Relationship between HLA-DR-expressing cells and T lymphocytes of different subsets in rheumatoid synovial tissue

Presence of human 65 kD heat shock protein (hsp) in inflamed joints and subcutaneous nodules of RA patients

Monoclonal antibodies to the human homologue of the bacterial 65 kD heat shock protein (hsp) were used to investigate the tissue distribution of endogenous hsp 65 in normal versus rheumatoid synovial tissue, in subcutaneous nodules of patients with rheumatoid arthritis (RA) and in several instances of non-rheumatoid inflammation. A strong reactivity of the anti-hsp antibody was found in the cartilage-pannus junction in rheumatoid joints and in rheumatoid nodules, but not in normal joints or in normal or inflamed kidney or liver (irreversible graft rejection, chronic glomerulonephritis or primary biliary cirrhosis). The findings provide a new hypothetical explanation for a role of T cells reactive with the 65 kD hsp in the generation of both articular and extra-articular lesions in chronic rheumatoid arthritis.

Recognition of self class II major histocompatibility complex antigens by CD8+ T cell clones derived from rheumatoid arthritis synovial membrane

T cells from rheumatoid synovium have been expanded in vitro as lines and clones using autologous Epstein-Barr virus-transformed stimulator cells. Both lines and clones recognized autologous class II MHC antigens in the absence of defined exogenous antigens i.e. the equivalent of the autologous mixed lymphocyte response. Surprisingly, despite their MHC specificity, several clones expressed CD8 rather than CD4, but were not cytotoxic. The function of CD8+ T cells within synovium has not previously been defined; in view of their unusual phenotype, they may exert an immuno-modulating role upon the inflammatory response within the joint, by responding to the high density of class II MHC antigens expressed in the rheumatoid synovium.

Elevated soluble CD8 in the synovial fluid from patients with rheumatoid arthritis

Suppressor/cytotoxic T cells express the surface marker CD8, which can be measured in a soluble form in culture supernatants of activated human lymphocytes. Using a sandwich immunoassay, we assessed the levels of soluble CD8 (sCD8) in serum from patients with rheumatoid arthritis (RA; n = 82), patients with degenerative joint disease (DJD; n = 40), and healthy controls. There were no differences in serum sCD8 levels among these groups. In contrast, the levels of soluble CD8 in the synovial fluid (SF) from patients with RA (n = 53) were significantly increased compared with the levels in 23 samples from patients with DJD (821 +/- 110 U/ml versus 213 +/- 13 U/ml, p less than 0.001). Synovial fluid sCD8 levels in the RA group were strikingly elevated, to a maximum value of 5,026 U/ml. In the majority of RA SF specimens (39 of 53), the values were significantly higher in the SF than the serum. Although the RA group had higher values of sCD8, such values were not significantly correlated with measured laboratory or clinical parameters. Current clinical and laboratory methods of evaluating patients may not be adequate in dealing with the complexity and heterogeneity of RA. Soluble CD8 values may be useful in further grouping patients with this disease.

Soluble interleukin-2 receptor: elevated levels in serum and synovial fluid of patients with rheumatoid arthritis

Soluble interleukin-2 receptor (sIL-2R) levels were quantitated in the serum and synovial fluid (SF) of patients with rheumatoid arthritis (RA) and degenerative joint disease (DJD). A sandwich immunoassay, employing two monoclonal antibodies against distinct epitopes on the IL-2R, was utilized for measurement. We found a striking elevation of sIL-2R in RA SF as compared with DJD SF (RA, 1319 +/- 135; DJD, 416 +/- 59; p less than 0.001). RA serum sIL-2R levels were also significantly elevated over DJD levels. There was no interaction between rheumatoid factor (RF) and sIL-2R. RA patients with elevated sIL-2R levels had significantly longer disease duration, higher c-reactive protein (CRP) levels in serum and SF, and higher RF levels in serum and SF. The groups were similar in regard to other laboratory variables. The presence of elevated levels of sIL-2R in RA serum and SF confirms the presence of a heightened immune reactivity and in vivo activation of lymphocytes in RA.

Collagen-induced arthritis in mice. VI. Synovial cells from collagen arthritic mice activate autologous lymphocytes in vitro

Synovial cells were extracted from normal and collagen-arthritic mice and investigated for lymphocyte-activating properties. In mixed cell culture, irradiated fibroblast-like synovial cells from DBA/1 LacJ arthritic mice stimulated a strong proliferative response in spleen cells from syngeneic normal mice, but not in cells from allogeneic DBA/2. B10.RIII, or BALB/c mice. This novel stimulus occurred in the absence of detectable Class II MHC antigen expression on the fibroblast-like synovial cell surface or increased autologous mixed lymphocyte reactions between DBA/1 LacJ spleen and lymph node cells. Irradiated synovial cells were also unable to present type II collagen to a collagen-specific T cell line and to stimulate proliferation. Addition of interferon-gamma or interleukin-1 failed to induce detectable surface Ia on the synovial fibroblasts or induce the capacity for antigen presentation in these cells.

Localisation of lysozyme mRNA in rheumatoid synovial membrane by in situ hybridisation

Type A synovial lining cells have been shown to contain lysozyme in their lysosomes. This might be phagocytosed because synovial fluid contains lysozyme originating from tissue macrophages and articular cartilage but in arthritides, in particular, from neutrophils. In situ hybridisation with 35S labelled cDNA was used to detect mRNA for lysozyme over synovial lining in patients with rheumatoid arthritis. No hybridisation was found with lactoferrin cDNA, which was used as a negative control. Computer search against the EMBL gene bank (release 14) did not show any significant cross hybridisation to a known sequence. In cytological specimens 35S-cDNA:mRNA hybrids were observed in positive but not in negative control cells. The presence of lysozyme and its mRNA suggests that type A synovial lining cells are of mononuclear phagocyte lineage.

Changes in lymphocyte infiltration of the synovial membrane and the clinical course of rheumatoid arthritis

Multiple samples of synovial membrane were obtained by needle biopsy from 24 patients with rheumatoid arthritis (RA) before, and 1 year after, standard antirheumatic drug therapy was given. Changes in the immunohistologic features of the synovial membrane (read blindly) were compared with the clinical course of RA in each patient. A composite clinical index of disease activity (IDA) and spontaneous in vitro synthesis of IgM rheumatoid factor (IgM-RF) by blood mononuclear cells were also measured before and after treatment. In 16 patients (group A), the IDA indicated 26-69% improvement, and the values for spontaneous IgM-RF decreased substantially. In 8 patients (group B), the IDA indicated deterioration or no improvement, and the values for spontaneous IgM-RF were unchanged. In group A patients, the intensity of the T cell infiltrate decreased from a mean score of 1.3 to a mean score of 0.8 (P = 0.025). The ratio of T helper cells to T suppressor/cytotoxic cells was greater than or equal to 2:1 in 90% of group A patients before treatment, compared with 20% of these patients after treatment (P = 0.016), and the number of biopsy samples that contained identifiable B cells decreased from 36% before treatment to 7% after treatment. In group B patients, there were no changes in the intensity of T cell infiltration, the ratio of T helper cells to T suppressor/cytotoxic cells, or the number of biopsy samples with identifiable B cells.

Macrophages and dendritic cells during the early stages of antigen-induced arthritis in rats: immunohistochemical analysis of cryostat sections of the whole knee joint

The appearance of different macrophage subpopulations, Ia-positive antigen-presenting dendritic cells and of T and B lymphocytes was studied in early phases of antigen-induced arthritis in rat knee joints. Cryostat sections of whole knee joints were analysed with immunohistochemical techniques using monoclonal antibodies against rat macrophages, Ia-antigen, and lymphocyte subpopulations. The results showed that in the early phases of the development of arthritis, the synovium was already infiltrated by many monocytes, young macrophages, granulocytes, perivascular Ia-positive non-lymphoid cells, some mature tissue macrophages, and only few T lymphocytes. In later phases not only monocytes, young macrophages and Ia-positive cells became more prominent but also the more mature ED2 positive macrophages and the ED3 positive macrophages that are normally confined to lymphoid organs became increasingly important. The T-cell population increased to some extent in later phases of arthritis induction, possibly induced by clustering with the Ia-positive cells.

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.

Reactions in rat gluteal muscle to titanium implants

A new approach to the analysis of tissue-implant interaction is presented using rat gluteal muscle as implantation site and using monoclonal antibodies to identify and quantify cells around the implant. The method can be used for comparative studies on biocompatibility. In this methodological investigation, pure titanium (Ti) was studied, revealing an initial response of macrophages, followed by the formation of a fibrous membrane, in which, even at 50 and 70 d, la-expressing cells and suppressor T-lymphocytes were present.

New perspectives on the pathogenesis of rheumatoid arthritis

In the pathogenesis of rheumatoid arthritis, locally produced antibodies complex with an inciting antigen, yet to be identified, within the joint and activate the complement system, resulting in articular inflammation mediated primarily by polymorphonuclear leukocytes and their products. Chronic inflammatory cells then produce soluble factors that induce both tissue destruction and inflammation. A major issue is how and why apparently normal immune responses in the acute stage progress to chronic inflammation in subsequent months to years. Although it is often assumed that the initial etiologic agent, persisting in the joint or at an extra-articular site, is responsible for continued synovitis, this need not be the case. It is possible that once the inciting agent is cleared from the joint through a normal immune response, the presence of activated cells rich in surface class II histocompatibility (Ia) antigens could, under the influence of multiple genetic or environmental factors, become the target of autoimmune attack. Alternatively, the process might result from the interactions of synovial lining cells and their products with T cells assuming a secondary role. Further research into the relative contributions of soluble products, T helper and suppressor subsets, synoviocytes, and antigen determine which model is correct.

HLA DR and DQ distribution in normal human ocular structures

HLA DR and DQ distribution was investigated in normal human ocular tissues, together with class I antigens and immunocompetent cell subsets, by immunofluorescence and immunoperoxidase procedures. In the anterior segment, our findings, consistent with those of previous reports, showed the wide distribution of class I antigens, specially in the corneal epithelium, while class II antigens were restricted to very rare cells scattered in the conjunctiva, the peripheral cornea and the stroma of the ciliary processes. Some non pigmented epithelial cells of the ciliary processes were HLA DR and DQ positive. In the posterior segment, class I antigens were abundantly represented in the choroid and the retinal layers. Few HLA DR and DQ positive cells were seen in the choroid, similar to those found in the anterior segment. Normal RPE did not react with any monoclonal antibody, but numerous cells located in the retina were strongly HLA DR and DQ positive, all around the blood vessels, and not at the sites of endothelial cells. The characterization of those cells, which could be hypothetized as pericytes needs further studies but suggests close relationships between neuroretina and the immune system. This study may provide insight in the implication of the immune system in many poorly understood ocular diseases.

Elevated soluble interleukin-2 receptor levels in the sera and synovial fluids of patients with rheumatoid arthritis

In a previous study, we used an enzyme-linked immunosorbent assay to measure soluble human interleukin-2 receptors (IL-2R), and found that when activated lymphocytes produce cell-associated IL-2R, they also release a soluble form of IL-2R into culture supernatants in vitro. Soluble IL-2R have also been detected circulating in vivo at low levels in the serum of healthy individuals, and at abnormal levels in a variety of diseases, particularly those where immune dysfunction is thought to play an important role. We therefore evaluated serum IL-2R levels in 77 patients with rheumatoid arthritis (RA), and compared them with levels in 46 age-matched healthy controls. Nineteen additional RA patients with concurrently obtained sera and synovial fluid (SF) samples were compared with 14 patients with osteoarthritis of the knee or hip. The serum IL-2R levels were significantly elevated in RA patients, compared with the control groups (P less than 0.0001). Serum IL-2R levels in the RA patients did not correlate with disease activity as determined by a variety of clinical and laboratory parameters. RA SF IL-2R levels were significantly higher than corresponding RA serum IL-2R levels (P = 0.0001). No such difference was noted in the osteoarthritis group, where serum and SF IL-2R levels were comparable with serum levels in healthy controls. These findings support the hypothesis that in vivo lymphocyte activation plays an important role in RA; moreover, soluble IL-2R measurement in serum and SF may be a very useful way to identify patients at risk for, or manifesting, a chronic immune-mediated inflammatory arthropathy.

Mononuclear cells recovered from inflammatory synovial membrane using fine-needle biopsy

A simple technique for fine-needle aspiration biopsy from the synovial membrane of arthritis knee joints preceded by lavage of the joint cavity is described. The procedure was atraumatic, well accepted, and could be performed on outpatients. Cells originating from the synovial membrane were obtained in 12 of 17 knees using a 1.2-mm cannula. The yield was 6.0 x 10(3) to 135 x 10(3) mononuclear cells. The cell populations could be expanded by stimulation with antigen and mitogen. The described fine-needle biopsy technique is of value when repeated sampling of synovial membrane cell populations is desired.

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).

Dissection of the mechanisms of immune injury in rheumatoid arthritis, using total lymphoid irradiation

Eleven patients with intractable rheumatoid arthritis were treated with total lymphoid irradiation. After radiotherapy, there was a marked decrease in the number and function of peripheral blood helper/inducer (Leu-3+) T lymphocytes, in the spontaneous secretion of interleukin-1 by synovial biopsy specimens, and in the activity of the joint disease. In contrast, levels of IgM, IgA, and IgG rheumatoid factors and C3 concentrations in blood and synovial fluid samples did not change significantly after therapy with total lymphoid irradiation.

Future trends in the treatment of rheumatoid arthritis in the light of current etiopathogenetic theories

The current treatment of rheumatoid arthritis is based on the use of synthetic chemical compounds, the mechanism and action of which have been more or less unknown. Usually this therapeutic effectiveness was discovered accidentally. Often the initial use of such compounds was motivated on the basis of generally diffuse ideas about the eventual pathogenesis of rheumatoid arthritis. The main site of action of most of these drugs has recently been elucidated. Depending on their multiple sites of action the polypharmacy frequency relied upon at present seems also to be theoretically motivated. Many new possibilities for treatment which have appeared recently have resulted from the amission of page limitation. These include various thymic (46), steroid and other hormones (67) and various vehicles or new modes of application, e.g. percutaneous, for directing the effects of drugs selectively to the target tissue, organ and cells. The use of specific T cell clones in therapy (68) has been only briefly dealt with in this article, and the development of operative techniques, endoprosthesis technology and orthopedic devices have not been dealth with at all. Chemical synovectomies with 165Dy-FHMA and other agents (69) will be developed further etc. This overview mainly deals with future trends in the treatment of rheumatoid arthritis based on advances made in the evaluation of the etiopathogenesis. Due to advances in basic sciences and medicine, the pathogenetic mechanisms effective in rheumatoid arthritis are better known today than ever before. The same progress in science has for the first time in history provided us with a potential means of producing bioactive mediators and reagents in sufficient amounts to enable their use also for therapeutic trials and treatment. In addition to the need to develop better methods of treatment for the patients crippled by this chronic disease, studies on the pathogenesis will also be of great benefit to our ideas about exactly what is involved in the complex process clinically known as rheumatoid arthritis.

Interactions between the immune system and connective tissue in arthritis: aspects on T-cell activation

The synovial inflammation in rheumatoid arthritis can both serve as a model for the study of chronic inflammation in general and be analyzed with the goal to understand which features that distinguish RA from other chronic inflammatory diseases. In this paper we discuss both these problems with the emphasis on mechanisms of T cell activation and how activation of T cells against structures associated with the cartilage may contribute to the perpetuation of RA by means of triggering rheumatoid factor production. We also present some original data concerning phenotypes of in vivo activated synovial T cells, demonstrating high levels of HLA-DR expression, low levels of CD45+/Leu3a+ T "suppressor/inducer" cells and varying numbers of Leu 15+/Leu2a+ "suppressor" T cells. The observed phenotypic pattern is compatible with the occurrence of a normal but perpetuated immune response to a persistant antigen "X" in the arthritic joint.

T cell subsets and expression of immunological activation markers in the arterial walls of patients with giant cell arteritis

Immunohistochemical features of infiltrating mononuclear cells (MNC) and resident cells were studied in the temporal artery biopsy specimens of 13 patients with histological verified giant cell arteritis (GCA) and in six biopsy specimens from patients with GCA with negative histological findings. Eight temporal artery biopsy specimens from seven patients with unrelated diseases served as controls. In all patients with GCA proved by biopsy an infiltration of T lymphocytes in the arterial wall was observed, most being of the helper/inducer subset. No B lymphocytes, or very few, were seen. Lymphocytes in 10 out of the 13 positive biopsy specimens displayed staining for the class II major histocompatibility complex (MHC) antigen HLA-DR, whereas this was found in only two of eight controls. A minor number of the infiltrating T lymphocytes from seven out of 13 patients with GCA proved by biopsy stained for transferrin receptors, and in six out of the 13 cases they reacted with anti-interleukin 2 receptor antibody. In the arterial wall from all patients with histologically verified GCA we also found an increased number of macrophages, many of them expressing HLA-DR antigens and transferrin receptors. The immunohistochemical pattern of cell phenotypes found in the arterial wall of patients with GCA suggests that the infiltrating T cells are immunologically activated. This finding supports the hypothesis of a predominantly cellular immunological pathogenesis of giant cell arteritis.

Macrophages and dendritic cells in antigen-induced arthritis. An immunohistochemical study using cryostat sections of the whole knee joint of rat

Two non-lymphoid cell types play an important role in the pathogenesis of arthritis, i.e. the 'classical' macrophage and the antigen-presenting dendritic cell. In the present study, the roles of both cell types are studied in antigen-induced arthritis of the rat knee joint. Cryostat sections of whole, unfixed, undecalcified knee joints were used for immunohistochemical staining of non-lymphoid cells and lymphocyte subsets. For the demonstration of the different types of non-lymphoid cells, monoclonal antibodies against rat macrophages (ED1, ED2, and ED3) and against Ia antigen were used with an immunoperoxidase method. The results show in an overall view of the arthritic joint the different sites of action of the classical macrophages on the one hand and the Ia-positive dendritic cells on the other. Classical macrophages were mainly found in the superficial layers of the synovium bordering joint space and articular cartilage. Dendritic cells and T cells of the helper phenotype were mainly found in clusters surrounding small blood vessels within the synovium. These clusters express the immunological background of the antigen-induced arthritis and may well be responsible for the continuation of the arthritic process.

Arthroscopic and immunohistologic characterization of knee joint synovitis in osteoarthritis

We studied 10 patients who had arthritis of the knee joint, but no other signs of rheumatic disease. The clinical diagnosis of osteoarthritis was corroborated by arthroscopic evidence of characteristic cartilage degeneration. Signs of inflammation were confined to areas of the synovial membrane that lay near the cartilage; thus, the major part of the joint cavity was not affected. The intensity of the synovial inflammation varied within the areas involved, but was always most pronounced in regions rimming the cartilage. Biopsy samples selected from regions of intensely inflamed synovium contained foci of T lymphocytes, which were bordered by immunoglobulin-carrying B lymphocytes and plasma cells, as well as strongly HLA-DR positive dendritic-like cells adjoined to alpha Leu-3a+ T helper lymphocytes. In tissue samples taken from macroscopically noninflamed areas, only a few infiltrating lymphocytes were seen. Thus, the inflammatory synovial changes found in osteoarthritis appear to be anatomically restricted and of varied intensity but, when present, are microscopically indistinguishable from the changes that have been previously described as indicative of rheumatoid arthritis.

Dendritic cells in the pathogenesis of rheumatoid arthritis

The cause of rheumatoid arthritis is unknown. It appears that abnormal or overstimulated cell-mediated immune mechanisms are operating. Dendritic cells, with their potent antigen presenting and immunostimulatory properties, have been found in increased numbers of rheumatoid synovial fluids and membranes. It is postulated that these cells play a key role in inducing and perpetuating the immune response with subsequent synovial proliferation and joint destruction.

Evidence of an activated T-cell system with augmented turnover of interleukin 2 in rheumatoid arthritis. Stimulation of human T lymphocytes by dendritic cells as a model for rheumatoid T-cell activation

The stage of activation of synovial inflammatory T cells was studied in rheumatoid arthritis and compared with that of normal T cells stimulated in vitro by dendritic cells. Increased numbers of rheumatoid inflammatory T cells expressed activation antigens such as HLA-DR, interleukin 2 receptors (Tac), and transferrin receptors. These T cells also had high spontaneous proliferation. Peripheral blood T cells stimulated by autologous dendritic cells showed a similar expression of activation antigens and had high proliferation. Resting T cells and T cells cocultured with monocytes expressed much less activation markers. Exogenous interleukin 2 significantly increased the proliferation of the various T cells. All responses were inhibited by an antibody which blocks the interleukin 2 receptor. Supernatants from mitogen-stimulated rheumatoid inflammatory mononuclear cells and mitogen-stimulated T cells preactivated by dendritic cells usually contained less interleukin 2 than supernatants from mitogen-stimulated normal T cells. Furthermore, the various in vivo and in vitro-activated Tac-positive T cells, in contrast to nonactivated Tac-negative T cells from peripheral blood of patients and controls, significantly absorbed interleukin 2. The results indicate a turnover of interleukin 2 in rheumatoid inflammatory T cells comparable to that of T cells activated by dendritic cells.

Inhibitor of interleukin-2 in rheumatoid synovial fluid

Although large numbers of T cells infiltrate the synovium of patients with rheumatoid arthritis (RA), the responses of these cells, as present in the blood and synovial fluid (SF), to exogenous interleukin-2 (IL-2) and their production of IL-2 are diminished. To investigate this functional defect, RA SF were examined for the presence of inhibitors of IL-1 and IL-2. A factor was found which inhibited the IL-2-induced proliferation of mitogen-stimulated human T cells and the IL-1-induced proliferation of C3H/Hej mouse thymocytes, but not IL-1-induced fibroblast proliferation. On AcA 54 Ultrogel filtration, the inhibitory activity resided in a fraction with an apparent molecular weight of greater than 70 kd and a major pI of 6.8. The inhibitory effect of RA SF on lymphocyte proliferation was partially corrected with IL-2, but not with IL-1. In the presence of RA SF, normal lymphocytes showed not only a decreased response to exogenous IL-2, but also a decreased production of IL-2. The presence of an inhibitor of IL-2 in RA SF could contribute to the IL-2-related T cell defects observed in RA.

Mast cell numbers in rheumatoid synovial tissues. Correlations with quantitative measures of lymphocytic infiltration and modulation by antiinflammatory therapy

Synovial biopsy specimens from 20 patients with rheumatoid arthritis were subjected to quantitative analysis for several parameters of inflammation and for enumeration of synovial tissue mast cells. Strong positive correlations were found between numbers of mast cells per cubic millimeter of synovial tissue and the following synovial tissue parameters: inflammatory index (a quantification of lymphocytic infiltration), Leu-3a grade (T helper/inducer lymphocytes), Leu-1 grade (T lymphocyte), and plasma cell grade. A strong negative correlation was found between the synovial mast cell count and the extent of sublining layer fibrin deposition. Correlations between synovial mast cell count and Leu-2a grade, ratio of Leu-3a grade:Leu-2a grade, OKM1 grade, HLA-DR grade, and lining layer thickness grade did not reach statistical significance. In addition, we obtained synovial specimens from 6 of the patients both before and after long-term therapy with oral methotrexate and from 3 of the patients before, and 1 week after, an intraarticular injection of steroid. The 3 patients who had an intraarticular steroid injection showed a 67-96% decrease in the number of synovial tissue mast cells; there was no significant change in the number of synovial mast cells in the tissues of the 6 patients who received oral methotrexate. These observations are the first documentation of a quantitative relationship between the number of mast cells and the number and phenotypic profile of infiltrating lymphocytes in an inflamed tissue, which in this case, is human synovium. Our findings suggest that mast cells are involved in the pathologic interactions in rheumatoid arthritis and might play a role in the early phases of exacerbations of disease activity.

Phenotypes of T lymphocytes from peripheral blood and synovial fluid of patients with rheumatoid arthritis and juvenile rheumatoid arthritis. Evidence in favour of normal helper and suppressor functions of T lymphocytes from patients with juvenile rheumatoid arthritis

Lymphocytes from peripheral blood (PB) and synovial fluid (SF) from 21 patients with rheumatoid arthritis (RA) and 18 patients with juvenile rheumatoid arthritis (JRA) were studied with respect to T cell phenotypes using monoclonal antibodies in a rosette assay. The percentage of HLA-DR positive T cells was counted in PB and SF using indirect immunofluorescence. Suppressor cell activity of T cells from PB and SF was investigated by measuring the immunoglobulin production by pokeweed mitogen (PWM) stimulated B cells mixed with T cells at various ratios. The mean T4/T8 ratio was significantly lower in SF than in PB of both RA and JRA patients (p = 0.0062 and p less than 0.0001 respectively). The mean percentages of HLA-DR positive T cells were elevated in SF compared with PB in both patients groups (p less than 0.03 and p less than 0.04 in RA and JRA patients respectively). Mean suppressor cell activity and helper cell activity of T cells from SF and PB of JRA patients was normal. Thus there seems to be a dichotomy between the number of T8+ cells and suppressor cell function in mononuclear cells from SF of patients with JRA. This indicates that a considerable proportion of the T8+ cells in the SF do not have suppressor functions.

Class II antigens in Hashimoto thyroiditis. II. Expression of HLA-DR on infiltrating mononuclear cells in peripolesis

Surgical specimens from patients with Hashimoto thyroiditis (HT) or colloid goiter (CG) were analyzed using an immunofluorescence double staining technique to characterize the infiltrating mononuclear cells (MNC) and to determine the possible expression of HLA-DR antigens by these cells. In HT the majority of infiltrating MNC were T cells. In the interstitium T cells with helper/inducer phenotype (Leu 3a+) were more abundant than those with suppressor/cytotoxic phenotype (OKT8+) and approximately 10-25% of all T cells expressed HLA-DR. Among the cells in peripolesis [i.e., protruding between thyroid epithelial cells (TEC)] OKT8+ cells were observed more frequently than Leu 3a+ cells, expression of DR antigens being 7 and 12%, respectively. The occurrence of Leu 3a+ cells in peripolesis is in marked contrast to the findings in colloid goiter where the intraepithelial population of MNC is almost exclusively composed of OKT8+ cells. The various ways in which the peripoletic Leu 3a+ cells could contribute to the special pathogenesis of HT are discussed.

Lymphocytes, polymorphonuclear leukocytes, macrophages and platelets in synovium involved by rheumatoid arthritis. A study with monoclonal antibodies

The inflammatory cell infiltrate involving synovial tissues from joints affected by rheumatoid arthritis (RA)++ has been contrasted with that present in synovium removed from joints involved by previous trauma (T) or osteoarthritis (OA). Cell deployment has been mapped by immunohistochemistry using monoclonal antibodies which recognise epitopes characterising T and B cells, polymorphonuclear leukocytes, mononuclear phagocytes and platelets. Mononuclear phagocytes were the most consistent feature of the rheumatoid inflammatory cell exudate and were present, particularly in the synovial layer, in all OA/T samples. The synovial cells lacked the C3b complement receptor, CR1, but expressed CR3, the receptor for C3bi. In rheumatoid synovium, interdigitating cells were difficult to identify but cells of dendritic morphology bore at least one macrophage epitope. T cells far out-numbered B cells and generally lacked the IL-2 receptor which is an indicator of T cell activation. Care is required in the estimation of the T helper/inducer (TH) T suppressor/cytotoxic (Ts) ratio. Polymorphonuclear leukocytes were demonstrated around vessels and near the synovial intimal cell layer suggesting rapid tissue transit. Extravascular platelets were sparse. Follicular dendritic cells were defined by their central location in lymphoid follicles and strong expression of CR1 receptors. HLA-DR expression was widespread except on endothelial cells.

Intralesional T lymphocyte phenotypes and HLA-DR expression in Melkersson-Rosenthal syndrome

An immunohistochemical double-staining technique was used to characterize the infiltrating mononuclear lymphocytes in frozen sections from 3 patients with Melkersson-Rosenthal syndrome. The in situ expression of HLA-DR antigens on different cell types was also investigated. The majority of mononuclear cells could be classified as T-lymphocytes because of their Leu 4 antigen expression. Most of the T-lymphocytes were confined to the helper/inducer lymphocyte subset since they reacted with Leu 3a antibodies. However, big infiltrates of suppressor/cytotoxic lymphocytes with the Leu 2a phenotype were noted in some specimens. These cells were situated between the ducts of the salivary glands. Virtually all mononuclear infiltrating cells carried HLA-DR antigens. HLA-DR expressing keratinocytes were found in the biopsy from one patient. The present study indicates that a local immune response may be important in the pathogenesis of the oro-facial lesions in Melkersson-Rosenthal syndrome.

Reactivity of monoclonal anti-type II collagen antibodies with cartilage and synovial tissue in rheumatoid arthritis and osteoarthritis

Monoclonal antibodies to 3 different epitopes on native type II collagen were used for immunohistochemical analysis of antigenic determinants that are exposed in the cartilage and synovial tissue obtained from patients with rheumatoid arthritis (RA) and osteoarthritis (OA). Two of the monoclonal antibodies reacted with cartilage from both OA and RA joints, but not with that from normal joints. The third monoclonal did not stain any of the cartilage sections. The 2 positive antibodies also reacted with cartilage fragments in the synovial tissue of both RA and OA joints, and in RA pannus tissue, the antibodies showed intracellular staining in many class II transplantation antigen-expressing synovial cells lying close to the damaged cartilage.

Electron microscopic study of HLA-DR and monocyte/macrophage staining cells in the rheumatoid synovial membrane

We examined synovial membrane samples from 6 rheumatoid arthritis (RA) and 3 osteoarthritis patients and from 1 normal subject, by an immunoelectron microscopic technique using anti-HLA-DR (anti-Ia) and anti-monocyte/macrophage (63D3) monoclonal antibodies. In the lining layer, the type A macrophage-like cells were strongly DR+ and 63D3+, whereas the type B fibroblast-like cells were almost completely negative. Lymphocyte-rich areas (containing more than 90% densely packed lymphocytes) showed weak and patchy DR staining of the lymphocytes. In these areas, 3-5% of the cells were macrophage-like cells which were 63D3-, a type of staining compatible with that of the interdigitating cell (IDC). In the plasma cell-containing (transitional) areas, many strongly DR+ macrophage-like cells were observed in close contact with lymphocytes and plasma cells. Ten to twenty percent of these cells were 63D3-, which suggests that they were IDC. Cells with the structural appearance of IDC were most frequently seen in those transitional areas which contained elevated concentrations (50-70%) of lymphocytes. In uninfiltrated interstitial areas, approximately 50% of the cells stained strongly with both anti-DR and 63D3 antibody, indicating that they were cells of monocyte/macrophage lineage, presumably histiocytes. This investigation has demonstrated the presence of the DR antigen in the RA synovial membrane on 1) phagocytic cells of the lining area, 2) lymphocytes and small numbers of IDC-like cells in dense, lymphocyte-rich areas, 3) large numbers of macrophage-like cells, of which some had the morphologic appearance of IDC, in transitional or plasma cell-containing areas, and 4) histiocytic cells in uninfiltrated interstitial areas. The observation of large numbers of DR+ macrophages and IDC-like cells in close contact with lymphocytes and plasma cells in the RA synovial membrane emphasizes their role in an active immune response. The observation of substantial numbers of potentially immunocompetent, DR+ histiocytic cells in uninfiltrated regions of the synovial membrane suggests that such cells may play a role in the progression of the synovial inflammatory reaction.

Interleukin-1 lymphocyte chemotactic activity in rheumatoid arthritis synovial fluid

We examined the role of interleukin-1 (IL-1) in the chemotactic activity of rheumatoid arthritis (RA) synovial fluid (SF). Crude RA SF was found to be chemotactic for B cells and T cells. After AcA 54 gel filtration, the principal peaks of chemotactic activity were found in the 5-kd, 16-kd, and 60-kd fractions. The majority of the chemotactic activity for both the B cells (74-85%) and the T cells (69-78%) was removed from these fractions by treatment with anti-IL-1 antibody. However, in crude SF, approximately 60% of the chemotactic activity for B cells and 40% of that for T cells was removed, indicating the presence of additional chemotactic factors in RA SF. IL-1 activity, measured by the thymocyte proliferation assay, was demonstrated in RA SF AcA 54 Ultrogel fractions after separation from inhibitors of thymocyte proliferation that are present in crude SF. On chromatofocusing of the 16-kd fraction, the principal peaks of both thymocyte proliferation activity and chemotactic activity were present in the same fractions with pI values of 6.8, 5.7, and 5.2, which are characteristic of IL-1. The demonstration of IL-1-associated chemotactic activity in RA SF may reflect the presence in the RA synovial membrane (including both the lining layer and the subsynovial layer) of activated macrophages, interstitial histiocytic cells, and other IL-1-producing cells, such as endothelial cells. These findings suggest that such cells may attract lymphocytes to their environment by secretion of IL-1.

Cell-mediated immunity in rheumatic disease

Rheumatoid arthritis, systemic lupus erythematosus, and systemic sclerosis are the three most common systemic rheumatic diseases in which disordered immune function is thought to play a pathogenetic role. Each disease has different and characteristic abnormalities of the cellular immune system. In rheumatoid arthritis the identified abnormalities of immunoregulation are largely limited to specific antigens: Epstein-Barr virus and collagen. Systemic lupus erythematosus is characterized by exuberant B-cell activity with exaggerated humoral response, a diversity of autoantibodies, non-antigen-specific loss of suppressor cell function, and general suppression of cell-mediated immunity. In systemic sclerosis systemic defects of cellular and humoral immune function are mild, but the release of lymphokines and monokines at sites of inflammatory lesions is thought to be important in the pathogenesis of the disease. Similar immune cell-connetive tissue cell interactions are probably important in the propagation of rheumatoid synovitis. Thus, despite the many shared clinical and serologic features of these diseases as well as the presence of many patients who have clinically overlapping features of more than one of these entities, the immune defects and the immunopathogenesis of these disorders appear to be distinct.

The role of Ia positive T cells in patients with rheumatoid arthritis

In peripheral blood and synovial fluid of patients with rheumatoid arthritis (RA), increased levels of Ia antigen-positive (Ia+) T cells have been demonstrated. Therefore, we examined these Ia+ T cells in vitro to identify their role in the production of rheumatoid factor (RF) and to study the immunologic abnormalities of RA. When Ia+ T cells from peripheral blood of RA patients were added to pokeweed mitogen (PWM)-non-stimulated autologous B cells, the amount of IgM-RF production was 25.8 +/- 6.4 (mean +/- SE) (p less than 0.001) as compared to 16.0 +/- 4.6 ng/ml (mean +/- SE) in the presence of Ia-T cells. When Ia-OKT4+ cell fractions, obtained by excluding Ia+ T cells from OKT4+ cells, were added to B cells, the increase in IgM-RF production was markedly lower than that obtained with the OKT4+ cell fraction. These results indicate that the helper T cells which induce the production of IgM-RF may derive from the Ia+ OKT4+ cell fraction. B cells from rheumatoid synovial fluid produced IgM-RF levels as high as 102.7 +/- 19.2 ng/ml (mean +/- SE) even without stimulation. When T cells from autologous synovial fluid were added, IgM-RF production was not increased. These data suggest that B cells from RA synovial fluid had already been activated. When synovial fluid T cells were added to B cells from autologous peripheral blood, larger amounts of IgM-RF were produced as compared to experiments in which T cells from peripheral blood were added, suggesting that T cells from synovial fluid induced an enhanced IgM-RF production by B cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Subepithelial neuroendocrine cells and carcinoid tumours of the human small intestine and appendix. A comparative immunohistochemical study with regard to serotonin, neuron-specific enolase and S-100 protein reactivity

A comparative immunocytochemical study was performed of subepithelial neuroendocrine cells of the human small intestine and appendix and carcinoid tumours of these sites, using a monoclonal antibody to serotonin and polyclonal antisera against neuron-specific enolase (NSE) and S-100 protein. Subepithelial neuroendocrine cells were easily identified in the lamina propria of the appendix. These cells, which sometimes occurred in aggregates, displayed serotonin and NSE immunoreactivity and were surrounded by S-100 protein immunoreactive cells, presumably of Schwann cell origin. In the appendix scattered cells with corresponding morphological features and immunoreactivity were also observed deep in the submucosa. In addition, subepithelial neuroendocrine cells were sparsely present in the lamina propria of the small intestine, occurring only as single cells in the deeper part of the mucosa below or between the epithelial crypts. Most appendiceal carcinoid tumours (11 of 12 examined cases) were biphasic and consisted of neuroendocrine tumour cells with intermingled S-100 protein immunoreactive cells (Schwann cells) with long cytoplasmic extensions. However, small intestinal (11 cases) and caecal (10 cases) carcinoids lacked S-100 protein immunoreactive cells as an integral component. The results indicate that the appendiceal carcinoids are mostly closely related structurally to the subepithelial neuroendocrine and Schwann cell aggregates of the lamina propria and are thus presumed to be histogenetically related to this cell system, while the histogenesis of small-intestinal and caecal carcinoids remains less clear.

Electron microscopic study of rheumatoid synovial vasculature. Intimate relationship between tall endothelium and lymphoid aggregation

The relationship between (a) "tallness" and (b) cross-sectional area of the endothelial cells (EC) of postcapillary venules (PCV) and capillaries and the cellular composition of adjacent perivascular mononuclear cell infiltrates in rheumatoid (RA) synovial membrane has been examined by electron microscopy. "Tallness" of the EC was measured as the ratio of the height of the EC to its base (H/B). H/B showed a strong positive correlation with the number and percent of perivascular lymphocytes, i.e., the denser the lymphoid aggregation, the taller the EC. In contrast, H/B showed negative correlations with percent perivascular plasma cells, macrophages, and fibroblast(cyte)s. No such correlations were observed with pericapillary infiltrates. A computer-based morphometric technique yielded similar relationships between the cross-sectional area of the EC and the composition of the perivascular infiltrates. These results indicate that the EC of PCV in lymphocyte-rich areas of synovium tend to be tall and to occupy an increased fraction of the cross-sectional area of the vessel. In contrast, in areas rich in macrophages and plasma cells, EC tend to be flat and to occupy a smaller fraction of the cross-sectional area. PCV in uninfiltrated interstitial areas and in normal synovium had flat EC, and capillaries had flat EC regardless of the character of the surrounding infiltrate. Finally, PCV in lymphocyte-rich areas closely resembled those of tonsil in appearance. Our findings indicate that the PCV of the RA synovial membrane from which lymphocytes emigrate to form perivascular lymphoid aggregates resemble those of lymphoid tissue. They suggest that chronic inflammatory tissue and normal lymphoid tissue share mechanisms of lymphocyte emigration.

The value of biopsy in patients with monarticular juvenile rheumatoid arthritis of recent onset

The histopathology of arthroscopic biopsy material from the knees of 8 patients with monarticular juvenile rheumatoid arthritis (JRA) of recent onset and of 4 control patients was examined using a histochemical method for acid alpha-naphthyl acetate esterase and an avidin-biotin-peroxidase complex method for different cell subtype-specific surface antigens. According to results of our prospective, single-blind study, nonspecific synovitis was observed in those biopsy samples obtained early in the course of disease. The samples were also characterized by cellular changes that are quite distinct from those described in patients with chronic rheumatoid synovitis. JRA must be considered the cause of symptoms if no orthopedic or infectious disease is found at arthroscopy in children with monarticular symptoms of recent onset and if nonspecific synovitis is observed in the histopathologic specimen. This pathologic description, however, does not correspond to that of classic rheumatoid synovitis. In our studies, we found that mononuclear cells displaying diffuse cytoplasmic esterase and surface Ia formed a large proportion of all inflammatory cells in situ. There were comparatively few activated Ia+ T cells and plasma cells. These observations suggest that exudative features and nonspecific cellular inflammation are prominent at onset of JRA. The immune response, in the form of immunocompetent T and B cells, seems to be more extensively involved in chronic JRA and may represent secondary features of the disease.

Current concepts in the treatment of rheumatoid arthritis

The treatment of RA is complex and often frustrating. The pathologic process of RA is composed of acute inflammation, chronic immunologic phenomenon, and chronic connective tissue degradation. It is important to understand not only the pathophysiology of RA but also the mechanism of action of our therapeutic drugs so that treatment can be tailored to affect the important aspects of the process leading to end-organ damage. Despite the many drugs available, therapy is still unsatisfactory. Many drugs work in only certain patients. This could be secondary to variability in the disease state or to difference in drug metabolism. A better understanding of both disease and therapeutic agents may lead to better use of our present agents and development of new, more effective treatment modalities.

Lymphocyte activation in rheumatoid arthritis synovial fluid in vivo

Monoclonal antibodies were used in avidin-biotin-peroxidase complex staining for activation marker analysis of rheumatoid synovial fluid cells. Although Ia expression indicates T cell activation, cells displaying receptors for interleukin 2 (Tac)-and transferrin receptor (T9)- positive proliferating cells were relatively few. Similarly, activated terminal effector cells of suppressor/cytotoxic nature were scarce in rheumatoid synovial fluid, as suggested by a low expression of Tac and 4F2 markers. The in vivo situation in the rheumatoid arthritic (RA) joint does not seem to be due to the inability of synovial fluid lymphocytes to become activated, because mitogen stimulation in vitro, in spite of a low proliferative response, induced expression of all the activation markers studied. The relevance of the present observations to the down-regulation of the active, inflammatory-immune response in situ is speculative, but the data show that in spite of T-cell activation and Ia expression, activated terminal effector cells of suppressor/cytotoxic nature are few in the RA joint in vivo.