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FCRL (also known as FREB and FcRX) is a recently described member of the family of Fc receptors for immunoglobulin G (IgG). In the present study we analysed its expression in normal and neoplastic lymphoid tissue using immunohistochemical techniques. FCRL was preferentially expressed in a proportion of germinal centre cells and, more weakly, in mantle zone B cells. In addition, strong labelling was observed in marginal zone B cells in the spleen, representing one of the few markers for this cell type. The majority of cases of small B-cell lymphoma, diffuse large B-cell lymphoma and lymphocyte predominance Hodgkin's disease were positive for FCRL. However, the number of positive cells varied widely, and in consequence we could not define a cut-off that distinguished subsets of diffuse large B-cell lymphoma. Our results also showed that FCRL tended to be negative in T-cell-rich B-cell lymphoma and in classical Hodgkin's disease. FCRL may therefore represent a novel marker for normal B cells (e.g. splenic marginal zone cells) and may also be useful as a potential marker of B-cell neoplasms.

Aims: In this study, we have examined the occurrence of FcalphaRI-bearing cells in gingival tissue, gingival fluid and blood, in search for possible roles of IgA and FcalphaRI in periodontal lesions., Methods: Gingival biopsies from inflamed and healthy sites were obtained from patients with chronic marginal periodontitis. Sections of inflamed gingiva were examined by immunofluorescence techniques and compared to sections from healthy sites. Smears were made from blood and gingival crevicular fluid and similarly studied., Results: Dense infiltrates of neutrophils with strong expression of FcalphaRI (and FcgammaRIII) were found in connective tissue and epithelium of the apical part of periodontal pockets from diseased sites. In contrast, only few such cells were found in healthy gingiva from the same patients. Neutrophils in gingival fluid, tissue and blood expressed FcalphaRI with similar intensity, whereas the expression of FcgammaRIII was significantly decreased in gingival crevicular fluid. Considerable numbers of bacteria from gingival plaque were found to be covered by IgA., Conclusion: It is suggested that FcalphaRI on neutrophils may play an important rôle in elimination of IgA-opsonized bacteria, both in periodontal tissue and the adjacent pockets.

Polymorphonuclear leukocytes (PMNLs) are the most numerous cell population among the cellular infiltrates in gingival crevicular fluid (GCF) and play important roles in the host-defensive system in the gingival crevices. We determined the percentage of neutrophils, eosinophils and basophils in total PMNLs by light microscopic observation using Randolph-methylene blue staining, then assessed flow cytometric differences in the expression of CR3, Fc gamma RIII, Fc epsilon RII, LFA-1 alpha, and LFA-1 beta on PMNL in GCF and peripheral blood (PB) from 21 patients with adult periodontitis (AP) and 13 healthy donors. Percentages of basophils and eosinophils were higher in GCF than in PB. In both AP patients and healthy subjects, expression of CR3 and Fc epsilon RII was higher while Fc gamma RIII was lower in GCF than in PB. The statistical analysis showed that the expressions of Fc gamma RIII and Fc epsilon RII on GCF PMNLs were lower in AP patients than in healthy subjects. Expressions of LFA-1 alpha and beta on GCF were similar to those on PB PMNLs. PB PMNLs stimulated in vitro with Porphyromonas gingivalis culture supernatant and fMLP displayed an expression pattern of CR3, Fc gamma RIII and Fc epsilon RII on GCF PMNLs. However, C5a and IL-1 failed to induce changes in Fc gamma RIII and Fc epsilon RII. The results indicate that GCF neutrophils are activated, present enhanced adhesion and a decreased IgG-binding ability which would reflect that they are at the terminal stage of activation, and that GCF contains a larger eosinophil fraction than in PB. Moreover, these GCF eosinophils appear to be activated.

Objective: To determine the ability of T lymphocytes and natural killer (NK) cells from patients with systemic sclerosis (SSc) to respond to cytokines and to generate immune effector cells., Methods: The numbers and percentages of peripheral blood T and NK cells were examined by 2-color flow cytometry, and NK and lymphokine-activated killer (LAK) cell function were measured in 4-hour 51Cr-release assays, in 34 patients with SSc. The patients were categorized into 3 subgroups: 10 had diffuse cutaneous disease of less than or equal to 3 years disease duration, 11 had diffuse cutaneous SSc of greater than 3 years duration, and 13 had limited cutaneous disease., Results: Baseline and activated NK and T cell numbers and NK activity were normal in SSc patients. However, mean LAK activity was significantly depressed in all SSc subgroups., Conclusion: Decreased LAK cell function, despite normal numbers of circulating T and NK cells, indicates that SSc patients have poor ability to produce effector cells in response to interleukin-2.

Levels of serum IgE, serum soluble-Fc epsilon RII (S-Fc epsilon RII), and Fc epsilon RII(+) peripheral blood lymphocytes (PBL) were examined in 73 patients with atopic dermatitis (AD) and 17 control subjects with no atopic disease, in order to investigate the correlation of these parameters with AD. AD patients showed increases in IgE, S-Fc epsilon RII and Fc epsilon RII(+)PBL as compared with control subjects. In AD patients, levels of serum IgE and Fc epsilon RII(+)PBL increased as the extent of dermatitis became more severe, while levels of serum S-Fc epsilon RII showed no correlation with the extent of dermatitis. In 8 of the 73 AD patients who showed an improvement in their symptoms with treatment with topical corticosteroids or antihistamine, IgE, Fc epsilon RII(+)PBL, and S-Fc epsilon RII were measured before and after treatment. Fc epsilon RII(+)PBL correlated with disease activity; IgE and S-Fc epsilon RII did not show any such correlation. Patients with elevated IgE levels (IgE greater than 5,000 U/ml) showed low levels of S-Fc epsilon RII. Severely affected cases with a history of respiratory atopy also showed decreased S-Fc epsilon RII levels. It is believed that S-Fc epsilon RII binds to IgE in serum and may neutralize or down-regulate IgE mediated allergic reactions. A low level of S-Fc epsilon RII may cause an elevation of IgE and an exacerbation of the disease.

Granulocyte Fc gamma receptors are important components in the recognition of IgG-coated cells and immune complexes. Two proteins have been identified on resting human granulocytes which function as Fc gamma receptors, Fc gamma RII (CD32) and Fc gamma RIII (CD16). A third protein, Fc gamma RI (CD64), is not constitutively expressed on resting granulocytes, but can be induced by activation with gamma-interferon. We examined the role of these three Fc gamma receptors on human granulocytes in the binding of both IgG-sensitized erythrocytes and soluble oligomeric IgG. In these studies we employed anti-Fc gamma receptor antibodies which complete for the Fc gamma RII and Fc gamma RIII ligand binding sites. Preincubation of granulocytes with saturating concentrations of high-affinity anti-Fc gamma RII monoclonal antibody did not alter the recognition of IgG sensitized human cells by granulocytes. Furthermore, ligand binding studies demonstrated that anti-Fc gamma RII antibody altered neither the number nor the affinity of granulocyte binding sites for human trimeric IgG. In contrast, Fab anti-Fc gamma RIII inhibited the binding of both IgG (anti-D) sensitized human RBCs and IgG sensitized sheep RBCs. Similarly, a reduction in the expression of Fc gamma RIII by treatment with phosphatidyl-inositol specific phospholipase C reduced PMN recognition of IgG-sensitized cells. Also, anti-Fc gamma RIII decreased the number of granulocyte binding sites for human IgG trimer without a change in receptor affinity. Fc gamma RI, which was induced by gamma-IFN, increased granulocyte recognition of both IgG sensitized RBCs and IgG trimer. These data suggest that Fc gamma RIII is the primary Fc gamma receptor on granulocytes which recognizes IgG sensitized RBCs and low molecular weight complexes of IgG. With gamma-interferon activated granulocytes, Fc gamma RI appears to enhance this recognition process.

We report a 38-year-old woman who developed an erythematous nodule on her earlobe after wearing pierced-type 18-carat gold earrings. Biopsy specimens revealed dense cellular infiltration predominantly composed of lymphocytes and plasma cells in the dermis and subcutaneous tissue with formation of lymph follicles. Morphological and immunohistochemical analyses were compatible with lymphadenosis benigna cutis.

The activation state of T and B lymphocytes in the peripheral blood of periodontitis patients may be a reflection of disease activity. We have utilized 2- and 3-color flow cytometric analyses using a new chromophore, peridinin chlorophyll A protein, and conventional dyes, fluorescein isothiocyanate and phycoerythrin, conjugated to monoclonal antibodies against activated lymphocyte surface markers to measure blood lymphocyte subsets from 18 periodontitis patients and 16 periodontally healthy control subjects. Two-color flow cytometric analysis demonstrated that the frequency of CD4+ and CD5+ T cells, CD20+ B cells, and CD16+ NK (natural killer) cells were increased in periodontitis patients. Of particular interest, CD4+ activated "memory" T cells, CD5+ B cells, and CD56+ NK effector cells were increased significantly in periodontitis patients (p less than 0.05). While the relationship of lymphocyte activation to periodontal disease activity remains unclear, there may be potential for using 2- and 3-color flow cytometry to subcategorize periodontitis patients into high- and moderate-risk groups.

The possible influences of ethanol and its metabolic product acetate on the surface expression of HLA class I and class II antigens and CD16 Fc receptors were examined. Fluorescent-labeled monoclonal antibodies and flow cytometry were used to measure these antigens on leukocytes from reference controls, subjects admitted for alcohol detoxification, uremic patients undergoing hemodialysis using Cu-prophan dialyzers and fluids containing 4 to 37 mM acetate, and uremic patients that were not hemodialyzed. In comparison to the controls, the mean intensity of staining for class I antigens was not changed significantly on lymphocytes or monocytes from alcoholics but was depressed on cells from eight of 12 uremic patients. Interferon-gamma above 5 units/ml was detected in less than 15% of plasma samples from controls, uremic patients or alcoholics on admission but was detected in four of eight samples from alcoholics at discharge (2-4 days after admission). The intensity of staining for class II antigens was depressed by more than 50% on lymphocytes from alcoholics and uremic patients. The expression of HLA class I and class II antigens was depressed whether uremic patients were hemodialyzed or not. The percentage of lymphocytes expressing CD16 was depressed in three of seven alcoholics and five of seven hemodialyzed patients. In contrast, the percentage of monocytes expressing CD16 was increased in six of seven hemodialyzed patients and three of five uremic patients not undergoing hemodialysis suggesting activation of monocytes in these patients. Plasma levels of beta 2-microglobulin were elevated by 61% in alcoholics, 50-fold in hemodialyzed patients, and 26-fold in nonhemodialyzed uremic patients.(ABSTRACT TRUNCATED AT 250 WORDS)

The presence of Fc-receptors for IgG, FcRI (CD64), FcRII (CD32) and FcRIII (CD16) in human peripheral nerves was studied by indirect immunofluorescence staining of cryostat sections with monoclonal antibodies (mabs). The mabs 32.2 against FcRI, IV.3 and C1KM5 against FcRII, B1D6 against a 40 kD FcR with low affinity for IgG, and Leu-11b and 3G8 against FcRIII stained a few scattered cells in the endoneurium, apparently monocytes/macrophages. In addition, B1D6 and Leu11b gave a membranous staining of Schwann cells, endothelial cells and perineurial cells. Axons and fibroblasts were not stained by any of the mabs. The FcR may be important in binding immune complexes, in phagocytosis, in the release of lymphokines as well as cytotoxic and inflammatory mediators and in local immunoregulation.

Cerebrospinal fluid (CSF) and peripheral blood (PB) lymphocyte subsets were determined by flow cytometry (FCM) in 15 patients with active multiple sclerosis (MS) and 15 patients with acute inflammatory diseases (ID) of the central nervous system (CNS) in order to establish correlations between the two groups of diseases, as well as between the CSF and PB subsets distribution. A panel of monoclonal antibodies was applied to all the samples: Leu3 (CD4), Leu4 (CD3), Leu2 (CD8), Anti-HLA-DR, Leu11 (CD16). Statistical analysis did not show differences in CD3+ nor in CD3+ DR+ T-cells both in the CSF and PB in the two groups of patients. CD4+ cells were significantly higher in the CSF than in the PB, while CD8+, DR+ CD3- and CD16+ cells were constantly lower in the CSF without differences between the two groups of diseases.

Phenotypic characteristics, and correlations between the expression of membrane NK-associated (NKa) determinants (CD11b, CD16, CD56 and CD57) and T cell receptor (TCR) genotypic patterns, were examined in 25 patients with persistent (greater than 6 months) expansions of CD3+WT31+NKa+ (CD8+ and CD8dim+) lymphocytes. These studies showed that distinct NKa phenotypic profiles were restricted to cases with rearranged TCR configurations and that clonal CD3+NKa+ components could be predicted in most cases by assessing relationships between membrane CD16 and CD56 expression. For all normal NKa subpopulations, there was a high correlation (P less than 0.0001; n = 31) between the expression of these two membrane determinants. Markedly increased CD16 expression by CD3+NKa+ cells, in relation to CD56 (i.e. a high CD16:CD56 ratio), was found exclusively in cases with rearranged TCR (13/16 cases); 2/3 of the remaining cases showing significantly reduced CD16:CD56 ratios and high (greater than 2.0) CD3+CD56+ absolute numbers. In contrast, 7/9 of the germline TCR cases had a normal CD16:CD56 ratio and 2/9 a decreased ratio with low (less than 1.0) CD3+CD56+ absolute numbers. A high ratio of CD16:CD56 expression by CD3+NKa+ lymphocytes was therefore informative for 82% of TCR rearrangements in this series; and analysis of CD16 and CD56 expression was predictive for germline and rearranged TCR configurations in 24/25 persistent CD3+NKa+ expansions.

The phosphatidylinositol (PI) bound proteins (acetylcholin-esterase (ACE), decay accelerating factor (DAF), leucocyte function antigen type 3 (LFA-3) and Fc-receptor type III (FcRIII] were estimated by flow cytometry on blood cells from four patients with paroxysmal nocturnal haemoglobinuria (PNH), nine patients with 'non-PNH' haemolytic anaemia, four patients with aplastic anaemia and a reference group of 15 healthy individuals to assess the applicability of flow cytometric measurements in the clinical mapping of the PNH defect. Estimation of DAF on granulocytes or monocytes offered the highest diagnostic sensitivity and specificity and may constitute an easy screening method for the PNH defect. One PNH patient had a negative Ham's test at the time of study and normal or near normal levels of PI-bound proteins on erythrocytes, but reduced expression of DAF and FcRIII on granulocytes and DAF on monocytes. The analytical and biological coefficient of variation for flow cytometric estimation of PI-bound proteins was in the range of 4.8-13% and 12-24%, respectively. Blood samples should be analysed without delay, since storage produced spuriously high results. The results were expressed as molecules per cell after calibration with commercially available standards and validated by comparison with previously reported results obtained by other methods. It is proposed that this way of reporting flow cytometric results should be generally adopted to facilitate comparison of results between laboratories.

Antisperm antibodies (ASAs) present in sera of infertile men and women have been shown either to promote or inhibit penetration of zona-free hamster eggs by antibody-labelled human spermatozoa. Increased numbers of oolemmal-bound sperm have been noted in association with increased sperm penetration frequencies, following antibody labelling, when compared with antibody-free sperm. The promotion of adherence of ASA-labelled sperm to the oolemma could be mediated through the binding of antibodies to common epitopes present on the sperm and egg surfaces or through Fc-mediated binding to an oolemmal Fc receptor. In support of the latter hypothesis, we report that zona-free hamster eggs bind aggregated human IgG and IgG Fc fragments. The presence of an oolemmal IgG Fc receptor has been confirmed using a rat monoclonal antibody (2.4G2) directed against a murine IgG Fc receptor (Fc gamma RII) as judged both by indirect immunofluorescence and by immunobead binding. In addition, the pre-incubation of zona-free hamster eggs with IgG Fc diminished both adhesion to and penetration of the oolemma by human spermatozoa.

Glycosyl-phosphatidylinositol (GPI) anchored membrane proteins have been reported to be deficient on affected paroxysmal nocturnal haemoglobinuria (PNH) blood cells. In the present study we investigated the deficiency of several GPI anchored membrane proteins on PNH neutrophils (PMN) and monocytes from 10 patients with PNH. Decay-accelerating factor (DAF) and Fc gamma R-III (CD16) on PMN, DAF and CD14 on monocytes, were investigated by two-colour immunofluorocytometry. Neutrophil alkaline phosphatase activity was also assayed on PNH neutrophils. Normal human PMN were always shown phenotypically to be DAF+/CD16+. A DAF-/CD16- subpopulation of PMN was demonstrated in all the patients studied. In six out of the 10 patients, deficiencies of DAF and CD16 were found simultaneously on affected PNH PMN. The percentage of DAF- PMN showed a positive correlation with the neutrophil alkaline phosphatase (NAP) score. However, it should be noted that, in four out of the 10 patients with PNH, a DAF+/CD16- subpopulation of PMN was also clearly found. This may indicate that the deficiencies of DAF and CD16 on PNH PMN are heterogeneous. Normal human monocytes were demonstrated to be DAF+/CD14+, whereas PNH monocytes consisted of subpopulations of DAF+/CD14+ and DAF-/CD14-. In the same patients with PNH, the deficiencies of DAF on PMN and monocytes correlated well with each other. These results suggest that, at least in some patients with PNH, the mechanisms which induce the membrane defects of PNH blood cells are heterogeneous.

Receptors for IgG and complement are present on the plasma membrane of functionally mature blood neutrophils. Neutrophilic precursors lack these membrane receptors, which may account for their diminished phagocytic capability. In this study, myeloid precursors from human bone marrow were examined for the presence and activity of membrane receptors for IgG and activated complement. Morphologic identification by light microscopy of neutrophilic cells are made by rosetting techniques and chloroacetate esterase cytochemical staining and at the ultrastructural level by peroxidase reactivity. This study showed the Fc receptor was the only membrane marker on the myeloblasts and that the number of cells with the receptor increased with maturation. Functional investigation of the Fc receptor indicated that its presence on early myeloid cells was insufficient to induce IgG-mediated ingestion. Phagocytosis via the Fc receptor was not acquired until the metamyelocyte stage. Complement receptors, C3d and C3b, appeared later than the Fc receptor. The C3d receptor, detected first on the promyelocyte, remained relatively constant throughout maturation, whereas the C3b receptor acquired acquired at the myelocyte stage increased with maturation. These data provide evidence that distinct membrane changes occur during normal myeloid cell maturation and that the presence of these membrane receptors is not sufficient for Fc-mediated ingestion to occur.

The presence of receptors for IgG Fc and fragments of C3 on primary cultures and cryostat sections of normal and rheumatoid synovial tissues was assessed. Significant proportions of large rounded cells with asteroid projections found in such cultures had receptors for both IgG Fc and fragments of C3. Moreover, Gram negative bacteria that had fixed complement, but not EAC, bound in a linear fashion on the superficial layers of synovial cryostat sections. On the basis of morphologic and histochemical criteria, the cultured cells bearing these receptors were tentatively determined to represent a subset of synovial lining cells. The possible role of such receptors on synovial lining cells in the pathogenesis of rheumatoid arthritis is discussed.

The present in vitro study concerned the phagocytosis and intracellular killing by polymorphonuclear cells (PMN) of 5 patients with rheumatoid arthritis (RA) and 12 patients with Felty's syndrome (FS). PMN phagocytosis was assessed by microbiologic and morphologic methods, and intracellular killing was measured independently of continuous phagocytosis of viable bacteria (Staphylococcus aureus). PMN from patients with RA or FS ingested S aureus opsonized with immunoglobulins and complement as effectively as did PMN from healthy donors. However, the capacity of patient PMN to ingest S aureus opsonized with sera lacking complement activity, e.g., heat-inactivated donor serum and the sera of 2 patients with FS, was lower than that of healthy donor PMN. This decreased ingestion is associated with diminished expression of Fc receptors on the membrane of PMN from patients who have RA or FS. As with sera lacking complement activity, decreased capacity to ingest S aureus was observed after preloading donor PMN with immune aggregates, which also decreased the expression of Fc receptors. PMN from patients with RA or FS were found to be as active in killing S aureus as cells from healthy donors.

In immunologically mediated disorders such as systemic lupus erythematosus and experimental serum sickness, immunoglobulin and complement amy be localized in the choroid plexus. This report demonstrates the presence of binding activity for the Fc fragment of IgG in 34 of 36 samples of human choroid plexus. We suggest that the number, distribution, and avidity of these Ig receptors may modulate the occurrence and/or severity of central nervous system symptoms in patients with immunologically mediated systemic diseases.

An immunological surface marker study was performed on 13 patients with a variety of myeloid leukaemias. It was shown that expression of the receptor for the Fc of IgG (gamma FcR) starts to take place at the promyelocyte stage, and that the receptor is present on more mature granulocytic cells, but is absent from myeloblasts. Myeloblasts and promyelocytes are negative for the complement receptor CR2. Monoblasts, unlike myelobasts, were shown to express a gamma FcR and, to a lesser extent, CR2. Receptor expression therefore appears to be an earlier event in monocytic development. The possible diagnostic value of immunological marker studies in myeloid disorders is considered.

A patient having a B cell chronic lymphocytic leukaemia was treated with a monoclonal anti-idiotypic antibody (MoAb anti-id). Up to 24.5 g of MoAb anti-id has been administered to the patient over a period of 1 year without serious side effects. Despite a substantial amount of serum idiotype (id = 100 micrograms/ml) and a low expression of id on the tumour cells (+/- 6000 molecules per cell) clearance of serum id and a marked tumour reduction was obtained. Therapy resistance developed and coincided with a decreased clearance rate of circulating id-anti-id immune complexes and an increased modulation of cellular id expression, in vivo. This suggests that a decreased clearance rate of anti-id coated tumour cells provided more time for id modulation in vivo, resulting in therapy resistance. Therefore, the overall capacity of the natural effector system may have an important influence on the ultimate therapeutic effect of immunotherapy with MoAb anti-id. Although the partial remission obtained was not long-lasting, this study shows that MoAb anti-id therapy can be effective even when id expression on the tumour cells is low and a substantial amount of serum id is present.

To determine the role of T lymphocytes (TL) that bear Fc receptors for IgG (T gamma +) and IgM (T mu +) and of those that do not (T gamma- and T mu-) in the elaboration of granulocyte-macrophage colony-stimulating activity (GM-CSA), we coincubated TL or the TL subpopulations in varying proportions with a constant concentration of autologous monocyte-macrophages (M phi) along with methanol extraction residue of BCG (MER). These conditioned media (CM) were assayed for GM-CSA. M phi and TL interacted maximally at 1:3-1:6 ratios, significantly less so at a 1:9 ratio. Coincubation of M phi with T gamma- fraction markedly enhanced GM-CSA elaboration at all M phi:T gamma- ratios, progressively increasing colony-stimulating activity as the proportion of T gamma- cells increased. M phi interacted with the T gamma- fraction significantly better (P = 0.001) at all the ratios tested than it did with the T gamma- mu + or T gamma- mu- subsets, suggesting that the T gamma- mu + and T gamma- mu- subsets must interact. Coincubation of the T gamma + fraction synergistically enhanced GM-CSA elaboration only at M phi:T gamma + ratios of 1:1.5 and 1:3. Further increases in the proportion of T gamma + cells rapidly and progressively decreased the capacity of the CM to stimulate granulocyte-macrophage colony-forming cells (GM-CFC). Also, inclusion of Tgamma+ cells in the coincubation mixtures of M phi and T gamma- fraction significantly suppressed GM-CSA elaboration. Dose-response curves and CM-mixing experiments revealed that the CM from coincubation of M chi and T gamma+ not only contained smaller amounts of stimulating factors but also contained a GM-CFC inhibitor. Experiments also demonstrated that the suppressor subpopulation enriched with the T gamma+ fraction was radiosensitive. These results suggest that the elaboration of GM-CSA is controlled by helper and suppressor subpopulations that are enriched with T gamma- and T gamma+ fractions, respectively. Furthermore, the suppressor effect is radiosensitive.

The phagocytosis and intracellular killing by synovial fluid (SF) polymorphonuclear cells (PMN) of 10 patients with rheumatoid arthritis was studied. PMN phagocytosis was assessed by morphologic and microbiologic methods and intracellular killing was measured independently of continuous phagocytosis of Staphylococcus aureus. Phagocytosis of S aureus by SF PMN or peripheral blood (PB) PMN was as effective in the presence of synovial fluid as in the presence of serum. On average, SF PMN ingested S aureus opsonized with synovial fluid and serum more efficiently than patient or donor PB PMN did. Enhanced ingestion of S aureus was associated with increased expression of C3 receptors on the membrane of SF PMN. In the presence of heat-inactivated synovial fluid, the capacity of SF PMN to ingest S aureus was greater than that of patient or donor PB PMN. Under these conditions, phagocytic activity was correlated with Fc receptor expression. SF PMN was found to be as active in killing S aureus as PB PMN from healthy donors.

Until recently, human blood neutrophils (PMN) and monocytes have been considered to be homogeneous cell populations. However, much evidence has accumulated on their functional heterogeneity. This functional heterogeneity suggests the existence of different subsets of myeloid cells analogous to T and B subsets of lymphoid cells. The goal of this study was to investigate this question of myeloid subsets by examining myeloid cells for cell surface reactivity for IgG and complement (C). Normal PMN and monocytes were examined from 60 subjects for the presence of two types of IgG-Fc receptors and two activated C components, C3b and C3d. Most PMN and monocytes showed Fc receptor activity for rabbit IgG (Fc-R). In addition, the majority of monocytes but very few PMN reacted with human IgG (anti-Rh0) coated Rh-positive erythrocytes (Fc-H). Most PMN and monocytes showed C receptor reactivity for C3b, but only a minor subpopulation of both myeloid cells had C3d receptors. These data provide evidence that human blood myeloid cells may be composed of subsets with different membrane marker reactivities.

The distribution of T gamma lymphocytes in the peripheral blood of one group of rheumatoid patients and in the synovial fluid in a second group was determined. The results were compared to those found for peripheral blood (PB) lymphocytes of normal subjects and for synovial fluid lymphocytes of osteoarthrosis and meniscitis patients. Besides recording percentage and absolute number, we also used cytofluorographic analysis to determine individual capacity of PB T gamma cells to bind heat-aggregated IgG (agg-IgG). The following results were found: 1) there is no significant difference between the percentage and absolute number of PB T gamma lymphocytes of rheumatoid arthritis (RA) patients and those of controls, 2) individual RA PB T gamma cells had a greater number and/or avidity of Fc receptor for IgG than those cells of controls, and 3) the percentage of RA T gamma lymphocytes in synovial fluid, revealed by IgG-EA ox rosetting, is significantly lower than that found in control patients. The factors that may determine a similar lymphocyte picture in RA are discussed.

The clinical course of Ph+CML and their terminal blastic stage is described in the following case histories. During blastic phase, cell surface markers, terminal deoxynucleotidyl transferase (TdT) activity, and flow cytometric measurements were used or determination of the blast cell phenotype which was undifferentiated by morphological and cytochemical criteria. A high proportion of blast cells expressed Fc receptors for IgG, TdT activity was normal in both children and RNA measurements of single cells flow cytometry showed a high RNA content in the majority of blasts. These findings are compatible with the phenotype seen in the myelomonocytic leukemias. Flow cytometry appears to be a useful adjunct to immunological methods and TdT activity for the rapid characterization of CML in blastic phase.

A method for rosetting neutrophils was developed and optimal rosetting conditions determined. The adhesive properties of neutrophils and their ability to form rosettes were studied for cells in the circulating pool, and following exercise when the circulating pool had been enriched by neutrophils from the marginated pool. We found the marginated pool to be the same as the circulating pool in terms of rosetting subpopulations and the in vitro adhesive properties of these subpopulations, indicating that the two pools can be considered kinetically as one. We also showed that non-rosetting neutrophils can develop the ability to form rosettes following adhesion to glass in the presence of autologous serum.

Among peripheral blood T cells from 25 patients with myeloma, % OKT8+ suppressor cells were increased in all but two patients (mean 63 +/- 12%; normal 34 +/- 8%), but were present in normal absolute numbers (mean 0.5 +/- 0.3 x 10(9)/l; normal range 0.2-0.6 x 10(9)/l). OKT4+ helper cells were reduced in relative and absolute numbers (mean 40 +/- 12%, 0.3 +/- 0.2 x 10(9)/l; normal 64 +/- 8%, 0.6-1.4 x 10(9)/l). Similar results were obtained in treated and untreated cases, and in patients of different clinical stage. In the 12 patients tested, gamma Fc-rosetting T cells were present in normal numbers (mean 28 +/- 10%; normal 34 +/- 10%). In four patients with IgM disease, similar, but less marked, changes in monoclonal antibody-defined T-cell subsets were observed. The findings are discussed in relation to those in other B-cell malignancies, and it is suggested that imbalances of OKT4+ helper/OKT8+ suppressor cells may be important in the immune suppression of many of these disorders.

In six cases of both hairy-cell leukaemia (HCL) and chronic lymphocytic leukaemia (CLL) it was shown that the pathological cells express receptors for the Fc portion of IgA (RFc alpha). Many of the cells simultaneously expressed receptors for IgA, IgM and IgG, and blocking studies showed that these are distinct receptors. In contrast, the malignant cell of most of the various other B-cell leukaemias studied showed low levels of RFc alpha expression. The significance of the results is briefly discussed and it is suggested that receptor expression may be a marker of certain stages of B-cell development.

Acid alpha naphthyl acetate esterase (ANAE) and combined ANAE-chloroacetate esterase cytochemistry was performed on 121 bone marrow aspirates from primary myelodysplastic syndromes (MDS) and a secondary dysplasia-megaloblastic anaemia (MA). The investigation demonstrated the presence of abnormal ANAE positive granulocyte populations in a significant proportion of cases. These cells, in which the staining patterns were characterized by atypical granular ANAE positivity and double ANAE-chloroacetate reactions, were shown immunologically to lack the receptor and antigenic characteristics of monocytes and morphologically to be granulocytes. Isoelectric focusing, however, indicated that the atypical esterase cytochemistry of these granulocytes was due to the presence of markedly increased concentrations of ANAE isoenzymes usually found in monocytes. Atypical ANAE-staining granulocytes were particularly evident in MDS marrows showing sideroblastic erythroid changes, whilst in MA they were mainly seen in cases of intermediate severity. It is suggested that these cells are associated with dysmyelopoietic changes in both malignant and non-malignant conditions.

Twenty-one patients are described with a proliferation of morphologically mature T lymphocytes. The clinical course was chronic in most, and splenic enlargement the main clinical finding; skin involvement and lymphadenopathy were rare. The mean lymphocyte count at presentation was 8 X 10(9)/1 (range 0.75-24 X 10(9)/1). Nineteen of these patients showed some form of cytopenia (18 neutropenia, two red cell aplasia, eight thrombocytopenia) and one had hypogammaglobulinaemia. Seven patients had long-standing arthropathy serologically proven to be rheumatoid arthritis and these had previously been considered to have Felty's syndrome. Five of the group have died (three with an aggressive course), but most have remained stable for prolonged periods with a slow increase in peripheral lymphocyte count and marrow infiltration. Spontaneous regression was never observed but in two patients a prolonged remission was achieved by chemotherapy. The lymphocytes were morphologically and phenotypically homogeneous at presentation and remained so post-splenectomy; they contained azurophilic granules, stained with acid phosphatase but weakly or not at all with alpha napthyl acetate esterase. Membrane phenotyping shows the majority of the cells to be E+, Fc gamma+, OKT3+, OKT8+. Most cells do not stain with OKT1-like reagents and a significant number express HLA-Dr. From these and other reported cases it is clear that this condition represents a distinct entity resulting from the expansion of a subset of cytotoxic/suppressor T cells--the question of the benign or neoplastic nature of the disease remains open. Using T cell-specific antisera and E-rosetting techniques, a small percentage of CLL cases have been shown to be of T-cell origin (TCLL) (Dickler et al, 1973; Lille et al, 1973). Estimates of the percentage vary but in most series T-CLL has been diagnosed in less than 5% (Brouet & Seligmann, 1981), and this is supported by date from the M.R.C. Leukaemia Unit which found T-CLL in only 1.5% of 600 cases of CLL examined by marker studies (D. Catovsky, unpublished). Amongst the published reports of T-CLL a variety of clinical and morphological entities have been described including T prolymphocytic leukaemia (TPLL) (Brouet et al. 1975) and adult T cell disease in Japanese (Uchiyama et al, 1977) and West Indian Caribbean groups (ATLL) (Catovsky et al, 1982). In the original series of Brouet & Seligmann (1981) the group was defined as presenting in middle age with marked hepatosplenomegaly, some lymphadenopathy, skin involvement and with an aggressive disease course; peripheral blood and marrow lymphocytosis were variable.(ABSTRACT TRUNCATED AT 400 WORDS)

T lymphocytes from 22 patients with hairy-cell leukaemia (HCL) were assessed on the basis of their ability to bind the Fc receptors for IgM (T mu) or IgG (T gamma), and by the capacity to react with OKT monoclonal antibodies. T-cell subsets defined by the presence of Fc receptors for IgM or IgG showed an overall increase in the proportion of T gamma cells and a non-significant decrease of T mu cells, regardless of the clinical state of the disease. Results with monoclonal antibodies showed that in patients with HCL in clinical remission T-cell subsets were normally balanced, while in patients with active disease the distribution and absolute number of T-cell subpopulations appeared markedly impaired, with a significant increase of OKT8 positive cells (suppressor/cytotoxic) and a significant reduction of OKT4 positive cells (helper/inducer) compared both with active disease patients and with normal controls. The OKT4+/OKT8+ ratio was also significantly reduced in patients with active disease compared with those in clinical remission and with controls (0.96 v 1.63 and v 1.94, respectively). Our findings confirm the heterogeneity of T-cell subset positivity defined by monoclonal antibodies and by Fc mu and Fc gamma receptors and suggest that in patients with HCL the distribution of OKT4 and OKT8 positive cells is closely correlated to the clinical state of the disease.

Multiplication of Balb/C mouse resident peritoneal macrophages was observed, when all the cells collected in the washing fluid of the peritoneal cavity were seeded in appropriate culture medium. This multiplication began only after the appearance of a confluent monolayer of flat cells, referred to as "mesothelial" cells. The macrophages produced passed from the "mesothelial" cell layer to the suspension and could be passaged indefinitely. Each culture underwent an identical cycle of events which always included the appearance of a confluent monolayer of "mesothelial" cells. The cells transferred were characterized by their ability to phagocytose yeasts, and by the presence of Fc receptors and cytoplasmic non-specific esterases.

The relationship between alpha-interferon receptor (alpha IFNR) numbers, B-cell-antigen expression and clinical stage was determined in 35 cases of typical chronic lymphocytic leukaemia (CLL). alpha IFNR numbers were shown to be low in patients with advanced disease and high in those with a more favourable prognosis. The B-cell activation antigen CD 23 was similarly related to stage, being high in more favourable disease. Also, alpha IFNR expression was directly related to CD 23 positivity, but alpha IFN binding was not inhibited by CD 23 monoclonal antibody. There was no correlation between CD 19, 20, 22 and 24 antigen expression and either alpha IFNR numbers or clinical stage. Since CD23 antigen expression is a feature of B-cell activation, we suggest that high CD23 and alpha IFNR positivity are manifestations of an activated cell phenotype and that cell activation in CLL is a feature of favourable disease.

Neutrophils that bear receptors for the Fc portion of immunoglobulin G have been demonstrated to be more active in assays of adherence, aggregation, and chemotaxis compared to Fc receptor-negative cells. We examined the relationship of neutrophil Fc receptor activity and cell-cell adherence or aggregation induced by phorbol myristate acetate. In contrast to 1-isoproterenol, isobutyl-methyl-xanthine, and dibutyryl cAMP, each of which inhibited Fc receptor activity and neutrophil aggregation, theophylline significantly impaired aggregation without affecting Fc receptor activity. The selective beta-2 agonist, metaproterenol, and 8-Bromo cAMP failed to inhibit Fc receptor activity or neutrophil aggregation. Three known inducers of neutrophil intracellular cyclic AMP, PGE1, PGE2, and cholera toxin, also did not inhibit Fc receptor activity. Inhibition of Fc receptor activity by 95% in the presence of purified Fc fragments did not affect neutrophil aggregation. Similarly suppression of Fc receptor activity by purified Fc fragments did not inhibit neutrophil adhesion to nylon fiber columns. These data demonstrate that the Fc receptor does not mediate phorbol myristate acetate-induced cell-cell adhesion and is not necessary for optimal neutrophil adhesion to nylon fibers. Our results are consistent with the possibility that the reversible inhibitory activity of beta-adrenergic agonists on rosette formation may be a steric effect rather than a metabolic effect. These data tend to dissociate Fc receptor activity, neutrophil aggregation, and adhesion and support the hypothesis that the Fc receptor may be a marker of neutrophil heterogeneity rather than a component necessary for optimal neutrophil aggregation or adhesion.

Experiments were undertaken to determine whether the depression of natural killer (NK) activity previously observed in the peripheral blood lymphocytes (PBL) of leukaemia patients in remission extended to NK-like precursors in the blood. T-lymphocytes (E+) from leukaemia patients and normal subjects were depleted of IgG Fc-receptor-bearing (gamma FcR) fresh NK cells by passage over immune complex-coated monolayers. gamma FcR - E + PBL were cultured alone or with DAUDI cells. On day 5 of culture, cytotoxicity toward the NK-sensitive cell lines K562 and MOLT-4 was evaluated in the responder lymphocytes of leukaemia patients and controls. Negligible NK-like cytotoxicity was found in both FcR - E + PBL responder populations cultured alone. By contrast, stimulation with DAUDI induced high levels of K562 and MOLT-4 cytotoxicity in leukaemia as well as in normal responder cells. Complement-mediated cytotoxicity experiments using various McAb demonstrated that in both normal and leukaemia cultures NK-like effectors react with the pan-T OKT3 McAb and with the OKT11 McAB directed to the SRBC receptor, but not with Leu 1 1b and OKM1 McAbs, directed against antigens expressed on peripheral blood NK cells. Fractionation of the responder cells on discontinuous Percoll gradients showed that most of this activity was present in the highly dividing blast cell fraction.

Platelet glycoprotein I (GPI) is known to be required for the interaction of platelets with ristocetin and factor VIII:von Willebrand factor (VIII:vWf). However, its role as Fc receptor is not clear. Some studies have shown that enzymatic removal of GPI destroys the ability of platelets to react with VIII:vWf but not their ability to bind Ig G (IgG). Others have shown that IgG immune complexes which block the Fc receptor also inhibit VIII:vWf interaction with platelets. This subject has been re-examined by testing the ability of platelets with reduced amounts of GPI to aggregate and undergo the release reaction in response to stimuli which act at the platelet Fc receptor. Platelets from two patients with Bernard-Soulier syndrome, congenitally deficient in GPI, both aggregated and released 14C-serotonin normally when exposed to latex particles coated with IgG. Levels of GPI were decreased experimentally in normal platelets by treating them with chymotrypsin. Platelets treated in this manner did not aggregate or release [14C]serotonin in response to ristocetin-VIII:vWf. They did, however, both aggregate and release when incubated with heat-aggregated IgG, antigen-antibody complexes or latex particles coated with IgG. Thus the presence of GPI is not a prerequisite for platelet stimulation via the Fc receptor.

Thirteen cases of acute monocytic leukemia (AMoL) were studied morphologically, cytochemically, and immunologically in an attempt to determine similarities and/or differences between acute monocytic and lymphocytic leukemias. Single class surface immunoglobulins (IgG kappa) were seen in six cases. These markers are thought to represent serum immunoglobulins attached to the leukemic monocytes via the receptors for the Fc portion of immunoglobulin and are not synthesized by the cells as is the case with B lymphocytes. Receptors for complement were also noted. It appears that surface immunoglobulins and receptors for the Fc portion of the immunoglobulin and complement, which are found on several classes of normal lymphocytes and monocytes, may also be found on leukemic monocytes. Antisera to B lymphocytes, detecting HlA-DRw antigens, also reacted with some of the leukemic monocytes.

Morphological, surface-marker and culture studies were performed in three patients who had in common neutropenia and an excess of lymphocytes in the bone marrow, but who differed from each other in certain regards such as age and peripheral lymphocyte numbers. All three patients had an increased proportion of E-rosetting cells bearing Fc receptors for IgG. These cells were shown to be T lymphocytes by staining with monoclonal anti-T-cell sera and their subset phenotype was established as OKT4- OKT8+; in addition, a variable proportion of the cells was Ia+. The functional significance of this expanded subpopulation of T cells was not clear, but it was shown that they did not inhibit colony formation in vitro.

The IgG-Fc binding activity and binding sites on the cell surface of streptococci, strains AR1 (group A) and G148 (group G), and Staphylococcus aureus strain Cowan I were examined by hemagglutination (HA) and immunoelectron microscopic methods. No distinct difference was observed in the HA activity among these three strains. However, the strains differed in the distribution of Fc receptor. Cowan I cells (having protein A) were heavily covered with two layers of ferritin particles, whereas AR1 cells were heavily covered with a single, rough layer of ferritin particles. G148 cells (having protein G) were labeled with a relatively thin, rough ferritin layer. The trypsin susceptibility of the Fc receptors of the AR1 strain was much higher than that of the G148 strain. These results suggest that both streptococcal strains are distinctly different in the arrangement or in the conformation of the Fc receptor from the Cowan I strain. It is also suggested that the Fc receptor molecules of the streptococcal strains differ from each other not only in conformation but also in trypsin susceptibility.

We studied three patients with cyclic thrombocytopenia which occurred in phase with the menstrual cycle. The platelet count in each patient reached a nadir of 5-20 x 10(9)/l at the onset of menses. Thrombocytopenia was associated with bruising, epistaxis and menorrhagia and was followed 5-14 d later by normal or elevated platelet counts (up to 900 x 10(9)/l). Repeat bone marrow examinations performed at the time of reduced platelet counts showed megakaryocytic hyperplasia. 111In-platelet-disappearance from the circulation was measured in one patient; T50, time to half activity, was shortened to 0.7 d during the period of thrombocytopenia and was prolonged to 3.2 d when the platelet count increased (normal platelet T50 is about 4.8 d). In two of three patients platelet-associated anti-glycoprotein Ib autoantibodies were present and remained elevated despite normalization of the platelet count. In both of two patients the decrease in platelet count at the onset of menses was associated with an increase in the expression of monocyte Fc gamma receptors. Based on the reported capacity of oestrogenic hormones to modulate macrophage Fc gamma receptor expression, we propose that hormonal changes during the menstrual cycle may alter the Fc gamma receptor-mediated clearance of antibody-coated platelets by macrophages, modulate platelet survival, and cause cyclic thrombocytopenia.

Human T mu lymphocytes are detected in a histochemical reaction with glycyl-proline-4-methoxy-beta-naphthylamide-peptidase (DAP IV; EC 3.4.14.4). DAP IV occurs in 59.4 +/- 8.25 of human T lymphocytes in blood and marrow. Direct biochemical assays were in accord with the cytochemical findings. DAP IV-positive lymphocytes accounted for 89.5 +/- 0.6% of T-lymphocytes bearing Fc receptor for IgG contained 11.3 +/- 8.3% T-lymphocytes bearing Fc receptor for IgM.