Cell-mediated immune deficiency in Hodgkin's disease

Association of Hodgkin's lymphoma with Epstein Barr virus infection

The role of Epstein Barr virus (EBV) in the onset of Hodgkin's lymphoma has been a subject of ongoing research. However, confirmation of EBV oncogenic involvement was not possible due to the small number of neoplastic cells characteristic for this type of tumor. Presence of EBV infection in neoplastic and non-neoplastic cells was analyzed in 81 cases of Hodgkin's lymphoma. In neoplastic cells, using an immunohistochemical method, latent membrane protein 1 (LMP1) was found in 33,3% of cases, while in situ hybridization results demonstrated the presence of EBER RNA in 48,1% of the cases. EBER RNA was found in non-neoplastic lymphocytes in 38,3% of cases. EBV is most frequently associated with Hodgkin's lymphoma in the first and seventh decade of life, specifically the nodular sclerosis subtype. No apparent difference was observed in the association of Hodgkin's lymphoma with EBV between genders, or in relation to clinical stage of the disease and average age of the patient. However, association with childhood age is significantly greater in comparison to adults. EBV associated disease shows a significantly greater prevalence in T lymphocytes. Slightly more abundant are cytotoxic T lymphocytes, which are also more frequently in contact with Reed-Sternberg cells, although there is no difference in number and positioning of histiocytes. Variations between the data on the association of EBV with Hodgkin's lymphoma among studies from different parts of the world suggest that factors of age, gender, ethnic background and social status might present biological modifiers of EBV influence on the pathogenesis of this neoplasm. The differences in non-neoplastic infiltrate EBV+ and EBV- lymphoma indicate the effect of the virus on the immune interaction of tumor and host in this disease.

HIV-associated Hodgkin's disease. Biologic and clinical aspects

The incidence of HD appears to have increased in HIV-infected individuals, with HIV-seropositive intravenous drug users most likely to develop the disorder. All groups at risk for HIV, however, may develop HD. The pathologic spectrum of HD in the setting of HIV infection is distinct from that seen in "de novo" HD in the United States, with the majority of patients diagnosed with the mixed cellularity subtype, as opposed to the more usual occurrence of nodular sclerosis in "de novo" disease. The presence of fibrohistiocytic stromal cells within involved tissues is also a distinct characteristic of HIV-associated HD. Epstein-Barr viral genome has been detected within tumor cell nuclei, and it may be involved in the pathogenesis of disease. Clinically, patients often present with systemic "B" symptoms and widely disseminated extranodal disease, seen in 75% to 90%. Bone marrow is involved in 40% to 50% of cases at diagnosis. Complete remission may be achieved in approximately 50% of patients after use of combination chemotherapy, but median survival is short, in the range of 12 to 18 months. Death is often due to bacterial or opportunistic infection (or both), often occurring in the setting of chemotherapy-induced neutropenia.

Influence of Epstein-Barr virus encoded latent membrane protein 1 on the expression of CD23 antigen, ICAM-1 and LFA-3 in Hodgkin and Reed-Sternberg cells. A morphometric analysis

Epstein-Barr virus (EBV) latent membrane protein 1 (LMP 1) is expressed in Hodgkin and Reed-Sternberg (HRS) cells in about one half of Hodgkin's disease (HD) cases. In vitro, LMP 1 induces B-cell expression of CD23 antigen, ICAM-1 and LFA-3. To evaluate the influence of LMP 1 on the expression of these molecules in HRS cells in vivo, we performed a quantitative frozen section immunohistological study comparing the numerical density (cells per unit area) of HRS cells expressing the CD23 antigen, ICAM-1 and LFA-3 in 14 LMP 1-positive and 13 LMP 1-negative HD cases. CD23 antigen was demonstrated in HRS cells in five LMP 1-positive and three LMP 1-negative cases (not significant). The relative density of HRS cells tended to be lower in the LMP 1-positive than in the LMP 1-negative cases, but this did not reach significance (0.2 > 2p > 0.1). All recognizable HRS cells expressed ICAM-1 and LFA-3 irrespective of LMP 1 status. We conclude that expression of CD23 antigen and LMP 1 are not coordinated in HD. Although LMP 1 may have some influence on CD23 antigen expression, it is unlikely that the latter is of importance in the putative EBV induced growth transformation of HRS cells in vivo.

The alternative pathway of T cell activation: biology, pathophysiology, and perspectives for immunopharmacology

The application of monoclonal antibodies and recombinant mediators to studies of T cell activation has led to a new concept regarding the central mechanisms underlying specific immune responses in man. Stimulation of human T cells to express their functional programs with regard to immunoregulatory activities and effector functions can be mediated through several distinct mechanisms or pathways. We report on the recently discovered T3-Ti antigen receptor independent mode of human T cell activation, namely, the T11-mediated "alternative pathway." Recent evidence supports the notion that this pathway plays an important role in the immune response in man and that failure to activate T cells through T11 is associated with immunodeficiency. The characterization of functional epitopes of the T11 molecule along with functional investigations on patients suffering from etiologically different cases of immunodeficiency provides important perspectives for future pharmacological interventions into the human immune system. It seems likely that immunologic disorders such as autoimmune disease and immunodeficiencies result from overamplification or blockades of the "alternative pathway of T cell activation" and that the T11 epitope represents a potential site for selective inhibition of the "alternative pathway of T cell activation," e.g., by means of synthetic peptide analogues. Conversely, high affinity ligands to the T11 epitope might be suitable for immunostimulation immunodeficiencies that result from circulating blocking factors of the LFA-3/T11 interaction.

Peripheral blood lymphocyte response to recombinant and non-recombinant interleukin 2 in previously treated patients with Hodgkin's disease, long-time off-therapy

13 patients with Hodgkin's disease (HD) previously treated, 9 of whom were long-time (more than 2 yr) off-therapy, were studied for peripheral blood lymphocyte response to interleukin 2 and for lymphocyte subpopulations by means of in vitro cultures and monoclonal antibodies. The aim of the study was to ascertain the role played by interleukin 2 in the impaired cell-mediated immunity of HD patients. The results show a response of peripheral blood mononuclear cells of HD patients to either the T cell-specific polyclonal mitogens PHA and Con A or to the T cell-dependent, although B cell-specific, PWM, most significantly decreased compared to the normal response. As far as the interleukin 2 involvement in HD is concerned, our study suggests: an impaired endogenous interleukin 2 production by T lymphocytes, a most probable deficiency of the interleukin 2 receptor (Tac) expression and 3) a decrease of the number and/or of the function of NK cells no longer responsive in vitro to interleukin 2. The phenotypic analysis of peripheral blood mononuclear cells showed a slight decrease of total T cells (T3+), of the helper/inducer subset (T4+) and of the T4+/T8+ cells ratio. Our data seem to support the rationale for a therapeutical approach with interleukin 2 in controlled clinical trials also in HD patients, according to the experiments in progress in solid tumor patients.

Cyclic AMP and cyclic GMP phosphodiesterase activities in Hodgkin's disease lymphocytes

Cyclic nucleotide phosphodiesterase (PDE) activities were studied in peripheral blood monocyte-depleted lymphocytes and enriched T-lymphocyte suspensions from thirteen patients with previously untreated Hodgkin's disease (HD) and fourteen age and sex matched healthy volunteers. Monocyte-depleted lymphocytes from HD patients showed PDE-activities which were two times higher than in their normal counterpart cells. The mean cAMP-PDE activity present in enriched HD T-lymphocyte suspensions was four times higher than in control T-lymphocytes, and the mean cGMP-PDE associated with HD T-lymphocytes was three times higher than in the controls. The hydrolytic activities present in both monocyte-depleted and T-lymphocyte enriched cells suspensions remained unchanged in absence or in the presence of calmodulin and calcium. Since depressed cAMP and cGMP resting levels have been observed in HD lymphocytes and lymphocyte subpopulations, our results suggest that the elevated PDE activities are, at least in part, responsible for the alterations in lymphocyte cyclic nucleotide levels.

Decreased membrane "fluidity" of T lymphocytes from untreated patients with Hodgkin's disease

Plasma membrane "fluidity" of peripheral blood T lymphocytes from untreated patients with Hodgkin's disease (HD) and healthy controls was studied using the fluorescent probes 1,6-diphenyl-1,3,5-hexatriene (DPH) and 1-(4(trimethylamino)phenyl)-6-phenyl-1,3,5-hexatriene (TMA-DPH). In 13 consecutive patients a significant increase of T lymphocyte plasma membrane microviscosity was observed with both DPH and TMA-DPH. These alterations seemed unrelated to the cholesterol (Chol) and phospholipid (PL) content of HD T lymphocytes since the Chol/PL ratio was comparable in both HD and control cells. Since prostaglandin E2 (PGE2) from monocytic origin has been claimed to be responsible for the impairment of cell-mediated immunity (CMI) associated with HD, we studied the effect of exogeneously added PGE2 (0.1 microM) on control subjects T lymphocyte membrane "fluidity". Using the fluorescent probe DPH and the spin labelled fatty acid probe 16 NMS for electron paramagnetic resonance study, we observed a PGE2-induced fluidization of control T lymphocyte membranes which is specifically located in the inner part of the plasma membrane, whereas the plasma membrane surface seemed unaffected by PGE2 as judged by the TMA-DPH probe. Thus, PGE2 does not appear to be responsible for the alterations of T lymphocyte membranes observed in HD. Intrinsic alterations and/or other mediators might be involved.

Quantitative and functional abnormalities of total T lymphocytes in relatives of patients with Hodgkin's disease

Seven patients, long-term survivors of Hodgkin's disease, and 24 of their relatives (parents, siblings and children), together with normal controls were studied for percentages, absolute counts and mitogen-proliferative responses by means of monoclonal antibodies, E rosette technique and in vitro cultures with PHA, ConA and PWM. The aim of the study was to ascertain whether the impaired cell-mediated immunity of Hodgkin's patients was also present in relatives in order to elucidate the still debated etiology of the defect and of the disease (congenital? environmental? infectious?). The results show that both Hodgkin's patients and their relatives have a significant decrease of total T cells (as T3+, T11+ and E rosette-forming cells) in peripheral blood and a significant impairment of polyclonal responses to all the mitogens employed. The Leu-7+ cells (i.e. a consistent amount of natural killer cells) are significantly increased only in the Hodgkin's patients but not in their relatives. The T cell subpopulations (T4 and T8), B cells and monocytes do not show any difference between the patients, their relatives and normal controls. Our results seem to support, at least in part, the presence of a common defect of T cell lineage both in patients and in their relatives, but its etiology still remains uncertain (genetic? environmental?).

Depressed NK cell activity of peripheral blood mononuclear cells in untreated hodgkin's disease: enhancing effect of interferon in vitro

Natural killer (NK) cell activity of unseparated peripheral blood mononuclear cells from 30 untreated patients with Hodgkin's disease and 22 age- and sex-matched normal controls was evaluated using the classical K 562 cells as targets. A significant defect was demonstrated in the patients with stage I-II and seemed to be more profound in patients with advanced disease (stage III-IV) and in those with B symptoms. The differences between subgroups of patients, however, were not statistically significant, mostly because of the wide dispersion of individual data. Pre-incubation of effector cells with alpha A leucocyte recombinant interferon led to a clear increase in NK cell activity in 4 of 6 patients tested, showing that depressed NK activity in Hodgkin's disease is still susceptible to the enhancing effect of interferon, at least in some patients.