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T Sauerbruch

Publications and source records attributed to T Sauerbruch.

At least 127 records · Page 7Linked to original sources
PubMed2000

[Orthotopic liver transplantation in a 33-year-old patient with fulminant hepatitis B and HIV infection].

HISTORY AND CLINICAL FINDINGS: A 33-year-old man with fulminant hepatitis B infection was to have an orthotopic liver transplantation (OLTX) because of the otherwise poor prognosis. During preparations for it he was found also to have an HIV-infection. INVESTIGATIONS: Preoperatively the Quick value was 9%, and he had a grade 2 encephalopathy. His immune status was impaired: 477 CD4-T-helper cells/microliter. Virus load, measured with a quantitative HIV-RNA test, was < 80 copies/ml (i.e. below demonstrable level). DIAGNOSIS, TREATMENT AND COURSE: After the first transplantation had ended in organ failure, a second one two days later was successful. But there were several complications postoperatively: ischaemic-toxic tubular renal failure requiring haemodialysis, underperfusion of the right lobe of the liver due to arterial stenosis, pleural effusion, cytomegalovirus infection and cyclosporin-induced hypertension. But all these were successfully managed. At the time of this report, 27 months later, the patient felt well and his immune state was stable. During these 2 years he had a practically normal T-helper count and HIV-RNA measured below 80 copies/ml with good liver function. There has been no indication for antiviral treatment and there have been no complications relating to immunosuppression. CONCLUSION: The low life expectancy before effective antiviral drugs are available explains the reluctance to perform OLTX in HIV-infected patients. The favourable course in this case, using highly efficacious combined antiretroviral treatment now being available, indicates that after careful consideration, OLTX can be performed in selected patients with HIV.

Adult↗
PubMed2000

T(H)1 to T(H)2 shift of cytokines in peripheral blood of HIV-infected patients is detectable by reverse transcriptase polymerase chain reaction but not by enzyme-linked immunosorbent assay under nonstimulated conditions.

BACKGROUND: Dysregulation of cytokines has been implicated in the pathogenesis of HIV infection. Therefore, we determined tumor necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta), IL-4, IL-10, and interferon-gamma (IFN-gamma) mRNA and serum levels in HIV-infected patients under nonstimulated conditions. MATERIAL AND METHODS: Blood samples of 32 HIV-infected patients and 10 healthy HIV-negative controls were analyzed. Cytokine serum levels were quantified by enzyme-linked immunosorbent assay (ELISA). Cytokine mRNA levels were determined semiquantitatively by competitive reverse transcriptase polymerase chain reaction (RT-PCR) and expressed as ratios relative to those of beta-actin. RESULTS: Competitive RT-PCR was shown to be more sensitive than protein ELISA in analyzing cytokine production. We found a significant correlation between steady-state mRNA ratios and serum protein levels for TNF-alpha. Significantly higher cytokine mRNA ratios were found in those patients with IL-10 and IFN-gamma levels detectable by ELISA. Steady-state mRNA ratios of TNF-alpha, IL-4, and IL-10 were significantly increased in patients with highly replicative HIV-infection. Furthermore, elevated IL-4:IFN-gamma ratios were related to both high viral load and loss of CD4 cells. DISCUSSION: Determination of steady-state mRNA ratios by semiquantitative RT-PCR represents a sensitive method to analyze cytokines in peripheral blood of HIV-infected patients under nonstimulated conditions. The data obtained with this technique provide further evidence for a T(H)1 to T(H)2 cytokine shift with progressive HIV disease.

CD4 Lymphocyte Count↗
PubMed2000

A hepatitis C virus (HCV) core protein derived peptide inhibits HCV specific lymphocyte proliferation.

T helper lymphocytes are important regulatory cells for the immune response in chronic hepatitis C. They recognize peptides, which are generated from the viral proteins by antigen processing and are bound to MHC (major histocompatibility complex) class II molecules. However, antigen processing might also result in non-immunogenic peptide fragments that can modify T cell activation. - To identify such peptide fragments in hepatitis C, we studied binding of 15 synthetic HCV core derived peptides to MHC class II molecules of 9 human homozygous typing B cell lines (HT-BCLs) as well as T cell proliferation in 41 HLA-typed patients with chronic hepatitis C. - We identified a peptide (HCV core aa 59-83) which bound to 7 HT-BCLs, whereas PBMC of only 2 out of 36 patients with the corresponding HLA-DR alleles proliferated in response to this peptide. Competition experiments indicated that small amounts of peptide aa 59-83 specifically inhibited the proliferative response to the recombinant core protein but not to core derived immunogenic peptides. Our data show that a peptide fragment from the HCV core region aa 59-83 can interfere in vitro with immune recognition of the HCV core protein.

B-Lymphocytes↗
PubMed2000

Prediction of imminent complications in HIV-1-infected patients by markers of lymphocyte apoptosis.

OBJECTIVE: The aim of the study was to compare accepted surrogate markers of HIV disease progression with markers of lymphocyte apoptosis in their ability to predict short-term disease progression. METHODS: In all, 40 HIV-positive patients were studied prospectively and observed during follow-up for HIV-related adverse clinical events. Ex vivo apoptosis was measured with the markers CD95 expression, annexin V binding, and Apostain dye uptake by flow cytometry at baseline. Established markers of disease progression (CD4 count, HIV-RNA level, and CD8/38 count), CD8, B-cell, and natural killer (NK) cell counts were determined by standard procedures at baseline and after 6 months. RESULTS: In HIV-infected patients, CD95 expression and annexin V binding showed significantly elevated apoptosis in peripheral blood lymphocytes and all lymphocyte subsets at baseline compared with HIV-negative, healthy controls. Apostain failed to differentiate between HIV-infected patients and healthy controls. HIV-related complications could be predicted by CD4 and CD8/38 counts, but not HIV viral load as assessed by relative operating characteristic (ROC) analysis (CD4, p = .003; CD8/38, p = .031). A similar or even better diagnostic accuracy was found for CD95 expression in total lymphocytes (p<.001), the CD4+ (p = .003) and CD8+ (p = .005) T-cell subsets and for annexin V binding in CD4+ T cells (p = .005). When patients with CD4 counts <200 cells/microl were analyzed separately, only annexin V binding in CD4+ T cells, but none of the other prognostic markers could predict complications (p = .001). CONCLUSION: Determination of annexin V binding on CD4+ T cells may be a useful tool to monitor HIV-infected patients with low (<200 cells/microl) CD4 counts, as it can reliably assess the risk for imminent complications in such patients.

AIDS-Related Opportunistic Infections↗
PubMed2000

Combinations of the cytokines IL-12, IL-2 and IFN-alpha significantly augment whereas the cytokine IL-4 suppresses the cytokine-induced antibody-dependent cellular cytotoxicity of monoclonal antibodies 17-1A and BR55-2.

Since some cytokines effectively enhance the cytotoxicity of monoclonal antibodies, we investigated whether a combination of cytokines can augment the antibody-dependent cellular cytotoxicity (ADCC) of monoclonal antibodies 17-1A and BR55-2 against the colorectal carcinoma cell line HT29. Since monocytes/macrophages are important effector cells for ADCC, we used a new flow cytometric cytotoxicity assay, which allows the analysis of long-term-ADCC exerted by these cells. In our previous studies with peripheral blood mononuclear cells from normal donors, we found that IL-2, IL-12 and IFN-alpha increase ADCC. Therefore, we examined whether combination of these three cytokines with IL-2, IL-4, IL-6, IL-10, IL-12, IFN-alpha, IFN-gamma, GM-CSF, M-CSF and TNF-alpha may yield higher ADCC than obtained by the application of single cytokines. Indeed, we found that the combinations IL-2/IFN-alpha, IL-2/IL-12 and IL-12/IFN-alpha potentiated ADCC. Interestingly, the ineffective single cytokines TNF-alpha and GM-CSF in the combinations IL-2/TNF-alpha, IFN-alpha/TNF-alpha and IFN-alpha/GM-CSF also proved to enhance ADCC. In contrast, IL-4 significantly suppressed the IL-2, IL-12 and IFN-alpha-induced ADCC. In addition, the immunosuppressive cytokine IL-10 in higher concentrations significantly suppressed the IL-12-induced-ADCC. Our results may be useful to find combinations of cytokines and mAb for the treatment of cancer.

Antibodies, Monoclonal↗
PubMed2000

A bispecific single-chain antibody directed against EpCAM/CD3 in combination with the cytokines interferon alpha and interleukin-2 efficiently retargets T and CD3+CD56+ natural-killer-like T lymphocytes to EpCAM-expressing tumor cells.

Cytokine-induced killer cells (CIK), generated in vitro from peripheral blood mononuclear cells (PBMC) by addition of interferon gamma (IFNgamma), interleukin-2 (IL-2), IL-1 and a monoclonal antibody (mAb) against CD3, are highly efficient cytotoxic effector cells with the CD3+CD56+ phenotype. In this study, we evaluated whether the cytotoxicity of these natural-killer-like T lymphocytes against the colorectal tumor cell line HT29 can be enhanced by the addition of a bispecific single-chain antibody (bsAb) directed against EpCAM/CD3. For determination of bsAb-redirected cellular cytotoxicity we used a new flow-cytometric assay, which directly counts viable tumor cells and can assess long-term cytotoxicity. We found that this bsAb induced distinct cytotoxicity at a concentration above 100 ng/ml with both PBMC and CIK at an effector-to-target cell ratio as low as 1:1. CIK cells revealed higher bsAb-redirected cytotoxicity than PBMC. Cellular cytotoxicity appeared after 24 h whereas PBMC showed the highest bsAb-redirected cytotoxicity after 72 h. The addition of the cytokines IL-2 and IFNalpha but not granulocyte/macrophage-colony-stimulating factor enhanced bsAb-redirected cytotoxicity of both PBMC and CIK. When the bsAb was combined with the murine mAb BR55-2, which recognizes the Lewis(Y) antigen, bsAb-redirected cytotoxicity was partly augmented, whereas murine mAb 17-1A, which binds to EpCAM as well, slightly suppressed bsAb-redirected cytotoxicity induced by the bsAb. We conclude that CIK generated in vitro or in vivo combined with this new EpCAM/CD3 bsAb and the cytokine IL-2 should be evaluated for the treatment of EpCAM-expressing tumors.

Animals↗
PubMed2000

Increase in the immunostimulatory effect of dendritic cells by pulsing with serum derived from pancreatic and colorectal cancer patients.

Both we and others have observed a relative resistance of solid tumor cells to immunological effector cells in vitro, which may be one reason for the clinical phenomenon of resistance of patients with pancreatic carcinoma or other solid tumors to immunological therapeutic approaches. Dendritic cells (DC) are professional antigen-presenting cells which can process and present tumor-associated antigens such as CA 19-9. Here we tested DC pulsed with serum containing CA 19-9 for their capacity to stimulate immunological effector cells against pancreatic carcinoma cells. Coculture of immunological effector cells with DC led to a significant increase in cytotoxic activity as measured by a lactic dehydrogenase release assay. Most interestingly, cytotoxic activity against tumor cells was further increased using DC pulsed with patient-derived CA 19-9 containing serum. Similar results have been obtained using either autologous or allogeneic serum from patients with pancreas carcinoma. The effect of serum on the cytotoxicity of effector cells increased in a dose-dependent manner. Interestingly, heat inactivation led to a significant loss of immunostimulatory capacity of the serum. Cytotoxicity was partially inhibited by using an antibody directed against CA 19-9 on the surface of the target cells. Best results were obtained when adding CA 19-9 protein to CA 19-9 containing serum for pulsing of DC. In conclusion, DC pulsed with CA 19-9 containing serum increased the cytotoxic activity of immunological effector cells against pancreatic cancer cells. DC pulsed with CA 19-9 containing serum with or without additional exogenous CA 19-9 protein may have an impact on immunotherapeutic protocols for patients with CA 19-9 secreting tumors.

CA-19-9 Antigen↗
PubMed2000

Fatal pneumonia in an AIDS patient coinfected with adenovirus and Pneumocystis carinii.

BACKGROUND: Adenovirus infections are common in immunocompromised hosts. However, pulmonary adenovirus infections rarely cause significant morbidity in HIV-infected patients. PATIENT: Here we describe a 27-year-old man with AIDS who presented with tachypnea, hypoxemia and an infiltrate in the upper left lobe on chest X-ray. Bronchoscopy was performed and Pneumocystis carinii was detected in bronchoalveolar lavage (BAL) fluid. Treatment with cotrimoxazole and prednisone initially resulted in improvement, but after 10 days the patient's clinical condition deteriorated rapidly and he died after 23 days due to respiratory failure. RESULTS: On autopsy histopathologic examination showed abundant "smudge cells," suggestive of adenoviral infection. Electron microscopy revealed adenovirus-like particles arrayed in a paracrystalline manner. Subsequent immunohistochemistry confirmed the extensive presence of adenovirus in addition to P. carinii. CONCLUSION: This case demonstrates a pathogenetic role for adenovirus coinfection in P. carinii pneumonia (PCP). Earlier diagnosis, e.g. by PCR analysis of the BAL fluid or transbronchial biopsy, might have led to the consideration of ribavirin treatment.

AIDS-Related Opportunistic Infections↗
PubMed2000

"Atypical p-ANCA" in IBD and hepatobiliary disorders react with a 50-kilodalton nuclear envelope protein of neutrophils and myeloid cell lines.

BACKGROUND & AIMS: Atypical "antineutrophil cytoplasmic antibodies" (ANCA) are present in patients with ulcerative colitis (UC), primary sclerosing cholangitis (PSC), and autoimmune hepatitis (AIH). Recently, we showed that atypical p-ANCA react with nuclear envelope proteins of neutrophils. Based on this observation, we aimed to characterize the nuclear antigen recognized by atypical p-ANCA. METHODS: We prepared cytoplasmic and nuclear extracts of human neutrophils, human HL-60, and murine 32D myeloid cells. Proteins were resolved by 1- and 2-dimensional gel electrophoresis. Reactive proteins were detected by immunoblotting with sera from 118 individuals (UC, 25; PSC, 28; AIH, 35; disease and normal controls, 30). Atypical p-ANCA (n = 64) were affinity-purified against the reactive protein and investigated for their immunofluorescence pattern using confocal microscopy. RESULTS: Immunoblotting showed reactivity to a myeloid-specific 50-kilodalton nuclear protein with an isoelectric point of pH 6.0 detected in 92% (59 of 64) of the patients with inflammatory bowel or hepatobiliary diseases and atypical p-ANCA. Affinity-purified antibodies against the 50-kilodalton protein gave a nuclear rim-like fluorescence on myeloid cells examined by immunofluorescence microscopy. Affinity-purified antibodies did not recognize antigens in nonmyeloid cells. CONCLUSIONS: Atypical p-ANCA in UC, PSC, or AIH recognize a 50-kilodalton myeloid-specific nuclear envelope protein.

Adolescent↗
PubMed2000

[Therapy-refractory thrombocytopenia in chronic hepatitis C].

HISTORY AND CLINICAL FINDINGS: A 74-year-old man known to be suffering from a chronic hepatitis C infection was hospitalized because of intestinal hemorrhage, multiple petechiae and suggillations. The patient had received oral anticoagulant medication after replacement of the mitral valve. The intake of oral vitamin K antagonist had been discontinued eight days before admission. EXAMINATION FINDINGS: On admission, the platelet count was 3 G/l, the Quick's test 72%. Colonoscopy revealed diffuse mucosal bleeding in the proximal colon. Bone marrow examination showed moderate hyperplasia of erythropoiesis, as well as a marked increase in megakaryocytes. DIAGNOSIS, THERAPY AND COURSE: The diagnosis was hepatitis C-associated idiopathic thrombocytopenic purpura. The administration of both immunoglobulins and prednisone failed to increase platelets sufficiently. There was also no improvement after administration of Danazol. However, six days after a single application of cyclophosphamide (2,000 mg on day 1), a continuous increase of platelets to 100 G/l was obtained, a level which has remained stable for the last 18 months. CONCLUSION: The differential diagnosis of a hepatitis C-associated autoimmune thrombocytopenia must be considered in patients with chronic hepatitis C infection and severe thrombocytopenia. In cases of refractory disease, treatment with cyclophosphamide may be successful. This is particularly appropriate if, in the case of an insufficient increase in thrombocytes following administration of immunoglobulins, the success of a splenectomy is improbable, or when a splenectomy must be excluded because of relative or absolute contraindications.

Aged↗
PubMed2000

Prestimulation of monocytes by the cytokines GM-CSF or IL-2 enhances the antibody dependent cellular cytotoxicity of monoclonal antibody 17-1A.

Previously, we have shown that the cytokines IFN-alpha, IFN-gamma and IL-2 significantly enhance the antibody dependent cellular cytotoxicity (ADCC) exerted by the monoclonal antibody (mAb) 17-1A which recognizes the tumor associated antigen EpCAM. ADCC was assessed by a new flow cytometric cytotoxicity assay using the PKH2 labeled colorectal tumor cell line HT29 as target cells and peripheral blood mononuclear cells as effectors. Monocytes are assumed to be one of the major effectors for ADCC. However, isolated monocytes have a rather low ADCC capacity while addition of CD4+ lymphocytes optimizes ADCC. Since such an interaction between immune cells may act through cytokines we investigated whether a seven-day-prestimulation of monocytes by the cytokines M-CSF, GM-CSF, IFN-gamma, IFN-alpha and IL-2 enhances ADCC. Thereafter, we added for three days IL-2 and IFN-alpha with or without the mAb 17-1A for terminal activation of monocytes. Interestingly, GM-CSF which was ineffective in terminal activation, significantly enhanced ADCC of monocytes when it was used for prestimulation. Similar results were obtained with IL-2. IFN-gamma and M-CSF were also active but less than GM-CSF. Astonishingly, IFN-gamma and IFN-alpha prestimulation of monocytes suppressed the enhancement of ADCC exerted by GM-CSF and IL-2, respectively. Our experiments suggest that the timing of cytokine application is critical for the induction of optimal ADCC. Subcutaneous pretreatment with GM-CSF or IL-2 followed by the combination of IL-2/IFN-alpha/17-1A should be evaluated in a phase I clinical trial in patients with colorectal cancer.

Antibodies, Monoclonal↗