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Biomedical subjects

H Kirchner

Publications and source records attributed to H Kirchner.

At least 235 records · Page 13Linked to original sources
PubMed1992

Interferon and lymphokine production by human placental and cord blood cells.

The placenta plays an important role in protecting the fetus from maternal infections and in preventing an effective immune response of the mother against the fetus. We compared lymphokine production by human placental leukocytes with that of adult and cord blood leukocytes. Decidual and adult blood lymphocytes synthesized comparable quantities of interferon-gamma (IFN-gamma) following incubation with phytohemagglutinin (PHA). In contrast, lymphocytes of cord blood and fetal placental tissue stimulated with PHA produced very low titers of IFN-gamma. This defect was less marked after stimulation with staphylococcus enterotoxin B (SEB). In the presence of SEB, cord blood cells produced interleukin-2 (IL-2) and significant amounts of IFN-gamma. Production of IL-4 could not be detected. Collectively, these results indicate that fetal T lymphocytes show certain defects of lymphokine production.

Enzyme-Linked Immunosorbent Assay↗
PubMed1992

Deficiency in interferon production of peripheral blood leukocytes from patients with non-Hodgkin lymphoma.

In search for a rationale for the use of interferons (IFNs) in treatment of non-Hodgkin lymphoma (NHL), we have investigated the IFN system of 13 patients with low-grade NHL, 15 patients with high-grade NHL, and 20 patients with chronic lymphocytic leukemia or leukemic immunocytoma (CLL/IC). Production of IFN induced by phytohemagglutinin (PHA), concanavalin A (Con A), pokeweed mitogen (PWM), Corynebacterium parvum, Herpes simplex virus (HSV), Newcastle disease virus (NDV), and interleukin 2 (IL-2) were studied in the peripheral leukocytes from the patients and from 21 control persons by means of a whole blood technique. All three groups of patients with NHL had significantly reduced production upon stimulation by NDV (p ranged between 0.0038 and less than 0.0001) compared to controls. Similarly, C. parvum also induced lower titers of IFN in the leukocytes of patients with non-leukemic NHL (p = 0.0015 for low-grade NHL and p = 0.0038 for high-grade NHL). When stimulated by PHA, the IFN response of all groups of patients was within normal range. With the exception in low-grade NHL, Con A also induced normal titers of IFN in the patients with NHL. The levels of IFN induced by PWM, HSV, and IL-2 were very low and no differences between controls and patients could be found. As NDV and C. parvum induce mainly IFN-alpha and the mitogens PHA and Con A mainly IFN-gamma, our results suggest that there is a deficiency in the IFN-alpha response in the patients with NHL but normal response in IFN-gamma.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Prognostic factors for survival in patients with advanced renal cell carcinoma treated with recombinant interleukin-2.

A database of 327 patients with advanced Renal Cell Carcinoma (RCC) has been analyzed in order to identify potential baseline prognostic factors predicting for survival, following recombinant Interleukin-2 treatment (rIL-2). All patients received a continuous infusion (CIV). Eligibility criteria were uniform across studies, and included patients with an ambulatory performance status (PS), measurable disease, no CNS metastases, and no major organ compromise. Multivariate analyses identified baseline PS (ECOG 0 vs. 1), time from diagnosis to treatment (DTI greater than 24 months vs. less than or equal to 24 months), and the number of metastatic sites (1 vs. greater than or equal to 2, where lung, bone and other sites are considered as separate sites) as important predictors for survival. Patients can be classified into 4 subgroups, which are a function of the number of risk factors present. Median survival for each subgroup is 28, 17, 10 and 5 months, respectively. The model was validated in an independent cohort of 125 patients with RCC treated with subcutaneous (s/c) rIL-2, and predicted for survival accurately. By determining in which risk group category patients may fall, treating physicians may be better equipped to decide on patient management. The model may also be of value in order to stratify patients in randomized clinical trials.

Aged↗
PubMed1992

Rapid HLA-DRB1 genotyping by nested PCR amplification.

State of the art genotyping of HLA class II alleles with group-specific DNA amplification by the polymerase chain reaction (PCR) (1) and subsequent probing with sequence-specific oligonucleotides (2-4) is not suitable for typing cadaveric organ donors since the typing procedure takes far more than one working day. We designed specific oligonucleotide primer sets for nested PCR amplification which allowed typing for all serological HLA-DR specificities (DR1-DRw18) solely by the detection of amplified DNA in the reaction mixtures after agarose gel electrophoresis. Exon 2 of the DRB genes and a DRw52-group-specific part of DRB1 exon 2 was amplified directly from cell lysates without prior DNA extraction. The amplified DNA was subjected to a second round of amplification, which employed a set of 18 nested allele- or group-specific primer pairs. All alleles which have at least a single mismatched base at the terminal 3'-nucleotide of one primer were completely refractory to amplification. This assay is easy to perform and takes less than one working day to complete. Thus, this method may prove to be suitable for DNA typing of organ donors for prospective HLA-DR matching in renal transplantation.

Alleles↗
PubMed1992

Detection and quantification of latently infected B lymphocytes in Epstein-Barr virus-seropositive, healthy individuals by polymerase chain reaction.

We designed a highly sensitive and specific polymerase chain reaction assay for the detection of Epstein-Barr virus (EBV)-related sequences in B-cell DNA of EBV-seropositive healthy individuals. By using this assay, we were able to amplify at least 10 copies of a plasmid containing the BamHI-W region, which is repeated up to 11 times within the EBV genome, in the presence of 1 microgram of EBV-negative DNA, indicating that one virus genome was detectable from 150,000 cells. In 15 of 16 tested individuals, EBV-related sequences were found frequently when the DNA from 10(6) B lymphocytes was examined and 1 microgram of DNA was used in each polymerase chain reaction. When the results of amplifying the diluted plasmid were used as a semiquantitative standard, the number of EBV genomes detected could be estimated to range between 50 and less than 1 from 10(6) B lymphocytes. The results of our study will provide the basis for further investigations of the characteristics of the latent carrier state in healthy EBV-seropositive individuals, such as the determination of the number of virus copies per cell and expression of antigens.

Antibodies, Viral↗
PubMed1992

Pretreatment natural killer antigen density correlates to clinical response in tumor patients receiving long-term subcutaneous recombinant interleukin-2 and recombinant interferon-alpha.

We evaluated density of the natural killer (NK) cell-associated CD56 antigen on circulating NK cells of 47 patients with advanced renal cell carcinoma. Patients received a combination of low-dose subcutaneous recombinant interleukin-2 (rIL-2) and recombinant interferon-alpha (rIFN-alpha) as home therapy. Antigen density of CD56 before therapy was 2.2-fold higher (P < 0.005) in patients who subsequently achieved a complete or partial remission when compared with patients who presented with progressive disease on therapy. After a 6-week treatment cycle, NK cells of treatment responders expressed significantly (2.1-fold; P < 0.005) more CD56 antigens than NK cells in nonresponding patients. These results suggested a potential role of both pre- and posttreatment NK antigen density levels as a biologic correlate to treatment response.

Antigens, CD↗
PubMed1992

[Differentiation of leukocytes in thrombocyte concentrates by APAAP staining].

The preparation of platelet concentrates (PC) from pooled buffy coats has raised concern as to whether activation of lymphocytes might take place during the period of storage. Therefore it appears to be essential to investigate the degree of leukocyte contamination and identify the subtypes of these cells. Especially lymphocytes are of relevance as they may induce either a mixed lymphocyte reaction (MLR), the production of cytokines or a graft-versus-host reaction. As the number of leukocytes is very low we adopted the alkaline phosphatase-antialkaline phosphatase (APAAP) technique to determine the composition of leukocytes. We used mouse monoclonal antibodies to specifically stain T lymphocytes, B lymphocytes, monocytes, HLA-DR-positive cells and NK cells. All subtypes could easily be identified and their relative amounts were determined. In samples from 15 PCs the percentages of T lymphocytes, B lymphocytes, monocytes, NK cells and HLA-DR-positive cells was 40.3, 6.4, 18.9, 7.2 and 17.1% of total leukocytes, respectively. The standard deviation ranged between 2 and 5%. We highly recommend this technique, which is a very sensitive method to determine leukocyte contamination in PC.

B-Lymphocytes↗
PubMed1992

Biologic and therapeutic efficacy of mafosfamide in patients with metastatic renal cell carcinoma.

It is well known that oxazaphosphorines [e.g., cyclophosphamide and 4-hydroperoxycyclophosphamide (mafosfamide)] are potent immunosuppressive agents. Under the proper conditions, they can potentiate immune responses as well. Immunomodulation represents a major breakthrough in the management of chemotherapy-resistant tumors. Thus, we evaluated the clinical and laboratory sequelae of low to intermediate doses (100-1000 mg/m2) of mafosfamide administered to 16 patients. Four weeks after therapy, one patient had a complete remission, eight patients presented with stable disease, and seven patients did not respond. Clinical and laboratory toxicity was mild and totally reversible, and therapy was well tolerated in all patients. Analyses of phenotypic cell surface antigens on circulating peripheral blood mononuclear cells showed inconsistent alterations of the CD4/CD8 ratio, initial depletion with later rebound of CD8+ cells, increase of CD20+ cells, and a mafosfamide dose-dependent regulation of natural killer-like cells as characterized by CD16 and CD56 positivity. Cell-mediated cytotoxicity against K562 target cells peaked 1 day after therapy and was most pronounced in patients who had received 300 mg/m2 mafosfamide, whereas cytotoxicity against Daudi targets was essentially unchanged, consistent with an increase in natural killing activity without augmentation of lymphokine activated killing. We conclude that mafosfamide administration at low to intermediate doses can be performed with good safety and tolerance; immunophenotypic analyses and cytotoxicity assays showed most pronounced alterations in patients receiving low doses of mafosfamide. These observations support the use of mafosfamide in the attempt to augment antitumor immune responses.

Adjuvants, Immunologic↗
PubMed1992

Induction of cytokines in human peripheral blood and spleen cells by the Mycoplasma arthritidis-derived superantigen.

Recently, the mitogenic effects of the Mycoplasma arthritidis supernatant, MAS, and the induction of interferon-gamma (IFN-gamma) and interleukin-6 (IL-6) by MAS have been described. In the present series of experiments we investigated human peripheral blood mononuclear cells (PBM) and human spleen cells with respect to their production of these and other cytokines. In human spleen cell cultures and PBM, MAS induced the synthesis of interleukin-1 alpha (IL-1 alpha) and IL-1 beta. Both interleukins were secreted faster and in higher amounts by PBM. IL-6 was also induced by MAS in PBM and human spleen cells. The amounts of IL-6 measured by ELISA were higher in PBM, whereas the biological activity of IL-6 was higher in spleen cell cultures. T-cell products such as IL-2, IL-4, and IFN-gamma were also induced by MAS in PBM and spleen cells. The kinetics of IFN-gamma and IL-4 induction were negatively correlated. In PBM we found low levels of IL-4 and high IFN-gamma induction, whereas in spleen cells high titers of IL-4 and low IFN-gamma titers were observed. Collectively, our results indicate that MAS induces different networks of cytokine interactions depending on the organ from which the cells are derived.

Antigens↗
PubMed1991

Biological monitoring of low-dose interleukin 2 in humans: soluble interleukin 2 receptors, cytokines, and cell surface phenotypes.

Different immunotherapy regimens using s.c. recombinant interleukin-2 (rIL-2) were studied in 76 patients with progressive metastatic renal carcinoma, malignant melanoma, colorectal cancer, B-cell lymphoma, or Hodgkin's disease. To assess the immunomodulatory capacity of rIL-2, we measured serum levels of soluble interleukin-2 (sIL-2) receptors, gamma-interferon, tumor necrosis factor-alpha, and various lymphocyte subsets expressing the CD25 Tac IL-2 receptor and the CD56 natural killer (NK) associated antigen. Additionally, we measured serum antibodies specific to rIL-2 in order to evaluate immunogenicity of rIL-2. In all patients, a significant increase in sIL-2 receptor levels could be observed when comparing values on day 0 and after one treatment course. Patients developing a neutralizing anti-rIL-2 antibody exhibited significantly lower serum sIL-2 receptor levels than patients without antibody. Soluble IL-2 receptors correlated with the percentage of CD25 IL-2 receptor-positive peripheral blood lymphocytes. Both soluble and cell surface IL-2 receptors exhibited a significant increase during rIL-2 therapy but did not correlate with the percentage of CD56-positive peripheral blood lymphocytes. Measurement of treatment-induced secondary cytokines showed significant increases in gamma-interferon serum levels in a proportion of patients tested, although with considerable interindividual variability. No significant increase in mean tumor necrosis factor-alpha levels was observed during rIL-2 treatment in vivo. The percentage of CD56-positive NK cells correlated with the clinical outcome of rIL-2 therapy. Thus, partial or complete responders had an increase from a mean of 20% NK cells prior to therapy up to a mean of 40% after the first treatment course. In contrast, patients with progressive disease had a mean of 22 and 24% NK cells before and after treatment, respectively.

Carcinoma, Renal Cell↗
PubMed1991

The development of neutralizing antibodies in a patient receiving subcutaneous recombinant and natural interleukin-2.

Systemic administration of interleukin-2 (IL-2) in humans may induce antibodies specific to IL-2. The case is reported of a patient with metastatic rectal carcinoma who was treated with long-term subcutaneous IL-2 and a combination of subcutaneous IL-2 and interferon-alpha 2b (IFN-alpha 2b). This patient developed nonneutralizing and neutralizing anti-IL-2 antibodies recognizing both the recombinant and natural cytokine. Detectable serum levels of neutralizing antibodies were accompanied by the inhibition of immune responsiveness to systemic IL-2 in vivo.

Antibodies↗
PubMed1991

The detection of human cytomegalovirus immediate early antigen in peripheral blood leucocytes.

Recently, Van der Bij et al. (1988) reported that active human cytomegalovirus (HCMV) infection could be diagnosed by the detection of HCMV immediate early antigen (IEA) directly in the peripheral blood leucocytes of renal transplant recipients. However, the indirect peroxidase technique used resulted in high background staining due to endogenous peroxidase activity and thus the detection of HCMV-IEA positive leucocytes, which are sometimes present in extremely low numbers, was not always reliable. In an attempt to solve this problem, we have evaluated the alkaline phosphatase-anti-alkaline phosphatase (APAAP) technique, immunogold-silver staining (IGSS), and several fixatives. Fixation with acetone: methanol 1:1 in conjunction with the APAAP technique proved to be the most successful method. In 155 blood samples obtained from 44 patients following renal transplantation and from three AIDS patients, the number of positive cells ranged between 1 and 700 out of 400,000 (median 2). In 23 samples from 11 patients (one AIDS patient) at least one positive cell was found. In this series there were no problems with the evaluation since strong positive signals were obtained without any background staining. We therefore recommend the use of this protocol for the rapid and reliable detection of HCMV-IEA in peripheral blood leucocytes.

Acquired Immunodeficiency Syndrome↗
PubMed1991

The out-patient use of recombinant human interleukin-2 and interferon alfa-2b in advanced malignancies.

We studied the safety, tolerance, and clinical effects of the combined administration of subcutaneous recombinant human interleukin-2 and interferon alfa-2b in 54 patients with advanced cancer, for whom no effective standard therapy was available. Treatment courses consisted of a 2-day interleukin-2 pulse (14.4-18 million units (MU) m2/day), followed by 3.6 up to 4.8 MU/m2/day, 5 days per week, over 6 consecutive weeks and interferon alfa-2b at 3 up to 6 MU/m2, administered two-three times weekly for 6 weeks. Overall, patients received more than 90% of the projected dose of interleukin-2 and interferon alfa-2b, respectively. Of 54 evaluable patients (32 renal cell cancer, 12 melanoma, eight colorectal cancer, one B-cell lymphoma, one Hodgkin's disease), four complete responses occurred in patients with renal cell carcinoma, and a greater than 50% reduction in tumour size (partial response) in six renal cell carcinoma patients and one melanoma patient. Moreover, 21 patients (13 renal carcinoma) had stable disease. The median duration of response was 19 months (range 16-22 months) in complete responders. Clinical responses were associated with a mean peripheral blood eosinophil count of more than 1,000/microL (P less than 0.05 versus non-responders). Systemic toxicities included fever, chills, nausea, anorexia, and hypotension limited to WHO grades I and II in more than 80% of patients treated. No treatment-related deaths occurred. This combination of subcutaneously administered recombinant interleukin-2 and interferon alfa-2b has significantly diminished the side effects normally observed with high-dose intravenous recombinant interleukin-2, which requires admission to hospital. It has been shown to induce objective tumour regression in out-patients with progressive metastatic renal cell carcinoma and malignant melanoma.

Adult↗
PubMed1991

In situ hybridization of interferon-gamma producing peripheral blood mononuclear cells.

Individual interferon-gamma (IFN-gamma) producing cells in activated human peripheral blood mononuclear cells (PBMC) were characterized by in situ hybridization using [35S]-labelled antisense RNA probes. The proportion of positive cells expressing IFN-gamma mRNA varied according to the substances used for stimulation. IFN-gamma mRNA expressed a relatively low percentage of 1-8% PBMC after a single stimulus with mitogens or OKT-3 antibody and 20-30% of the cells were identified to synthesize IFN-gamma mRNA after stimulation with PHA + P-MA + OKT-3 antibody. The expression of IFN-gamma mRNA and production of the lymphokine was dependent on accessory cells. If accessory cells were replaced by recombinant interleukin-1 (IL-1) plus interleukin-6 (IL-6), then T-cell proliferation to phytohaemagglutinin (PHA) could be partially restored and measurable amounts of IFN-gamma were detected. The addition of interleukin-2 (IL-2) or phorbol-12-myristate-13-acetate to T cells stimulated with PHA, IL-1 and IL-6 did not restore the production of IFN-gamma to an extent comparable to that produced by T cells stimulated in the presence of accessory cells. In further studies, depletion of T-cell subsets showed that CD3+, CD4+, CD8+, CD29+ and CD45RA+ cells were involved in IFN-gamma production after mitogenic stimulation. In conclusion, our data demonstrate that IFN-gamma production is dependent on signals from accessory cells and IFN-gamma is synthesized by only a small proportion of T cells, that did not belong to a unique population, characterized by conventional cellular surface antigens.

Blotting, Northern↗
PubMed1991

[Ligament lesions of the subtalar joint].

Emphasis of the article is on the chronic instabilities in the ankle joint and the talocalcaneonavicular joint. The diagnosis of these lesions is demonstrated. An easy to perform technique of x-ray film to prove chronic instability in the talocalcaneonavicular joint is presented. Assessment of luxatio pedis sub talo and of the total dislocation of the talus with its associated lesions is performed with the help of a review of the literature and a description of 12 patients examined by the authors.

Ankle Injuries↗
PubMed1991

Diminished expression of interleukin-2 receptors in vivo after prior chemotherapy in advanced cancer patients receiving recombinant interleukin-2.

In a phase I/II dose escalation study performed at our institution, a total of 14 advanced metastatic cancer patients received between 4 and 16 weeks of subcutaneous recombinant interleukin-2. Doses were escalated at weekly intervals, starting at 1.8 million IU/m2/day up to a maximum dose of 14.4 million U/m2 daily. When comparing patients with (n = 4) and without (n = 7) prior chemotherapy on day 0 (i.e., before rIL-2), both patient groups exhibited Tac IL-2 receptor (CD25) positive peripheral blood lymphocytes at equal levels of positivity (8%). In contrast, 4-week systemic treatment with subcutaneous rIL-2 at escalating dose levels revealed a significant difference in the up-regulation by interleukin-2 of CD25 cell surface receptor. Thus, after 4 consecutive weeks of treatment, patients without previous chemotherapy showed a mean CD25 positivity of peripheral blood lymphocytes at 38%, as compared with 22% in patients who did receive prior chemotherapy (p less than 0.05). These data suggest that chemotherapy pretreatment may have a significant effect on biological response to rIL-2 in vivo.

Antineoplastic Combined Chemotherapy Protocols↗