Biomedical subjects

H Rühl

Publications and source records attributed to H Rühl.

At least 37 records · Page 2Linked to original sources

PubMed1984

[Disorders of B cell activation in splenectomized patients].

Using a reverse hemolytic plaque assay as the effector system, we studied in vitro B-lymphocyte function in 12 patients after posttraumatic splenectomy as well as in 25 normal individuals. The time interval between the splenectomy and the immunological studies varied between 2 days and 7 years. Compared to normal individuals, the splenectomized patients had markedly elevated numbers of spontaneous immunoglobulin-secreting cells and severely decreased responses to the polyclonal activator pokeweed mitogen, indicating an in vivo polyclonal B-cell activation. A tendency towards normalization of these abnormalities, especially the high spontaneous ISC levels, could be observed during the time interval extending up to 7 years after splenectomy. In order to characterize the mechanism responsible for the altered immune response in splenectomized patients, in vitro experiments were performed with separated lymphocytes. These revealed an impaired T-helper cell capacity as well as an intrinsic B-cell defect. Marker analysis with monoclonal antibodies revealed normal proportions with the exception of OKT 4 positive and B 1 positive cells that identify T-helper/inducer and peripheral B-cells, respectively. We conclude that immune dysfunction in peripheral blood lymphocytes of splenectomized patients involves mainly the OKT 4 positive cell population.

Adult↗

PubMed1984

Ph1 positive blast crisis of chronic myeloid leukaemia exhibiting features characteristic of early T blasts.

Leukaemic cells from a patient in the blast crisis of chronic myeloid leukaemia were subjected to a surface marker analysis using a panel of monoclonal antibodies recognizing differentiation antigens of myeloid (MY7, MY906, VIM D5, M phi P9), erythroid (VIE G4), megakaryocyte (AN51), T-lymphoid (WT1, 10.2, OKT3, OKT4, OKT6, OKT8, OKT11A) and B-lymphoid cells (B1, B2, Y29/55), common ALL-antigen (VILA1), non-lineage-restricted antigens (OKT9, OKT10), monomorphic HLA-DR determinants (7.2) as well as TdT. When the patient entered his first blast crisis, his blasts expressed a phenotype corresponding to an immature myeloid cell (7.2+, MY7+, My906+, VIM D5-). Ph1-chromosome-positive blasts from this patient's first relapse had completely changed their surface marker characteristics: they had become TdT-positive and exhibited surface features characteristic of early T blasts (WT1+, 10.2+, OKT9+, OKT10+, 7.2-, OKT6-). Together, these features provide evidence that myeloid cells may share a common precursor with T cells.

Adult↗

PubMed1984

p69,71 antigen complex detected by monoclonal antibody Leu 1 in the identification of particular stages of malignant B-cell differentiation.

Lymphomatous cell samples from 86 patients with B-cell neoplasia (34 chronic lymphocytic leukaemia, 8 hairy-cell leukaemia, 5 prolymphocytic leukaemia, 20 immunocytic lymphoma, 9 centrocytic lymphoma, 3 centroblastic/centrocytic lymphoma, 3 lymphoblastic lymphoma, 1 plasma cell leukaemia and 3 plasmacytoma) were studied using the monoclonal antibody Leu 1, detecting a p69,71 antigen complex present on nearly all thymocytes, most (greater than 85%) peripheral T-lymphocytes as well as some malignant B-cells. Furthermore, we compared the reactivity of Leu 1-positive B-cells with those exhibiting conventional surface markers such as mouse-erythrocyte-receptor, FcIgG-receptor, C3b- or C3d-receptor and surface immunoglobulins of the various heavy- and light-chain types. Our results demonstrate a correlation between the expression of p69,71 antigen complex and distinct phenotypes revealed by conventional markers and underline the value of Leu 1 monoclonal antibody in the differential diagnosis of human B-cell neoplasia.

Antibodies, Monoclonal↗

PubMed1984

Abnormalities of B-cell activation and immunoregulation in patients with Crohn's disease.

We have studied B-lymphocyte function in 39 patients with Crohn's disease and 35 normal individuals using a reverse haemolytic plaque assay as the effector system. Ten patients had active Crohn's disease, the others being in an inactive state of the disease. Compared with normal individuals, the Crohn's disease patients - especially those in the active state of the disease - had markedly raised numbers of spontaneous immunoglobulin secreting cells and severely decreased responses to the polyclonal activator pokeweed mitogen. The differences between the reactivity of patients with active disease and those with inactive disease were statistically significant. These findings indicate an in vivo polyclonal B-cell activation in Crohn's disease patients, possibly due to antigen(s) or infectious agent(s). In vitro experiments were performed with separated lymphocytes in order to characterise the mechanism responsible for the altered immune reactivity in Crohn's disease. These revealed an intrinsic B-cell defect as well as an impaired T-helper cell capacity in patients with Crohn's disease. Findings supporting the hypothesis of an increased suppressor activity in Crohn's disease patients could not be observed, and marker analyses revealed normal proportions with the exception of raised Leu 7 positive cells that mediate 'natural killer' and 'killer' cytolysis. We conclude that immune dysfunction in peripheral blood lymphocytes of Crohn's disease patients involves B-cells as well as T-helper cells.

Adult↗

PubMed1984

T-ALL related to intermediate cortical/medullary thymocytes displaying functional and surface characteristics of suppressor T cells.

Leukemic cells of a patient with acute T-lymphoblastic leukemia (T-ALL) exhibiting the uncommon clinical feature of hypogammaglobulinemia were examined in terms of surface markers and immunologic functions. Employing various monoclonal reagents reacting with surface antigens present on T cells and additional conventional markers, it was shown that the patient's leukemic cells expressed a phenotypical profile (E-R+, TdT+, C3d-R-, OKT3-, T4-, T6(+), T 10+, T8++) corresponding to the intermediate stage between the cortical and medullary phase of normal thymocyte differentiation. Functionally, they were unable to respond to mitogens or to produce detectable amounts of immunoglobulins or to provide 'help' for allogeneic antibody production while they suppressed the immunoglobulin production of normal B cells by 76% in coculture experiments.

Adult↗

PubMed1983

Heterogeneity of T-cell neoplasias as defined by monoclonal antibodies.

Surface marker studies were carried out on neoplastic cell samples (peripheral aspirates and skin biopsies) of 302 patients with non-Hodgkin lymphomas (221 patients) and acute lymphatic leukaemias (81 patients). In 11 patients with non-Hodgkin lymphomas (5%) and eight patients with acute lymphatic leukaemia (10%), the neoplastic cells possessed phenotypic characteristics of T cells. The investigations were carried out by means of an indirect immunofluorescence technique using a panel of monoclonal antibodies (OKT 3, 4, 6, 8, 9, 10; OKM 1; HNK 1 and VIL A 1). In addition, conventional markers (SIg, E-R 4 degrees, E-R 37 degrees, absorbed polyclonal rabbit antithymus and anti-TDT) were used. Our results, which show a pronounced phenotypic surface marker heterogeneity between the group of T-cell neoplasias, emphasize the diagnostic value of monoclonal antisera as compared to polyclonal reagents. Eleven different surface marker profiles were observed in the 19 patients investigated.

Adult↗

PubMed1983

Lymphocyte subsets in the peripheral blood of patients with multiple myeloma and benign monoclonal gammopathy.

A panel of monoclonal antibodies that identify various antigens present on T and B cells was used to characterize circulating blood lymphocyte subsets in multiple myeloma [(MM)--13 patients] and benign monoclonal gammopathy [(BMG)--5 patients]. In MM and BMG an increase in B cell proportions (BA 1 positive cells) was observed, whereas T cells (Lyt 3 positive cells) were reduced compared to normal controls. However, with respect to the T cell subset distribution, a marked diversity between MM and BMG was noted. This may help to differentiate BMG from MM. In MM a relative decrease in inducer/helper T cells (OKT 4 positive cells) and increase in suppressor/cytotoxic T cells (OKT 8 positive cells) as well as in NK/K T cells (Leu 7 positive cells) was observed. On the other hand, in BMG the relative T cell subset distribution was comparable to those seen in normal subjects.

Adult↗

PubMed1983

Evaluation of the circulating and splenic lymphocyte subpopulations in patients with non-Hodgkin lymphomas and Hodgkin's disease using monoclonal antibodies.

The number of B lymphocytes, T lymphocytes and their helper/inducer, cytotoxic/suppressor and NK/K subpopulations was measured in peripheral blood and spleen cell suspensions from patients with Hodgkin's disease (HD) in the active stage of the disease and in remission status, as well as in Non-Hodgkin lymphomas (NHL) in active stage of the disease. B lymphocytes were determined by direct immunofluorescence and T lymphocytes with the E rosette technique. Helper/inducer, cytotoxic/suppressor, and NK/K T lymphocytes were determined by indirect immunofluorescence with the monoclonal antibodies OKT4, OKT8 and Leu 7 (HNK1). In the same way, Lyt3 was used for determination of the total T lymphocytes. Whereas in peripheral blood of the NHL group an increase of B lymphocytes and a slight reduction of T lymphocytes could be observed, with normal distribution of the subpopulations, in patients with active HD as well as in those in remission, a marked absolute and relative decrease of T helper/inducer cells was found with normal cytotoxic/suppressor and NK/K proportion. In contrast to this, a significant increase of helper/inducer T lymphocytes with decreased cytotoxic/suppressor T proportion was found in spleen cell suspensions of patients with HD.

Adult↗

PubMed1983

Expanded T gamma cell populations with the morphology of large granular lymphocytes -- I. Immunological, clinical and morphological characterization.

Lymphocytes from two patients with T gamma cell proliferations displaying the morphology of large granular lymphocytes (LGL) were characterized in terms of cell marker phenotyping and immunologic functions. In both patients, the lymphocytes were positive for E-R, HuTLA, OKT5, OKT8, OKT11, OKM1, VEP13, Leu1, Leu2a, Lyt2 and Lyt3 and were negative for Tmu, Tar, SIg, BA1, BA2, EM-R, C3d-R, C3b-R, OKT6, OKT9, Leu3a, OKIa1 and TdT. In addition, investigations for T411, T811 and M522 in patient 1 yielded positive results. There were differences in the phenotype of the two patients with regard to the reactions with OKT3, OKT10 and VEP10. While, in patient 1, OKT3 was very pronounced and OKT10 and VEP10 were completely negative, OKT10 and VEP10 were very pronounced in patient 2, whereas OKT3 was positive only in a very small percentage of cells. Though the lymphocytes in both patients were potent effectors of NK and K functions (patient 2 more strongly than patient 1) and a noticeably reduced mitogen response was shown to PHA, Con A and zinc, patient 1 showed a distinct suppression of allogenic and autologous B cell response to transformation into ISC, coinciding with the clinical observation of a hypogammaglobulinemia; neither B cell suppression nor dysgammaglobulinemia was seen in patient 2. The results are discussed with regard to other comparable T gamma proliferations reported in the literature.

Aged↗

PubMed1983

Dual expression of T and B cell markers in human B cell neoplasias.

Macrophage- and T-cell-depleted mononuclear cells from 36 patients with B cell lymphoma and 12 healthy individuals were investigated by indirect immunofluorescence with the monoclonal antibodies NEI-011 (7.2) and NEI-015 (10.2). The monoclonal antibody NEI-011 (7.2) recognized the Ia antigen and identified almost all B cells in the peripheral blood of healthy individuals. Furthermore, neoplastic B cells from all patients except those with plasma cell proliferation were found to react with this antibody. NEI-015 (10.2), a monoclonal antibody known to react with both T cells and B-CLL cells, did not react with normal circulating B cells. However, this antibody did identify neoplastic B cells except in cases of plasma cell proliferation and lymphoblastic lymphoma.

Antibodies, Monoclonal↗

PubMed1983

Further evidence for T cell abnormalities in chronic lymphocytic leukaemia of the B cell type.

Functional properties were studied in the purified T cell fraction of patients with chronic lymphocytic leukaemia of the B cell type (B-CLL). This analysis included the evaluation of T suppressor activity when investigated patients' T cells were co-cultured together with allogenic normal B and OKT4 enriched T cells in the presence of pokeweed mitogen (PWM). The Ig secreting cells (ISC) were assessed in a reverse haemolytic plaque assay (RHPA). Antibody-dependent cytotoxicity (ADCC) and natural killer activity (NK) were determined in a 51Cr release assay. Furthermore, purified T cells reactive with the monoclonal antibody HNK1, known to recognize most effector cells in ADCC and NK, were enumerated using an indirect immunofluorescence. Our results revealed increased T suppressor cell activity and markedly deficient NK activity in peripheral blood lymphocytes (PBL), T cell and T gamma cell fractions from B-CLL patients, whereas ADCC potential was only increased in T cells and T gamma cells. Accordingly, T cells were recognized by HNK1 in greater numbers in B-CLL patients than in healthy subjects. Our data suggest that there may be a link between our findings and the hypogammaglobulinaemia as well as the increased incidence of second neoplasias reported in CLL.

Aged↗

PubMed1982

B-cell function in patients with chronic lymphocytic leukemia.

Using a reverse hemolytic protein A plaque assay, spontaneous and pokeweed mitogen (PWM)-induced immunoglobulin (Ig) secretion was determined in peripheral blood from 22 patients with B1-chronic lymphocytic leukemia (CLL), one patient with B2-CLL, and one patient with suppressor T-CLL. Diagnoses were established by cytological and histological criteria as well as several marker analyses. Lymphocytes from B1- and B2-CLL patients were unable to secrete Ig either spontaneously or after PWM stimulation. In T-CLL lymphocytes, spontaneous Ig secretion was suppressed very probably by the OKT-8-positive leukemic population, since, after cultivation with PWM, a normal Ig secretion could be demonstrated which was paralleled by a decrease in the OKT-8-positive cells. Cocultivation experiments with freshly isolated, unseparated lymphocytes from normal subjects and lymphocytes from patients were of no informational value, since isolated normal B-cells alone already showed a high rate of Ig secretion. However, coculture experiments with separated subpopulations after PWM stimulation revealed an intrinsic B-cell defect in lymphocytes from B1-CLL patients, whereas their T-lymphocytes were found to be normal helper cells.

Adult↗

PubMed1982

Multicentre study on intensified remission induction therapy for acute myeloid leukemia.

In a cooperative study at 13 centres in the Federal Republic of Germany, 213 adult patients with AML were treated for remission induction by a 9-day regimen consisting of cytosine arabinoside, daunorubicin and thioguanine (TAD) according to previously described sequencing. Complete remission was achieved in 70% of all patients. Complete remission rate was 57% in the 49 patients 60 years of age and older and 74% in the 164 patients under 60 years. Sixty-eight per cent of all complete remissions and 75% of those in the higher age group were induced by one induction course. Median survival was 10 months for all patients treated and 16 months for responders. Median remission duration was 13 months with 72 patients still in continuous remission for 1-31 months. Remission duration was not significantly different for patients treated either by monthly maintenance therapy or induction type consolidation without further therapy. However, patients completing two consolidation courses had a significantly longer remission duration of 22 months. Compared to similar multicentre studies on AML therapy the intensified induction regimen applied in this study shows an improvement even in older patients.

Adolescent↗

PubMed1982

Imbalance of T cell subpopulations in patients with chronic lymphocytic leukaemia of the B cell type.

T cell enriched mononuclear cells from the peripheral blood of 20 patients with histologically and immunologically defined chronic lymphocytic leukaemia of the B cell type (B-CLL) and 20 healthy individuals of various ages were investigated with T cell-specific monoclonal antibodies (OKT 4 and OKT 8) with regard to their subpopulation distribution. In B-CLL, a significant increase of lymphocytes reacting with OKT 8 could be demonstrated. Whereas there was a ratio of OKT 4 to OKT 8 of 1 X 72 in the control group, an OKT 4 to OKT 8 ratio of 0 X 67 was found in the B-CLL as a whole. With increasing clinical stage in accordance with the Rai scheme (Rai et al., 1975), a further displacement of this ratio in favour of OKT 8 positive cells was found. These results clearly show that, in peripheral blood of patients with B-CLL, an abnormal distribution pattern of circulating T cell subpopulations is present and that this also has prognostic relevance.

Antibodies, Monoclonal↗

PubMed1981

Adjuvant specific immunotherapy in maintenance treatment of adult acute non-lymphocytic leukemia.

From 1976 until 1978, 136 adult patients with acute leukemia were treated in four hospitals in Berlin. A complete remission was achieved in 47 patients (35%). Twenty-six patients with non-lymphocytic acute leukemia, who had achieved a complete remission with induction chemotherapy consisting of daunorubicin (45 mg/m2/day, day 1, 2 and 3) and cytosine-arabinoside (100 mg/m2/day, continuous infusion, day 1 to day 7) were entered into a randomized trial. Thirteen patients were treated with an intermittent combination chemotherapy at 4-week intervals; the other group of patients received in addition a specific immunotherapy consisting of neuraminidase-modified allogeneic blast cells. The results revealed that the addition of this kind of immunotherapy did not increase the duration of first remission or survival.

Adolescent↗

PubMed1981

PWM-induced generation of immunoglobulin-secreting cells in patients with multiple myeloma.

The pokeweed-mitogen-induced transformation of B-lymphocytes into immunoglobulin-secreting cells was studied in vitro in 25 patients with multiple myeloma using a reverse hemolytic plaque assay. Fifteen patients showed a good response in generating immunoglobulin-secreting cells, whereas 10 patients showed a decreased B cell reactivity which was not due to intermittent melphalan/steroid therapy administered to 15 patients. Experiments with lymphocyte subpopulations demonstrated that the inability of some multiple-myeloma patients to generate immunoglobulin-secreting cells was always based on a defect in the B-cell subset. Co-culture experiments with lymphocytes from normal individuals and patients revealed a cell-mediated suppression in one case, whereas humoral suppressive factors in the patients' serum could not be observed using the reverse hemolytic plaque assay. Patients were classified into three groups: (a) patients with a normal B-cell function, (b) patients with a reversible, tumor-dependent suppression of B-cell reactivity and (c) patients in whom the normal B-cell population was replaced by non-reactive cells.

Adult↗

PubMed1981

Impaired B-lymphocyte reactivity in patients with Hodgkin's disease and non-Hodgkin-lymphomas.

The generation of immunoglobulin-secreting cells upon stimulation with pokeweed mitogen was studied in patients with Hodgkin's Disease (HD) and non-Hodgkin lymphomas (NHL) using a reverse hemolytic plaque assay. The experiments revealed that the majority of the patients in both groups had greatly diminished responses of their peripheral B-lymphocytes. Whereas in NHL patients an intrinsic B-cell defect is the most likely explanation for the impaired B-cell reactivity, the situation in HD appears to be more complex. In some patients with an active stage of the disease, suppressor cells were found to cause the unresponsiveness: in other patients, an intrinsic B-cell defect as well as a defect of the T helper cells were responsible for the diminished responses. The results further suggest that the immune defect in patients with HD is reversible and can be corrected by therapy.

Adolescent↗

PubMed1980

Characteristics of immunoglobulin secretion in man evaluated by a reverse hemolytic plaque assay.

The kinetics of Pokeweed mitogen-induced transformation of human B-lymphocytes into immunoglobulin-secreting cells were examined in a reverse hemolytic plaque assay using protein A-coated sheep red blood cells as indicator cells. Peak responses occurred consistently after 6-8 days of incubation. After determination of the optimal experimental conditions the RHPA was found to be a reliable tool to estimate ISC in vitro; the technique was also found to be applicable for experiments surveying the B-cell response of an individual over a period of months. The PWM-induced transformation of B cells was absolutely T-cell-dependent. Other substances known as typical T-cell mitogens were also tested for polyclonal B-cell activation and some of them showed significant responses. Further experiments have shown that co-cultivation of non-HLA identical cells did not increase the number of plaques in unstimulated cultures whereas the addition of PWM leads to the generation of ISC within the expected range. These findings open a wide field of application of the RHPA in experimental and clinical immunology.

Animals↗