Hepatic veno-occlusive disease associated with renal transplantation and azathioprine therapy

Management of hepatic vein occlusive disease after liver transplantation: A case report with literature review

RATIONALE

Hepatic vein occlusive disease (HVOD) is a rare complication after liver transplantation, which is characterized by nonthrombotic, fibrous obliteration of the small centrilobular hepatic veins by connective tissue and centrilobular necrosis in zone 3 of the acini. HVOD after solid organ transplantation has been reported; recently, most of these reports with limited cases have documented that acute cell rejection and immunosuppressive agents are the major causative factors. HVOD is relatively a rare complication of liver transplantation with the incidence of approximately 2%.

PATIENT CONCERNS

A 59-year-old male patient with alcoholic liver cirrhosis underwent liver transplantation in our center. He suffered ascites, renal impairment 3 months after the surgery while liver enzymes were in normal range.

DIAGNOSES

Imagining and pathology showed no evidence of rejection or vessels complications. HVOD was diagnosed with pathology biopsy.

INTERVENTIONS

Tacrolimus was withdrawn and the progression of HVOD was reversed.

OUTCOMES

Now, this patient has been followed up for 6 months after discharge with normal liver graft function.

LESSONS

The use of tacrolimus in patients after liver transplantation may cause HVOD. Patients with jaundice, body weight gain, and refractory ascites should be strongly suspected of tacrolimus related HVOD.

Evaluation of azathioprine-induced cytotoxicity in an in vitro rat hepatocyte system

Azathioprine (AZA) is widely used in clinical practice for preventing graft rejection in organ transplantations and various autoimmune and dermatological diseases with documented unpredictable hepatotoxicity. The potential molecular cytotoxic mechanisms of AZA towards isolated rat hepatocytes were investigated in this study using “Accelerated Cytotoxicity Mechanism Screening” techniques. The concentration of AZA required to cause 50% cytotoxicity in 2 hrs at 37°C was found to be 400 μM. A significant increase in AZA-induced cytotoxicity and reactive oxygen species (ROS) formation was observed when glutathione- (GSH-) depleted hepatocytes were used. The addition of N-acetylcysteine decreased cytotoxicity and ROS formation. Xanthine oxidase inhibition by allopurinol decreased AZA-induced cytotoxicity, ROS, and hydrogen peroxide (H₂O₂) formation and increased % mitochondrial membrane potential (MMP). Addition of N-acetylcysteine and allopurinol together caused nearly complete cytoprotection against AZA-induced hepatocyte death. TEMPOL (4-hydroxy-2,2,6,6-tetramethylpiperidin-1-oxyl), a known ROS scavenger and a superoxide dismutase mimic, and antioxidants, like DPPD (N,N′-diphenyl-p-phenylenediamine), Trolox (a water soluble vitamin E analogue), and mesna (2-mercaptoethanesulfonate), also decreased hepatocyte death and ROS formation. Results from this study suggest that AZA-induced cytotoxicity in isolated rat hepatocytes may be partly due to ROS formation and GSH depletion that resulted in oxidative stress and mitochondrial injury.

Drug choices in autoimmune hepatitis: part B--Nonsteroids

Nonsteroidal medications, previously unfamiliar in the management of autoimmune hepatitis, can supplement or replace conventional corticosteroid regimens, especially in problematic patients. Mycophenolate mofetil is a next-generation purine antagonist that has been useful in treating patients with azathioprine intolerance. It has been less effective in salvaging patients with steroid-refractory disease. Azathioprine is the choice as a corticosteroid-sparing agent in treatment-naive patients and in individuals with corticosteroid intolerance, incomplete response and relapse after drug withdrawal. Tacrolimus is preferred over cyclosporine for recalcitrant disease because of its established preference in organ transplantation, but replacement with cyclosporine should be considered if the disease worsens on treatment. Rapamycin has antiproliferative and proapoptotic actions that warrant further study in autoimmune hepatitis. The nonstandard, nonsteroidal medications are mainly salvage therapies with off-label indications that must be used in highly individualized and well-monitored clinical situations.

Gastrointestinal complications of oncologic therapy

Gastrointestinal complications are common in patients undergoing various forms of cancer treatment, including chemotherapy, radiation therapy, and molecular-targeted therapies. Many of these complications are life-threatening and require prompt diagnosis and treatment. Complications of oncologic therapy can occur in the esophagus (esophagitis, strictures, bacterial, viral and fungal infections), upper gastrointestinal tract (mucositis, bleeding, nausea and vomiting), colon (diarrhea, graft-versus-host disease, colitis and constipation), liver (drug hepatotoxicity and graft-versus-host disease), and pancreas (pancreatitis). Treatment of the different gastrointestinal complications should be tailored to the individual patient and based on the underlying pathophysiology of the complication.

Safety issues in the management of autoimmune hepatitis

BACKGROUND

Prednisone and azathioprine are effective in the treatment of autoimmune hepatitis, but diverse side effects can diminish their net benefit.

OBJECTIVES

Describe the frequency and nature of these side effects and propose management strategies to minimize their impact.

METHODS

Pertinent articles published from 1970 to 2007 were identified by Medline search and through a personal library.

RESULTS

Medication is prematurely discontinued in 13% of patients mainly because of cosmetic changes, cytopenia, or osteopenia. Populations at high risk are the elderly, those with pre-existent co-morbidities, patients with near-zero thiopurine methyltransferase activity, individuals who are treatment-dependent, pregnant women, and asymptomatic patients who are over-treated.

CONCLUSIONS

Proper patient selection, effective pre-treatment counseling, preemptive protective measures, realistic treatment objectives, and early identification of problematic patients can reduce complications. Individualized dosing schedules and the emergence of non-steroidal medications are realistic expectations.

Vascular Toxicity of Antineoplastic Agents

Among the various deleterious effects of cancer chemotherapy, vascular toxicity is the least well recognized. This lack of recognition may be because the vasculotoxic phenomena are not unique to antineoplastic agents, can occur in patients without exposure to these agents, and the fact cancer itself may produce a hypercoagulable state. As a result, many vascular events either go unnoticed, are ignored, and/or are attributed to the underlying malignancy. Many antineoplastic therapies are associated with various vascular phenomena that range from simple phelibitis to lethal microangiopathy. Recognition of these events is important to minimize the morbidity and even prevent unnecessary deaths. Herein we review the vascular syndromes that have been reported in association with antineoplastic agents.

Hepatotoxicity of Chemotherapy

The selection of an antineoplastic regimen for an oncology patient is based first on the availability of effective drugs and then on a balancing of potential treatment-related toxicities with the patient's clinical condition and associated comorbidities. Liver function abnormalities are commonly observed in this patient population and identifying their etiology is often difficult. Immunosuppression, paraneoplastic phenomena, infectious diseases, metastases, and poly-pharmacy may cloud the picture. While criteria for standardizing liver injury have been established, dose modifications often rely on empiric clinical judgment. Therefore, a comprehensive understanding of hepatotoxic manifestations for the most common chemotherapeutic agents is essential. We herein review the hepatotoxicity of commonly used antineoplastic agents and regimens.

Review article: updates in the pathogenesis and therapy of hepatic sinusoidal obstruction syndrome

Hepatic sinusoidal obstruction syndrome is frequently linked to high-dose chemotherapy/total-body irradiation in recipients of haematopoietic stem cell transplantation, long-term use of azathioprine after organ transplantation and other chemotherapeutic agents. The incidence of hepatic sinusoidal obstruction syndrome varies from 0% to 70%, and is decreasing. Disease risk is higher in patients with malignancies, hepatitis C virus infection, those who present late, when norethisterone is used to prevent menstruation, and when broad-spectrum antibiotics and antifungals are used during and after the conditioning therapy. Hepatic sinusoidal obstruction syndrome presents with tender hepatomegaly, hyperbilirubinaemia and ascites, and diagnosis is mainly clinical (Seattle and Baltimore Criteria). Imaging excludes biliary obstruction and malignancy, but cannot establish accurate diagnosis. Hepatic sinusoidal obstruction syndrome may be prevented by avoiding the highest risk regimens, using non-myelo-ablative regimens, and reducing total-body irradiation dose. Treatment is largely symptomatic and supportive, because 70-80% of patients recover spontaneously. Tissue plasminogen activator plus heparin improves outcome in <30% of cases. Defibrotide, a polydeoxyribonucleotide, is showing encouraging results. Transjugular intrahepatic porto-systemic shunt relieves ascites, but does not improve outcome. Liver transplantation may be an option in the absence of malignancy. Prognosis is variable and depends on disease severity, aetiology and associated conditions. Death is most commonly caused by renal or cardiopulmonary failure.

Promising treatment of autoimmune hepatitis with 6-thioguanine after adverse events on azathioprine

The use of corticosteroids in autoimmune hepatitis is an established therapy. To avoid the possible serious side effects of corticosteroids, immunosuppression with azathioprine is often warranted. Azathioprine, a purine analogue, is frequently used to taper or replace corticosteroids. However, approximately 10% of the patients are intolerant to azathioprine. Alternative therapies using mycophenolate, tacrolimus, budesonide, cyclosporine and 6-mercaptopurine have been studied, with variable results. The use of 6-thioguanine, an agent more directly leading to the down-stream active metabolites of azathioprine (6-thioguanine nucleotides) in inflammatory bowel disease patients intolerant to azathioprine or 6-mercaptopurine showed conflicting results. We report three patients with autoimmune hepatitis who could not tolerate azathioprine but tolerated 6-thioguanine 0.3 milligram per kilogram daily well. All three patients improved clinically. Therapeutic drug monitoring was performed. The prospective evaluation of 6-thioguanine as a possible immunosuppressive drug in autoimmune hepatitis patients is warranted.

Scintigraphic patterns of veno-occlusive disease in liver transplantation

Venous vascular complications in liver transplant recipients are rare. Diagnosis is usually based on clinical criteria and typical findings on liver biopsy. The scintigraphic patterns of posttransplant liver veno-occlusive disease are described, and the value of follow-up studies is suggested. The authors present 2 patients who developed posttransplantation hepatic veno-occlusive disease. The first patient had a severe form of the disease and a fatal outcome. The second patient had a mild to moderate form of this disorder with complete resolution following treatment.

Toxicity of low dose azathioprine and 6-mercaptopurine in rat hepatocytes. Roles of xanthine oxidase and mitochondrial injury

BACKGROUND/AIMS

To study effects of pharmacologic concentrations of azathioprine and 6-mercaptopurine (6-MP) on rat hepatocytes.

METHODS

Hepatocytes cultured on matrigel were incubated with azathioprine or 6-MP; effects of putative protective agents were studied. Viability (LDH leakage), reduced (GSH) and oxidized glutathione (GSSG), mitochondrial (mt) GSH, ATP and ultrastructural changes were determined.

RESULTS

Azathioprine and 6-MP (0.5-5 micromol/l) reduced viability 5-34% at day 1 and 42-92% by day 4. Allopurinol (20 microM) (xanthine oxidase inhibitor) and 2 mM Trolox (vitamin E analog) together provided near complete protection. During culture with azathioprine, GSSG increased before cell death and there was a disproportionate reduction of mtGSH and ATP, together with ultrastructural abnormalities in mitochondria. All changes were prevented by allopurinol and trolox. Discontinuation of 1 micromol/l azathioprine restored ATP levels and arrested cell injury, while culture in glucose-enriched media augmented ATP levels and ameliorated cell death.

CONCLUSIONS

Clinically relevant concentrations of azathioprine and 6-MP are toxic to rat hepatocyte cultures by a mechanism that involves oxidative stress, mitochondrial injury and ATP depletion. This can lead to irreversible de-energization and cell death by oncosis (necrosis).

Remission maintenance by tioguanine in chronic active Crohn's disease

BACKGROUND

Tioguanine may offer an alternative for immunosuppression in chronic active Crohn's disease. Recently, we have shown that tioguanine is effective in inducing rapid remission.

AIM

To evaluate the role of tioguanine in the maintenance of remission in chronic active Crohn's disease.

METHODS

A follow-up study was performed to investigate the long-term efficacy and safety of and tolerance to tioguanine in chronic active Crohn's disease. Sixteen patients who had successfully received 6-tioguanine for remission induction were enrolled. The reasons for immunosuppressive therapy were steroid dependence (n = 10), steroid refractoriness (n = 6) and intolerance (n = 6) or refractoriness (n = 1) to azathioprine. After remission induction therapy for 6 months, patients were treated for another 6 months with a daily dose of 20-40 mg tioguanine. Primary outcomes were remission (Crohn's disease activity index < 150) and complete steroid reduction in steroid-dependent patients at 12 months. Laboratory controls of white blood count and liver enzymes, as well as erythrocyte tioguanine nucleotide levels, were performed regularly.

RESULTS

After 12 months of treatment, 14 of 16 (88%) patients were in remission, and 12 of these were completely free of systemic steroids. Adverse events during maintenance therapy included photosensitivity (one patient), minor viral infections (one), headache (four) and mild alopecia (one). One patient developed elevated liver enzymes, splenomegaly and thrombocytopenia, indicative of nodular regenerative hyperplasia of the liver.

CONCLUSIONS

In responders to tioguanine, the drug appears to be very effective in maintaining remission of chronic active Crohn's disease. Unfortunately, long-term hepatotoxicity seems to be an unpredictable and potentially severe adverse drug reaction. Therefore, to date, tioguanine cannot be recommended for general use outside clinical trials.

Hepatic veno-occlusive disease (sinusoidal obstruction syndrome) after hematopoietic stem cell transplantation

Hepatic veno-occlusive disease (VOD), increasingly referred to as sinusoidal obstruction syndrome, is a well-recognized complication of hematopoietic stem cell transplantation and contributes to considerable morbidity and mortality. In the Western Hemisphere, VOD, classified as a conditioning-related toxicity, is most commonly caused by stem cell transplantation. VOD has been described after all types of stem cell transplantation, irrespective of the stem cell source, type of conditioning therapy, or underlying disease. Recognition of this disease in the posttransplantation setting remains a challenge in the absence of specific diagnostic features because many other more common conditions can mimic it. Limited therapeutic or preventive strategies are currently available for the management of VOD. In this review, we provide a comprehensive account of the pathophysiology of this disease as we understand it today, risk factors for its development, and the current state of knowledge regarding preventive and therapeutic options.

A comparison of hepatoprotective activities of aminoguanidine and N-acetylcysteine in rat against the toxic damage induced by azathioprine

Azathioprine (AZA) is an important drug used in the therapy of autoimmune system disorders. It induces hepatotoxicity that restricts its use. The rationale behind this study was the proven efficacy of N-acetylcysteine (NAC; a replenisher of sulfhydryls) and reports on the antioxidant potential of aminoguanidine (AG; an iNOS inhibitor), that might be useful to protect against the toxic implications of AZA. AG (100 mg/kg; i.p.) or NAC (100 mg/kg; i.p.) were administered to the Wistar male rats for 7 days and after that AZA (15 mg/kg, i.p.) was given as a single dose. This caused an increase in the activity of hepatic aminotransferases (AST and ALT) in the serum 24 h after AZA treatment. AZA (7.5 or 15 mg/kg, i.p.) also caused an increase in rat liver lipid peroxides and a lowering of reduced glutathione (GSH) contents. In the other part of experiment, protective effects of AG and NAC were observed on AZA induced hepatotoxicity. NAC significantly protected against the toxic effects produced by AZA. Pretreatment with NAC prevented any change in the activities of both the aminotransferases after AZA. This pretreatment also resulted in a significant decline in the contents of lipid peroxides and a significant elevation in GSH level was evident after AZA treatment. In the group with AG pretreatment the activities of AST and ALT did not increase significantly after AZA when compared to control. However, the lipid peroxides and GSH levels did not have any significant difference when compared to AZA group. These observations also indicate that the improvement in the GSH levels by NAC is the most significant protective mechanism rather than any other mechanistic profile. The protective effect of AG against the enzyme leakage seems to be through the liver cell membrane permeability restoration and is independent of any effects on liver GSH contents.

Hepatic circulatory diseases associated with chronic myeloid disorders

These liver diseases are diseases of the hepatic circulation. Myeloproliferative disorders are among the most common prothrombotic disorders that lead to Budd-Chiari syndrome and PVT. SOS, previously known as hepatic veno-occlusive disease, is mainly seen in North America and Western Europe as a complication of the conditioning regimen for hematopoietic stem cell transplantation. SOS is caused by damage to SECs, and the initiating circulatory blockage occurs because of the embolism of sinusoidal lining cells. Myeloproliferative disorders are an uncommon cause of NRH, which is believed to be caused by uneven perfusion of the liver at the venous or sinusoidal level. Peliosis hepatis is believed to result from damage to SECs and is seen mainly in immunosuppressed patients, patients with a wasting illness, or patients with a drug toxicity.

Defibrotide for the treatment of veno-occlusive disease after liver transplantation

BACKGROUND

Veno-occlusive disease (VOD) after liver transplantation is associated with acute rejection and poor outcome. The use of antithrombotic and thrombolytic agents is limited by their toxicity. Defibrotide is a polydeoxyribonucleotide with thrombolytic and antithrombotic properties and no systemic anticoagulant effect.

METHODS

Defibrotide, 35-40 mg/kg/day, was administered intravenously for 21 days on a compassionate-use basis to two patients aged 66 and 49 years. VOD had developed 6 weeks and 4 months after orthotopic liver transplantation for hepatitis C and hepatitis B infection, respectively. VOD was diagnosed clinically by findings of weight gain (8.5% and 16%), ascites, jaundice (serum bilirubin 5.4 mg/dl and 21.7 mg/dl), and severe coagulopathy (in one patient), and histologically by the presence of hemorrhagic centrilobular necrosis and fibrous stenosis of the hepatic venules. One of the patients had received azathioprine as part of the immunosuppressive regimen. There was no evidence of acute cellular rejection histologically.

RESULTS

After 3 weeks of defibrotide administration, the first patient showed complete clinical resolution of the VOD, and serum bilirubin level normalized. He is alive 6 months after transplantation. The second patient, treated at a later stage of disease, showed marked improvement in the coagulopathic state, but there was no resolution of the VOD. He died 2 months later of multiorgan failure due to Escherichia coli sepsis. Neither patient had side effects from the drug.

CONCLUSIONS

Defibrotide is a promising drug for the treatment of VOD after liver transplantation and needs to be evaluated in large, prospective studies.

Hepatotoxicity of chemotherapy

After assessment of tumor histology, the next important factor to consider in the selection of a chemotherapy regime is organ function. Patients who are to receive chemotherapy require careful assessment of liver function prior to treatment to determine which drugs may not be appropriate, and which drug doses should be modified. Following therapy abnormalities of liver function tests may be due to the therapy rather than to progressive disease, and this distinction is of critical importance. Furthermore, not all abnormalities in liver function are due to the tumor or its treatment, and other processes, such as hepatitis, must be kept in mind. This article reviews the hepatic toxicity of chemotherapeutic agents, and suggests dose modifications based upon liver function abnormalities. Emphasis is placed on agents known to be hepatotoxic, and those agents with hepatic metabolism.

Veno-occlusive disease, nodular regenerative hyperplasia and hepatocellular carcinoma after azathioprine treatment in a patient with ulcerative colitis

We report the case of a 66-year-old male with ulcerative colitis diagnosed in 1987, who had been treated with azathioprine (AZA) for the past two years (average dose about 1.6 mg/kg/day). In May 1999 he presented with painless jaundice, fatigue and recent weight loss. Cholestatic enzymes were elevated, alpha-fetoprotein was normal and hepatitis B/C serology negative. After diagnosis of veno-occlusive disease (VOD) and hepatocellular carcinoma (HCC) via biopsy, tumour resection was performed. The histology was typical for a well-differentiated HCC with trabecular and pseudoglandular structures. Neighbouring liver tissue was atrophic, with nodular regenerative hyperplasia (NRH), peliosis-like sinusoidal ectasias and intra-sinusoidal accumulation of blood, associated with peri-sinusoidal fibrosis. Although none of the well-established risk factors for HCC such as cirrhosis, hepatitis B/C, metabolic liver disease or toxins were present, this patient developed HCC. This and previous reports suggest that NRH and/or VOD associated with AZA represent a risk factor for HCC. AZA should therefore not only be stopped in patients with NRH/VOD but patients should also be screened for HCC.

Recommendations for the outpatient surveillance of renal transplant recipients. American Society of Transplantation

Many complications after renal transplantation can be prevented if they are detected early. Guidelines have been developed for the prevention of diseases in the general population, but there are no comprehensive guidelines for the prevention of diseases and complications after renal transplantation. Therefore, the Clinical Practice Guidelines Committee of the American Society of Transplantation developed these guidelines to help physicians and other health care workers provide optimal care for renal transplant recipients. The guidelines are also intended to indirectly help patients receive the access to care that they need to ensure long-term allograft survival, by attempting to systematically define what that care encompasses. The guidelines are applicable to all adult and pediatric renal transplant recipients, and they cover the outpatient screening for and prevention of diseases and complications that commonly occur after renal transplantation. They do not cover the diagnosis and treatment of diseases and complications after they become manifest, and they do not cover the pretransplant evaluation of renal transplant candidates. The guidelines are comprehensive, but they do not pretend to cover every aspect of care. As much as possible, the guidelines are evidence-based, and each recommendation has been given a subjective grade to indicate the strength of evidence that supports the recommendation. It is hoped that these guidelines will provide a framework for additional discussion and research that will improve the care of renal transplant recipients.

Fatal course of veno-occlusive disease of the liver (endophlebitis hepatica obliterans) in a preterm infant

We describe the fatal course of a preterm infant of 34 weeks' gestation with veno-occlusive disease of the liver and refractory ascites. Despite aggressive medical management, the baby died twenty-two hours post partum because of cerebral haemorrhage before potentially life-saving organ transplantation could take place. At autopsy, paucity of lymphoid tissue in lymph nodes, thymus, spleen, and gastrointestinal tract were also seen. To our knowledge, this is the youngest infant with veno-occlusive disease of the liver reported in the literature.

"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.

Drug therapy in the management of type 1 autoimmune hepatitis

Prednisone alone or in combination with azathioprine is the treatment of choice for severe type 1 autoimmune hepatitis. The combination regimen is preferred, especially in the elderly, because of a lower incidence of corticosteroid-related complications. Only patients with sustained severe laboratory abnormalities, bridging necrosis or multilobular necrosis on histological assessment, and/or incapacitating symptoms, have absolute indications for treatment based on controlled clinical trials. The institution of therapy must be individualised in other patients, based mainly on symptoms and disease behaviour. Serum aspartate aminotransferase and gamma-globulin levels are the most useful indices to monitor during therapy. Liver tissue examination is the best method of evaluating completeness of response. Most patients enter remission, but relapse occurs in 50 to 86% after drug withdrawal. Maintenance therapy with low dosages of prednisone or azathioprine can be used long term in patients who have relapsed repeatedly. Inability to achieve remission after 3 years (incomplete response), deterioration during therapy (treatment failure) and drug toxicity are unsatisfactory responses that warrant alternative strategies. Liver transplantation is effective in managing decompensated disease, but recurrence of autoimmune hepatitis after transplantation is possible. Tacrolimus and budesonide are promising new drugs.

Pharmacology of immunosuppressive medications used in renal diseases and transplantation

As understanding of the molecular basis for the immune response has expanded rapidly, so have the possibilities for designing therapeutic interventions that are more effective, more specific, and safer than current treatment options. The promise of therapeutic advances in the future is based on the rapidly expanding insights into the pathogenesis of abnormal immunologic reactions. Nowhere is the understanding of molecular mechanisms, pathophysiology, and targeted therapy more relevant than in the field of renal transplantation, which makes up much of the clinical database for the use of immunosuppressive therapy for renal disease. Despite the recent advances in basic immunology, clinical validation of new agents and approaches is lacking for most drugs at present. This review will focus in the pharmacology of agents used in the therapy of immunologic renal disease and in renal transplantation. It should be recognized that clinical pharmacology and experience with newer agents is limited, and potential utility is based largely on experimental data.

Budd-Chiari syndrome

Budd-Chiari syndrome is the generic term for different forms of hepatic venous outflow obstruction resulting in a clinical picture of portal hypertension and hepatomegaly. Three levels of venous outflow obstruction may be recognized, affecting respectively the small intrahepatic (IVC). Each level of obstruction is related to a different aetiology. Clinical manifestations range from mild symptoms to acute or chronic end-stage liver disease. Treatment is surgical in the great majority of patients. Occlusion of the IVC may be treated by removal of the caval obstruction in selected patients. Hepatic outflow obstruction may be circumvented by different forms of shunting from the portal or upper mesenteric vein to the IVC or right atrium, depending on the level of obstruction and the difference in venous pressure. For the rare patient presenting with acute or chronic end-stage liver failure, hepatic transplantation may be a life-saving procedure.

Value of liver biopsy in the evaluation and management of chronic liver disease in renal transplant recipients

PURPOSE

Liver disease is a frequent complication in renal transplant recipients. To understand the nature and progression of hepatic disease in these patients, we performed percutaneous biopsies in 77 subjects who had chronic liver dysfunction in the posttransplant period. The purpose of the present investigation is to delineate the morphologic spectrum of chronic liver disease in the renal allograft recipients and to characterize the clinical and histologic progression of each of the different morphologic forms.

PATIENTS AND METHODS

Between 1971 and 1990, 915 patients received renal transplants at the Hennepin County Medical Center, Minneapolis, Minnesota. One hundred nineteen (13%) of them had abnormal liver function that persisted for longer than 6 months. Percutaneous liver biopsies were performed in 77 of these patients, but adequate tissue for histologic evaluation was available in only 72. After the biopsy, the clinical and histologic course of each subject was monitored in relation to the baseline hepatic morphology. To assess the predictive value of serum enzymes in diagnosing the histologic lesions, the level of serum enzymes at the time of the biopsy was correlated with the morphologic diagnosis. In addition, several clinical, biochemical, etiologic, and histologic variables were screened for their association with histologic progression to liver cirrhosis.

RESULTS

The morphologic diagnosis in the 72 specimens evaluated at baseline was as follows: fat metamorphosis in 8 (11%), chronic persistent hepatitis in 20 (28%), early chronic active hepatitis in 20 (28%), advanced chronic active hepatitis in 15 (21%), and hemosiderosis in 9 (12%). There was no statistical correlation between the serum enzyme levels and the histologic diagnosis. During a mean follow-up of 5.7 +/- 3.9 years, clinical progression to hepatic failure and death occurred in 35% of patients with early chronic active hepatitis, 55% with hemosiderosis, and 60% with advanced chronic active hepatitis. None of the patients with the morphologic diagnosis of fat metamorphosis or chronic persistent hepatitis died as a consequence of hepatic failure. Follow-up liver specimens were obtained in 34 (47%) of the original 72 subjects after a mean interval of 4.5 +/- 4.3 years. Of the 15 patients with the initial diagnosis of early chronic active hepatitis, 9 (60%) showed morphologic transition to advanced chronic active hepatitis, and in 1 of the 5 patients with hemosiderosis (20%), the lesion had resolved after successive phlebotomies. During the follow-up, 60% with early chronic active hepatitis (9 of 14), 66% with hemosiderosis (2 of 3), and 100% with advanced chronic active hepatitis (4 of 4) showed histologic progression to liver cirrhosis. On the contrary, no morphologic alterations were observed in the follow-up specimens of patients with fat metamorphosis or chronic persistent hepatitis. Of the different variables screened for their association with histologic progression, older age at transplant, female sex, and morphologic diagnosis of advanced chronic active hepatitis were found to be significant.

CONCLUSION

Histologic diagnosis can be a useful marker in predicting the course of chronic liver disease after renal transplantation. Liver biopsy should be incorporated into the evaluation and management of chronic liver disease in renal transplant recipients.

Idiopathic portal hypertension in a renal transplant patient after long-term azathioprine therapy

We report the case of a patient with renal insufficiency who was admitted for the evaluation of splenomegaly. He had received a kidney allograft 6 1/2 years ago. Treatment with azathioprine and prednisolone for immunosuppression had been discontinued 1 year before admission. The underlying cause of the splenomegaly appeared to be an idiopathic portal hypertension. Until now, this disease has been described in only 13 kidney transplant patients receiving long-term immunosuppressive therapy with azathioprine. For the first time we demonstrate that azathioprine can cause this chronic liver disease even if the drug has been withdrawn some time before. Therefore, the indication for azathioprine must be considered very carefully.

Azathioprine hepatotoxicity after liver transplantation

We report the first two cases of apparent azathioprine hepatotoxicity occurring after liver transplantation. The two patients exhibited jaundice, elevated serum transaminase activities and histopathological features of sinusoidal congestion and centrilobular hepatocellular degeneration 17 and 61 days after transplantation. After withdrawal of azathioprine, liver test results improved immediately in both patients. Recurrence of liver injury after another challenge with azathioprine was seen in the first case. Previously, fatal venoocclusive disease occurring after kidney transplantation had been attributed to azathioprine. Irreversible venoocclusive disease and the reversible hepatotoxicity described in this report (i.e., sinusoidal congestion with centrizonal necrosis) most likely represent different stages of hepatic endotheliitis caused by azathioprine. Thus early diagnosis of azathioprine hepatotoxicity is of great importance.

Prophylactic heparin does not prevent liver veno-occlusive disease following autologous bone marrow transplantation

Veno-occlusive disease (VOD) is a major cause of toxic death after autologous bone marrow transplantation (ABMT). We studied the potential role of continuous administration of low-dose heparin for VOD prevention in 234 consecutive patients who underwent ABMT in our institution. The population consisted of 98 patients autografted before October 1984 who did not receive heparin, and a series of 136 patients autografted from October 1984 to March 1989 containing 98 patients included in a randomized trial comparing heparin administration (n = 52) vs no heparin (n = 46), and an additional group of 38 patients who received non-randomized heparin in view of high-risk criteria to develop VOD (n = 31) or other reasons unrelated to VOD (n = 7). Overall, 90 patients (38%) received heparin and 144 (62%) did not. The global incidence of VOD was 13/234 (5-5%). Heparin did not reduce the risk of VOD in all subgroups studied. In particular, in the randomized trial, the incidence of VOD was 2.2% in the group without heparin vs 7-7% in the group receiving heparin. We analyzed in depth the 13 patients who developed VOD and we compared them to a control group of 13 patients pair-matched for age, sex, diagnosis and preparative regimen, who did not develop VOD. We found that abnormal LFT before ABMT predisposed patients to VOD; refractoriness to platelet transfusion was observed in 85% of the patients in the VOD group vs 15% in the control group (p less than 0.05). VOD patients had an increased requirement for red cells and platelet transfusions, a lower recovery (R less than 25%) after the second and third platelet transfusion, and shorter intervals separating the first four platelet transfusions. Further, the platelet reconstitution after ABMT in the VOD group was slower in comparison to the control group (p less than 0.01). Again, in this pair-matched analysis continuous infusion of low-dose heparin did not prevent VOD.

Hepatitis C virus infection among kidney transplant recipients

The extent of hepatitis C virus (HCV) infection among kidney recipients was investigated in 67 patients by testing for anti-HCV paired serum samples, collected at time of transplantation and during follow-up (average 32 +/- 20 months). Prevalence of anti-HCV at transplant time was 48%, and was related to the time on dialysis and to the amount of blood transfusions. Following transplantation, nine (28%) seropositive patients lost anti-HCV and five (14%), previously seronegative, seroconverted. Anti-HCV was found to be positive in 92% of the patients with chronic liver disease who were on hemodialysis, but in 56% in kidney recipients with chronic hepatitis. Anti-HCV was positive in 50% of patients with resolving hepatitis before transplantation, but only in 21% of those with acute hepatitis following transplantation. This study confirms the high risk of HCV infection among hemodialysis and kidney recipient populations, and also that HCV is closely related with the length of time the patient is on hemodialysis as well as the number of blood units transfused. HCV is the main cause of acute and chronic liver disease in hemodialysis patients and of chronic liver disease in kidney recipients, but does not clearly influence the survival of the allograft nor that of patients.

Increased infection rate in diabetic dialysis patients exposed to cocaine

Three hundred ninety-seven insulin-dependent diabetic dialysis patients were screened by nursing staff for analgesic-seeking behavior. Thirty-eight patients were identified and classified as prescription abusers (n = 26) or illicit drug users (n = 12). The nine cocaine users, when compared with 14 insulin-dependent diabetics on dialysis matched by protocol, were found to be similar in terms of diabetic retinopathy and metabolic neuropathy. Although statistically not significant, cerebrovascular and cardiovascular complications were more common in the study group. Gastroenteropathy with malnutrition was more common the study group (P less than 0.025). Infection rate and severity were markedly worse in the cocaine group: bacterial cellulitis, sepsis, and abscess each increased greater than fourfold. All the visceral infections were in the cocaine-using group. Hepatitis viral antigen and antibody was increased 10-fold in the cocaine users. Recommendations for management of dialysis patients with analgesic-seeking behavior are formulated in light of these findings.

[Peliosis hepatis in dermatomyositis treated with azathioprine and corticoids]

We report a case of peliosis hepatis in a 47-year old male patient with dermatomyositis treated with azathioprine and corticosteroids. Three months after the combined treatment was initiated, the patient developed right thoracic herpes zoster, agranulocytosis and liver enlargement with signs of portal hypertension. Needle biopsy of the liver revealed peliosis. Azathioprine was withdrawn. The clinical and laboratory abnormalities disappeared progressively. The main causes of peliosis hepatis are considered. Up to now, azathioprine had been held responsible for peliosis hepatis only in renal transplant recipients.

Venoocclusive lesions of the central veins and portal vein radicles secondary to intraarterial 5-fluoro-2'-deoxyuridine infusion

Venoocclusive disease is characterized by the occurrence of occlusive lesions of the central and subhepatic veins, usually involving the liver in a diffuse fashion. We report a case showing venoocclusive lesions of the central veins and the portal vein radicles affecting only a portion of the left lobe of the liver following intraarterial 5-fluoro-2'-deoxyuridine therapy for metastatic adenocarcinoma of the colon. Possible mechanisms and the significance of venoocclusive lesions of portal vein radicles are discussed.

Drug-induced liver disease

The relative importance of drug-induced liver disease assumes much significance in certain groups of patients such as the elderly. The majority of cases occur as unexpected reactions to a therapeutic dose of a drug. Factors affecting susceptibility to drug-induced liver disease are diverse and are discussed in this article.

Azathioprine induced hepatic veno-occlusive disease in rheumatoid arthritis

A patient with rheumatoid arthritis developed hepatic veno-occlusive disease following the use of azathioprine. Although azathioprine induced veno-occlusive disease is suspected to occur more frequently in patients with autoimmune dysfunction, it has not previously been reported as a complication of treatment in rheumatoid arthritis. The mechanism responsible for this condition remains unknown.

Drug-induced vascular and sinusoidal lesions of the liver

Drugs can induce various vascular and sinusoidal lesions of the liver, in particular hepatic vein thrombosis, veno-occlusive disease, sinusoidal dilatation, peliosis hepatis, hepatoportal sclerosis and angiosarcoma. None of these lesions is specific of drug-induced injury and all of them can be determined by causes other than drugs. However, for one of these lesions, veno-occlusive disease, chemotherapy (and/or irradiation) represents the main aetiology.

Veno-occlusive disease of the liver following chemotherapy with mitomycin C and doxorubicin

A 54-year-old woman with metastatic breast cancer developed veno-occlusive disease of the liver following chemotherapy with mitomycin C and doxorubicin. The dose of mitomycin C received by this patient was much lower than that previously described to cause this complication. As both these drugs are used widely physicians should be aware of this complication.