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A R Mueller

Publications and source records attributed to A R Mueller.

At least 19 recordsLinked to original sources
PubMed2005

IL-2 antagonists: the European perspective.

Acute rejection remains the main risk factor following intestinal transplantation. New immunosuppressive agents have substantially reduced the incidence of severe acute rejection. The question arises, which is the most powerful immunosuppressive combination with the lowest incidence of side effects? According to International Intestinal Transplant Registry data, anti-IL-2 antibodies are slightly advantageous compared with antilymphocyte preparations with respect to long-term patient survival. However, different antilymphocyte preparations are used in different doses and at different time points. The anti-IL-2 antibodies daclizumab and basiliximab were also used in different protocols. Therefore, final results on efficacy are awaited. The most important difference between IL-2 antibodies and antilymphocyte preparations is the suppression of CD4+ CD25+ T lymphocytes by anti-IL-2 antibodies. Antilymphocyte preparations do not affect CD4+ CD25+ T cells. Because regulatory CD4+ CD25+ T cells are essential for tolerance induction, protocols attempting tolerance may omit anti-IL-2 antibodies in the future.

Antilymphocyte Serum↗
PubMed2004

Immunosuppression following intestinal transplantation.

Acute rejection is still the main risk factor following intestinal transplantation. Potent immunosuppression decreases rejection frequency, but may increase immunosuppression-related complications. Isolated small intestinal transplantation was performed in 14 adult patients with short bowel syndromes. Immunosuppression included tacrolimus and rapamycin in combination with steroids for 6 months after ATG or daclizumab induction therapy. In addition to protocol biopsies, cellular immune status and soluble immune parameters were used to guide immunosuppression. CMV and EBV markers were determined on a routine basis. Ten of 14 patients (71%) survived for 1 to 38 months (median 26 months). Eight patients are at home, in good physical condition, completely on enteral nutrition. Among the 5 patients (36%) who developed acute rejection, 2 patients with early postoperative events underwent graft removal and 1 patient died due to multiple organ failure. Two patients developed severe acute rejection episodes at 10 and 24 months following transplantation. Both patients recovered following OKT3 rescue therapy and increased baseline immunosuppression with repeated methylprednisolone and infliximab treatment. Infections included peritonitis (n = 3), pneumonia (n = 3), central line infection (n = 5), urinary tract (n = 2), CMV (n = 2), and EBV (n = 4). Two patients developed anastomotic leaks at the esophageal and coloanal anastomosis. In conclusion, acute rejection episodes can be controlled by potent immunosuppression using tacrolimus in combination with rapamycin. Immunosuppression-associated complications, including infections, were in an acceptable range. However, even late after transplantation, reduction in immunosuppression may lead to severe rejection without major clinical symptoms.

Adult↗
PubMed2004

Isolated adult intestinal transplantation using portal venous drainage.

There is some evidence that portal venous drainage may offer immunologic and metabolic advantages in small bowel transplantation. Isolated small bowel transplantation was performed in 14 adult patients. In all cases, the donor pancreas was transplanted into another patient. During the donor procedure, the superior mesenteric artery and vein were separated below the division of the inferior pancreaticoduodenal artery and below the veins of the pancreatic head. An arterial interposition graft was used in all cases. One donor mesenteric artery was reconstructed in 6 patients; two arteries in 5 patients; and three arteries in 3 patients. Proximal arteries of the graft were ligated and the upper part of the jejunum resected. In 10 patients, a direct anastomosis was performed in an end-to side fashion between donor superior mesenteric vein (SMV) and recipient inferior mesenteric vein (IMV). In 2 patients, a branch of the superior mesenteric vein was used and 2 patients required a venous interposition graft to confluence using the donor iliac vein. Patency of the venous anastomosis was documented by magnetic resonance imaging (MRI) angiography after 6 months. No vascular complications have been observed to date. Portal venous drainage is technically feasible in most cases. An anastomosis to the recipient IMV offers the advantage of being direct despite the short donor vein segment. Furthermore, donor and recipient vessels are well matched for size. Using microsurgical techniques, vascular complications may be avoided.

Adult↗
PubMed2004

Management of venous access problems before and after intestinal transplantation: case reports.

Patients suffering irreversible loss of intestinal function require total parenteral nutrition (TPN). During long-term TPN, catheter infections are a common problem and intestinal transplantation (ITx) is indicated when patients experience loss of venous access. We report two patients with short bowel syndrome--one before and one after ITx. The patient listed for ITx had several catheter infections with septic temperatures. Staphylococcus aureus, detected in blood cultures, was treated with vancomycin. Packing of the central venous line (CVL) with vancomycin was not successful; the CVL was changed. Search for an infectious focus identified a septic femoral head destruction that was treated by incision and implantation of a hip endoprothesis. Thereafter, the patient was free from infection. The second patient underwent ITx on January 2, 2003, and is free from TPN. ITx was complicated by temporary acute renal failure and heparin-induced thrombocytopenia (HIT) syndrome. After compensation of kidney function, the patient required additional saline solution (1 to 2 L/d) to optimize renal perfusion. A CVL was placed in the external iliac vein (EIV) due to previous loss of venous access. At 2 months after ITx, the CVL was infected and the patient was septic. MR scan revealed only one jugular vein to provide vascular access. Therefore, the CVL was changed from the right to the left EIV. Postoperatively, the patient developed thrombosis of right iliac vein and a wound infection that is probably related to the nearby graft ileostomy. At present, the patient is in good condition with a functioning graft. In conclusion, recurrent CVL infections before ITx might reflect other infectious foci that require intensive diagnostic evaluation. After ITx, CVL infection may cause venous thrombosis. Therefore, a single upper venous access should be preserved for optimal care.

Adult↗
PubMed2000

Liver transplantation for alcoholic cirrhosis.

Because of the donor shortage, there are concerns for liver transplantation in patients with alcoholic cirrhosis. We therefore analyzed patients transplanted for alcoholic cirrhosis at our center with respect to patient and graft survival, recurrence of disease, and postoperative complications. Out of 1000 liver transplantations performed in 911 patients, 167 patients were transplanted for alcoholic cirrhosis; 91 patients received CsA- and 76 patients FK506-based immunosuppression. Recurrence was diagnosed by patient's or relative's declaration, blood alcohol determination, and delirium. Diagnosis and treatment of acute and chronic rejection was performed as previously described. One- (96.8% versus 91.3%) and 9-year patient survival (83.3% versus 80%) compared well with other indications. Five of 15 patients died due to disease recurrence. Recurrence of disease was significantly related to the duration of alcohol abstinence prior to transplantation. In patients who were abstinent for less than 6 months (17.1%), recurrence rate was 65%, including four of the five patients who died of recurrence. Recurrence rate decreased to 11.8%, when abstinence time was 6-12 months and to 5.5%, when the abstinence times was > 2 years. Next to duration of abstinence, alcohol relapse was significantly related to sex, social environment, and psychological stability. The incidence of acute rejection compared well with other indications (38.1%); CsA: 40.1% versus 33.3% in FK506 patients. In all, 18.2% of CsA patients experienced steroid-resistant rejection compared with 2.6% of FK506 patients. Seven patients (7.6%) in the CsA group and one patient (1.3%) in the FK506 group developed chronic rejection. A total of 57.1% developed infections; 5.7% were life-threatening. CMV infections were observed in 14.3% (versus 25% for other indications). New onset of insulin-dependent diabetes was observed in 8.6% and hypertension in 32.4%. In conclusion, alcoholic cirrhosis is a good indication for liver transplantation with respect to graft and patient survival and development of postoperative complications. FK506 therapy was favourable to CsA treatment. Patient selection is a major issue and established criteria should be strictly adhered to. Patients with alcohol abstinence times shorter than 6 months should be excluded, since recurrence and death due to recurrence was markedly increased in this group of patients.

Adult↗
PubMed2000

Perioperative factors influencing patient outcome after liver transplantation.

We have previously shown that the development of multiple organ dysfunction syndrome (MODS) after liver transplantation significantly reduced patient survival. Therefore, the question arises of which are the most prominent perioperative donor and recipient factors leading to MODS after transplantation. In total, 634 patients with 700 liver transplants were analyzed. Donor factors included age, increase in transaminases, sex mismatch, requirement for catecholamines, intensive care time, histology, and macroscopic graft appearance. Recipient factors included Child classification, preoperative gastrointestinal (GI) bleeding, mechanical ventilation, hemodialysis, and requirement for catecholamines. MODS was defined by more than two severe organ dysfunctions. The cumulative 2 to 9-year patient survival was 90.9% in patients developing less than 3 severe organ dysfunctions following transplantation. Survival decreased to 60.3% in patients with MODS. Neither any of the donor factors nor the duration of cold ischemia (CIT) was associated with an increase in MODS or decrease in survival. On the other hand, duration of warm ischemia, amount of blood loss, requirement for red packed blood cells, and reoperation had an influence on the development of MODS (40%-56%) and decreased patient survival to 58%-69%. Preoperative therapy with catecholamines, GI bleeding, mechanical ventilation, and hemodialysis were associated with the development of MODS in 54%-88%. Patient survival following MODS decreased to 50%-74%. Initial graft function had a slight influence on the development of MODS, but no influence on the long-term patient survival. In conclusion, patient survival was significantly influenced by the development of postoperative MODS. The most prominent factors in this were recipient and intraoperative ones. No major influence was observed for donor factors, CIT, and initial graft function. Prevention of MODS will further improve the outcome after liver transplantation.

Age Factors↗
PubMed1998

The extracellular matrix: an early target of preservation/reperfusion injury and acute rejection after small bowel transplantation.

BACKGROUND: Endothelial cells are known to be an early target of preservation/reperfusion injury and acute rejection, whereas the extracellular matrix (ECM) may also play an equally important role in the sequelae of both events. METHODS: Syngeneic and allogeneic rat small bowel transplantations (SBTX) were performed after 6 hr of preservation. Animals were subsequently killed at defined time points for determination of ECM parameters within the graft and in plasma. RESULTS: Laminin levels were significantly increased 20 min after reperfusion (syngeneic SBTX: 357+/-65.9 ng/ml; allogeneic SBTX: 361+/-79.6 ng/ml; P< or =0.01). After syngeneic transplantation, laminin levels normalized by postoperative day (POD) 7, whereas there was a rejection-induced increase after allogeneic SBTX (POD 7: 179+/-60.1 ng/ml; POD 9: 333+/-13.6 ng/ml; P< or =0.01 vs. syngeneic SBTX). This increase was accompanied by an increase in tumor necrosis factor-alpha levels at POD 9. Hyaluronic acid levels were significantly elevated after 24 hr (syngeneic SBTX: 1086+/-176 microg/L; allogeneic SBTX: 918+/-108 microg/L; P< or =0.01). After syngeneic SBTX, hyaluronic acid levels normalized by POD 7, whereas persistently higher levels were observed after allogeneic SBTX. Immunohistochemistry confirmed early changes (20 min after reperfusion) at the ECM. Anti-laminin and anti-CD44 staining normalized at POD 5 after syngeneic SBTX. After allogeneic SBTX, rejection-specific changes were evident with anti-laminin staining commencing on POD 5 and progressing until POD 9. At similar time points, increased expression of fibronectin- and interferon-gamma-positive material was evident. CONCLUSIONS: The ECM can be considered to be an early target of preservation/reperfusion injury and acute rejection. Plasma parameters reliably reflected the changes observed within the graft. Laminin and hyaluronic acid levels may be used as indicators of initial graft function. Furthermore, the increase in laminin levels was an early indicator of acute rejection. Determination of these parameters may significantly improve monitoring after SBTX.

Animals↗
PubMed1998

Searching for the optimal management of hepatitis C patients after liver transplantation.

The optimal immunosuppressive regimen in patients transplanted for hepatitis C (HCV) is still under discussion. High immunosuppression may promote viral replication and recurrent graft hepatitis. But acute and chronic rejection frequently seen in conjunction with HCV recurrence may require some rescue therapy. One hundred and thirty-seven patients transplanted for HCV cirrhosis, who were HCV-RNA positive prior to transplantation, were analyzed. Seventy-nine patients received CSA-based immunosuppression and 58 patients FK506-based immunosuppression. One-month patient survival was 100% in both groups. Three month and 1-year survival rates and the cumulative 1-5-year patient survival was similar in CsA-treated [67/79 (84.8%)] and FK506-treated patients [50/58 (86.2%)]. Retransplantations for HCV recurrence were performed in 5.1% of CsA-treated patients and 6.9% of FK506-treated patients; it was successful in 50% and 75% of patients, respectively. Conversion from CsA to FK506 and vice versa was high with 25 out of 79 patients (31.6%) converting in the CsA group and 8 out of 58 patients (13.8%) converting in the FK506 group. Conversion to FK506 was performed due to acute and chronic rejection and to CsA because of toxicity and HCV recurrence. In both groups, 25% of converted patients died. Five patients of the CsA group and 9 of the FK506 group received OKT3; more than one-third of each group died. Five patients in the CsA group and 6 in the FK506 group received mycophenolate mofetil (MMF) for HCV recurrence or acute and chronic rejection in conjunction with HCV recurrence. All patients of this critical group are alive with good graft function. In conclusion, survival rates of HCV patients were similar to those seen for other indications. Conversion from CsA to FK506 and vice versa was high and reflects a critical group concerning patient survival. OKT3 treatment should be avoided. A promising therapeutic option for critical patients experiencing acute or chronic rejection in conjunction with HCV recurrence may be treatment with MMF.

Hepatitis C↗