The cellular content of non Hodgkin lymphomas: a comprehensive analysis using monoclonal antibodies and other surface marker techniques

Nanotechnology for enhanced nose-to-brain drug delivery in treating neurological diseases

Despite the increasing global incidence of brain disorders, achieving sufficient delivery towards the central nervous system (CNS) remains a formidable challenge in terms of translating into improved clinical outcomes. The brain is highly safeguarded by physiological barriers, primarily the blood-brain barrier (BBB), which routinely excludes most therapeutics from entering the brain following systemic administration. Among various strategies investigated to circumvent this challenge, intranasal administration, a noninvasive method that bypasses the BBB to allow direct access of drugs to the CNS, has been showing promising results. Nanotechnology-based drug delivery systems, in particular, have demonstrated remarkable capacities in overcoming the challenges posed by nose-to-brain drug delivery and facilitating targeted drug accumulation within the brain while minimizing side effects of systemic distribution. This review comprehensively summarizes the barriers of nose-to-brain drug delivery, aiming to enhance our understanding of potential physiological obstacles and improve the efficacy of nasal delivery in future trials. We then highlight cutting-edge nanotechnology-based studies that enhance nose-to-brain drug delivery in three key aspects, demonstrating substantial potential for improved treatment of brain diseases. Furthermore, the attention towards clinical studies will ease the regulatory approval process for nasal administration of nanomedicines targeting brain disease.

Flow cytometric analysis of immunoglobulin heavy chain expression in B-cell lymphoma and reactive lymphoid hyperplasia

The diagnosis of B-cell lymphoma (BCL) is often dependent on the detection of clonal immunoglobulin (Ig) light chain expression. In some BCLs, the determination of clonality based on Ig light chain restriction may be difficult. The aim of our study was to assess the utility of flow cytometric analysis of surface Ig heavy chain (HC) expression in lymphoid tissues in distinguishing lymphoid hyperplasias from BCLs, and also differentiating various BCL subtypes. HC expression on B-cells varied among different types of hyperplasias. In follicular hyperplasia, IgM and IgD expression was high in mantle cells while germinal center cells showed poor HC expression. In other hyperplasias, B cell compartments were blurred but generally showed high IgD and IgM expression. Compared to hyperplasias, BCLs varied in IgM expression. Small lymphocytic lymphomas had lower IgM expression than mantle cell lymphomas. Of importance, IgD expression was significantly lower in BCLs than in hyperplasias, a finding that can be useful in differentiating lymphoma from reactive processes.

Soluble transferrin receptor and iron status in elderly patients

The measurement of soluble transferrin receptor (sTfR) has been proposed as a novel approach to the diagnosis of iron deficiency, especially in anaemia of chronic diseases (ACD). Our aim was to study the utility of sTfR under 'everyday conditions' as seen in a geriatric hospital in the following groups of patients: First, in a pilot group of 99 multimorbid geriatric patients (85 women, 14 men; 82.00 +/- 6.32 years) admitted for rehabilitation after recent surgical treatment of a bone fracture; second, in 677 geriatric patients (506 women, 171 men; 79.17 +/- 11.47 years) with different diagnoses admitted to a department of internal medicine; third, in some remarkable clinical cases in order to illustrate the diagnostic limits of sTfR. In general, both genders showed a remarkable age-dependent decrease in erythropoiesis. In patients with haemoglobin levels below 12.0 mg/dL, this parameter correlated significantly with sTfR. However, this was seen only in women, not in men. Moreover, an age-dependent increase in sTfR was seen in women, while in men it remained almost constant. Based on these findings, we conclude that there is a different, gender-specific aetiology of iron deficiency in the elderly. About 30% of patients of both genders simultaneously had low haemoglobin levels and low sTfR. This was interpreted as 'adaptation' or 'tolerance' to the iron deficiency. This was illustrated by a clinical case of megaloblastic anaemia: Initially low sTfR rose only during the vitamin B12 substitution and normalized after recovery. We conclude that sTfR provides an insight into the 'dynamics' of iron metabolism: A rise in sTfR indicates an 'acute readiness to refill iron stores', while a low (non-stimulated) sTfR level corresponds to the quite frequent adaptation to iron deficiency and/or inhibition of resorption. Finally, extremely high sTfR levels were observed in some cases of malignancy such as in acute leukaemia and in hypernephroma. Thus, increased sTfR levels can be caused by paraneoplastic effects.

Reference values of lymphocyte subsets in the normal healthy adult Kuwaiti Arab population

Fluorescent monoclonal antibody labelling followed by a lysed whole blood method and flow cytometry was used to determine the lymphocyte subpopulations in 127 (64 males and 63 females) normal healthy individuals in the adult (age 18-59 years) Kuwaiti population. Relative percentages and absolute values of CD2+, CD3+, CD19+, CD4+, CD8+, HLADR+, CD56+, CD45RO+, and CD45RA+ cells were determined. The reference ranges were CD2+, 73-92% (0.95-2.99 x 10(9) per l), CD3+, 64-85% (0.83-2.71 x 10(9) per l), CD19+, 6-22% (0.05-0.61 x 10(9) per l), CD4+, 34-54% (0.45-1.65 x 10(9) per l), CD8+, 20-42% (0.29-1.17 x 10(9) per l), HLADR+, 4-23% (0.02-0.62 x 10(9) per l), CD56+, 4-22% (0.06-0.58 x 10(9) per l), CD45RO+, 16-53% (0.26-1.42 x 10(9) per l) and CD45RA+, 35-72% (0.34-2.05 x 10(9) per l). The mean CD4/CD8 ratio was 1.50+/-0.35. CD3+ cells were positively correlated to both CD4+ and CD8+ cells (P<0.001), and CD4+ cells showed a significant positive correlation with CD8+ cells (P<0.001).

Vaccine strategies in non-Hodgkin's lymphomas

As described above, the most recent advances in anti-idiotype vaccination strategies have gone hand in hand with recent developments in molecular biology and other forms of cancer therapy. The techniques that are currently available in antibody engineering will greatly facilitate protein production and purification and will reduce the time and effort needed to produce the patient specific vaccines. Cytokine (gene) therapy has extensively been studied in cancer treatment and cancer vaccination and some therapeutic strategies are currently being evaluated in clinical trials (Bubenik, 1996). Combination therapy of idiotypic vaccination with cytokine therapy has recently been explored with promising results. The main focus so far has been on GM-CSF and IL-2, although other cytokines might prove to be efficient in stimulating different effector arms of the immune system. The nature of the immune response mounted by the host against the tumour and the mechanisms by which the tumour cells escape the effector functions of the immune system are not yet fully known. A better knowledge of the nature of B-cell lymphomas and the relation to the patient's immune system will therefore benefit the further development of the therapeutic strategies. Further research will provide us with a better view of how to break the immune tolerance and of which components of the immune system have to be targeted in order to obtain optimal therapeutic results.

Autotumour reactive T-cell clones among tumour-infiltrating T lymphocytes in B-cell non-Hodgkin's lymphomas

Seventy-three T-cell clones (TCC) were established from tumour-infiltrating lymphocytes-T (TIL-T) derived from lymph nodes involved by B-cell non-Hodgkin's lymphomas (B-NHL) in nine patients with different histological subtypes and clinical stages. 40 TCC (55%) expressed the CD25 Ag and were also able to proliferate in the presence of irradiated autologous B-NHL cells. Among them, 23 autotumour (AuTu) proliferative TCC were found not to proliferate to autologous EBV-transformed B-cell lines, indicating that the proliferative reactivity of these TCC was preferentially directed at autologous B-NHL cells. Tested against autologous B-NHL cells, only three AuTu proliferative TCC (CD8+) showed a significant level of cytotoxicity (specific lysis > 15%). In blocking experiments, the AuTu proliferative reactivity of three TCC from one patient was strongly inhibited by anti-DR and anti-DQ mAbs, whereas that of three TCC from another patient was not affected by either anti-MHC class I or class II (DR, DP, DQ) mAbs. These findings suggest that the recognition of autologous B-NHL cells by AuTu proliferative TCC may occur through MHC-restricted as well as MHC-unrestricted mechanisms.

Immunophenotyping of normal lymphocytes

We report the data of direct and indirect immunofluorescence labelling of peripheral blood mononuclear cells obtained from 40 normal controls and nine patients having blood tests for non-haematological disorders (PNHD controls) using flow cytometric analysis. Polyclonal and monoclonal antibodies were used to define the expression of cell surface antigen of T cells, their subsets, B cells, natural killer cells (NK) and myeloid cells. Normal values of absolute number and percentages of each of the populations of mononuclear cells were established and were sufficiently reproducible to be of clinical use. The percentages of positive values of T cells, T-cell subsets, and B cells in ten normal controls when mononuclear cells were used, were comparable to those using whole blood lysis, APAAP immuno-alkaline phosphatase, and E and M rosettes. The results obtained were similar in both the normal and PNHD controls. In most instances the percentage recovery of identified T, B and NK cells was complete. Currently we are using the results as reference values for lymphoid sub-populations in normal controls.

CD7+ stem cell leukemia/lymphoma. Features of a subgroup without circulating blast cells

Recent advances in immunology have clarified the cellular origin of hematopoietic neoplasms. Blast cells with a CD7+ CD4- CD8- phenotype are demonstrated to originate from malignant pluripotent hematopoietic stem cells. In this article, the authors describe three rare cases, designated as a lymphoma type of CD7+ stem cell leukemia/lymphoma, with clinical features described below. All three patients were admitted with non-Hodgkin lymphoma with a 2-month to 4-month history of lymphadenopathy. Histologic examination of lymph nodes showed lymphoblastic lymphoma (LBL) in all patients. Bone marrow blast cells had an immunophenotype consistent with CD7+ CD4- CD8- acute leukemia, although abnormal cells were not observed in the peripheral blood during the course of the disease. One patient had a recurrence in the bone marrow, with myeloperoxidase-positive blast cells expressing myeloid differentiation antigens. Chromosomal analysis detected a common abnormal karyotype initially and at relapse. Furthermore, the same T-cell receptor gene rearrangement was found initially and at relapse, suggesting that these blast cells originated from the same pluripotent leukemic clone. Additional studies on more patients are required to determine the clinical significance of this group, including the difference from CD7+ stem cell leukemia/lymphoma with circulating blast cells (leukemic type) or LBL.

Ly-1 B (B-1) cells are the main source of B cell-derived interleukin 10

We have previously reported (O'Garra, A. et al., Int. Immunol. 1990, 2:821) that murine B lymphomas and purified normal peritoneal B cells produce interleukin (IL) 10. We now show that this production of IL 10 B cells correlates with the presence of Ly-1 (B-1) B cells, in both normal and diseased mice. Using a semi-quantitative modification of the polymerase chain reaction, we show that IL 10 expression is detectable in peritoneal B cells but only becomes apparent in splenic B cells of aged mice of which a high proportion are Ly-1+. Furthermore, the expression of IL 10 is constitutive in splenic B cells from mice carrying the Ly-1+ BCL1 lymphoma. Since IL 10 is a potent regulator of in vitro immune function, its production by Ly-1 lineage B (B-1) cells raises the possibility that this subset of B cells may regulate their own development and/or the function of other immunocompetent cells.

Detection, isolation and functional studies of CD25+ T cells in lymph nodes involved by B-cell non-Hodgkin's lymphomas

We searched for the presence of IL2 receptor (CD25) on T cells as an activation marker in lymph nodes involved by B-cell non-Hodgkin's lymphomas (B-NHL). In 26 malignant lymph nodes studied, the number of CD25+ T cells among total T cells was usually low when assessed by immunofluorescence analysis (mean +/- SD: 6.7% +/- 11.2%), but greatly increased when an immunomagnetic rosette method was used (mean +/- SD: 17.5% +/- 16.6%). In six cases, CD25-/CD25/CD25+ cells were isolated by immunomagnetic separation, with a purity greater than 97% for both populations. Expansion of CD25-/CD25+ T cells was obtained with IL2 and PHA, then conditioned media (CM) were prepared. No IL2 activity was found in CM from both CD25-/CD25+ T cells when tested on CTLL2 cells. BCGF and BCDF mu/gamma activities were assayed on normal B cells stimulated with soluble or insolubilized anti-mu antibodies(BCGF) or with Cowan I (BCDF). Results of production of all these activities were comparable for both populations, and thus do not favour the possibility that CD25+ T cells closely associated with malignant B-NHL cells in lymph nodes may influence their proliferation (BCGF) or expression/secretion of heavy chain isotype (BCDF mu/gamma).

Impaired clonogenic potential of CD25 positive T cells in lymph nodes involved by B cell non-Hodgkin's lymphomas

In vivo activated T cells (CD25+) present in lymph nodes involved by B-non-Hodgkin's lymphomas (B-NHL) were investigated here for their ability to proliferate in vitro. CD25-/CD25+ T cells were isolated using a rosette method with magnetic beads, then the frequency of proliferating T lymphocyte-precursors (PTL-P) in both populations was assessed by limiting dilution experiments, in the presence of IL2, PHA and allogeneic spleen cells as feeders. In a total of 16 cases studied, growing microcultures were observed in all cases for CD25- T cells (mean value of PTL-P frequency: 1/32; range 1/10 - 1/2899) but in 6 cases only for CD25+ T cells (mean value of PTL-P frequency: 1/441; range 1/119 - 1/3736); the absence of any proliferative cultures in the 10 other cases indicated that the number of PTL-P was inferior to 1/12480. These results suggest that the proliferative potential of CD25+ T cells infiltrating lymph nodes involved by B-NHL is paradoxically decreased.

Large B-cell lymphomas with a high content of reactive T cells

Twenty-one cases of large, B-cell lymphoma with an unusually high content of reactive T lymphocytes are described in this report. Fifteen patients presented with lymphoma in nodal sites and six patients presented with lymphoma in extranodal sites. With two exceptions, all patients were more than 50 years of age. The male to female ratio was 1:2. Histologically, isolated to small groups of large lymphoid cells were intermingled with many small lymphocytes. The large cells were neoplastic and exhibited B-lineage markers; immunoglobulin light chain restriction could be demonstrated in two thirds of the cases. There was a rich infiltrate of immunophenotypically mature T lymphocytes that comprised more than 50% of the cellular population. The T lymphocytes ranged from small cells with dark, round nuclei to slightly larger cells with elongated, irregular nuclei. There were occasional medium-sized blastic cells. There was also a variable infiltrate of histiocytes with or without epithelioid features, eosinophils and plasma cells, and increased vascularity. The peculiar morphologic features were also reproduced in other sites in the four patients for whom additional histologic materials were available for examination. We postulate that the abundance of T cells results either from a florid host reaction or from cytokine secretion by the neoplastic B cells, attracting T cells to the vicinity. The morphologic and immunologic features mimic those of a variety of benign lymphoproliferative diseases, angioimmunoblastic lymphadenopathy and lymphomas arising in angioimmunoblastic lymphadenopathy, peripheral T-cell lymphoma, secondary B-immunoblastic lymphoma, and Hodgkin's disease. Careful morphologic evaluation and immunophenotypic studies using leukocyte antibodies reactive in paraffin-embedded sections are of great assistance in determining a diagnosis.

Role of autologous lymph node T cells in membrane expression of mu- or gamma-heavy chain isotype by malignant B NHL cells

We investigated the possibility that T cells observed in lymph nodes involved by B-non-Hodgkin's lymphomas (B-NHL) may have a direct role in the expression of Mu- or Gamma- heavy chain isotype by autologous malignant B cells. T cells were separated from lymph nodes involved by B-NHL cells expressing either surface IgM (19 cases) or surface IgG (4 cases) and compared to peripheral blood T lymphocytes of healthy subjects (19 cases) for their ability to promote both IgG and IgM secretion in Cowan-activated normal B lymphocytes. The mean values of IgG/IgM ratios obtained under the influence of T cells associated with malignant B cells expressing either surface IgM or surface IgG were not statistically different to that obtained with the help of control T cells (0.60 and 0.62 versus 0.47, respectively). These results do not account for the hypothesis that autologous lymph node T cells may directly affect the expression of the heavy chain isotype by malignant B-NHL cells.

T cells in follicular centroblastic/centrocytic (cleaved follicular centre cell) lymphomas at diagnosis, relapse and transformation

Although T cells are often a prominent component of follicular (+/- diffuse) centroblastic/centrocytic (cleaved follicular centre cell--FCC) lymphomas (CB/cc/F +/- D), their evolution during the course of the disease and prognostic significance are uncertain. A total of 127 histopathologic and immunophenotypic studies from 77 patients with at least one histologic diagnosis of CB/cc/F +/- D were therefore retrospectively reviewed to address these questions. The proportion of T cells in each biopsy was analysed with reference to both histologic (diagnosis--Kiel and Lukes/Collins classification, presence of transformation, growth pattern, presence of residual mantle zones, biopsy sites) and clinical (biopsy date and number, treatment status) parameters. The actuarial survival for those patients whose first or second biopsy showed CB/cc/F +/- D and had immunophenotypic studies was also compared based on the proportions of T cells present. Among the biopsies which were obtained from 0 to 153 months following diagnosis, the mean proportion of T cells was 25 +/- 18 per cent. The only histopathologic group that showed a significantly different proportion of T cells were lymphomas of large cleaved FCC type (38 +/- 20 per cent). Although the number of T cells present varied greatly between different patients and among different biopsies in the same patients, neither biopsy number nor treatment status affected the mean proportion of T cells in CB/cc/F +/- D. With the exception of those biopsies from 1 to 11 months following diagnosis, the interval time between diagnosis and biopsy also did not affect the number of T cells present. Finally, the proportion of T cells in the lymphomas could not be shown to be of prognostic importance. Thus, the proportion of T cells in de novo CB/cc/F +/- D, at relapse or in transformation does not vary in a consistent fashion. Although extremely variable, the number of T cells present cannot be considered a feature of earlier or later disease and is not of demonstrable prognostic importance. Studies of specific subsets of T cells may provide more definite associations.

T cell malignancy in Richter's syndrome presenting as hyper IgM. Induction and characterization of a novel CD3+, CD4-, CD8+ T cell subset from phytohemagglutinin-stimulated patient's CD3+, CD4+, CD8+ leukemic T cells

A patient is described, having Richter's syndrome and immunodeficiency with hyper IgM, who developed suppressor T cell lymphoma (CD3+, CD4-, CD8+) following untreated helper-suppressor T cell chronic lymphocytic leukemia (CD3+, CD4+, CD8+). The neoplastic T cells in both malignancies expressed interleukin (IL) 2 receptors but were deficient in typical CD2+ and CD5+ pan T antigens. Additionally, a large percentage of malignant lymph node T cells expressed HLA-DR+ activation antigens. In vitro immunoglobulin-production experiments demonstrated that the patient's leukemic blood T cells had an excess helper function for IgM synthesis but a suppressor function for IgG and IgA synthesis by normal B and T cells. The leukemic blood T cells demonstrated a poor response to phytohemagglutinin (PHA). A defect in IL 2 receptor expression was evident in PHA-stimulated leukemic blood T cells. Of interest was the observation that PHA stimulated the induction of a novel CD3+, CD4-, CD8+ T cell subset from patient's CD3+, CD4+, CD8+ leukemic blood T cells. These PHA-induced CD3+, CD4-, CD8+ T cell subsets produced an elevated proliferative response to PHA and concanavalin A, had a helper cell function for IgM synthesis and produced highly elevated amounts of IL 2.

Correlation between histology and immunophenotype in a series of 322 cases of non-Hodgkin's lymphoma

The non-Hodgkin's lymphomas (NHL) are a heterogeneous group of lymphoid neoplasms displaying a wide variation in cell morphology, histological patterns, immunological phenotype and prognosis. In this paper we compare the results of phenotypic investigation of 322 tissue biopsies with the histology based on the Kiel classification. Immunological analysis revealed that 81 per cent of these tumours were of B cell origin, 12 per cent of T cell origin and the remaining 7 per cent could not be characterized as representing either cell lineage. This last group included a number of cases which had received a histological diagnosis of true histiocytic lymphoma. The original morphological diagnosis, based on routine haematoxylin and eosion sections correlated with the immunologically determined phenotype in 86 and 93 per cent of the T- and B-cell cases respectively. The B cell tumours were phenotypically heterogenous with respect to immunoglobulin (Ig) heavy chain and B lymphocyte subset marker expression. IgG was most often found associated with NHL of cb/cc histology and a small subgroup of lymphocytic NHL. IgA expression was uncommon and occurred in combination with IgD and G in three cases and alone in two cases of NHL. The most common immunoglobulin isotype expressed was IgM this isotype occurred with IgD most often in lymphocytic and centrocytic NHL and less often in tumours of cb/cc histology. Whilst greater than 90 per cent of the lymphocytic NHLs expressed the CD5 antigen, between 20 and 75 per cent of B-cell tumours of other histologies also expressed this epitope. The CD10 antigen and the epitope recognized by the monoclonal reagent FMC7 were widely distributed on tumour cells from all histologies. TdT expression commonly regarded as a marker for immature cells was found in one case of follicle centre cell lymphoma. All cases of T cell NHL displayed marked heterogeneity for both pan T and T subset antigens which is significant in terms of the routine diagnosis of T NHL and with regard to the rational classification of node based T NHL. Unlike resting peripheral blood T cells, MHC class II, OKT 10 and CD25 epitopes were expressed reflecting activation of tumour populations.(ABSTRACT TRUNCATED AT 400 WORDS)

Limiting dilution analysis of the frequency of IL2 responsive T cells in lymph nodes involved by B-cell non-Hodgkin's lymphomas

Total T lymphocytes separated from twelve lymph nodes involved by B-NHL were studied in limiting dilution experiments for their ability to proliferate in the presence of both R-IL2 used at a final concentration of 40 U/ml and irradiated autologous malignant B cells as feeders. The number of proliferating T-lymphocyte precursors (PTL-P) thus estimated was low in each case (mean: 1/4503; range, 1/200 to 1/11013). Once expanded, proliferation of the IL2 responsive T cells in the presence of autologous malignant B cells remained strictly dependent on the addition of exogenous IL2. Control cases consisted of T lymphocytes separated from peripheral blood of six healthy subjects and cultured in the presence of both R-IL2 (40 U/ml) and irradiated autologous total mononuclear cells as feeders; the mean frequency of PTL-P thus obtained (1/173; range, 1/49 to 1/457) was significantly higher than in malignant lymph nodes (p less than 0.01). These findings do not support the hypothesis that, in this series of patients, expansion of malignant B cells may lead to the activation and growth of T cells sensitized against the tumour.

Lymphocyte immunophenotyping of B-cell lymphomas: a flow cytometric analysis of neoplastic and nonneoplastic cells in 271 cases

We have reviewed our experience with 271 B-cell lymphomas to determine the effectiveness of flow cytometry in the characterization of these malignancies. Flow cytometric immunophenotyping of the total lymphocyte and/or large lymphocyte populations confirmed the morphologic diagnosis of B-cell lymphoma in 92% of cases, which included 79% monoclonal and 13% surface immunoglobulin (SIg)-negative lymphomas. Light chain monoclonality was most frequent in low grade and follicular center cell (FCC) lymphomas, while SIg-negative cases were most common in high grade and non-FCC types. Low grade lymphomas of all histologic types had high median percentages of neoplastic cells and low T-cell percentages. Conversely, high grade lymphomas exhibited lower and less uniform median percentages of B-cells, with higher numbers of T-cells and lower CD4/CD8 ratios than low grade lymphomas. Several differences in B- and T-cells were observed between specific high grade histologic types. FCC lymphomas with a diffuse pattern had lower percentages of CD4+ cells and lower CD4/CD8 ratios than cases with a follicular pattern. Thus, immunophenotypic differences were observed between histologic types or groups with known differences in clinical course and prognosis. We conclude that flow cytometry provides reliable information on neoplastic and nonneoplastic cells in lymph nodes involved by B-cell lymphomas.

Analysis of a murine B cell lymphoma, CH44, with an associated non-neoplastic T cell population. I. Proliferation of normal T lymphocytes is induced by a secreted product of the malignant B cells

A non-neoplastic T cell population associated with a murine monoclonal B cell malignancy, CH44, was analyzed. Immunofluorescence on cell suspensions and immunoperoxidase staining on tissue sections using monoclonal antibodies to the antigens Thy1.2, Ly-1, L3T4, and Lyt-2 confirmed the presence of both TH (Ly-1/L3T4+, Lyt-2-) and Tc/s (Ly-1/L3T4-, Lyt-2+) T cell subpopulations. The non-neoplastic T cells were present in both a 0.6 and 2.1 g CH44-bearing spleen. T cells, not normally in liver in significant numbers, were found in liver tissue when the CH44 tumor cells were present. These data implied an active proliferation of the T cell populations within tissues containing the malignant B cells. Supernatant from an in-vitro-adapted cell line of CH44 (CH44.LX) was tested for its ability to induce proliferation of normal murine splenocytes and thymocytes. As assayed by tritiated thymidine incorporation, both spleen and thymus cells proliferated in the presence of CH44.LX supernatant. Although supernatant from two of nine other B cell lines was able to stimulate the proliferation of spleen cells, only CH44.LX could induce proliferation of thymus cells. Supernatant from the seven other B cell lines and three hybridomas had no measurable effect on either splenocytes or thymocytes in this assay. It is hypothesized that the presence of a non-neoplastic proliferating T cell population associated with a neoplastic B cell lymphoma during in vivo passaging of the tumor is the result of effects derived from a secreted product of the malignant B cells. Whether the T cells have any effect on the growth of the malignant B cells is not known.

The value of immunocytochemical staining of lymph node aspirates in diagnostic cytology

This study investigates the applicability of immunocytochemical techniques towards improving the cytological diagnosis of lymph node disorders. Cytocentrifuge preparations of fine needle aspirates were examined using an indirect immunoperoxidase method and the alkaline phosphatase-antialkaline phosphatase method. 36 reactive lymph nodes were evaluated. 23 patients showed T cell predominance as assessed by the presence of CD3+ cells. 13 patients showed an excess of CD24+ cells over CD3+ cells. In all patients the B cell population showed no light chain class restriction. 48 aspirates from patients with B-non-Hodgkin's lymphoma of low malignancy were investigated. The majority of the cells in each of these cases expressed CD24 and 47 cases were monoclonal with respect to their light chain determinants. In 37/48 cases the antibody OKT9 reacted with less than 15% of cells. 18 aspirates were obtained from patients with B-non-Hodgkin's lymphoma of high malignancy. 17 patients showed light chain class restriction and a high percentage of CD24+ (greater than 80%) and OKT9+ (greater than 40%) cells. 8 malignancies were considered to be of T-cell origin. A low percentage (less than 15%) of Ig+CD24+ cells with a high number of CD3+ and/or CD4+ cells suggests a T-cell lymphoma. The majority of neoplastic cells in peripheral T-cell lymphomas (excluding mycosis fungoides) expressed OKT9 and CD3 expression was found to be variable. In 15 cases of Hodgkin's disease, there were 11 correct cytologic diagnoses. A significant number of BerH2 (CD30)+ cells having the morphology of Sternberg-Reed cells supports this diagnosis. 25 aspirates were obtained from patients with metastatic malignant tumours. Marker studies in eight cases helped in distinguishing metastatic malignant tumours from malignant lymphomas. Our findings indicate that the immunocytochemical technique is applicable to cytological material and that the simplicity of the procedure merits application to routine diagnostic cytology.

Activation and differentiation antigen expression in B-cell non-Hodgkin's lymphoma

In an attempt to establish whether extended immuno-phenotyping allows more accurate definition of subgroups of B-cell non-Hodgkin's lymphoma (NHL) we have stained a series of 145 cases with a large panel of monoclonal antibodies that recognize B-cell differentiation and activation antigens. No antigen was expressed by all cases. The B-cell histogenesis in many cases could be confirmed only by using a panel of immunoglobulin and pan B-cell markers. There was marked phenotypic heterogeneity within and between major groups of B-cell NHL as delineated by the Kiel classification although the differentiation antigens CD5 (lymphocytic and centrocytic NHL) and OKT10 (plasma cell tumours) were more often expressed by certain morphological groups. The activation antigens 4F2 and transferrin receptor were expressed more strongly and more often by high grade NHL but other activation antigens (CD23 and CD25) were not more frequently associated with these tumours. Extended phenotyping may be of value in improving the understanding of biological abnormalities and processes involved in B-cell NHL, but we conclude that a limited panel of markers (CD3, CD5, CD22, CD45, IgM, kappa, and lambda) should be sufficient for routine diagnosis and classification of most cases.

Killing of K562 cells with conjugates between human transferrin and a ribosome-inactivating protein (SO-6)

Cellular iron uptake is mediated by binding of transferrin with specific surface receptors and internalization of the Fe-transferrin-receptor complex. This has been examined as a possible pathway for carrying into leukaemic cells a ribosome-inactivating protein (RIP), SO-6, derived from Saponaria officinalis. Purified human differic transferrin was conjugated with SO-6 and a pool of proteins was obtained, with variable numbers of SO-6 molecules linked to a single transferrin molecule. Human erythroleukaemic K562 cells were grown in the presence of human transferrin, SO-6 and human transferrin conjugated with SO-6. The conjugate was found to be internalized via binding with transferrin receptor. Whereas the presence of unconjugated human transferrin and SO-6 in the medium did not significantly influence K562 cell growth, the conjugated proteins displayed an inhibitory activity on cell proliferation. This was maximal after 72 h at a transferrin concentration of 10(-9) M, with about 50% of cells being killed. Bovine transferrin, present in fetal calf serum, did not appear to compete with human diferric transferrin in binding to K562 cells in suspension culture. In a clonogenic assay, colony formation by leukaemic cells was not influenced by free SO-6 or transferrin, whereas the conjugated proteins were markedly inhibitory (about 100% at 10(-9) M). Our findings indicate that SO-6 can be efficiently carried into mammalian cells via the transferrin-transferrin receptor cycle and exert its ribosome inactivating activity. This is in keeping with the existence of an alternative pathway of transferrin endocytosis in addition to the classic acidic endosome pathway. From a practical viewpoint, conjugates between transferrin and SO-6 can be useful tools for studying the expression of transferrin receptors, and deserve also to be investigated for a possible use in cancer therapy.

Flow cytometric detection of B-clonal excess in fine needle aspirates for enhanced diagnostic accuracy in non-Hodgkin's lymphoma in adults

Fine needle aspiration (FNA) cytology is a valuable aid to diagnosis and tumour staging in patients with non-Hodgkin's lymphoma. These tumours are often multicentric and involve sites such as the liver or the spleen which are not easily accessible to surgical biopsy. Particularly with splenic involvement, there is a diagnostic problem of morphologically distinguishing the lymphoma cells in an admixture of normal lymphocytes. Since most lymphomas in adults are of B-cell origin, we studied the diagnostic value of adding a surface immunoglobulin (sIg) light chain analysis to the cytological evaluation of FNAs. B-clonal excess was determined by flow cytometric analysis of the sIg light chain distribution and a monoclonal finding was considered diagnostic of lymphoma. In primary diagnostic procedures the light chain analysis established a diagnosis of lymphoma in 5/14 (36%) aspirates from patients with poorly differentiated tumours. Fine needle aspirates performed as part of staging procedures were morphologically normal or inconclusive in 19 cases; in seven of these (37%) lymphoma involvement was diagnosed by the light chain analysis. Diagnostic precision was enhanced by combining morphological and immunological evaluation of fine needles aspirates in patients with established or suspected non-Hodgkin's lymphoma.

Differentiation-linked leukemogenesis in lymphocytes

Most human lymphoid malignancies preserve a pattern of gene expression reflecting their proliferative activity and the development level of clonal expansion and maturation arrest. Characteristics of leukemia and other cancer cells frequently considered to reflect aberrant differentiation may more often reflect clonal selection of cell types that are normally infrequent and transitory. The differentiation status of progenitor or mature lymphoid cells influences which genetic elements are at risk of being exploited, via mutation, recombination, or deletion, for clonal advantage. These alterations may frequently arise spontaneously as a consequence of the unique developmental and functional programs of lymphoid cells and have as a major phenotypic consequence the stabilization of transitory cellular phenotypes.

The demonstration of B-cell, T-cell and myeloid antigens in paraffin sections

The monoclonal antibodies MB1 and MT1, which detect B cells and T cells respectively, have been applied to human lymphoid tissues. The distribution of staining within paraffin sections was compared with that observed using frozen sections and was found to be identical. The antibodies were then applied to paraffin sections of 19 B-cell lymphomas and 10 T-cell lesions in which full immunophenotyping had been performed. The B lymphomas all consisted of a large majority of MB1 positive cells with a variable infiltrate of small MT1 positive lymphocytes. The T cell lesions consisted of MT1 positive cells with few MB1 positive cells except in residual B cell areas of lymph nodes. In paraffin sections from cases of Hodgkin's disease anti-Leu M1 identified Reed-Sternberg cells and their variants and MB1 and MT1 showed a similar distribution of B cells and T cells to that demonstrated in previous studies using frozen sections. The results show that MB1 and MT1 are useful markers for B and T cells in routinely fixed paraffin embedded tissue. In conjunction with anti-Leu M1 they provide a valuable panel of antisera for the examination of lymph nodes and other biopsies when frozen tissue is not available.

Immunophenotypic analysis of non-Hodgkin's lymphomas in Chinese. A study of 75 cases in Hong Kong

The cell surface markers of 75 cases of non-Hodgkin's lymphoma were studied on cryostat sections using a panel of monoclonal antibodies. Forty-nine cases (65.3%) were found to express a B-cell phenotype, 23 cases (30.7%) a T-cell phenotype, 1 case (1.3%) a histiocytic phenotype and 2 cases (2.7%) no demonstrable surface markers. Follicular lymphoma accounted for only 10.7% of the cases. Most B-cell lymphomas expressed IgM-lambda or IgM-IgD-lambda, but a few failed to express surface immunoglobulin. Among the 23 cases of T-cell lymphoma, 22 were of peripheral T-cell type; most were of helper-cell (T4) phenotype and a significant number expressed J5 (CALLA) and I2 (HLA-DR). The present study shows that the percentage of T-cell lymphoma in Chinese is higher than in Caucasians, but lower than in Japanese. However, when the age-adjusted incidence of non-Hodgkin's lymphoma is considered, the incidence rates of T-cell lymphoma in Hong Kong Chinese and Japanese in areas non-endemic for adult T-cell lymphoma/leukemia are similar; the incidence in Americans is similar or slightly lower. The major difference between the races is that B-cell lymphoma, particularly the follicular type, is much rarer in Asians than Americans.

An immunohistochemical study of non-Hodgkin's lymphomas: correlation of morphological appearances and immunophenotype in 148 cases

An unselected series of 148 cases of non-Hodgkin's lymphoma has been studied by immunohistological methods. In each case, the morphological features displayed in paraffin sections were correlated with the immunophenotype, determined using a panel of monoclonal antibodies. Of the lymphomas 82% were B-cell type, 28% of follicle centre cell origin, 17% lymphocytic or immunocytic and 30% of large cell type. All the B-cell tumours expressed pan-B antigen, and nearly all HLA-DR. In most, light chain monoclonality was demonstrable. Nearly all had moderate to large numbers of T-cells of both subtypes interspersed amongst the B-lymphocytes. Follicle centre cell tumours expressed surface IgM and IgD and had numerous dendritic reticulum cells. Lymphocytic and immunocytic lymphoma expressed IgM but less IgD, and had fewer or no dendritic reticulum cells. Large cell lymphoma expressed either no immunoglobulin or only IgM, and contained ragged dendritic reticulum cells, giving the appearance of 'burnt-out' follicles. T-cell lymphomas usually showed a clear preponderance of either helper or suppressor subtype. Additionally, they contained residual B-cells and sometimes germinal centres. Only 3% of this series were 'non-B, non-T', and only one case HLA-DR negative, so the 'null' or 'unclassifiable' group is very small when information from antibody markers is available.

Isolation and characterization of Leu 7+ germinal-center cells with the T helper-cell phenotype and granular lymphocyte morphology

Leu 7+ cells in germinal centers of lymphoid tissues largely (greater than 90%) coexpress the T helper-cell marker, Leu 3. In this study we have isolated Leu 7+ (Leu 3+) cells from pharyngeal and palatine tonsils and we have analyzed their surface phenotype, morphologic and cytochemical characteristics, and functional properties. All of these features have been compared with those of T helper-cell populations with natural killer (NK)-like characteristics that we have previously described in peripheral blood. Leu 7+ (Leu 3+) cells from tonsil germinal centers display morphological and cytochemical features of granular lymphocytes and express the T3 marker in the absence of Leu 15. Following stimulation with phytohemagglutinin (PHA) or anti-T3, Leu 7+ (Leu 3+) cells express interleukin-2 (IL-2) receptors and proliferate to some extent in response to IL-2. The localization of Leu 7+ (Leu 3+) cells in B-dependent areas of lymphoid tissues suggests that they may play a regulatory role in B-cell proliferation and/or differentiation. Here we show that Leu 7+ (Leu 3+) cells do not produce B-cell growth factor (BCGF) and do not help pokeweed mitogen (PWM)-driven B-cell differentiation. Therefore, Leu 7+ (Leu 3+) germinal-center cells are distinct from "classic" T-helper cells of blood and lymphoid tissues.

Growth fraction of tumour cells and infiltration density with natural killer-like (HNK1+) cells in non-Hodgkin lymphomas

Two markers for cells in the growth fraction, the T9 antigen (i.e. the transferrin receptor) and the T10 antigen were investigated in frozen tissue sections of 105 non-Hodgkin lymphomas (NHL). The results were correlated with the histological subtype and the pattern of tumour infiltration by reactive cells. Special attention was directed to the density of natural killer (NK)-like cells using the anti-HNK1 (Leu7) antibody since the transferrin receptor (tfr) or other growth-associated membrane structures may serve as target for NK cells. Our study confirms a relationship between number of tumour cells with the T9 marker and tissue infiltration by HNK1+ cells in NHL of low (chronic lymphocytic leukaemia, hairy-cell leukaemia, immunocytic lymphoma, centroblastic-centrocytic lymphoma) and intermediate (centrocytic and centroblastic lymphoma) but not in NHL of high malignant grade (immunoblastic and lymphoblastic lymphoma). Comparable results were obtained with the T10 antigen although the correlation was less close. The percentage of cells in the growth fraction, defined by the expression of the T9 and T10 marker, corresponded with prognostically unfavourable subgroups with the remarkable exception of follicular NHL of centroblastic-centrocytic type. This lymphoma showed high numbers of cells with the T9 and the T10 marker in a microenvironment resembling normal germinal centres in many aspects.

Lymphocyte populations and TAC-antigen in diffuse B-cell lymphomas

Immune cell populations in 8 diffuse histology B-cell lymphomas were analysed in frozen tissue sections by indirect immunofluorescence to gain insight into their possible modulating influence in these tumors. Use of monoclonal antibodies to identify cellular and extracellular antigens combined with nuclear counterstaining allowed precise quantitation, localization and comparison of T- and B-lymphocyte populations. T lymphocytes clustered in non-random fashion. Areas of high T-lymphocyte density manifested higher T4:T8 ratios than locales with fewer T lymphocytes (p less than 0.05). Few cells had surface antigens (Leu 7, 73.1, OKM1) associated with natural killing. Cells strongly reactive with anti-TAC (Interleukin-2 receptor, associated with T-lymphocyte activation) were also T11 reactive and were usually helper (Leu 3) phenotype. In addition, B-lineage lymphoma cells in some tissues reacted with anti-TAC. The pattern of tumor cell reactivity with anti-TAC correlated with Rappaport histologic classification. These findings suggest that non-malignant T lymphocytes modulate B-lymphoma cell growth in situ, and that in some lymphomas the T-cell product IL-2 may be an important local growth factor.

Flow cytometric light chain analysis of peripheral blood lymphocytes in patients with non-Hodgkin's lymphoma

Peripheral blood lymphocytes from 96 patients with non-Hodgkin's lymphoma were studied, either at primary staging, during treatment or in follow up. The amount of surface immunoglobulin light chain per cell was determined by direct immunofluorescence staining analysed by flow cytometry. Discrepancy between kappa and lambda fluorescence profiles in the sample was considered to indicate the presence of monoclonal cells i.e., circulating lymphoma cells. The results were correlated with routine haematological findings, histopathology of the lymphoma and tumour burden. Using routine haematological methods leukaemic spread was evident in 24% of the patients in our study. Using kappa/lambda distribution analysis evidence of circulating lymphoma cells was found in an additional 27%. As expected, the major diagnostic gain was in the low grade malignant group, where 30% of the patients with normal peripheral blood according to standard procedures showed evidence of circulating lymphoma cells in the kappa/lambda distribution analysis. The corresponding gain in the high grade malignant group was 19%. In patients with active disease but without morphological evidence of leukaemia, 37% showed abnormal kappa/lambda distributions. In patients in complete remission the corresponding figure was 18%. The clinical significance of small numbers of circulating lymphoma cells is not yet understood, but a possible outlook is to use kappa/lambda distribution analysis to increase staging precision and in the early detection of relapse.

B- and T-cell subsets in follicular centroblastic/centrocytic (cleaved follicular center cell) lymphoma: an immunohistologic analysis of 26 lymph nodes and three spleens

Follicular centroblastic/centrocytic (CB/cc/F), or cleaved follicular center cell, lymphomas are known to contain admixtures of B cells and, often, numerous T cells. To analyze the presence and distribution of B and T cells and their subsets in CB/cc/F lymphomas, 26 lymph nodes and three spleens (from 24 patients) were studied with a panel of monoclonal antibodies and peanut lectin by the avidin-biotin immunoperoxidase technique on frozen sections. Immunoglobulin studies revealed monoclonal neoplastic follicles in most cases, although cells of the nondominant light chain were occasionally present. Rarely, the follicles showed both kappa and lambda light chains or were immunoglobulin-negative. Although monoclonal mantles were observed in only one case, more than half of the nodes demonstrated monoclonal interfollicular infiltrates. In most cases the phenotype of the follicular cells was similar to that of the predominant cells in the normal follicles. Interfollicular lymphomatous cells had variable phenotypes that, unlike the normal situation, sometimes resembled those in the follicles. Phenotypic variation was present within single neoplastic clones and sometimes suggested more mantle-like differentiation. Phenotypic changes were also observed in repeat biopsies. T cells, usually predominantly of the T-helper phenotype, were present in variable numbers in all cases. Although present in the neoplastic follicles, they were usually more common in the interfollicular areas. Six nodes and two spleens had definite rims composed predominantly of T cells around neoplastic follicles. Apparently "activated" (Tac-positive) T cells were often present and showed accentuation around the follicles in some cases. Thus, CB/cc/F lymphoma is a malignant lymphoma that closely resembles follicular hyperplasia but that also has distinctive features.

Infiltration density of HNK 1 positive cells in non-Hodgkin's lymphomas depends on histologic subtype: an in situ morphometric analysis

Numbers and distribution of HNK-1 (Leu 7) positive cells within 115 malignant Non-Hodgkin's lymphomas (NHL) were evaluated in situ by immunomorphometry. Results on the infiltration were related to histological and clinical parameters. A mean of 4.099 +/- 350 HNK 1+ cells/microliter tumor tissue was found, which was comparable to normal (reactive) lymphatic tissues (4.441 +/- 1.235) and was about a quarter of the population density of T helper/inducer (TH) and T cytotoxic/suppressor (TS) lymphocytes together. The distribution of HNK 1+ cells within the tumors was diffuse except in nodular lymphomas of follicular center cell origin (centroblastic/centrocytic = cb/cc NHL). When evaluating the different histological subgroups, the highest number of HNK 1+ cells was found within the tumor areas of cb/cc, which contained about three times as many positive cells as the other NHL. High numbers were also found in the diffuse variant of cb/cc but not in centrocytic NHL. Different degrees of HNK 1+ cell densities were observed in lymphocytic lymphomas (4.426 +/- 754), with high numbers in about 30% of the patients. Splenic tissues of 6 hairy cell leukemias displayed lower numbers of HNK 1+ cells as compared with other low grade malignant NHL. In "large cell" NHL, the lymphoblastic subtype showed only sparse HNK 1+ cells (1.345 +/- 386). The number was significantly reduced in comparison to all other NHL (p less than 0.01) and markedly lower than in the other NHL of high malignancy (immunoblastic and centroblastic NHL, p less than 0.02). The diminuation was not due to a simple dilution phenomenon in a rapidly proliferating tumor, as TH and TS infiltrates were comparable to other NHL. Correlating results with the clinical course (available in 58 patients), significantly higher numbers of HNK 1+ cells were found in NHL of low malignancy (p less than 0.02), but patients with a favourable course did not differ from those with progressive disease (p less than 0.5). Patients treated by cytotoxic drugs showed higher numbers of HNK 1+ cells than those before or without treatment (p less than 0.02). Results on TH and TS cell numbers in comparison to HNK 1+ cells showed completely different patterns of infiltration.

Gastrointestinal lymphoma

The gastrointestinal tract is the commonest site for primary extranodal malignant lymphoma. Despite this, gastrointestinal lymphomas are rare and present diagnostic and conceptual challenges. Principal among these are the differential diagnoses of malignant lymphoma and carcinoma and malignant lymphoma and pseudolymphoma, especially in the stomach; the nature of Mediterranean lymphoma and of the lymphoma complicating celiac disease; and the conceptual basis for differentiation of follicular centre cell lymphomas in the intestine.

Two monoclonal antibodies raised against a Burkitt lymphoma cell line recognise different cell types within lymphoid follicles

Monoclonal antibodies were raised against a laboratory derived variant of the Raji Burkitt lymphoma cell line. We have characterized two of these antibodies by screening on haematopoietic cell lines, and frozen sections of both reactive and neoplastic lymphoid tissue, and found reactivity with separate cellular components of lymphoid follicles. Monoclonal FW37.4.D5 reacts in section specifically with follicular dendritic reticular cells. Monoclonal 35.1C5 reacts with a subpopulation of splenic marginal zone, and lymph node mantle zone, B lymphocytes, but stains only rare cells within germinal centres. This monoclonal is operationally B lymphocyte specific, distinguishing an 'intermediate' B cell subset, represented in lymphoma by B chronic lymphocytic leukaemia, B hairy cell leukaemia and centrocytic lymphoma.

Immunohistochemical analysis of human MHC class II antigens in B-cell non-Hodgkin's lymphomas

Twenty cases of B-cell non-Hodgkin's lymphoma (NHL) were evaluated by immunohistochemical staining of frozen sections with a panel of anti MHC class II monoclonal antibodies (MCA). These studies showed marked differences in the expression of class II antigens both between different cases and within the population of cells of individual cases. In all of the cases studied the majority of the tumour cells reacted with MCAs directed against determinants common to the products of SB and DR loci. However, MCAs specific for DC determinants failed to react with 3/20 cases and in several other cases stained only a minority of cells. Absent or reduced expression of DC antigens was most marked in lymphocytic lymphoma; however, in centroblastic-centrocytic and centroblastic lymphomas, DC antigens could be detected on the majority of cells.

Normal values for the different classes of venous blood mononuclear cells defined by monoclonal antibodies

We present the data obtained from routine quantitation of normal venous blood mononuclear cells using 19 monoclonal antibodies against defined mononuclear cell surface antigens. The results indicate different values for percentage and absolute numbers of T lymphocytes and of T lymphocyte subsets depending on the monoclonal antibodies used to quantify these populations. In most instances the total number of identified cells was significantly less than the total number of recovered blood mononuclear cells, which suggests the existence in blood of a null cell population. Evidence is advanced to support previous observations that at least a proportion of this population is of B cell lineage, expressing cytoplasmic immunoglobulin but lacking other class or lineage specific markers. The value of a diverse monoclonal panel in routine quantitation of peripheral blood mononuclear cells is discussed.

T lymphoblastic lymphoma with LEU-7 positive phenotype and unusual clinical course: a multiparameter study

Immunologic phenotype studies were performed on cells and on frozen sections of involved tissue from a 20 year old female with typical T-cell lymphoblastic (convoluted) lymphoma. The cells demonstrated a thymic phenotype but in addition marked with Leu-7 (HNK-1)--an antibody reported to identify human natural killer/killer (NK/K) cells. Normal or neoplastic cells with this phenotype have not been previously reported. These findings support the existence of a thymic precursor for a T-cell subset of Leu-7 + cells. The unusual clinical response to therapy is another feature of this unique case.

Immunoglobulin negative follicle centre cell lymphoma

Immunoglobulin (Ig) could not be detected on the surface or in the cytoplasm of neoplastic cells from five cases of follicle centre cell lymphoma with centroblastic/centrocytic follicular histology when examined by immunohistology of frozen or wax embedded sections. Examination by fluorescein labelled antibodies of cells in suspensions prepared from the biopsies revealed a monotypic surface Ig positive population in one case and a surface or cytoplasmic Ig kappa:lambda light chain imbalance in a further two cases consistent with neoplastic B cell involvement: in all cases the proportion of cells failing to express Ig or T cell markers ranged from 24 to 75%. The monoclonal antibodies B1 (Pan B cell), FMC4 (HLA class II) and J5 (cALL antigen) stained the majority of cells in suspension with residual cells staining with UCHT1 or OKT11 (T cell monoclonal antibodies). In frozen sections, neoplastic follicular cells did not stain with UCHT1. However, in the one case tested these cells stained with the antibodies B1 and FMC4. In paraffin sections J chain could be demonstrated in the cytoplasm of three out of five cases. Cells from four cases were cultured in vitro for Ig production: two failed to produce Ig and monotypic light chains were the sole Ig product of the remaining two cases. The failure to express Ig by the majority of the neoplastic cells from the cases described in this report is at variance with the follicular histology of these neoplasms. Mechanisms responsible for this failure are discussed with reference to current models of B cell differentiation.

Reactivity of Leu 1 and T101 monoclonal antibodies with B cell lymphomas (correlations with other immunological markers)

The reactivity of Leu 1/T101 monoclonal antibodies (MoAb) was studied in a series of 69 lymphomas with B cell differentiation and was correlated with other cell markers. A three step immunoperoxidase technique on frozen sections was used to test a panel of 20 MoAb: anti-human Ig (heavy and light chains), To 15 (Pan B cells), Leu 1, T101, Leu 4, Leu 3a, Leu 5, OKT 8, OKT 6, Leu 7, anti-CALLA (IOT 5), Leu 10, anti-HLA-DR, OKM 1 and anti-dendritic reticulum cells (R 4/23). T101/Leu 1 antigen was detected in 24 cases: CLL (11 of 11), diffuse centrocytic lymphomas (four of 11), follicular lymphomas (none of 12), follicular and diffuse lymphomas (seven of 10) and one unclassified low grade lymphoma. This antigen was observed in only one high grade malignant lymphoma. In follicular lymphomas, two results deserve attention: (1) T101+ lymphomas showed most frequently IgM+, IgD+ surface Ig. Inversely, T101 unreactive lymphomas displayed IgM+, IgD+ phenotype. (2) Tp67 antigen (T101, Leu 1) and CALLA (GP 100) were found to be mutually exclusive in these lymphomas. These results suggest that follicular lymphomas could be derived from two distinct germinal center cell populations: IgM+ Ig'D-, Calla+, Leu 1-/T101- and IgM+, IgD+, CALLA-, Leu+/T101+.

Lymphocytic lymphoma/B-chronic lymphocytic leukaemia--an immunohistopathological study of peripheral B lymphocyte neoplasia

Twenty seven patients with malignant lymphoma of lymphocytic type/B-chronic lymphocytic leukaemia (ML, L/B-CLL, Kiel classification) diagnosed from lymph node and splenectomy specimens were studied histologically and immunologically. Lymph node biopsies showed a diffuse effacement of normal architecture by small round lymphocytes usually with scattered proliferation centres (PC). A1 spleens showed white pulp with or without red pulp involvement, sometimes with tumour nodules present. PC-like cells or PC were only found in the white pulp or tumour nodules. Studies of 13 specimens using the ABC immunoperoxidase technique on frozen sections with a large panel of monoclonal antibodies showed that although a part of the monoclonal B cell neoplasm, the proliferation centres or splenic white pulp have a different phenotype from the surrounding cells. Some of these phenotypic changes are similar to those reported with in vitro induction of "maturation" of ML, L/B-CLL cells. The implications for normal B-cell development are discussed. In contrast to reported peripheral blood findings, T cells, predominantly of T helper phenotype in lymph nodes, were present but usually not numerous.

Primary B-cell malignant lymphoma of the maxilla with a sarcomatous pattern and multilobated nuclei

Three cases of primary malignant lymphoma of the maxilla are reported. The primary intraosseous origin of these tumors was demonstrated by x-ray examination and surgical exploration. The initial interpretation as odontogenic infection led to a delay in starting therapy of 9 months in one case. Biopsies of two cases were initially interpreted as sarcoma because of a dense reactive fibrosis between the tumor cells. Subsequently, hemimaxillectomy was performed in one case. Histologically and ultrastructurally the tumor cells showed marked nuclear abnormalities with cleavage, folding, and lobulation. Immunohistochemical studies of two cases showed a monoclonal immunoglobulin expression, IgG-K; T-lymphocyte-associated antigens were not detected on the tumor cells. The findings indicate the existence of a primary B-cell malignant lymphoma of bone with multilobated nuclei. The lymphoid nature may be masked by a dense proliferation of connective tissue. The relation of these tumors to the classifications for malignant lymphoma of lymph node is discussed.

Caribbean T-cell lymphoma/leukemia

Caribbean T-cell lymphoma/leukemia (CATL) is a recently described neoplasm similar to Japanese adult T-cell leukemia/lymphoma, but it occurs in patients born in a different geographic region. Four adult Black West Indian women with CATL were studied using a multiparameter approach, including clinical, hematologic, pathologic, and immunologic investigations. The disease was usually characterized by adenopathy (with or without hepatosplenomegaly), peripheral blood involvement, hypercalcemia often in the absence of gross bony lesions, and a poor prognosis. The neoplastic cells were pleomorphic with marked nuclear irregularity of a multilobated or more cerebriform type. Lymph node biopsies demonstrated a diffuse pleomorphic lymphoma with variable degrees of nuclear irregularity and transformation. Marrow involvement consisted of focal nodules or, more commonly, scattered atypical lymphoid cells. Marrow biopsies also often demonstrated osteoclastic activity. Cases were all of T-cell origin, most commonly of T-helper phenotype, although there was some phenotypic heterogeneity. All patients had antibodies to the human T-lymphoma/leukemia virus.

Imbalance of helper and suppressor T lymphocytes in malignant non-Hodgkin lymphomas: an in situ morphometric analysis

The number and distribution of reactive T cells within 100 malignant B-cell lymphomas were evaluated in situ by immunomorphometry using stereological methods. Findings were related to histological and clinical parameters. A mean of 2 X 10(4) reactive T cells/microliter tumour tissue was found. This corresponds to 40% of the T-cell content of normal lymphatic tissues. The distribution of reactive T cells within the tumours was diffuse except for centroblastic/centrocytic lymphomas. When evaluating the different histological entities a correlation between number of helper T cells, T helper:T suppressor (TH:TS) ratio and histological subgroups emerged, particularly in non-Hodgkin lymphomas of low-grade malignancy. The highest ratio was found in prognostically favourable subgroups, CLL (2.7 +/- 0.3) and tumour areas of centroblastic/centrocytic lymphomas (2.9 +/- 0.4). In contrast, a significantly lower ratio was found in centrocytic lymphomas (1.4 +/- 0.3) corresponding well to the worst prognosis of this subgroup. The relationship between the number of helper T cells in tumour tissues, TH:TS ratio and prognosis was confirmed and extended by the evaluation of clinical data. It could be shown that, independently of histological criteria, a close correlation exists between the number of T cells, particularly T helper cells within the tumour, TH:TS ratio and clinical course. Patients with a favourable course had 1.4 X 10(4) T helper cells/microliter tumour tissue compared to only 0.8 X 10(4) for patients with an unfavourable clinical course (p less than 0.01); the TH:TS ratio was 2.8 for the favourable and 1.8 for the unfavourable group, respectively (p less than 0.04). In contrast, neither treatment nor tumour stage had a clear-cut influence on the extent of T-cell infiltration.

Human T-cell leukemia virus (HTLV) in the United Kingdom

Ten out of 26 leukaemic patients who had emigrated from the Caribbean region to the United Kingdom had adult T-cell leukaemia with associated serum antibodies to HTLV I. Antibodies to HTLV were also detected in sera from a small proportion of non-leukaemic Caribbean immigrants but not in any sera from other (non-ATL) T-cell leukaemias or a variety of control groups. The long period between immigration to the UK and diagnosis of leukaemia (up to 30 years) suggests that an extensive latent period in disease development may exist. Cell lines were isolated from two patients with HTLV antibody-positive ATL and were shown to be virus-positive by electron microscopy and immunofluorescence using antibodies to the p19 and p24 viral proteins. HTLV1 provirus integration and active transcription were demonstrated by Southern blotting of DNA and in situ hybridization respectively using molecularly cloned HTLV1 probes. Virus from one of these cell lines could be transmitted to normal T cells by co-cultivation.