early protocol biopsy specimens from crossmatch-positive patients were C4d+, two showing repeated positivity on at least one further biopsy specimen, while others remained negative. C4d was also positive in 2/16 early moderate acute cellular rejections, 3/14 cases of centrilobular necroinflammation, 3/11 biliary obstructions, 3/13 chronic rejections and 1/10 primary non-functional allografts.

CONCLUSION

C4d immunopositivity is uncommon in liver allografts. There is a weak positive correlation with a positive lymphocytotoxic crossmatch and some patterns of allograft dysfunction. The morphological associations resemble those reported in lymphocytotoxic crossmatch-positive patients, plus occasional sinusoidal and hepatocellular injury. Although the practical utility of C4d immunohistochemistry seems limited, it may identify a small subgroup of individuals in whom chronic humoral microvascular injury contributes to allograft dysfunction.

Reappraisal of seventh-day syndrome following living donor liver transplantation

Seventh-day syndrome (7DS) is characterized by sudden failure of a liver graft that had been working normally at about 1 week after transplantation, without an identifiable cause. A nonnegligible percentage of cadaveric liver transplants have shown this type of acute graft failure, whereas 7DS has not been reported after living donor liver transplantation (LDLT). Among 580 adult LDLT recipients in our institution between 1997 and 2003, 3 (0.5%) showed clinical sequences typical of 7DS. All three recipients showed similar but unique clinical sequences, consisting of initial uneventful recovery, dramatic rise of serum liver enzyme levels about 1 week later despite potent antirejection therapy, and subsequent graft loss. Liver biopsy findings were compatible with massive hemorrhagic necrosis. Sustained fever lasting for 2 days preceded deterioration of liver function. All three patients died prior to the opportunity for retransplantation. Our findings suggest that, as in cadaveric donor liver transplantation, 7DS can also occur following LDLT and that a preceding episode of sustained fever may be a prodrome of 7DS although its pathogenesis is yet poorly understood.

Anti-CD95-induced lethality requires radioresistant Fcgamma RII+ cells. A novel mechanism for fulminant hepatic failure

The Jo2 anti-mouse CD95 monoclonal antibody induces lethality in mice characterized by hepatocyte death and liver hemorrhage. Mice bearing a defect in Fas expression or in the Fas-mediated apoptotic pathway are resistant to Jo2. Here we show that FcgammaRII knockout mice or mice with monoclonal antibody-blocked FcgammaRII are also resistant to Jo2. The critical FcgammaRII(+) cells are radioresistant and could not be reconstituted with splenic cells. Death of sinusoidal lining cells and destruction of sinusoids were observed, consistent with the characteristic liver hemorrhage and the selective FcgammaRII expression in sinusoidal lining cells but not hepatocytes. Hemorrhage developed coincident with hepatocyte death and the sharp rise of serum alanine aminotransferase and alanine aminotransferase. Invariably, moribund mice showed severe liver hemorrhage and destruction of sinusoids. The data demonstrate a novel mechanism by which the destruction of liver sinusoids, induced by the Jo2-mediated co-engagement of Fas and FcgammaRII, leads to severe hemorrhage and lethal fulminant hepatitis.

Seventh Day Syndrome--acute hepatocyte apoptosis associated with a unique syndrome of graft loss following liver transplantation

AIM

The aim of this study is to describe a unique 7th day syndrome (7DS), quite different from other causes of post-transplantation allograft dysfunction in a group of orthotopic liver transplant (OLT) patients who needed retransplantation.

METHODS

A retrospective analysis of 594 consecutive OLT over an 8-year period revealed that 10 patients developed allograft dysfunction approximately 7 days following an initially normal graft function.

RESULTS

The features included: (a) severe liver failure; (b) sudden peak of extremely high liver enzymes at approximately day 7; (c) serial liver biopsy findings of central lobular hemorrhage with minimal inflammatory cell infiltrate and (d) an explant with no evidence of vascular thrombosis. The biochemical and morphometric pathological data of these patients were compared with data of patitents who had early acute rejection (AR), hepatic artery thrombosis (HAT), primary nonfunction (PNF), severe sepsis and no dysfunction. Lastly, serial liver core biopsies and explants were tested for evidence of apoptosis, which revealed a significantly higher number of apoptotic hepatocytes in 7DS compared to all control groups.

CONCLUSIONS

Seventh Day Syndrome is a distinct entity associated with early graft dysfunction characterized by a marked apoptosis of hepatocytes. Fas receptor activation or other pathways of program cell death may be implicated in occurrence of 7DS.

"Silent" presentation of veno-occlusive disease after liver transplantation as part of the process of cellular rejection with endothelial predilection

Hemorrhagic centrilobular necrosis and fibrous stenosis of hepatic venules, suggesting veno-occlusive disease (VOD) have rarely been observed after orthotopic liver transplantation (OLT). The aim of this study was to determine the prevalence of this syndrome after OLT in relation to the course with particular reference to acute rejection and to azathioprine administration. VOD was identified in 19 of 1,023 patients transplanted over a 9-year period. VOD occurred at a median of 30 days posttransplantation, without clear cut clinical evidence for hepatic vein outlet obstruction. Seventeen of the 19 patients had an episode of acute rejection before or at the time of VOD. These episodes were compared with that of patients without VOD. In patients with VOD, portal inflammation and endothelialitis were enhanced (P =.014 and P =.048) and endothelialitis was also higher than bile duct damage (P =.03). The incidence of a centrilobular endothelialitis for both groups was not different although an increased trend was observed in the study group (64% vs. 46%; P =.18). The incidence of persistent rejection was similar between both groups (47% vs. 41%). The incidence of chronic rejection was higher in the study group (29% vs. 10%; P =. 04). All patients with VOD received azathioprine as part of immunosuppressive regimen. Despite azathioprine withdrawal, zone 3 changes persisted in 57% of patients. In conclusion, the incidence of VOD was 1.9% after OLT. The association of prominent endothelial involvement and VOD with acute rejection in most cases suggests an immunological phenomenon.

Early graft loss secondary to massive hemorrhagic necrosis following orthotopic liver transplantation. Evidence for cytokine-mediated univisceral Shwartzman reaction

Massive hemorrhagic necrosis (MHN) of the liver following orthotopic liver transplantation (OLT) occurs infrequently during an otherwise uneventful recovery 1 week after OLT. It is characterized by fever and sudden deterioration of allograft function leading to failure in the absence of vascular thrombosis. The etiology is unknown, although it is usually preceded by some degree of allograft rejection. Between 6 and 8 days after OLT, four patients (out of 150) became febrile, hypotensive, and experienced a rapid rise in transaminases within 48 hr. Two patients had evidence of mild rejection; the other two had moderate to severe acute cellular rejection. All patients were ABO identical, crossmatch negative. Bolus steroids were given followed by OKT3 in the two patients with severe rejection. Although sepsis was suspected, antibiotic therapy did not ameliorate the clinical course. Each patient progressed to MHN with severe centrilobular necrosis and variable portal infiltrate. High levels of interferon-gamma and tumor necrosis factor-alpha occurred prior to the rise in transaminases in each MHN patient (155 +/- 39 pg/ml and 414 +/- 201 pg/ml, respectively) compared with levels in OLT patients with severe rejection (14 +/- 4 pg/ml and 26 +/- 5 pg/ml, respectively, P < 0.05). These data support the concept of a cytokine-mediated inflammatory response leading to a univisceral Shwartzman reaction in the transplanted liver. Early recognition of this syndrome and retransplantation are critical for survival.

Expression of complement-regulatory proteins in normal and UW-preserved human liver

BACKGROUND/AIMS

Somatic cells are protected against complement-mediated injury by specialized membrane proteins, known as complement-regulatory proteins (CRP). The knowledge of the pattern of CRP expression in the liver is important to evaluate the role of complement-mediated injury in graft rejection.

METHODS

We determined the distribution of four main CRP: membrane cofactor protein (MCP), decay accelerating factor (DAF), protectin, and complement receptor 1 (CR1) in 30 histologically normal livers, 13 samples from University of Wisconsin cold-storage solution (UW)-preserved tissue and 17 postoperative biopsies of UW-preserved allografts.

RESULTS

In normal liver, hepatocytes expressed only MCP. Bile duct cells were reactive for MCP and protectin. Sinusoidal endothelial cells expressed MCP and protectin but displayed no or faint expression of DAF. Endothelial cells of portal vessels and centrilobular veins expressed high levels of DAF, MCP, and protectin. No expression of CR1 was observed. No change in CRP expression was usually detected after UW preservation, except for protectin, induced on hepatocytes in 9 samples of UW-preserved liver tissue and in 9 allografts.

CONCLUSIONS

Hepatocytes and sinusoidal endothelial cells, which have a defective expression of CRP, might be at risk for complement-mediated injury. However, this risk is not aggravated after UW preservation.

Angiographically determined arteriopathy in liver graft dysfunction and survival

We evaluated the contribution of flush and selective hepatic angiography in defining the extent and pattern of major vessel and microvascular arterial lesions and their significance in graft survival. The 50 consecutive patients investigated comprised three clinical groups: Group A (n = 18) were patients with severe graft dysfunction within the first seven days post-transplantation. In this group six of 18 angiograms demonstrated intrahepatic attenuation of the arterial tree suggestive of acute cellular rejection and four of these grafts were lost, compared to a 78% graft survival in the non-arteriopathic group. Group B (n = 16) comprised patients with clinically suspected hepatic arterial thrombosis or stenosis, these diagnoses were confirmed in all patients compared to only 10 positive findings with doppler ultrasonography. Graft survival was only 10% in those patients with artery thrombosis as compared to 100% in those with arterial anastomotic stenoses. Group C patients (n = 16) had histologically confirmed chronic allograft rejection and in ten of them (65%) evidence of arteriopathy was demonstrated despite histological evidence of arteriopathy being present in only 19% of patients. All patients in this group with arteriopathic changes lost their grafts with the exception of one successfully treated with FK506. In two other patients reversibility of chronic rejection was observed, neither of whom had evidence of an arteriopathy.

Toga virus-like particles in acute liver failure attributed to sporadic non-A, non-B hepatitis and recurrence after liver transplantation

Toga virus-like particles (typically 60-70 nm: enveloped with small surface spikes) were detected in the native hepatectomy specimens in 7 of 18 patients grafted for acute liver failure attributed to sporadic non-A, non-B hepatitis and in 2 patients grafted for fulminant hepatitis attributed to anti-epileptic drug hepatotoxicity. These particles were not detected in the hepatectomies from 12 other patients grafted for other causes of acute liver failure, 12 for various chronic liver diseases, and 2 histologically normal livers. Acute hepatic failure, characterized histologically by severe haemorrhagic necrosis, developed 7 days after grafting in 5 patients, all in the non-A, non-B group with toga virus-like particles in native liver. Similar virus-like particles were detected in all grafts and were in greater abundance than in the native livers. The agent may be novel because pre- and post-grafting sera were negative for antibodies against representative panels of arboviruses and in first and second generation antibody tests for hepatitis C virus.

Liver transplantation

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Immunological aspects of clinical liver transplantation

With the improved survival achieved in the 1980s it has become apparent that graft rejection is a major problem following liver transplantation [1]. Hyperacute rejection is uncommon, although syndromes of fulminant graft failure due to immunological mechanisms have been described. Acute cellular rejection occurs in approximately 70% of patients and usually responds to high-dose steroids. Between 10 and 15% develop chronic rejection, characterised by a progressive destruction of intrahepatic bile ducts which is irreversible [2]. The principal targets of both acute and chronic liver allograft rejection are intrahepatic bile ducts and endothelium [2]. The increased ability of these cell types to express MHC antigens and adhesion molecules may be responsible for their involvement [2, 3] and may be enhanced by the release of proinflammatory cytokines associated with viral infection, particularly CMV [3]. Although the importance of HLA matching remains unknown patients transplanted with ABO incompatible livers have a higher incidence of graft rejection [4]. Lymphocytes probably instigate rejection but liver damage may result from the recruitment of several effector mechanisms involving the activation of neutrophils, macrophages and B cells as well as cytotoxic T cells [5]. Clinical studies are required to determine the optimum immunosuppressive management of liver transplants and in particular to assess the role of new immunosuppressive agents such as monoclonal antibodies and FK506.

Changes in the expression of major histocompatibility complex class II antigens in liver allograft rejection

The expression of major histocompatibility complex (MHC) class II antigens was studied in human liver grafts by immunohistochemical staining with monoclonal antibodies to HLA-DR, HLA-DP, and HLA-DQ antigens. Staining was carried out on frozen sections from 13 normal livers, used as controls, and 85 post-transplant specimens in six histological categories: acute rejection (n = 25); chronic rejection (n = 21); massive haemorrhagic necrosis (n = 2); resolving acute rejection (n = 10); non-rejection complications--pure cholestasis, ischaemia, biliary obstruction (n = 23); and stable graft function greater than 1 year post-transplantation (n = 4). Staining was graded semi-quantitatively on a scale of 0-3+ in bile ducts, hepatocytes, and vascular endothelium. Expression of class II antigens was increased in bile ducts, hepatocytes, and vascular endothelium in all of the post-transplant groups compared with controls. The degree of expression of HLA-DR and HLA-DP in bile ducts and vascular endothelium was significantly greater in cases of rejection than in the non-rejection groups. These observations suggest that increased class II antigen expression may be important in the pathogenesis of immune-mediated bile duct and endothelial damage in liver allografts. Immunohistochemical staining for class II antigens in post-transplant biopsies may also be useful as an adjunct to conventional histological diagnosis.

Portal lymphadenopathy associated with lipofuscin in chronic cholestatic liver disease

To determine whether portal lymphadenopathy in primary biliary cirrhosis is caused by deposition of lipofuscin pigment in sinus histiocytes and to compare primary biliary cirrhosis with other liver diseases a retrospective study on a consecutive series of 169 livers obtained at transplantation was carried out. There were grouped into eight diagnostic categories: primary biliary cirrhosis (n = 51), primary sclerosing cholangitis (n = 10), extrahepatic biliary atresia (n = 6), chronic rejection (n = 9), cirrhosis (other causes) (n = 38), primary liver neoplasia (n = 21), acute liver disease (n = 20), and retransplantation (other) (n = 14). Lymph nodes were present in 66 specimens. Fifty of these contained granules of lipofuscin pigment. The highest incidence of lymph node enlargement and the largest amounts of pigment were present in cases of primary biliary cirrhosis. A similar pattern of lymph node enlargement was also commonly observed in other chronic cholestatic conditions (primary sclerosing cholangitis, biliary atresia, chronic rejection). Much less pigment was seen in nodes draining livers with non-cholestatic cirrhosis or primary tumours. Nodes were not found in acute liver disease. It is concluded that portal lymphadenopathy associated with lipofuscin is a common finding in various chronic cholestatic liver diseases. The pathogenesis of this lesion is uncertain. Most cases are asymptomatic with enlarged nodes which may be detected only at laperotomy or necropsy and may be wrongly attributed to neoplastic disease. Diagnostically, the finding of large amounts of lipofuscin in enlarged portal lymph nodes is a good indicator of underlying chronic cholestatic liver disease.