GERMINAL CENTER CHANGES AND PLASMA CELL REACTION DURING THE PRIMARY IMMUNE RESPONSE

Histological, immunohistological and autopsy findings in lymphogranulomatosis X (including angio-immunoblastic lymphadenopathy)

172 cases of lymphogranulomatosis X (LgX) were studied by light microscopy. In 53 cases immunohistological techniques for detecting intracytoplasmic immunoglobulins were applied. In the lymph nodes of all cases the nodal architecture was found to be effaced. Active germinal centres were absent, and there was a generalized, markedly increased proliferation of epithelioid venules. A polymorphic infiltrate was present in all cases. It was dominated by immunoblasts in 14%, by plasma cells in 16%, by epithelioid cells in 23% and by lymphocytes in 6% of the cases. In the remaining 41% of the cases no special type of cell predominated (mixed cell type of LgX). The clusters of clear cells present in some cases with immunoblastic predominance did not stain for intracytoplasmic immunoglobulins; in contrast, the basophilic immunoblasts exhibited a polyclonal Ig pattern. In some of the cases with lymphocytic predominance most of the lymphocytes showed abundant cytoplasm with azurophil granules. Transformation into malignant lymphoma was proven at autopsy in 5 of 38 cases (13.2%). Malignant transformation (biopsy and autopsy material) was confirmed in a total of 11 of 172 cases (6.4%) and suspected in an additional 7%. Among the malignant lymphomas were one immunologically proven B-immunoblastic lymphoma, one peripheral T cell lymphoma and 5 cases of Hodgkin's disease. An association between LgX and carcinoma was histologically verified in 7 cases. 26 cases with active germinal centres and 11 cases with only locally pronounced vascularization but with histological and cytological changes that were otherwise similar to LgX were designated as hyperimmune reactions (HR). These cases had a significantly better prognosis. Two cases that presented as HR with active germinal centres later developed into LgX. It is suggested that the disappearance of active germinal centres is important in the pathogenesis of LgX. The possibility that this may correspond morphologically to an alteration of different components of the T-cell system is discussed.

Massive increase in splenic germinal centres of chickens experimentally-infected with Trypanosoma brucei brucei

Domestic chickens infected with Trypanosoma brucei brucei developed a latent parasitaemia which lasted for one year. Six distinct variable antigen types were isolated. Spleens from infected birds were studied histologically at different stages of the infection. Trypanosome infection produced a progressive increase in the number of germinal centres during the early stages of the infection. Peak numbers of germinal centres were reached in the spleen at Day 84 after which the numbers were maintained during an active infection. A tenfold increase in the number of germinal centres was found in trypanosome-infected birds compared to controls. No splenomegaly was observed. Lymphoid cells of the caecal tonsil and the thymus remained apparently normal during the course of infection. Chemotherapeutic termination of infection with berenil resulted in an initial increase in the number of germinal centres. A gradual return to normal level was observed on Day 100 post cure. It is suggested that the development of such a large number of germinal centres reflects the bird's response to the elaboration of a succession of trypanosome variable antigens.

Morphology of the spleen in women who died of metastatic genital tract cancer

The histology of the white pulp of the spleen was assessed in 56 women who died of metastatic genital tract cancer and in 56 age-matched women who died of a myocardial infarction or a stroke. Special attention was paid to the areas associated with T cells and B cells. The T-cell and B-cell areas were profoundly depleted in patients with carcinoma. This suggests that women who die of genital tract cancer have impaired humoral and cell-mediated immunity.

Morphology of the spleen white pulp in relation to the immunological functions in patients with far advanced bronchial carcinoma

The white pulp of the spleens collected from seventy-nine patients died in far advanced bronchial carcinoma, and the same number of spleens from an age-matched group of patients died in myocardial infarction without evidence of any malignancy was histologically assessed by using a standardized reporting system recently introduced by the author. Emphasis was placed on the evaluation of the cell populations involved in immunological reactions. Histological characteristics suggesting an active function of both the cell-mediated and humoral immune reactions (T- and B-cell areas) were found to be within normal limits in the control series, but profoundly deranged in the cancer patients. Active germinal centers were infrequently seen in both series. The significance of the histological observations made was discussed in the light of the impaired immunological reactivity associated with human malignancies, and a conclusion was drawn, although with some caution, that such an impairment of both the humoral and cell-mediated immune responses might probably exist in a considerable number of the present patients dying of far advanced bronchial carcinoma. The applicability of the reporting system now used for the first time in human pathology was emphasized.

Spleen white pulp morphology as an indicator of the immunological state in DBA/2 mice bearing mastocytoma

The morphology of the spleen white pulp in DBA/2 mice bearing the chemically induced mastocytoma, P-815-X2, was evaluated by using the standardized reporting system previously introduced to describe the spleen morphology in relation to immunological functions. Special emphasis was placed on the assessment of the T- and B-lymphocytes, the appropriate functions of which have previously been proposed to be affected by the tumor concerned. When compared with the control mice, both the central perarterial lymphoid sheaths (C-PALS) and peripheral periarterial lymphoid sheaths (P-PALS) T- and B-cell areas, respectively, were seen to be altered in a way suggesting derangement in the function of both these lymphocyte populations, almost exclusively in mastocytoma-bearing mice. The present results, thus, confirm the observations made earlier on the immunosuppressive potentialities of mastocytoma in DBA/2 mice, and the recording system used seems to be a suitable one to be applied in the evaluation of the morphologic manifestations of these immunological functions.

Morphologic and cell kinetic investigations of the spleen after repeated in situ freezing of liver and kidney

In order to evaluate a possible primary or secondary immunologic response of the spleen after single or repeated in situ freezing of parenchymal organs such as liver and kidney within a four week period, light microscopic and cell kinetic investigations with tritiated thymidine were performed on spleens of non-germfree rats. Sham operations served as controls. The sham operations did not induce any significant morphological or cell kinetic changes in the splenic white pulp. After cryolesions were produced in the liver and kidney, the percentages of activated germinal centers, labeled germinal center cells, and cells in the perifollicular area of the lymphatic mantle and marginal zones increased, with maxima during the first 3 days. The investigations show that the cellular reaction of the spleen starts earlier and is more prominent after repeated in situ freezing than after a single cryolesion. These findings point to an immunologic response of the anamnestic type, and correspond to results after repeated freezing of normal and malignant tissue of the urogenital tract. These cell kinetic results are important in the evaluation of further immunologic studies involving the cryotherapy of malignant tissues.

The prognostic significance of pelvic lymph node morphology in carcinoma of the uterine cervix

Pelvic lymph nodes from 80 patients with primary invasive cervical cancer undergoing radical hysterectomy and pelvic lymphadenectomy were evaluated morphologically. Six to 25 (mean 14) lymph nodes from each patient were examined histologically and classified as follows: lymphocyte preominant, germinal center predominant, unstimulated, or lymphocyte depleted. Tumors were classified according to their primary cell type: large cell non-keratinizing, keratinizing squamous cell, small cell, and adenocarcinoma. There was no direct relationship between lymph node morphology and patient age, lesion size, or tumor cell type. A lymphocyte predominant nodal pattern was associated with a statistically significant decrease in lymph node metastases, and tumor recurrence, and an increase in patient survival. In contrast, patients with a lymphocyte depleted nodal pattern had a high incidence of metastatic disease and tumor recurrence, and a decreased survival. Patients with lymph nodes showing an unstimulated or germinal center predominant pattern had an intermediate incidence of nodal metastases and tumor recurrence. These findings suggest that regional lymph nodal morphology may be of prognostic significance in patients with invasive carcinoma of the uterine cervix.

The primary immune response in mice. 3. Retention of sheep red blood cell immunogens by the spleen and liver

The antibody-inducing activities of foreign red blood cell immunogens sequestered in the spleens and livers of mice injected with sheep erythrocytes were evaluated during the early periods of the immune response. Estimates of immunogenicity, obtained from the magnitudes of anti-sheep red blood cell hemolysin responses evoked in sensitized recipient mice by subcellular tissue fractions prepared from these phagocytic organs, showed that the liver and spleen differ greatly in their handling of this particulate antigen. The liver, functioning primarily as a scavenger organ, destroys completely the immunogenicity of the heterologous erythrocytes in 12 hr. In contrast, the spleen handles foreign erythrocyte immunogens in at least two different ways: approximately 90% of the initially sequestered activity is rapidly destroyed by the spleen in 6 hr, but the remaining activity, associated chiefly with a tissue fraction possessing the sedimentation properties of "light mitochondria," is retained at a significant level for 3 days, and then progressively decreases to a low level until the 7th day. A correlation of the observed changes in the properties of the immunogenic tissue fraction with known cellular events in the spleen stimulated by antigens indicates that the retention of the degradable erythrocyte immunogen is essential for stimulating and maintaining immune reactions in this antibody-producing organ.

Localization of immunological complexes fixing beta1C (C3) in germinal centers of lymph nodes

28 human and 60 experimentally stimulated rabbit lymph nodes were studied by means of light microscopy and immunofluorescence. 21 of the 28 human lymph nodes showed well-developed germinal centers. IgM, IgG, and the beta(1C) component of complement were found in the same distribution within germinal centers when examined in serial cryostat sections. 36 rabbits were stimulated with Brucella antigen, and 24 rabbits with BSA. A strikingly consistent correlation between distribution and appearance of specific staining for rabbit beta(1C), IgM, and IgG was observed; when lymph nodes were stimulated with BSA, antigen and specific antibody were present. Treatment of unfixed sections with citrate-buffered saline at low pH resulted in complete elution of immunoglobulins, beta(1C), and BSA from rabbit germinal centers, and in marked diminution of IgG and IgM in human germinal centers, while at the same time plasma cells remained strongly fluorescent. Specific selective fixation of heterologous (human) complement in rabbit germinal centers positive for beta(1C), IgG, IgM, and BSA was also obtained. These data present strong evidence for the existence within germinal centers of antigen-antibody complexes which fix at least the beta(1C) component of complement in vivo. The possibility of complete elution of immunoglobulins from rabbit germinal centers can be taken as evidence that, at least for 20 days after primary and secondary stimulation, a major component of the immunoglobulins present in germinal centers is not produced locally but accumulates at the surface of cells.

Possible host resistance in carcinoma of the breast: a histological study

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The primary immune response in mice. II. Cellular responses of lymphoid tissue accompanying the enhancement or complete suppression of antibody formation by a bacterial endotoxin

The effects of a single injection of a bacterial endotoxin on the cellular changes of a primary immune response to a standard dose of sheep red blood cells were studied in the spleens and mesenteric lymph nodes of mice. Daily histological comparisons of these organs in mice, injected with endotoxin, or with antigen, or both, showed that endotoxin given simultaneously with sheep red blood cells, as antigen, significantly enhanced all of the cellular changes that appear in the mesenteric lymph nodes and spleens of mice that form antibody when that antigen is given alone. First, in the white pulp of the spleens and cortical regions of the nodes, there appeared an early and excessive proliferation of the large pyroninophilic cells which seems to be responsible for the earliest formation of antibody, as judged by this work and that of others cited in the body of the paper. Polymorphonuclear cells invaded the spleens of these animals early after simultaneous challenge with antigen and endotoxin, and in far greater numbers than have ever been seen in mice given the same antigen without endotoxin. "Activated" germinal centers formed in the lymphoid tissue either 1 day before the appearance of antibody in the blood stream or on the same day, and they became larger than in the mice given antigen only. On the other hand, these specific and characteristic cellular changes failed to appear in mice prevented from forming any antibody at all by injections of endotoxin given 2 days before the antigenic challenge. These findings are discussed in the light provided by data from recent reports of others as well as in the light of the accompanying paper (1) which demonstrated not only the enhancement of antibody formation following simultaneous injections of antigen and endotoxin, as already known, but a totally unexpected, complete suppression of its formation when endotoxin was given 2 days before antigen.

Thymus-dependent areas in the lymphoid organs of neonatally thymectomized mice

Specific areas of lymphocyte depletion, termed thymus-dependent areas, have been delineated in neonatally thymectomized C3H/Bi and F(1) (C57BL x C3H/Bi) mice. They occur within the lymphoid follicles of the spleen immediately surrounding the central arterioles, and constitute the mid and deep cortical zones of the lymph nodes. These depleted areas appear in healthy thymectomized mice as early as 3 wk after operation but, in mice which survive for more than 6 to 7 wk, the thymus-dependent areas are repopulated by rapidly dividing pyroninophilic cells, the majority of which are immature plasma cells. Syngeneic thymus cells, labeled in vitro with tritiated adenosine localize preferentially in the thymus-dependent areas after intravenous injection. Similarly labeled spleen cells also accumulate in these areas but, in addition, are distributed at the periphery of splenic follicles and in the outer cortical zone of the lymph nodes. Many more spleen than thymus cells enter the lymphoid tissues and the spleen appears to be the primary target. The apparent paradox that syngeneic thymus cells are less efficient than spleen cells in restoring neonatally thymectomized mice to normality is discussed in the light of these results and possible routes by which the migrating cells could enter the lymphoid tissues are considered. The origin of the plasma cells which repopulate the lymphocyte depleted areas is also discussed. It is concluded that the normal thymus produces cells which contribute directly to the migratory or circulatory lymphocyte population but that there also exists another source of supply for the plasma cell series. These two systems may function synergistically so that the thymus may control, directly or indirectly, the balance of cell populations within the body.