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H Kirchner

Publications and source records attributed to H Kirchner.

At least 109 records · Page 6Linked to original sources
PubMed1997

HLA-dependent heterogeneous T cell response to Mycoplasma arthritidis-derived superantigen (MAS).

Mycoplasma arthritidis induces a chronic arthritis in rodents. The role of M. arthritidis-derived superantigen (MAS) in the arthritis is still a subject of controversy. MAS stimulates mouse and human T cells in a V beta-restricted manner with the subsequent liberation of cytokines. The presence of the major histocompatibility complex class II molecule is required for such a stimulation. In this study we assessed MAS-induced cytokine production in peripheral blood from patients with different rheumatic diseases and controls using an enzyme-linked immunosorbent assay. Statistically significant differences in cytokine production in response to MAS stimulation allowed the distinction of high responders and low responders within groups of patients and controls. Higher cytokine induction was statistically correlated with the HLA-DR specificities DR4, DR7 and DR12. To confirm these results, murine V beta 8.1 cytotoxic T lymphocytes (CTL) were stimulated with MAS in the presence of different HLA-DR lymphoblastoid B cells. CTL proliferation was only observed in presence of DR4 and DR7. In conclusion, MAS T cell stimulation and its subsequently cytokine production depends on the presence of certain HLA-DR specificities.

Adult↗
PubMed1997

Diminished production of type-I interferons and interleukin-2 in patients with multiple sclerosis.

Several lines of evidence have supported the role of immunological mechanisms in the pathogenesis of multiple sclerosis (MS) and new immunomodulatory strategies for its treatment, e.g. subcutaneous application of interferon (IFN)-beta, have emerged. We investigated the ability of peripheral blood mononuclear cells (PBMC) in 21 consecutive patients with clinically definite MS to produce interferons and lymphokines in response to viral or mitogenic stimulation. Ten patients showed clinical signs of disease activity (acute relapse) and 11 patients were in a stable condition. Additionally, white blood count, leukocyte differentiation and lymphocyte subtyping were performed. A group of age-related healthy blood donors served as control (n=20). There was no difference between patients and controls in the production of IFN-gamma, tumor necrosis factor (TNF)-alpha and soluble interleukin (IL)-2 receptor. IFN-alpha and IFN-beta responsiveness, however, was significantly lower in patients with stable disease than in patients with active disease and controls (p<0.001). Furthermore, secretion of IL-2 after stimulation was significantly diminished in both patient groups as compared to the control group (p<0.01). Analysis of T-cell subsets revealed a significantly lower amount of CD8+ T-cells in patients with stable disease, leading to a significantly higher CD4/CD8 ratio in this group as compared to patients with active disease. Our study depicted an IL-2 deficiency in MS patients which is shared with other autoimmune diseases. In addition, our findings suggest that the ability to produce type-I IFNs, IFN-alpha and IFN-beta, is primarily impaired in MS patients and changes in correlation to the course of disease activity.

Adult↗
PubMed1997

Correlation between interferon production and clinical disease activity in patients with multiple sclerosis.

We determined the interferon (IFN) serum levels and in vitro activated IFN production in eight patients with relapsing/ remitting multiple sclerosis (MS), using a whole-blood test system and the mitogen concanavalin A and the viral antigen Newcastle disease virus for induction of the IFN production. During the overall study period of 12 months we observed, in relation to clinical disease progression, a biphasic increase in the individual IFN alpha and IFN gamma production. While mitogen-induced IFN gamma synthesis showed a significant augmentation prior to the onset of a new relapse (P < 0.05), virus-induced IFN alpha production showed a temporal delayed increase which was related to clinical remission (P < 0.01). The observed fluctuations in the individual production of both IFN subtypes were not reflected in the sera of the patients. Although the reason for the temporal different imbalance in the production of both IFN subtypes remains unknown, the observed association between increased IFN alpha production and clinical remission emphasizes a possible role for type 1 IFNs in the resolution of the MS relapse.

Adult↗
PubMed1997

Low efficiency of active immunization against diphtheria in chronic hemodialysis patients.

Recent epidemiological studies indicate a low immunity to diphtheria in adults in industrialized countries. In the light of the epidemic increase of diphtheria in countries such as Russia and the Ukraine, systematic vaccination against this disease is recommended. We analyzed the immunity to diphtheria of 228 hemodialysis patients and the efficiency of single versus triple vaccination against diphtheria. Antibodies against diphtheria toxoid were determined by enzyme immunoassay in sera of 228 adult hemodialysis patients. Fifty-four patients were triple vaccinated against diphtheria and were followed for six months; 17 patients were single immunized and antitoxoid titers were determined 1 and 12 months later. The overall protection rate against diphtheria was 22% and equal in male and female patients. After triple immunization, only 35% of the patients developed protective antibody concentration (> 0.1 i.e./ml) six months after the third vaccination. A single vaccination caused protective titres twelve months later in 41% of the patients. There was no difference between responders and non-responders in the duration, intensity or modality of hemodialysis treatment or the response to previous vaccinations against hepatitis-B. We suggest to monitor antibodies against diphtheria toxoid in vaccinated hemodialysis patients at risk for diphtheria since protective titers are often not attained by the standard vaccination protocol.

Adult↗
PubMed1997

The repertoire of HLA-Cw-specific NK cell receptors CD158 a/b (EB6 and GL183) in individuals with different HLA phenotypes.

Over the last few years, natural killer (NK) cells have been shown to express major histocompatibility complex (MHC) molecules recognizing receptors that are thought to function primarily as negative signalling receptors. Much attention has been focused on the NK cell receptors CD158a (EB6) and CD158b (GI 183), which recognize two alternative epitopes on the HLA-Cw locus. In order to investigate whether HLA type affects the CD158a/b repertoire, expressed as percentage positive cells for a particular receptor and mean expression on this population of NK cells, peripheral blood lymphocytes of 47 HLA-typed donors were examined. Peripheral blood samples were examined by flow cytometric analysis to investigate the expression of CD158a and CD158b receptors on the surface of NK cells. In parallel, we determined each individual's HLA phenotype. There was a great heterogeneity in CD158 expression; nevertheless all individuals had NK cells belonging either to the CD158 a+b-, a-b+ or a-b- populations. No positive or inverse correlations could be shown between either receptor expression intensity or proportion of positive cells, and presence of the appropriate ligand. Thus no association between an individual's NK receptor repertoire and HLA serotype could be demonstrated. It is concluded that CD158 is expressed on NK cells in a highly redundant fashion. Our data do not support either a positive selection mechanism or the receptor calibration model.

CD56 Antigen↗
PubMed1997

Impact of buffy coat storage on the generation of inflammatory cytokines and platelet activation.

BACKGROUND: Whole blood-derived buffy coat (BC) has become an alternative source from which to prepare random-donor platelet concentrates. The influence of prolonged storage of BC prior to platelet concentrate preparation is a matter of controversy. The impact of BC storage on cytokine release was evaluated and the platelet activation quantified. STUDY DESIGN AND METHODS: BCs were prepared from whole-blood donations after hard-spin centrifugation. After 1, 3, 6, 12, and 24 hours of storage at 22 degrees C without agitation, samples were withdrawn for cell count and blood gas analysis and measurement of interleukin (IL)-1beta, IL-6, IL-8, tumor necrosis factor alpha and platelet factor 4. Platelet surface markers CD41a, CD42b, CD62P, and CD63 were analyzed by flow cytometry, and the antibody-binding sites were quantified by using microbeads. RESULTS: Inflammatory cytokines IL-1beta, IL-6, and tumor necrosis factor alpha were hardly detectable in stored BCs but levels of IL-8 increased in 25 percent of BCs after 24 hours. A constant increase in platelet factor 4 was observed, which accelerated after 12 hours of storage. Analysis of platelet surface markers showed an initial decrease of platelet activation, followed by an increase after storage for 12 to 24 hours. CONCLUSION: Storage of BCs for up to 12 hours without agitation showed a good preservation of platelets but storage of BCs for 24 hours resulted in increased platelet activation and significantly higher release of platelet factor 4 and IL-8. Stored BCs might well be suitable for platelet preparation, but their storage time should not greatly exceed 12 hours.

Antibodies, Monoclonal↗
PubMed1997

Active specific immunotherapy of renal cell carcinoma: cellular and humoral immune responses.

We investigated the effect of vaccinating renal cell carcinoma (RCC) patients with irradiated autologous or allogeneic tumor cells and Newcastle disease virus (NDV) as adjuvant on cellular and humoral antitumor immunity. By Western blot analysis, we found that vaccination induced antibody formation in 33 of 34 patients against NDV proteins but not against tumor cell related antigens. NDV proteins detected had molecular weights of 53 kDa, 55-56 kDa, and 66 kDa. ADCC by patients' isolated PBMC and patients' sera against autologous or allogeneic tumor cells was not enhanced after vaccine treatment in a nonradioactive cytotoxicity assay. Target cells infected with NDV were lysed more effectively (p < 0.05) in ADCC after vaccination than noninfected targets. Natural cellular cytotoxicity of patients' isolated PBMC was not altered during vaccine treatment. Specific lysis rates against autologous and allogeneic RCC cells not exceeded 10% (effector:target ratio 50:1). Specific lysis of K-562 cells was > 20%; a slight decrease in lysis during vaccination was not significant. Numbers of lymphocyte subsets from patients' peripheral blood analyzed by FACS revealed significant expression of CD20+ (p < 0.02) and CD39+ (p < 0.03) cell numbers by vaccine therapy. Cytokine detection in patients' sera by ELISA showed significant increases (p < 0.05) for IFN-gamma and TNF-alpha but not for IFN-alpha four h post vaccination. Thus, immunomodulation with autologous or allogeneic RCC tumor cell vaccines is mainly due to cytokine induction, whereas tumor specific humoral or cellular responses are not detectable in patients' peripheral blood.

Antibody-Dependent Cell Cytotoxicity↗
PubMed1997

One-way synergistic effect of low superantigen concentrations on lipopolysaccharide-induced cytokine production.

Lipopolysaccharides (LPS) of gram-negative bacteria and superantigens of gram-positive bacteria are among the main causes of sepsis and septic shock. Symptoms are initiated primarily by the release of endogenous mediators, especially cytokines. In the last few years, increasing evidence for the clinical relevance of mixed sepsis caused by coinfections with both types of bacteria has been found. Therefore, we developed an in vitro mixed sepsis model investigating the effect of different superantigen doses, in combination with different LPS concentrations, on cytokine production in human PBMCs using ELISA and RT-PCR. Low, in vivo relevant concentrations of the superantigen toxic shock syndrome toxin-1 (TSST-1) synergistically enhance LPS-induced production of interferon-gamma (IFN-gamma) interleukin-1 beta (IL-1 beta), IL-6, and IL-10, but low LPS has no comparable effect. Signal transduction studies with different inhibitors suggest that this one-way synergism is caused by an interaction between the cAMP and the PIP2 signaling pathway. Furthermore, our findings support the idea that this interaction is one important crossover point of signal transduction pathways by LPS and superantigens, which seems to be predominantly regulated by IFN-gamma and PGE-2. The identification of additional crossover points in the genesis of a mixed sepsis and their selective influence could lead to identical treatment of both gram-negative and gram-positive sepsis.

Antigens, Bacterial↗
PubMed1997

Zinc supplementation reconstitutes the production of interferon-alpha by leukocytes from elderly persons.

The elderly are more prone to virus infections and neoplasias than are young adults. During a virus infection, interferon-alpha (IFN-alpha), proteins with antiviral, antiproliferative, and immunomodulatory properties, are transiently expressed. We here report that peripheral white blood cells from 16 subjects with a mean age of 72 years yielded less IFN when stimulated with a virus in vitro than those from 16 young adults with a mean age of 28 years. Monocytes are the main source of this IFN. However, yields of another monocyte product, interleukin-6 (IL-6), were greater in cells from the older subjects than from the young adults, so there is no general defect in monocytes from the former. Immunodeficiency in the elderly has been reported to be associated with a deficiency of zinc. When cultures of white blood cells from the elderly were supplemented with 15 microM zinc (the physiologic concentration), they produced IFN in amounts comparable to those from the younger subjects.

Adult↗
PubMed1997

Microbial superantigens stimulate T cells by the superantigen bridge and independently by a cytokine pathway.

Superantigens cross-link the MHC II molecule on accessory cells with the Vbeta region of the T cell receptor (TCR). In this study, we compared the capacity of established superantigens for inducing cytokine release. The experimental protocol was generated to answer the question whether all superantigen effects are transmitted by the MHC/TCR cross-linkage and induce mainly a T cell response. We found that TSST-1, ExFTA, and SEC3 differed from all other superantigens tested because they stimulated a stronger monokine release. T cell proliferation after challenge with these superantigens was mainly mediated by a cytokine pathway and not by the cross-linkage of MHC and TCR. For the other superantigens, we were able to demonstrate that major immunomodulatory effect is mediated by the superantigen bridge. With the exception of these three superantigens, the proliferative response of superantigens correlated with their Vbeta specificity. Interleukin-1 (IL-1) and IL-6 were induced in monocytes by all superantigens, whereas tumor necrosis factor-alpha (TNF-alpha) was induced in T cells and by some superantigens, also in monocytes. IL-2 was always induced by the superantigen bridge, whereas interferon-gamma (IFN-gamma) was also induced indirectly by monokines. Collectively, our results indicate that not all superantigens are suitable for investigating superantigen-specific effects, as they show indirect (mitogenic) side effects. Observations for an individual superantigen are, therefore, not transferable to all other superantigens.

Antigens, Bacterial↗
PubMed1997

Patients treated with interferon-alpha, interferon-beta, and interleukin-2 have a different thyroid autoantibody pattern than patients suffering from endogenous autoimmune thyroid disease.

Cytokines are believed to mediate the induction and perpetuation of autoimmune thyroid disease (ATD) in humans. However, this concept is mainly based on in vitro findings and to date, concrete in vivo evidence is still lacking. This prompted us to compare serum thyroid parameters of patients treated with cytokines with patients suffering from ATD. The cytokine group (n = 61) consisted of patients suffering from chronic hepatitis (n = 27) and from hemato-oncological diseases (n = 34). Patients were treated with interferon-alpha (IFN-alpha) or IFN-beta, either alone (n = 31) or in combination with interleukin-2 (IL-2) (n = 15) or with antineoplastic agents (n = 15). The ATD group (n = 105) consisted of 51 patients with Graves' disease, 26 with euthyroid ATD, 18 with Hashimoto's disease, and 10 with atrophic thyroiditis. Only 6 of 61 patients (10%) from the cytokine-treated group had thyroid peroxidase antibody (TPOAb) titers equal to or greater than 100 U/mL, whereas 82 of 87 patients (94%) suffering from ATD had TPOAb titers equal to or greater than 100 U/mL (p = 0.0001). In contrast, the percentage of patients who had thyroglobulin antibody (TgAb) serum titers equal to or greater than 100 U/mL were identical in both groups: 25 of 61 patients (41%) treated with cytokines versus 40 of 87 patients (46%) suffering from ATD (p = 0.789). Thus, patients with ATD had significantly higher TPOAb titers (p = 0.0001) whereas TgAb titers were not significantly different compared with patients from the cytokine group. The substantial difference in autoantibody response raises the possibility that thyroid abnormalities associated with ATD reflect genetic susceptibility and/or an independent stimulus or incident aside from cytokine dysfunction and that cytokines may play a secondary, rather than primary role in disease expression.

Adult↗
PubMed1997

ICAM-1, soluble-CD23, and interleukin-10 concentrations in serum in renal-transplant recipients with Epstein-Barr virus reactivation.

Primary and reactivated Epstein-Barr virus (EBV) infections after organ transplantation are associated with the development of posttransplant lymphoproliferative malignancies. Since viral reactivation frequently stays asymptomatic, early diagnosis and treatment are challenges during posttransplant patient monitoring. Both soluble-CD23 (sCD23) and intercellular adhesion molecule 1 (ICAM-1) cell surface expression as well as interleukin-10 (IL-10) production are closely associated with viral gene expression. Therefore, immunoglobulin M (IgM), IgG, IgA, sCD23, ICAM-1, and IL-10 concentrations were measured in serum samples from patients during EBV reactivation (n = 14) and were compared with those in samples from patients without EBV reactivation (n = 10) following renal transplantation. In addition, serum sCD23, ICAM-1, and IL-10 concentrations were measured longitudinally in weekly to biweekly samples from 10 patients with EBV reactivation for at least 20 weeks following transplantation. A significant elevation of sCD23 was found during viral reactivation (P < 0.05), whereas ICAM-1 levels showed a nonsignificant increase. The finding of a highly significant elevation of the serum IL-10 concentration during EBV reactivation (P < 0.001) may support speculations about its role in EBV-induced lymphoproliferation and in the development of opportunistic infections and secondary malignancies. Maximum serum IL-10 levels at the time of EBV reactivation were found in 7 of 10 patients. Well-defined ICAM-1 and sCD23 concentration peaks were found in 9 of 10 and 8 of 10 patients, respectively. Although both markers are not specific for EBV reactivation and therefore may not be useful for primary diagnosis, sCD23 and ICAM-1 might be potent tools for the clinical monitoring of EBV activity and virus-induced lymphoproliferation.

Antibodies, Viral↗
PubMed1997

Exclusion of bioactive contaminations in Streptococcus pyogenes erythrogenic toxin A preparations by recombinant expression in Escherichia coli.

The streptococcal erythrogenic exotoxin A (SPEA) belongs to the family of bacterial superantigens and has been implicated in the pathogenesis of a toxic shock-like syndrome and scarlet fever. Concerning its biological activity, mainly T-cell-stimulatory properties, conflicting data exist. In this study, we show that most of the SPEA preparations used so far contain biologically active contaminations. Natural SPEA from the culture supernatant of Streptococcus pyogenes NY-5 and recombinant SPEA purified from the culture filtrate of S. sanguis are strongly contaminated with DNases. We show that natural SPEA induces more tumor necrosis factor alpha (TNF-alpha) than recombinant SPEA, but we also show that DNases are able to induce TNF-alpha. In commercial SPEA preparations, we identified a highly active protease, which was shown not to be SPEB. To exclude these contaminations, we overexpressed SPEA cloned in the effective high-level expression vector pIN-III-ompA2 in Escherichia coli. The expressed SPEA shows the same amino acid composition as natural SPEA, whereas functional studies reported so far were carried out with toxins containing an incorrect amino terminus. We describe the rapid purification of lipopolysaccharide-, DNase-, and protease-free SPEA in two steps from the host's periplasm and its structural characterization by circular dichroism. Our results represent for the first time the production in E. coli of recombinant SPEA with the authentic N-terminal sequence and a proven superantigenic activity. Collectively, our results indicate that immunological studies of superantigens require highly purified substances free of biologically active contaminations.

Animals↗
PubMed1997

Dose-response relationship of complementary radiotherapy following four cycles of combination chemotherapy in intermediate-stage Hodgkin's disease.

PURPOSE: To determine the appropriate irradiation dose after four cycles of modern combination chemotherapy in nonbulky involved field (IF/BF) and noninvolved extended-field (EF/IF) sites in patients with intermediate-stage Hodgkin's disease (HD). MATERIALS AND METHODS: HD patients in stage I to IIIA with a large mediastinal mass, E stage, or massive spleen involvement were treated with two double cycles of alternating cyclophosphamide, vincristine, procarbazine, and prednisone (COPP) plus doxorubicin, bleomycin, vinblastine, and dacarbazine (ABVD) followed by EF irradiation in two successive trials (HD1 and HD5). In the HD1 trial (1983 to 1988), 146 patients who responded to chemotherapy were randomized to receive 20 Gy (70 patients) or 40 Gy (76 patients) of EF irradiation in all fields outside bulky disease sites. A cohort of 111 patients who fulfilled the same inclusion criteria in the subsequent trial HD5 (1988 to 1993) were treated with 30 Gy. Bulky disease always received 40 Gy. RESULTS: Freedom-from-treatment-failure (FFTF) and survival (SV) curves showed no differences between the 20-, 30-, and 40-Gy groups. However, acute toxicities were more frequent in the 40-Gy arm. Analysis of relapse patterns showed that 18 of 26 relapsing patients either failed to respond in initial bulky sites (n = 5) or had an extranodal relapse (n = 9) or both (n = 4). After 5 years, the cumulative risk for relapse in bulky sites is 10%, despite 40 Gy of radiation. CONCLUSION: Our results strongly suggest that there is no relevant radiotherapy dose effect in the range between 20 Gy and 40 Gy in IF/BF and EF/IF after 4 months of modern polychemotherapy in patients with intermediate-stage HD. Relapse patterns indicate that patients destined to relapse need more systemic, rather than local, treatment. Based on our data, we conclude that 20 Gy is sufficient in EF/IF of intermediate-stage HD following four cycles of modern polychemotherapy.

Adolescent↗
PubMed1997

[Cytokines and chemokines as inducers of nonhemolytic transfusion reactions after thrombocyte transfusion].

Recently, the leukocyte-derived cytokines interleukin (IL)-1 beta, IL-6, IL-8, and tumor necrosis factor(TNF)-alpha were found in considerable concentrations in platelet concentrates (PC) involved in nonhemolytic transfusion reactions (NHTR). We investigated transfusion reactions in two study periods over the last 3 years. In the 1st period, PC were leukocyte-depleted by bedside filtration. In the 2nd period we performed prestorage leukocyte filtration of PC. Recipients who experienced a transfusion reaction were tested for total and specific IgE, and reactions were analyzed with regard to the main symptoms. In the supernatant of platelets involved, we analyzed concentrations of IL-1 beta, IL-6, IL-8, TNF-alpha, macrophage inflammatory protein(MIP)-1 alpha, and RANTES. The incidence for NHTR did not change with the kind of PC transfused (n = 44, 1.63% and n = 46, 1.56%; p = 0.84), but allergic reactions were reduced in the 2nd observation period (0.92% versus 0.51%; p = 0.02). IL-1 beta, IL-6, IL-8, TNF-alpha, and MIP-1 alpha were not detectable in the majority of all products. PC involved in allergic reactions contained significantly higher concentrations of RANTES. We found evidence that the proinflammatory chemokine RANTES, stored in the platelet alpha-granules, is involved in allergic transfusion reactions. In contrast, leukocyte-derived inflammatory cytokines were of minor relevance in the onset of NHTR.

Blood Group Incompatibility↗