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Biomedical subjects

M J Slooff

Publications and source records attributed to M J Slooff.

At least 37 records · Page 2Linked to original sources

Predictive factors for portal fibrosis in pediatric liver transplant recipients.

BACKGROUND: Recent histopathological studies showed an unexpected high incidence of pathological changes in asymptomatic survivors after pediatric liver transplantation. The aim of this study was to analyze the occurrence of histological abnormalities, to assess the clinical significance, and to identify predictive factors for these pathological changes. METHODS: The first annual protocol graft biopsies of 84 consecutive liver transplants were analyzed and correlated with concomitant liver function tests. Identification of predictive factors for the histological abnormalities in the biopsies was performed by a multivariate logistic regression analysis. RESULTS: The incidence of portal fibrosis (PF) was 31%. Liver function tests showed except for the albumin level, an increase in the PF group compared with the group without PF. Mean values of alkaline phosphatase and direct bilirubin were 264 U/liter and 3 micromol/liter, respectively, in the normal group, and 435 U/liter and 23 micromol/liter, respectively, in the PF group (P=0.043 and 0.037). Eight of 19 univariantly tested variables were entered into a logistic regression model: cold ischemia time, preservation solution, type of allograft, cytomegalovirus recipient status, type of biliary reconstruction, biliary complications, graft complications, and rejection. A significant positive correlation with PF was found for cold ischemia time, biliary complications, and cytomegalovirus status. Acute rejection showed a negative correlation. CONCLUSIONS: The incidence of PF within 1 year post liver transplantation was 31%. This finding was accompanied by cholestatic liver function test abnormalities. Factors predisposing to PF were a prolonged cold ischemia time, biliary complications, and a positive cytomegalovirus recipient status. Acute rejection seemed to prevent for PF.

Adolescent↗

Prognostic factors for long-term actual patient survival after orthotopic liver transplantation in children.

BACKGROUND: Orthotopic liver transplantation has become the treatment of choice for children with end-stage liver disease. Although results have improved the last decades, still a considerable number of children die after transplantation. The aim of this study was to analyze long-term actual survival and to identify prognostic factors for such survival rates. METHODS: A consecutive series of 66 children receiving transplants who had or could have had a follow-up of at least 5 years was retrospectively analyzed. Actual survival and prognostic factors in relation to patient, donor, and operation related variables were assessed after multivariate analysis. RESULTS: Actual 1-, 3-, and 5-year patient survival was 86%, 79%, and 73%, respectively. A high Child-Pugh (C-P) score or C-P class C, high donor age, high blood loss index, and retransplantation were predictive factors for actual patient survival. A high blood loss index was correlated with biliary atresia, low recipient age and weight, and with previous upper abdominal operations. The duration of stay of the donor at the intensive care unit (ICU) was a predictive factor for retransplantation. CONCLUSIONS: Children with diseases eligible for liver transplantation should be seen early in the course of their disease in a transplantation center. All possible measures should be taken during the transplantation procedure to keep the blood loss at a minimum. Children with biliary atresia deserve special attention in this respect. The choice of donors has implications for survival.

Adolescent↗

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.

Absorptiometry, Photon↗

End-stage liver disease as the only consequence of a mitochondrial respiratory chain deficiency: no contra-indication for liver transplantation.

UNLABELLED: The prerequisite for liver transplantation as a therapeutic option for inherited metabolic diseases should be that the enzyme defect, being responsible for the major clinical (hepatic and/or extra-hepatic) abnormalities, is localised in the liver. Furthermore, no adequate dietary or pharmacological treatment should be available or such treatment should have an unacceptable influence on the quality of life. We report an infant, who developed end-stage liver disease with persistent lactic acidaemia in his first months of life. Analysis of the mitochondrial respiratory chain in liver tissue revealed a combined partial complex I and IV deficiency. No extra-hepatic involvement could be demonstrated by careful screening for multiple organ involvement, including analysis of the mitochondrial respiratory chain in muscle tissue and cultured skin fibroblasts. The boy received a reduced size liver graft at the age of 8 months. He recovered successfully. Almost 5 years after transplantation he is in good clinical condition. No clinical or biochemical signs of any organ dysfunction have been demonstrated. The considerations on which basis it was decided that there was no contra-indication to perform liver transplantation in this patient are discussed. CONCLUSION: The possibility of a mitochondrial respiratory chain deficiency should be considered in liver disease of unknown origin prior to liver transplantation. Liver transplantation is a therapeutic option in mitochondrial respiratory chain deficiency-based end-stage liver disease provided that extra-hepatic involvement is carefully excluded.

Child, Preschool↗

Scanning electron microscopic analysis of endothelial cell coverage and quality in large vessels from multi-organ donors: effects of preservation on endothelial cell integrity.

Endothelial cell integrity (coverage and quality) of large donor vessels is important because these vessels are used for vascular reconstructions in solid-organ transplantation. Disruption of the endothelial cell monolayer will initiate blood coagulation and may lead to thrombosis of large vessels, often resulting in the loss of the transplanted organ. Iliac arteries and veins, removed from 10 heart-beating multi-organ donors at the end of the donor procedure, were analyzed using scanning electron microscopy at three different time points of preservation. Endothelial cell coverage and quality were determined immediately after removal from the donor, after 10 h (time of transplantation) and 7 d storage in 'University of Wisconsin' cold preservation solution (UW). Endothelial cell coverage decreased during the preservation of arteries, but was maintained in veins. Storage of the veins for 7 d in plastic bags showed a decreased endothelial cell coverage compared to storage in glass vials. Early removal of the blood vessels and proper storage, free floating and in clean UW, may improve maintenance of the endothelial cell integrity. These findings may be important in order to reduce the risk of thrombosis and, consequently, organ failure after transplantation. Furthermore, vessels with maintained endothelial cell integrity after 7 d may be used for in vitro research.

Adenosine↗

The capability of isolated hepatocytes and liver slices of donor livers to predict graft function after liver transplantation.

AIMS/BACKGROUND: In liver transplantation, adequate function tests for donor livers and transplanted livers are of utmost importance to provide an objective basis for decision-making. Isolated hepatocyte and/or slice preparations from human donor liver tissue may be suitable to test the quality of the organ to be transplanted. METHODS: Surgical waste material remaining after reduced size or split liver transplantation in children was used to prepare slices and isolated hepatocytes. The viability of these preparations as well as drug transport and metabolism functions were determined and related to graft function in 32 liver recipients. RESULTS: The in vitro tests used in the present study apparently did not select non-viable livers. In vitro preparations of the primary non-function grafts which occurred in the investigated group showed normal viability, metabolic and uptake function. CONCLUSION: These results indicate that either the presently used viability tests are not sensitive enough to detect potential organ failure or that other factors besides the hepatocyte viability at the time of transplantation are of paramount importance to the graft function of the recipient, such as complications during and after transplantation or the viability of the non-parenchymal cells.

Adenosine Triphosphate↗

Endotoxins and cytokines during liver transplantation: changes in plasma levels and effects on clinical outcome.

Endotoxins, tumor necrosis factor-alpha (TNF-alpha), interleukin-1 (IL-1), and IL-6 are believed to have a key role in liver transplantation. The origin and course of these factors is not completely known. In this prospective study of 40 patients, we sought more understanding of the relations between these factors and their effects on clinical outcome by sampling at different sites. Endotoxemia was only present in 20% of the patients. In 75% of these patients, it was present during the anhepatic phase and quickly resolved after reperfusion. Endotoxemia was not related to a clinical adverse event. TNF-alpha was released from the graft after reperfusion, and initial levels after reperfusion were related to predonation levels in the donor. Only levels of TNF-alpha in the recipient before transplantation were found to be predictive of postoperative complications. We conclude that monitoring endotoxins and these cytokines is of very limited value in predicting outcome.

Adult↗

Early vascular complications after pediatric liver transplantation.

Vascular complications have a detrimental effect on the outcome after liver transplantation. Most studies focus exclusively on hepatic artery thrombosis (HAT). The current study analyzed the incidence, consequences, and risk factors for HAT, portal vein thrombosis (PVT), and venous outflow tract obstruction (VOTO) in a consecutive series of 157 pediatric liver transplantations. The overall incidence of vascular complications was 21%. The incidences of HAT, PVT, and VOTO were 10%, 4%, and 6%, respectively. Patient survival after PVT and VOTO and graft survival after HAT and PVT were less compared with survival of grafts without vascular complications. To identify risk factors for vascular complications, factors related to recipient, donor, and surgical techniques were analyzed. A low donor-recipient (D/R) age ratio, long surgical time, and use of the proper hepatic artery of the recipient for arterial reconstruction were risk factors for HAT. Young age, low weight, segmental grafts, and piggyback technique were risk factors for PVT. Fulminant hepatic failure, high D/R age and weight ratios, and use of segmental grafts were related to VOTO. Vascular complications, which occurred in 21% of the pediatric liver transplantations, had a significant impact on patient and graft survival. Size disparity between donor and recipient was an important risk factor for vascular complications, especially in the case of transplantation of segmental grafts. Patient and graft survival might improve by avoiding the identified risk factors.

Adolescent↗

Blood loss in orthotopic liver transplantation: a retrospective analysis of transfusion requirements and the effects of autotransfusion of cell saver blood in 164 consecutive patients.

Liver transplantation is associated with excessive blood loss. In order to identify factors influencing blood loss and to provide a basis for a pilot study to evaluate recombinant activated factor VII as a haemostatic agent, a retrospective study was performed in 164 consecutive patients with cholestatic or noncholestatic liver disease, who underwent orthotopic liver transplantation at a single centre between 1989 and 1996. Transfusion of allogeneic and autologous (cell saver) blood was used as a measurement of blood loss. Transfusion requirements were associated with age, gender, primary disease, Child-Pugh classification, serum levels of activated partial thromboplastin time, antithrombin III, urea and creatinine, platelet number, year of transplantation, length of cold ischaemia time and autologous blood transfusion. Of these variables, Child-Pugh classification (P = 0.001), urea (P = 0.0007), year of transplantation (P = 0.002), cold ischaemia time (P = 0.01) and autologous blood transfusion (P < 0.0001) were independent predictors of transfusion requirements by multivariate analysis. Thus, blood loss and transfusion requirements depend primarily on the severity of liver disease, quality of the donor liver, experience of the transplantation team and use of autologous (cell saver) blood transfusion. These findings emphasize the need for appropriate drug therapy and a critical reappraisal of current transfusion policy.

Adult↗

Arteriography and portal venography on routine follow-up after orthotopic liver transplantation.

RATIONALE AND OBJECTIVES: To describe the findings of routinely performed angiographic examinations in patients at discharge 2 months after orthotopic liver transplantation (OLT) and at follow-up 1 year later. METHODS: The findings of 315 angiographic examinations performed in 190 patients 2 months and 1 year after OLT were reviewed, and the changes at the anastomotic site of the hepatic artery and portal vein were analyzed. RESULTS: Routine angiography 2 months and 1 year after OLT demonstrated a normal anastomosis or low-grade stenosis in 82% and 84% of the patients (hepatic artery) and in 88% and 84% (portal vein), respectively. High-grade stenosis occurred in 9% and 5% of the patients (hepatic artery) and in 3% and 5% (portal vein). Hepatic artery occlusion and portal vein occlusion were observed in two and seven patients and in one and three patients, respectively. In 76% of patients, the anastomotic site of the hepatic artery did not change significantly. In eight patients, a normal anastomosis or a low- or medium-grade stenosis developed into high-grade stenosis or occlusion. Conversely, in nine patients, medium- or high-grade stenosis developed into a normal anastomosis or a low-grade stenosis. In all eight patients who initially had a high-grade stenosis, the hepatic artery proved to be patent at 1 year. In 98% of patients, the anastomotic site of the portal vein did not change significantly. In one patient who initially had a normal anastomosis, occlusion was found at I year. CONCLUSIONS: In most patients, routine angiography 2 months and 1 year after OLT demonstrated normal findings or a low-grade stenotic anastomosis of the hepatic artery and portal vein. Significant changes occurred mainly at the anastomotic site of the hepatic artery and could not be predicted by previous angiograms.

Adult↗

Experimental autologous substitute vascular graft for transplantation surgery.

Vascular complications in liver transplantation are a major cause of graft failure and mortality. The aim of the study was to create autologous vascular graft without risk of rejection. Posterior rectus fascia sheath lined with peritoneum was used for iliac artery replacement in seven mongrel dogs. The patency was followed by palpation and Doppler ultrasound. The grafts were removed after one month. Five grafts remained patent. The Doppler showed good, relatively increased flow (median flow rate: 383 cm/sec) after one month in all of the cases. Slight increase in diameter was present in all cases. By microscopy the five patent grafts showed viable morphology, fibroblasts, smooth muscle cells and thin fibrin layer in the wall. The grafts were lined partially with a neoendothelial monolayer and a thin fibrin layer. In conclusion, this graft presents an acceptable patency rate and low thrombogenicity, and could be useful in transplantation. Further investigations are needed to study the effect of immunosuppression and rejection on long-term morphology and patency of the grafts.

Animals↗

Analysis of survival and morbidity after pediatric liver transplantation with full-size and technical-variant grafts.

BACKGROUND: To alleviate the shortage of size-matched whole-donor organs, too-large-for-size cadaveric donor grafts are modified by liver resection techniques. These modifications result in technical-variant liver transplantation (TVLTx). Patient and graft survival rates after TVLTx are considered comparable to those after full-size liver transplantation (FSLTx). However, morbidity after TVLTx is often underexposed. The aim of this study was to analyze the results of FSLTx and TVLTx in terms of patient and graft survival rates and morbidity. METHODS: A consecutive series of 97 primary and elective pediatric liver transplantations performed in a single center was retrospectively analyzed. Forty-seven children had a FSLTx and 50 a TVLTx (38 reduced-size liver grafts and 12 split-liver grafts). The overall median follow-up period was 3.5 years. RESULTS: There were no differences in patient and graft survival rates between FSLTx and TVLTx. However, after TVLTx there was a significantly higher complication rate (1.42 vs. 0.81 after FSLTx). TVLTx is more hampered by biliary complications (30% vs. 17%), expressed by a higher incidence of cholangitis and leakage of bile. These complications led to a significantly higher incidence of sepsis (44% vs. 19%) and a significantly higher intervention rate (0.40 vs. 1.28) after TVLTx. There was no difference in the incidence of retransplantations between FSLTx and TVLTx. CONCLUSIONS: Both FSLTx and TVLTx offer the same prognosis in terms of patient and graft survival rates for children after a primary and elective liver transplantation. However, TVLTx has a higher morbidity.

Adolescent↗

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.

Adolescent↗

Long-term follow-up after liver transplantation for erythropoietic protoporphyria.

OBJECTIVE: Erythropoietic protoporphyria (EPP) is an inherited disorder of haem synthesis, causing excess of protoporphyrin in blood, skin, liver and other organs. Protoporphyrin causes rapidly progressive liver failure in a minority of EPP patients. Long-term follow-up after liver transplantation for EPP is poorly documented. DESIGN: Two EPP patients were followed for 7 years after liver transplantation. Porphyrin levels were monitored and serial liver biopsies were taken. RESULTS: After transplantation, serum protoporphyrin levels remained elevated. In one patient, long periods with normal liver tests, low protoporphyrin levels and the absence of photosensitivity were followed by episodes of cholestasis and elevated protoporphyrin levels in blood, faeces and liver tissue. These episodes could be managed successfully with blood transfusions and changes in medication. The simultaneous rise of protoporphyrin concentration in both blood and faeces in this patient argues for increased protoporphyrin production as the cause of liver cell injury. The other patient acquired hepatitis B infection during the transplantation. From 3 months onwards she had continuously elevated liver tests, cholestasis, elevated protoporphyrin levels in blood, faeces and liver tissue, and photosensitivity. In this case, cholestasis and impaired protoporphyrin excretion may have played an important role in the persistent liver injury. Sequential liver biopsies of both patients showed various degrees of liver injury related to variations of the hepatic protoporphyrin concentrations. Eight and six months respectively after liver transplantation the livers of both patients showed fibrosis and hepatocellular protoporphyrin accumulation. CONCLUSIONS: The main cause of liver damage in EPP is overproduction of protoporphyrin in the bone marrow. Liver transplantation must be considered as symptomatic therapy with a high-risk for recurrent disease.

Adult↗

Ochrobactrum intermedium infection after liver transplantation.

A case of bacteremia due to Ochrobactrum intermedium, with concomitant liver abscesses, in an orthotopic liver transplant recipient is presented. Identical microorganisms were isolated from fecal specimens and from an aspirate of a liver abscess that was indicative of invasion of the graft by gastrointestinal spread. 16S DNA sequence analysis of the blood isolate revealed the recovery of the recently proposed new species O. intermedium, closely related to Ochrobactrum anthropi and Brucella spp.

Anti-Bacterial Agents↗

[3H]thymidine incorporation into whole liver as an alternative to [3H]thymidine incorporation into DNA as a parameter of cell proliferation in regenerating liver tissue in rats.

OBJECTIVE: To monitor liver regeneration following partial hepatectomy, liver cell proliferation can be measured by assaying in vivo [3H]thymidine incorporation into liver cell DNA. We hypothesized that [3H]thymidine incorporation into whole liver tissue parallels [3H]thymidine incorporation into liver cell DNA, both in high proliferating and low proliferating liver. STUDY DESIGN: Liver cell proliferation in rats after partial hepatectomy or a sham operation was studied by measuring incorporation of [3H]thymidine into various fractions of liver tissue on days 1, 2, 3, 4 and 10 after surgery. RESULTS: [3H]thymidine incorporation into whole liver tissue and in the protein fraction correlated well with DNA-specific [3H]thymidine incorporation into regenerating (r > .80, P < .0001) and nonregenerating liver (r > .69, P < .005). [3H]thymidine incorporation into DNA was < 5% of the total amount of administered [3H]thymidine in both sham-operated and hepatectomized rats. Significant differences in [3H]thymidine incorporation into partially hepatectomized livers as compared to sham-operated rat livers were found on days 1 and 2 (whole liver tissue and protein fraction) or day 1 (DNA) after surgery. CONCLUSION: [3H]thymidine incorporation into whole liver tissue is a simple technique that can be used for the study of liver cell proliferation after partial hepatectomy in rats.

Animals↗

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.

Humans↗