Con A-induced suppressor cell activity and T-lymphocyte subpopulations in peripheral blood lymphocytes of patients with rheumatoid arthritis and juvenile rheumatoid arthritis

Altered T lymphocyte signaling in rheumatoid arthritis

Synovial and peripheral blood T cells from patients with rheumatoid arthritis are functionally deficient. This may be secondary to their reduced cytokine (e.g. interleukin-2) synthesis. We have investigated the possibility of an alteration in pathways common to interleukin-2 production and proliferation in peripheral blood T cells from patients with active rheumatoid arthritis. Intracellular calcium levels ([Ca2+]i) were analyzed by flow cytometric methods in Indo1-loaded T cells. These were purified by negative selection from patients or age/sex-matched controls, and stimulated with phytohemagglutinin-P or anti-CD3. Rheumatoid [Ca2+]i responses to both stimuli were reduced (p < 0.005). Patient cell samples included a larger proportion of non-responding cells, but even in the responsive population the magnitude of the response in rheumatoid cells was impaired compared with those in normal cell samples (p < 0.0001) for both stimuli. Proliferation responses were also impaired (p < 0.005), and there was a positive correlation between the paired [Ca2+]i elevation and proliferative responses for both stimuli. CD2 and CD3 expression were normal, and the proportions of CD4, CD8 and CD45RO and CD45RA subsets were also unaffected by disease. Thus a signaling defect downstream of CD2 or CD3 surface molecules may contribute to functional deficiencies in rheumatoid T lymphocytes. This effect is not due to non-steroidal anti-inflammatory drugs which some patients were taking. We have demonstrated similar alterations in [Ca2+]i responses and proliferation in a smaller study of patients with inflammatory bowel disease, indicating that such changes might be present in other chronic inflammatory states.

Increment of CD8S6F1 cells in synovial fluid from patients with rheumatoid arthritis

OBJECTIVE

To investigate the role of CD8 cell subsets in the pathogenesis of rheumatoid arthritis (RA) and the phenotypes of T cells adherent or non-adherent to the target cells (endothelial cells and synovial cells) pre-treated with IL-1 beta.

METHODS

The expression of S6F1 on CD8 cells and that of an activation marker on CD8 cells and CD8 cell subsets was evaluated in specimens of peripheral blood and synovial fluid obtained from 15 patients with RA and 10 with osteoarthritis (OA) using a two- or three-colour immunofluorescence method for analysis.

RESULTS

The percentage of CD8S6F1 cells among CD8 cells in synovial fluid was significantly greater than that of peripheral blood. Synovial fluid from RA patients had a greater percentage of CD8S6F1 cells compared with either peripheral blood of matched patients or synovial fluid of OA patients. The percentage of CD8HLA-DR cells in synovial fluid was markedly greater than that in paired samples of peripheral blood in patients with RA. In the CD8S6F1 cells from both groups of patients, synovial fluid showed an increased percentage of HLA-DR cells compared with peripheral blood. Similar results were observed in CD8 cells lacking S6F1 expression (CD8S6F1-) from both groups of patients. There was no significant difference in the percentage of HLA-DR cells between CD8S6F1 and CD8S6F1- cell populations in peripheral blood. In contrast with peripheral blood, in synovial fluid of RA patients the percentage of HLA-DR cells in the CD8S6F1 cell population was markedly greater than that in the CD8S6F1- population. However, the percentage of HLA-DR cells in both cell populations was similar in synovial fluid of OA patients. In both the endothelial and the synovial cell adhesion assays, the percentage of CD8S6F1 among CD8 cells and the mean fluorescence intensity of S6F1 antigen on CD8S6F1 cells were significantly greater in the adherent T cell population than that in the non-adherent T cell population.

CONCLUSION

These results suggest that increased expression of S6F1 antigen and the increased percentage of HLA-DR cells on CD8 cells in synovial fluid may be responsible for the migration of these cells into inflamed synovial tissues, and for cellular interactions between these cells and synovial cells or the extracellular matrix.

Immunological aspects of juvenile rheumatoid arthritis

This article reviews the evidence from recent studies on immunological abnormalities associated with pathophysiologic mechanisms operating in three clinical subtypes of juvenile rheumatoid arthritis (JRA) (polyarticular, pauciarticular and systemic). The main discussion is focused on three hallmarks of immunopathological studies. First, abnormalities in phenotype and function of lymphocytes from peripheral blood and inflamed synovium are discussed. The aberrations of lymphocytes are elucidated by T and B cells expressing phenotypic cell-markers such as CD20, CD21, CD4, CD8 and DR in association with different subtypes and disease activity. The functional imbalance and impairment of T and B cells are mainly observed by abnormal proliferation and/or in vitro Ig production in response to mitogens and alloantigens. Second, because the appearance of rheumatoid factors (RF) in serum indicates that the pathogenesis of JRA may be based on the autoimmune mechanism, the prevalence of RF including IgM, IgA and IgG isotype, hidden IgM RF and cross-reactive idiotype RF, and their characteristic properties are discussed. Moreover, specific auto-antibodies (antinuclear antibodies and others) for JRA are illustrated in this paper. Third, the production of various pro-inflammatory cytokines resulting in the release of tissue-damaging chemical mediators is also discussed. This may play a central role in the generation of systemic inflammation and joint involvement in JRA.

Inflammatory synovial T cells in different activity subgroups of patients with rheumatoid arthritis and juvenile rheumatoid arthritis

Mononuclear cells were eluted from synovial membranes of 39 patients with rheumatoid arthritis and 12 patients with juvenile rheumatoid arthritis. A considerable cell loss, about 50% or more, was seen during the various isolation steps. The CD4/CD8 ratio just after enzyme treatment (stage I) was significantly higher than at later stages, i.e. after removal of adherent cells (stage II, p less than 0.05) and after Isopaque Ficoll gradient centrifugation (stage III, p less than 0.01). This indicates a selective loss of CD4+ cells during isolation. In addition, stages I and II had higher CD4/CD8 ratios than peripheral blood of normal controls (p less than 0.01 and p less than 0.03), but not significantly higher than in peripheral blood of patients (p greater than 0.05). The CD4/CD8 ratio in eluted synovial membrane cells did not differ between patients with high and patients with low disease activity (p greater than 0.05). No correlation was found between any of the CD4/CD8 ratios and individual disease activity variables. Furthermore, a laboratory activity index and a disease outcome index were determined for each patient and no correlation was found between these indices and the CD4/CD8 ratios.

Phenotypes of peripheral blood T lymphocytes in rheumatoid arthritis and juvenile rheumatoid arthritis. Findings in patients with varying disease activity and clinical subgroups

The percentage of T4 and T8 positive cells in peripheral blood of 78 patients with rheumatoid arthritis (RA) and 26 patients with juvenile rheumatoid arthritis (JRA) was determined using a rosette technique. The T4/T8 ratio +/- SEM (standard error of the mean) in the RA patients was increased, 2.02 +/- 0.09, as compared with normal blood donors, 1.71 +/- 0.06 (p less than 0.02). The subgroups of RA patients who had a significantly increased T4/T8 ratio were ANA positive patients (p less than 0.02) and patients on no medication (p less than 0.05). In the total group of JRA patients the T4/T8 ratio was 2.01 +/- 0.12 versus 1.75 +/- 0.08 in controls (p = 0.061). Polyarticular JRA patients had an increased T4/T8 ratio as compared with controls (p less than 0.05) while patients with the pauciarticular form had a normal ratio (p greater than 0.10). No correlation between the T4/T8 ratio and a disease outcome index, a laboratory activity index, ESR, WBC, platelet count, hemoglobin, serum albumin, age and disease duration was found (K less than +/- 0.20, p greater than 0.10).

Impaired mitogen-induced interferon-gamma production in rheumatoid arthritis and related diseases

Peripheral blood lymphocytes from patients with rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), progressive systemic sclerosis (PSS), Reiter's disease, osteoarthritis, and from healthy volunteers were investigated for interferon-gamma (IFN-gamma) production after mitogen activation. Phytohaemagglutinin stimulation revealed an impaired IFN-gamma production in RA, SLE, and PSS but normal levels in Reiter's disease and osteoarthritis. In RA this deficiency was also seen after pokeweed mitogen, OKT3, and concanavalin A activation. No major differences were found in interleukin 2 (IL-2) production and cell proliferation. The IL-2 receptor expression was reduced on stimulated RA lymphocytes. The deficient IFN-gamma production was compensated in RA by co-stimulation of PHA or OKT3 with phorbol myristic acetate (PMA). In addition, the combination of the calcium ionophore A 23187 and PMA induced a strong IFN-gamma secretion in all patient groups and in the controls.

Immunological abnormalities in juvenile chronic arthritis

The immunological alterations that have been reported in juvenile chronic arthritis are reviewed. Their role in patient management and classification as well as their possible etiopathogenetic relevance are discussed.

Characterization of the defective autologous mixed lymphocyte response in rheumatoid arthritis

In order to characterize the autologous mixed lymphocyte response (AMLR) in patients with rheumatoid arthritis (RA) and to define the relationship with disease activity, peripheral blood T lymphocytes were stimulated with either a B lymphocyte-enriched (B cells) or a macrophage-enriched (macrophages) population. A significant reduction (P less than 0.01 to P less than 0.001) of T cell proliferation stimulated both by B cells and macrophages was observed in patients with active disease. The B lymphocytes were significantly less stimulatory (P less than 0.02 to P less than 0.001) than macrophages in the patients compared with the controls. In the normal controls, macrophages in higher concentrations were capable of suppressing the B lymphocyte-stimulated AMLR, but macrophages from patients with RA were not excessively suppressive. A significant association (P less than 0.02) was observed between disease activity and the AMLR. Using the B-enriched population, the AMLR proliferative response was significantly associated (P less than 0.001) with the production of interleukin-2. Defects in proliferation could only be partially restored by the addition of interleukin-2. These data indicate that the defective AMLR observed in patients with RA is related to disease activity and is associated with altered cellular interactions among T lymphocytes, macrophages, and the B lymphocyte-enriched population.

Polyglandular autoimmune syndromes

One of the basic caveats in endocrinology is that glandular abnormalities tend to occur together. Continued suspicion of other glandular hypofunction should be maintained in following patients with any type of endocrine gland hypofunction, since the risk of multiple glandular involvement is significant. Family members should be alerted to the high prevalence of endocrinopathies especially among first-degree relatives of patients with polyglandular autoimmune disease. Parameters such as antiorgan antibodies, although occasionally helpful, have not been shown to be consistently useful in predicting the future development of clinical organ-specific autoimmune disease. HLA typing remains a research tool at this time, as does evaluation of humoral and cell-mediated immunity.

Glucocorticosteroids and oral medicine

The article deals with the use of glucocorticosteroids in the treatment of the oral manifestations of Systemic Lupus Erythematosus (SLE), Discoid Lupus Erythematosus (DLE), Rheumatoid Arthritis (RA) in the temporomandibular joint, Pemphigus Vulgaris, Pemphigoid, Erythema Multiforme Exudativum (EME), Lichen Planus (LP), and Recurrent Aphthous Ulcerations (RAU). The benefit from steroids is discussed on the basis of current knowledge of etiology and pathogenesis of the various disorders. All of them are characterized by inflammation which appears secondary to a hypersensitivity reaction against autocomponents. Glucocorticoids do not interfere with the primary disease mechanisms. But it is concluded from the literature, that because of anti-inflammatory and immunosuppressive effects of the hormones, it seems reasonable to profit from steroids as palliatives in acute phases of the diseases and/or as long-term suppressors of the general host defense.

Quantitative and qualitative impairment of immunoregulatory cells in the circulation of rheumatoid arthritic patients

T cells bearing receptors for the Fc portion of IgM or IgG, TM or TG cells respectively, in the peripheral blood of RA and OA patients were found significantly less often when compared with TM and TG cells in the peripheral blood of normal donors. Using culture combinations of TM, TG and B cells, we were able to demonstrate that the B cells in the peripheral blood of RA patients were constantly of low functional competence and the TMcells varied between highly competent and low competent. RATG cells in general suppressed normal B-lymphoblast differentiation.

In vitro immunoglobulin production by mononuclear cells in rheumatoid arthritis

Since patients with rheumatoid arthritis (RA) exhibit serum hypergammaglobulinemia and autoantibody (rheumatoid factor) production, we compared elaboration and control of in vitro RA mononuclear cell (MNC), Ig assayed by enzyme-linked immunoassays or by hemolytic plaque formation, in 37 RA patients and 17 normal subjects. We found (1) RA spontaneous plaque-forming cells were significantly reduced (RA 344 vs normal 627 PFC/10(6) MNC, P less than 0.002); (2) RA spontaneous IgG and IgM (but not IgA) elaboration was significantly diminished (IgG RA 339, normal 776; IgM RA 255, normal 869 ng/ml, P less than 0.001; IgA RA 87, normal 124); (3) RA stimulated IgG and IgM production (but not IgA) was also decreased (IgG RA 2434, normal 3862, P less than 0.06; IgM RA, 1676, normal 3323, P less than 0.005; IgA RA 1859, normal 2315); (4) reduced RA Ig elaboration was not clearly due to altered numbers of T or non-T cells, age, medications, clinical features of disease, or response kinetics; (5) relative improvement of RA in vitro IgG, but not usually IgM, secretion followed removal of adherent cells, addition of indomethacin or addition of mitomycin C-treated T cells; (6) MNC from synovial fluids, but not bone marrows, exhibited spontaneous Ig production in excess of stimulated synovial fluid cellular or peripheral blood Ig elaboration. These observations indicate selective impairment of peripheral blood MNC IgG and, particularly, IgM secretion in RA. This defect appears to reflect accessory cell influences which differ from normal as well as the sequestration of primed or activated cells in the synovial fluid.

Effects of nonsteroidal antiinflammatory drugs on the immune network

The immune system is extremely complex. It comprises many different types of cells and their products. In patients with rheumatic diseases the immune system is activated and has disturbed regulation. It is also believed that immune reactions are involved in the pathogenesis of these disorders. Nonsteroidal antiinflammatory drugs (NSAID) have therapeutic effects on rheumatic diseases. These effects can all be explained by inhibition of prostaglandin production locally in the diseased joints, leading to reduced inflammation. Little or no effects on the number of circulating lymphocyte subpopulations or on peripheral blood mononuclear cell immune reactions can be seen after treatment of patients with rheumatoid arthritis (RA) with NSAID. The possibility, however, exists that immune reactions locally in the diseased joints are modulated by NSAID secondary to reduced prostaglandin production.

Biphasic changes of the immunological reactivity in the course of experimental lectin-induced arthritis of rabbits

A single injection of Lens culinaris lectin (LcL) into the knee joint cavity of non-sensitized rabbits produces an arthritis with an acute and chronic phase, lasting up to one year. The persistence of the lectin in the joint, related to the strong binding affinity of lectins to glycoproteins of connective tissue structures, and the presence of specific antibodies against LcL in the serum after the intra-articular injection make this model comparable to the antigen-induced arthritis. But in our system these conditions are further modified or amplified by the mitogenic activity of LcL itself. The cell-mediated immunity, studied by mitogenic stimulation of peripheral blood lymphocytes, is characterized by a biphasic change in the course of this experimental arthritis. Hyperresponsiveness to stimulation with LcL and Concanavalin A (Con A), decreased Con A-induced suppressor cell activity, and stimulatory serum factors could be detected in the early phase of inflammation. The late phase of arthritis (8 months after the induction) was characterized by hyporesponsiveness to mitogenic stimulation, normal suppressor cell activity and inhibitory serum factors. In spite of the differences of this experimental arthritis to the human rheumatoid arthritis, concerning mainly the initiation and the lack of systemic manifestation, there are surprising similarities between both, not only in the histopathological feature and the chronicity but also in the cell-mediated immune reactions. Therefore, similar pathogenetic mechanisms for the chronic phase can be suggested.

Synthesis of IgM, IgG and IgA in rheumatoid arthritis

We studied the production of immunoglobulins by lymphocytes separated from the blood of 15 rheumatoid arthritis (RA) patients, of 12 patients suffering from other connective tissue diseases (CTD), and of 18 healthy controls. The production of IgM, IgG and IgA in pokeweed-mitogen-stimulated cultures was measured by counting the number of plaque-forming cells (PFC) and by determining the concentration of secreted immunoglobulins by means of an enzyme immunoassay. Synthesis of immunoglobulins, particularly IgM and IgG, was lower than in other CTD patients or controls. The IgM response of RA patients was 20% and 29% (PFC and Ig concentrations) that of the controls. The respective figures for IgG were 33% and 53% and for IgA 61% and 72%.

Epstein-Barr virus-specific cytotoxic T cell responses in rheumatoid arthritis patients

The level of Epstein-Barr (EB) virus-specific cytotoxic T cell responsiveness was measured in 21 patients with active, progressive rheumatoid arthritis (RA). A significant number (8 out of 20) of EB virus sero-positive patients showed a markedly impaired responsiveness when compared with a control group of healthy individuals. Serological responses of the RA patients to EB virus antigens were not significantly different from the control group. The defect in EB virus-specific cellular immunity shown by these results is of interest in the light of previous evidence of an alteration in the virus-host balance in RA patients.

B-lymphocyte subpopulation which forms rosettes with mouse erythrocytes increased in rheumatoid arthritis

We studied the peripheral blood lymphocytes of 22 patients with rheumatoid arthritis (RA) for the presence of a subpopulation of cells which form rosettes with mouse erythrocytes. In normal subjects these cells have been characterised as immature B cells which are non-responsive to pokeweed mitogen. The mean percentage of mouse rosette-forming cells (MRFC) in the rheumatoid group was 13 +/- 10(mean +/- 2 SD), a significantly higher value than the control mean of 5% +/- 4% (P less than 0.001). The T- and B-cell percentages in the rheumatoid patients were normal. The ratio of MRFC: B cells derived from these results was 3:4 in RA and 1:4 in normal subjects. Pre-incubation of rheumatoid peripheral blood lymphocytes at 4 degrees C gave higher values of MRFC (19% +/- 10%) than pre-incubation at 37 degrees C (13% +/- 10%, P less than 0.02), but no such temperature effect was found in the control group. There was no correlation between MRFC and rheumatoid disease activity or the patients' drug regimens. We conclude that the threefold increase in mean MRFC in patients with rheumatoid arthritis indicates an abnormality in the circulating B-cell pool.

Concanavalin-A-activated suppressor cells in patients with juvenile rheumatoid arthritis

Concanavalin-A-induced suppressor cell activity was investigated in 63 patients with a definite diagnosis of juvenile rheumatoid arthritis. Peripheral blood lymphoid cells from these patients did not have the same ability as cells from normal individuals to suppress the proliferative response of autologous cells, responding to phytohaemaglutinin, Candida albicans antigen, or allogeneic cells. No correlation was found between suppressor activity, disease activity, or number of joints involved. Nor was there any significant association between decreased suppressor cell activity and HLA-A, -B, -C, -D antigens, although there was a tendency towards association between decreased suppressor cell activity and HLA-B27.

Con A induced suppressor test: an evaluation of the experimental conditions

The suppressor activity measured by the Con A mixed lymphocyte culture assay exhibited a pronounced dependence on the technical performance as well as a marked inter-individual variation. The activity exerted by the induced suppressor cells depended on the Con A concentration in the induction phase, and on the mitotic activity in the responder system. The patterns of suppressor activities obtained in an allogeneic and an autologous suppressor test system were identical. When calculating the suppressor activity it is suggested, that one uses the total activities of the test system, without any reduction corresponding to the activity of the mixed lymphocyte culture. It is suggested that the suppressor activity is expressed by a "suppressor profile" to make the results more applicable and the interpretation of different works meaningful.

Autologous mixed lymphocyte reactions in patients with rheumatoid arthritis and juvenile rheumatoid arthritis: both non-T cells and in-vivo-activated T cells can act as stimulator cells

The lymphocyte responses in autologous mixed lymphocyte reactions (AMLR) between irradiated non-T and T lymphocytes from the peripheral blood (PB) of rheumatoid arthritis (RA) and juvenile RA (JRA) patients were decreased compared with the AMLR responses of normal PB lymphocytes. Normal AMLR responses were seen in synovial tissue and the synovial fluid lymphocytes from RA and JRA patients. The lymphocyte responses were also decreased in AMLR between irradiated non-T cells from peripheral blood and T cells from synovial tissue (ST) in RA patients and between irradiated non-T from PB and synovial fluid (SF) T cells in JRA patients. However, when irradiated non-T cells from ST of RA patients or from SF of JRA patients were mixed with autologous PB T lymphocytes, increased lymphocyte responses were observed. SF T lymphocytes and ST T cells were also shown to stimulate autologous PB T lymphocytes.

Detection of T-lymphocyte subpopulation in the peripheral blood and the synovium of patients with rheumatoid arthritis and juvenile rheumatoid arthritis using monoclonal antibodies

Monoclonal antibodies with specificities for various human T-cell antigens were used in direct immunofluorescence to quantify the proportions of T lymphocytes with suppressor/cytotoxic-cell markers and with helper/inducer-cell markers and of T lymphocytes with HLA-DR antigens. Normal percentages of lymphocytes with suppressor/cytotoxic-cell markers were detected in the peripheral blood synovial fluid and synovial tissue lymphocytes from patients with juvenile rheumatoid arthritis (JRA) and rheumatoid arthritis (RA), respectively. Normal percentages of T lymphocytes with helper/inducer-cell markers were seen in the peripheral blood of RA and JRA patients and in the synovial tissues of RA patients. Slightly decreased percentages of cells with the helper/inducer-cell marker were detected in the synovial fluids of JRA patients. The proportions of HLA-DR-positive T lymphocytes were highly increased in the synovial fluid and synovial tissue, whereas the numbers of these cells in the peripheral blood were normal. No significant differences in T gamma cells were detected between peripheral blood, synovial fluid and synovial tissue of JRA patients or between peripheral blood and synovial tissue of RA patients.

Concanavalin A induces suppressor cell activity in both T gamma and T non-gamma cells: most of the suppressor cells do not carry HLA-DR antigens

Concanavalin A (Con A) stimulation of T lymphocytes for 48 h induced a dose-dependent increase in the percentage of T gamma cells, and proliferation of these cells was dependent on pre-existing T gamma cells. Con A stimulation also induced a dose-dependent increase in suppressor cell activity as measured in a Con A/mixed lymphocyte culture assay. Removal of T gamma cells before stimulation with Con A did not influence suppressor cell activity, whereas depletion of T gamma cells after Con A stimulation significantly reduced the suppression. Treatment of T lymphocytes with monoclonal anti-HLA-DR antibodies and complement significantly increased the percentage of T gamma cells and also increased the suppressor cell activity, both when the cells were treated before and when they were treated after Con A stimulation. Similarly, increased suppressor cell activity was also seen when T mu cells were removed. The results indicate that Con-A-induced suppressor cells are recruited from both T gamma and T non-gamma cells and also suggest that most of the Con-A-induced suppressor cell activity is exerted by HLA-DR-negative cells.

Defective EBV-specific suppressor T-cell function in rheumatoid arthritis

Several lines of evidence, including high antibody titers to Epstein-Barr virus (EBV)-associated antigens and rapid transformation of B cells into lymphoblastoid cells lines, suggest an association between EBV and rheumatoid arthritis. When lymphocytes from normal immune donors were infected with EBV in culture, they produced an exponentially increasing number of immunoglobulin-secreting cells for eight to 10 days. Thereafter, there was a marked late suppression of their response, mediated by immunoregulatory T cells; by 12 days in culture, this suppression averaged 90 per cent. Lymphocytes from 20 EBV-immune patients with rheumatoid arthritis also responded with increasing production of immunoglobulin-secreting cells, but the late suppression expected in immune donors was absent. Tests of several other T-cell functions in these patients gave normal results, suggesting a more restricted defect in suppressor-T cell function relating specifically to EBV. Since EBV persists in host B cells and thus represents a potential stimulus for immunoglobulin production, this persistence, along with a specific regulatory T-cell defect, may contribute to many of the immune abnormalities underlying rheumatoid arthritis.