Protocol for a randomized controlled multicenter trial assessing the efficacy of leuprorelin for severe polycystic liver disease: the AGAINST-PLD study

Background

In patients with severe polycystic liver disease (PLD), there is a need for new treatments. Estrogens and possibly other female sex hormones stimulate growth in PLD. In some patients, liver volume decreases after menopause. Female sex hormones could therefore be a target for therapy. The AGAINST-PLD study will examine the efficacy of the GnRH agonist leuprorelin, which blocks the production of estrogen and other sex hormones, to reduce liver growth in PLD.

Methods

The AGAINST-PLD study is an investigator-driven, multicenter, randomized controlled trial. Institutional review board (IRB) approval was received at the University Medical Center of Groningen and will be collected in other sites before opening these sites. Thirty-six female, pre-menopausal patients, with a very large liver volume for age (upper 10% of the PLD population) and ongoing liver growth despite current treatment options will be randomized to direct start of leuprorelin or to 18 months standard of care and delayed start of leuprorelin. Leuprorelin is given as 3.75 mg subcutaneously (s.c.) monthly for the first 3 months followed by 3-monthly depots of 11.25 mg s.c. The trial duration is 36 months. MRI scans to measure liver volume will be performed at screening, 6 months, 18 months, 24 months and 36 months. In addition, blood will be drawn, DEXA-scans will be performed and questionnaires will be collected. This design enables comparison between patients on study treatment and standard of care (first 18 months) and within patients before and during treatment (whole trial). Main outcome is annualized liver growth rate compared between standard of care and study treatment. Secondary outcomes are PLD disease severity, change in liver growth within individuals and (serious) adverse events. The study is designed as a prospective open-label study with blinded endpoint assessment (PROBE).

Discussion

In this trial, we combined the expertise of hepatologist, nephrologists and gynecologists to study the effect of leuprorelin on liver growth in PLD. In this way, we hope to stop liver growth, reduce symptoms and reduce the need for liver transplantation in severe PLD.

Trial registration Eudra CT number 2020-005949-16, registered at 15 Dec 2020. https://www.clinicaltrialsregister.eu/ctr-search/search?query=2020-005949-16.

Immediate impact of COVID-19 on transplant activity in the Netherlands

The rapid emergence of the COVID-19 pandemic is unprecedented and poses an unparalleled obstacle in the sixty-five year history of organ transplantation. Worldwide, the delivery of transplant care is severely challenged by matters concerning - but not limited to - organ procurement, risk of SARS-CoV-2 transmission, screening strategies of donors and recipients, decisions to postpone or proceed with transplantation, the attributable risk of immunosuppression for COVID-19 and entrenched health care resources and capacity. The transplant community is faced with choosing a lesser of two evils: initiating immunosuppression and potentially accepting detrimental outcome when transplant recipients develop COVID-19 versus postponing transplantation and accepting associated waitlist mortality. Notably, prioritization of health care services for COVID-19 care raises concerns about allocation of resources to deliver care for transplant patients who might otherwise have excellent 1-year and 10-year survival rates. Children and young adults with end-stage organ disease in particular seem more disadvantaged by withholding transplantation because of capacity issues than from medical consequences of SARS-CoV-2. This report details the nationwide response of the Dutch transplant community to these issues and the immediate consequences for transplant activity. Worrisome, there was a significant decrease in organ donation numbers affecting all organ transplant services. In addition, there was a detrimental effect on transplantation numbers in children with end-organ failure. Ongoing efforts focus on mitigation of not only primary but also secondary harm of the pandemic and to find right definitions and momentum to restore the transplant programs.

Sofosbuvir Add-on to Ribavirin Treatment for Chronic Hepatitis E Virus Infection in Solid Organ Transplant Recipients Does Not Result in Sustained Virological Response

Ribavirin is effective for treating immunocompromised patients with chronic hepatitis E virus infection. However, ribavirin treatment is not always successful. We describe 3 solid organ transplant recipients treated with sofosbuvir and ribavirin after failing ribavirin monotherapy. Complete elimination of hepatitis E virus could not be achieved.

Plasminogen Activator Inhibitor 1: Biosynthesis and mRNA Level Are Increased by Insulin in Cultured Human Hepatocytes

Clinical studies have shown that plasma insulin levels are closely related to plasma plasminogen activator inhibitor 1 (PAI-1) levels. To investigate a possible involvement of hepatocytes we have studied the effect of insulin on PAI-1 production by primary cultures of human hepatocytes. We have isolated human hepatocytes from seven left liver lobes. PAI-1 activity measured in 24 hours conditioned medium varied considerably between the various hepatocyte preparations (from 2.9 to 8.5 units per 5 cm2of cells) possibly as a result of interindividual variability in basal PAI-1 production by hepatocytes from different donors. In all cases, however, the relative extent, time profile and dose-dependency of the insulin-induced increase in PAI-1 synthesis were consistent. Up to about 7 nM, insulin dose-dependently increased both PAI-1 activity and PAI-1 antigen production. The increase in PAI-1 synthesis became measurable between 4 and 8 hours after addition of the hormone, and maximally reached twofold control values. The increase in PAI-1 synthesis could be fully explained by a concomitant increase in PAI-1 mRNA levels. The effect of insulin seems fairly specific for the synthesis of PAI-1: overall protein synthesis and mRNA levels of some control proteins (albumin and fibrinogen) did not markedly change after insulin addition. These results, obtained with primary cultures of human hepatocytes, are fully comparable with those obtained with the hepatocellular carcinoma cell line Hep G2. They strengthen the suggestion that the elevated level of PAI-1 in high insulin plasma might be the result of increased hepatic synthesis of PAI-1.

Dual hypothermic oxygenated machine perfusion in liver transplants donated after circulatory death

Background

Experimental studies have suggested that end‐ischaemic dual hypothermic oxygenated machine perfusion (DHOPE) may restore hepatocellular energy status and reduce reperfusion injury in donation after circulatory death (DCD) liver grafts. The aim of this prospective case–control study was to assess the safety and feasibility of DHOPE in DCD liver transplantation.

Methods

In consecutive DCD liver transplantations, liver grafts were treated with end‐ischaemic DHOPE. Outcome was compared with that in a control group of DCD liver transplantations without DHOPE, matched for donor age, donor warm ischaemia time, and recipient Model for End‐stage Liver Disease (MELD) score. All patients were followed for 1 year.

Results

Ten transplantations involving liver grafts treated with DHOPE were compared with 20 control procedures. There were no technical problems. All 6‐month and 1‐year graft and patient survival rates were 100 per cent in the DHOPE group. Six‐month graft survival and 1‐year graft and patient survival rates in the control group were 80, 67 and 85 per cent respectively. During DHOPE, median (i.q.r.) hepatic adenosine 5′‐triphosphate (ATP) content increased 11‐fold, from 6 (3–10) to 66 (42–87) µmol per g protein (P = 0·005). All DHOPE‐preserved livers showed excellent early function. At 1 week after transplantation peak serum alanine aminotransferase (ALT) and bilirubin levels were twofold lower in the DHOPE group than in the control group (ALT: median 966 versus 1858 units/l respectively, P = 0·006; bilirubin: median 1·0 (i.q.r. 0·7–1·4) versus 2·6 (0·9–5·1) mg/dl, P = 0·044). None of the ten DHOPE‐preserved livers required retransplantation for non‐anastomotic biliary stricture, compared with five of 20 in the control group (P = 0·140).

Conclusion

This clinical study of end‐ischaemic DHOPE in DCD liver transplantation suggests that the technique restores hepatic ATP, reduces reperfusion injury, and is safe and feasible. RCTs with larger numbers of patients are warranted to assess the efficacy in reducing post‐transplant biliary complications.

Increases donor pool

Decreased tacrolimus plasma concentrations during HCV therapy: a drug-drug interaction or is there an alternative explanation?

Chronic hepatitis C virus (HCV) infection can cause severe liver cirrhosis, for which liver transplantation is the only therapy. To prevent organ rejection, transplanted patients are treated with immunosuppressive agents. We describe two transplanted patients treated with tacrolimus who were simultaneously treated with direct-acting antivirals (DAAs) for their chronic HCV infection. No pharmacokinetic drug-drug interactions (DDIs) were expected between tacrolimus and the selected DAAs. However, in both patients, tacrolimus plasma concentrations decreased during HCV treatment. We hypothesise that decreased plasma concentrations were not caused by a DDI but were an indirect result of the clearance of the HCV infection. During chronic HCV infection, pro-inflammatory cytokines may inhibit cytochrome P450 (CYP) enzymes, which are primarily responsible for tacrolimus metabolism. If this is true, then with clearance of the virus the activity of these enzymes will normalise and tacrolimus metabolism will increase. These changes were clinically relevant because the tacrolimus dosage needed to be adjusted. Therefore, physicians should be aware that CYP substrates with narrow therapeutic ranges might require dose adaption during HCV therapy with DAAs.

The role of mycophenolate mofetil in the management of autoimmune hepatitis and overlap syndromes

BACKGROUND

Treatment failure occurs in 20% of autoimmune hepatitis patients on prednisolone and azathioprine (AZA). There is no established second line treatment.

AIM

To assess the efficacy of mycophenolate mofetil as second line treatment after AZA-intolerance or AZA-nonresponse in autoimmune hepatitis and overlap syndromes.

METHODS

Consecutive patients from the Dutch Autoimmune Hepatitis Group cohort, consisting of 661 patients, with autoimmune hepatitis or overlap syndromes, AZA-intolerance or AZA-nonresponse and past or present use of mycophenolate mofetil were included. Primary endpoint of mycophenolate mofetil treatment was biochemical remission. Secondary endpoints were biochemical response (without remission), treatment failure and prevention of disease progression.

RESULTS

Forty-five patients treated with mycophenolate mofetil were included. In autoimmune hepatitis remission or response was achieved in 13% and 27% in the AZA-nonresponse group compared to 67% and 0% in the AZA-intolerance group (P = 0.008). In overlap-syndromes remission or response was reached in 57% and 14% in the AZA-nonresponse group and 63% and 25% of the AZA-intolerance group (N.S.); 33% had side effects and 13% discontinued mycophenolate mofetil. Overall 38% had treatment failure; this was 60% in the autoimmune hepatitis AZA-nonresponse group. Decompensated liver cirrhosis, liver transplantations and death were only seen in the autoimmune hepatitis AZA-nonresponse group (P < 0.001).

CONCLUSIONS

Mycophenolate mofetil induced response or remission in a majority of patients with autoimmune hepatitis and azathioprine-intolerance and with overlap syndromes, irrespective of intolerance or nonresponse for azathioprine. In autoimmune hepatitis with azathioprine nonresponse mycophenolate mofetil is less often effective.

Similar liver transplantation survival with selected cardiac death donors and brain death donors

BACKGROUND

The outcome of orthotopic liver transplantation (OLT) with controlled graft donation after cardiac death (DCD) is usually inferior to that with graft donation after brain death (DBD). This study compared outcomes from OLT with DBD versus controlled DCD donors with predefined restrictive acceptance criteria.

METHODS

All adult recipients in the Netherlands in 2001-2006 with full-size OLT from DCD (n = 55) and DBD (n = 471) donors were included. Kaplan-Meier, log rank and Cox regression analyses were used.

RESULTS

One- and 3-year patient survival rates were similar for DCD (85 and 80 per cent) and DBD (86.3 and 80.8 per cent) transplants (P = 0.763), as were graft survival rates (74 and 68 per cent versus 80.4 and 74.5 per cent; P = 0.212). The 3-year cumulative percentage of surviving grafts developing non-anastomotic biliary strictures was 31 per cent after DCD and 9.7 per cent after DBD transplantation (P < 0.001). The retransplantation rate was similar overall (P = 0.081), but that for biliary stricture was higher in the DCD group (P < 0.001). Risk factors for 1-year graft loss after DBD OLT were transplant centre, recipient warm ischaemia time and donor with severe head trauma. After DCD OLT they were transplant centre, donor warm ischaemia time and cold ischaemia time. DCD graft was a risk factor for non-anastomotic biliary stricture.

CONCLUSION

OLT using controlled DCD grafts and restrictive criteria can result in patient and graft survival rates similar to those of DBD OLT, despite a higher risk of biliary stricture.

Liver transplantation: an update

Liver transplantation has been an accepted treatment for end-stage liver disease since the 1980s. Currently it is a highly successful treatment for this indication. The aim of this review is to give a general update on recent developments in the field of liver transplantation. In the last decades considerable progress has been made in the care of liver transplant candidates and recipients. At present the one- and five-year patient survival rates are approximately 85 and 75%. The indications for liver transplantation are shifting and the number of absolute contraindications is decreasing. In the coming years, an increase in the number of transplant candidates can be expected. An important problem is the shortage of donor organs, for which many solutions are being explored. A recently introduced method for recipient selection is the MELD score using simple laboratory measurements. Perioperative care at the present time is characterised by a high degree of standardisation and rapidly declining blood loss during transplantation. Long-term care includes awareness and management of recurrent disease. Important causes of morbidity and mortality such as de novo malignancies and cardiovascular disease should be adequately screened for and managed. With the increasing success of liver transplantation, physicians should aim at reaching a normal life expectancy and quality of life for transplant recipients.

Current health status of patients who have survived for more than 15 years after liver transplantation

BACKGROUND

Liver transplantation was started in our centre as early as 1979. We have studied the clinical outcome of patients surviving longer than 15 years, with special interest for the broad range of comorbidity and the self-perceived quality of life.

METHODS

All patients who underwent a liver transplantation at an adult age, between March 1979 and February 1991, and who had survived at least 15 years were eligible for the study. Data were collected from the medical records. Health-related quality of life was assessed using the Six-Dimensional EuroQol test.

RESULTS

The five-year survival of patients alive 15 years after transplantation was 78%. Thirty-seven patients are currently alive with a median follow-up of 18.8 years (range 15.0 to 26.8) after transplantation. Comorbidity consists predominantly of overweight (57%), osteoporosis (49%), de novo cancer (38%, mainly skin cancer), hypertension (38%), cardiovascular events (19%), diabetes mellitus (22%), cataract (24%), and renal clearance<50 ml/min (11%). The pattern of comorbidity seems to relate to the type of immunosuppression which consisted mainly of prednisolone and azathioprine. Quality of life was perceived as satisfactory (7 on a scale of 0 to 10). However, about half of the patients reported limitations in the domains mobility, usual activities and pain/discomfort. In addition a minority reported some anxiety or depression.

CONCLUSION

The outcome of liver transplantation in this early cohort of patients is fairly good. Improvements may be achieved by adaptations in the immunosuppressive regimen.

"Owl's eye" cells in a cervical smear of a transplant recipient: don't forget to inform the referring physician

Cytomegalovirus (CMV) infected cells in cervical smears are a rare finding but may have severe consequences. We describe the presence of characteristic "owl eye" cells in a conventional cervical smear. Medical history revealed a liver transplantation from a CMV seropositive donor 1 yr earlier. The patient experienced a delayed primary CMV infection 6 mo after transplantation. The current CMV infection was considered to be either a persisting manifestation of that primary infection or a reactivation. Since the patient experienced no clinical symptoms, it was decided to "wait and see". Infections with cytomegalovirus in immunocompromised patients may present with aspecific symptoms, but may lead to severe organ-threatening disease such as acute or chronic transplantation loss in transplant recipients. Although in the present case no serious consequences occurred, we stress that it is important to recognize these cells and report this finding promptly to the referring physician to prevent possible severe morbidity.

Increased incidence of azathioprine-induced pancreatitis in Crohn's disease compared with other diseases

BACKGROUND

Azathioprine is widely used in Crohn's disease. A major drawback is the occurrence of side-effects, especially acute pancreatitis. Acute pancreatitis is rarely seen when azathioprine is used for other diseases than Crohn's disease.

AIM

To survey side-effects of azathioprine after liver or renal transplantation, for systemic lupus erythematosis, Wegener's granulomatosis, autoimmune hepatitis, rheumatoid arthritis, ulcerative colitis or Crohn's disease.

METHODS

A computerized search using the term 'azathioprine' or 'imuran' was performed on the Hospital Information System of the university hospital Groningen, resulting in 1564 patients matching our criteria.

RESULTS

Eleven of 224 patients with Crohn's disease experienced acute pancreatitis (4.9%) compared with two of 129 (1.5%) with autoimmune hepatitis, two of 388 (0.5%) after renal transplantation, one of 254 (0.4%) after liver transplantation. Acute pancreatitis was more prevalent in Crohn's disease compared with any other disease. Azathioprine-toxicity necessitating withdrawal occurred significantly (P < 0,05) more in rheumatoid arthritis (78 of 317), ulcerative colitis (20 of 94) and Crohn's disease (52 of 224) compared with systemic lupus erythematosis (five of 73), Wegener's granulomatosis (six of 85), autoimmune hepatitis (eight of 129), after liver transplantation (17 of 254) and after renal transplantation (22 of 388).

CONCLUSIONS

Acute pancreatitis is strongly associated with Crohn's disease and rarely occurs with other underlying conditions. Overall azathioprine-induced toxicity and the necessity of withdrawal is more common in inflammatory bowel disease and rheumatoid arthritis compared with other diseases.

A moderate elevation of blood glucose level increases the effectiveness of thermoradiotherapy in a rat tumor model. I. Relative contributions of glucose and heating to tumor acidification

PURPOSE

To establish dose-effect relationships for tumor acidification induced by heat and glucose as a basis for testing the value of adding glucose administration to combined heat and x-ray treatment at clinically achievable glucose and temperature levels.

METHODS AND MATERIALS

Rhabdomyosarcoma BA1112 was grown s.c. in the upper leg of 16-20-week-old Wag/Rij rats. Animals were given 2 consecutive 100-min periods of saline (S) or glucose (G) infusion, while keeping tumor temperature at 37 degrees, 42 degrees, or 43 degrees C for 1 or 2 periods, in various combinations, each involving 6 animals. Glucose was infused i.v. as a 20% solution at 2.4-3 g/kg/h. Tumors were heated using 2,450-MHz electromagnetic radiation, and tumor pH was measured using a 0.7 mm fiberoptic probe.

RESULTS

Mean overall baseline pH was 7.00 (SD 0.10). The change induced by G37G43 (i.e., glucose infusion for a full 200 min, first 100 min at 37 degrees C, final 100 min at 43 degrees C) was -0.48 +/- 0.03 (SEM) pH units, and -0.17 +/- 0.03 for S37S43. The effect of G37G42 was -0.37 +/- 0.03 pH units, compared with -0.08 +/- 0.02 for S37S42 and -0.28 +/- 0.04 for glucose alone (G37G37). Glucose was less effective when given after or fully parallel to heating: -0.21 +/- 0.02 pH units for S43G37 and -0.37 +/- 0.02 for G43G43.

CONCLUSION

The glucose-induced tumor pH drop is much more pronounced than that induced by heat, both of which are dose dependent. The effects of glucose and heat seem additive if heating is started when glucose-induced acidification has reached its plateau level, but the overall effect is diminished if administration is fully simultaneous or in reversed order. Schedule G37G43 is optimal with respect to tumor acidification. Its predicted superiority in thermoradiotherapy as compared with S37S42, S37S43, and G37G42 treatment regimens was confirmed in a subsequent experimental tumor control study.

A moderate elevation of blood glucose level increases the effectiveness of thermoradiotherapy in a rat tumor model II. Improved tumor control at clinically achievable temperatures

PURPOSE

To assess the therapeutic gain (at the TCD(50) level) that can be obtained by boosting thermoradiotherapy with intravenous glucose infusion at different temperatures. This completes our series of studies to determine the optimal conditions and the effectiveness of glucose administration at clinically achievable glucose levels and treatment temperatures.

METHODS AND MATERIALS

Subcutaneous rat rhabdomyosarcoma BA1112 was irradiated with graded single doses of 300-kV X-rays (dose range 0-60 Gy). Fifteen minutes after irradiation, a 100-min intravenous infusion was started, consisting of either glucose (20% solution, 2.4-3 g/kg/h) or saline as a control. Then heat was applied to the tumors at 42 degrees C or 43 degrees C (water bath) during a subsequent 100-min period of infusion. Tumor control was scored as the absence of palpable growth at 100 days after treatment.

RESULTS

Glucose infusion enhanced tumor control independent of temperature in the range 42-43 degrees C. At 42 degrees C, the TCD(50) for X-irradiation decreased by 5.9 Gy (SEM 1.8 Gy), from 41.6 (1.6) to 35.7 (1.5) Gy, and at 43 degrees C from 33.3 (1.6) to 27.3 (1.5) Gy, representing a glucose enhancement ratio of approximately 1.2. At doses corresponding to the TCD(50) at either 42 or 43 degrees C, the addition of glucose increased tumor control from 50% to 70%. An enhancement ratio of 2.1 was found for the combination of irradiation, glucose infusion, and heating at 43 degrees C, with respect to irradiation alone (TCD(50) 56.3 Gy, reanalyzed earlier data). The contribution of combined heat and glucose to tumor control represented an additive effect, probably on the hypoxic cell population.

CONCLUSION

Moderate glucose administration (blood concentration 300 mg/100 mL) sizably improves experimental tumor control after combined X-irradiation and hyperthermia under clinically feasible conditions. Clinical treatment should benefit from this additional modality, in particular if unsatisfactory local control rates are due to insufficient heating. The therapeutic gain has to be evaluated further in clinical studies.

Equivalence of hyperfractionated and continuous brachytherapy in a rat tumor model and remarkable effectiveness when preceded by external irradiation

PURPOSE

In clinical brachytherapy, there is a tendency to replace continuous low-dose-rate (LDR) irradiation by either single-dose or fractionated high-dose-rate (HDR) irradiation. In this study, the equivalence of LDR treatments and fractionated HDR (2 fractions/day) or pulsed-dose-rate (PDR, 4 fractions/day) schedules in terms of tumor cure was investigated in an experimental tumor model.

METHODS AND MATERIALS

Tumors (rat rhabdomyosarcoma R1M) were grown s.c. in the flank of rats and implanted with 4 catheters guided by a template. All interstitial radiation treatment (IRT) schedules were given in the same geometry. HDR was given using an (192)Ir single-stepping source. To investigate small fraction sizes, part of the fractionated HDR and PDR schedules were applied after an external irradiation (ERT) top-up dose. The endpoint was the probability of tumor control at 150 days after treatment. Cell survival was estimated by excision assay.

RESULTS

Although there was no fractionation effect for fractionated HDR given in 1 or 2 fractions per day, TCD(50)-values were substantially lower than that for LDR. A PDR schedule with an interfraction interval of 3 h (4 fractions/day), however, was equivalent to LDR. The combination of ERT and IRT resulted in a remarkably increased tumor control probability in all top-up regimens, but no difference was found between 2 or 4 fractions/day. Catheter implantation alone decreased the TCD(50) for single-dose ERT already by 17.4 Gy. Cell viability assessed at 24 h after treatment demonstrated an increased effectiveness of interstitial treatment, but, after 10 Gy ERT followed by 10 Gy IRT (24-h interval), it was not less than that calculated for the combined effect of these treatments given separately.

CONCLUSION

In full fractionation schedules employing large fractions and long intervals, the sparing effect of sublethal damage repair may be significantly counteracted by reoxygenation. During 3-h intervals, however, repair may be largely completed with only partial reoxygenation causing PDR schedules to be less effective than fractionated HDR, and equivalent to LDR. Brachytherapy with clinically sized fractions after a large external top-up dose showed a remarkable increase in tumor control rate with no effect of fractionation (up to 4 fractions/day), which could not be fully explained by differences in dose distribution or in the cell viability assessed after treatment. This suggests a longer lasting effect on cell survival or radiosensitivity associated with catheter implantation shortly after the top-up dose.

Rapid decreases in donor-specific cytotoxic T lymphocyte precursor frequencies and graft outcome after liver and lung transplantation

BACKGROUND

A decrease in donor-specific T cell precursor frequencies as seen late, one or more years, after transplantation is assumed to reflect transplantation tolerance, a condition important for long term acceptance of the allograft. However, such late decreases also occur in recipients that developed chronic transplant dysfunction questioning its relevance in transplantation tolerance. We investigated whether early, i.e., the first 6 months, decreases in donor-specific T cell precursor frequencies reflect transplantation tolerance and predict graft outcome after liver and lung transplantation.

METHODS

Donor and third party specific cytotoxic (CTLp) and helper T lymphocyte precursor (HTLp) frequencies were analyzed in pretransplant and 1 (or 2) and 6-month blood samples taken from liver and lung recipients and were correlated with graft outcome.

RESULTS

In liver allograft recipients with good graft function (n=7), mean donor-specific CTLp frequencies decreased as early as 1 month after transplantation and remained low thereafter. In contrast, mean CTLp frequencies did not decrease in liver allograft recipients with chronic transplant dysfunction (n=6). In lung allograft recipients, donor-specific CTLp frequencies remained relatively high and frequencies were not different between recipients without (n=6) or with (n=6) chronic transplant dysfunction. Donor-specific HTLp frequencies did not change significantly after liver or lung transplantation and did not differ between recipients without or with chronic transplant dysfunction.

CONCLUSIONS

An early decrease in donor-specific CTLp correlates with good graft outcome after liver transplantation. Such rapid decreases in alloreactivity do not occur after lung transplantation illustrating the unique capacity of liver allografts to induce transplantation tolerance.

Increased cancer risk after liver transplantation: a population-based study

BACKGROUND/AIMS

Development of de novo malignancies emerges as a serious long term complication after liver transplantation.

METHODS

We reviewed the medical records of 174 adult one-year survivors for de novo malignancies. The observed cancer rates were compared with the expected cancer rates in the Dutch population.

RESULTS

Twenty-one of the 174 patients developed 23 malignancies (12%). Skin and lip cancer accounted for 12 of the 23 malignancies (52%). Only one patient had a B-cell lymphoma. The cumulative risk for de novo malignancy was 6, 20, and 55% at 5, 10, and 15 years after transplantation, respectively. The overall relative risk (RR) as compared with the general population was 4.3 (95% confidence interval 2.4-7.1). Significantly increased RRs were observed for non-melanoma skin cancer (RR 70.0), non-skin solid cancer (RR 2.7), renal cell cancer (RR 30.0), and colon cancer (RR 12.5). Multivariate analysis showed that an age > 40 years and pretransplant use of immunosuppression were significant risk factors.

CONCLUSIONS

An increased risk of cancer exists after liver transplantation, for both for skin/lip cancer, and other solid tumors. Older age and the use of immunosuppression are risk factors.

Tumor hypoxia--a confounding or exploitable factor in interstitial brachytherapy? Effects of tissue trauma in an experimental rat tumor model

PURPOSE

To evaluate the potential effects of tumor hypoxia induced by afterloading catheter implantation on the effectiveness of brachytherapy in a rat tumor model.

METHODS AND MATERIALS

Afterloading catheters (4) were implanted in subcutaneously growing R1M rhabdomyosarcoma in female Wag/Rij rats. A MicroSelectron (Nucletron) was used for interstitial high-dose-rate irradiation ((192)Ir). Tumor oxygenation, perfusion, and cell survival were assessed by pO(2) histography (Eppendorf), Tc-99m injection, and excision assay, respectively.

RESULTS

Tumor perfusion was markedly reduced at 1 h after catheter implantation (33.9 +/- 6.0% (SEM, n = 9) of control) and partly recovered after 5 h (61.5 +/- 12.2%). At 24 h, the perfusion level reached control values (100.6 +/- 25.7%), but was highly variable with some of the tumors showing hardly any recovery at all. Tumor oxygenation showed a similar pattern, but with less recovery. Median pO(2) readings were 13.5, 1.2, and 5.3 mm Hg before and at 1 and 24 h after implantation, respectively (7 tumors). The percentages of pO(2) readings </= 2.5 mm Hg were 18.9%, 55.6%, and 41.3% at these time points. The difference in cell survival after irradiation (10 Gy) at 1 or 24 h after implantation was compatible with a radiobiological oxygen effect.

CONCLUSION

Implantation of brachytherapy afterloading catheters induces an increased level of hypoxia for several hours by disrupting tumor perfusion, causing both a modest degree of direct cell kill and a significant reduction of the radiation effect. This transient hypoxia might be exploited by combining irradiation with properly timed treatments targeting hypoxic cells.

Single dose irradiation response of pig skin: a comparison of brachytherapy using a single, high dose rate iridium-192 stepping source with 200 kV X-rays

An experimental brachytherapy model has been developed to study acute and late normal tissue reactions as a tool to examine the effects of clinically relevant multifractionation schedules. Pig skin was used as a model since its morphology, structure, cell kinetics and radiation-induced responses are similar to human skin. Brachytherapy was performed using a microSelectron high dose rate (HDR) afterloading machine with a single stepping source and a custom-made template. In this study the acute epidermal reactions of erythema and moist desquamation and the late dermal reactions of dusky mauve erythema and necrosis were evaluated after single doses of irradiation over a follow-up period of 16 weeks. The major aims of this work were: (a) to compare the effects of iridium-192 (192Ir) irradiation with effects after X-irradiation; (b) to compare the skin reactions in Yorkshire and Large White pigs; and (c) to standardize the methodology. For 192Ir irradiation with 100% isodose at the skin surface, the 95% isodose was estimated at the basal membrane, while the 80% isodose covered the dermal fat layers. After HDR 192Ir irradiation of Yorkshire pig skin the ED50 values (95% isodose) for moderate/severe erythema and moist desquamation were 24.8 Gy and 31.9 Gy, respectively. The associated mean latent period (+/- SD) was 39 +/- 7 days for both skin reactions. Late skin responses of dusky mauve erythema and dermal necrosis were characterized by ED50 values (80% isodose) of 16.3 Gy and 19.5 Gy, with latent periods of 58 +/- 7 days and 76 +/- 12 days, respectively. After X-irradiation, the incidence of the various skin reactions and their latent periods were similar. Acute and late reactions were well separated in time. The occurrence of skin reactions and the incidence of effects were comparable in Yorkshire and Large White pigs for both X-irradiation and HDR 192Ir brachytherapy. This pig skin model is feasible for future studies on clinically relevant multifractionation schedules in a brachytherapy setting.

Clinical significance of anti-neutrophil cytoplasmic antibodies (ANCA) in autoimmune liver diseases

BACKGROUND/AIMS

The clinical relevance of anti-neutrophil cytoplasmic antibodies (ANCA) in autoimmune liver disease is unclear. Defining the antigenic specificities of ANCA in these diseases may improve their clinical significance.

METHODS

We studied the target antigens of ANCA in 88 patients with autoimmune hepatitis, 53 patients with primary biliary cirrhosis, and 55 patients with primary sclerosing cholangitis by indirect immunofluorescence, antigen-specific enzyme-linked immunosorbent assays, and immunodetection on Western blot, using an extract of whole neutrophils as a substrate. We related the data to clinical symptoms of autoimmune liver disease.

RESULTS

By indirect immunofluorescence, ANCA were present in 74% of patients with autoimmune hepatitis, 26% of patients with primary biliary cirrhosis, and 60% of patients with primary sclerosing cholangitis. Major antigens were catalase, alpha-enolase, and lactoferrin. The presence of ANCA as detected by indirect immunofluorescence was associated with the occurrence of relapses in autoimmune hepatitis, with decreased liver synthesis function in primary biliary cirrhosis and in primary sclerosing cholangitis, and with increased cholestasis in primary sclerosing cholangitis. ANCA of defined specificities had only limited clinical relevance.

CONCLUSIONS

ANCA as detected by indirect immunofluorescence seem associated with a more severe course of autoimmune liver disease. The target antigens for ANCA in these diseases include catalase, alpha-enolase, and lactoferrin. Assessment of the antigenic specificities of ANCA in autoimmune liver disease does not significantly contribute to their clinical significance.

Bone mineral density in the long term after liver transplantation

Hepatic osteodystrophy is a complication of chronic liver disease and bone mass is known to decline further in the first year after liver transplantation. The present study focused on bone mineral density (BMD) between 1 and 15 years after liver transplantation under a prednisolone- and azathioprine-based immunosuppressive regimen. Three groups of adult patients were studied: group 1, 45 patients with a follow-up of 5-9 years after transplantation, had BMD measurements done at 1, 2 and 5 years after transplantation; group 2, 17 patients with a follow-up of 10-14 years, had BMD measurements done at 5 and 10 years; group 3, 4 patients with a follow-up of more than 15 years, had BMD measurements done at 10 and 15 years. BMD of lumbar spine (L1-L4) and proximal femur was measured using dual-energy X-ray absorptiometry, and at the same time radiographs of the spine and hips were made. Spinal BMD increased significantly, during the second post-transplant year; subsequently no significant changes were seen. Proximal femur BMD decreased slightly, but significantly during the second year, and remained stable afterwards. About one-third of patients had a BMD below the fracture threshold (= 0.798 g/cm2 for the lumbar spine and 0.675 g/cm2 for the hip) during the follow-up. In 5 of the 66 patients studied, new vertebral fractures occurred. No fractures or avascular necrosis of the hips were seen. Furthermore, after transplantation lower Z-scores of the hip were found in patients with pre-transplant cholestatic liver diseases, and lower Z-scores of the lumbar spine were found in men compared with women. Long-term follow-up of BMD up to 15 years after transplantation revealed an improvement mainly in the second postoperative year with no deterioration afterwards. Nevertheless a substantial number of patients (around one-third) kept a BMD below the fracture threshold, and new fractures may occasionally occur. The overall outcome appeared somewhat less favorable in men and patients transplanted for cholestatic liver diseases.

Low HLA-DR expression on peripheral blood monocytes predicts bacterial sepsis after liver transplantation: relation with prednisolone intake

Bacterial sepsis remains a frequent complication after liver transplantation. We previously reported the results of a pilot study that suggested that low expression of HLA-DR on monocytes is a predictive marker for the occurrence of sepsis. We have studied the value of this marker in an additional cohort of patients, and have analyzed the relation of HLA-DR expression with the use of immunosuppressive agents. 20 adult liver transplantation patients were prospectively monitored during the first 4 weeks after transplantation. All were treated according to standard protocols. The percentage of monocytes expressing HLA-DR was measured by flow cytometry. In addition, the effects of incubation of monocytes with prednisolone in vitro on the expression of HLA-DR was determined in 7 healthy volunteers. Seven patients developed bacterial sepsis after a median 15 (range 10-20) days after transplantation. HLA-DR expression was significantly lower in these patients on days 7, 14, 21, and 28 after transplantation compared with non-septic patients. The percentage of HLA-DR positive monocytes was 30% or less, 3 (1-8) days before onset of sepsis. On day 7 after transplantation, HLA-DR expression on 50% or less of monocytes had a positive predictive value for sepsis of 71%, whereas the negative predictive value was 85%. Patients who developed sepsis received significantly more prednisolone. Incubation with prednisolone in vitro lowered the expression of HLA-DR in a dose-dependent manner. We conclude that low HLA-DR expression on monocytes is a marker for a high risk of subsequent sepsis in liver transplantation patients. This high risk may be (at least partly) related to the dose of prednisolone.

The central role of monocytes in the pathogenesis of sepsis: consequences for immunomonitoring and treatment

Despite important advances in critical care medicine during the last two decades, the mortality rate of sepsis has remained high, probably because the pathogenesis of sepsis is still incompletely understood. Recent studies have shown that sepsis is a bimodal entity. The first phase is characterized by the systemic release of pro-inflammatory cytokines such as tumor necrosis factor-alpha (TNF-alpha), interleukin-1 (IL-1), and IL-8, and by activation of the complement and coagulation cascades. In the second phase, anti-inflammatory mediators such as transforming growth factor-beta (TGF-beta), IL-10 and prostaglandin E2 (PGE2) may be released in an effort to counteract ongoing inflammation. Depending whether the pro- or anti-inflammatory response predominates, sepsis results in a systemic inflammatory response syndrome (SIRS), or a compensatory anti-inflammatory response syndrome (CARS). So far, most efforts to intervene in the immunopathogenesis of sepsis have been directed at the pro-inflammatory response. None of these interventions has been shown to improve the prognosis of sepsis, possibly because many patients were already in a state in which anti-inflammatory responses dominated. Recently, it has been shown that decreased expression of HLA-DR on monocytes in patients with sepsis constitutes a marker for CARS. We suggest that HLA-DR expression on monocytes might constitute a useful indicator of the immunological status of the individual patient with sepsis and a guide for treatment. Patients with CARS, as manifested by low HLA-DR expression, might benefit from immunostimulants, while patients with SIRS and normal or high monocyte HLA-DR expression should receive treatment directed to interfere with pro-inflammatory pathways.

Donor-specific hyporeactivity after liver transplantation: prominent decreases in donor-specific cytotoxic T lymphocyte precursor frequencies independent of changes in helper T lymphocyte precursor frequencies or suppressor cell activity

BACKGROUND

The development of immunological donor-specific hyporeactivity may account for the low incidence of chronic rejection after clinical liver transplantation. We investigated whether hyporeactivity commonly develops after liver transplantation by analyzing precursor frequencies of donor-reactive cytotoxic (CTLp) and helper (HTLp) T lymphocytes and mixed lymphocyte culture (MLC) reactivity in liver allograft recipients. We further studied whether CTLp hyporeactivity correlated with changes in donor-specific HTLp frequencies or suppressor cell activity.

METHODS

CTLp and HTLp frequencies and MLC reactivity against donor and third-party spleen cells were determined in pre- and posttransplantation peripheral blood samples from 18 recipients with good graft function 2 years after transplantation. By mixing posttransplantation samples (with "putative" suppressor cell activity) with pretransplantation samples (in which normal CTL activity with no suppressor cell activity is expected), the presence of suppressor cell activity in peripheral blood was analyzed.

RESULTS

Two years after transplantation, all but one (94%) of the recipients had developed CTLp hyporeactivity as evidenced by reduced donor-specific CTLp frequencies. The development of hyporeactivity was not specific for any particular underlying disease. The occurrence of HTL hyporeactivity, however, was less frequent: 38% and 20% of recipients were HTLp and MLC hyporeactive, respectively. Decreases in CTLp frequencies did not correlate with decreased donor-specific HTL function or suppressor cell activity in peripheral blood samples.

CONCLUSIONS

Donor-specific CTLp hyporeactivity can develop in the majority of liver allograft recipients, irrespective of underlying disease. Donor-specific HTL hyporeactivity, however, occurs infrequently. A reduction in donor-specific CTLp frequencies was found to be independent of changes in donor-specific HTLp or suppressor cell activity, suggesting that other mechanisms (e.g., clonal deletion) are operative in the reduction of donor-specific CTLp after liver transplantation.

Routine Doppler ultrasound for the detection of clinically unsuspected vascular complications in the early postoperative phase after orthotopic liver transplantation

To assess the role of routine Doppler ultrasound in the detection of clinically unsuspected vascular complications in the early postoperative phase after orthotopic liver transplantation (OLT), the findings of 858 routinely performed Doppler ultrasound examinations were analyzed in 268 transplants. At various time intervals after OLT, we encountered 46 abnormal Doppler findings: hepatic artery (thrombosis), portal vein [anastomotic stenosis, (non)occlusive thrombosis or reversed flow], inferior vena cava [anastomotic stenosis with reversed flow, no flow, or (non)occlusive thrombosis], and hepatic veins (to-and-fro flow or stenosis with reversed flow) in 14, 20, 9, and 2 transplants, respectively. Most of these abnormal Doppler findings were confirmed by angiography, cavography, or surgery. The positive predictive value for hepatic artery thrombosis (HAT) was 12 out of 14, or 86%. In the first 2 weeks after OLT, routine Doppler ultrasound revealed 20 of the 46 abnormal findings (43%). Clinically unsuspected complications of the hepatic artery, portal vein, inferior vena cava, and hepatic veins were found in 9 of the 14 (64%), 6 of the 20 (30%), 3 of the 9 (33%), and 2 of the 2 (100%) transplants, respectively. The highest incidence--nine vascular complications--was found on the 1st day. On each of the remaining days (except for the 2nd and 9th days), one or two vascular complications were detected. HAT was found mainly in the 1st week. Vascular complications developed independently or concomitantly. We conclude that routine Doppler ultrasound is very important for the detection of clinically unsuspected vascular complications, particularly HAT, in the first 2 weeks after OLT. We recommend routine Doppler ultrasound of all hepatic vessels every 3 days in the early postoperative phase after OLT. Special attention should be paid to the 1st day.

Donor-specific immunological non-responsiveness after liver transplantation

Since the rate of immunological losses of liver allograft after the immediate posttransplant period is much lower than in other organs, we studied the immune responses against donor HLA antigens in 18 patients with a good long-term outcome to determine whether the development of a state of immunological non-responsiveness to donor antigens might account for this favorable outcome. The reactivity against donor spleen cells was measured before and 2 years after transplantation. The reactivity in mixed lymphocyte culture (MLC) and the frequencies of cytotoxic T cell precursors (CTLp) were determined. Responses against third-party spleen cells were determined concurrently to exclude a generalized reduction of immunocompetence due to chronic immunosuppressive treatment. Before orthotopic liver transplantation, the majority of patients had normal T cell responses against donor antigens that were comparable to those against third-party antigens. Two years after transplantation, donor-specific MLC non-reactivity had developed in 10 of the 18 (56%) patients. In addition, 15 of 18 (83%) patients had developed donor-specific cytotoxic T cell (CTL) non-responsiveness; 2 had reduced numbers of CTLp against both donor and third-party cells, while the remaining patient had maintained reactivity against donor antigens. In conclusion, donor-specific non-responsiveness is present in the majority of patients 2 years after successful liver transplantation, but occurs predominantly at the CTL level.

Quantification of immunosuppression by flow cytometric measurement of intracellular cytokine synthesis

The availability of a method to measure the effects of drugs on immune reactivity should be helpful in optimizing treatment after organ transplantation. Since cyclosporine A (CSA) interferes with activation of T cells and cytokine synthesis, production of IL-2 and IFN-gamma might constitute a marker of this drug's effects. We measured the capacity for mitogen-stimulated production of these cytokines in whole blood by using immunostaining of intracellular and membrane antigens, followed by flow cytometry. The percentage of CD4+ T cells producing IL-2 or IFN-gamma was strongly reduced in 20 transplant patients compared with 24 healthy controls. The capacity for IL-2 production of CD4+ and CD8+ cells correlated inversely with CSA blood levels (P values 0.0087 and 0.0396, respectively). IFN-gamma production by CD4+ T cells showed a negative correlation with the prednisolone dose (P = 0.0175) and, for the CD8+ subset, with CSA trough levels (P = 0.0023). These data show that inhibition of T cell cytokine synthesis by CSA and prednisolone can be quantified.

Expression of p53, p21/WAF/CIP, Bcl-2, Bax, Bcl-x, and Bak in radiation-induced apoptosis in testicular germ cell tumor lines

PURPOSE

Testicular germ cell tumors (TGCTs) represent one of the few tumor types that are curable by antineoplastic therapy, probably due to the high sensitivity of this neoplasm to induction of apoptosis by chemotherapeutic agents and/or ionizing radiation. Here, we tested cell susceptibility to radiation-induced apoptosis in a panel of TGCT cell lines and attempted to correlate this with the known potentially relevant molecular determinants (p53 gene status and Bcl-2 family proteins) of apoptosis.

METHODS AND MATERIALS

Induction of apoptosis by gamma-radiation was morphologically recognized in NT2, NCCIT, S2, and 2102 EP using Hoechst/PI staining and additionally confirmed by Western blot analysis of PARP cleavage. The p53 gene status was estimated by sequence analysis. Expression of p21/WAF/CIP was determined by Northern blot analysis and immunoblotting was used to monitor p53, Bax, Bcl-2, Bcl-x, and Bak protein levels. In vitro colony formation was studied to establish clonogenic survival curves.

RESULTS

NT2 and NCCIT appeared to be susceptible for radiation-induced apoptosis, contrasting 2102 EP and S2 which were highly resistant. Sequence analysis showed that NT2, S2, and 2102 EP are homozygous for wild-type p53 (wtp53), whereas NCCIT contains mutant p53 (mtp53). NT2 and 2102 EP cells showed radiation-induced p53 upregulation, while NCCIT (mtp53) and S2 (no p53 protein) cells did not. Consistently, gamma-radiation-induced DNA damage resulted in a p53-dependent transactivation of the p21/WAF/CIP gene in NT2 and 2102 EP, but not in mtp53-containing NCCIT cells and p53 nonexpressing S2 cells. Constitutive expression of Bax, Bcl-2, Bcl-x, and Bak was not affected by radiation and showed no correlation with cell susceptibility to radiation-induced apoptosis. A discrepancy was found between apoptosis and reproductive death.

CONCLUSIONS

The present study revealed that: i) the presence of wtp53 may not be absolutely required for the hypersensitivity for radiation-induced apoptosis in TGCT cell lines, ii) the molecular mechanism underlying the unique radiosensitivity was independent of the expression of Bcl-2 family proteins, and iii) cell susceptibility to apoptosis induction is not sufficiently informative to predict intrinsic radiosensitivity as determined by clonogenic survival.

Quantitation of immunosuppression by flow cytometric measurement of the capacity of T cells for interleukin-2 production

BACKGROUND

Methods to quantitate the effects of immunosuppressive drugs on immune reactivity might be helpful for monitoring immunosuppressive treatment. Cyclosporine (CsA) inhibits the induction of cytokine synthesis in T cells, and measurement of interleukin (IL)-2 production might constitute a parameter of this drug's effect.

METHODS

We determined the percentages of CD4+ and CD8+ lymphocytes producing IL-2 upon stimulation by phorbol myristate acetate and calcium ionophore in whole blood culture, using immunostaining of intracytoplasmatic and membrane markers, followed by multiparameter flow cytometry. A total of 38 clinically stable transplant patients on various immunosuppressive protocols were studied.

RESULTS

The percentage of CD4+ T cells producing IL-2 was strongly reduced in patients compared with healthy controls (23% [range, 3-68%] vs. 59.0% [range, 41-70%]; P=0.000035). The percentage of CD4+ T cells producing IL-2 was negatively correlated with the CsA level (Rc=-0.0821, P=0.00002297) but not with prednisolone or azathioprine doses. Fewer CD8+ T cells produced IL-2 in transplant patients compared with controls, but the difference failed to reach statistical significance. The percentage of CD8+ T cells capable of producing IL-2 was inversely correlated to CsA levels (Rc=-0.0375, P=0.0011).

CONCLUSIONS

These data suggest that the functional effects of CsA in transplant recipients can be quantitatively determined and that the capacity of CD4+ T cells to produce IL-2 upon stimulation constitutes a functional parameter of CsA effects on the immune system. Prospective studies are required to determine whether this method is useful for clinical monitoring.

Autoimmune hepatitis: pathogenesis, diagnosis and treatment

BACKGROUND

Autoimmune hepatitis (AIH) is a chronic necro-inflammatory disease of the liver. Early recognition is important in order to prevent the development of cirrhosis. This review discusses recent developments in the fields of diagnosis, pathophysiology and management of AIH.

METHODS

Relevant manuscripts were identified using an electronic database, and by hand search of a personal library.

RESULTS AND CONCLUSIONS

Description of new auto-antibodies, and formulation of diagnostic criteria and a scoring system by an international panel constitute important advances that may help diagnosis of the disease at an early stage. While a satisfying animal model of the disease is lacking, clinical observations have led to the formulation of a pathophysiological model. Current treatment has a failure rate of about 13%, and is unable to induce a permanent remission in most patients. New immunosuppressive agents (cyclosporine, tacrolimus and mycophenolate mofetil) appear promising, and should be evaluated in controlled trials.

Low HLA-DR expression on monocytes as a prognostic marker for bacterial sepsis after liver transplantation

BACKGROUND

Low HLA-DR expression on monocytes is associated with an increased risk of infection after surgery or trauma. We determined the value of this parameter as a marker for sepsis after liver transplantation.

METHODS

The percentage of monocytes expressing HLA-DR was determined by flow cytometry before and after liver transplantation in nine patients. Five lung and 20 kidney transplant recipients served as controls.

RESULTS

Bacterial sepsis occurred in 5 of 9 liver transplant patients and 0 of 24 control patients. Monocyte HLA-DR expression decreased <50% in all five patients with sepsis. HLA-DR expression dropped before (n=4) or at the time of sepsis (n=1), and remained low for 13 weeks. HLA-DR expression remained >50% in the four liver transplant patients without sepsis. Only 1 of 25 control patients had persistently low monocyte HLA-DR expression.

CONCLUSIONS

Monitoring of monocyte HLA-DR expression may be helpful in identifying liver transplant patients who have an increased risk of imminent bacterial sepsis.

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.

Incidence, risk factors, and outcome of antithymocyte globulin treatment of steroid-resistant rejection after liver transplantation

We retrospectively analyzed the incidence and outcome of steroid-resistant rejection (SRR) during the first 6 months after OLT in 126 patients receiving triple immunosuppression. A total of 95 patients either did not experience acute rejection at all or had acute rejection that subsided without additional treatment. A total of 31 patients had biopsy-proven acute rejection that required therapy: 18 patients had acute rejection that responded to steroid therapy (steroid-sensitive rejection, SSR); the remaining 13 patients had SRR and received ATG. At the onset of acute rejection, no differences in clinical, biochemical, or immunological parameters were present between patients with SSR and SRR. However, the histological grade of acute rejection in the initial biopsy was higher in patients with SRR (P = 0.05). ATG treatment was effective in 10 of the 13 patients and was not associated with an increased incidence of opportunistic infections. Patient and graft survival rates at 2 years were comparable in the three groups. These data show that the incidence of SRR during the first 6 months after OLT is low, and that its treatment with ATG is both effective and well tolerated.

Evidence for an increased rate of bacterial infections in liver transplant patients with cytomegalovirus infection

It has been reported that cytomegalovirus (CMV) infections increase the susceptibility of transplant patients for other opportunistic infections. Most of these studies date back from a time when CMV infection was difficult to diagnose and antiviral treatment not available. We therefore analyzed CMV-related morbidity after OLT in 111 consecutive patients. CMV monitoring was done weekly using the antigenemia assay, a quantitative marker of the viral load, in addition to serology. CMV infection occurred in 66/95 (69%) evaluable patients. Antigenemia was detected in 94% of them. The number of CMV antigen-positive cells was helpful to monitor the course of infection and differentiate CMV disease from other complications. CMV infection was symptomatic in 48/66 (73%) patients. Mild disease occurred in 30 patients, and severe constitutional symptoms or organ involvement in 18. No patient died as a direct result of CMV infection, but mortality between day 30 and 180 tended to be higher in CMV-infected patients (15 vs. 0%, p < 0.1). CMV infection was associated with a 2.45-fold higher incidence of major infections between day 30 and 180 after OLT (p < 0.05). Most of these infections were caused by gram-positive cocci. We conclude that CMV not only causes substantial morbidity, but also increases the risk of bacterial infections.

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.

Temporary vascular occlusion and glucose: effects on tumour and normal tissue pH in animal experiments

The relationship between duration of a period of vascular occlusion and magnitude of pH decrease in tumour and normal tissue was investigated in rats. To acidify tissue pH further, moderate dose glucose (2.4-3.0 g.kg(-1).hr(-1)) was administered intravenously through a catheter positioned in a tail vein, immediately after the clamp was released. This sequence of pH modifying modalities was chosen since it is employed in clinical regional isolation perfusion for recurrence of malignant melanoma of the limbs. Tumour pH in rat rhabdomyosarcoma BA1112 decreased more than normal tissue pH under 10, 20, 30 or 60 min of temporary vascular occlusion. Administration of glucose following any period of clamping always decreased tumour pH further. The largest pH decrease (0.29 pH units) was obtained after 30 min of clamping followed by 60 min glucose and 60 min saline infusion. In the clinic the combination of a maximum of 30 min of clamping followed by moderate dose glucose infusion, which can decrease tumour pH effectively, can be easily achieved in the setting of regional isolation perfusion. It can be used for treatment modalities that are known to be enhanced at lowered tissue pH, such as hyperthermia and certain chemotherapeutic drugs. These results form the basis for studying the therapeutic gain which can be obtained with this model.

Thermal enhancement of both tumour necrosis factor alpha-induced systemic toxicity and tumour cure in rats

In vitro and in vivo studies have suggested synergistic anti-tumour activity of combined hyperthermia and tumour necrosis factor alpha (TNF-alpha). However, some studies indicated an increased systemic toxicity of TNF by additional hyperthermia. The aim of this study was to obtain starting dosages for a clinical phase I study on the application of deep local hyperthermia and systemic TNF. We investigated the effect of local hyperthermia on the toxicity and efficacy of systemic TNF. Rats (Wag/Rij) carrying a subcutaneously transplanted osteosarcoma in the hind leg received a single intravenous dose of recombinant human (rh) TNF-alpha, either at normothermia or at hyperthermia, by positioning the tumour bearing hind leg in a water bath of 43 degrees C. Dose-effect curves for lethality and tumour cure were established and LD50 and TCD50 values were calculated. Systemic toxicity was increased by local hyperthermia. The LD50 values (+/- s.e.) were 1088 (+/- 61) micrograms kg-1 at normothermia and 205 (+/- 23) micrograms kg-1 at hyperthermia, resulting in a thermal enhancement ratio (TER) of 5.3. Following normothermia, tumour cures were observed at TNF concentrations of 1000-1300 micrograms kg-1, while this was observed at doses of 50-300 micrograms kg-1 when combined with hyperthermia (TCD50 values of 1211 and 188 micrograms kg-1 respectively), resulting in a TER of 6.4. Systemic toxicity and anti-tumour activity of TNF are both increased by local hyperthermia. A safe starting dose for the combined clinical treatment would be 10% of the dose of TNF-alpha that has been recommended for phase II studies on intravenous bolus administration of TNF-alpha at normothermia. In view of the large variability in tumour sensitivity for TNF-alpha, the clinical usefulness of this combined treatment modality has to be determined.

CMV infection after organ transplantation: immunopathological and clinical aspects

Cytomegalovirus (CMV), a member of the Herpes virus family, is a seemingly harmless infectious agent for healthy individuals. However, it is one of the most important opportunistic pathogens in immunosuppressed patients, particularly in organ transplant recipients. Due to its monocytotropic character, CMV exhibits an intimate relationship with the host immune system, and is therefore of great interest to immunologists. In this review, a summary is given of recent developments in our understanding of the interaction between CMV and the host immune system and guidelines are provided for the clinical management of this infection.

Implications for Mantle Dynamics from the High Melting Temperature of Perovskite

Recent studies have implied that (Mg, Fe)SiO(3)-perovskite, a likely dominant mineral phase in the lower mantle, may have a high melting temperature. The implications of these findings for the dynamics of the lower mantle were investigated with the use of numerical convection models. The results showed that low homologous temperatures (0.3 to 0.5) would prevail in the modeled lower mantle, regardless of the effective Rayleigh number and internal heating rates. High-temperature ductile creep is possible under relatively cold conditions. In models with low rates of internal heating, local maxima of viscosity developed in the mid-lower mantle that were similar to those obtained from inversion of geoid, topography, and plate velocities.