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Biomedical subjects

Philippe Wolf

Publications and source records attributed to Philippe Wolf.

At least 19 recordsLinked to original sources

Long-term survival in post-transplant lymphoproliferative disorders with a dose-adjusted ACVBP regimen.

Post-transplant lymphoproliferative disorders (PTLD) are severe complications after solid organ transplantation with no consensus on best treatment practice. Chemotherapy is a therapeutic option with a high response and a significant relapse rate leading to a low long-term tolerance rate. Currently, most centres use anthracycline-based drug combinations, such as CHOP (cyclophosphamide, doxorubicin, vincristine and prednisone). We assessed the efficacy and safety of a dose-adjusted ACVBP (doxorubicin reduced to 50 mg/m(2), cyclophosphamide adjusted to renal function, vindesine, bleomycin, prednisone) regimen in patients failing to respond to a reduction in immunosuppressive therapy. Favourable responses were observed in 24 (73%) of the 33 treated patients. Fourteen (42%) patients died, mostly from PTLD progression. Actuarial survival was 60% at 5 years and 55% at 10 years. Survival prognostic factors were: number of involved sites (P = 0.007), clinical stage III/IV (P = 0.004), bulky tumour (P < 0.0001), B symptoms (P = 0.03), decreased serum albumin (P = 0.03) and poor performance status (P = 0.06). Both the international and the PTLD prognostic index were predictive for survival (P = 0.001 and P = 0.002, respectively). Overall 128 cycles were given. Grade 3 or 4 neutropenia was recorded after 26 (20%) chemotherapy cycles in 19 (58%) patients. Forty-one (32%) infections were recorded in 26 (79%) patients. This study demonstrated that an individual dose-adjustment of ACVBP regimen was manageable in PTLD patients and favourably impacted on long-term survival.

Adolescent↗

Early decrease in circulating dendritic cells number after liver transplantation could favor hepatitis C virus recurrence.

Cirrhosis and hepatocarcinoma related to hepatitis C virus (HCV) lead to more than 30% of liver transplantations. Host- and virus-related mechanisms, involved in the recurrence of HCV infection of the liver graft, are not yet well known. A weak CD4+ T-cell response was shown to be involved in the outcome of re-infection but whether dendritic cell numbers are modified in patients transplanted for HCV-related disease has never been evaluated. Eight transplanted patients for HCV-related disease and eight non-HCV-infected transplanted controls were included. Blood plasmacytoid dendritic cells and myeloid dendritic cells were quantified before transplantation, at day 7 and 1 month after transplantation. Plasma interferon (IFN)-alpha and interleukin (IL)-12 were concomitantly measured. The results showed a significant decrease in the relative (P < 0.0001) and absolute (P = 0.0002) values of blood plasmacytoid dendritic cells at day 7 after transplantation when compared to the values obtained before transplantation, increasing again 1 month later, in both HCV-infected patients and controls. The same tendency was observed for myeloid dendritic cell relative values (P = 0.0004) and plasma IL-12 (P < 0.05). IFN-alpha appeared to be less often detectable for HCV-infected patients. These results obtained on dendritic cell numbers could explain partially the early and systematic recurrence of HCV infection on the liver graft and contribute to better adapted therapeutic strategies.

Cell Count↗

Simultaneous development of lymphoma in recipients of renal transplants from a single donor: donor origin confirmed by human leukocyte antigen staining and microsatellite analysis.

BACKGROUND: Posttransplant lymphoproliferative disorders (PTLD) occur in 0.5% to 2.5% of cases in renal-transplant recipients. Epstein-Barr virus (EBV) is usually detected in the tumor cells, suggesting a role for this virus as an agent of B-cell proliferation. It is unusual for patients receiving allografts from the same donor to develop PTLD simultaneously. METHODS: we describe two patients who received renal allografts from the same donor and developed PTLD simultaneously. The presence of EBV in both tumors was confirmed. In this report, the origin of tumor cells was determined by immunohistochemical human leukocyte antigen (HLA) typing and microsatellite analysis. Clonality was studied by immunoglobulin gene rearrangement analysis. RESULTS: Our results suggest that the tumor originated from donor cells in both patients but, because immunoglobulin gene rearrangements were different, this could mean that lymphoid cells proliferate independently in each recipient. CONCLUSIONS: We propose the following pathogenesis: immortalization of passenger B lymphocytes by EBV, proliferation of these cells, and development of PTLD by means of immunosuppression, antigenic stimulation, and HLA mismatch.

Adult↗

Surgical resection of hepatocellular carcinoma. Post-operative outcome and long-term results in Europe: an overview.

A multicenter retrospective review of 1467 patients treated by liver resection (LR) for hepatocellular carcinoma (HCC) in Europe over a 13-year period showed a mean mortality rate of 10.6%, which was correlated with the extent of LR, the etiology of cirrhosis and the study period with an improvement during the last years. Improved 5-year overall survival (20-51%) and disease-free survival (20-33%) reached similar rates in cirrhotic than in non-cirrhotic patients. Overall results were similar to those reported in Asian series as far as patients and tumor characteristics were comparable.

Adult↗

A three-arm study comparing immediate tacrolimus therapy with antithymocyte globulin induction therapy followed by tacrolimus or cyclosporine A in adult renal transplant recipients.

BACKGROUND: Induction therapy with antithymocyte globulin (ATG) reduces the incidence of acute rejection after transplantation. A study was undertaken to assess the efficacy and safety of ATG induction on tacrolimus-based and cyclosporine A (CsA)-based therapies compared with immediate tacrolimus triple therapy in kidney transplant recipients. METHODS: In a 6-month, open-label, randomized, prospective study conducted in 30 European centers, 555 renal transplant patients were randomly assigned to tacrolimus triple therapy (Tac triple, n=185), ATG induction with tacrolimus (ATG-Tac, n=186), or ATG induction with CsA microemulsion (ATG-CsA, n=184); all were combined with azathioprine and corticosteroids. The primary endpoint was incidence and time to first acute rejection episode confirmed by biopsy. RESULTS: Patient demographics and clinical parameters at baseline were similar. Patient and graft survival rates were similar in all groups. The incidence of clinically apparent acute rejection was significantly higher (P=0.003) for Tac triple (33.0%) compared with ATG-Tac (22.6%) and the incidence for ATG-Tac was significantly lower (P=0.004) than for ATG-CsA (37.0%). The incidences of acute rejection confirmed by biopsy (primary endpoint) were 25.4%, 15.1%, and 21.2% for Tac triple, ATG-Tac, and ATG-CsA, respectively (Tac triple vs. ATG-Tac, P=0.004). The incidences of corticosteroid-resistant acute rejection were 7.0% (Tac triple), 4.8% (ATG-Tac), and 10.9% (ATG-CsA) (ATG-Tac vs. ATG-CsA, P=0.038). In the ATG groups, the incidences of leukopenia, thrombocytopenia, serum sickness, fever, and cytomegalovirus infection were significantly higher (P<0.05). CONCLUSIONS: Acute rejection was significantly lower in the ATG-Tac group compared with the ATG-CsA and Tac triple groups. Significantly more hematologic and infectious adverse events were observed in both ATG induction groups.

Acute Disease↗

Cyclooxygenase-2 and inducible nitric oxide synthase in omental arteries harvested from patients with severe liver diseases: immuno-localization and influence on vascular tone.

OBJECTIVE: To investigate the expression of inducible cyclooxygenase (COX-2) and inducible nitric oxide synthase (iNOS) and the role of vasodilatory prostanoids and endogenous nitric oxide (NO) in small omental arteries harvested from patients with severe liver diseases. DESIGN: Ex vivo study of resistance arteries. SETTING. Intensive care unit. PATIENTS: Twenty patients undergoing liver transplantation for fulminant hepatic failure (FHF, n=6), cirrhogenous viral hepatitis (CH, n=6) and limited hepatocarcinoma (controls, n=8). INTERVENTIONS: Western blot and immunohistochemical labeling for assessment of COX-2 and iNOS expression and localization and ex vivo vascular reactivity studies. MEASUREMENTS AND RESULTS: Significant upregulation of COX-2 and iNOS expressions were detected in arteries from FHF and CH patients with a greater increase in the former than in the latter. Ex vivo contractile responses to norepinephrine and the thromboxane A(2) analog, U46619, were not significantly different between patients with severe liver dysfunction and controls. Exposure to either the NO-synthase inhibitor, N(G)-nitro-L-arginine methyl ester (L-NAME), the cyclooxygenase inhibitor, indomethacin, or their combination did not significantly modify contractions of agonists in controls and CH patients. In FHF, the specific COX-2 inhibitor, N-(2-cyclohexyloxy-4-nitrophenyl) methanesulfonamide (1 micro m/l), but not L-NAME, significantly enhanced the maximal effect ( p<0.01) and the sensitivity ( p<0.01) to norepinephrine. CONCLUSIONS: COX-2 and iNOS are upregulated in omental arteries from patients with cirrhogenous hepatitis and fulminant hepatic failure. Whereas neither NO nor vasodilatory prostaglandins seem to play a major role in counteracting arterial contractility of arteries from control patients, COX-2 derivatives are involved in lowering the arterial contractility of vessels harvested from FHF patients.

Adult↗

One or two-stage hepatectomy combined with portal vein embolization for initially nonresectable colorectal liver metastases.

BACKGROUND: Portal vein embolization (PVE), proposed to induce contralateral hepatic hypertrophy before major hepatectomy, carries some negative side effects since growth rate of metastases in the future remnant liver (RL) can be more rapid than that of nontumoral liver parenchyma. Therefore, metastases in the RL should be ideally resected before PVE, and a major hepatectomy can then be performed after PVE in patients with multiple bilobar colorectal liver metastases (MBLM). The aim of this study was to assess feasibility and outcome in patients with initially unresectable colorectal liver metastases treated by a one- or two-stage hepatectomy procedure (TSHP) combined with PVE. PATIENTS AND METHODS: From December 1996 to December 1999, 180 patients with colorectal liver metastases underwent hepatectomy. During the same period, 18 were initially considered as unresectable. TSHP combined with PVE was attempted for 7 patients (group A) among those with MBLM, and a one-stage hepatectomy after PVE was attempted in another group of 11 patients (group B) among those with non-MBLM. RESULTS: Nonanatomical resections for left liver metastases were performed as a first stage without any complications in group A. A right hepatectomy (RH) was performed in 5 patients in group A (feasibility = 71%). In group B, 7 of the 11 patients underwent a RH or an extended RH after PVE (feasibility = 64%). Postoperative complications rate did not differ between group A and B. Mortality was nil. Three-year survival rate was 53% in group A and 100% in group B. CONCLUSIONS: These results suggest that one- or two-stage hepatectomy combined with PVE can be applied safely to selected patients initially considered as unresectable. Three-year survival was similar to that observed in patients with initially resectable liver metastases.

Colorectal Neoplasms↗

Hepatocyte ploidy in normal young rat.

The aim of the present study was to examine the relation between hepatocyte size and ploidy in Sprague-Dawley rat liver. Therefore, subpopulations of hepatocytes of various sizes were separated from the isolated crude hepatocyte population either mechanically or by using centrifugal elutriation. Hepatocyte size was determined on scanning electron microscopy photographs. Ploidy of hepatocytes was assessed by flow cytometry. The crude hepatocyte population was very heterogeneous in sizes, with diameters ranging from 8 to 39 microm. Hepatocyte ultrastructure was well preserved as demonstrated by transmission electron microscopy. The distribution of hepatocytes within the ploidy classes was the following: 19.6+/-3.6% diploid, 56.2+/-3.2% tetraploid and 3.4+/-0.6% octoploid mononucleated cells. Thus approximately 79% of hepatocytes appeared mononucleated. The binucleated hepatocytes (21%) had two diploid nuclei (18.7+/-2.9%) or two tetraploid nuclei (2.1+/-0.6%). A similar distribution of hepatocytes into ploidy classes was obtained in subpopulations of hepatocytes of various sizes. Our findings suggest that distribution into ploidy classes is not strictly correlated with hepatocyte size. In accordance with previous observations, our results on hepatocyte ploidy from periportal or perivenous origin using digitonin perfusion, is in favour of the existence of ploidy zonation within the rat hepatic lobule.

Aging↗

Small hepatocellular carcinoma in Child A cirrhotic patients: hepatic resection versus transplantation.

Hepatic resection (HR) is the treatment of choice for small hepatocellular carcinoma (HCC) in a noncirrhotic liver, whereas liver transplantation (LT) offers better results in patients with impaired hepatic function (Child B and C). However, it is still debated whether HR or LT is the best strategy for patients with Child A cirrhosis. We conducted a retrospective study on 37 consecutive patients with Child A cirrhosis and small HCC, treated between 1991 and 1999. Seventeen of these patients, who underwent LT, were compared with 20 patients who underwent HR, and prognostic factors for survival and tumor recurrence were analyzed. The primary endpoints were the intention-to-treat, 3- and 5-year survival, and 3- and 5-year recurrence-free survival. Three- and 5-year patient survival rate both were significantly (P =.04) higher in the LT group (87% and 71%, respectively) than in the HR group (67 and 36% respectively). Similarly, the 3- and 5- year recurrence-free survival rates were 87% and 80% for the LT group, and 52% and 40% for the HR group (P =.03). Absence of microscopic vascular invasion was the only other prognostic factor correlated with significantly better recurrence-free survival (P =.02). Therefore, we concluded that in patients with Child A cirrhosis and small HCC, liver transplantation resulted in better overall and disease-free survival than HR.

Aged↗

Significance of hepatic pedicle lymph node involvement in patients with colorectal liver metastases: a prospective study.

BACKGROUND: We investigated whether hepatic pedicle lymph node (HP-LN) involvement is a more significant prognostic factor and whether HP-LN dissection could be efficient in patients with positive HP-LN involvement. METHODS: From 1988 to 1998, HP-LN dissection was prospectively performed in 160 patients undergoing hepatectomy for colorectal liver metastases. Survival of patients with HP-LN involvement limited to the hepatoduodenal ligament and retropancreatic portion (area 1) was compared with that of patients with HP-LN involvement spreading over the common hepatic artery and celiac axis (area 2). RESULTS: HP-LN involvement was detected in 17 patients. The survival rate was significantly lower in patients with HP-LN involvement. HP-LN involvement was the most significant prognostic factor. Survival was significantly higher in patients with HP-LN involvement limited to area 1 than in those with HP-LN involvement spreading over area 2. CONCLUSIONS: HP-LN involvement was the most significant prognostic indicator in patients with colorectal liver metastases. Positive LNs of area 1 should no longer be considered an absolute contraindication to liver resection, but in case of area 2 lymph node involvement, liver resection does not seem justified.

Adult↗

Auxiliary partial orthotopic liver transplantation (APOLT) in the treatment of acute liver failure.

BACKGROUND: Auxiliary partial orthotopic liver transplantation (APOLT) has been developed in order to benefit from the efficacy of orthotopic liver transplantation (OLT) in the treatment of fulminant hepatic failure (FHF), but to avoid the negative counterpart of OLT which is to eliminate the possibility of native liver (NL) regeneration and which consequently implies a life-long immunosuppression. METHODS: In our institution we performed 16 consecutive APOLTs in 15 patients between October 1992 and December 1999. Patients' mean age was 30 years (range 0.5-65 years). The causes of FHF were viral (HAV = 3; HBV = 3), drugs (n = 4), or others (n = 5). None of the patients had a history of chronic liver disease. The decision to transplant was taken when the patients met well-defined criteria. All but one of the patients were in a coma. RESULTS: Five patients died, 10 patients are alive (66.7%). Regeneration of the NL occurred in 11 of the 15 patients (73.3%) and in 8 of the 10 survivors. Six of these 8 patients have permanently stopped immunosuppressive therapy. These results can be favorably compared with those of OLT for FHF. In the European Transplant Registry, the survival rate is 57% at 5 years (2612 patients receiving OLT for FHF between 1988 and 1998). In our experience the survival rate is 59% at 5 years (42 patients receiving OLT for FHF between 1987 and 1999). CONCLUSIONS: APOLT is feasible in both adults and children; it rapidly restored liver function and reversed encephalopathy. Right APOLT seems more advisable since the right liver provides more functional hepatocytes; however, left APOLT harvested in an adult appears sufficient for a child. APOLT should be proposed only to patients with high chances of liver regeneration: age of recipient, etiology of liver failure, interval between onset of jaundice and occurrence of encephalopathy, and quality of liver graft are early prognostic indicators. Better results have been observed with younger patients (less than 40 years old) presenting with FHF (rather than subfulminant hepatic failure (SHF)) and due to HAV, HBV, or paracetamol.

Adolescent↗

Failure of liver cirrhosis induction by thioacetamide in Nagase analbuminaemic rats.

Repeated administration of thioacetamide (TA), either intraperitoneally or in drinking water, produced liver cirrhosis in normal Sprague-Dawley rats (SDR) with significant histological alterations similar to those observed in human cirrhosis. In the present study, we evaluated the ability of TA to induce liver cirrhosis in mutant Nagase analbuminaemic SDR. Thioacetamide was administered either intraperitoneally up to 4 months or in drinking water up to 6 months to normal and to Nagase analbuminaemic SDR. Nagase analbuminaemic rats (NAR) were also administered TA in drinking water up to 10 months. Liver cirrhosis development was determined by macroscopic and microscopic analysis. In contrast to normal SDR, no histological characteristics of cirrhosis could be observed in NAR submitted to a 4 or 6 months treatment with TA. Such failure to induce cirrhosis in Nagase rats was confirmed even after prolonged TA administration in drinking water for up to 10 months. In contrast, fibrosis and cholangiolar proliferation occurred in the 10-month TA-treated analbuminaemic rats, suggesting that the mechanisms involved in cirrhosis induction are different from those involved in fibrosis development and carcinogenesis. It is unlikely that the protective effect against TA-induced cirrhosis observed in analbuminaemic rats is related to the absence of albumin in this rat strain, since a co-administration of TA with albumin in analbuminaemic rats did not restore the potential for TA to induce cirrhosis in this rat strain. In conclusion, the fact that induction of cirrhosis by TA is prevented in the inherently hyperlipidaemic and hypercholesterolaemic analbuminaemic rats could be considered for potential application in the treatment of clinical cirrhosis.

Administration, Oral↗

Reduction of blood glucose variability in type 1 diabetic patients treated by pancreatic islet transplantation: interest of continuous glucose monitoring.

OBJECTIVE: To compare the glycemic profiles of patients with type 1 diabetes treated with either an implantable insulin pump or pancreas or islet transplantation by the means of the continuous glucose monitoring system (CGMS; Minimed, Sylmar, CA). RESEARCH DESIGN AND METHODS: The CGMS enabled recording of subcutaneous glucose concentrations (range 2.2-22 mmol/l) over 72 h (288 measurements per day). Over 3 days, 26 patients with type 1 diabetes were connected to a CGMS: 10 patients were treated with intraperitoneal insulin infusion through an implantable pump (IPII), 9 patients were treated with simultaneous pancreas-kidney transplantation (SPK), and 7 patients were treated with pancreatic islet transplantation after kidney grafting (IAK). All SPK patients and four IAK patients were insulin independent, whereas three IAK patients had partial graft function and reduced exogenous insulin needs. Glucose control was evaluated by the mean glucose concentration, glucose variability, and the number and duration of hypoglycemic events (<3.3 mmol/l) over 3 days. RESULTS: The mean glucose concentration and the glucose variability in SPK and IAK patients were significantly lower than those observed in patients treated with IPII: 5.38 +/- 1.12 and 5.83 +/- 0.81 vs. 7.81 +/- 1.55 mmol/l (P < 0.001) and 1.40 +/- 0.42 and 1.32 +/- 0.53 vs. 3.47 +/- 1.66 mmol/l (P < 0.001), respectively. Furthermore, the mean glucose concentration and the glucose variability were comparable between SPK and IAK patients. Over 3 days, no hypoglycemic events were observed in SPK patients and insulin-independent IAK patients. A total of 4.12 +/- 1.66 hypoglycemic events were detected in the IPII patient group, whereas only 0.66 +/- 0.57 events were observed in IAK patients with partial graft function (P < 0.001). The duration of the hypoglycemic events was significantly longer in IPII patients as compared with IAK patients: 64 +/- 33 vs. 30 +/- 15 min for the day period and 130 +/- 62 vs. 30 +/- 27 min for the night period (P < 0.001). CONCLUSIONS: Use of subcutaneous CGMS confirms that islet transplantation can be as efficient as pancreas transplantation in restoring good metabolic control and reducing blood glucose variability. Metabolic improvement due to use of an implantable insulin pump requires insulin delivery by a closed loop.

Adult↗

Auxiliary liver transplantation and bioartificial bridging procedures in treatment of acute liver failure.

The aim of this review is to discuss the place of auxiliary liver transplantation (ALT) and other cellular based bridging procedures such as hepatocyte transplantation, ex vivo liver perfusion, and bioartificial livers, in the treatment of acute liver failure, vis à vis conventional orthotopic liver transplantation. Hepacocyte transplantation, and ex vivo pig or human liver perfusion are still experimental procedures. Bioartificial livers using human tumoral hepatocytes or porcine hepatocytes have been used in clinical situations as a bridge to transplantation, i.e. to gain the time required to find a high-quality graft for conventional or auxiliary liver transplantation. None of these techniques have yet proved capable of keeping a patient alive long enough for the native liver to recover. Conversely, ALT has been shown to be effective in the treatment of acute liver failure and now appears to be a satisfactory bridging procedure pending native liver (NL) regeneration. We report personal experience of 18 ALT procedures performed in 17 patients between October 1992 and December 1999. The ALT procedure was indicated when patients met criteria for conventional transplantation; it was ultimately selected when a fresh frozen biopsy of the NL did no show any fibrosis. Six patients died within the first 2 postoperative months. The remaining 11 patients are alive, with a follow-up ranging from 2 to 7 years. Regeneration of the NL occurred in 11 of the 17 patients (65%) and in 8 of the 11 survivors (72%), 6 of whom have permanently stopped immunosuppressive therapy. We conclude that liver failure should no longer be handled outside centers where all types of transplantation can be offered, and where innovative therapies such as hepatocyte transplantation and extracorporeal liver-assist devices are being developed and evaluated.

Adolescent↗