Immunologic profile of patients with cured Hodgkin's disease

Normal T-Lymphocyte Function in Patients with Hodgkin's Disease in Long-Lasting Remission

In 18 patients with Hodgkin's disease (HD) in long-lasting remission (more than 5 years), the distribution of circulating T-lymphocytes was analyzed using a series of monoclonal antibodies (OKT3, T4, T8, Leu-7, Leu-11 and T10) and correlated with cell function (helper capacity in a pokeweed mitogen system and natural killer (NK) activity). A reduced proportion of OKT4 (helper/inducer)-positive cells associated with a normal absolute number was consistently accompanied by a significant increase (p < 0.005) in the proportion and absolute number of OKT8 (suppressor/cytotoxic)-positive cells. The OKT4-positive cells, despite their moderate percentage reduction, showed normal helper activity. A more extensive characterization of the lymphoid population in these patients documented a preserved cytotoxic function in a 51Cr release assay and increased proportion of cells expressing NK-associated antigens (Leu-7, Leu-11, OKT10) with a high number of cells coexpressing OKT8 and Leu-7. It is suggested that in patients with Hodgkin's disease in long-lasting remission no laboratory (or clinical) evidence of cellular immunodeficiency can be documented.

Hodgkin lymphoma risk following infectious and chronic inflammatory diseases: a large population-based case-control study from Sweden

Patients with Hodgkin lymphoma (HL) have a well-characterized immune deficiency of T cell function, originally identified by increased susceptibility to certain infections. Epidemiological evidence has long pointed to infectious etiologies in younger HL patients. With the aim of expanding our knowledge on the potential role of pre-existing immune deficiency in HL and an infectious/inflammatory etiology, we conducted a comprehensive population-based case-control study in HL patients diagnosed in Sweden in the period 1965-2004, and their matched controls. In a large population-based study including 7,414 HL patients and 29,240 matched controls, we evaluated the subsequent risk of HL in relation to a broad range of infectious and inflammatory conditions, using unconditional logistic regression. A previous history of any reported infection was associated with an 11 % increased risk of HL (P < 0.05). More specifically, we found sinusitis (odds ratio = 1.81; 95 % confidence interval = 1.06-3.07), tuberculosis (1.76; 1.01-3.07), encephalitis (7.88; 1.97-31.5), and herpes zoster (2.20; 1.11-4.35) to be associated with excess HL risk. A personal prior history of chronic inflammatory condition was not associated with an increased risk of HL (0.94; 0.71-1.14). Our results suggest that underlying immune deficiency is a primary phenomenon in HL. Alternatively, certain infectious agents may be potential HL triggers.

Infections in patients with leukemia and lymphoma

Infectious complications remain a significant issue in the care of patients with hematologic malignancies. Inherent immune defects related to the primary disease process are present in patients with disorders such as chronic lymphocytic leukemia, multiple myeloma, hairy cell leukemia, and Hodgkin lymphoma. Therapy-related immunosuppression is also commonplace in these patients. This includes not only treatment-related neutropenia, but also defects in cell-mediated immunity, such as those that occur with purine analog therapy. In this chapter, we will review the pathogenesis of infection in these disorders, as well as the spectrum of infectious complications seen and suggested strategies for the prevention of infection.

Human immunodeficiency virus associated Hodgkin's disease: report of 45 cases from the French Registry of HIV-Associated Tumors

Clinical and pathological characteristics as well as outcome of 45 Hodgkin's disease (HD) cases collected by the French registry of HIV-associated tumors between January 1987 and December 1989 (all clinically staged according to the Ann Arbor system) were analyzed and compared with those of a cohort of 407 patients with clinical stages (CS) IA to IVB enrolled between September 1981 and August 1988 in a multicentric clinical trial. The route of HIV infection, initial CD4 cell count at the time of HD diagnosis and CDC class of HIV infection were studied as well as the progression to AIDS onset were recorded. HIV-HD is characterized by a predominance of advanced CS (75%), B symptoms (80%) and mixed cellularity histology (49%), as well as by early bone marrow involvement (24%); a specific feature is the rare occurrence of mediastinal involvement (13% in HIV-HD versus 71% in primary HD). With standard therapies, 79% of the patients achieved a complete remission, but hematological and infectious complications were very frequent. The proportion of intravenous drug abusers (IVDA) in HIV-HD (38%) is higher than in French HIV-infected population as a whole (20.8%). Median CD4 cell count was 306/microliters at the time of HD diagnosis, while only 5 cases (11%) were preceded by an AIDS manifestation; progression to AIDS rate was 94% at 2 years. Overall 2-year survival was 41%, with 71% for patients with an initial CD4 cell count over 300/microliters and 0% for those with CD4 cell count lower than 300/microliters (p < 0.01); opportunistic infections were the most frequent cause of death. HIV-HD seems to occur preferentially in.(ABSTRACT TRUNCATED AT 250 WORDS)

Hodgkin's disease during HIV1 infection: the French registry experience. French Registry of HIV-associated Tumors

BACKGROUND

The first cases of Hodgkin's disease (HD) associated with HIV infection were reported in 1984. Since then, short series of seropositive patients suffering from HD have been published. In order to identify the characteristics, treatment response and outcome of HIV-associated Hodgkin's disease (HIV-HD), the data of HIV-HD patients recorded between 1987 and 1989 were analysed and compared with those of primary HD patient and with those of HIV-associated non-Hodgkin's lymphoma (HIV-NHL), registered during the same period.

PATIENTS AND METHODS

The 45 cases of HD collected by the French registry of HIV-associated tumors between January 1987 and December 1989 were included in this study. All patients were clinically staged according to the Ann Arbor system. To compare HIV-HD characteristics with those of primary HD, we used a cohort of 407 patients with clinical stages (CS) IA to IVB, who were enrolled between September 1981 and August 1988 in a multicentric clinical trial. To identify the relationship between HIV-HD and the course of HIV infection we studied, when available, the routes of infection, initial CD4 cell count at the moment of HD diagnostic as well as the CDC class of HIV infection and compared these data with the same parameters observed in 142 HIV-NHL enrolled in the registry during the same period.

RESULTS

HIV-HD is characterized by an increase in mixed-cellularity histology (49%), with a predominance of advanced stages (75%) and B symptoms (80%). A unique observation is made regarding mediastinal involvement, present in only 13% of HIV-HD (71% in primary HD). The HIV-HD/HIV-NHL ratio was significantly higher in intravenous drug abusers than in male homosexuals. Median CD4 cell count was 306/microliters at HIV-HD diagnosis, and only 11% of the cases were preceded by an AIDS manifestation. With standard therapy, 79% of the patients achieved complete remission, but hematological and infectious complications were very frequent. The progression to AIDS rate was 94% at two years and opportunistic infections were the most frequent cause of death. Overall two-year survival was 41% with 71% for patients with initial CD 4 cell counts higher than 300/microliter and 0% for those with CD4 cell counts lower than 300/microliter (P < 0.01).

CONCLUSION

HIV-HD has a particular clinico-pathological profile when compared to primary HD, with a predominance of mixed-cellularity type, a high frequency of advanced stages and a high proportion of patients without mediastinal involvement. Moreover, HIV-HD seems to occur preferentially in the group of subjects infected by needle sharing. Standard HD therapy seems to be efficient but excessively toxic.

Immune deficiency in family members of patients with Hodgkin's disease

Indirect data supporting a preexisting immunologic impairment in patients with Hodgkin's disease (HD) have been presented in recent years. These immunologic defects are supposed to be related to genetic and/or environmental factors. In this study, 65 first-degree relatives and 12 spouses of 21 consecutive patients with HD were studied immunologically. Furthermore, seven twin pairs in which one partner had HD and four additional nonmatched healthy co-twins were also included in the study. A decreased lymphocyte DNA synthesis induced by Concanavalin A, a high spontaneous DNA synthesis, or a low CD4+/8+ ratio was found in 21 (32%) consanguineous, two (17%) nonconsanguineous relatives, and five (50%) healthy co-twins. The corresponding figures for the untreated patients with HD and the control series were 14 of 21 (65%) and 21 of 127 (16%), respectively. Total lymphocyte counts or lymphocyte subpopulations did not differ between HD relatives and controls. The increased frequency of blood lymphocyte defects among consanguineous first-degree relatives favors the existence of a genetically determined immune deficiency in at least a proportion of apparently healthy relatives of patients with HD. However, nongenetic factors such as age and environment may add to the defect.

Dysfunction of monocytes in Hodgkin's disease by excessive production of PGE-2 in long-term remission patients

The candidacidal activity and the production of oxygen radicals by monocytes were investigated in untreated and long-term remission patients with Hodgkin's disease (HD). Both groups showed a decreased candidacidal function of monocytes with a chemiluminescence (CL) response significantly lower and delayed with respect to normal controls. Indomethacin at 1 microgram/ml corrected the monocyte deficiency increasing the CL response to normal values and normalizing the kinetics in the untreated patients. However, in patients in remission, the peak was delayed and followed by a significant increase in the production of oxygen radicals compared with untreated patients. A direct linear correlation was found between the percentages of lysed Candida and maximum CL peak of stimulated monocytes. When prostaglandin E2 (PGE-2) levels, measured in supernatants of cultured mononuclear cells, were plotted against the percentages of killed Candida, an inverse linear correlation was found. Therefore, monocytes from HD patients have a dysfunction in the generation of oxygen radicals and a decreased candidacidal activity associated with excessive production of PGE-2. Indomethacin can correct the oxidative metabolism in the untreated patients while in apparently "cured" patients the disorder persists.

Long-term effects on the immune system following local radiation therapy for breast cancer. 4. Proliferative responses and induction of suppressor activity of the blood lymphocyte population

The long-term effect of local irradiation for breast cancer on the blood lymphocyte population was examined in 149 women who had been disease-free for 5-6 and 10-11 years. The patients were included in a clinical trial aiming at determining the value of pre- and post-operative irradiation (45 Gy) compared to surgery only. It was observed that the relative mitogen responses of lymphocytes to phytohaemagglutinin (PHA) and Concanavalin (Con A) and in a mixed lymphocyte culture (MLC) were significantly lower in irradiated compared to unirradiated patients at least a decade after treatment. The prolonged reductions of mitogen responses after irradiation could partly be due to an increased proportion of lymphocytes which may express suppressor function since the Con A-inducible suppressor activity of lymphocytes was significantly higher in irradiated compared to unirradiated patients.

Abnormal immunoregulation in remission Hodgkin disease

Peripheral blood mononuclear cells from 11 patients with remission Hodgkin disease and 20 normal controls were incubated with irradiated allogeneic lymphocytes in one-way mixed lymphocyte cultures. Simultaneously, modified assays were performed by adding supplemental irradiated PBM, T lymphocytes, or adherent cells autologous to the responders. Baseline allogeneic responsiveness of patients and controls was not different. However, significant suppression (p less than .01) was demonstrated when the cultures were supplemented with patient mononuclear cells or adherent cells, an effect not found with similar supplemental cells from controls. Conversely, T-cell supplementation of control cultures produced more than twofold increases in proliferation but significantly less augmentation in the patients' cultures (p less than .01). T-cell subset analysis in six patients showed decreased helper: suppressor cell ratios. Hodgkin disease patients have adherent suppressor cells, which persist during remission, as well as a defect in T-cell helper function.

Long term effects on the immune system following local radiation therapy for breast cancer. I. Cellular composition of the peripheral blood lymphocyte population

Local radiation therapy for breast cancer depletes the blood of various subsets of lymphocytes. Previous studies showed that the recovery is still incomplete at 30 months. To further elucidate the recovery we examined blood lymphocyte counts of 138 disease-free women and various lymphocyte subsets in 102 of these patients. These patients, 5-6 and 10-11 years earlier, had entered a clinical trial in which preoperative irradiation (45 Gy) was evaluated against postoperative irradiation (45 Gy) or surgery only. Patients who had undergone surgery only served as controls. Total lymphocyte counts of the irradiated patients were still significantly reduced 10-11 years after treatment. This reduction was mainly attributable to a subnormal level of T-cells as determined by the monoclonal antibody Leu-1 and the ability to form rosettes with sheep erythrocytes, whereas the number of non-T cells, expressing C'3 receptors, did not differ significantly from the controls. Within the T-cell population a subset with helper/inducer phenotypes, detected by Leu-3a antibodies, was significantly reduced even 10-11 years after irradiation. T-cells with suppressor/cytotoxic phenotypes, stainable with Leu-2a antibodies, however, had already recovered 5-6 years after irradiation. The duration of the radiation induced reductions of different lymphocyte subsets may be related to the physiological turn-over of the cells or a changed distribution of cells in the body.

Familial longevity and prognosis in Hodgkin's disease

The authors studied the influence of familial longevity on the prognosis in 98 patients with Hodgkin's disease (HD) followed for a long period of time. The survival of parents and grandparents to patients older than 50 years of age who died from progressive HD was significantly shorter than that of ancestors to survivors in the same age group. The excess death rate among relatives to the deceased patients was mainly caused by tuberculosis, which suggests a T-cell defect. The prognostic information achieved by analyzing duration of life of ancestors was superior to that given by the clinical stage. No association between familial longevity and prognosis was observed in young patients (less than or equal to 50 years of age). These findings are consistent with the hypothesis that HD in the elderly may be a separate clinical entity, and may also have important implications as to the understanding and treatment of HD in the elderly.

A prospective study of the changes in immune status following radiotherapy for Hodgkin's disease

In a prospective study, immune status was measured in 23 previously untreated patients with Hodgkin's disease Stage I-IIIA. Assessments of immunologic capacity were performed at diagnosis and repeated after staging laparotomy and after radiotherapy. The immune status was measured using delayed-type hypersensitivity tests to common recall antigens, the number of T- and B-lymphocytes in the peripheral blood, in vitro lymphocyte responsiveness to mitogens, antigens, and allogeneic lymphocytes, and serum levels of immunoglobulins. Skin reactivity was not significantly affected by either the staging laparotomy with splenectomy or the radiotherapy. Absolute T-lymphocyte count increased after splenectomy (P less than 0.025) and decreased after radiotherapy (P less than 0.005 compared to postsplenectomy values). In vitro lymphocyte responsiveness after splenectomy was comparable to the initial presenting level and diminished after radiotherapy (P less than 0.005). Serum levels of IgM were lowered after radiotherapy (P less than 0.05) while the fall was not significant after splenectomy. Three months after radiotherapy, lowest mean T-cells percentages were noted, but the responses to mitogens were significantly higher than those obtained immediately after treatment (P less than 0.01). While the reduction in the proportion of the T-lymphocytes persisted for 18 months, the mean lymphocyte responsiveness to mitogens, antigens, and allogeneic lymphocytes increased on follow-up. Apart from a severe impairment of the immune status following radiotherapy, this study also shows the existence of significant repair mechanisms during the follow-up period.

Increased proportion of suppressor/cytotoxic (OKT8+) cells in patients with Hodgkin's disease in long-lasting remission

The distribution of T-lymphocyte subsets in patients with Hodgkin's disease (HD) at diagnosis and in those disease-free off-therapy for over 5 years, was assessed with OKT monoclonal antibodies. In patients at diagnosis, T-cell subsets appeared substantially balanced with only a moderate reduction in the proportion and absolute number of OKT4 (helper/inducer) positive cells, suggesting that the lymphopenia, constantly associated with HD at diagnosis, is mainly due to a reduction in the helper/inducer T-cell subpopulation. In patients off-therapy, a reduced proportion, but normal absolute number, of OKT4+ cells was constantly accompanied by a significant increase in the proportion and absolute number of OKT8+ cells, compared with patients at diagnosis and normal controls (40% +/- 11 versus 24% +/- 7 and versus 23 +/- 6, respectively). Consequently the OKT4/OKT8 ratio, normal or near normal in patients at diagnosis (1.70 versus 2.00), was significantly reduced in patients off-therapy (0.78 versus 2.00, P less than 0.001). These data suggest that in patients with HD at diagnosis, T-cell subpopulations are substantially normal, while a significant abnormality was observed in patients with HD off-therapy and potentially "cured." Further investigations will better elucidate these findings probably related to the cytotoxic radiotherapy and chemotherapy.

Basic and acidic isoferritins in the serum of patients with Hodgkin's disease

Ferritin concentration has been measured in the serum of patients with Hodgkin's disease (HD) by radioimmunoassays with monospecific antibodies to liver (basic) and HeLa (acidic) ferritin. Elevated levels of serum ferritin with the liver ferritin assay were found only in patients with systemic disease, and were associated with low serum iron. Basic ferritin levels returned promptly to normal when complete remission was achieved. High levels of serum ferritin with the HeLa ferritin assay were found in 94% of all untreated patients. Acidic ferritin concentration was not related to systemic symptoms or alterations of iron metabolism, and returned to within the normal range only 1-2 yr after complete remission. These findings suggest that basic and acidic isoferritins can be distinguished in terms of biological and clinical significance. Basic ferritin is synthesized by the reticuloendothelial cells and the high values found in patients with systemic symptoms are compatible with the non-specific changes known to occur in the reticuloendothelial system during inflammation. In patients with untreated HD an elevated serum concentration of basic ferritin can be considered a marker of systemic symptoms and, therefore, an unfavourable prognostic factor. Acidic ferritin may be derived from abnormal lymphocytes and/or monocytes, including malignant cells, and its serum concentration may be of value in following the course of remission.

Lymphocytotoxic serum factors and lymphocyte functions in untreated Hodgkin's disease

The prevalence of complement dependent, cold-reactive lymphocytotoxic serum factors (LT) was studied in 80 untreated patients with Hodgkin's disease by a microcytotoxicity assay. Sera from 24 patients (30%) contained LT as judged from at least 50% lysis of lymphocytes from 16 to 23 randomly selected normal donors. The spontaneous incorporation of 14C-thymidine into blood lymphocytes from patients with LT was significantly higher than that of lymphocytes from LT-negative patients and from healthy controls. Total lymphocyte and T-cell counts, Concanavalin A, and pokeweed mitogen-induced lymphocyte DNA synthesis were lower in patients with LT. Lymphocytotoxic sera were more frequently encountered in patients with B symptoms, advanced disease, or nodular sclerosis/lymphocyte predominance histopathologic characteristics. LT were often found in patients with large and tumor-involved spleens. The ability of patient's serum to inhibit control lymphocyte response to Concanavalin A stimulation did not differ between LT-positive and LT-negative patients. We conclude that the presence of LT is associated with a quantitative and qualitative impairment of blood T-lymphocytes in untreated patients with Hodgkin's disease.

Immunity in Hodgkin's disease: status after 5 years' remission

Immunological indices have been reassessed in 27 patients in remission from Hodgkin's disease for 5 years after treatment and the findings correlated with initial treatment and splenectomy status. Neutrophil counts were lower and lymphocyte and monocyte counts higher at 5 years' remission than at presentation; the increases in lymphocyte count were mainly a feature of the splenectomized patients. Neutrophil function (nitro-blue tetrazolium) was unchanged in remission but cellular immunity (leucocyte migration inhibition and lymphocyte transformation) was depressed at 5 years and progressive falls in serum immunoglobulins were noted. Low values of IgG and IgM were particularly found in patients who had splenectomy and chemotherapy; there was however no excess of infections in this small group.

Longitudinal studies of blood lymphocyte capacity in Hodgkin's disease

Blood lymphocyte functional capacity and serum immunoglobulins were studied in 40 patients with Hodgkin's disease (HD) admitted to Radiumhemmet, Stockholm, before treatment and in complete remission 2-56 months following termination of radiotherapy (total nodal irradiation [TNI]; n = 29) or chemotherapy (MOPP; n = 11). Lymphocyte studies included determination of total lymphocyte and T-cell counts and evaluation of spontaneous DNA synthesis during the first day of culture and mitogen-(concanavalin A, pokeweed mitogen) and antigen (purified protein derivative, PPD)-induced activation on the third day. Blood lymphocyte and T-cell counts decreased dramatically following TNI. A slow restitution was seen, but pretreatment levels were not reached even four years following therapy. The responses to ConA and PPD but not PWM were significantly reduced shortly after TNI. The mitogen response did not increase with time as did the PPD response. Lymphocyte counts and lymphocyte stimulation, which were severely depressed before treatment of patients in the chemotherapy group, remained unchanged 2-36 months after termination of therapy. A significant reduction of IgM levels was observed regardless of the mode of treatment. Splenectomy prevented the profound reduction of blood lymphocyte and T-cell counts following therapy but did not influence the other immunologic variables under study.

Spontaneously DNA synthesizing blood and spleen lymphocytes in Hodgkin's disease

Spontaneously DNA synthesizing blood and spleen lymphocytes in 9 patients with Hodgkin's disease have been studied by surface markers and by autoradiography after in vitro labelling with 3H-thymidine of cell specimens separated according to size. The findings have been related to functional characteristics of blood lymphocytes. The distribution of E and EAC rosetting cells in blood and spleen was similar also after separation according to cell size. The number of mainly large activated blood and spleen cells was increased in patients as compared to controls. Both E and EAC rosetting cells participated in this unexplained cell challenge.

Malignant lymphoma and exposure to chemicals, especially organic solvents, chlorophenols and phenoxy acids: a case-control study

A number of men with malignant lymphoma of the histiocytic type and previous exposure to phenoxy acids or chlorophenols were observed and reported in 1979. A matched case-control study has therefore been performed with cases of malignant lymphoma (Hodgkin's disease and non-Hodgkin lymphoma). This study included 169 cases and 338 controls. The results indicate that exposure to phenoxy acids, chlorophenols, and organic solvents may be a causative factor in malignant lymphoma. Combined exposure of these chemicals seemed to increase the risk. Exposure to various other agents was not obviously different in cases and in controls.

Blood lymphocyte functions in relation to splenic weight and tumor involvement in untreated Hodgkin's disease

Spontaneous and mitogen induced blood lymphocyte DNA synthesis was studied in relation to weight and tumor involvement of the spleen in 33 untreated patients with Hodgkin's Disease. Splenic tumor involvement was found in 14 patients. In this group there was a strong inverse correlation between spleen weight and lymphocyte DNA synthesis induced by PWM, ConA and PPD. In patients with uninvolved spleens the spontaneous blood lymphocyte DNA synthesis increased with spleen weight. No correlation with the mitogen response was observed in this group.

Long-term influence of splenectomy on immune functions in patients with Hodgkin's disease

Immunological functions of 9 non-splenectomized and 8 splenectomized patients with Hodgkin's disease were studied before and after treatment. The two groups compared well with regard to age, clinical and immunological findings at diagnosis and observation time. When retested, all patients had enjoyed an unmaintained complete remission for 2 to 5 years following total nodal radiotherapy. After therapy, total lymphocyte and T-lymphocyte counts decreased in non-splenectomized patients but remained unchanged in splenectomized patients. The blood lymphocyte DNA synthesis after activation by concanavalin A or pokeweed mitogen persisted at the same low level after treatment. The delayed skin hypersensitivity and the lymphocyte activation by PPD antigen were restored in several patients in both groups. The IgM concentration decreased after therapy independent of splenectomy. The IgA level was low in non-splenectomized patients. Splenectomy seems to protect from the therapy-induced lymphocytopenia. No alterations of immunoglobulins and blood lymphocyte functions could be ascribed to splenectomy.

The immunopathology of Hodgkin's disease

Answers are beginning to emerge to the questions posed in the introduction to the preceding section. In vitro techniques that allow characterization of malignant cells have particular relevance when, as in Hodgkin's disease, the precise identity of the cells remains in doubt. Monolayer tissue cultures derived from Hodgkin's disease tumours and maintained as established cell lines have proven amenable to a variety of cytogenetic, immunological, enzymatic, and ultrastructural studies. Tissue culture experiemnts, in conjunction with meticulous immunological studies of individual Reed-Sternberg cells from non-cultured tumours, suggest that neoplastic cells of Hodgkin's disease are related to, and possibly derived from, cells of the monocyte-macrophage system. The lymphocytes that comprise an integral part of the cellular proliferation and form the basis for histological subclassification of the tumour could be a manifestation of cell-mediated immunity against this non-lymphoid malignant cell. The immunodeficiency of patients with untreated Hodgkin's disease of limited anatomical extent is not the primary event of the disorder and probably not related to the site at which the aetiological agent acts. The deficit does not result solely from impaired T-cell function and appears to arise as a consequence of excessive suppressor cell activity. Inhibitory monocyte-lymphocyte interactions may be one of the causes of defective cell-mediated immunity in Hodgkin's disease. The possible significance of elevated levels of circulating immune complexes in the serum of patients with Hodgkin's disease is indicated by the finding that such complexes react with cells of long-term monolayer tissue cultures derived from the tumour. Circulating immune complexes may be one source for intracellular immunoglobulin in non-cultured Hodgkin's disease cells. The presence of polyclonal immunoglobulin G on the membrane and within the cytoplasm of Reed-Sternberg cells could be due to in vivo binding and ingestion of immune complexes by such cells. The specificity of the interaction between soluble complement-containing immune complexes and neoplastic cells of Hodgkin's disease depends on the nature of the complexed antigen. The complexes could non-specifically attach via an Fc receptor or, if the complexed antigen is identical to a tumour cell antigen, the binding could be specific. If the immune complexes are tumour specific they could provide a source for isolation and identification of tumour-associated antigens. However, the aetiological significance of antigens and putative oncogenic viruses thus far identified in association with Hodgkin's disease remains to be clarified.

Immunological family studies in Hodgkin's disease. Is the immunodeficiency horizontally transmitted?

27 consanguineous and non-consanguineous relatives to 12 patients with Hodgkin's disease (HD) have been studied. The lymphocyte DNA synthesis induced by concanavalin (ConA) was depressed in 6 patients. 7 out of 15 tested relatives (3 first degree relatives and 4 spouses) showed a profound impairment in lymphocyte response to ConA stimulation. None out of 12 relatives to ConA normal patients was defect in this respect. In relatives to ConA hyporesponsive patients there was a small but statistically significant decrease in lymphocyte response to pokeweed mitogen (PWM) and PPD in vitro. No differences in lymphocyte subpopulations were seen. The findings strongly support an exogenous factory (probably a virus) causing the depressed mitogen response in relatives to immunodeficient patients with HD. A possible linkage between the immunodeficiency and the pathogenesis of HD is discussed.

Immunological defects in healthy twin siblings to patients with Hodgkin's disease

We studied the immunocompetence of 6 healthy twins, whose monozygotic or dizygotic same-sexed twin partner had died from Hodgkin's disease. Lymphocyte DNA synthesis induced by concanavalin A was markedly reduced at 3 different concentrations in all twins compared to an age-matched group of healthy controls. The lymphocyte response to pokeweed mitogen and to phytohaemagglutinin was also impaired. PPD induced lymphocyte DNA synthesis was low in 3 twins and correlated well with their delayed skin hypersensitivity to the antigen. One twin was completely anergic to 3 different skin antigens. The mean total blood lymphocyte count did not differ from that of controls. There was no change in T or B-lymphocyte subpopulations. The presence of a functional lymphocyte deficiency in all twins strongly suggests that the immunodeficiency in Hodgkin's disease is partly caused by genetic and/or environmental factors.