Search PubMed⌕ Search

Biomedical subjects

C Agostini

Publications and source records attributed to C Agostini.

At least 145 records · Page 8Linked to original sources

Natural killer cell function and lymphoid subpopulations in acute non-lymphoblastic leukaemia in complete remission.

A long term follow-up study has been undertaken in 33 patients with acute non-lymphoblastic leukaemia (ANLL) in order to establish whether a correlation exists between the clinical course and the immunologic pattern of lymphoid subpopulations. Peripheral blood lymphoid cells have been investigated longitudinally (each 1 to 4 months) during complete remission (CR), by morphologic, phenotypic and functional analyses. Particular attention has been paid to the evaluation of the natural killer (NK) cell compartment, by the detection of cells expressing an NK-related phenotype and by NK in vitro assay. Among the patients so far evaluable, 20 relapsed (R) and 10 are long survivors in CR 'off therapy' (LS). The most relevant finding was represented by statistically higher values of NK activity observed in LS vs. R patients (P less than 0.01). The removal of adherent cells before the NK assay, performed to investigate the possible inhibitory effect on NK function played by the macrophage component, abolished this difference, due to a selective increase of NK function in the R group. The longitudinal study revealed that NK activity tended to decrease in individual patients who subsequently relapsed. These data suggest a possible role of NK cells in the relapse control of ANLL, although it cannot be excluded that the low level of NK activity observed in the R group is the result of impending relapse rather than its cause.

Adolescent↗

Different types of cytotoxic lymphocytes recovered from the lungs of patients with hypersensitivity pneumonitis.

To better characterize the cytotoxic lymphocytes present in the lung of patients with hypersensitivity pneumonitis (HP), we studied cells recovered from bronchoalveolar lavage (BAL) of 5 subjects with farmer's lung disease. Specifically, this cytotoxic activity was evaluated: (1) in resting conditions and after boosting with interleukin-2 (IL-2) against NK-sensitive, NK-insensitive target cell lines, and against specific antigen-sensitized (Micropolyspora faenl) autologous monocytes; (2) after removal of NK-related populations; (3) in blocking experiments with CD3 and CD2 monoclonal antibodies. It has been demonstrated that lung lymphocytes from patients with HP in resting conditions are able to lyse both NK-susceptible and NK-resistant targets and that IL-2 is able to induce BAL cells to generate lymphokine-activated killer (LAK) cell activity. Neither resting nor activated HP lung lymphocytes were capable of specific lysis of autologous monocytes previously sensitized with specific antigen. Removal of HNK-1+ or CD16+ cells reduces, but does not completely eliminate the cytotoxic function, whereas blocking with anti-CD3 monoclonal antibody almost completely abolishes the cytotoxicity. All these data taken together suggest that different types of cytotoxic cells are recovered from the BAL of patients with HP, i.e., NK cells and non-MHC-restricted cytotoxic lymphocytes, including LAK cells.

Adult↗

Phenotypical and functional analysis of bronchoalveolar lavage lymphocytes in patients with HIV infection.

The lungs of patients with acquired immunodeficiency syndrome (AIDS) are frequently affected by opportunistic and nonopportunistic infections and pulmonary localizations of Kaposi's sarcoma. The aim of this study was to verify whether, in patients with human immunodeficiency virus (HIV) infections, immunologic pulmonary abnormalities set the stage for the lung complications. For this purpose, a phenotypic and functional characterization of lymphocytes recovered from the bronchoalveolar lavage (BAL) fluid of 24 patients with clinical symptoms and signs of HIV infections was performed (six patients with constitutional disease, five patients with neurologic manifestations, and 13 patients with full-blown AIDS). Our data showed that (1) in patients with HIV, the percentage and absolute number of pulmonary CD8 cells were significantly increased over those in control subjects (in 25% of these patients, mostly with full-blown AIDS, CD8 cells sustained an alveolitis); (2) lung CD4 cells were reduced in percentage but not in absolute number, with the exception of patients with AIDS in whom a significant decrease of the absolute number of BAL CD4 cells has been found (further phenotypic analysis of CD4 lymphocytes showed a reduction of the expression of T4A, B, and E with respect to the T4, T4C, T4D, and T4F epitopes); (3) although the number of BAL cells bearing NK-related determinants was increased, we were unable to demonstrate any in vitro natural killer cell activity. We suggest that the impairment of a proper NK activity in the lungs of these patients might be central to the mechanisms leading to the in situ immunodeficiency state and to the pulmonary complications characterizing AIDS.

Acquired Immunodeficiency Syndrome↗

Origin of the soluble interleukin-2 receptor in the serum of patients with hairy cell leukemia.

High levels of soluble IL-2 receptor (sIL-2R) are detectable in the serum of HCL patients. To determine the cell source of this molecule, we evaluated the presence of sIL-2R in the supernatants obtained from in vitro cultures of leukemic (hairy cell, HC) and non-leukemic lymphocytes from six untreated HCL patients and from an additional four patients under therapy with rIFN-alpha 2. We demonstrated that cultured HCs at resting conditions were able to spontaneously release the sIL-2R, whereas control enriched B cells did not. This phenomenon was present only when culturing HCs recovered from patients observed at the time of diagnosis but was not observed during treatment with rIFN-alpha 2. Following activation in vitro with a series of different stimulatory agents including BCGF, phorbol myristate acetate, and anti-human IgM antibody, cultured HCs increased their capability to shed the IL-2R molecules. On the other hand, the release of sIL-2R from enriched T cell populations from HCL patients did not significantly differ from the value obtained in controls. Taken together, these findings provide evidence that leukemic B cells represent the main source of sIL-2R in HCL patients and further emphasize the importance of evaluating this parameter as a relevant marker for monitoring the effectiveness of rIFN-alpha 2 therapy.

Adult↗

Immunohistochemical analysis of sarcoid granulomas. Evaluation of Ki67+ and interleukin-1+ cells.

Proliferating cells have been immunophenotypically characterized in lymph node and bronchoalveolar lavage (BAL) samples obtained from patients with active and inactive sarcoidosis with the cell-cycle-related antigen Ki67. Ki67 monoclonal antibody was used by combined immunohistochemical methods together with antibodies recognizing macrophage- and T-cell-subset-related antigens using avidin-biotin peroxidase (ABC) and alkaline phosphatase-anti-alkaline phosphatase (APAAP) systems. Many proliferating Ki67+ cells were found in affected mediastinal lymph nodes. These cells were mainly located around granulomas and exhibited phenotypical markers of helper/inducer T cells (CD3+, CD4+). Ki67+ macrophages could not be detected in the same lesions with this technique. A different picture was found in BAL preparations where proportions of both T lymphocytes and macrophages were Ki67+. The presence of replicating lymphocytes could be correlated to disease activity, whereas the proportions of Ki67+ macrophages did not show significant differences between active and inactive disease. Interleukin-1 (IL-1) expression was investigated in the same samples with a specific antiserum. Epithelioid macrophages in granulomas and BAL macrophages in all cases exhibited cytoplasmic staining revealing an activated status. Interestingly, giant cells in granulomas were mainly devoid of IL-1 immunoreactivity. These studies support the concept that activated cells at different sites of ongoing inflammation play a central role in the mechanisms accounting for granuloma formation.

Adult↗

The lymphoproliferative disease of granular lymphocytes. A heterogeneous disorder ranging from indolent to aggressive conditions.

A multiparameter analysis, which included the evaluation of clinical features, cell morphology, karyotype, phenotypic and functional immunologic findings, and T-cell receptor beta-chain configuration was performed on 34 patients with lymphoproliferative disease of granular lymphocytes (LDGL). The two-fold aim of the study was to identify the most useful tools that would more accurately characterize these patients and to deal with the problem of classifying these lymphoproliferative disorders. The data presented in this article suggest that a single parameter may not be sufficient to define the nature of the proliferating cells or to predict the clinical course of the disease and prognosis for the patient. The use of a multiparameter approach, however, may reach this goal, thus providing important prognostic and therapeutic information. Our study supports the concept that lymphoproliferative disease of granular lymphocytes is a heterogeneous disorder that ranges from indolent and possibly reactive conditions to the manifestation of aggressive malignancies.

Adult↗

Immunologic abnormalities in angioimmunoblastic lymphadenopathy.

In this study we describe the results of phenotypic, serologic, and functional analyses performed in nine patients with angioimmunoblastic lymphadenopathy (AILD). The study investigates the nature of the T-cell defects which seem to represent a consistent feature in this disease. The study, based on the analysis of T-cell subsets with monoclonal antibodies and on functional in vitro tests, showed the following main abnormalities: reduction of the absolute number of circulating T-cells; inversion of the CD4/CD8 ratio, both in the peripheral blood and in the involved lymph nodes; high percentages of activated T-cells (CD8+/HLA-DR+); defective T-cell response in vitro to the PHA mitogen; and minimal helper and enhanced in vitro suppressor functions. Some of these immunologic dysfunctions are also observed in acquired immune deficiency syndrome (AIDS) which has in common with AILD several clinical features. However, no evidence of HTLV-III infection could be demonstrated in our patients with AILD.

Acquired Immunodeficiency Syndrome↗

Pulmonary alveolar macrophages in patients with sarcoidosis and hypersensitivity pneumonitis: characterization by monoclonal antibodies.

Using a panel of monoclonal antibodies (MoAbs), the frequency of cells bearing Class I and Class II major histocompatibility complex (MHC) determinants, transferrin receptor (TR) sites, and interleukin-2 receptors (IL-2R) has been evaluated on pulmonary alveolar macrophages (PAM) recovered from the bronchoalveolar lavage (BAL) fluid of 21 patients with pulmonary sarcoidosis (including 11 cases with active sarcoidosis and 10 cases with inactive disease), 8 patients with hypersensitivity pneumonitis (HP), and 6 normal non-smoking volunteers. When the frequency of Class II DR-positive cells was considered, 64.3% of control PAM expressed HLA-DR products. No statistically significant differences were observed between controls and sarcoid patients, while HP patients showed an enhanced proportion of DR+ PAM with respect to normal PAM (P less than 0.05). On the contrary, the frequency of PAM expressing HLA-DQ molecules was higher in both active sarcoidosis and HP patients with respect to patients with inactive sarcoidosis and normal subjects (P less than 0.001). A statistically significant increase in Class I antigen-positive PAM has been demonstrated in HP patients as compared to controls (P less than 0.05). Active sarcoid patients showed a higher number of PAM-bearing TR sites than controls and other groups of patients considered (P less than 0.001). An increase in the percentage of IL-2R-positive PAM has been demonstrated in active sarcoidosis (P less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Alveolitis, Extrinsic Allergic↗

Alpha-interferon activated cytotoxic lymphocytes in hairy cell leukemia patients: evaluation of cytotoxic events.

To further define the mechanisms responsible for the alpha-interferon (alpha-IFN) efficacy in the treatment of hairy cell leukemia (HCL), experiments were carried out to specify the cytotoxic events taking place following this type of therapy. Although an increased natural killer (NK) activity was demonstrable after alpha-IFN treatment, evidence has been provided that hairy cells were not specifically lysed either by fresh autologous/allogenic NK lymphocytes or by lymphokine activated killer (LAK) cells. This property could not be induced in vitro by alpha-IFN or by interleukin-2 (IL-2). Our data favour the hypothesis that the increase of NK cell activity observed following alpha-IFN therapy has not a direct antineoplastic effect but is likely to be of relevance for a non-specific enhancement of the host immune system. In alpha-IFN treated HCL this latter property may account for the better resistance to infections which usually represents the major cause of mortality in these patients.

Adult↗

Rearrangement for the T-cell receptor gene and co-expression of immature T-cell markers and natural killer cell phenotype, in a patient with acute lymphoblastic leukaemia.

We describe a patient with acute lymphoblastic leukaemia whose blasts co-expressed immature T-cell markers and nearly the entire phenotypic repertoire of NK cells. The T-cell nature of the proliferating blasts was proven by the demonstration of the rearrangement for the beta-chain of the T-cell antigen receptor. Although an abnormal phenotypic expression related to the neoplastic proliferation cannot be formally excluded, it is possible that the cells in this patient may represent the clonal expansion of a normal subpopulation of T-cell lineage NK-related cells frozen at an early stage of differentiation. These features provide arguments for discussing the controversial issue of the ontogeny of NK cells and their relationship to the T-cell lineage.

Acute Disease↗

High serum levels of soluble interleukin 2 receptor in patients with B chronic lymphocytic leukemia.

By using an enzyme-linked immunosorbent assay, the presence of the soluble form of the interleukin-2 receptor (sIL-2R) was evaluated in the peripheral blood of 54 patients with B cell chronic lymphocytic leukemia (B-CLL). Serum levels of sIL-2R were correlated with clinical features, relevant hematologic and immunological data, and in some cases, with in vitro functional studies. In 51 patients (94.4%), the levels of sIL-2R were increased as compared with normal age-matched controls (1,781 U/mL +/- 231 v 276 U/mL +/- 26, respectively; P less than .001). Although this increase was observed in all stages of the disease and independently of several hematologic and immunologic parameters, a trend toward lower levels of sIL-2R was documented in patients with a less-invasive disease. When the values were correlated with the functional status of the residual T cell population, it was found that patients with the lowest levels of sIL-2R showed the best mitogenic response and helper capacity. It is suggested that in B-CLL patients the high levels of serum sIL-2R, capable of binding to its ligand, may block the T cell-produced IL-2, thus contributing toward a defective physiological action by this lymphokine. In turn, this defective availability of IL-2 may play a part in the abnormal immunoregulation that is implicated in the hypogammaglobulinemia, susceptibility to infections, and incidence of second neoplasias often observed in this disease.

Aged↗

Soluble interleukin-2 receptors in the sera of patients with hairy cell leukemia: relationship with the effect of recombinant alpha-interferon therapy on clinical parameters and natural killer in vitro activity.

In this study we provide evidence that the sera of patients with hairy cell leukemia (HCL) contain a factor that can prevent the binding of a monoclonal antibody specific for interleukin-2 receptor (IL-2R) to its target. This factor corresponds to the soluble form of IL-2R (sIL-2R), as assessed by a specific enzyme-linked immunosorbent assay test, and appears to be released by neoplastic hairy cells. The serum sIL-2R levels were very high at diagnosis and significantly reduced during recombinant alpha-interferon (rIFN alpha 2) therapy. Values of sIL-2R appeared to be inversely related to the natural killer in vitro function displayed by peripheral blood mononuclear cells from the same patients. The presence of sIL-2R in the serum of patients with HCL might be involved in the impairment of cell-mediated immunity observed in these patients and could represent a valuable marker for monitoring different phases of the disease and for modulating IFN therapy.

Antibodies, Monoclonal↗

Cytotoxic in vitro function in the lymphoproliferative disease of granular lymphocytes.

In 20 patients with lymphoproliferative disease of granular lymphocytes (LDGL) the cytotoxic in vitro function of peripheral blood mononuclear cells was studied against both NK sensitive (K-562) and NK resistant target cells (Daudi). Cytotoxicity was analysed at resting conditions and after in vitro pre-incubation with recombinant alpha 2-interferon, gamma-interferon and interleukin 2. At resting conditions, a heterogeneous cytotoxic picture was observed against the K-562 targets, with 11 of the 20 patients showing a normal or increased NK activity, and nine an impaired function. Against the Daudi targets, unstimulated cells from all patients displayed a normal cytotoxic activity. Following in vitro stimulation, an increased lytic function against K-562 cells was demonstrated in six of the nine patients with low basal values, in three after boosting with all lymphokines tested and in three with interleukin 2. In three of these six patients incubation with interleukin 2 also produced an increased cytotoxic function against Daudi target cells; this phenomenon may be associated to the lymphokine-activated killer (LAK) system. The importance of investigating the cytotoxic in vitro function in LDGL patients to further characterize the biological features of GL and its relevance to better define the nature of this disease are discussed.

Adult↗

Increased levels of soluble interleukin-2 receptor in the serum of patients with human immunodeficiency virus infection.

The serum levels of a soluble form of the interleukin-2 receptor (sIL-2R) were investigated in 92 patients with human immunodeficiency virus (HIV) infection, ranging from asymptomatic cases to full-blown AIDS. Increased values were found in 69.5% of cases. The overall mean was significantly higher (p less than 0.001) in HIV-infected patients (mean +/- SD = 709.3 +/- 369.4 U/ml) than in the seronegative risk group controls (383.9 +/- 140.5) and normal controls (256.4 +/- 114.5). No major differences were found among the patient groups (asymptomatic infection, persistent generalized lymphadenopathy, symptomatic infection, and full-blown AIDS). These data suggest that the measurement of serum sIL-2R levels may represent a useful biological tool for evaluating T-cell activation phenomena occurring in HIV infection. Since the soluble interleukin-2 receptor maintains the capacity of binding interleukin-2, the increased levels found in HIV infection may play a contributory role towards the in vitro and in vivo impairment of a number of interleukin-2-dependent functions described in this disease. On clinical grounds, the excess of sIL-2R could help to explain the lack of therapeutic effect and little immunological variations following the in vivo administration of interleukin-2.

Acquired Immunodeficiency Syndrome↗

Lung T cells in hypersensitivity pneumonitis: phenotypic and functional analyses.

Cells recovered from bronchoalveolar lavage (BAL) and tissue sections from transbronchial lung biopsies were studied in 16 patients with symptomatic hypersensitivity pneumonitis (HP) and in six subjects with a similar history of exposure but without features of disease by using a series of monoclonal antibodies (MoAb) detecting different lymphocyte subpopulations, including T and T subsets, B lymphocytes, and natural killer (NK) cells. Their functional activities in cytotoxic and suppressor assays and the microenvironment in the lung by using immunohistological techniques were also evaluated. It has been demonstrated that the majority of cells recovered from BAL of HP patients are represented by T8 lymphocytes, with a relevant imbalance of the T4/T8 ratio (p less than 0.001). HNK-1+ cells were markedly increased (p less than 0.001), whereas the frequency of cells bearing other NK-related markers (NK-15, VEP 13, Ab8.28, T10, M1, and Fc gamma R) were not significantly increased with respect to controls. Immunohistological study confirmed that the majority of cells infiltrating lung parenchyma are T8+ lymphocytes. The number of HNK-1+ cells detected on lung biopsies was very low in all cases, even in patients with the highest values on BAL suspensions. The evidence of cells bearing the proliferation-associated markers (Tac and T9 antigens) seems to support the hypothesis of a local proliferation in the lung. In terms of phenotypic analysis, the results observed in the group of asymptomatic individuals are qualitatively superimposable on those observed in the HP group, but the magnitude of the phenomenon is less prominent and therefore the data are not as statistically significant as that produced by the comparison between HP patients and the same controls. Functional analysis of BAL T cells from both HP patients and asymptomatic individuals showed suppressor activity in vitro, as determined by the ability to influence a pokeweed mitogen (PWM)-driven B cell differentiation assay. BAL cells from HP patients were also able to display a definite cytotoxic function in vitro, whereas BAL lymphocytes from asymptomatic subjects did not. Taken together, these data demonstrated that cells responsible for the alveolitis in patients with HP are characterized by the expansion of T cells with the phenotype and functions of both suppressor and/or cytotoxic lymphocytes. This expansion is likely to be related to a local immunologic response to the antigenic stimulus and may provide new insights into the pathogenetic mechanisms of this disease, its pathological pattern, and its management.

Adult↗

Activated T cells with immunoregulatory functions at different sites of involvement in sarcoidosis. Phenotypic and functional evaluations.

Cells from recovered BAL fluid and from infiltrates in different involved tissues (lungs, lymph nodes, conjunctiva, liver, spleen, and skin) were studied in 22 patients with active sarcoidosis in order to define the surface phenotype, functional in vitro properties, and topographic distribution of the cells in granulomatous lesions. Our data demonstrated a compartmentalization of activated T cells with immunoregulatory functions from the blood to all sites of disease activity. In fact, these cells were found to express the T4+ Leu 8- 5/9+ T17- phenotype, which belongs to cells with helper activity, and that provide heightened responses in functional assays of helper activity, IL-2 release, and the ability to respond in AMLR's. Both a cellular redistribution and a local in vitro replication account for this tissue compartmentalization in sarcoidosis. The microanatomic location of activated T cells, as defined by immunohistological evaluation, showed that the state of activation in these T cells may be a consequence of an intimate contact between helper cells and macrophages within the sarcoidosis granulomas.

Adult↗