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Biomedical subjects

H Tilg

Publications and source records attributed to H Tilg.

At least 91 records · Page 5Linked to original sources

Urinary and pancreatic juice neopterin excretion after combined pancreas-kidney transplantation.

The aim of this study was to investigate excretion of urinary and pancreatic juice neopterin in patients after combined pancreas-kidney transplantation and to relate it to the clinical course. The study design was a prospective observation study. Thirty consecutive patients with end-stage diabetic disease received a simultaneous pancreas-kidney transplant with pancreaticocystostomy and temporary exteriorization of pancreatic juice. In 30 patients urinary neopterin (UN) was measured daily from day +1 until hospital discharge by high-performance liquid chromatography; in ten of these 30 patients pancreatic juice neopterin (PJN) was additionally analyzed daily from day +1 for as long as pancreatic juice was diverted to the exterior. Elevated urinary neopterin levels were observed in acute cellular rejection (19/24 rejection episodes) and in bacterial infection (9/16 cases)--however, increments were more pronounced in acute cellular rejection. In contrast, pancreatic juice neopterin increased in all seven observed pancreatic graft rejection episodes. Pancreatic juice infection did not result in a rise in pancreatic juice neopterin excretion. Patients without postoperative complications exhibited stable and low urinary/pancreatic juice neopterin levels. The highest urinary neopterin levels were observed in CMV disease. Levels measured prior to discharge from hospital did not correlate with graft and patient survival. Evaluation of urinary and pancreatic juice neopterin, although nonspecific, helps identify patients with an uncomplicated or complicated clinical course. Pancreatic juice neopterin appears to be superior to urinary neopterin in early detection of pancreatic graft rejection. This may be of particular importance in monitoring nonuremic pancreas allograft recipients.

Adult↗

Circulating serum levels of interleukin 6 and C-reactive protein after liver transplantation.

The study objectives were to investigate serum levels of interleukin-6 and C-reactive protein (CRP) after liver transplantation to correlated measurements with various clinical parameters. Twenty-three patients were studied after orthotopic liver transplantation. Serum IL-6 activity was evaluated by testing its capacity to induce proliferation of the IL-6-dependent hybridoma cell line B9. CRP was assessed by a nephelometric method. Only two of seven patients with acute cellular rejection developed an increase of serum IL-6 and CRP. In contrast to this rejection group, elevated IL-6 levels were observed in 7/9 patients with bacterial infections. Peak values for IL-6 were observed one day and for CRP two days after clinical diagnosis of infection. CMV disease was also associated with markedly increased IL-6 and CRP levels in 5/7 patients. Surprisingly, levels in this condition were approximately in the same range as in bacterial infection. IL-6 and CRP serum levels seen in bacterial infection and CMV disease were significantly higher than those in rejection (P less than 0.001). Serum IL-6 activity was neutralized by an antiserum directed against recombinant human IL-6. Preferential elevations of IL-6 and CRP represent one feature of bacterial and viral infections. Elevation of TNF during rejection as described earlier is only rarely accompanied by increased serum IL-6 levels.

Bacterial Infections↗

Suppression of thyroid function by interferon-alpha 2 in man.

Profound biological changes occur in patients treated with interferon. Observations of endocrine changes prompted us to examine the effects of subcutaneous alpha-interferon administration in single doses on circulating levels of thyroid stimulating hormone, total thyroxine, and total triiodothyronine in 10 volunteers (5 healthy subjects and 5 patients with hepatitis C). Blood samples were taken on an out-patient basis immediately before and 2, 12, 24, 48, and 72 h after administration of 1, 3, or 5 x 10(6) units of recombinant alpha-interferon. Application of the different dose levels was randomly assigned. Plasma samples were stored at -80 degrees C; after collection of samples had been completed hormone levels were measured using commercially available test kits. At all time points before and after injection of alpha-interferon, standard deviations of measured hormone levels of healthy control subjects and patients overlapped to a considerable extent. At a dose level of 5 x 10(6) units, alpha-interferon significantly increased cortisol levels as described, and decreased the level of thyroid stimulating hormone in the group receiving alpha-interferon as compared to placebo-treated healthy volunteers. The effects occurred 12 h after injection. Maximum suppression of thyroid stimulating hormone levels was observed 24 h after injection, when serum levels of thyroxine and triiodothyronine also were significantly reduced. We conclude that subcutaneous alpha-interferon treatment with doses as low as 5 x 10(6) units affects the control of thyroid function.

Adult↗

Acute hematologic effects of interferon alpha, interferon gamma, tumor necrosis factor alpha and interleukin 2.

This study was designed to investigate acute effects of various doses of the cytokines IFN-alpha, IFN-gamma, Interleukin 2 and tumor necrosis factor alpha on white blood cell differential counts. Before initiation of phase II trials, a dose-determination phase was performed, where three different dose levels of each cytokine were applied as a single dose. White blood cell differential counts were assessed immediately before and 2, 12, 24, 48 and 168 h after injection. Patients enrolled suffered from metastatic cancer or chronic active hepatitis. In addition, IFN-alpha was administered to five healthy volunteers. Results indicate that cytokines cause rapid and transient changes in the numbers of leukocyte subsets. Hematologic changes were cell-type- and cytokine-specific: transient lymphopenia was observed after administration of all four cytokines, reaching a nadir 12 to 24 h after subcutaneous injection. Administration of TNF-alpha and IFN-gamma also caused transient monocytopenia. Neutrophilia developed after administration of Interleukin 2, IFN-alpha and TNF-alpha. We conclude that cytokines play a key role in the regulation of peripheral blood cell traffic by their capacity to influence homing patterns of peripheral blood leukocytes.

Female↗

Recombinant tumour necrosis factor alpha administered subcutaneously or intramuscularly for treatment of advanced malignant disease: a phase I trial.

The pharmacokinetics, toxicity and biological effects of subcutaneous and intramuscular treatment of cancer patients with recombinant tumour necrosis factor alpha (rTNF-alpha) was investigated. 17 patients suffering from refractory malignant disease were treated with either 1.0 micrograms/m2, 10 micrograms/m2 or 100 micrograms/m2 rTNF-alpha. Vital signs, peripheral blood cell counts, TNF and interferon (IFN) gamma serum levels, neopterin, beta 2-microglobulin, C reactive protein (CRP) and cortisol levels were measured immediately before and 2, 12, 24, 48 and 168 h after the first administration of rTNF-alpha. Tumour response was evaluated after 4 and 12 weeks of treatment. The pharmacokinetics followed the same characteristics as those reported for other cytokines. Major toxicities were dose dependent and comprised fever, constitutional symptoms and hypotension. TNF dependent changes were observed in serum levels of IFN-alpha, CRP, neopterin, beta 2-microglobulin, cortisol and white blood cell counts. No objective tumour response was observed. This study indicated that rTNF-alpha administered subcutaneously or intramuscularly results in measurable TNF serum levels, significant toxicity and biological response in absence of clinical efficacy in patients with advanced cancer.

Adult↗

Human monoclonal antibodies neutralizing cytomegalovirus (CMV) for prophylaxis of CMV disease: report of a phase I trial in bone marrow transplant recipients.

The safety and pharmacokinetics of the two neutralizing human IgG1 monoclonal antibodies to cytomegalovirus (CMV) SDZ 89-104 and 89-109 in bone marrow transplant (BMT) recipients was assessed in an open phase I trial. Thirteen patients, 8 seropositive and 5 seronegative for CMV, were treated with allogeneic or autologous bone marrow transplantation. SDZ 89-104 was given to 5 and SDZ 89-109 to 8 patients. Patients were divided into high- and low-dose groups. A fixed prestudy dose of 0.1 mg/kg was given 4 days before BMT. On days 3, 17, 31, 45, 59, and 73, patients were treated with either 0.5 or 2 mg/kg of the respective antibody. Results indicate that doses of 2 mg/kg of SDZ 89-104 or SDZ 89-109 in alternating weeks can be safely administered to BMT patients. Serum trough levels measured by antiidiotype ELISA were approximately 10 micrograms/ml after administration of 0.5 mg/kg and approximately 50 micrograms/ml after treatment with 2 mg/kg of SDZ 89-104 or SDZ 89-109. High serum levels defined by antiidiotype ELISA techniques closely paralleled increased neutralizing activity. Serum half-lives calculated from these data were approximately 6 days.

Adolescent↗

Enhanced serum levels of soluble HLA class I molecules are induced by treatment with recombinant interferon-gamma (IFN-gamma).

In order to investigate serum levels of soluble HLA class I antigens after single injection of various doses of recombinant IFN-gamma (rIFN-gamma) and to correlate the changes observed to beta-2-microglobulin serum levels, we studied five patients with metastasizing renal cell carcinoma. Each patient received three treatment cycles of 10, 100 and 500 micrograms rIFN-gamma three times at weekly intervals. The treatment cycles were separated by a therapy-free interval of 2 weeks. The order of dose levels was randomly assigned to each patient. Serum levels of soluble HLA class I proteins were measured by an ELISA in samples drawn immediately before and 4, 24, 48, 72 and 168 h after each administration of rIFN-gamma. Beta-2-microglobulin was assessed in parallel using a commercially available radioimmunoassay. Significant induction of soluble HLA class I protein serum levels was observed after treatment with 100 and 500 micrograms rIFN-gamma. The increments peaked after 2-4 days and remained elevated for up to more than 7 days. A significant correlation between increments of soluble HLA class I proteins and beta-2-microglobulin was observed. We conclude that measurement of soluble HLA serum levels is practical for monitoring induction of HLA class I synthesis in patients treated with rIFN-gamma. The correlation observed between induction of beta-2-microglobulin and soluble HLA class I proteins indicates that measurement of beta-2-microglobulin might be sufficient for the biological response monitoring in clinical studies.

Carcinoma, Renal Cell↗

Cachexia and tumour necrosis factor-alpha in cytomegalovirus infection.

Although cachexia is a common feature of cytomegalovirus infection, little is known about its cause. To explore any contributory role that tumour necrosis factor-alpha (TNF) might have the serum concentrations of TNF in eight patients who developed CMV disease after liver transplantation were investigated. All patients exhibited pronounced and long lasting increases in TNF serum concentrations. Increased endogenous TNF concentrations were associated with weight loss and anorexia. In contrast, liver transplant recipients without CMV disease showed no weight loss.

Cachexia↗

Recombinant interferon-alpha-2C in chronic myelogenous leukaemia: relationship of sensitivity of committed haematopoietic precursor cells in vitro (BFU-E, CFU-GM, CFU-Meg) and clinical response.

In an ongoing phase-II trial we aimed to predict clinical responsiveness of Philadelphia chromosome positive (Ph1+) chronic myelogenous leukaemia (CML) to recombinant IFN-alpha-2C (rIFN-alpha-2C) by pretesting in vitro. From five normal controls and 14 CML patients in chronic phase, bone marrow samples were taken before treatment and tested for antiproliferative activity by rIFN-alpha-2C, using a microagar culture system for BFU-E, CFU-GM, and CFU-Meg. Light-density nucleated bone marrow cells were stimulated for BFU-E and CFU-Meg colony formation with Alpha medium containing 20% serum obtained from a patient with severe aplastic anaemia. CFU-GM growth was induced with conditioned medium from the cell line GCT. In normal controls BFU-E, CFU-GM and CFU-Meg colony formation was inhibited by rIFN-alpha-2C in a dose-dependent manner. BFU-E proved to be the most sensitive cell lineage (IC50: 65; range: 53-116 U/ml) whereas CFU-GM was about 20 times less sensitive (IC50: 643; range: 480-897 U/ml). The sensitivity of CFU-Meg ranged between these two colony types with 50% growth inhibition at an IFN concentration of 160 (range: 68-246 U/ml). A heterogeneous response to rIFN-alpha-2C in vitro was seen in CML patients. Three of the 14 patients were 'resistant' to rIFN-alpha-2C in vitro with IC50 values for BFU-E, CFU-GM and/or CFU-Meg colony formation greater than 10(4) U/ml. Patients were subsequently treated with a daily dose of rIFN-alpha-2C of 5 x 10(6) U. Four patients achieved a complete and six achieved a partial haematological response. Of the four non-responders three rapidly progressed into blastic crisis. Thus it was seen that treatment failure to interferon was accompanied by IFN-resistance in vitro of BFU-E, CFU-GM and/or CFU-Meg colony formation by bone marrow precursors (p less than 0.01). These results suggest a predictive value of IFN-sensitivity testing in vitro in Ph1 + CML.

Adult↗

Treatment of cancer patients with recombinant interferon-gamma induces release of endogenous tumor necrosis factor-alpha.

STUDY OBJECTIVE: 1) to investigate serum levels of tumor necrosis factor-alpha in patients treated with recombinant interferon-gamma and 2) to relate changes in TNF serum levels to other biological responses observed during treatment with interferon gamma (IFN-gamma). PATIENTS: Five patients suffering from metastasizing renal cell carcinoma. INTERVENTION: Each patient received three treatment cycles of 10 micrograms, 100 micrograms and 500 micrograms IFN-gamma applied three times at weekly intervals. The treatment cycles were separated by a therapy free interval of two weeks. The order of dose levels was randomly assigned to each patient. MEASUREMENTS AND MAIN RESULTS: Tumor necrosis factor alpha (TNF-alpha), IFN-gamma and neopterin serum levels, monocyte counts in the peripheral blood and body temperature were measured immediately before and 4, 24, 48, 72, and 168 h after each application of IFN-gamma. Results indicated that elevated serum levels of TNF-alpha are induced by 100 micrograms and 500 micrograms IFN-gamma. Repeated application of the same dose led to downregulation of TNF release into the serum. Changes in TNF serum levels did not correlate with the magnitude of febrile reactions, neopterin production or IFN-gamma serum levels.

Aged↗

Evaluation of cytokines and cytokine-induced secondary messages in sera of patients after liver transplantation.

The study objective was first to investigate serum levels of tumor necrosis factor alpha, interleukin 1 beta, interferon gamma, interferon alpha, interleukin 2, beta-2-microglobulin (B2M), and urinary neopterin in patients after orthotopic liver transplantation; and second to relate their levels to clinical complications. The design used was the prospective observation study, and the setting used was the transplant unit of a university medical center. Serum samples were collected from 20 patients every alternate day from transplantation until discharge. The measurements and main results were as follows: concentrations of cytokines, B2M, and neopterin were performed using commercially available radioimmuno-assays. In seven out of nine patients with acute cellular rejections, elevated levels of TNF-alpha, IFN-gamma, IL-1, B2M, and neopterin were detected. The highest absolute levels of TNF-alpha were observed in patients with CMV disease. Increments in bacterial infections were comparable to those seen in the above-mentioned groups with the exception of IFN-gamma, which remained stable. IL-1 serum levels showed a different pattern with peak concentrations measured in sera before transplant and during rejection, while in the case of CMV disease levels gradually decreased. No detectable levels of IFN-alpha or IL-2 were observed. Our results indicate that enhanced endogenous production of TNF-alpha and IFN-gamma accompanied by elevated levels of B2M and neopterin represent a regular feature of inflammatory complications after liver transplantation. Serum cytokine levels however were not useful in distinguishing between rejection and infection. Evaluation of neopterin was more sensitive than cytokine or B2M measurement for the detection of inflammatory complications.

Adolescent↗

Endogenous IFN-gamma during human bone marrow transplantation. Analysis of serum levels of interferon and interferon-dependent secondary messages.

Serum levels of interferon-gamma and the IFN-dependent marker molecules neopterin and beta 2-microglobulin were assessed in BMT recipients. Concentrations of the latter two markers were corrected for creatinine levels in order to eliminate the impact of alteration of kidney function. Serum levels were assessed daily using commercially available radioimmunoassays. Twelve patients were studied during the early phase of allogeneic bone marrow transplantation and eleven additional patients during complications of BMT. Results indicated that both the conditioning regimen for BMT as well as major clinical complications such as infection and acute graft-versus-host disease strongly influence the endogenous patterns of the lymphokine and its secondary messages. During allogeneic BMT IFN-gamma and neopterin levels exhibited a biphasic pattern with a first peak during conditioning with high-dose cyclophosphamide and a second still higher peak at the time of hemopoietic regeneration. beta-2-microglobulin ratios increased during conditioning and remained elevated throughout observation. Serious infections of bacterial and viral origin as well as GvHD were accompanied by elevated levels of all three serum parameters studied. The kinetics of enhanced endogenous production, however, differed between infectious complications and GvHD. Increasing concentrations were observed during infections subsequent to clinical manifestation, whereas they preceded disease manifestation in GvHD.

Biopterins↗