Lack of association between cytomegalovirus infection, HLA matching and the vanishing bile duct syndrome after liver transplantation

Revaluation of vanishing bile duct syndrome

Vanishing bile duct syndrome (VBDS) can result from multiple etiologies, including congenital and genetic diseases, ischemic causes, neoplastic disorders, infections, immune disorders, drugs, idiopathic adulthood ductopenia (IAD) and so on. Recently, lymphoma, HIV/AIDS and drugs were identified to be major etiologies in the reported cases, some of which presented complex clinical course and were contributed by more than one etiological factor. Hepatic biopsy must be done for the diagnosis of VBDS and immunohistochemical staining for cytokeratin 7 (CK7) and CK19 has contributed to the establishment of diagnosis of VBDS. VBDS can be usually treated with symptomatic and supportive therapy, etiological therapy, liver transplantation, ursodeoxycholic acid and immunosuppressive agents. Glucocorticoids can be tried to switch to mycophemolate mofeil or tacrolimus when their effects are poor or side effects are severe. Severe cases ought to receive multimodality therapy besides plasmapheresis.

Role of Polymerase Chain Reaction in the Diagnosis of Cytomegalovirus Infection in Liver Transplant Patients

Eighty-eight formalin-fixed, paraffin-embedded needle biopsies from 58 liver trans plant recipients were analyzed for the presence of cytomegalovirus (CMV) by light microscopy and the polymerase chain reaction (PCR). Twenty-seven biopsies were positive for CMV by both light microscopy and PCR, 41 were negative by both methods, 17 were positive by PCR only, and 3 were positive by light microscopy only. In the absence of cytomegalic cells, immunohistochemical staining was unable to detect CMV that could have been identified by PCR. Serum total bilirubin was higher in patients whose biopsies contained PCR (but not histologic) evidence of CMV infection. No evidence of association of the presence of CMV was found by either PCR or light microscopy with serum levels of aminotransferase or alkaline phosphatase, nor with histologic evidence of rejection or hepatitis. PCR was negative for CMV in 22 liver biopsies from immunocompetent individuals without evidence of hepatic dysfunction. Although PCR can detect the presence of CMV in the absence of cytomegalic cells, the clinical significance of PCR-proven, histologically undetectable CMV in the liver is undetermined. Int J Surg Pathol 2(3):221-226, 1995

Diagnosis and management of allograft failure

The article focuses on diagnosis and management of allograft failure in four main categories: (1) ischemic-reperfusion injury (primary nonfunction), (2) technical complications (hepatic artery and portal vein thrombosis), (3) chronic rejection, and (4) recurrent disease. It also discusses the complex problems involved in retransplantation for allograft failure.

Cytomegalovirus and chronic allograft rejection in liver transplantation

Cytomegalovirus (CMV) remains one of the most frequent viral infections and the most common cause of death after liver transplantation (LT). Chronic allograft liver rejection remains the major obstacle to long-term allograft survival and CMV infection is one of the suggested risk factors for chronic allograft rejection. The precise relationship between cytomegalovirus and chronic rejection remains uncertain. This review addresses the morbidity of cytomegalovirus infection and the risk factors associated with it, the relationship between cytomegalovirus and chronic allograft liver rejection and the potential mechanisms of it.

Chronic rejection of small bowel grafts: pediatric and adult study of risk factors and morphologic progression

One hundred and seventy-two patients underwent small bowel transplantation at Children's Hospital of Pittsburgh and University of Pittsburgh Medical Center between May 1990 and August 2001. Thirty-four patients had complete or partial resection of their primary graft and in 15, histologic features of chronic rejection were present in the resected small bowel. This is a descriptive and correlative study of the demographic, perioperative, and histologic features associated with progression to intestinal graft failure. Variable features associated with an increased risk of chronic rejection included acute rejection within the 1st month, increased number and higher grade of acute rejection episodes, isolated small bowel grafts rather than small bowel-liver grafts, older recipient age, non-Caucasian race, and Caucasian to non-Caucasian transplant. The mucosal biopsies showed predictive changes many months before the grafts were excised. The mucosal biopsy diagnosis of chronic vascular rejection can be difficult because the affected vessels, the distal branches of the mesenteric arteries, and the larger arteries of the subserosa and submucosa are not routinely sampled. The possibility of underlying arteriopathy, however, can be inferred in some instances from the presence of secondary mucosal changes in the small bowel biopsies though the "early" changes lack specificity. It is the progression of biopsy findings over time that is predictive of outcome. It is important to recognize the persistence of "late" mucosal changes of chronic rejection so that patients are not subjected to increased immune suppression when it is unlikely to be of significant benefit.

Impact of human leukocyte antigen matching in liver transplantation

BACKGROUND

Human leukocyte antigen (HLA) compatibilities are beneficial in the setting of kidney transplantation but have demonstrated inconclusive results after liver transplantation. On the basis of recent controversial reports, the authors analyzed the impact of HLA matching in their patients after liver transplantation under modern immunosuppressive drug regimens and new HLA typing techniques with respect to outcome and adverse immunologic events.

METHODS

Data from 924 transplants with complete donor-recipient HLA typing were retrospectively analyzed. Immunosuppression was commenced as either cyclosporine A- or tacrolimus-based therapy in different protocols. The follow-up period ranged from 1 to 144.8 months (median, 66 months).

RESULTS

The actuarial graft survival was 88% after 1 year and 78.7% after 5 years and was similar in tacrolimus- and cyclosporine A-treated patients. However, cyclosporine A-treated patients underwent significantly more rejection episodes. The number of HLA compatibilities had no influence on graft survival, whereas the number of acute rejections was significantly less in transplants with more HLA compatibilities (P<0.05). Graft survival tended to be improved in patients with chronic hepatitis B and more HLA compatibilities (P=0.05). In contrast, graft survival in transplants for primary sclerosing cholangitis was significantly impaired in the presence of one or two HLA-DR compatibilities (P<0.05). In addition, in autoimmune hepatitis, survival tended to be lower in the presence of more HLA compatibilities (P=0.1). Overall graft survival or frequency of adverse immunologic events was not influenced by any specific donor-recipient HLA allele.

CONCLUSION

This study demonstrated fewer acute rejections in transplants with more HLA compatibilities. However, in liver transplantation, a more specific investigation of HLA typing may be necessary, because in some indications HLA antigens play a role in the nature of the disease. Therefore, recurrence of autoimmune disease may be more severe in patients sharing HLA antigens.

CMV hepatitis after liver transplantation: incidence, clinical course, and long-term follow-up

Cytomegalovirus (CMV) hepatitis is described as the most frequent manifestation of CMV tissue invasive disease after liver transplantation. Its correlation with HLA-matching, hepatic artery thrombosis, and chronic rejection is still controversial. Risk factors, incidence, clinical course, and complications of CMV hepatitis were retrospectively analyzed in a 12-year series of 1,146 consecutive liver transplantations in 1,054 patients. All patients received only low-dose acyclovir but no gancyclovir prophylaxis. CMV infection was diagnosed by viral culture, pp65 antigenemia, or by polymerase chain reaction (PCR). CMV hepatitis was proven by liver biopsy. Treatment of CMV disease consisted of intravenous ganciclovir for a minimum of 14 days. Long-term follow-up of patients included monthly routine laboratory values and routine liver biopsies 1, 3 and 5 years after transplantation. CMV hepatitis was a rare event after liver transplantation, with a total incidence of 2.1% (24 cases). It was significantly more frequent in CMV seronegative (5.2%) than in seropositive recipients (0.7%). The leading indication in patients with CMV hepatitis was HCV cirrhosis (n = 8). The maximum number of pp65 positive white blood cells was 82 +/- 23 per 10,000 cells. Most courses manifested as isolated hepatitis; only 2 patients had disseminated disease. Nine of 24 patients had received OKT3 monoclonal antibodies because of steroid-resistant rejection before CMV hepatitis. In seronegative patients with CMV hepatitis, 71% revealed 1 or 2 HLA DR matches, in contrast to 32% in patients without CMV hepatitis. One-, 3-, and 5-year graft survival was 78%, 65%, and 59% in patients with CMV hepatitis compared with 88%, 81%, and 79% in patients without. Chronic rejection was observed in one patient, but already before onset of CMV hepatitis. Beneath D+R-constellation and OKT3 treatment as risk factors, HLA DR-matched grafts and HCV seem to favor manifestation of CMV hepatitis after liver transplantation. Long-term complications of CMV hepatitis were not observed, and especially no correlation with chronic rejection was found.

Infections and solid organ transplant rejection: a cause-and-effect relationship?

Although evidence is far from being conclusive, several studies have suggested that infections could trigger rejection in different transplant settings. In this review we examine the evidence linking cytomegalovirus (CMV), adenovirus, enterovirus, parvovirus, and herpes simplex virus infections to the vasculopathy leading to cardiac allograft rejection, the association between CMV and chronic kidney, lung, and liver graft rejection, and the association of human herpesvirus 6 reactivation with CMV-related disease in kidney and liver transplant recipients. We also review the numerous antiviral prophylactic or pre-emptive treatments in use to control CMV infection, and suggest that they do not limit immune reactions leading to graft rejection or lower the risk of developing post-transplantation atherosclerosis in allograft recipients. Finally, we emphasise the need for prospective, international studies to clarify the role of infections in transplant rejection, to look at virus-to-virus interactions, and to establish specific therapeutic strategies. Such strategies must not rely exclusively on expensive antiviral agents but also on vaccination or other, innovative approaches, such as the use of agents able to inhibit the activity of natural killer cells, which might have an important role in acute allograft rejection.

Acute cellular rejection in liver transplant recipients under cyclosporine immunosuppression: predictive factors of response to antirejection therapy

BACKGROUND

Predictive factors of response to antirejection therapy in acute cellular rejection (ACR) in liver transplantation are not well established.

METHODS

To investigate the possible existence of these factors, we reviewed 111 consecutive episodes of ACR fulfilling the following criteria: histologically confirmed ACR; cyclosporine-based immunosuppression; initial antirejection treatment with high-dose steroid boluses; minimum follow-up of 2 weeks after treatment; and no other graft complication interfering with evaluation of therapeutic response. ACR episodes not responding to initial steroid therapy were given additional treatment (OKT3 and/or repeated steroid boluses). We analyzed the association of the response to the antirejection treatment with different clinical, laboratory, histological, and donor-recipient compatibility variables at two times: after the initial antirejection therapy, and after all the antirejection therapy administered.

RESULTS

Eighty episodes of ACR (72%) resolved after the initial therapy with high-dose steroid boluses, and another 18 (16%), initially steroid-resistant, resolved with additional antirejection treatment. Thirteen episodes (12%) were refractory to all antirejection treatment administered. Variables with independent predictive value of nonresponse to initial therapy with steroid boluses were late-onset ACR (>2 months after transplantation), high serum bilirubin and alanine aminotransferase, low blood cyclosporine concentration in the week before antirejection treatment, and severe histological endothelialitis. Late-onset ACR and high serum bilirubin were also independent predictors of refractoriness to all the treatment administered.

CONCLUSIONS

Response to antirejection treatment in ACR in liver transplantation can be predicted by several clinical and laboratory data. ACR episodes with factors predictive of therapeutic unresponsiveness could benefit from more aggressive antirejection treatment.

Risk factors for chronic rejection after pediatric liver transplantation

BACKGROUND

Chronic rejection is a major cause of graft failure and a frequent reason for retransplantation after pediatric liver transplantation. Identification of risk factors for chronic rejection in pediatric transplant recipients is vital to understanding the pathogenesis of chronic rejection and may help prevent further graft loss.

METHODS

The study population consisted of 285 children with 385 liver transplants performed at University of Chicago between 1991 and 1999. Logistic regression analysis was used to evaluate risk factors for chronic rejection, including age, sex, race, type of graft (living related vs. cadaveric), native liver disease, acute rejection episodes, cytomegalovirus (CMV) infection, and posttransplant lymphoproliferative disease (PTLD).

RESULTS

The chronic rejection rate was significantly lower in recipients of living-related grafts than in recipients of cadaveric grafts (4% vs. 16%, P=0.001). African-American recipients had a significantly higher rate of chronic rejection than did Caucasian recipients (26% vs. 8%, P<0.001). Numbers of acute rejection episodes, transplantation for autoimmune disease, occurrence of PTLD, and CMV infection were also significant risk factors for chronic rejection. However, recipient age, gender, donor-recipient gender mismatch, and donor-recipient ethnicity mismatch were not associated with higher incidence of chronic rejection

CONCLUSION

We have identified a number of risk factors for chronic rejection in a large group of pediatric liver allograft recipients. We believe that donor-recipient matching for gender or race is not likely to reduce the incidence of chronic rejection. The elucidation of the mechanisms by which living-related liver transplantation affords protection against chronic rejection may provide insight into the immunogenetics of chronic rejection and help prevent further graft loss.

Prospective randomized trial to assess the value of preemptive oral therapy for CMV infection following liver transplantation

BACKGROUND

With the development of sensitive tests to detect cytomegalovirus (CMV) viremia, preemptive approaches become a reasonable alternative to general CMV prophylaxis. We performed a randomized trial comparing pp65-antigenemia guided preemptive therapy using oral ganciclovir with symptom-triggered intravenous ganciclovir treatment.

METHODS

Eighty-eight of 372 liver transplant recipients developed antigenemia early after orthotopic liver transplantation. Twenty-eight symptomatic patients with antigenemia were excluded from randomization and treated with intravenous ganciclovir. Sixty pp65-antigen-positive asymptomatic patients were randomized to receive either oral ganciclovir 3x1 g/day for 14 days (group 1) or no preemptive treatment (group 2). Patients that developed CMV disease were treated with intravenous ganciclovir 2x5 mg/kg body weight for 14 days. The high-risk (Donor+/Recipient-) patients were equally distributed in the two study groups.

RESULTS

Three of 30 (10%) patients on oral ganciclovir developed mild to moderate CMV disease compared with 6/30 (20%) patients in the control group. In the Donor+/Recipient- patients, the incidence of CMV disease was 1/6 and 3/7. All disease episodes resolved after intravenous treatment. The 1- and 3-year patient and organ survival was the same in the study groups and in the patients with or without CMV infection. No deaths related to CMV occurred.

CONCLUSIONS

The positive predictive value of pp65-antigenemia for the development of CMV disease was very low, and, in 28/88 patients (32%), antigenemia did not precede symptoms. Therefore, pp65-antigenemia is of limited value in deciding on the timing and need for ganciclovir therapy after liver transplantation.

An association between cytomegalovirus infection and chronic rejection after liver transplantation

BACKGROUND

Previous studies suggest a link between cytomegalovirus (CMV) infection and chronic rejection. Since these studies, more sophisticated diagnostic methods with high sensitivity and specificity for CMV have been developed and effective therapy/prophylaxis for CMV is now available. We sought CMV prospectively by polymerase chain reaction of serum and urine and by conventional methods in a group of 33 patients undergoing 57 transplants during 1993 or 1994, selected from a larger series. There were 13 grafts lost to chronic rejection. The remaining 44 grafts that did not develop chronic rejection served as controls and comprised 15 successful primary grafts, 15 second transplants, 8 third transplants, and 6 primary grafts that were lost for reasons other than chronic rejection.

RESULTS

The combination donor CMV antibody negative with recipient antibody positive and the duration of CMV infection >30 days were associated with an increased relative risk of chronic rejection. In contrast, the presence of CMV infection alone, symptomatic CMV infection, the detection of CMV by PCR of serum or urine, and the peak/cumulative viral load were not predictive. CMV infection occurred earlier in those undergoing a second transplant for chronic rejection than for those undergoing a second transplant for other reasons. In addition, a human leukocyte antigen B mismatch was associated with prolonged CMV infection.

CONCLUSION

These data are consistent with the hypothesis that prolonged subclinical cytomegalovirus infection is associated with an increased risk of chronic rejection.

Association between cytomegalovirus disease and chronic rejection in kidney transplant recipients

BACKGROUND

It has long been suggested that cytomegalovirus (CMV) disease plays a role in the pathogenesis of chronic rejection (CR). However, its role has been difficult to prove, given the strong association between acute rejection and CMV, and the even stronger association between acute rejection and CR. To try to isolate the relative contribution of CMV infection in the pathogenesis of CR, we used multivariate techniques to examine risk factors for CR, including CMV disease.

METHODS

Our study population consisted of adult recipients of a first kidney graft who underwent transplantation at a single center between 1/1/85 and 6/30/97 (n = 1339).

RESULTS

Multivariate analysis using time to CR as the dependent variable demonstrated acute rejection to be the strongest risk factor (relative risk [RR] = 17.8, P = 0.0001), followed by older donor age (RR = 1.46, P = 0.01). The presence of CMV disease showed a trend toward increased risk for CR (RR = 1.30, P = 0.10), although the association was not as strong as with the other two variables. Comparing only those recipients with acute rejection and CMV disease versus those with acute rejection but no CMV disease, the relative risk of developing CR was 1.37 times higher in the former group. Recipients with acute rejection and CMV developed CR sooner and with a higher incidence versus those with acute rejection but no CMV (P = 0.002). It is interesting, however, that CMV disease was only a risk factor for CR in the presence of acute rejection. Recipients with no acute rejection and CMV disease did not have a higher incidence of CR versus those with no acute rejection and no CMV (P = NS).

CONCLUSION

CMV disease seems to play some role in the pathogenesis of CR but only in the presence of acute rejection. Reasons may include (i) the inability to adequately treat acute rejection due to the presence of CMV disease or (ii) the increased virulence of latent CMV virus in recipients being treated for acute rejection. Our data may suggest a role for more aggressive prophylaxis against CMV disease, especially at the time of treatment for acute rejection.

Cytomegalovirus infection of bile duct epithelial cells, hepatic artery and portal venous endothelium in relation to chronic rejection of liver grafts

BACKGROUND/AIM

Chronic rejection is an important cause of graft loss following liver transplantation. A number of risk factors for chronic rejection have been identified previously, albeit inconsistently. These include cytomegalovirus infection detected by a number of different techniques, including immunohistochemical staining and in situ hybridisation of liver grafts. However, tissue-based techniques for the detection of CMV have not been applied to grafts lost to conditions other than chronic rejection. The purpose of this study was to investigate the relationship between the presence of cytomegalovirus infection detected by in situ hybridisation and immunohistochemistry with respect to graft outcome, the presence of cytomegalovirus infection detected by other techniques and in addition, the type of infected cell.

METHODS

The 29 patients studied included 15 patients who lost their primary liver graft to chronic rejection in 8 cases, to hepatic artery thrombosis in 4 cases and to causes other than chronic rejection or hepatic artery thrombosis in 3 further cases. In each case, sections containing septal or large ducts and vessels were selected (usually blocks) since these may be more representative. Needle biopsies from 14 further patients who ultimately achieved satisfactory graft function served as control tissue. Of these, ten had evidence of cytomegalovirus infection at the time of study by serum/urine PCR, DEAFF testing or seroconversion, while 4 patients had no evidence of cytomegalovirus infection according to these techniques.

RESULTS

Cytomegalovirus infection was detected in the liver of 12 of the 29 patients. These included 8/15 grafts lost, which comprised 3/8 with chronic rejection, 2/3 with hepatic artery thrombosis and 3/4 with grafts lost to other causes, as well as 4/14 who retained grafts. CMV was detected most commonly in association with symptomatic infection and notably was detected only by in situ hybridisation in two cases. Predominant cell types that contained cytomegalovirus were hepatocytes and mononuclear cells. However, bile duct epithelial cells, hepatic artery endothelial cells and portal venous endothelial cells also contained cytomegalovirus in some cases.

CONCLUSIONS

These data support previous studies that cytomegalovirus infection is detectable in patients with chronic rejection and are consistent with the theory that CMV is involved in chronic rejection. However, cytomegalovirus infection was detected in explanted grafts lost to conditions other than chronic rejection, and the association may not be causal but a consequence of graft injury.

Analysis of the reversibility of chronic liver allograft rejection implications for a staging schema

In contrast to all other vascularized organ allografts, chronic rejection (CR) of the liver is potentially reversible. We therefore studied demographic, perioperative, biochemical, and histologic features associated with reversibility or progression to graft failure. Using very stringent clinical and histological criteria, we identified a subgroup of 23 of 916 patients receiving primary liver allografts with CR from the Liver Transplantation Database. Of these, 13 experienced graft failure as a result of CR, and 10 patients recovered to normal histology or liver injury test results. Male-to-female sex mismatch (p = 0.07), younger recipient age (p = 0.09), younger donor age (p = 0.06), white-to-white race match (p = 0.09), primary diagnosis of biliary atresia (p = 0.02), and cold ischemia time of more than 12 hours (p = 0.02) were associated with graft failure. Patients who eventually recovered from CR were more likely to have acute rejection within the first 2 weeks (70% vs 23%; p = 0.04), had a higher number of acute rejection episodes (p = 0.08), and were more likely to have been treated with OKT3 (90% vs 46%, p = 0.07). Although overlap existed in the histopathologic findings between the patients whose grafts failed and those who recovered, those patients who developed bile duct loss in more than 50% of the portal tracts (p < 0.01), severe (bridging) perivenular fibrosis (p = 0.05), and the presence of foam cell clusters (p = 0.06) were more likely to require retransplantation. In contrast to other solid organ allografts, CR of the liver is not an irreversible process. These findings can be used to understand the evolution of CR and to design a biologically correct and clinically relevant staging system.

Evolving concepts in the diagnosis, pathogenesis, and treatment of chronic hepatic allograft rejection

Chronic hepatic allograft rejection is characterized by the histological findings of ductopenia and a decreased number of hepatic arteries in portal tracts in the presence of foam cell (obliterative) arteriopathy. Recent studies have extended the histological spectrum of chronic rejection to include the presence of biliary epithelial atrophy or pyknosis involving the majority of small ducts present in the liver biopsy specimen. Overall, the incidence of chronic rejection in adults appears to be decreasing and is currently approximately 4%. However, the incidence of chronic rejection in pediatric liver transplant recipients has been more stable and ranges from 8% to 12% in most studies. Clinical risk factors associated with chronic rejection include: underlying liver disease, HLA donor-recipient matching, positive lymphocytotoxic cross-match, cytomegalovirus infection, recipient age, donor-recipient ethnic origin, male donor into female recipient, number of acute rejection episodes, histological severity of acute rejection episodes, low cyclosporine trough levels, and retransplantation for chronic rejection. Chronic rejection, once diagnosed, frequently leads to graft failure; however, a number of reports indicated 20% to 30% of the patients with this diagnosis may respond to additional immunosuppressive therapy or even resolve spontaneously receiving baseline immunosuppression. Newer immunosuppressive agents, such as tacrolimus and mycophenolate, may successfully reverse chronic rejection, particularly when it is diagnosed in its early histological stages.

Cholangitis in viral disease

This review of biliary manifestations of viral diseases includes aspects of morphologic diagnosis, therapeutic implications, prognostic effect, and natural history. The viral causes of cholangitis are reviewed, with subclassification on the basis of primary hepatic versus systemic infections and immune competence of the host. Special attention is given to the histopathologic and clinical features of viruses affecting the biliary tree. Among hepatotropic viruses, hepatitis C more frequently is associated with cholangitis than is hepatitis B. In both hepatitis B and hepatitis C, the lymphocytic cholangitis duct damage is reversible and does not adversely influence the course of disease or response to therapy. Hepatitis A and hepatitis E, despite causing clinical cholestasis, do not result in severe cholangitis. The effect of systemic viruses on the biliary tree is primarily dependent on the status of the host immune system. Infants and severely immunosuppressed patients (such as those who have undergone liver transplantation) are at risk for cytomegalovirus cholangitis, whereas patients with late-stage acquired immunodeficiency syndrome (AIDS) are at risk for cholangitis due to numerous organisms. Overall, cholangitis attributable to viral disease encompasses a wide spectrum of clinicopathologic scenarios, depending on the etiologic virus and the immune competence of the host.

Prophylaxis of cytomegalovirus infection in liver transplantation: a randomized trial comparing a combination of ganciclovir and acyclovir to acyclovir. NIDDK Liver Transplantation Database

BACKGROUND

The optimal prophylactic regimen to prevent cytomegalovirus (CMV) infection and disease in orthotopic liver-transplant patients remains to be established. We tested whether a combination of intravenous ganciclovir (GCV) followed by high dosages of oral acyclovir (ACV) for 4 months provided a higher degree of protection from CMV than oral ACV alone.

METHODS

One hundred sixty-seven liver-transplant recipients were randomized to receive 120 days of antiviral treatment starting at the time of transplantation consisting of either ACV 800 mg orally four times daily (n=84) or 14 days of GCV 5 mg/kg intravenously every 12 hr followed by oral ACV 800 mg four times daily (n=83). Prospective laboratory and clinical surveillance was performed to determine primary endpoints (onset of CMV infection and CMV disease) and secondary endpoints (rates of fungal and bacterial infection, allograft rejection, and survival after transplantation). One-year event rates are presented as cumulative percentages.

RESULTS

During the first year after transplantation, CMV infection developed in 57% of patients treated with ACV and in 37% of patients treated with GCV + ACV (P=0.001). CMV disease developed in 23% of patients treated with ACV and in 11% of patients treated with GCV + ACV (P=0.03). In seronegative recipients of allografts from CMV-seropositive donors (D+/R-), CMV disease developed in 58% of patients treated with ACV and in 25% of patients treated with GCV + ACV (P=0.04). In the D+/R- group, 54% of patients treated with ACV and 17% of patients treated with GCV + ACV developed infection with Candida albicans (P=0.05).

CONCLUSIONS

Prophylaxis of CMV infection in liver-transplant patients with 14 days of intravenous GCV followed by high-dosage oral ACV is more effective than high-dosage oral ACV alone at reducing CMV infection and disease, even for patients in the D+/R- CMV serological group.

Long-term prognosis of renal transplantation after preemptive treatment of cytomegalovirus infection

A role for cytomegalovirus (CMV) infection in the etiologies of acute and chronic rejection in renal allograft recipients has been suggested. We previously reported that preemptive treatment of CMV infection with ganciclovir in kidney transplant patients was safe and effective. We now present a retrospective analysis of 169 consecutive renal transplant patients, of whom 87 (51.5%) received preemptive treatment with ganciclovir (CMV(+) group). No patient died of CMV infection. Actuarial graft and patient survival rates were not different between the CMV(+) and the CMV(-) groups (graft survival: 68% and 69%; patient survival: 89% and 88%, respectively). At the end of the study, the mean plasma creatinine levels were not statistically different between the two groups (185+/-13 and 166+/-12 micromol/L for the CMV(+) group and the CMV(-) group, respectively). These results suggest that preemptive treatment of CMV infection with ganciclovir may prevent the CMV-induced renal injury and graft loss.

Cytomegalovirus infection does not increase the risk of vanishing bile duct syndrome after liver transplantation

Cytomegalovirus (CMV) infection and HLA-DR sharing have been reported to be associated with the development of vanishing bile duct syndrome (VBDS) after liver transplantation. We retrospectively analyzed the importance of these risk factors for VBDS in 126 consecutive recipients of a first transplant. In contrast to previous studies, CMV was monitored strictly using the antigenemia assay, a quantitative marker of the viral load. Patient and graft survival were comparable in patients with and without CMV infection. The incidence of VBDS was low, regardless of the CMV infection status or degree of HLA-DR sharing. Improvements in the early diagnosis and treatment of CMV infection may have eliminated its negative influence on graft survival.

Persistent cytomegalovirus in liver allografts with chronic rejection

Cytomegalovirus (CMV) infection is one of the suggested risk factors for chronic allograft rejection. Clinical and experimental studies have shown that CMV is somehow implicated in rejection mechanisms and in the generation of graft arteriosclerosis, characteristic of chronic rejection. In liver transplantation, there is also evidence of an association between CMV and vanishing bile duct-syndrome (VBDS), which is characteristic of chronic liver allograft rejection. In this study, the role of posttransplant CMV infection and of acute rejection in the patients with irreversible, histologically confirmed chronic liver rejection with VBDS and vasculopathy was analyzed. Ten of 200 (5%) consecutive liver transplants were lost due to chronic rejection, from between 5 and 28 months from transplantation. In these 10 patients, acute rejections were frequent, and nine of ten patients had at least one episode of rejection early after transplantation. All patients (10 of 10) had a history of CMV infection usually following acute rejection. To investigate the role of CMV in chronic rejection, nine available removed grafts were examined for the presence of the CMV genome by DNA-hybridization in situ using a biotinylated CMV-DNA probe. Persistent CMV-DNA was found in all of those available grafts with chronic rejection. CMV-DNA was strongly expressed in the remaining bile ducts and moderately expressed in the endothelial cells of the vascular structures, the CMV positivity of hepatocytes varied from graft to graft. Thus, persistent CMV genome was found in those structures that are the major targets of the chronic rejection process in the liver. These findings support the previous suggestion of an association between CMV and chronic allograft rejection.

Infections in solid-organ transplant recipients

Solid-organ transplantation is a therapeutic option for many human diseases. Infections are a major complication of solid-organ transplantation. All candidates should undergo a thorough infectious-disease screening prior to transplantation. There are three time frames, influenced by surgical factors, the level of immunosuppression, and environmental exposures, during which infections of specific types most frequently occur posttransplantation. Most infections during the first month are related to surgical complications. Opportunistic infections typically occur from the second to the sixth month. During the late posttransplant period (beyond 6 months), transplantation recipients suffer from the same infections seen in the general community. Opportunistic bacterial infections seen in transplant recipients include those caused by Legionella spp., Nocardia spp., Salmonella spp., and Listeria monocytogenes. Cytomegalovirus is the most common cause of viral infections. Herpes simplex virus, varicella-zoster virus, Epstein-Barr virus and others are also significant pathogens. Fungal infections, caused by both yeasts and mycelial fungi, are associated with the highest mortality rates. Mycobacterial, pneumocystis, and parasitic diseases may also occur.

Failed allografts and causes of death after orthotopic liver transplantation from 1985 to 1995: decreasing prevalence of irreversible hepatic allograft rejection

Mayo Clinic pathology files from March 1985 to March 1995 contained records of 584 orthotopic liver transplantations in 515 patients. The most common indication for liver transplantation was primary sclerosing cholangitis (PSC), followed by primary biliary cirrhosis (PBC), and cryptogenic cirrhosis. In 59 patients, a total of 69 single or repeated retransplantations became necessary. Vascular complications necessitated retransplantation in 35 cases, followed by irreversible rejection in 16 cases, and primary graft failure in 8 cases. Ninety-nine patients died, 25 of them after one or more retransplantations. Infectious complications caused death in 38 cases, followed by graft-related complications (excluding rejection) in 22 cases, noninfectious systemic diseases such as intracerebral hemorrhage (21 cases), malignancies in 13 cases, and irreversible rejection in 5 cases. In the decade from 1985 to 1995, only 14 patients had irreversible rejection that often was associated with other complications such as ischemic cholangitis. Furthermore, the rate of irreversible rejection decreased dramatically. Thus, although 5 deaths were caused by irreversible rejection, none occurred since March 1991, and of the 16 retransplantations for irreversible rejection, only one needed to be performed during these last 4 years. The disappearance of irreversible rejection, which can be described as the "vanishing vanishing bile duct syndrome," must be considered when new immunosuppressants are tested, because graft loss and death from rejection are no longer suitable criteria.

Cytomegalovirus infection does not increase the risk of vanishing bile duct syndrome after liver transplantation

Cytomegalovirus (CMV) infection and HLA-DR sharing have been reported to be associated with the development of vanishing bile duct syndrome (VBDS) after liver transplantation. We retrospectively analyzed the importance of these risk factors for VBDS in 126 consecutive recipients of a first transplant. In contrast to previous studies, CMV was monitored strictly using the antigenemia assay, a quantitative marker of the viral load. Patient and graft survival were comparable in patients with and without CMV infection. The incidence of VBDS was low, regardless of the CMV infection status or degree of HLA-DR sharing. Improvements in the early diagnosis and treatment of CMV infection may have eliminated its negative influence on graft survival.

Hepatitis C virus infection as a possible risk factor for ductopenic rejection (vanishing bile duct syndrome) after liver transplantation

Irreversible ductopenic rejection (DR) after orthotopic liver transplantation (OLT) is a major cause of late hepatic allograft failure. A variety of risk factors for DR have been postulated, but they are controversial. All transplant recipients at our institution with graft survival of more than 1 month (n = 120) were examined retrospectively with a view to possible risk factors for DR. These factors included age, sex, underlying liver disease, hepatitis B and C infections, donor-recipient CMV status, post-OLT CMV infections, immunosuppressive regimen, ABO blood type, and HLA class I and class II mismatches. Statistical analysis was performed with the univariate chi-square test or the two-tailed Fischer's exact test. Ten patients (8.3%) developed DR. Seventeen patients had HCV infections after OLT. In this group, the incidence of DR was highest (4 of 17, or 23.5%). This was significantly higher than for all other OLT groups (6 of 103 patients, or 5.8%; P < 0.03). The other factors analyzed did not reach statistical significance, including those that other authors found important for the development of DR. It may well be that hepatitis C infection predisposes one to the development of DR after OLT.

Sex mismatch as a risk factor for chronic rejection of liver allografts

Chronic irreversible rejection is a major cause of graft loss and retransplantation after orthotopic liver allotransplantation. To identify risk factors we retrospectively analysed 423 adult consecutive primary liver allograft recipients. The endpoint of the study was graft failure due to chronic rejection leading either to retransplantation or death. Chronic rejection developed in 22 (5.2%) patients. Pretransplant diagnosis of primary biliary cirrhosis or autoimmune hepatitis, recipient age less than 30 years, 1 or more episodes of acute cellular rejection, and transplantation of an organ from cytomegalovirus (CMV). IgG positive donor to an IgG negative recipient were identified as risk factors for chronic rejection. Transplantation of a liver from a male donor into a female recipient was also associated with an increased probability of chronic rejection. By logistic regression analysis, the probability of chronic rejection was predicted by: sex and cytomegalovirus match of donor and recipient, the presence of acute rejection, recipient age, transplantation for autoimmune hepatitis or primary biliary cirrhosis, and recipients receiving no azathioprine during the third month after transplantation. Sensitisation to antigens expressed by bile-duct epithelium as in primary biliary cirrhosis or exposure to donor bile-duct minor histocompatibility antigens, such as the male sex related H-Y antigen, may provide an explanation. More selective allocation of donor organs may allow a reduction in the incidence of ductopaenic rejection and graft loss.

Hepatitis C virus infection as a possible risk factor for ductopenic rejection (vanishing bile duct syndrome) after liver transplantation

Irreversible ductopenic rejection (DR) after orthotopic liver transplantation (OLT) is a major cause of late hepatic allograft failure. A variety of risk factors for DR have been postulated, but they are controversial. All transplant recipients at our institution with graft survival of more than 1 month (n = 120) were examined retrospectively with a view to possible risk factors for DR. These factors included age, sex, underlying liver disease, hepatitis B and C infections, donor-recipient CMV status, post-OLT CMV infections, immunosuppressive regimen, ABO blood type, and HLA class I and class II mismatches. Statistical analysis was performed with the univariate chi-square test or the two-tailed Fischer's exact test. Ten patients (8.3%) developed DR. Seventeen patients had HCV infections after OLT. In this group, the incidence of DR was highest (4 of 17, or 23.5%). This was significantly higher than for all other OLT groups (6 of 103 patients, or 5.8%; P < 0.03). The other factors analyzed did not reach statistical significance, including those that other authors found important for the development of DR. It may well be that hepatitis C infection predisposes one to the development of DR after OLT.

CMV-induced class II antigen expression in various rat organs

Cytomegalovirus (CMV) is thought to trigger acute or chronic allograft rejection by inducing the expression of MHC class II antigens in the graft. This induction may be mediated by gamma-interferon or directly by CMV. In this study, we have investigated which structures in the rat kidney, liver, and heart are responsive to CMV-induced class II expression in vivo. Rats were infected with rat CMV, the organs were harvested during the acute phase of infection, and the virus was demonstrated by culture from each organ. Direct CMV antigen detection was performed on frozen sections to demonstrate the detailed localization of CMV in the organs. In the kidney, CMV antigens were found in the vascular endothelium, in tubular cells, and scattered in the glomeruli. In the liver, the vascular structures and parenchyma contained CMV antigens. In the heart, CMV antigens were seen only in the capillary endothelium. Class II antigen expression was demonstrated by a monoclonal antibody and immunoperoxidase techniques. The induction of class II molecules was recorded in exactly the same cellular structures as those in which CMV antigens were detected.

Hepatic allograft rejection: new developments in terminology, diagnosis, prevention, and treatment

Hepatic allograft rejection remains a major cause of morbidity related to the need for increased immunosuppression and continues to be a principal cause of late failure of the graft. Hepatic allograft rejection is defined on the basis of morphologic findings; cellular rejection is defined as portal or periportal hepatitis with nonsuppurative cholangitis or endotheliitis (or both), and ductopenic rejection is defined as loss of interlobular and septal bile ducts, typically in at least 50% of the portal tracts. The overall incidence of episodes of cellular rejection, which usually occur within the first 2 weeks after liver transplantation, varies from 50 to 100%. Ductopenic rejection occurs in approximately 8% of patients who undergo initial liver transplantation and is usually diagnosed between 6 weeks and 6 months after transplantation. Induction and maintenance immunosuppression with triple-drug (cyclosporine, prednisone, and azathioprine) therapy and other combinations that include antilymphocyte preparations, however, has decreased the incidence of both cellular and ductopenic rejection. In patients experiencing episodes of cellular rejection, high-dose intravenously administered corticosteroid therapy yields the best response and is associated with a lower incidence of ductopenic rejection than is low-dose and orally administered corticosteroid therapy. The correlation between degree of biochemical liver dysfunction and presence of histologic rejection is minimal early after transplantation. Histologic severity of rejection, however, suggests which patients will require more immunosuppression and which patients may need antilymphocyte therapy for controlling the rejection episode. With the availability of new immunosuppressive agents, distinguishing patients at high risk for rejection is important. The goals for use of new immunosuppressive agents and regimens are to improve graft and patient survival, to decrease the incidence of cellular and ductopenic rejection, and to minimize side effects and complications.