Impaired antigen-specific suppressor cell activity in patients with rheumatoid arthritis

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.

Aberrant T-regulation in rheumatoid arthritis and IgA nephropathy affects CD5+ and CD5- B lymphocytes equally

T-suppressor function and T-helper function in healthy adults, elderly patients with non-immune diseases, and patients with rheumatoid arthritis (RA) and IgA nephropathy (IgAN) were titrated by adding graded concentrations of CD8+ cells to autologous CD8-depleted peripheral blood mononuclear cells (PBMC), or CD4+ cells to CD8- 4- PBMC, respectively. Following culture with pokeweed mitogen (PWM), numbers of CD5+ and CD5- immunoglobulin-secreting cells were determined using a combination of rosetting with anti-CD5-coated Dynabeads and reverse haemolytic plaque formation (Jones, 1990). Of 11 RA patients studied, eight had slightly reduced suppressor activity for CD5+ and CD5- IgM-secreting cells, and three with active disease and high serum levels of C-reactive protein, could not suppress IgG, IgA or IgM secretion by either B subset. Helper activity for both CD5+ and CD5- B cells was slightly but significantly increased in RA patients. One of eight patients with IgAN could not suppress IgG, IgA or IgM production by CD5+ or CD5- B cells, and all IgAN patients required strikingly fewer CD4+ cells for PWM-induced activation of CD5+ and CD5- B cells than controls. It was concluded that in two immunologically mediated diseases in which some patients have raised numbers of circulating CD5+ B cells, aberrant T-regulation affects CD5+ and conventional CD5- B cells equally.

Effects of a hydrosoluble bacterial extract from Escherichia coli (OM-89) on cytokine production by peripheral blood mononuclear cells from healthy subjects and patients with rheumatoid arthritis

OM-89 is a bacterial extract from escherichia coli, proposed as an immunomodulating drug for the treatment of rheumatoid arthritis (RA). Since immunological mechanisms may play a role in its action, the immunological effects of OM-89 were evaluated in vitro on peripheral blood mononuclear cells (PBMC) derived from healthy subjects and RA patients. Results indicated that in the absence of OM-89, production of the monokines interleukin-1 beta (IL-1 beta) and tumor necrosis factor-alpha (TNF-alpha) is increased, while that of the lymphokines interleukin-2 (IL-2) and interferon-gamma (IFN-gamma is decreased by phytohemagglutinin (PHA)-stimulated PBMC from RA patients as compared with PBMC from healthy subjects. In the presence of PHA, OM-89 enhanced the production of IL-1 beta, TNF-alpha, IL-2, and IFN-gamma. IL-1 beta and IL-2 curves obtained using increasing amounts of OM-89 did not differ depending on the source of PBMC. By contrast, in the presence of increasing amounts of OM-89, TNF-alpha secretion significantly higher and IFN-gamma secretion significantly lower with PBMC from RA patients compared to PBMC from healthy subjects. These data indicate that OM-89 acts on monocytes and T cells directly and/or indirectly and suggest a possible clinical activity by OM-89 in RA relative to its immunological properties.

Cellular immunosuppression in oral lichen planus

Functions of peripheral blood lymphocytes and neutrophils from 30 oral lichen planus (OLP) patients were examined using healthy persons as controls. Two-color flow cytometry of lymphocytes revealed no proportional difference in CD3 or CD4 cells between OLP and controls. CD8CD11b (suppressor T) and CD3HLA-DR+ cell populations increased significantly in OLP when compared with controls, and CD4/CD8 cell ratio decreased in OLP. Mitogenic response of patients' CD8 and CD4Leu8- cells was similar to that in controls. However, weaker blastogenesis of CD4Leu8+ cells, the most excellent responders in T cell subsets, was observed in OLP. Serum IFN beta level in OLP (8.4 +/- 4.8 IU/ml) was significantly lower than in controls (13.7 +/- 5.0 IU/ml) whereas no difference between the two groups could be found in IFN alpha or gamma. As for in vitro cytokine production by IL-2-stimulated lymphocytes, there was no difference in GM-CSF generation between the two groups, but, IFN gamma and IL1 beta production of patients' lymphocytes was less than that in healthy donors (57.6 +/- 50.7 VS 78.7 +/- 39.6 u/ml, 152.3 +/- 93.5 VS 258.7 +/- 65.4 pg/ml, respectively). Moreover, superoxide generation of patients' neutrophils by PMA stimulation was significantly insufficient as compared with controls' (84.9 +/- 30.9 VS 110.8 +/- 24.1 pmol/min/10(4) cells). Nevertheless, natural killer cell activities of both groups distributed in the same range. These results suggest that OLP patients' lymphocyte and neutrophil functions are impaired, and that cellular immunosuppression is a pathologic characteristic of OLP.

Spontaneous release of angiotensin converting enzyme and interleukin 1 beta from peripheral blood monocytes from patients with rheumatoid arthritis under a serum free condition

Angiotensin converting enzyme (ACE) and interleukin 1 activities were assayed simultaneously in the serum free medium from the unstimulated peripheral blood monocytes from 32 patients with rheumatoid arthritis (RA), 11 patients with osteoarthritis, and 25 normal controls matched for age and sex. Angiotensin converting enzyme activity was raised in most (29/32) patients with RA and interleukin 1 activity (most of which was interleukin 1 beta) was enhanced in 11/32 patients with RA, while monocytes from only two patients with osteoarthritis, but from none of the controls, secreted a small amount of ACE alone in the culture condition. Monocytes from patients with early RA (disease duration less than 3 years) released significantly more ACE and interleukin 1 than those from late stage RA (disease duration greater than or equal to 3 years).

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.

Immunomodulatory effect of a newly synthesized compound, TOK-8801 (N-(2-phenylethyl)-3,6,6-trimethyl-5,6-dihydroimidazo [2,1-b]thiazole-2-carboxamide) on antibody production in vivo and delayed-type hypersensitivity in mice

The immunopharmacological effects of a newly synthesized compound in vivo, TOK-8801 (N-(2-phenylethyl)-3,6,6-trimethyl-5,6-dihydroimidazo[2,1-b]thi azo le-2- carboxamide), on the anti-SRBC plaque-forming cell (PFC) response and delayed-type hypersensitivity (DTH) reaction were investigated. Oral administration of TOK-8801 (0.1-10 mg/kg) resulted in the suppression of the PFC responses to varying doses of antigen (5 x 10(6), 2 x 10(7), 1 x 10(8)) in C3H/He strain mice (7 W) which are high responders to SRBC antigen. On the other hand, the compound augmented the PFC response in aged mice (8-9 months) in which the PFC response was markedly depressed compared with that in young mice. In the experiment of the methylated human serum albumin-induced DTH reaction, TOK-8801 augmented the reaction in low responder (C57BL/6) mice by oral administrations of 0.1-1 mg/kg for 5 days from the sensitization, whereas suppressed the reaction in high responder (ICR) mice. These immunopharmacological actions of TOK-8801 were compared in dose and activity with those of lobenzarit and bucillamine. Thus, these results suggest that TOK-8801 may act as an immunomodulating agent and would be expected to be a useful agent for autoimmune diseases such as rheumatoid arthritis.

Abnormalities in CD4+ T-lymphocyte subsets in inflammatory rheumatic diseases

The monoclonal antibodies anti-2H4 and anti-4B4 identify the suppressor-inducer (CD4+2H4+) and helper-inducer (CD4+4B4+) subpopulations of CD4 (T4+) lymphocytes, respectively. The cell surface phenotype of peripheral blood lymphocytes and synovial fluid lymphocytes in patients with rheumatoid arthritis and other inflammatory joint diseases was analyzed by use of these and other well-characterized anti-T-cell monoclonal antibodies. In the synovial fluid of patients with rheumatoid arthritis, there was a markedly decreased percentage of T4+2H4+ suppressor-inducer cells (3.1 +/- 1 percent) and an increased percentage of T4+4B4+ helper-inducer cells (29.1 +/- 9 percent) as compared with the proportions found in the peripheral blood of normal individuals (T4+2H4+: 19.0 +/- 6 percent, T4+4B4+: 23.0 +/- 7 percent). Moreover, patients with other chronic and acute inflammatory joint diseases exhibited highly similar synovial T-cell findings to those of the patients with rheumatoid arthritis (T4+2H4+: 4.2 +/- 3 percent, T4+4B4+: 33.1 +/- 9 percent). In contrast, there were no significant differences between the normal control subjects and patients with rheumatoid arthritis in the percentage of T4+2H4+ cells in peripheral blood lymphocytes, nor were there significant differences between normal control subjects, patients with rheumatoid arthritis, and patients with other joint diseases (osteoarthritis, gout, B27+ spondyloarthropathy, and psoriatic arthritis) in the number of T4+4B4+ cells or in the T4/T8 ratio of peripheral blood lymphocytes. However, very low numbers of T4+2H4+ (suppressor-inducer) peripheral blood lymphocytes were seen in a subgroup of patients, including five of seven with Reiter's syndrome and several patients with systemic rheumatic disease syndromes. In addition, although the percentage of T4+2H4+ cells in peripheral blood lymphocytes of patients with osteoarthritis (13.7 +/- 7 percent) and gout (14.3 +/- 7 percent) was decreased compared with that of normal controls (19.0 +/- 6 percent) (osteoarthritis versus normal controls p less than 0.025), this difference appeared to reflect alterations due to age rather than disease. Consistent with the phenotypic changes observed, synovial T cells were also functionally defective, since autologous mixed lymphocyte reaction-activated T4 cells from the synovial fluid of patients with rheumatoid arthritis failed to exhibit suppressor-inducer activity.(ABSTRACT TRUNCATED AT 400 WORDS)

Abnormal distribution of the helper-inducer and suppressor-inducer T-lymphocyte subsets in the rheumatoid joint

T lymphocytes can be divided into two main phenotypic populations, CD4 and CD8. These can be further subdivided into 2H4, 4B4, or UCHL1 subsets by appropriate monoclonal antibodies. We have investigated these subsets in the synovial fluid of patients with rheumatoid arthritis and have found (i) a virtual absence of CD4+ 2H4+ and the marked reduction of CD8+ 2H4+ T cells; (ii) a marked increase of CD4+ 4B4+ and CD8+ 4B4+ T cells; and (iii) a marked increase of CD4+ UCHL1+ and CD8+ UCHL1+ T cells compared with peripheral blood. Although the functions of the CD8 subsets are not known, the virtual absence of CD4+ 2H4+ suppressor-inducer T cells and the marked increase of CD4+ 4B4+ helper-inducer T cells and of CD4+ UCHL1+ memory T cells may help to explain the many known functional immunological properties of synovial T cells.

Analysis of the antigen specific helper T cell function and HLA-DR of Israeli patients with rheumatoid arthritis (RA)

Forty-three patients with rheumatoid arthritis (RA) were studied for their ability to respond to the synthetic polypeptide antigen (T, G)-A-L as measured by the production of a T cell helper factor by their antigen activated T cells. Sixteen patients (37%) responded to (T, G)-A-L by the production of an antigen specific helper T cell factor, a percentage not significantly different from healthy donors. The production of antigen specific T cell helper factors was affected, although not significantly, by immune modulating drugs and by the presence of rheumatoid factor in sera of patients. The high incidence of HLA-DR 4 reported for RA patients was not observed in this group of RA patients.

Frequency and significance of antibody to double-stranded DNA in chronic active hepatitis

To assess the frequency and significance of immunoglobulin G antibody to double-stranded DNA in chronic active hepatitis, 99 patients with severe disease were tested for the antibody by an enzyme-linked immunosorbent assay of established sensitivity and specificity. Antibody was detected in 56 patients (57%) and occurred with similar frequency in patients with autoimmune (64%), idiopathic (46%) and type B (43%) disease. The mean serum level of antibody was higher in autoimmune disease but it was not significantly different from that in the other diagnostic categories. Patients with and without the antibody could not be distinguished by clinical, laboratory or histologic findings. Responses to corticosteroid therapy and mortality were unrelated to antibody status. In five patients, the antibody disappeared after corticosteroid treatment and induction of histologic remission. We conclude that immunoglobulin G antibody to double-stranded DNA is frequently present in patients with severe chronic active hepatitis. Patients with autoimmune disease may have higher antibody levels than others, but the presence of antibody does not connote a disease of specific etiology, unique presentation or different behavior. The prevalence of the finding and its disappearance after corticosteroid therapy suggest that it is a nonspecific manifestation of inflammatory activity.

Functional capacities of T lymphocyte subsets from synovial fluid and blood in rheumatoid arthritis

A reverse haemolytic plaque forming cell (PFC) assay was employed to analyse the impact of T suppressor/cytotoxic and T helper cells on B cell function in 10 patients with rheumatoid arthritis (RA). In all cases T8-enriched cells from synovial fluid and blood suppressed the pokeweed mitogen (PWM) induced IgM, IgG, and IgA secretion by autologous lymphocytes to the same degree. The suppression was partly abolished by irradiation of T8-enriched cells. T4-enriched cells from blood increased the PWM induced Ig secretion by autologous blood B cells. In six of 10 patients responses 1.2 to four times higher were obtained with T4-enriched cells from synovial fluid, but in four of 10 patients synovial fluid T4-enriched cells did not increase the PWM responses of blood B cells. T4- and T8-enriched T cells from synovial fluid comprised more Ia+ cells than did T cells from blood (36% v 3% and 43% v 6%). Ia+ T helper and suppressor/cytotoxic cells may modulate in vivo activation of synovial B cells in RA.

In vitro stimulation of lymphocytes from patients with rheumatoid arthritis

Peripheral blood lymphocytes from patients with rheumatoid arthritis (RA) and from normal controls were compared in 20 microliters droplet cultures following stimulation with phytohemagglutinin or concanavalin A. The dynamics of proliferation were significantly changed in RA. Higher numbers of cells in culture were needed to achieve the same response. This may explain the low proliferative responses of lymphocytes from some patients with RA, and apparent changes of in vitro suppressor effects, reported by other authors. Diurnal variations of lymphocytes in RA patients were also studied. No differences in the response to mitogen of lymphocytes taken at 7 AM and 7 PM were found.

A general strategy for the use of allogeneic lymphocyte infusions in the treatment of disorders characterized by impaired helper or suppressor T cell function: autoimmune diseases and the acquired immunodeficiency syndrome (AIDS)

Allogeneic lymphocytes can exert very potent non-specific immunomodulatory effects both in vitro and in vivo. Repeated infusions of allogeneic suppressor or helper populations may find use in the treatment of diseases characterized by impaired suppressor function (such as many autoimmune diseases) or impaired helper function (such as AIDS), respectively. Nutritional adjuvants for use with allogeneic suppressor therapy may include essential fatty acids, zinc, selenium, and vitamin E; the latter two nutrients as well as vitamin C and beta carotene may have value as adjuvants for allogeneic helper therapy. In a small preliminary trial, long-lasting normalization of rheumatoid factor titers and clinical symptoms has been achieved in 5 of 7 cases of chronic rheumatoid arthritis treated with allogeneic lymphocyte infusions, selenium, and vitamin E. These results indicate that allogeneic lymphocyte infusions accompanied by antioxidant support can promote the induction of new appropriate suppressor activity in the host. This phenomenon of allogeneic suppressor induction may be more clinically important than direct allosuppression of host B cells under the conditions of this study, and may find application in the treatment of a number of autoimmune disorders.

Spontaneous and aggregated IgG induced rheumatoid factor producing cells in rheumatoid arthritis

Seropositive rheumatoid arthritis (RA) patients were found to have high numbers of spontaneously occurring cells making rheumatoid factor (RF) reactive with human IgG as measured by a RF plaque forming cell (RF-PFC) assay. There was a significant positive correlation between the number of RF-PFC and both disease activity measured by the sedimentation rate and RF titer measured by the RA latex test. Aggregated IgG and pokeweed mitogen were equally effective stimulators of RF-PFC in cultures of RA peripheral blood mononuclear leukocytes. The rheumatoid ratio of helper (T4): suppressor (T8) T lymphocytes was also significantly increased over the ratio of normal controls, but this ratio did not correlate with the number of RF-PFC. Aggregated IgG or immune complexes may be responsible for stimulating RA RF-PFC in vivo.

Suppressor T cell function in patients with rheumatoid arthritis complicated by vasculitis

Concanavalin A (Con A)-induced suppressor T cell activity was determined in 10 rheumatoid arthritis (RA) patients with vasculitis, 34 RA patients without vasculitis, and 10 healthy individuals. The percent Con A-induced suppression in RA patients with vasculitis was 24.6. In contrast, it was 68.4% in those RA patients without vascular lesions. Further, the proportion of T cells reactive with OKT8 monoclonal antibody was also decreased in RA patients with vasculitis. Accordingly, the reduced Con A-induced suppressor T cell activity in these RA patients resulted, in part, from the reduction in the number of cells of the suppressor T cell subset. Those patients with vascular lesions also had a higher percentage of positive antilymphocytotoxic antibodies than RA patients without vasculitis. Since the differences in Con A-induced suppressor T cell activity and frequency of positive antilymphocytotoxic antibodies were so great, we believe RA patients with vasculitis could be recognized as a disease group distinct from RA patients without vasculitis.

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.

T-cell immunoregulatory functions in rheumatoid arthritis patients

We have studied the immunoregulatory function of T8+ (suppressor/cytotoxic) and Leu3a+ (inducer/helper) T cells from rheumatoid arthritis (RA) patients by measuring the effect of these T-cell subpopulations on the generation of immunoglobulin-secreting cells by normal allogeneic B cells after stimulation with pokeweed mitogen (PWM) in vitro. When T8+ or Leu3a+ cells from blood or synovial tissue from nine patients were substituted for T8+ or Leu3a+ cells, respectively, from normal blood mononuclear cells (MNC), RA T8+ cells showed an increased suppressor activity, whereas RA Leu3a+ cells were, except for one patient, weak augmentors. Unreplaced normal MNC and MNC replaced with allogeneic normal T-cell subpopulations responded equally to PWM. When T8+ plus Leu3a+ cells from the same patient replaced normal T cells, high B-cell responses were detected. Normal T8+ plus Leu3a+ cells generally supported the response to a lower degree. Substitution with two allogeneic T-cell subpopulations did not result in a B-cell response to PWM. Thus, whereas RA T8+ seemed to be strong suppressors and RA Leu3a+ cells weak augmentors by themselves, together they are possibly able to generate a B-cell stimulatory potential that might be of pathogenetic significance in the patients.

Contrasting relations between suppressor-cell function and suppressor-cell number in chronic liver disease

75 patients with various chronic liver diseases were investigated by simultaneous assay of suppressor-cell function and enumeration of suppressor T cells by monoclonal antibody. In chronic active hepatitis and primary biliary cirrhosis, substantial defects in suppressor-cell function were associated with negligible alterations in the proportions of suppressor cells. Defective suppressor-cell function was also evident in most patients with HBsAg-positive liver disease and in some with alcoholic liver disease. While the expected relations between suppressor-cell function and the proportions of helper or suppressor cells and the helper/suppressor ratio were apparent in alcoholic liver disease, the results in the HBsAg-positive, HBeAg-positive patients were in direct contrast. This apparent anomaly may reflect functional heterogeneity of the lymphocyte population detected by the monoclonal antibody OKT8, which identifies suppressor and cytotoxic cells. This study demonstrates that in the absence of simultaneous measurement of function, enumeration of T-cell subsets with monoclonal antibodies is an inadequate assessment of immunoregulatory balance.

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.

Impaired conA suppressor cell activity in patients with rheumatoid arthritis shows normalization during fasting

Normal controls and patients with rheumatoid arthritis (RA) were investigated with respect to quantitative lymphocyte proliferation (LP) after concanavalin-A (conA) activation and to conA-induced suppressor cell activity (conA-SC). Measurements and assessment of RA activity were made at the beginning and end of a 10-day fast. The controls showed depressed (p less than 0.05) LP at the end of the fast, but no change in conA-SC activity. The RA group showed subnormal (p less than 0.05) LP and conA-SC (p less than 0.01) at the beginning of the experiment. After fasting they showed clinical improvement, the LP was not further depressed, and the initially low conA-SC had become normal.

Effect of corticosteroids on suppressor-cell activity in "autoimmune" and viral chronic active hepatitis

We detected a severe defect in concanavalin A-induced suppressor-cell activity in 22 patients with "autoimmune" chronic active hepatitis and in 26 patients with hepatitis B surface antigen (HBsAg)-positive chronic active hepatitis, as compared with 20 control subjects (P less than 0.01). Normal values were observed in 21 patients with "autoimmune" hepatitis in whom a remission had been induced and maintained by treatment with prednisolone. When lymphocytes from patients with autoimmune chronic active hepatitis were preincubated with low-dose prednisolone in vitro, suppressor-cell activity was substantially improved (P less than 0.01), but no clear effect of prednisolone was seen in cells from patients with HBsAg-positive chronic active hepatitis. The loss of suppressor-cell activity in chronic active hepatitis may allow liver damage to continue, and the reversal of the defect in the autoimmune form of the disease by administration of low-dose prednisolone provides a plausible explanation for the efficacy of this treatment. The contrasting in vitro responses to prednisolone in autoimmune and HBsAg-positive chronic active hepatitis suggest that the fundamental nature of the suppressor-cell defect may be different in these two forms of the disease.

Effects of methyl-B12 on the in vitro immune functions of human T lymphocytes

Studies were performed using an in vitro assay system to determine whether or not methyl-B12 could affect human T-cell function. When T cells were stimulated with phytohemagglutinin and allogeneic B cells, methyl-B12 did not enhance T-cell proliferation. In contrast, remarkable enhancing effects of methyl-B12 on the proliferative response to concanavalin A (Con A) and autologous B cells at suboptimal concentrations were observed, ranging from 0.1 to 10 micrograms/ml. Concentrations of methyl-B12 sufficient to enhance cellular proliferation were able to enhance the activity of helper T cells for immunoglobulin synthesis of B cells by pokeweed mitogen. Furthermore, the presence of methyl-B12 significantly potentiated the induction of suppressor cells in Con A-activated cultures. These results suggest that methyl-B12 could modulate lymphocyte function through augmenting regulatory T-cell activities.

Immunity to homologous type III collagen after partial meniscectomy and sham surgery in rabbits

Cellular immunity to rabbit types I, II, and III collagen was detected after both partial medial meniscectomy and sham operation in rabbits when an in vitro 3H-thymidine incorporation assay was used. The blastogenic responses were commonly directed towards peptides derived from collagens by cyanogen bromide cleavage used to mimic proteinase degradation products. The responses to type III collagen peptides were by far the strongest and were seen in most rabbits that were operated on. We suggest that the responses to types I and II collagen were caused by a cross-reaction with type III collagen peptides. This conclusion was supported by the observation that spleen cells from rabbits directly immunized with homologous type III collagen peptides in Freund's complete adjuvant responded strongly to the immunizing peptides and also cross-reacted with types I and II collagen peptides. Immunity to cartilage proteoglycans was observed primarily in rabbits that had undergone meniscectomy and had severe cartilage degeneration. These results indicated that immunity to collagens will develop merely as a result of joint surgery, whereas immunity to proteoglycans is largely dependent upon an osteoarthritic lesion.

Impaired antigen-specific suppressor cell activity in psoriasis and psoriatic arthritis

Antigen specific suppressor cell activity of peripheral blood mononuclear cells was investigated in 20 patients with psoriatic arthritis and 18 patients with uncomplicated psoriasis and compared to that of 27 age- and sex-matched healthy controls and 18 patients with osteoarthritis. Topical skin therapy and nonsteroidal anti-inflammatory medications were allowed but patients who had taken disease suppressive, immunosuppressive, cytotoxic, and systemic steroid therapy were excluded. The results demonstrate reduced suppressor cell activity (SCA) in patients with psoriatic arthritis compared to normal controls (54.8% +/- 4.9 vs 68.4 +/- 2.8, p less than 0.005). Similarly, the response of patients with uncomplicated psoriasis was significantly lower than normal (50.1 +/- 4.9 vs 67.3 +/- 3.0% p less than 0.005). Five of the 20 patients with psoriatic arthritis and 7 of the 18 patients with uncomplicated psoriasis demonstrated SCA of more than 2 SD below the normal mean. The SCA of patients with osteoarthritis was normal. The plaque forming cell (PFC) response of patients with psoriatic arthritis and uncomplicated psoriasis was not different from those of the normal controls or of patients with osteoarthritis. There was no correlation between impaired suppression and disease activity or therapy.

Effect of the immune modulators BM 12.531 (azimexone) and BM 41.332 on the subsets of T-lymphocytes in mice

The immunomodulating 2-cyanaziridine derivatives BM 12.531 (azimexone) and BM 41.332 have no effects on the total amount of T-lymphocytes in the spleen of mice but increase dose-dependently the percentage of Ly1-, 2+, 3+ T-lymphocytes (killer/suppressor) and decrease the percentage of Ly1+, 2-, (helper) cells. These investigations were carried out by means of specific monoclonal antibodies and fluorescence-activated cell sorting. The increase in Ly2+-cells is mainly due to increased suppressor activity.