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

Modulation of immune functions by long-term treatment with recombinant interferon-alpha 2 in a patient with hairy-cell leukemia

Serial in vitro immune function studies of peripheral blood mononuclear cells (PBMC) were carried out during the long-term treatment with recombinant interferon-alpha 2 (IFN-alpha 2) in a patient with hairy-cell leukemia (HCL). Parameters of B- and T-cell functions as well as NK-cell activity were determined. Treatment with IFN-alpha 2 is associated with temporary and long-term depression of some immune functions, but can also normalize immune responses: in vitro-induced immunoglobulin synthesis, which was normal at diagnosis, was inhibited during the first weeks of IFN therapy but subsequently rose to normal levels. Lymphocyte proliferative responses to mitogens and antigens that were markedly reduced pretherapeutically were further depressed by IFN treatment but, with the exception of pokeweed mitogen (PWM)-induced responses, normalized completely by the 15th to 17th week of treatment. Cocultivation of PBMC with monocytes from normal individuals enhanced depressed lymphocyte proliferative responses. NK-cell activity, which was low at diagnosis, did not rise to the normal range during IFN treatment, but rapidly normalized when IFN therapy was stopped. A discussion is presented on the implications of the alteration of immune functions by treatment with IFN.

Chronic myelocytic leukemia as a second neoplasia in the course of chronic lymphocytic leukemia. Case report and review of the literature

A patient with chronic lymphocytic leukemia developed Ph1-positive chronic myelocytic leukemia after a 6-yr course of CLL. Chemotherapy for CLL consisted of chlorambucil and steroids, later vincristine and bleomycin; after resistance to these agents, cyclophosphamide, vincristine and prednisolone were applied. When CML was diagnosed, we found two morphologically distinct populations of malignant cells in the bone marrow; the Ph1-chromosome was identified, and immunological surface marker studies also demonstrated two distinct malignant cell populations. Up to now, only five cases of CML have been reported following CLL and one case accompanying it. Three patients were treated with cytostatic drugs, one patient by total body irradiation and two patients received no therapy. At present, it is not clear whether the development of CML during CLL represents a therapy-induced complication or an increased susceptibility to second malignancies due to the leukemic process itself or possibly to immunological deficiencies in CLL. Since two patients received no treatment for CLL, previous therapy does not seem to be a prerequisite for the development of CML.

Abnormalities of B-cell activation and immunoregulation in splenectomized patients

Using a reverse hemolytic plaque assay as the effector system, we studied 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 (ISC) and severely decreased responses to the polyclonal activator pokeweed mitogen. 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, co-culture experiments with unseparated and separated lymphocytes were performed. These revealed an impaired T-helper cell capacity as well as an intrinsic B-cell defect. Marker analyses 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 B-cell as well as the T-helper/inducer-cell population.

Impaired B lymphocyte reactivity in patients after radiotherapy

The effect of therapeutic irradiation upon B lymphocyte function was investigated in patients with various malignancies. The test system used was a reverse hemolytic plaque assay, which made it possible to study the activation and differentiation of B lymphocytes into immunoglobulin-secreting cells (ISC). Peripheral blood lymphocytes from normal individuals and patients before and after radiotherapy were stimulated in vitro with the polyclonal B cell activator pokeweed mitogen, and the number of ISC was estimated. B cell reactivity was markedly reduced in those patients who had received irradiation within the last six months. In patients in whom radiotherapy had been terminated more than 12 months before the lymphocytes were tested, B cell reactivity was comparable to that of patients prior to radiotherapy. By means of marker analyses, there was a reduction of B lymphocytes and T lymphocytes in the peripheral blood with a preponderance of T helper cells. Several mechanisms--e.g., reduced or defective B cell differentiation, altered regulatory T-helper or suppressor cell function or activation of suppressive monocytes--could be responsible for impaired B cell reactivity after radiotherapy.

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.

Modulation of human lymphocyte functions by group A streptococci

Intact (heat-inactivated) bacteria and isolated cellular components of pathogenic group A (M type 5 or 12). B. C. and G streptococci were used to evaluate the in vitro reactivity of mononuclear cells (MNC) from peripheral blood of healthy donors and from human tonsils. High doses of A-streptococcal cells, cell walls, and cell membranes stimulated DNA synthesis, production of leukocyte migration inhibitory factor (LIF), and immunoglobulin (Ig) secretion in MNC from all donors. A streptrococci stimulated higher proliferation rates and larger numbers of plaque-forming cells (PFC) in tonsil cell cultures than in blood MNC cultures. Polyclonal activation of both tonsil and blood B lymphocytes by A-streptococcal cell components was T cell and monocyte dependent, thus showing a similarity between these structures and pokeweed mitogen (PWM), which is a polyclonal T-cell activator (PTA). Cocultivation studies demonstrated that, in the presence of A streptococci, precultured MNC and T cells can suppress the blastogenic and PFC responses of autologous fresh MNC stimulated by phytomitogen or antigen, which is very similar to the concanavalin A (Con A)-induced activation of suppressor cells. In contrast, similar group B-, C-, and G-streptococcal cell envelope biostructures failed to activate blood or tonsil lymphocytes to proliferate, differentiate, or produce LIF.

[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.

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.

Polyclonal activation of immunoglobulin secretion without prior DNA synthesis in human B lymphocytes induced by Klebsiella pneumoniae

The capacity of various cell preparations of Klebsiella pneumoniae K43 (Klebs) to induce [3H]thymidine uptake and immunoglobulin (Ig) secretion by human mononuclear blood cells (MNC) and their lymphocyte subpopulations was investigated. All Klebs preparations were virtually devoid of mitogenic properties, in contrast to control preparations of pokeweed mitogen (PWM) and group A streptococcal cell membranes (A-ScM). Klebs induced differentiation of B cells into Ig-secreting cells. B-cell populations that were sufficiently depleted of T cells to be unresponsive to A-ScM ("highly purified B cells") showed a marked response to Klebs. Similarly, the number of plaque-forming cells (PFC) in Klebs-driven cultures did not change after restitution of T cells, whereas the presence of restituted T cells augmented the B-cell response to PWM and A-ScM. Radical removal of adherent MNC ("monocytes"), however, completely abrogated the PFC response and [3H]thymidine uptake of both MNC activated by Klebs and MNC activated by PWM or A-ScM.

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.

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.

Demonstration of immunoglobulin-secreting cells in a sensitive reversed hemolytic plaque assay

A sensitive modification of a reversed hemolytic plaque assay demonstrating individual immunoglobulin-secreting cells (ISC) is presented. The test is performed by adding test cells to a monolayer of indicator sheep erythrocytes coated with an IgG fraction of rabbit antiserum against the F(ab')2 portion of human immunoglobulins (Ig). After having added a developing antiserum and complement, hemolytic plaques with a central ISC could be counted in an inverted microscope. In addition, when ISC were killed and fixed in situ in the monolayer, the cells could be further studied by immunofluorescence of their cytoplasmic Ig.

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.

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.