Abnormal T suppressor cell function in juvenile rheumatoid arthritis

Neutrophils Lose the Capacity to Suppress T Cell Proliferation Upon Migration Towards Inflamed Joints in Juvenile Idiopathic Arthritis

Neutrophils are highly abundant in synovial fluid of rheumatic inflamed joints. In oligoarticular juvenile idiopathic arthritis (JIA), synovial fluid neutrophils have impaired effector functions and altered phenotype. We hypothesized that these alterations might impact the immunoregulatory interplay between neutrophils and T cells. In this study we analyzed the suppressive effect of neutrophils, isolated from blood and synovial fluid of oligoarticular JIA patients, on CD4⁺ T cells activated by CD3/CD28 stimulation. JIA blood neutrophils suppressed T cell proliferation but synovial fluid neutrophils from several patients did not. The loss of T cell suppression was replicated in an in vitro transmigration assay, where healthy control neutrophils migrated into synovial fluid through transwell inserts with endothelial cells and synoviocytes. Non-migrated neutrophils suppressed proliferation of activated CD4⁺ T cells, but migrated neutrophils had no suppressive effect. Neutrophil suppression of T cells was partly dependent on reactive oxygen species (ROS), demonstrated by impaired suppression in presence of catalase. Migrated neutrophils had reduced ROS production compared to non-migrated neutrophils. A proteomic analysis of transwell-migrated neutrophils identified alterations in proteins related to neutrophil ROS production and degranulation, and biological processes involving protein transport, cell-cell contact and inflammation. In conclusion, neutrophils in synovial fluid of children with JIA have impaired capacity to suppress activated T cells, which may be due to reduced oxidative burst and alterations in proteins related to cell-cell contact and inflammation. The lack of T cell suppression by neutrophils in synovial fluid may contribute to local inflammation and autoimmune reactions in the JIA joint.

Successful treatment in a child with enthesitis-related arthritis involving the sternoclavicular joint: a case report

Background

Although the sternoclavicular joint (SCJ) may be involved in ankylosing spondylitis, rheumatic arthritis, and Behçet’s disease and participates in the systemic inflammatory process of arthritis, it is often neglected during routine rheumatologic clinical examinations. To the best of our knowledge, this is the first study to report etanercept treatment in juvenile idiopathic arthritis (JIA) with SCJ involvement.

Case presentation

In this study, we describe an unusual case of a child with juvenile idiopathic arthritis with an initial presentation of sternoclavicular mass. The patient (age, 14 years 10 months) presented with an insidious onset atraumatic swelling of the left SCJ and complained of right hip and bilateral ankle tenderness without an apparent cause. Initial ultrasonography indicated a heterogeneous mass in the left SCJ, while computed tomography identified mild swelling of the left SCJ with a thickened synovial lining, mild bone erosion, and some turbid fluid. The patient ultimately underwent left SCJ arthrotomy, during which tapping of the SCJ revealed 2 cc of yellowish fluid, inflammation and necrosis of tissues within the SCJ. A clear yellow joint fluid was aspirated, and testing revealed a negative culture result. The patient was diagnosed with JIA. The joint tenderness improved and erythrocyte sedimentation rate decreased after administering anti-tumor necrosis factor etanercept. An additional ultrasonography demonstrated that the initial imaging findings have been resolved. At the end of a 2-year follow-up period, the patient was completely symptom-free.

Conclusions

JIA with SCJ involvement is an uncommon presentation in adolescents. Etanercept may be a beneficial treatment for SCJ involvement in patients with JIA. The upper limbs showed no signs of limited range of motion during the follow-up period. Further studies are warranted to elucidate the efficacy of etanercept in JIA with sternoclavicular joint involvement.

Polyclonal and monoclonal antibodies in clinic

Immunoglobulins (Ig) or antibodies are heavy plasma proteins, with sugar chains added to amino-acid residues by N-linked glycosylation and occasionally by O-linked glycosylation. The versatility of antibodies is demonstrated by the various functions that they mediate such as neutralization, agglutination, fixation with activation of complement and activation of effector cells. Naturally occurring antibodies protect the organism against harmful pathogens, viruses and infections. In addition, almost any organic chemical induces antibody production of antibodies that would bind specifically to the chemical. These antibodies are often produced from multiple B cell clones and referred to as polyclonal antibodies. In recent years, scientists have exploited the highly evolved machinery of the immune system to produce structurally and functionally complex molecules such as antibodies from a single B clone, heralding the era of monoclonal antibodies. Most of the antibodies currently in the clinic, target components of the immune system, are not curative and seek to alleviate symptoms rather than cure disease. Our group used a novel strategy to identify reparative human monoclonal antibodies distinct from conventional antibodies. In this chapter, we discuss the therapeutic relevance of both polyclonal and monoclonal antibodies in clinic.

Quantitative alterations of CD8+ T cells in juvenile idiopathic arthritis patients in remission

The study was aimed to investigate whether quantities of CD8(+) T cell subsets are normal in juvenile idiopathic arthritis (JIA) patients with disease remission compared to age-matched healthy donors (HD) and whether chronological age may have an impact on proportions of naive CD8(+) T cells. CD8(+) T cell subsets were analyzed in 17 JIA patients and 32 age-matched HD by flow cytometry. JIA patients showed lower CD3(+)CD8(+) T cells compared to HD. Total counts of CD8(+)CD28(+) and CD8(+)CD28(+)CD45RA(+) T cells were inversely correlated to chronological age in JIA patients and HD. In JIA patients, percentages of CD8(+)CD28(+)CD45RA(+) T cells and of CD62L-expressing CD8(+)CD28(+)CD45RA(+) T cells showed a negative correlation with age. The trend to lower CD28(+)CD45RA(+) T cell proportions in aged JIA patients in remission may reflect a disturbed T cell homeostasis independently of disease activity and may be due to an intrinsic effect in reconstitution of the peripheral T cells.

Assessment of the peripheral immunocompetent cells in patients with reticular and atrophic-erosive lichen planus

OBJECTIVE

To assess the cellular and humoral immunity in patients with reticular and atrophic-erosive oral lichen planus (OLP).

STUDY DESIGN

Lymphocyte phenotype analysis of 50 patients with OLP and 16 control subjects was performed by means of flow cytometry. The results were analyzed by the Mann-Whitney U test.

RESULTS

In the patient group the percentage of naïve helper T cells was significantly decreased, while that of memory cells was increased, resulting in a significantly higher ratio of memory to naïve cells in the OLP group than in the control group. In the group of patients with atrophic-erosive OLP, the percentages of cytotoxic/suppressor T cells and cytotoxic/suppressor naïve T cells were found to be slightly decreased.

CONCLUSIONS

The results indicate that the relative ratio of immunocompetent cells in the peripheral blood is altered in patients with lichen planus and that the exact character of these disturbances depends on OLP form. Some of the alterations observed in these patients are typical to autoimmune diseases, thus promoting the concept of autoimmune etiopathogenesis of lichen planus.

Treatment options for juvenile-onset systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is an inflammatory chronic disease characterized by the presence of activated helper T-cells that induce a B-cell response, resulting in the secretion of pathogenic autoantibodies and the formation of immune complexes. SLE in children is a disease of low prevalence with a wide range of clinical manifestations, which means that the number of randomized controlled studies are few and usually involve a small number of patients. In recent years, new therapeutic agents have appeared and the role of older treatments has been clarified. Many of these treatments are designed to reduce inflammation. The spectrum is broad and ranges from traditional nonsteroidal anti-inflammatory drugs (NSAIDs) to cytotoxic agents that have anti-inflammatory effects. The current treatment of children or adults depends on the clinical expression of the disease. Minor manifestations usually respond to the administration of NSAIDs, low doses of corticosteroids, hydroxychloroquine, or methotrexate. Thalidomide could be used for refractory skin lesions. Major manifestations can endanger the patient's life and require early, aggressive treatment. Kidney disease and other manifestations have been related to the formation or deposit of tissular immune complexes. Therefore, for years the main aim of treatment has been to suppress the immune response. The immunosuppressant treatments used in children with SLE include high doses of corticosteroids, azathioprine, methotrexate, cyclosporine, and cyclophosphamide. Several combinations of medications have been used to obtain a rapid remission or to reduce the risk of toxicity of prolonged administration of cytotoxic agents. Intravenous gamma-globulin has been successfully used in the treatment of lupus nephritis, vasculitis, and acute thrombocytopenia. In spite of numerous published studies, the use of these drugs is still controversial. The immunosuppression achieved with these treatments is nonspecific, not always effective, and associated with significant toxicities; the most significant being growth retardation, accelerated atherosclerosis and severe infectious complications. The purpose of new biological therapies is to achieve specific immunosuppression, which makes it possible to design more effective and less toxic therapeutic strategies. Mycophenolate mofetil is a promising alternative in patients who do not respond to high doses of cyclophosphamide or azathioprine. Some recently developed monoclonal antibodies such as anti-CD40L or anti-IL-10, or other molecules such as LJP394 may prove useful in the near future. Finally, stem cell transplantation may be proposed in patients with severe juvenile-onset SLE who do not respond to any treatment.

Juvenile rheumatoid arthritis-like polyarthritis in chromosome 22q11.2 deletion syndrome (DiGeorge anomalad/velocardiofacial syndrome/conotruncal anomaly face syndrome)

OBJECTIVE

To investigate the association of polyarthritis and chromosome 22q11.2 deletions.

METHODS

Eighty patients with chromosome 22q11.2 deletion syndrome followed up at The Children's Hospital of Philadelphia were examined for evidence of arthropathy or arthritis. Patients with chromosome 22q11.2 deletion syndrome and polyarthritis underwent laboratory evaluations of immunologic function to determine the relationship of their immunodeficiency to the polyarthritis.

RESULTS

The prevalence of polyarthritis in patients with chromosome 22q11.2 deletion syndrome was markedly increased over the prevalence of polyarticular juvenile rheumatoid arthritis (JRA) in the general population. All 3 patients with polyarthritis had evidence of impaired T cell function. Two of the patients with polyarthritis also had IgA deficiency.

CONCLUSION

The chromosome 22q11.2 deletion syndrome represents a primary T cell disorder which can be associated with a JRA-like polyarthritis. All 3 patients with polyarthritis had evidence of more extensive immunoregulatory derangements than those typically seen in patients with chromosome 22q11.2 deletion, and these derangements may have predisposed to the development of polyarthritis.

Juvenile rheumatoid arthritis in velo-cardio-facial syndrome: coincidence or unusual complication?

We report on two patients with velo-cardio-facial syndrome (VCFS) and juvenile rheumatoid arthritis (JRA). The first, a 9-year-old girl, presented with microcephaly, characteristic face, congenital heart disease, and velopharyngeal insufficiency. Fluorescence in situ hybridization (FISH) study showed deletion of D22S75 (N25), confirming the diagnosis of VCFS. At age 7, she developed joint pain, and polyarticular JRA was diagnosed. Awareness of this case led to the subsequent diagnosis of VCFS (also confirmed by FISH) in another, unrelated 12-year-old girl with characteristic face, hypernasal speech, and obesity. JRA was first diagnosed in this case at age 5 years, and she subsequently developed severe polyarticular disease. Neither patient had clinical or laboratory evidence of immunodeficiency. This observation represents the first report of the association of JRA with VCFS and raises the question of whether this is a coincidental association or a rare complication of this condition.

Immunopathogenesis of juvenile rheumatoid arthritis: role of T cells and MHC

Juvenile rheumatoid arthritis (JRA) is defined as chronic arthritis of unknown etiology appearing in patients less than 16 years of age. The disease is heterogeneous and is classified as pauciarticular, polyarticular, or systemic-onset disease. A few lines of evidence suggest that T cells are involved in the pathogenesis of the disease. T cells infiltrating the synovial membrane bear markers of activation and produce cytokines. The association of particular subtypes of JRA with certain HLA class II alleles provides strong evidence in favor of T cell involvement through an HLA-peptide-T cell receptor complex. Limited data from a few patients with JRA on T cell receptor transcripts from synovial membrane or synovial fluid cells point towards oligoclonality. This further supports the concept that T cells infiltrating the synovial membrane or extravasating into synovial fluid in patients with JRA reflect antigen-driven T cell proliferation.

Alterations in levels of CD28-/CD8+ suppressor cell precursor and CD45RO+/CD4+ memory T lymphocytes in the peripheral blood of multiple sclerosis patients

A comprehensive peripheral blood immunophenotype analysis of 16 multiple sclerosis (MS) patients was performed by three-color flow cytometric analysis, and the results were compared with those for age-matched healthy controls. The cell subsets quantified included T cells (CD3+), B cells (CD19+), NK cells (CD56+), CD4+ and CD8+ T cells, cytotoxic (CD28+) and suppressor precursor (CD28-) CD8+ T cells, CD45RA+ and CD45RO+ T cells (CD4+ and CD8+), and CD5+ T and B cells. Analysis of MS patients' peripheral blood revealed essentially normal levels of total T, B, and NK cells. In agreement with results obtained by other investigators, it was found that MS patients had an increased CD4/CD8 ratio, primarily due to a decrease in CD8+ T cells. MS patients were found to have a significantly decreased level of suppressor precursor (CD28-) CD8+ T cells compared with that of controls but to have normal levels of cytotoxic (CD28+) CD8+ T cells. These data indicate that MS patients do not have a general decrease in CD8+ T cells but that they have a specific decrease in the suppressor precursor subset only and normal levels of cytotoxic CD8+ T cells. MS patients also had a significant increase in memory (CD45RO+) CD4+ T cells and displayed a trend towards a decrease in naive (CD45RA+) T cells in the peripheral blood.

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.

Synovial fluid cells in juvenile arthritis: evidence of selective T cell migration to inflamed tissue

The perpetuation of chronic synovitis in juvenile arthritis (JA) is a complex interaction of local and systemic regulatory mechanism. We examined the cell surface phenotype of synovial fluid cells and peripheral blood lymphocytes from 15 patients with JA to better understand the mechanism of local inflammation. Synovial fluid and peripheral blood mononuclear cells were analysed for cell surface expression of CD2, CD3, CD4, CD8, CD19, CD25, CD29, CD45R and Ia using flow cytometry. We found a very low percentage of B cells with a concomitant increase of T cells in synovial fluid as compared with peripheral blood. A large percentage of the synovial fluid T cells were HLA-DR+, or activated T cells, and there was a relative decrease in CD4+ cells in synovial fluid as compared with peripheral blood. There was only a minimal increase in CD25+ synovial fluid cells. The synovial fluid CD4+ cells were mainly of the CD2high, CD29+, CD45RO phenotype. This CD4 phenotype found on synovial fluid cells from patients with JA and in particular the CD29 cell surface marker, which recognizes a common beta-chain of adhesion molecules, is associated with binding to extracellular matrix proteins and is also associated with 'primed' T cells. Our results demonstrated the presence of T cells which either selectively migrate to synovium and synovial fluid or are activated in situ in the joint.

Suppressor cell function in oral lichen planus

Oral lichen planus (OLP) is a common inflammatory condition of the oral mucous membranes which affects between one and two percent of the general population. In accordance with the protracted clinical course of OLP and its association with known auto-immune diseases, the level of self-tolerance is questionable and possibly diminished in patients with this disorder. Normal suppressor T lymphocyte function is reputedly an essential element in the maintenance of self-tolerance, and deficient cell-mediated suppressor activity is implicated in the pathogenesis of auto-immune diseases. For assessment of in vitro cell-mediated suppressor activity in OLP, peripheral blood mononuclear cells (PBMC) from ten patients with OLP and from 11 control subjects were activated with the plant mitogen concanavalin A (Con A), followed by co-culture with autologous responder cells. The ability of irradiated Con A-activated cells to suppress the proliferation of Con A-stimulated responder cells was determined. Con A-induced suppressor activity of PBMC in the OLP patients was significantly less than that in control subjects (p = 0.001). Results of the present investigation complement previous in vitro findings which provided indirect evidence of deficient cell-mediated suppressor activity in OLP, particularly a decreased proportion of circulating CD4+CD45RA+ lymphocytes and reduced Con A-stimulated PBMC proliferation. The depressed Con A-induced suppressor activity of PBMC in the OLP patients provides direct evidence of deficient in vitro cell-mediated suppressor function in OLP, and suggests that defective cell-mediated suppressor circuits and reduced self-tolerance may be involved in the pathogenesis of this disorder.

Lymphokines and soluble interleukin-2 receptors in juvenile chronic arthritis. Clinical and laboratory correlations

Serum levels of interleukin (IL)-2, interferon gamma (IFNg) and soluble IL-2 receptors (sIL-2R) were determined in sera from 34 patients with poly- or pauciarticular juvenile chronic arthritis (JCA) by use of enzyme-linked immunosorbent assays (ELISAs). Levels of sIL-2R were elevated in the group of patients compared with those of healthy children and correlated significantly with several parameters of clinical activity, including the functional capacity, joint score, visual-analogue score and erythrocyte sedimentation rate (ESR). Serum IL-2 levels were also elevated in the JCA patients, correlating with the patients functional capacity. Serum levels of IFNg were below the detection limit of the assay. Our data supported the notion that T-cell activation plays a role in the immunopathologic processes leading to clinical JCA.

Phenotypic and functional characteristics of activated CD8+ cells: a CD11b-CD28- subset mediates noncytolytic functional suppression

Freshly isolated human CD8+ cells can be divided into mutually exclusive subsets bearing the phenotypes CD11b+(CD28-) or CD28+(CD11b-). We found that activation of CD8+ cells with anti-CD3 mAb and IL-2 preferentially expanded the CD11b-(CD28+) subset. This subset, when separated and activated independently, mediated both functional suppression and lectin-dependent cell cytotoxicity (LDCC). CD28- cells, prepared by elimination of the CD 28+ cells from expanded unfractionated CD8+ cell cultures, retained functional suppressor activity but demonstrated reduced LDCC compared to either the CD28+(CD11b-)-enriched fraction or the unfractionated CD8+ population. The majority of the CD28- cells were also CD11b-, reflecting the observation that initially CD11b+ cells lose CD11b expression following activation with anti-CD3 mAb and IL-2. Our results therefore indicate that CD8+ cells deriving from the CD11b+CD28- subset, but expressing neither CD11b nor CD28 after activation, represent the main noncytotoxic functional suppressor cell in the mitogen "activated" suppressor assay. The preferential expansion of CD8+CD28+ cells relative to CD8+CD28- cells, if occurring in vivo in the central nervous system (CNS) compartment, would be consistent with observed phenotypic analysis of cerebrospinal fluid-derived T cells and might contribute to the reduced functional suppressor activity previously found for CNS compared to peripheral blood-derived lymphocytes.

Regulation of human interleukin-2 and interferon-gamma gene expression by suppressor T lymphocytes

Concomitant with induction of interleukin-2 (IL-2) and interferon-gamma (IFN-gamma) gene expression in human tonsil cells, mitogenic stimulation induces a transient activation of cells able to effectively suppress expression of these genes. Induction of IL-2 and IFN-gamma genes largely precedes appearance of suppressor cell activity, allowing expression of both genes to occur before strong down-regulation is exerted by activated suppressor cells. Suppressive activity induced in one cell population can inhibit IL-2 and IFN-gamma gene expression in another population from the same donor. The distinct nature of suppressor cells is supported by the absence of down-regulation of IL-2 gene expression in a helper cell line, MLA-144; yet, in these cells, negative control can be expressed when active suppressor cells are introduced. Our findings support the concept that actual levels of IL-2 and IFN-gamma gene activity are regulated to a large extent by the differential kinetics of activation of suppressor cells on one hand and of cells expressing the IL-2 and IFN-gamma genes on the other.