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Biomedical subjects

M Knoop

Publications and source records attributed to M Knoop.

At least 37 records · Page 2Linked to original sources
PubMed1998

A liver with polycystic liver disease as graft for orthotopic liver transplantation.

Donor organ shortage calls for widening of criteria for organ transplantation. In exceptional cases, even livers with macroscopic alterations may be accepted for transplantation. The case of a patient who received a liver graft from a donor with previously unknown adult polycystic degeneration is reported. The liver showed only small bilobar cysts with less than 10% of hepatic replacement and was successfully used for orthotopic liver transplantation. Two years after transplantation the patient is in good clinical condition and has returned to work.

Cysts↗
PubMed1998

A randomized, placebo-controlled trial with anti-interleukin-2 receptor antibody for immunosuppressive induction therapy after liver transplantation.

The introduction of quadruple induction therapy after liver transplantation with the murine anti-interleukin-2 receptor (IL-2R) antibody (BT563) has decreased the incidence of serious side effects, such as tachycardia, hypertension, rash, fever and nausea since it does not lyse its target cell. To investigate the immunosuppressive efficacy of BT563, a placebo-controlled trial was performed and BT563 was added to the standard triple induction after liver transplantation. Forty consecutive recipients of primary orthotopic liver transplants (OLT) (median age 47 yr [range 18-65]) were randomized. All patients received triple immunosuppression with cyclosporine A (CyA), prednisolone (PRED) and azathioprine (AZA). In addition, 19 patients received BT563 (Biotest, Dreieich, Germany) at a dose of 10 mg/d from day 0 until day 12. The remaining 21 patients received a placebo infusion at the same days after transplantation. Minimal follow-up for all patients was 3 yr. Patient survival at 3 yr was 74% in the BT563 group and 90% in placebo group. Similar results were observed for graft survival. Two acute rejection episodes were detected in the BT563 group and 9 acute rejections (5 steroid-resistant) were observed in the placebo group (p < 0.034). The incidences of sepsis, pneumonia, cholangitis, urinary tract infections as well as cytomegalo-virus (CMV) infections were similar in both groups. Side effects of the BT563 therapy and/or post-transplant lymphoproliferative disease (PTLD) were not detected. Quadruple induction therapy with BT563 significantly reduces the incidence of rejection episodes after liver transplantation, while infectious complications and/or PTLD is not increased. Therefore, the anti-IL2 receptor antibody BT563 constitutes a safe and efficient addition to the immunosuppressive induction regimen following OLT.

Acute Disease↗
PubMed1998

[Surgical interventional endoscopic treatment concept of bile duct lesions after laparoscopic cholecystectomy].

In this study we analysed 25 patients with bile duct injuries following laparoscopic cholecystectomy retrospectively. Reconstructive surgery was necessary in 24 patients with bile duct lesions that could not be treated endoscopically. After a mean follow-up of 28 months (3-65) we have good functional outcome in the majority of patients, however, one patient required liver transplantation because of secondary biliary cirrhosis.

Bile Ducts↗
PubMed1997

A prospective randomized trial comparing interleukin-2 receptor antibody versus antithymocyte globulin as part of a quadruple immunosuppressive induction therapy following orthotopic liver transplantation.

BACKGROUND: Quadruple immunosuppressive induction therapy has been shown to markedly reduce the incidence of acute rejection episodes without increasing the incidence of infectious complications after liver transplantation. However, the use of polyclonal antibody preparations (e.g. antithymocyte globulin [ATG]) is associated with side effects such as fever and tachycardia. To evaluate the efficacy and the safety of a monoclonal antibody directed against the interleukin-2 receptor (BT563) in comparison with ATG as part of a quadruple induction regimen, a prospective, randomized study was conducted. METHODS: Eighty consecutive adult recipients of primary orthotopic liver transplants were randomized to receive either BT563 (10 mg/day; days 0-12; n=39) or ATG (5 mg/kg/day; days 0-6; n=41) in addition to the standard immunosuppressive protocol consisting of cyclosporine, and prednisolone, and azathioprine. RESULTS: Patients treated with BT563 had a significantly lower incidence of steroid-sensitive rejection episodes (3 vs. 11; P<0.025) and also significantly fewer drug-related side effects (4 vs. 18, P<0.038) when compared with patients treated with ATG. The incidence of infectious complications was not different between the two groups. Patient survival did not differ significantly between the two groups (84.6% at 1, 2, and 3 years in the BT563 group and 90.2% at 1 year and 87.8% at 2 and 3 years for the ATG group). Analysis of graft function showed an advantage for the BT563 group in terms of postoperative bilirubin levels. However, no differences were observed in long-term follow-up between the two groups. CONCLUSIONS: Our results indicate that treatment with anti-interleukin-2 receptor antibody as part of quadruple induction therapy after orthotopic liver transplantation is safe and effective and shows fewer steroid-sensitive rejection episodes as well as fewer side effects when compared with quadruple induction therapy including ATG.

Adult↗
PubMed1997

Mycophenolate mofetil added to immunosuppression after liver transplantation--first results.

Mycophenolate mofetil (MMF) has been used successfully as an immunosuppressive agent after kidney and heart transplantation, but experience with MMF after liver transplantation is still limited. Between August 1995 and January 1996, we treated 20 patients with MMF after orthotopic liver transplantation in an open, prospective study. Five out of eight patients with acute rejection and one patient with early chronic rejection showed a complete response after MMF was added to the immunosuppression. Three patients with chronic rejection did not improve, one died, and two have stable graft function at present. In eight patients who suffered from toxicity, a reduction in the dosage of tacrolimus was attempted with simultaneous MMF therapy. One patient died due to multiple organ failure. Liver function improved completely in one other patient, and partially in three patients after adding MMF. In the remaining three patients, a reduced dosage of tacrolimus or cyclosporin, together with MMF, reduced toxicity, not significantly. In conclusion, MMF appears to be a safe and potentially useful adjuvant immunosuppressive agent for rescue and maintenance therapy.

Acute Disease↗
PubMed1997

Prophylactic use of low-dose urodilatin for prevention of renal impairment following liver transplantation: a randomized placebo-controlled study.

Many therapeutic measures have been employed to prevent or at least ameliorate postoperative renal impairment following liver transplantation. Recent clinical phase II studies have demonstrated that the new natriuretic peptide urodilatin has beneficial effects on renal function following heart and liver transplantation. The present study reports the first prospective randomized placebo-controlled trial of prophylactic urodilatin administration following liver transplantation. Seventy consecutive recipients of primary liver transplants were included in the study following randomization, and 33 patients continuously received urodilatin at a dose of 20 ng/kg/min for 7 d. The remaining 37 patients received a placebo infusion for the same time period. The course of serum creatinine and urea did not differ between the two groups nor did the daily urine production. However, the urodilatin group showed a higher preoperative median serum creatinine and a significant reduction on days 1 and 2, whereas this observation was not made in the placebo group. Furthermore, less furosemide was administered to the patients in the urodilatin group during the first 2 d. The incidence of postoperative hemodialysis and the number of treatments did not differ between the groups either (urodilatin group 4, vs. placebo group 6 and 22 for both groups, respectively). Side effects of the urodilatin therapy were not detected. The prophylactic low-dose urodilatin administration resulted in a trend towards amelioration of the renal function, but did not result in significant differences between the two experimental groups. Further studies, using higher doses, will be required to define the value of urodilatin for prevention of renal impairment after liver transplantation.

Adolescent↗
PubMed1996

Viral dynamics of hepatitis C early after orthotopic liver transplantation: evidence for rapid turnover of serum virions.

The pathogenesis of hepatitis C virus (HCV) infection is likely to be associated with viral replication in vivo, but little is known concerning the dynamics of HCV turnover. We performed serial measurements of serum HCV-RNA levels following orthotopic liver transplantation (OLT) in nine patients with HCV-positive cirrhosis. Serum HCV-RNA levels were determined by quantitative polymerase chain reaction before, immediately after, and for up to 1 month after OLT. There was a rapid decline in HCV-RNA levels from 3.1 +/- 1.3 x 10(5) copies/ mL (mean +/- SEM) preoperatively to 0.15 +/- 0.6 x 10(5) copies/mL on the first and 0.16 +/- 0.6 x 10(5) copies/mL on the second postoperative day (mean viral half-life, 4.0 +/- 0.5 h). Thereafter, HCV-RNA levels increased in all but one patient, and by postoperative day 8 reached 3.6 +/- 1.3 x 10(5) copies/mL, exceeding the preoperative levels irrespective of the use or not of rescue immunosuppressive therapy including steroid bolus administration. In most patients, serum virions continued to increase averaging 11.6 +/- 2.8 x 10(5) copies/mL on the 30th postoperative day. These findings indicate that the half-life of HCV is quite short, and that extrahepatic viral replication contributes little to the total virus pool in serum. Furthermore, the marked HCV replication beginning as early as the third postoperative day strongly suggests that the liver graft is rapidly reinfected by HCV after OLT.

Adult↗
PubMed1996

Surgical concepts for therapy of pancreatic neoplasms.

Surgical treatment of pancreatic malignomas has improved dramatically over the past decades, which is illustrated by the decrease in perioperative mortality to 1%-2%. This has made it possible to widen the indication for pancreatic resection and the extent of the surgical intervention. Experience with pancreatic resection for neoplasms at our center using standard surgical techniques during the last decade is reviewed, with special focus on the cases with partial resection of the portal vein. Perioperative morbidity has decreased below 5% and 5-year survival rates reach 60% for stage I tumors and 15%-25% for stage II and III tumors. The authors conclude that surgical therapy for pancreatic neoplasms is safe and yields a considerably higher quality of life for the patient and therefore should be considered in all patients with this disease entity.

Adult↗
PubMed1996

Clinical significance of recurrent primary biliary cirrhosis after liver transplantation.

Primary biliary cirrhosis (PBC) represents a classic indication for orthotopic liver transplantation (OLT); as an autoimmune disease, however, the existence and incidence of recurrent PBC is a matter of significant controversy. Between September 1988 and September 1994 a total of 544 OLTs was performed at our institution. Forty-nine patients (40 female) with a median age of 50.5 years and previous surgery in 36.4%, received a liver graft for PBC. The mean serum bilirubin level was 8.9 mg/dl (range 0.7-29.7). Immunosuppression was commenced as a cyclosporine A-based quadruple therapy or with FK 506 and prednisolone. Protocol liver biopsies were taken at defined intervals posttransplant. Two patients died due to Legionella pneumonia and hypoxic brain damage 2 and 8 weeks after OLT, resulting in an actuarial 5-year survival rate of 95% with 47/49 patients being alive compared to 83.5% of all other liver recipients. Evidence of recurrence of PBC, as defined by elevated cholestatic parameters and histological features of PBC, was found in four patients, another five patients showed only histological signs. Recurrence of PBC, which might compromise the long-term outcome after OLT, was suspected in 4/47 patients (8.5%). This evidence of recurrent PBC is in conflict with findings of other groups that did not report recurrent PBC. OLT is still the optimal therapy for advanced PBC, with an excellent prognosis.

Female↗
PubMed1996

The importance of late infections for the long-term outcome after liver transplantation.

We investigated the late infections of 400 consecutive liver transplantations performed in 368 patients. After a mean follow-up of 45 months, a total of 180 late infections occurred in 110 liver recipients. Frequent agents were CMV, enterococcus, candida and staphylococcus. Pneumonia was the most dangerous late infection with a high mortality rate. Late infections were responsible for ten deaths that were all caused by atypical pneumonia. The majority of late infections appeared during the first year after liver transplantation. Thereafter, the risk of infection declined significantly.

Humans↗
PubMed1995

Comparison of FK506- and cyclosporine-based immunosuppression in primary orthotopic liver transplantation. A single center experience.

FK506 has been proven effective for prevention and treatment of liver allograft rejection. Herein, we compare FK506-based immunosuppression with an effective quadruple immunosuppressive regimen, including cyclosporine and antithymocyte globulin. The results of a single center participating in the European multicenter FK506 study are reported, including immunosuppressive efficacy as well as toxicity. One-year patient and graft survival was 96.7% and 90.0% for the CsA group and 90.2% and 88.5% for the FK506 group, which is not statistically different. The incidence and severity of acute rejection episodes during the first postoperative year was similar in both treatment groups with 34.4% and 33.3% for the FK506 and CsA treatment group, respectively. Immunosuppressive potency was better for the FK506 group compared with the CsA group according to the incidence of chronic rejection. Furthermore, 5 patients (8.3%) required conversion to FK506 for immunological reasons, i.e., refractory acute or chronic rejection. The incidence of moderate and severe neurotoxicity during the early postoperative period was higher in the FK506 group (21.3%) compared with the CsA group (11.7%), while the incidence of renal insufficiency and acute renal failure was similar (18.0% and 18.3% for the FK506 and CsA treatment groups, respectively). The incidence of CMV infection was significantly higher under treatment with CsA (25.0%) than with FK506 (6.6%) (P < or = 0.05), while the incidence of pneumonia (13.1% and 13.3%), cholangitis (29.5% and 26.7%), and urinary tract infection (39.3% and 28.3% for the FK506 and CsA treatment groups, respectively) was similar in both treatment groups. However, infection was more serious in some cases treated with FK506, and evolved as the main cause of death in the FK506 treatment group. Therefore, caution should be paid to over immunosuppression and toxicity in FK506-treated patients. Regarding the monitoring of FK506, FK506 plasma level failed to be a reliable indicator, and therefore we recommend measurement of whole blood FK506 levels. Our data indicate that immunosuppressive potency of FK506 is greater than that of CsA, especially concerning the incidence of chronic rejection.

Adolescent↗
PubMed1995

[Immunologic tolerance after experimental liver transplantation].

Allografts in the rat liver are rejected less vigorously than other primarily vascularized allografts; they show a better survival rate and induce donor-specific unresponsiveness or tolerance in some donor-recipient combinations. This overview focuses on the immunologic mechanisms of this privileged status of liver allografts. A variety of possible mechanisms, such as generation of suppressor T-cells, humoral factors and microchimerism, has been related to the observed hyporeactivity. A further analysis of these phenomena may enhance the development of clinical organ transplantation protocols that allow for establishment of donor-specific unresponsiveness without the need for life-long immunosuppression.

Animals↗