Jan N. M. IJzermans

Stereotactic body radiation therapy for primary and metastatic liver tumors: A single institution phase i-ii study

The feasibility, toxicity and tumor response of stereotactic body radiation therapy (SBRT) for treatment of primary and metastastic liver tumors was investigated. From October 2002 until June 2006, 25 patients not suitable for other local treatments were entered in the study. In total 45 lesions were treated, 34 metastases and 11 hepatocellular carcinoma (HCC). Median follow-up was 12.9 months (range 0.5–31). Median lesion size was 3.2 cm (range 0.5–7.2) and median volume 22.2 cm3 (range 1.1–322). Patients with metastases, HCC without cirrhosis, and HCC < 4 cm with cirrhosis were mostly treated with 3×12.5 Gy. Patients with HCC ≥4cm and cirrhosis received 5×5 Gy or 3×10 Gy. The prescription isodose was 65%. Acute toxicity was scored following the Common Toxicity Criteria and late toxicity with the SOMA/LENT classification. Local failures were observed in two HCC and two metastases. Local control rates at 1 and 2 years for the whole group were 94% and 82%. Acute toxicity grade ≥3 was seen in four patients; one HCC patient with Child B developed a liver failure together with an infection and died (grade 5), two metastases patients presented elevation of gamma glutamyl transferase (grade 3) and another asthenia (grade 3). Late toxicity was observed in one metastases patient who developed a portal hypertension syndrome with melena (grade 3). SBRT was feasible, with acceptable toxicity and encouraging local control. Optimal dose-fractionation schemes for HCC with cirrhosis have to be found. Extreme caution should be used for patients with Child B because of a high toxicity risk.

Long-term culture of genome-stable bipotent stem cells from adult human liver

Summary Despite the enormous replication potential of the human liver, there are currently no culture systems available that sustain hepatocyte replication and/or function in vitro. We have shown previously that single mouse Lgr5+ liver stem cells can be expanded as epithelial organoids in vitro and can be differentiated into functional hepatocytes in vitro and in vivo. We now describe conditions allowing long-term expansion of adult bile duct-derived bipotent progenitor cells from human liver. The expanded cells are highly stable at the chromosome and structural level, while single base changes occur at very low rates. The cells can readily be converted into functional hepatocytes in vitro and upon transplantation in vivo. Organoids from α1-antitrypsin deficiency and Alagille syndrome patients mirror the in vivo pathology. Clonal long-term expansion of primary adult liver stem cells opens up experimental avenues for disease modeling, toxicology studies, regenerative medicine, and gene therapy.

Proteinuria after renal transplantation affects not only graft survival but also patient survival

Background. Proteinuria is associated with an increased risk of renal failure. Moreover, proteinuria is associated with an increased death risk in patients with diabetes mellitus or hypertension and even in the general population. Methods. One year after renal transplantation, we studied the influence of the presence of proteinuria on the risk of either graft failure or death in all 722 recipients of a kidney graft in our center who survived at least 1 year with a functioning graft. Proteinuria was analyzed both as a categorical variable (presence versus absence) and as a continuous variable (quantification of 24 hr urine). Other variables included in this analysis were: donor/recipient age and gender, original disease, race, number of HLA-A and HLA-B mismatches, previous transplants, postmortal or living related transplantation, and transplantation year. At 1 year after transplantation, we included: proteinuria, serum cholesterol, serum creatinine, blood pressure, and the use of antihypertensive medication. Results. In the Cox proportional hazards analysis, proteinuria at 1 year after transplantation (both as a categorical and continuous variable) was an important and independent variable influencing all endpoints. The influence of proteinuria as a categorical variable on graft failure censored for death showed no interaction with any of the other variables. There was an adverse effect of the presence of proteinuria on the graft failure rate (RR=2.03). The influence of proteinuria as a continuous variable showed interaction with original disease. The presence of glomerulonephritis, hypertension, and systemic diseases as the original disease significantly increased the risk of graft failure with an increasing amount of proteinuria at 1 year. The influence of proteinuria as a categorical variable on the rate ratio for patient failure was significant, and there was no interaction with any of the other significant variables (RR=1.98). The death risk was almost twice as high for patients with proteinuria at 1 year compared with patients without proteinuria. The influence of proteinuria as a continuous variable was also significant and also without interaction with other variables. The death risk increased with increasing amounts of proteinuria at 1 year. Both the risks for cardiovascular and for noncardiovascular death were increased. Conclusion. Proteinuria after renal transplantation increases both the risk for graft failure and the risk for death.

Comparison of laparoscopic and mini incision open donor nephrectomy: single blind, randomised controlled clinical trial.

Abstract Objectives To determine the best approach for live donor nephrectomy to minimise discomfort to the donor and to provide good graft function. Design Single blind, randomised controlled trial. Setting Two university medical centres, the Netherlands. Participants 100 living kidney donors. Interventions Participants were randomly assigned to either laparoscopic donor nephrectomy or to mini incision muscle splitting open donor nephrectomy. Main outcome measures The primary outcome was physical fatigue using the multidimensional fatigue inventory 20 (MFI-20). Secondary outcomes were physical function using the SF-36, hospital stay after surgery, pain, operating times, recipient graft function, and graft survival. Results Conversions did not occur. Compared with mini incision open donor nephrectomy, laparoscopic donor nephrectomy resulted in longer skin to skin time (median 221 v 164 minutes, P < 0.001), longer warm ischaemia time (6 v 3 minutes, P < 0.001), less blood loss (100 v 240 ml, P < 0.001), and a similar number of complications (intraoperatively 12% v 6%, P = 0.49, postoperatively both 6%). After laparoscopic nephrectomy, donors required less morphine (16 v 25 mg, P = 0.005) and shorter hospital stay (3 v 4 days, P = 0.003). During one years follow-up mean physical fatigue was less (difference - 1.3, 95% confidence interval - 2.4 to - 0.1) and physical function was better (difference 6.2, 2.0 to 10.3) after laparoscopic nephrectomy. Function of the graft and graft survival rate of the recipient at one year censored for death did not differ (100% after laparoscopic nephrectomy and 98% after open nephrectomy). Conclusions Laparoscopic donor nephrectomy results in a better quality of life compared with mini incision open donor nephrectomy but equal safety and graft function.

Systematic review and meta-analysis of steatosis as a risk factor in major hepatic resection.

The risk of major hepatic resection in patients with hepatic steatosis remains controversial. A meta‐analysis was performed to establish the best estimate of the impact of steatosis on patient outcome following major hepatic surgery.

Is perioperative chemotherapy useful for solitary, metachronous, colorectal liver metastases?

Background:Chemotherapy is increasingly used in colorectal liver metastases (CRLMs) even when they are initially resectable. The aim of our study was to address the still pending question of whether perioperative chemotherapy is really beneficial in patients developing solitary metastases at a distance from surgery of the primary. Methods:We analyzed a multicentric cohort of 1471 patients resected for solitary, metachronous, primarily resectable CRLMs without extrahepatic disease in the LiverMetSurvey International Registry over a 15-year period. Patients who received at least 3 cycles of oxaliplatin- or irinotecan-based chemotherapy before liver surgery (group CS, n = 169) were compared with those who were resected upfront (group S, n = 1302). Results:Patients of group CS were more frequently females (49% vs 36%, P = 0.001) and had larger metastases (≥5 cm, 33% vs 23%, P = 0.007); no difference was observed with regard to age, site of the primary tumour, time delay to occurrence of metastases, and carcinoembryonic antigen (CEA) levels at the time of diagnosis in the 2 groups. The rate of postoperative complications was significantly higher in group CS (37.2% vs 24% in group S, P = 0.006). At univariate analysis, preoperative chemotherapy did not impact the overall survival (OS) (60% at 5 years in both groups); however, postoperative chemotherapy was associated with better OS (65% vs 55% at 5 years, P < 0.01). At multivariate analysis, age 70 years or older (P = 0.05), lymph node positivity in the primary tumor (P = 0.02), a primary-to-metastases time delay of less than 12 months (P = 0.04), raised CEA levels of more than 5 ng/mL at diagnosis (P < 0.01), a tumor diameter of 5 cm or more (P < 0.01), noncurative liver resection (P < 0.01), and the absence of postoperative chemotherapy (P < 0.01) were independent prognostic factors of survival. The disease-free survival (DFS) was negatively influenced by CEA level of more than 5 ng/mL (P < 0.01), size of the metastases 5 cm or more (P = 0.05), and the absence of postoperative chemotherapy (P < 0.01). When patients with metastases of less than 5 cm in size were compared to those with metastases of size 5 cm or more, preoperative chemotherapy did not influence the OS or DFS in either group. Postoperative chemotherapy, on the other hand, improved OS and DFS in patients with metastases of size 5 cm or more but not in patients with metastases of less than 5 cm in size. Conclusions:Although preoperative chemotherapy does not seem to benefit the outcome of patients with solitary, metachronous CRLM, postoperative chemotherapy is associated with better OS and DFS, mainly when the tumor diameter exceeds 5 cm.

Tissue-specific mutation accumulation in human adult stem cells during life

The gradual accumulation of genetic mutations in human adult stem cells (ASCs) during life is associated with various age-related diseases, including cancer. Extreme variation in cancer risk across tissues was recently proposed to depend on the lifetime number of ASC divisions, owing to unavoidable random mutations that arise during DNA replication. However, the rates and patterns of mutations in normal ASCs remain unknown. Here we determine genome-wide mutation patterns in ASCs of the small intestine, colon and liver of human donors with ages ranging from 3 to 87 years by sequencing clonal organoid cultures derived from primary multipotent cells. Our results show that mutations accumulate steadily over time in all of the assessed tissue types, at a rate of approximately 40 novel mutations per year, despite the large variation in cancer incidence among these tissues. Liver ASCs, however, have different mutation spectra compared to those of the colon and small intestine. Mutational signature analysis reveals that this difference can be attributed to spontaneous deamination of methylated cytosine residues in the colon and small intestine, probably reflecting their high ASC division rate. In liver, a signature with an as-yet-unknown underlying mechanism is predominant. Mutation spectra of driver genes in cancer show high similarity to the tissue-specific ASC mutation spectra, suggesting that intrinsic mutational processes in ASCs can initiate tumorigenesis. Notably, the inter-individual variation in mutation rate and spectra are low, suggesting tissue-specific activity of common mutational processes throughout life.

Short‐term dietary restriction and fasting precondition against ischemia reperfusion injury in mice

Dietary restriction (DR) extends lifespan and increases resistance to multiple forms of stress, including ischemia reperfusion injury to the brain and heart in rodents. While maximal effects on lifespan require long‐term restriction, the kinetics of onset of benefits against acute stress is not known. Here, we show that 2–4 weeks of 30% DR improved survival and kidney function following renal ischemia reperfusion injury in mice. Brief periods of water‐only fasting were similarly effective at protecting against ischemic damage. Significant protection occurred within 1 day, persisted for several days beyond the fasting period and extended to another organ, the liver. Protection by both short‐term DR and fasting correlated with improved insulin sensitivity, increased expression of markers of antioxidant defense and reduced expression of markers of inflammation and insulin/insulin‐like growth factor‐1 signaling. Unbiased transcriptional profiling of kidneys from mice subject to short‐term DR or fasting revealed a significant enrichment of signature genes of long‐term DR. These data demonstrate that brief periods of reduced food intake, including short‐term daily restriction and fasting, can increase resistance to ischemia reperfusion injury in rodents and suggest a rapid onset of benefits of DR in mammals.

Inflammatory conditions affect gene expression and function of human adipose tissue-derived mesenchymal stem cells

There is emerging interest in the application of mesenchymal stem cells (MSC) for the prevention and treatment of autoimmune diseases, graft‐versus‐host disease and allograft rejection. It is, however, unknown how inflammatory conditions affect phenotype and function of MSC. Adipose tissue‐derived mesenchymal stem cells (ASC) were cultured with alloactivated peripheral blood mononuclear cells (PBMC) (mixed lymphocyte reaction: MLR), with proinflammatory cytokines [interferon (IFN)‐γ, tumour necrosis factor (TNF)‐α and interleukin (IL)‐6] or under control conditions, and their full genome expression and function examined. Proinflammatory cytokines mainly increased indoleamine‐2,3‐dioxygenase expression, whereas ASC cultured with MLR showed increased expression of COX‐2, involved in prostaglandin E2 production. Both conditions had a stimulatory, but differential, effect on the expression of proinflammatory cytokines and chemokines, while the expression of fibrotic factors was decreased only in response to proinflammatory cytokines. Functional analysis demonstrated that inflammatory conditions affected morphology and proliferation of ASC, while their differentiation capacity and production of trophic factors was unaffected. The immunosuppressive capacity of ASC was enhanced strongly under inflammatory conditions. In conclusion, ASC showed enhanced immunosuppressive capacity under inflammatory conditions, while their differentiation capacity was preserved. Therefore, in vitro preconditioning provides ASC with improved properties for immediate clinical immune therapy.

Hepatocellular Adenomas: Correlation of MR Imaging Findings with Pathologic Subtype Classification

PURPOSE To investigate the correlation between magnetic resonance (MR) imaging findings and pathologic subtype classification of hepatocellular adenoma (HCA). MATERIALS AND METHODS This retrospective study was approved by the institutional review board, and the requirement for informed consent was waived. MR imaging studies of 61 lesions (48 patients; median age, 36 years) were available and were independently reviewed by two radiologists. Consensus readings on all morphologic and signal-intensity imaging features were obtained. Previously, these lesions had been classified on the basis of pathologic findings and immunohistochemical analysis. Fisher exact and χ² tests were performed to compare the results between the different subtypes. A Bonferroni correction was applied to correct for multiple testing (α < .0033). RESULTS MR imaging signs of diffuse intratumoral fat deposition were present in seven (78%) of nine liver-fatty acid binding protein (L-FABP)-negative HCAs compared with five (17%) of 29 inflammatory HCAs (P = .001). Steatosis within the nontumoral liver was present in 11 (38%) of 29 inflammatory HCAs compared with none of the L-FABP-negative HCAs (P = .038). A characteristic atoll sign was only seen in the inflammatory group (P = .027). Presence of a typical vaguely defined type of scar was seen in five (71%) of seven β-catenin-positive HCAs (P = .003). No specific MR imaging features were identified for the unclassified cases. CONCLUSION L-FABP-negative, inflammatory, and β-catenin-positive HCAs were related to MR imaging signs of diffuse intratumoral fat deposition, an atoll sign, and a typical vaguely defined scar, respectively. Since β-catenin-positive HCAs are considered premalignant, closer follow-up with MR imaging or resection may be preferred.