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Hermann Einsele

Publications and source records attributed to Hermann Einsele.

71 records · Page 4Linked to original sources
PubMed2002

Ganciclovir-resistant cytomegalovirus disease after allogeneic stem cell transplantation: pitfalls of phenotypic diagnosis by in vitro selection of an UL97 mutant strain.

A 9-month posttransplantation course of an allogeneic stem-cell transplant recipient (human cytomegalovirus [HCMV] serostatus, donor positive/recipient negative), in whom ganciclovir (GCV) resistance developed (UL97 mutations M460V, L595S, and C603W) on day 164 after transplantation and who developed HCMV retinitis and fatal HCMV encephalitis is presented. Virus strains isolated from secondary cultures were analyzed by UL97 restriction assays and sequencing and were compared with primary DNA extracts of the same specimens, which resulted in molecular proof of an initial HCMV strain-specific in vitro selection of the in vivo nondominant UL97 L595S-C603 mutant strain from 3 viral variants present in vivo. In addition, compartmentalization of virus present in blood and cerebrospinal fluid was found. The influence of rapidly increasing plasma virus load (to >10(6) copies/mL) and oral administration of GCV on the emergence of GCV resistance is shown. These findings have strong implications for the diagnosis of HCMV drug resistance.

Antiviral Agents↗
PubMed2002

Analysis of T-cell responses to Aspergillus fumigatus antigens in healthy individuals and patients with hematologic malignancies.

Invasive aspergillosis has become a major cause of infection-related mortality in nonneutropenic patients after allogeneic stem cell transplantation (SCT). To assess the potential role of Aspergillus-specific T-cell responses for the successful control of invasive aspergillosis, lymphoproliferative responses to Aspergillus fumigatus antigens were studied in healthy individuals, patients with evidence of invasive aspergillosis, and patients late after allogeneic SCT. In healthy individuals, a positive lymphoproliferative response was documented to cellular extracts of A fumigatus (14 of 16), the 88-kDa dipeptidylpeptidase (4 of 16), and the 90-kDa catalase (8 of 11). A predominant release of interferon gamma (IFN-gamma) in culture supernatants on stimulation with A fumigatus antigens was demonstrated in 13 of 17 healthy individuals, indicating a T(H)1 response. In patients with clinical evidence of invasive aspergillosis, a favorable response to antifungal therapy was found to correlate with a higher IFN-gamma/interleukin 10 (IL-10) ratio in culture supernatants (n = 7; median ratio, IFN-gamma/IL-10 = 1.0; range, 0.09-24.8) compared to 10 patients with progressive or stable disease (median ratio, IFN-gamma/IL-10 = 0.1; range, 0.002-2.1; P =.04). Steroid treatment was found to suppress Aspergillus-specific lymphoproliferation (P =.037) and release of IFN-gamma in culture supernatants (P =.017). In contrast to cytomegalovirus- and tetanus toxoid-specific T-cell responses, Aspergillus-specific T-cell reconstitution late after allogeneic SCT was characterized by low stimulation indices and a low IFN-gamma/IL-10 ratio. In addition, phosphoantigen-reactive V(gamma)9/V(delta)2 T-cell clones from healthy individuals were found to produce significant amounts of tumor necrosis factor in response to A fumigatus antigens. In conclusion, these results further support the hypothesis that T cells contribute to the host defense against A fumigatus.

Adolescent↗
PubMed2002

Infusion of cytomegalovirus (CMV)-specific T cells for the treatment of CMV infection not responding to antiviral chemotherapy.

We adoptively transferred donor-derived cytomegalovirus (CMV)-specific T-cell lines into 8 stem cell transplant recipients lacking CMV-specific T-cell proliferation. All patients, of whom one was infected by a CMV strain that was genotypically ganciclovir resistant, had received unsuccessful antiviral chemotherapy for more than 4 weeks. CMV-specific lines had been prepared by repetitive stimulation with CMV antigen, which increased the percentage of CMV-specific T cells and ablated alloreactivity completely even against patients mismatched for 1 to 3 HLA antigens. After transfer of 10(7) T cells/m(2) at a median of 120 days (range, 79-479 days) after transplantation, no side effects were noticed. Despite cessation of antiviral chemotherapy, the CMV load dropped significantly in all 7 evaluable patients, with a maximal reduction after a median of 20 days (range, 5-31 days). In 2 patients with high virus load, the antiviral effect was only transient. One of these patients received a second T-cell infusion, which cleared the virus completely. At a median of 11 days after transfer, CMV-specific T-cell proliferation was demonstrated in 6 patients, and an increase in CMV-specific CD4(+) T cells was demonstrated in 5 patients. In 6 patients, 1.12 to 41 CMV-specific CD8(+) T cells/microL blood were detected at a median of 13 days after transfer, with an increase in all patients lacking CMV-specific CD8(+) T cells prior to transfer. Hence, anti-CMV cellular therapy was successful in 5 of 7 patients, whereas in 2 of 7 patients, who received an intensified immune suppression at the time of or after T-cell therapy, only transient reductions in virus load were obtained.

Adoptive Transfer↗
PubMed2002

Sensitive detection of human cytomegalovirus peptide-specific cytotoxic T-lymphocyte responses by interferon-gamma-enzyme-linked immunospot assay and flow cytometry in healthy individuals and in patients after allogeneic stem cell transplantation.

Reconstitution of human cytomegalovirus (HCMV)-specific cytotoxic T lymphocytes (CTLs), predominantly directed against pp65, provides protective immunity for the development of HCMV disease after allogeneic stem cell transplantation (SCT). To define pp65-derived CTL epitopes that would allow sensitive detection of HCMV-specific immune reconstitution, a computer-based epitope prediction was performed. Peptide-specific CTL responses were assessed by interferon-gamma release. With this approach, pp65-derived epitopes presented by the HLA alleles A*0101, A*0201, A*1101, and B*0702 were identified. The frequency of CTLs in healthy HCMV-seropositive individuals ranged from about 0.1% to 3.3% of all CD8(+) T cells. In patients at risk of HCMV infection after allogeneic SCT, HCMV-peptide-specific CTLs were found in 14 of 19 patients at a median of 90 days after SCT (range, 35-234 days) and HCMV-antigen-specific CD4(+) T lymphocytes in 11 of 18 patients at a median of 90 days after SCT (range, 35->180 days). Peak counts of peptide-specific CD8(+) T cells ranged from 0.14 to 60.6 cells/microL; those of protein-specific CD4(+) T cells ranged from 0.64 to 18.97 cells/microL. Reconstitution of HCMV-peptide-specific CD8(+) T cells and protein-specific CD4(+) T cells was associated with clearance of HCMV infection (r(2) = 0.89, P <.0001 and r(2) = 0.61, P =.0045, respectively). HCMV infection recurred after documentation of HCMV-specific T-cell reconstitution (n = 4) when immunosuppression was intensified. Patients in whom late-onset HCMV disease developed lacked HCMV-protein-specific T cells at 3 months after SCT. In conclusion, prospective monitoring of HCMV-specific CD4(+) and CD8(+) T-cell reconstitution can be performed rapidly by using flow cytometry after specific stimulation with HCMV peptides and proteins and might help to further improve clinical management of HCMV infection after allogeneic SCT.

Adult↗
PubMed2002

Polymerase chain reaction detection of aspergillus DNA in experimental models of invasive aspergillosis.

To determine the sensitivity of polymerase chain reaction (PCR) assays for the diagnosis of invasive aspergillosis, results of quantitative culture, PCR-ELISA, and a quantitative LightCycler assay (Roche Diagnostics) of blood and organ specimens of experimentally infected mice and rabbits were compared. By PCR-ELISA, 297 of 379 murine lung specimens were positive, but only 235 of 379 were culture positive. Whereas 64 culture-negative lungs were positive by PCR, Aspergillus was grown from only 2 PCR-negative samples. The PCR assay was 19.4 times more sensitive than culture. None of the 68 blood cultures from mice and rabbits were positive for Aspergillus fumigatus, whereas PCR detected Aspergillus DNA in 17 of 68 blood samples. Quantitative PCR analysis of blood samples showed a fungus load of 10(1)-10(2) cfu/mL of blood. The data confirm the superior sensitivity of PCR for the diagnosis of experimental Aspergillus infections.

Animals↗
PubMed2002

Randomized multicenter trial of foscarnet versus ganciclovir for preemptive therapy of cytomegalovirus infection after allogeneic stem cell transplantation.

The present study compared foscarnet with ganciclovir for preemptive therapy of cytomegalovirus (CMV) infection after allogeneic blood or marrow stem cell transplantation (SCT). Patients with CMV infection, as detected by weekly antigenemia or polymerase chain reaction (PCR) in blood leukocytes, were randomized to intravenous therapy for 2 weeks with either foscarnet at 60 mg/kg or ganciclovir at 5 mg/kg administered every 12 hours; if CMV infection remained detectable, patients received an additional 2 weeks of intravenous foscarnet at 90 mg/kg or ganciclovir at 6 mg/kg given once daily for 5 days per week, after which therapy was stopped. Primary efficacy endpoint was the occurrence of CMV disease or death from any cause within 180 days after SCT. A total of 213 patients were treated with either foscarnet (n = 110) or ganciclovir (n = 103). Kaplan-Meier estimates of event-free survival within 180 days after SCT were similar in the 2 treatment groups (P =.6). During study treatment, severe neutropenia (< 0.5 x 10(9)/L) occurred in 11 (11%) patients on ganciclovir versus 4 (4%) patients on foscarnet (P =.04), and impaired renal function was observed in 5 (5%) patients on foscarnet versus 2 (2%) patients on ganciclovir (P =.4). Neutropenia or thrombocytopenia required discontinuation of ganciclovir in 6 (6%) patients but in no foscarnet-treated patient (P =.03). After allogeneic SCT, preemptive therapy of CMV infection with foscarnet shows similar efficacy as with ganciclovir, but is associated with a lower proportion of patients who develop severe neutropenia and who require discontinuation of antiviral therapy due to hematotoxicity.

Adolescent↗
PubMed2002

Epstein-Barr viral load as a tool to diagnose and monitor post-transplant lymphoproliferative disease.

Epstein-Barr virus (EBV)-induced post-transplant lymphoproliferative disease (PTLD) continues to be a rare but severe complication following transplantation. EBV viral load is used as a tool to identify patients at risk for developing PTLD. However, studies on EBV viral load are hard to compare since study design as well as EBV detection method and calculation of results are highly variable. In the majority of cases EBV viral load is increased in patients with PTLD compared to patients without disease. There is, however, some overlap. Some individual patients with only low viral load show PTLD while others show the opposite. The major future goals will be to standardize EBV-DNA detection in order to generate comparable data in different centers and to establish cut-off values to distinguish patients with PTLD from patients without with a high precision.

DNA, Viral↗
PubMed2002

Isolation and expansion of human cytomegalovirus- specific cytotoxic T lymphocytes using interferon-gamma secretion assay.

OBJECTIVE: The aim of this study was to isolate and expand donor-derived human cytomegalovirus (HCMV)-specific cytotoxic T lymphocytes (CTLs) for adoptive transfer of 10(7) cells per m(2) of body surface area to restore protective immunity after stem cell transplantation. MATERIALS AND METHODS: A new strategy to generate HCMV-specific CTLs using the interferon-gamma (IFN-gamma) secretion assay, followed by expansion to numbers sufficient for clinical application with interleukin-2 and feeder cell stimulation, is described. RESULTS: From 1 to 5 x 10(4) HCMV peptide-specific T lymphocytes (greater than 90% CD3(+)CD8(+)) were isolated from 1 to 2 x 10(8) peripheral blood mononuclear cells comparable to 50 to 100 mL of blood from HLA-A*0201 HCMV seropositive blood donors (n = 14) and expanded ex vivo after a median of 16 days (range 8-28 days; n = 13) to greater than 10(7)/m(2) HCMV peptide-specific CTLs using autologous (n = 2) or allogeneic (n = 11) feeder cell stimulation. In three experiments, expansion to 6 weeks was performed, achieving a median of 1.6 x 10(9) cells (range 6.1 x 10(8)-3.3 x 10(9)). Characterization of these HCMV-specific CTL lines revealed an average purity of 89.2% (range 66.2-99.3%) using HCMV pp65 peptide HLA-A*0201 tetramer staining (n = 14) and 89.4% (range 64.4-99.5%) by peptide-specific IFN-gamma secretion (n = 7). A median of 82.6% (range 76.0-88.0%) showed perforin secretion (n = 3) and 57.5% (range 22.2-80.7%) specific lysis of peptide-pulsed T2 cells (n = 5). A median of 52.2% (range 35.2-7.3%) revealed specific killing of HCMV-infected autologous, but not allogeneic, fibroblasts (n = 6). CONCLUSIONS: IFN-gamma secretion assay allows development of a simple and rapid protocol with short expansion times for generation of greater than 10(7)/m(2) HCMV-specific CTLs for adoptive immunotherapy.

Adoptive Transfer↗
PubMed2002

Human cytomegalovirus induces a direct inhibitory effect on antigen presentation by monocyte-derived immature dendritic cells.

The hypothesis that productive infection of monocyte-derived immature dendritic cells (DCs) by the human cytomegalovirus (HCMV) is associated with decreased immunostimulatory capacity was tested in this study. DCs were infected with 60-80% efficiency by HCMV strain TB40/E. Infected versus uninfected cells were analysed by fluorescence-activated cell sorting and by immunocytochemistry for surface expression of major histocompatibility complex (MHC) and co-stimulatory molecules as well as cytokine secretion during the 3 d after infection. The immunostimulatory capacity of these cells was measured by mixed leucocyte reaction. In spite of the fact that HCMV infection of DCs induced an increased release of tumour necrosis factor-alpha (TNF-alpha) and a decreased interleukin 10 (IL-10) production, expression of MHC class I and II, as well as CD40 and CD80 molecules, were downregulated on infected DCs. The mixed leucocyte reaction showed significantly reduced immunostimulatory capacity of infected DC cultures. Simultaneous detection of MHC antigens and virus antigens by double immunofluorescence revealed that downregulation occurred only on infected cells, but not on uninfected bystander cells. These findings demonstrate on a single cell level, together with the marked downregulation of MHC and co-stimulatory molecules in the presence of high TNF-alpha and low IL-10 levels, a direct inhibitory effect of HCMV on antigen presentation by immature DCs independent of soluble mediators.

Antigen Presentation↗
PubMed2002

Characterization and functional analysis of granulocyte concentrates collected from donors after repeated G-CSF stimulation.

BACKGROUND: Neutropenic patients often develop bacterial or fungal infections not responding to broad-spectrum antibacterial or antifungal agents. Clinical efforts were made with transfusion of granulocyte concentrates; however, functions of granulocytes after multiple G-CSF stimulations and after apheresis are not yet investigated and described sufficiently. STUDY DESIGN AND METHODS: The aim of this study was to characterize functional and immunologic variables of granulocytes in blood samples drawn from donors before and after each stimulation episode with G-CSF, in the resulting granulocyte concentrates and in the patients 8 hours after transfusion. RESULTS: Chemotaxis was not influenced, neither by G-CSF application nor by apheresis. Multiple G-CSF stimulations enhanced oxidative burst and phagocytosis of Escherichia coli in donor granulocytes. These values returned to basal levels in granulocyte concentrates. Expression of granulocytic surface antigens was downregulated after application of G-CSF but returned to normal and in part enhanced values in concentrates. A clinically relevant increase of proinflammatory cytokines could not be detected. Leukotriene B4 production was reduced after the fourth G-CSF stimulation in the donor blood and enhanced in the granulocyte concentrate after apheresis. Results in recipients indicate that changes of granulocyte function noted in concentrates were only transient. CONCLUSION: Stimulation of healthy donors with repeated G-CSF injections and subsequent granulocyte apheresis does not dramatically change decisive functions of granulocytes.

Adult↗
PubMed2002

Cellular immunity to viral and fungal antigens after stem cell transplantation.

Cellular immunity to viral and fungal antigens is often suppressed after stem cell transplantation. Viral infections, in particular infections with cytomegalovirus and Epstein-Barr virus, are often reactivated after allogeneic stem cell transplantation. Pathogenetic factors are immune deficiency and T-cell stimulation in the course of graft-versus-host reactions. Fungal infections are opportunistic infections derived with ubiquitous microorganisms. Immune deficiency, neutropenia, steroid treatment, and antibiotic treatment contribute to the pathogenesis. The study of viral and fungal immunity after allogeneic stem cell transplantation gives insight into the reconstitution of the immune system and tolerance.

Antigens, Fungal↗
PubMed2002

Evaluation of use of Epstein-Barr viral load in patients after allogeneic stem cell transplantation to diagnose and monitor posttransplant lymphoproliferative disease.

Epstein-Barr virus (EBV)-induced posttransplant lymphoproliferative disease (PTLD) continues to be a serious complication following transplantation. The aim of the present study was to evaluate the EBV load as a parameter for the prediction and monitoring of PTLD. The EBV load was analyzed by a quantitative competitive PCR with 417 whole-blood samples of 59 patients after allogeneic stem cell transplantation (SCT). The EBV load was positive for all 9 patients with PTLD and for 17 patients without PTLD. The viral loads of patients with manifest PTLD differed from the loads of those without PTLD (median loads, 1.4 x 10(6) versus 4 x 10(4) copies/microg of DNA; P < 0.0001). A threshold value of 10(5) copies/microg of DNA showed the best diagnostic efficacy (sensitivity, 87%; specificity, 91%). However, in patients with less than three major risk factors for PTLD, the positive predictive value of this threshold was rather low. One week prior to the manifestation of PTLD, the EBV load was as low in patients who developed PTLD as in patients without disease (median, 2.2 x 10(4) copies/microg of DNA; P was not significant). EBV DNA tested positive first at 20 to 71 days prior to the clinical manifestation of PTLD and occurred with the same delay after transplantation regardless of disease (median delay, 52 versus 63 days; P was not significant). EBV DNA was detected earlier in patients with primary infections than in those with reactivations (33 versus 79 days; P = 0.01), but the peak levels were similar in the two groups. EBV primary infection or EBV reactivation is frequent in patients after allogeneic SCT but results in PTLD only in a subgroup of patients. Although evaluation of the EBV load has limitations, the EBV load represents a valuable parameter to guide therapy.

Adolescent↗
PubMed2002

Automated extraction of genomic DNA from medically important yeast species and filamentous fungi by using the MagNA Pure LC system.

A fully automated assay was established for the extraction of DNA from clinically important fungi by using the MagNA Pure LC instrument. The test was evaluated by DNA isolation from 23 species of yeast and filamentous fungi and by extractions (n = 28) of serially diluted Aspergillus fumigatus conidia (10(5) to 0 CFU/ml). Additionally, DNA from 67 clinical specimens was extracted and compared to the manual protocol. The detection limit of the MagNA Pure LC assay of 10 CFU corresponded to the sensitivity when DNA was extracted manually; in 9 of 28 runs, we could achieve a higher sensitivity of 1 CFU/ml blood, which was found to be significant (p <or= 0.004). DNA from all fungal species analyzed could be extracted and amplified by real-time PCR. Negative controls from all MagNA Pure isolations remained negative. Sixty-three clinical samples showed identical results by both methods, whereas in 4 of 67 samples, discordant results were obtained. Thus, the MagNA Pure LC technique offers a fast protocol for automated DNA isolation from numerous fungi, revealing high sensitivity and purity.

DNA, Fungal↗
PubMed2002

High variability between results of different in-house tests for cytomegalovirus (CMV) monitoring and a standardized quantitative plasma CMV PCR assay.

A total of 2,718 blood samples were analyzed in five virological laboratories for the presence of cytomegalovirus (CMV) by in-house tests and one standardized plasma PCR assay. Results from in-house tests showed remarkable variability. Detection of CMV pp65 antigen or DNA from cells was more sensitive than that by plasma CMV PCR assay.

Culture Media↗
PubMed2000

Molecular methods in the diagnosis of infections in the immunocompromised host.

Despite recent developments, infection remains a major obstacle to a successful outcome in transplantation. Molecular methods have allowed for earlier diagnosis and have proven to be powerful tools for analysing the epidemiology of infectious diseases. More recently, some of these molecular methods have been commercialized, enabling standardized diagnostic techniques to be used in multicentre trials.

Journal Article↗
PubMed2000

CMV Infection in Bone Marrow and Solid Organ Transplant Patients in the Era of Antiviral Prophylaxis.

Recent developments in the diagnosis and therapy of cytomegalovirus (CMV) infection have helped to reduce CMV-associated morbidity and mortality following allogeneic bone marrow and solid organ transplantation. The clinical symptoms of active CMV infection and the prevalence of life-threatening CMV disease vary widely between different patient populations according to the type of transplant and the intensity of immunosuppression employed. Antiviral prophylaxis with aciclovir, valaciclovir and ganciclovir has been shown to reduce CMV infection and disease following organ transplantation. Antiviral drugs, in particular ganciclovir and foscarnet, have varying sideeffects, however, and antiviral resistance due to prolonged administration of ganciclovir and foscarnet has been reported recently. Short courses of pre-emptive antiviral therapy for documented CMV infection help to reduce the duration and sideeffects of therapy, offering an alternative strategy to antiviral prophylaxis. Studies are required to compare the efficacy and costs of antiviral prophylaxis with pre-emptive therapy.

Journal Article↗