The lymphoid system. Its normal architecture and the potential for understanding the system through the study of lymphoproliferative diseases

How One Thing Led to Another

I started research in high school, experimenting on immunological tolerance to transplantation antigens. This led to studies of the thymus as the site of maturation of T cells, which led to the discovery, isolation, and clinical transplantation of purified hematopoietic stem cells (HSCs). The induction of immune tolerance with HSCs has led to isolation of other tissue-specific stem cells for regenerative medicine. Our studies of circulating competing germline stem cells in colonial protochordates led us to document competing HSCs. In human acute myelogenous leukemia we showed that all preleukemic mutations occur in HSCs, and determined their order; the final mutations occur in a multipotent progenitor derived from the preleukemic HSC clone. With these, we discovered that CD47 is an upregulated gene in all human cancers and is a "don't eat me" signal; blocking it with antibodies leads to cancer cell phagocytosis. CD47 is the first known gene common to all cancers and is a target for cancer immunotherapy.

Somatic mosaicism: on the road to cancer

Diversity is the basis of fitness selection. Although the genome of an individual is considered to be largely stable, there is theoretical and experimental evidence--both in model organisms and in humans--that genetic mosaicism is the rule rather than the exception. The continuous generation of cell variants, their interactions and selective pressures lead to life-long tissue dynamics. Individuals may thus enjoy 'clonal health', defined as a clonal composition that supports healthy morphology and physiology, or suffer from clonal configurations that promote disease, such as cancer. The contribution of mosaicism to these processes starts during embryonic development. In this Opinion article, we argue that the road to cancer might begin during these early stages.

Use of muscarinic agonists in the treatment of Sjögren's syndrome

Two muscarinic agonists (pilocarpine and cevimeline) have recently been approved for the treatment of symptoms of xerostomia in Sjögren's syndrome (SS). These agents stimulate the M1 and M3 receptors present on salivary glands, leading to increased secretory function. The use of these agents emphasizes the importance of neuroendocrine mechanisms in SS, which is considered an autoimmune disorder. We review recent studies on the release of cytokines and metalloproteinases in SS-affected glands and their influence on the release of and response to neurotransmitters. Also, we review the structure and function of muscarinic receptors as they may relate to SS and the potential use of novel muscarinic agonists in SS.

The follicular non-Hodgkin's lymphomas--I. The possibility of cure

The follicular lymphomas pursue an indolent course in many patients. Long-term follow-up in large series is therefore necessary to establish whether cure is taking place, and if so, at what stage in the dissemination of the disease process it becomes unlikely. The time to, and site of relapse, together with its impact on survival has been studied in 398 patients entered into the British National Lymphoma Investigation limited and disseminated disease trials between 1974 and 1980. Relapse data were compared with various models to obtain maximum likelihood estimates of the proportions permanently remaining relapse-free following treatment. Long-term relapse-free survival was observed in 54.8 +/- 14.9% (95% CI) of patients at 15 years with Ann Arbor stage I disease, 29.2 +/- 13.6% in patients with stage II disease, 18.1 +/- 6.6% with stage III and 13.0 +/- 5.9% with IV disease. Relapse time-course data for all trial arms conform closely to lognormal distributions allowing maximum likelihood estimates of proportions remaining permanently relapse-free to be derived. Using this methodology, over a quarter of patients treated with involved radiotherapy alone or radiotherapy plus 6 months of chlorambucil in the limited disease (Ann Arbor stage I and II) trial are unlikely to relapse at any time in the future. Over 10% of patients treated in the disseminated disease trials with disease classified as Ann Arbor stage III are also statistically unlikely to relapse. The finding that a proportion of patients is statistically unlikely to experience a clinically obvious relapse is consistent with clinical cure. It is especially interesting that a small proportion of patients with disseminated disease and treated by chemotherapy have fallen into this category, but additional data are required to know at what point statistical cure becomes unlikely. Whether "clinical cure" is the same as "pathological cure" in this disease remains uncertain.

The follicular non-Hodgkin's lymphomas--II. Prognostic factors: what do they mean?

The Ann Arbor staging classification has long been recognised to have shortcomings when used to stage the follicular lymphomas. To date, the identification of important prognostic variables has not succeeded in producing a superior staging classification that reflects the stages of dissemination of these processes in a way that can be used in the testing of new therapeutic strategies. A fresh look is taken at these factors. Data from 398 patients entered into the British National Lymphoma Investigation trials between 1974 and 1980, were analysed to evaluate the performance of the Ann Arbor staging classification. Multiple regression and proportional hazards techniques were used to determine what factors independently influence response to initial treatment, the durability of that response and ultimate survival, and to isolate factors that relate to disease progression from those that have other mechanisms of action. The Ann Arbor staging classification fared poorly, minimally separating relapse-free and cause-specific survival probabilities in patients with the largest staging groupings, III and IV. Significant prognostic heterogeneity was seen in both of these stage groupings, with 22% of patients with stage IV disease on the basis of marrow involvement having slightly better outcomes than patients with stage III disease. Significant differences in outcome were also observed between patients of different age and sex in each Ann Arbor stage grouping. Increasing number of lymph node regions involved, constitutional symptoms, the presence of splenomegaly and increasing age were observed to have powerfully independent adverse influence on probability of complete response to treatment and cause-specific survival. The evolution of the follicular lymphomas is reflected at the clinical level by an increase in the number of lymph node regions involved and splenomegaly. Simple classifications based on simple counts of lymph node regions involved and splenomegaly are more successful than the Ann Arbor staging classification in subdividing the series into patient subgroups that, regardless of gender or age, experience significantly different probabilities of responding completely to therapy and, as a consequence, relapse-free and cause-specific survival expectations. The definition of poor prognosis in subgroups may be of value in selecting patients for newer and more intensive therapeutic approaches.

Sjögren's syndrome: immunologic and neuroendocrine mechanisms

SS patients are characterized by decreased volume of lacrimal and salivary secretions. The dryness results from a combination of destroyed glandular elements as well as by interference with the neuro-endocrine innervation of the residual glands. Specific genetic factors (i.e. HLA class II alleles) have been associated with increased risk of SS in Caucasian (US), Chinese and Japanese populations. However, different class II MHC alleles are risk factors in each population. The environmental factors that precipitate SS remain unknown. Future understanding of the mechanisms of destruction of the salivary and lacrimal glands may provide a more rationale approach to therapy.

Ultrastructural morphometric study of follicular center lymphocytes: I. Nuclear characteristics and the Lukes-Collins' concept

A combined ultrastructural and morphometric image analysis study was carried out on the nuclear profiles of follicular center and mantle zone lymphocytes of six cases of reactive hyperplasia in human lymph node biopsies. For accuracy of morphological observations and sampling at low magnifications, sections were mounted on formvar-covered slot grids. Measurements of nuclear profile features of small (untransformed) lymphocytes in mantle zones served as the standard for a supposed unimodal population in each case. Analysis of nuclear profile area values indicated that during lymphocyte transformation in follicular centers nuclei had a gradual and progressive increase in size and that the sampled nuclear profiles in both the mantle zone and follicular center were unimodal. Lymphocyte nuclear shape (contour index) was a more complex, and likely biologically independent, feature than nuclear area in both the mantle zone and follicular center. Nuclear profile contour indexes of mantle zone lymphocytes were more irregular than suspected and in some cases had mean values greater than those of follicular center lymphocytes. Furthermore, the frequency distribution of nuclear contour index was not normally distributed in either the follicular center or mantle zone due to the presence of a small proportion of highly irregularly shaped nuclear profiles in both sites. The results indicated that some premises of existing concepts of follicular center cells and the process of lymphocyte transformation in follicular centers were incorrect and should not be directly extrapolated to the nuclear profile characteristics in non-Hodgkin's lymphoma.

Histological and immunohistological analysis of human lymphomas

Morphological and immunological characteristics of lymphoproliferative diseases are reviewed. In particular, a basic distinction is made between non-Hodgkin's lymphomas and Hodgkin's disease. As to the non-Hodgkin's lymphomas, emphasis is given to the problems of classification, technical approach, histogenesis, and prognosis. The authors adopt a version of the Kiel Classification modified to take account of new knowledge regarding T-cell lymphomas. The value of immunophenotyping in making an accurate distinction between the various categories is stressed; immunocytochemical detection of the growth fraction is also discussed and then proposed as a new prognostic tool. Finally, the criteria for differential diagnosis between non-Hodgkin's lymphomas, malignant histiocytosis, non-lymphoid large cell tumors, and atypical immune reactions are outlined.

The non-Hodgkin's lymphomas: old and new thinking

Knowledge of non-Hodgkin's lymphomas has increased enormously in the last 10-15 years. The various types are considered to reflect the normal immunological processes that take place in the lymphoid tissue after antigenic challenge. This concept, which states that non-Hodgkin's lymphomas are neoplastic counterparts of normal processes, has implications for morphology, immunology and clinical behaviour. Based on this concept, as well as on immunohistological and functional data, a hypothetical scheme of B-cell development is proposed. The relation to normal physiology also holds for lymphomas localized outside the lymph nodes. Normal structure and function in two important extranodal lymphoid tissues, the gastrointestinal mucosa and the skin-associated lymphoid tissues, are related to the lymphomas arising in these sites. This relation and some of its implications are discussed, with special reference to the important processes of homing and recirculation of lymphocytes.

S-100 protein, fibronectin, and laminin immunostaining in lymphomas of follicular center cell origin

Forty-nine paraffin-embedded biopsy specimens of involved nodal and extranodal tissue (bone marrow, spleen, and liver) from 13 patients with follicular center cell lymphomas (FCCL) and 14 with small lymphocytic lymphomas (SLL), including 11 cases with chronic lymphocytic leukemia, were tested for S-100 protein immunoreactivity. Analysis for fibronectin and laminin immunoreactivities was limited to the lymph node biopsy specimens. In FCCL, S-100-positive dendritic reticulum cells (DRCs) were found in 23 of the 26 tissue specimens examined, regardless of the involved sites and the growth pattern. Cases with completely or predominantly follicular pattern were usually associated with a spherical meshwork pattern of S-100-positive DRCs; in the FCCL specimens with a diffuse pattern (lymph nodes and bone marrow) as well as in the specimen areas with a minimally follicular tumor pattern, S-100-positive DRCs were consistently fewer in number and composed loosely aggregated nests. No S-100-positive DRCs were found in all the biopsy specimens in SLL. Concerning fibronectin and laminin immunostainings, results showed that no differences were present between areas of follicular and diffuse neoplastic growth and that the neoplastic growth of FCCL maintained for each antiserum the same distribution pattern as that seen in normal follicles. Analysis of the microenvironmental components as revealed with antisera used in the current study--particularly with anti-S-100 protein antiserum--appears to be a useful adjunct for the identification of FCCL in paraffin-embedded biopsy specimens, especially in extranodal sites.

Mouse x human heterohybridomas as fusion partners with human B cell tumors

Surface idiotype (Id) of B cell malignancies is an excellent tumor-specific marker. We have, however, recently described heterogeneity of tumor Id in some cases. We therefore sought a way to isolate, reliably and efficiently, different species of idiotype from a potentially heterogeneous population. In this report we demonstrate our success using a series of mouse X human heterohybridomas as fusion partners with human B cell tumors. Three lines (K6H6/B5, K6H9/G12, SBC/H20) demonstrated excellent fusion efficiency with 75%-85% of wells plated containing hybrids. Two cell lines, K6H9/G12 and SBC/H20 had a tendency to secrete a single Ig chain (heavy or light chain), whereas the K6H6/B5 cell line secreted whole immunoglobulin (Ig) in greater than 80% of the hybrids. This line secreted significant amounts of Ig (2.73 micrograms/ml/10(6) cells) and was relatively stable in culture. Since this line has such a high fusion efficiency the products of normal B cells admixed with tumor may be recovered, allowing the opportunity of isolating host anti-tumor antibodies. In order to prove that hybrids were derived from the tumor, Southern blot analysis of rearranged DNA was performed in selected cases. Fusions with this line provide the potential for recovering many different species of idiotype in a mixed population. This will facilitate the production of mouse monoclonal anti-idiotype antibodies against many variants and against different idiotopes.

Signet ring cell lymphoma of the thyroid: a case report

The first case of extranodal signet ring cell lymphoma involving the thyroid gland is reported in a 53-year-old woman with Hashimoto's thyroiditis. Since 1978, 24 cases of signet ring cell lymphoma, all involving primarily nodal tissue, have been documented in the literature. This rare neoplasm is believed to be a variant of non-Hodgkin's follicular lymphoma, which may be mistaken for metastatic poorly differentiated adenocarcinoma.

B-cell neoplasms of the lymphocytic, lymphoplasmacytoid, and plasma cell types: immunohistologic analysis and clinical correlation

The relation between chronic lymphocytic leukemia (CLL, lymphocytic lymphoma (SL), plasmacytoid lymphocytic lymphoma (LP), plasmacytoma (PL), and multiple myeloma (MM) was investigated with cryostat sections stained with antibodies to immunoglobulin heavy and light chains and the B-cell differentiation antigens B1, B2, Ia, T1, and CALLA. Neoplasms were subclassified according to plasmacytoid features, leukemia (CLL) site of involvement (nodal or extranodal), serum monoclonal immunoglobulin, or clinical evidence of MM. The results defined two groups of lymphocytic lymphomas without plasmacytoid features (16 cases). Ten of these lymphomas were associated with CLL. Nine involved lymph nodes, all expressed IgM, five expressed IgD, nine were B2-positive, eight were T1-positive, and all were B1- and Ia-positive. Six of the lymphomas were not associated with CLL. Five of these tumors were extranodal, all were T1- B1+ B2- Ia+, five expressed IgM without IgD, and one contained IgG. These differences in clinical and immunologic phenotypes suggest that CLL and SL without CLL may be related to different stages of B-cell differentiation. T1 appeared to be a marker for CLL, since all T1-positive neoplasms were leukemic. Lymphomas with plasmacytoid features (ten cases) were more often extranodal, and none was leukemic. The immunologic phenotypes were heterogeneous: all of these lymphomas were T1-negative, most were IgM+ IgD-, three were B2-positive, and all were Ia-positive. The plasma cells in five lymphomas with marked plasmacytoid features were B1-negative; they were Ia-positive in four and Ia-negative in one. These data suggest that LP is a heterogeneous group, reflecting B cells at diverse stages of differentiation. Ten plasmacytomas, nine of which were associated with MM, differed from LP in showing heavy chain class switching; all were T1- B1- B2-, and all but one were Ia-negative. These results are consistent with the existence of two pathways or stages of B-cell differentiation: one that generates IgM-producing plasma cells, as seen in the primary immune response or in response to pokeweed mitogen, and one that generates IgG- or IgA-positive plasma cells, as seen in the late primary or secondary immune response. Plasmacytoid lymphocytic lymphoma reflects the first, while PL/MM reflects the second pathway. B1 appears to be lost before Ia in terminal plasma cell differentiation.

Immunophenotype of lymphoid cells in positive patch tests of allergic contact dermatitis

The immune phenotype of the infiltrating cells in 13 positive patch tests from 8 cases of contact dermatitis and 1 case of poison ivy was studied. An indirect immunoperoxidase technique was used in conjunction with monoclonal antibodies directed against mature T cells (Leu-1, T11), helper T cells (Leu-3A), suppressor/cytotoxic T cells (Leu-2A), killer and natural killer cells (HNK 1), B cells (B1), Langerhans cells (HLA-DR), and the common acute lymphoblastic leukemia antigen (CALLA), (J5). The majority of infiltrating mononuclear cells were Leu-1+, T11+, Leu-3A+, Leu-2A-, HLA-DR+, T9-, T10-, HNK-, B1-, J5-. Occasional T6+ cells were observed in the epidermis (including spongiotic microvesicles) and also isolated in the dermis and within the dermal mononuclear infiltrates. The phenotype was compared with cutaneous T-cell lymphoma, a disease in which contact allergy and antigenic persistence may play a role.

Immunomorphologic and morphometric changes in pulmonary lymph nodes of sheep with progressive pneumonia

Morphologic, immunohistochemical, and morphometric studies were conducted on the posterior mediastinal lymph nodes of eleven sheep with naturally occurring ovine progressive pneumonia and four apparently healthy sheep with no pulmonary lesions (three seropositive, one seronegative for antibody to ovine progressive pneumonia virus). Compared with lesion-free sheep, sheep with ovine progressive pneumonia had a seven-fold increase in B lymphocyte areas and a 21/2-fold increase in T lymphocyte areas of these lymph nodes. Immunochemistry revealed cytoplasmic immunoglobulin G in scattered cells of germinal centers, medullary cords and interfollicular areas and membrane-associated immunoglobulin G in dendritic cells of germinal centers. Immunoglobulin M staining cells were widely scattered in germinal centers and medullary cords. Although B cell hyperplasia seemed to be the predominant process in lymph nodes of sheep with ovine progressive pneumonia, this was not accompanied by the expected degree of plasmacytosis, morphologically and immunohistochemically. These findings may represent an aberrancy of immunoregulation in ovine progressive pneumonia.

Primary Sjogren syndrome: clinical and immunopathologic features

Primary Sjogren syndrome is an autoimmune condition in which dry eyes (keratoconjunctivitis sicca) and dry mouth (xerostomia) result from lymphocytic infiltration of lacrimal and salivary glands. Clinical and laboratory features of 60 primary Sjogren syndrome patients seen at our clinic during the past three years are presented. These patients illustrate the wide spectrum of extraglandular features that may occur as a result of lymphoid infiltration of lung, kidney, skin, stomach, liver, and muscle. They further emphasize the difficulty in classifying a patient as primary or secondary Sjogren syndrome (ie, sicca symptoms associated with systemic lupus erythematosus, rheumatoid arthritis, or scleroderma), particularly early in the disease course. As an initial step in understanding the pathogenesis, the lymphocytes that infiltrate the salivary glands and lymph nodes were characterized by using monoclonal antibodies that recognize distinct lymphocyte subsets and by using in vitro functional assays. These studies have demonstrated that affected tissues have infiltrates of T cells with helper/inducer activity and with a high frequency of "activation antigens." The immunohistologic techniques are useful in differentiating "benign" and "pseudolymphoma" lesions (both due predominantly to T cells) from non-Hodgkin lymphoma (usually due to B-cell infiltrates). Although there is no "cure" for primary Sjogren syndrome patient's symptoms may be significantly improved by measures aimed at prevention of ocular and dental complications and by the recognition of extraglandular features that may be amenable to specific treatment.

Characterization of immature sinus histiocytes (monocytoid cells) in reactive lymph nodes by use of monoclonal antibodies

The distinctive mononuclear cells that appear in the cortical sinuses of lymph nodes in toxoplasma lymphadenitis and other conditions have been termed "immature sinus histiocytes," although these cells have neither enzyme histochemical nor ultrastructural features of histiocytes. The authors stained these cells in frozen sections of six reactive lymph nodes, using the immunoperoxidase technique, with monoclonal antibodies to T cell, B cell, and monocyte antigens and with heteroantisera to immunoglobulin and lysozyme. The immature sinus histiocytes stained with a monoclonal antibody to B cells (anti-B1) and had immunoglobulin of the IgG class. They did not react with monoclonal antibodies to T cells or monocytes or with antilysozyme. In contrast, medullary sinus histiocytes in three additional lymph nodes were B1-negative and reacted with anti-T4, anti-M1, and anti-lysozyme. These results indicate that immature sinus histiocytes are IgG-bearing B lymphocytes rather than histiocytes. Their role in the immune response remains enigmatic.

Lymphocyte subsets in the white pulp of human spleen in normal and diseased cases

The distribution of T and B lymphocytes and their subsets in the white pulp of human spleens extirpated from patients with cancer of the digestive tract and those with portal hypertension was examined with the appliance of monoclonal antibodies. T lymphocytes were distributed in the core of lymphatic sheath protuberance (Matsumoto), while the mantle zone of lymphatic nodule and germinal center were solely occupied by B lymphocytes. On the other hand, both T and B lymphocytes were found in the cortical zone of lymphatic sheath protuberance and outer and inner layer of lymphatic nodule. The ratio of both cells differed from one case to the other. The majority of T lymphocytes in the core of lymphatic sheath protuberance and those localized in the light region of germinal center were helper T cells. Although the lymphatic sheaths in cases with portal hypertension were narrower than those in the controls, there was no difference in the distribution density of T cells between the two groups. Hardly any B lymphocytes were found in the cortical zone of lymphatic sheath protuberance, while the mixture of T lymphocytes tended to become prominent in the outer and inner layer of lymphatic nodule in those cases.

Visceral leishmaniasis in the German shepherd dog. II. Pathology

Three German shepherd dogs were inoculated with Leishmania chagasi and three with Leishmania donovani and the infection was followed for 82 days. All infected dogs developed splenomegaly and lymphadenomegaly. In lymph nodes there was a reduction in lymphocyte population in paracortical areas, extensive proliferation of macrophages in paracortical areas and medullary cords, follicular hyperplasia, and increased numbers of plasma cells. The spleen had decreased numbers of lymphocytes in periarteriolar lymphoid sheaths, proliferation of macrophages in these regions, follicular hyperplasia, and enlargement of the red pulp with clusters of macrophages and plasma cells. The morphology of the tonsil was similar to the lymph nodes. Clusters of macrophages, often containing Leishmania spp, were present in liver, bone marrow, lung, and the intestines. The morphologic changes in lymph nodes and spleen were suggestive of a suppressed cell-mediated immunity and an active humoral immunity. The German shepherd dog may be a useful laboratory model for the study of immunopathologic changes in visceral leishmaniasis.

Rat splenic D-T diaphorase and NAD(P)H-nitroblue tetrazolium reductase. Their use to assess the action of polycyclic hydrocarbons in the lymphatic system

The biochemical response of rat splenic D-T diaphorase and the histochemical distribution of the enzyme NAD(P)H-NBT reductase to the action of the polycyclic hydrocarbons benz(a)pyrene, 3-methylcholanthrene, 7,12-dimethylbenz(a)anthracene and benz(a)anthracene have been studied. The four polycyclic hydrocarbons tested in this work induced the activity of both enzymes. The stimulation of the D-T diaphorase by benz(a)pyrene is dose dependent and it is partially inhibited by dicumarol. Microsomal and mitochondrial NAD(P)H dehydrogenases are not induced by any of these compounds. The study of the histochemical distribution of the NAD(P)H-NBT reductase shows also a marked increase in the staining of the enzyme which follow a specific pattern, the cells showing the highest activity are the lymphocytes located around the marginal sinus of the white pulp and around follicular arterioles, plus red pulp lymphocytes and myeloblastic cells. The cells in the germinal center show from null to very weak activity. A correlation between the biochemical induction of the soluble D-T diaphorase of the histochemical increase of the NAD(P)H-NBT reductase is attempted.

Lymph node reactions to cancer

Histological, histomorphometrical and histochemical data on the response of regional lymph nodes to tumor development, as recorded in experimental and clinical studies, were coordinated and supplemented by recent findings in experimentally induced autochthonous carcinomas in the rat gastrointestinal tract. The attempted correlation led to the definition of several prognostic parameters: 1) The development of germinal centers and the plasmocytic reaction in tumor draining nodes are morphological expressions of active humoral immune responses that may be specifically directed against the tumor. These reactions attain their maximum usually during late stages of tumor development. Their incidence and prognostic significance may vary depending upon the stage and the type of tumor. 2) Sinus histiocytosis is an immunologically nonspecific lymph node response with debatable prognostic significance. 3) Granulomatous sarcoid-like lesions may be understood as signs of an immunologically mediated antitumor response of macrophages activated by T lymphocytes. They are indicative of a favorable prognosis. 4) Paracortical hyperplasia, characterized by an increased population of lymphocytes and eventually immunoblasts, is an expression of an active T-cell reaction. This reaction occurs typically during early stages of experimental tumors. Correspondingly, it is of favorable prognostic significance in human tumors. 5) Lymphocytic depletion and nodular alteration of T-cell areas, with increased histiocytic infiltration, are reactions most often seen in the draining nodes of an advanced tumor. Both seem to coincide with depression of the cell-mediated immune reactivity. The present assessment of the reactive behavior of diverse lymph node compartments may serve as a first pointer to the proposed histologic immunostaging of malignant tumors.

Immunological and histochemical techniques in the study of the malignant lymphomas: a review

Current methods of immunological and enzymatic marker studies used in the investigation of the malignant lymphomas are reviewed and the application of such methods is demonstrated by illustrative examples. The reliability of the various techniques and their relevance to a modern diagnostic laboratory are discussed.

Immunohistologic studies of cytoplasmic immunoglobulins in rheumatic diseases including two patients with monoclonal patterns and subsequent lymphoma

Tissue specimens from five patients with rheumatic disease who developed lymphadenopathy were studied by an immunoperoxidase method; available biopsy material was examined for cytoplasmic immunoglobulin determinants. Three patients had follicular hyperplasia of lymph nodes with polyclonal patterns. Two patients with Sjogren's syndrome had monoclonal patterns; both of these patients subsequently developed lymphoma with similar monoclonal patterns. Implications of the monoclonal patterns with regard to the biology of these lymphoproliferative disorders are discussed.

Sclerosis in diffuse histiocytic lymphoma: a clinicopathologic study of 25 cases

Sclerosis was observed in the lymph node specimens of 26 of 57 (46%) patients with diffuse histiocytic lymphoma. Two major types of sclerosis was observed: "compartmentalizing" (56%), in which the tumor was divided into many small compartments by anastomosing, hyalinized stroma; and "diffuse" (44%), in which the sclerosis occurred without evident partitioning of the tumor. The hyalinized stroma of the compartmentalizing sclerosis was frequently continuous with small vessels accompanied by aggregates of small lymphocytes, suggesting that the sclerosis was related to the occurrence of small lymphocyte-associated postcapillary venules. Compartmentalizing sclerosis was further divided into two groups: The first group (even pattern) was characterized by an orderly occurrence of the stromal network with no evidence of distortion, evenly spaced tumor cells showing no axis in their arrangement, and a sharp demarcation of tumor cells from the stroma. The second group (uneven pattern) was marked by either a disorderly occurrence of the stromal network with distortion of the overall pattern, tumor cells arranged along an axis, or poor demarcation of tumor cells from the stroma with individual envelopment of tumor cells by the stroma. Approximately two-thirds of the patients (9/14) with the compartmentalizing sclerosis survived two years or more after diagnosis; most patients (10/11) with diffuse sclerosis died within two years. Compartmentalizing sclerosis, even pattern, was associated with a consistently favorable prognosis; the uneven pattern was not. This study indicates a marked variation in the survival of patients with diffuse histiocytic lymphoma with sclerosis and demonstrates that prognostic subgroups may be delineated by additional morphologic features.

[Functional significance of reactive histologic changes in lymph nodes (author's transl)]

Being a reservoir of lymphocytes and plasma cells the lymph nodes are an integral part of the immune system. B and T lymphocytes in the lymph nodes show a distinct topographical distribution. The follicular outer cortex and the medullary cords are predominantly populated by B cells. The paracortical zone between cortex and medulla, is again subdivided in T cell areas and regions with heterogeneous populations of T and B lymphocytes. Even in the normal state nodal lymphocytes maintain a permanent exchange with blood lymphocytes via the mechanism of lymphocyte recirculation. Reactive structural changes of immunologic origin result in an increased immigration of blood lymphocytes into, as well as in local clonal proliferation within the lymph nodes. Four different morphologic patterns of nodal reaction can be determined in terms of functional impact: (1) cortical plasma cell reactions, (2) paracortical plasma cell reactions, (3) germinal center reactions, all three associated with humoral immune responses, and (4) hyperplastic changes of the paracortex associated with cell-mediated immune reactions. In both humoral and cell-mediated immune responses there may be an additional sinus histiocytosis, or mast cell hyperplasia.

T system immunodeficiencies in infancy and childhood

Some problems concerning the diseases due to deficiencies of the T immune system in infancy and childhood are reviewed. The relationships between SCID and Nezelof syndrome and the pathogenesis of this group of diseases are particularly discussed.

Signet ring cell lymphoma: a case report

The authors report a case of signet ring cell lymphoma, a rare variety of germinal (follicular) centre cell neoplasm. It clinical, histological and ultrastructural findings are compared with those of the nine cases previously described. Original immunocytochemical results are presented and discussed.

A study of surface markers in non-Hodgkin's lymphoma by using anti-T and anti-B lymphocyte sera

Cell surface markers of 44 cases of non-Hodgkin's lymphoma (NHL) were studied with various surface markers, especially by using antihuman B lymphocyte serum (ABS), antihuman thymocyte serum (ATS-T), and antihuman peripheral T lymphocyte serum (ALS-T), which were rendered specific for human B lymphocytes, human thymocytes, and human peripheral T lymphocytes, respectively. An immunofluorescent study with ABS, ATS-T, and ALS-T enabled us to demonstrate the histologic localization of normal or neoplastic B and T cells in preserving the original structure of lymphoid organs or tumor tissues. The proportion of cell types in NHL was B cell type 59%, T1 (ATS-T reactive) type 7%, T2 (ALS-T reactive) type 23%, and Null (non T, non B) type 11%. The relationships among cell types, histologic findings, and clinical characteristics were also investigated. Patients with T1-NHL had mediastinal tumors, which were histologically classified into "Lymphoblastic lymphoma." These facts suggest that T1-NHL may have originated in the thymus. Patients with T2-NHL showed a high incidence of skin lesions. Median survival of ten patients with T1- and T2-NHL was seven months, which was much shorter than that of B- or Null-NHL.

Tridimensional study of the deep cortex of the rat lymph node. I: Topography of the deep cortex

Diagrams of the lymph node currently represent its deep cortex (paracortex) as a layer of rather uniform thickness underlying the whole peripheral cortex. However, this concept has not been supported by actual observations; previous investigators have observed, instead, related structures whose appearance varied greatly from nodule-like to ill-defined components. Clearly, the present knowledge of the histology of the deep cortex is inadequate and confusing. Therefore, we undertook a tridimensional study of the region in different nodes of rats. The present work, bearing on the topography of the region, revealed that the deep cortex of the rat node is formed of one to several basic "units." Each unit is a semi-rounded structure, varying from semispheric to semi-ovoid in shape and contiguous to a portion of peripheral cortex. The work further showed that two to several units can fuse to form a "complex." The data indicated that the number, the size and the shape of the units and/or of the complexes of a node differ to some extent according to its anatomical location. These differences probably reflect corresponding variations in the nature and importance of the antigenic stimulation in the different sites of the organism. Finally, the study demonstrated the necessity of tridimensional examination of a node to obtain adequate information on its overall architecture and, particularly, on its deep cortex topography.

Differential diagnosis of malignant lymphoma and nonlymphoid tumors using monoclonal anti-leucocyte antibody

Pathologic samples from 34 cases of human solid malignancies were tested for reactivity with monoclonal anti-human leucocyte antibody, designated 2D1. This antibody detects a human leucocyte antigen (HLe-I) that is expressed strongly on B and T lymphoid cells and weakly on early hemopoietic cells, but is not found on normal mesenchymal and epithelial tissues. This study demonstrates the use of this reagent in cryostat sections of tumor samples using indirect immunofluorescence in combination with other lymphoid markers such as anti-T cell serum, anti-Ia-like serum (detecting p28, 33 "B cell associated" membrane antigen) and antisera to different immunoglobulin isotypes. Tumor cells from all 12 cases of epithelial malignancies and sarcomas were HLe-I- although adjacent (normal) lymphoid cells showed strong positive staining. In contrast, 20 cases of lymphoma (B- as well as T-cell types) were HLe-I+. Two other malignancies involving the lymphoid system were HLe-I- and failed to express any of the other lymphoid markers tested.

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.

Immunologic phenotype in 30 patients with diffuse large-cell lymphoma

Frozen sections of 30 diffuse large-cell ("histiocytic") lymphomas that had arisen in both nodal and extranodal sites were stained with immunoglobulin light-chain and heavy-chain reagents, with nonoclonal antibodies to THAT HAD ARISEN IN BOTH NODAL AND EXTRANODAL SITES WERE STAINED WITH IMMUNOGLOBULIN LIGHT-CHAIN AND HEAVY-CHAIN REAGENTS, WITH MONOCLONAL ANTIBODIES TO T and B-cell antigens, and with an esterase marker for macrophages. Fourteen lymphomas expressed immunoglobulin light chains and were shown to be monoclonal; F(ab')2 fragments were sometimes necessary to demonstrate their monoclonal nature. Mu (IgM) was the most frequently expressed heavy chain, but in many patients other heavy chains were found. None of the lymphomas stained with T-cell antibodies or the esterase; 15 did not stain for immunoglobulin, but 13 of these 15 did express Ia antigen. These immunologic markers identified eight different phenotypes. Retrospective clinical analysis of the patients suggested that those who were immunoglobulin-positive had more advanced disease and shorter survival, but confirmation of the clinical relevance of immunologic phenotype will require prospective studies.

Round cells of the epidermis: clues from studies on neoplastic lymphocytes of cutaneous T cell lymphoma

Neoplastic cells of cutaneous T cell lymphoma (CTCL) appear to be of monoclonal origin and frequently are nonspecific helpers of normal B cell differentiation. A natural progression from epidermotropic (mycosis fungoides and Sézary syndrome) to nonepidermotropic, more widely disseminated T cell neoplasms generally occurs. Affinity of CTLC cells for the epidermis may result from their having membrane receptors for histocompatibility (Ia) antigens present in skin. Cultured human epidermal cells produce a thymopoietin-like molecule, an indication of a role for skin in T cell differentiation.

Spleen white pulp morphology in evaluation of immunologic reactivity of patients with widespread colorectal carcinoma

The morphology of the white pulp of spleens collected from 41 patients who died from widespread adenocarcinoma of the colon and rectum was histologically assessed by using a standardized reporting system previously introduced. As a control, material from the same number of age- and sex-matched patients who died from myocardial infarction with no signs of malignancy was used. Special emphasis was placed on evaluation of the cell population responsible for immunologic reactions. Histologic characteristics suggesting an active function of both the cell-mediated and humoral immune reactions were found to be within normal limits in the control series, whereas in the carcinoma series both these elements were profoundly deranged. The significance of the histologic observations made is discussed in the light of the previously demonstrated immunologic reactions against the cells of human colorectal carcinomas, and a conclusion is drawn that an impairment of both the humoral and cell-mediated immune responses must exist in patients dying from widespread adenocarcinoma of the colon and rectum.

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 architecture in the assessment of immunity in patients with far-advanced pancreatic carcinoma

The histological changes in the white pulp of the spleens collected from 63 patients who had died of widespread adenocarcinoma of the pancreas were assessed by a standardized reporting system. As control material served the same number of age- and sex-matched patients who had died of myocardial infarction without signs of any malignancy. Special attention was focused on the evaluation of the lymphocyte populations (T- and B-cell areas) responsible for immunological reactivity. Histological characteristics suggested to reflect the activity of both cell-mediated and humoral immune responses were within normal limits in the control patients, whereas in the carcinoma series both the T- and B-cell areas were profoundly depleted. The results were interpreted, although with caution, to suggest that some degree of impairment of both humoral and cell-mediated immunity probably exists in patients dying of widespread carcinoma of the pancreas.

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.