Flow cytometric analysis of gut mucosal lymphocytes supports an impaired Th1 cytokine profile in spondyloarthropathy

OBJECTIVE: To quantify the fraction of gut mucosal lymphocytes expressing the T helper type 1 (Th1) cytokines, interferon gamma (IFNgamma) and interleukin (IL)2, and the Th2 cytokines, IL4 and IL10, at the single cell level in patients with spondyloarthropathy (SpA) in comparison with healthy controls. METHODS: An improved extraction protocol was used for the enrichment of intraepithelial lymphocytes (IELs) and lamina propria lymphocytes (LPLs) from colonic and ileal biopsy specimens obtained from patients with SpA (n=20) and healthy controls (n=13). After stimulation with phorbol ester/ionomycin, expression of the intracellular cytokines IFNgamma, IL2, IL4, and IL10 was determined in CD3+, CD3+CD8+ and CD3+CD8- T cells by flow cytometry. RESULTS: In colonic LPLs, a significant decrease in IFNgamma-producing CD3+ cells was observed (p=0.02) in patients with SpA. In the CD3+CD8- subset, the proportion of cells producing IFNgamma and IL2 was decreased in patients with SpA (p=0.021 and p=0.027 respectively). In ileal LPLs, the percentage of IL10-producing CD3+CD8- cells was significantly increased (p=0.046). CONCLUSION: An impaired Th1 cytokine profile is observed in gut mucosal lymphocytes from patients with SpA. This adds to the existing evidence that the gut mucosal immune apparatus is involved in the pathogenesis of SpA.     

High production of proinflammatory and Th1 cytokines by dendritic cells from patients with rheumatoid arthritis, and down regulation upon FcgammaR triggering

OBJECTIVE: To assess whether DC from RA produce altered cytokine levels and whether this is regulated by triggering of Fc gamma receptors (FcgammaR). METHODS: The production of proinflammatory (TNFalpha, IL1, IL6), Th1 (IL12, IFNgamma), and Th2 (IL10) cytokine profiles of immature DC (iDC) from patients with RA and healthy subjects upon triggering of FcgammaR dependent and independent pathways was investigated. iDC, derived from blood monocytes by standardised protocols, were stimulated with immune complexes (IC) at day 6 for 48 hours and, subsequently, for 2 days with LPS in the presence or absence of IC or IFNgamma, resulting in fully matured DC (mDC). IL1, IL6, TNFalpha, IFNgamma, IL12, and IL10 levels in supernatants were measured by ELISA and RIA. RESULTS: mDC from patients with RA showed a markedly increased production of IL1, IL6, TNFalpha, and IL10 compared with DC from healthy donors. Triggering of FcgammaR decreased the production of proinflammatory cytokines IL1, IL12, and IFNgamma by iDC and mDC in RA and controls. The production of IL6 and TNFalpha decreased in patients with RA, whereas it was increased in controls. Triggering of FcgammaR independent mechanisms using IFNgamma increased the production of proinflammatory and Th1 cytokines, which was more pronounced in RA. CONCLUSION: FcgammaR dependent pathways influence cytokine production by DC. A skewed balance towards proinflammatory and Th1 cytokines in RA can, at least partly, be restored by triggering FcgammaR on DC in RA. Insight into the mechanism which determines the FcgammaR balance might lead to new strategies to abrogate Th1 driven inflammatory processes in RA.     

Cytokine and chemokine receptor profile of peripheral blood mononuclear cells during treatment with infliximab in patients with active rheumatoid arthritis

OBJECTIVES: To analyse immunological changes during treatment with a monoclonal anti-tumour necrosis factor alpha (TNFalpha) antibody, infliximab, in patients with rheumatoid arthritis (RA). METHODS: 25 patients with RA and 5 patients with other arthritides were studied during the first 6 weeks of treatment with infliximab. At the start of treatment and after 2 and 6 weeks, spontaneous expression of CCR3 and CCR5 on peripheral blood T cells and monocytes was studied by flow cytometry. The secretion and mRNA expression of interferon gamma (IFNgamma), interleukin (IL)4, IL5, and TNFalpha from phytohaemagglutinin (PHA) stimulated peripheral blood mononuclear cells was measured with an ELISA and RT-PCR. Plasma levels of C reactive protein, serum amyloid protein A, rheumatoid factor, and antibodies to filaggrin and citrullinated cyclic peptide were measured with an ELISA. RESULTS: The number of CD4 T cells and CD14 monocytes expressing CCR3 (p = 0.013, p = 0.009, respectively) and CD8 T cells expressing CCR5 (p = 0.040) as well as PHA stimulated secretion of IL4 and IFNgamma (p<0.05) increased during treatment in patients with RA. 15 (60%) patients with RA achieved clinical response (at least ACR20) during the first 2 weeks. The number of T cells expressing CCR3 and CCR5 was higher before treatment in non-responders than in responders (p<0.05). The number of T cells increased in responders. CONCLUSION: Increase in secretion of Th1 and Th2 cytokines together with induced expression of chemokine receptors on T cells and monocytes suggest restoration of peripheral cell mediated immunity and blockade of the accumulation of inflammatory cells in joints as response to treatment.     

CD27+ memory and CD27- effector CD8+ T cells are responsible for a decreased production of proinflammatory cytokines in HLA B27-positive subjects

BACKGROUND AND OBJECTIVE: AS and other spondyloarthritides (SpA) are mostly chronic inflammatory rheumatic diseases characterised by a strong association with HLA B27. Recent data from our group have suggested that AS patients have a diminished secretion capacity of inflammatory cytokines, possibly associated with HLA B27. The aim of this study was to identify CD4+ and CD8+ T cell subsets responsible for the observed lower cytokine secretion capacity in HLA B27-positives. METHODS: Highly purified (> 98%) CD4+ and CD8+ T cells of HLA B27-positive AS patients (n = 13), healthy HLA B27-positive (n = 7) and -negative controls (n = 9) were stimulated for 6h with PMA/ Ionomycin and, after fixation, stained for surface markers CD45RA and CD27 and cytokines TNFalpha, IFNgamma, IL-4 and IL-10. RESULTS: CD27+ CD45RA- memory CD8+ T cells of HLA B27-positive subjects showed a significantly lower percentage of TNFalpha (median 71.4%) and IFNgamma production (median 69.7%) than HLA B27-negative controls (TNFalpha 85.1%; p < or = 0.027; IFNgamma 82.7%, p < or = 0.026). A similar result was also detected in CD27- CD45RA+ effector CD8+ T cells of which 43.2% produced TNFalpha and 66.3% IFNgamma in HLA B27-positive subjects, respectively, compared to 75.6% TNFalpha and 84.4% IFNgamma producing T cells in HLA B27-negatives (p < or = 0.045 and p < or = 0.062, respectively). For all CD4+ T cell subsets no significant differences between HLA B27-positive and HLA B27-negative donors were observed, regarding neither the frequency of IFNgamma, TNFalpha, IL-4 or IL-10 producers nor the coexpression of IFNgamma and IL-4 in memory subsets. CONCLUSIONS: HLA B27-positive subjects are characterized by a low proinflammatory cytokine production in CD8+ effector and memory T cell subsets. This suggests an influence of HLA B27 on cytokine production in antigen-experienced CD8+ T cells.     

Preferential type 1 chemokine receptors and cytokine production of CD28- T cells in ankylosing spondylitis

OBJECTIVE: To examine serum levels of type 1 and type 2 chemokines and lymphocytic expression of chemokine receptors, and to compare the results with lymphocytic cytokine production in patients with ankylosing spondylitis (AS). METHODS: Twelve patients with AS (mean (SD) age 44.9 (14.7) years) and 27 healthy controls (46.4 (12.8) years) were enrolled into the study. The expression of chemokine receptors (CCR-5, CXCR-3, CCR-4) and cytokines (interferon gamma (IFNgamma), interleukin (IL)2, IL4, IL10, tumour necrosis factor alpha (TNFalpha)) on CD28(+) and CD28(-) T cell subtypes was analysed by a three colour FACS technique of peripheral blood samples. Serum ELISAs were performed to detect the CCR-5 ligands CCL-5, CCL-3; the CXCR-3 ligands CXCL-10, CXCL-9; and the CCR-4 ligand, CCL-17 before and after administration of the TNFalpha blocking agent infliximab. RESULTS: CD4(+)CD28(-) T cells had higher ratios of CXCR-3 to CCR-4 than CD4(+)CD28(+) T cells. Both, CD4(+) and CD8(+)CD28(-) T cells of patients with AS produced more IFNgamma, TNFalpha, and IL10 than their CD28(+) counterparts (p<0.05), and lacked the production of IL2 and IL4. Serum levels of CXCL-9 were increased in patients with AS to 59.2 pg/ml (34.1-730.5) compared with 32.5 pg/ml (20.0-79.5) in healthy controls (p = 0.016). The levels of both type 1 (CCL-5, CXCL-9) and type 2 chemokines (CCL-17) decreased under blockade of TNFalpha (p<0.05). CONCLUSIONS: The profile of chemokine receptor expression and cytokine production by CD28(-) T cells suggests a type 1 immune reaction in AS, although IL10 is frequently produced by CD28(-) T cells. Treatment with TNFalpha blocking antibodies decreased both types of chemokines in patients' sera.     

Treatment with monoclonal anti-tumor necrosis factor alpha antibody results in an accumulation of Th1 CD4+ T cells in the peripheral blood of patients with rheumatoid arthritis.

OBJECTIVE: In rheumatoid arthritis (RA), treatment with tumor necrosis factor alpha (TNFalpha) binding agents has proven to be highly effective. Downregulation of the proinflammatory cytokine cascade and a reduced migration of leukocytes into the joints have been proposed as modes of action of TNFalpha blockade. We investigated whether alterations in the number of circulating pro- and antiinflammatory T cell subsets contribute to the therapeutic effect of monoclonal antibodies (mAb) against TNFalpha in RA patients. METHODS: Phenotypic analysis of peripheral blood T cell subsets was performed on blood from RA patients before and after treatment with an anti-TNFalpha mAb. RESULTS: An accumulation of primed CD45RA- T cells of both the CD4+ and the CD8+ T cell population was seen shortly after treatment. Most notably, within the CD4+,CD45RA- T cell subset, the number of interferon-gamma-producing T cells was significantly increased after anti-TNFalpha mAb treatment, resulting in a significant rise in the Th1:Th2 ratio. In addition, an increase in the number of CD4+ T cells expressing the homing receptor CD49d in high density was observed after treatment, which correlated positively with the increase in the Th1:Th2 ratio. Conclusion. We show that the Th1:Th2 ratio in the peripheral blood is raised by anti-TNFalpha mAb treatment.     

Low T cell production of TNFalpha and IFNgamma in ankylosing spondylitis: its relation to HLA-B27 and influence of the TNF-308 gene polymorphism

OBJECTIVE: To test the hypothesis that ankylosing spondylitis (AS) is a T helper cell type 2 polarised disease by quantifying the T cell cytokines interferon gamma (IFNgamma), interleukin 4 (IL4), tumour necrosis factor alpha (TNFalpha), and IL10 at the single cell level in patients with AS in comparison with healthy HLA-B27 negative and HLA-B27 positive controls. METHODS: Peripheral blood mononuclear cells from 65 subjects (25 HLA-B27 positive patients with active AS, 18 healthy HLA-B27 positive controls, and 22 healthy HLA-B27 negative controls) were stimulated with phorbol myristate acetate/ionomycin for six hours, surface stained for CD3 and CD8, intracellularly stained for the cytokines IFNgamma, TNFalpha, IL4, and IL10, and analysed by flow cytometry. TNFalpha production was related to the genotype of the TNFalpha promoter at the -308 and -238 polymorphisms. RESULTS: In peripheral blood the percentage of TNFalpha+ T cells was significantly lower in HLA-B27 positive patients with AS (median 5.1% for CD4+ T cells) than in healthy HLA-B27 negative controls (median 9.5%; p=0.008). Surprisingly, the percentage of TNFalpha+ T cells was also significantly lower in healthy HLA-B27 positive controls (median 7.48%) than in healthy HLA-B27 negative controls (p=0.034). Furthermore, the percentage of IFNgamma+ T cells was lower in patients with AS and in healthy HLA-B27 positive controls than in healthy HLA-B27 negative controls (p=0.005 and p=0.003, respectively). The percentage of IL10+/CD8+ T cells was higher in patients with AS than in both control groups. In HLA-B27 positive subjects, TNF1/2 heterozygosity at -308 (n=6) was associated with a higher percentage of TNFalpha+ T cells than TNF1/1 homozygosity (n=25; median 9.97% v 5.11% for CD4+ T cells; p=0.017). In contrast, in HLA-B27 negative controls (n=18) there was no such genotype/phenotype correlation (median 9.4% v 10.6%). CONCLUSIONS: The lower T cell production of TNFalpha and IFNgamma shown at the single cell level in HLA-B27 positive patients with AS and healthy HLA-B27 positive controls may contribute to the increased susceptibility of HLA-B27 positive subjects to develop AS. Preliminary genotype-phenotype correlations suggest that in HLA-B27 positive subjects TNF2 at -308 or a linked gene results in higher TNFalpha production and, therefore, might be a marker for a protective haplotype.     

Interleukin 7 stimulates tumour necrosis factor alpha and Th1 cytokine production in joints of patients with rheumatoid arthritis

BACKGROUND: A large number of activated T cells are found in the joints of patients with rheumatoid arthritis (RA). Interleukin 7 (IL7), a T cell growth factor and a regulator of Th1 and Th2 cytokine production, is produced by synoviocytes from patients with RA. OBJECTIVE: To investigate the effect on proinflammatory cytokine production of synovial fluid mononuclear cells (SFMC) and the mechanism by which IL7 influences CD4+ T cell activity in patients with RA. METHODS: In a cross sectional group of patients with RA, IL7 levels were compared with those of healthy controls and related to disease activity. The effect of IL7 on cytokine production was tested by RA SFMC and on SF CD4+ T cells in the presence of mononuclear cells (MC). Production of tumour necrosis factor alpha (TNF alpha), IL1 beta, interferon gamma (IFN gamma), and IL4 was measured by enzyme linked immunosorbent assay (ELISA) and by single cell FACS analysis. Expression of the IL7 receptor alpha chain on CD4+ T cells (essential for IL7 signalling) was assessed. Direct effects of IL7 on isolated synovial fluid (SF) CD4+ T cells were studied by cytokine analysis. By neutralisation of IL12 in MC cultures, indirect effects of IL7 on T cells through accessory cells were studied. RESULTS: IL7 serum levels were higher in patients with RA than in healthy controls and correlated positively with C reactive protein levels. IL7 stimulated TNFalpha production by SFMC and very potently stimulated IFN gamma and TNF alpha production by SF CD4+ T cells. These effects were probably mediated through the IL7 receptor alpha chain, which was abundantly expressed on SF CD4+ T cells. Besides the direct stimulation of T cell cytokine production by IL7, its action was partly dependent on IL12, indicating that IL7 also stimulates accessory cell function, leading to T cell activation. CONCLUSION: IL7 stimulates proinflammatory cytokine production of intra-articular CD4+ T cells and accessory cells from patients with RA. The correlation with measures of disease activity indicates that IL7 might substantially contribute to the perpetuation of Th1 and TNF alpha mediated proinflammatory responses in patients with RA.     

Maintenance of T1 response as induced during PEG-IFNalpha plus ribavirin therapy controls viral replication in genotype-1 patients with chronic hepatitis C.

OBJECTIVES: To analyze the T1/T2 cytokine profile in CD8 T cells from peripheral blood mononuclear cells from patients with genotype-1 CHC during treatment with pegylated interferon (Peg-IFN) alpha2a plus ribavirin (RBV). To correlate Th1/Th2 balance with virological response. PATIENTS AND METHODS: In this prospective longitudinal study, a total of 28 na?ve genotype-1 CHC patients received Peg-IFNalpha2a (180 microg/week) plus RBV (1-1.2 g/day) for 48 weeks. All patients (mean age 45 +/- 8 years) completed treatment and follow-up: 12 (43%) achieved a sustained virological response (SVR), 13 relapsed after end of treatment (47%), and only 3 (10%) were non-responders. Sixteen healthy controls were also analyzed (mean age 39 +/- 17 years). The production of IL-4, IFNgamma, and TNFalpha by CD8 T cells was measured by intracytoplasmic detection using flow cytometry in both resting and stimulated cells with a phorbol ester. Statistics: Student's t test for independent values, chi2 test, and ANOVA test were used; relapsers and non-responders were joined to achieve a higher statistical power. RESULTS: At third month during treatment, phorbol ester-stimulated-IL-4 levels tend to be lower in patients who presented with SVR versus those who did not (0.97 vs 2.58; p = 0.1). No statistically significant differences were found in IFNgamma and TNFalpha levels at month 3. At EOT, the stimulated-IFNgamma production was significantly higher in patients with SVR (20 vs. 8; p < 0.05). Conversely, IL-4 production was higher in NR patients although these data did not reach statistical significance (p < 0.1). No significant differences were found in TNFalpha (14 vs. 7; p < 0.2). CONCLUSIONS: Cytokine T1 induced-response maintenance during combination treatment, measured as IFNgamma production by CD8+ T lymphocytes, is associated with SVR and suggests the replication control and later clearance of patients infected by genotype-1 HCV.     

Response to methotrexate in early rheumatoid arthritis is associated with a decrease of T cell derived tumour necrosis factor alpha, increase of interleukin 10, and predicted by the initial concentration of interleukin 4

OBJECTIVE: This study was performed to assess whether there is any change in the T cell cytokine pattern in early rheumatoid arthritis (RA) patients treated with methotrexate (MTX) and whether the lymphocytic cytokine pattern correlates with disease activity. METHODS: Eight patients with RA (disease duration < six months) were studied serially before, after three, and after six to nine months of treatment with MTX for the cytokines tumour necrosis factor alpha (TNFalpha), interferon gamma (IFNgamma), interleukin 4 (IL4) and interleukin 10 (IL10) by intracellular staining of T cells derived from peripheral blood. Response to treatment was assessed by the modified disease activitiy score. RESULTS: The clincial response was accompanied by a significant decrease of TNFalpha positive CD4(+) T cells from a median of 8.53% (interquartile range 5.83-10.91%) before treatment to 6.17% (2.15-6.81%) after six to nine months of treatment (p=0.021). Inversely, IL10 positive T cells increased from a median of 0.65% (interquartile range 0.6-0.93%) to a median of 1. 3% (1.22%-1.58%) after six to nine months of treatment (p=0.009). No significant change in the percentage of INFgamma positive T cells and a small decrease of IL4 positive T cells during treatment were observed. The percentage of IL4 positive CD4(+) T cells before treatment correlated with disease activity after six to nine months (r= -0.7066; p=0.05). CONCLUSIONS: During treatment of RA with MTX the percentage of TNFalpha producing T cells decreases whereas that of IL10 producing T cells increases. This may affect macrophage activation and, therefore, may represent a regulatory mechanism relevant to disease remission. Furthermore, the percentage of IL4 positive CD4(+) T cells at disease onset may be a useful prognostic marker.     

Persistence of interleukin 7 activity and levels on tumour necrosis factor alpha blockade in patients with rheumatoid arthritis

OBJECTIVES: To identify the mechanism of interleukin (IL)7-stimulated tumour necrosis factor alpha (TNFalpha) production and to determine the relationship between intra-articular IL7 and TNFalpha expression levels in patients with rheumatoid arthritis (RA). In addition, the effect of TNFalpha blockade on IL7 activity and on IL7 levels was studied. METHODS: The effect of IL7 on isolated CD4 T cells and CD14 monocytes/macrophages was studied. IL7 and TNFalpha levels were measured in the synovial fluid of patients with RA. In RA synovial tissue, IL7 and TNFalpha expression was assessed in addition to IL1beta, numbers of inflammatory cells and adhesion molecule expression. The extent to which TNFalpha blockade could prevent IL7-induced lymphocyte responses was studied in vitro. In addition, regulation of serum IL7 levels on anti-TNFalpha therapy (adalimumab) was studied. RESULTS: IL7 induced cell contact-dependent TNFalpha production by cocultures of T cells and monocytes, but not by T cells and monocytes cultured separately. IL7 and TNFalpha levels in RA synovial fluid and synovial tissue significantly correlated. IL7-stimulated lymphocyte responses were not inhibited by TNFalpha blockade. Circulating IL7 levels were significantly reduced in patients who successfully responded to anti-TNFalpha treatment. However, IL7 levels persisted in non-responders. CONCLUSION: The present data suggest that IL7 is an important inducer of T cell-dependent TNFalpha production in RA joints. This may contribute to the correlation of intra-articular IL7 and TNFalpha in these joints. Furthermore, the persistence of IL7-induced inflammatory activity on TNFalpha blockade in vitro and persistence of IL7 levels and disease activity in anti-TNFalpha non-responders suggest that IL7 might additionally promote TNFalpha-independent inflammation.     

Analysis of Th1 and Th2 cytokines expressing CD4+ and CD8+ T cells in rheumatoid arthritis by flow cytometry

OBJECTIVE: A Th1/Th2 cytokine imbalance with a predominance of Th1 cytokines has been suggested to be of pathogenetic importance in rheumatoid arthritis (RA). To evaluate the role of Th1/Th2 cytokines in RA, we used intracellular cytokine flow cytometry to determine cytokine profiles of CD4+ and CD8+ T cells in 34 peripheral blood (PB) and 10 synovial fluid (SF) samples from patients with RA. Results were compared with 10 PB samples from healthy controls (HC) and 5 SF samples from patients with non-RA synovitis. METHODS: After stimulating cells with PMA and ionomycin or alternatively with anti-CD3/CD28 in the presence of brefeldin A, intracellular levels of Th1 [interleukin 2 (IL-2), interferon-gamma (IFN-gamma)] and Th2 cytokines (IL-4, IL-5, IL-10, IL-13) were determined for CD3+CD8- (i.e., CD4+ Th1 and Th2 cells) and CD3+CD8+ (i.e., CD8+ Tc1 and Tc2 cells) T cells. RESULTS: The percentages of CD4+ and CD8+ Th1 and Th2 cytokines producing T cells (PB) were similar in patients with RA and healthy controls (HC), with a clear predominance of Th1 cytokines expressing, T cells. With regard to T cell subsets, IFN-gamma-producing T cells were significantly more frequently detected in the CD8+ subset [CD8+: median 45.1% (RA; p < 0.001), 38.2% (HC; p = 0.009) vs CD4+: 10.8%(RA), 17.0% (HC)]. Conversely, IL-2 was found in a higher percentage of CD4+ T cells [CD4+: median 33.4% (RA), 17.9% (HC) vs CD8+: 23.6% (RA), 12.3% (HC)]. Patients not in disease remission tended to have more IFN-gamma-producing CD8+ and IL-2-producing CD4+ T cells than patients in remission [CD8+: median 45.9% (IFN-gamma) vs 23.0% (IFN-gamma); CD4+: median 34.1% (IL-2) vs 18.2% (IL-2)1. In all PB samples, the proportion of T cells producing the Th2 cytokines IL-4, IL-5, IL-10, and IL-13 did not exceed 2%. Cytokine profiles did not differ between patients receiving immunosuppressive treatment and patients treated only with nonsteroidal antiinflammatory drugs. In comparison to PB, RA SF analysis revealed a significant increase in the percentage of IFN-gamma-producing CD4+ (p < 0.001) and CD8+ T cells (p < 0.001). In addition, the percentage of IL-10-producing CD4+ (p < 0.001) as well as CD8+ T cells (p = 0.001) was significantly elevated in SF. However, production of the other Th2 cytokines (IL-4, IL-5, IL-13) was similar in SF and PB. CONCLUSION: These data indicate similar cytokine profiles of T cells in PB of RA patients and healthy controls, with a strong predominance of Th1 cytokines producing T cells in the CD4+ and CD8+ T cell subset of both groups. PB cytokine profiles did not significantly differ in patients with active and non-active disease or between patients receiving and those not receiving immunosuppressive medication. In SF, the proportion of Th1 and Tcl cells was significantly elevated compared to PB, emphasizing the local importance of these cells for inflammation. CD8+ T cells (Tc1 cells) mainly contributed to the production of IFN-gamma, indicating an underestimated role of this cell subset for local cytokine production. The upregulation of IL-10-producing Th2 and Tc2 cells in SF may reflect an insufficient effort to down-regulate chronic inflammation in the joint. Modifying this cytokine imbalance in the joints may be a promising therapeutic approach in RA.     

Tumor necrosis factor alpha blockade treatment down-modulates the increased systemic and local expression of Toll-like receptor 2 and Toll-like receptor 4 in spondylarthropathy

OBJECTIVE: Abnormal host defense against pathogens has been implicated in the pathogenesis of spondylarthropathy (SpA), a disease characterized by abundant synovial infiltration with innate immune cells. Given the role of Toll-like receptors (TLRs) in activation of innate inflammation and the occurrence of TLR-dependent infections after tumor necrosis factor alpha (TNFalpha) blockade treatment, the present study was undertaken to analyze TLRs and their modulation by TNFalpha blockade in SpA. METHODS: Peripheral blood mononuclear cells (PBMCs) were obtained from SpA and rheumatoid arthritis (RA) patients during infliximab therapy, and from healthy controls. TLR-2 and TLR-4 expression and TNFalpha production upon lipopolysaccharide (LPS) stimulation were analyzed by flow cytometry on different monocyte subsets. Synovial biopsy specimens from 23 SpA patients before and after infliximab or etanercept treatment, from 15 RA patients, and from 18 osteoarthritis (OA) patients were analyzed by immunohistochemistry. RESULTS: Expression of TLR-4, but not TLR-2, was increased on PBMCs from patients with SpA, whereas both TLRs were increased in RA patients. TLR expression was particularly increased on the CD163+ macrophage subset. Infliximab reduced TLR-2 and TLR-4 expression on monocytes of SpA and RA patients, leading to lower levels than in controls and to impaired TNFalpha production upon LPS stimulation. In inflamed synovium, the expression of both TLRs and of CD163 was significantly higher in patients with SpA than in those with RA or OA. Paralleling the systemic effect, TLRs in synovium were down-regulated following treatment with infliximab as well as etanercept, indicating a class effect of TNFalpha blockers. CONCLUSION: Inflammation in SpA is characterized by increased TLR-2 and TLR-4 expression, which is sharply reduced by TNFalpha blockade. These findings suggest a potential role of innate immunity-mediated inflammation in SpA and provide an additional clue regarding the mechanism of action as well as the potential side effects of TNFalpha blockade.     

Increased peripheral T cell reactivity to microbial antigens and collagen type II in rheumatoid arthritis after treatment with soluble TNFalpha receptors

OBJECTIVE: Peripheral T cells from patients with rheumatoid arthritis (RA) are hyporesponsive when stimulated with antigen or mitogen in vitro, possibly owing to increased production of proinflammatory cytokines such as tumour necrosis factor alpha (TNFalpha). This study sought to find out if and how RA T cell reactivity is affected during treatment with etanercept (Enbrel), a soluble TNFalpha receptor. METHODS: Heparinised blood was collected from patients with RA at baseline, after four and eight weeks of etanercept treatment, and from healthy controls. After density separation spontaneous production of interferon gamma (IFNgamma), TNFalpha, interleukin 6 (IL6), and IL10 by peripheral blood mononuclear cells (PBMC) was detected by ELISPOT. For detection of T cell reactivity, PBMC were stimulated in vitro with mitogen (phytohaemagglutinin (PHA)), microbial antigens (purified protein derivative (PPD), influenza), or an autoantigen, collagen type II (CII). Supernatants were analysed for IFNgamma and IL2 content by enzyme linked immunosorbent assay (ELISA). RESULTS: In RA the number of cells spontaneously producing IFNgamma was significantly increased after four, but not eight weeks' treatment with etanercept. T cell reactivity, as measured by IFNgamma production to PPD, influenza, and CII was significantly increased after four and sustained after eight weeks' treatment, whereas IFNgamma production induced by PHA remained unchanged. TNFalpha production was significantly higher in patients with RA than in controls and did not change during etanercept treatment. CONCLUSION: Treatment of patients with RA with etanercept may lead to increased peripheral T cell reactivity both to microbial antigens and to self antigens such as CII. These findings indicate that TNFalpha blockade may not only suppress but also stimulate certain aspects of antimicrobial immune defence and autoimmunity.     

Anti-tumour necrosis factor (TNF) alpha treatment of rheumatoid arthritis (infliximab) selectively down regulates the production of interleukin (IL) 18 but not of IL12 and IL13

OBJECTIVE: To measure interleukin (IL)18 serum concentrations in patients with rheumatoid arthritis (RA) undergoing infliximab treatment (tumour necrosis factor (TNF) alpha blockade) and to evaluate the concomitant modification of IL12 and IL13 serum concentrations, two cytokines belonging to the Th1 and Th2 profile respectively and biologically related to IL18. METHODS: Ten patients with RA not responding to disease modifying antirheumatic drugs (DMARDs) received intravenous infliximab at a dose of 3 mg/kg at baseline and after two and six weeks. Serum samples were collected from all patients before each infusion and assayed for IL18, IL12, and IL13 by enzyme linked immunosorbent assay (ELISA); IL18 was also measured eight weeks after the last infusion. RESULTS: Serum concentrations of IL18 in all patients were already markedly reduced from baseline after two weeks (p<0.005). Serum IL18 was also decreased in a stable manner after six (p<0.01) and 14 weeks (p<0.01) compared with baseline concentrations. No significant modifications were found in serum concentrations of IL12 and IL13 at any time point. CONCLUSION: There was a rapid and persistent decrease in serum concentrations of IL18 in all the patients studied. This result provides evidence of an in vivo regulation of IL18 by TNFalpha and suggests that anti-TNFalpha therapy is likely to interrupt the synergistic effect between these two cytokines.     

Altered cytokine expression of peripheral blood lymphocytes in polymyositis and dermatomyositis

OBJECTIVE: To investigate the intracellular and soluble cytokine levels and T cell subsets in peripheral blood of patients with active and inactive polymyositis and dermatomyositis. METHODS: The frequencies of T and B lymphocytes, T helper (Th), and T cytotoxic (Tc) cells and of interferon gamma (IFNgamma), interleukin (IL)4, and IL10 expression of CD4+ or CD8+ cells were determined by flow cytometry. The concentrations of soluble cytokines were measured with commercial enzyme linked immunosorbent assays. RESULTS: In active dermatomyositis there was a decreased percentage of T (CD3+) lymphocytes and Tc (CD8+) lymphocytes, decreased IFNgamma expression of CD4+ and CD8+ cells, but an increase in B and IL4 producing CD4+ lymphocyte frequencies. These prominent changes disappeared in the inactive stage of the disease. In polymyositis no significant change in these lymphocyte subsets or in intracellular cytokine expression could be detected in either the active or the inactive form. The frequency of IL4+/IFNgamma+ Th cells was calculated and a significantly increased Th2/Th1 frequency was found in active dermatomyositis, and a decreased frequency in inactive dermatomyositis, compared with the control population. CONCLUSIONS: There appears to be a difference between polymyositis and dermatomyositis in the level of peripheral blood lymphocytes and their intracellular cytokine content. These findings provide further evidence for a difference in the pathogenesis of polymyositis and dermatomyositis.     

A novel role for interleukin-18 in human natural killer cell death: high serum levels and low natural killer cell numbers in patients with systemic autoimmune diseases

OBJECTIVE: Patients with systemic autoimmune diseases have been reported to have reduced numbers of peripheral blood natural killer (NK) cells compared with healthy subjects. The ability of selected cytokines to trigger NK cell death prompted us to compare the levels of peripheral blood cytokines with the numbers of NK cells in patients with various systemic autoimmune diseases. METHODS: We used enzyme-linked immunosorbent assays to measure the concentration of selected cytokines (interleukin-18 [IL-18], IL-15, IL-12, IL-2, interferon-gamma [IFNgamma], and tumor necrosis factor alpha [TNFalpha]) in sera from 58 patients with systemic autoimmune diseases and 33 healthy controls. The absolute number of T cells and NK cells in the peripheral blood was measured in parallel using flow cytometry. The ability of selected cytokines to induce NK cell death was then measured using 3,3'-dihexyloxacarbocyanine iodide dye, propidium iodide staining, and caspase 3 activity. RESULTS: Levels of IL-18, IL-15, IFNgamma, and TNFalpha were elevated in sera from patients with systemic autoimmune diseases compared with normal controls. The percentage of NK cells and natural killer T cells were significantly decreased in the peripheral blood of patients with systemic autoimmune diseases compared with normal controls. Serum concentrations of IL-18, IL-15, and TNFalpha were inversely related to the number of NK cells in both patients and healthy controls. The combination of IL-18 and IL-15 or IL-18 and IL-12 induced NK cell death in vitro. The combination of IL-18 and IL-15 or IL-18 and IL-12 enhanced IFNgamma and TNFalpha production by NK cells in vitro. Cytokine-induced NK cell death is caspase-dependent and is partially blocked by neutralizing antibodies against TNFalpha. CONCLUSION: High levels of IL-18 and IL-15 are associated with the decreased number of NK cells that is observed in patients with systemic autoimmune diseases.     

Peripheral T lymphocyte cytokine profile (IFNgamma, IL-2, IL-4) and CD30 expression/release during measles infection.

BACKGROUND AND OBJECTIVE: Measles virus infection (MVI) has been reported to be characterized by an imbalanced Th(1/2)-type cytokine profile. CD30 has been proposed as a receptor preferentially associated with the Th(0/2)-type cytokine pattern. The aim of this study was therefore to define the peripheral T lymphocyte cytokine profile and to test which CD30 expression pattern it was associated with in MVI. DESIGN AND METHODS: The design of the study was a prospective evaluation with comparative analysis. The serum levels of the soluble form of CD30 (sCD30) were determined at diagnosis and at weekly intervals up to 4 weeks, using an ELISA, in 23 males (median age 19), who developed MVI while serving in the Italian army and who were admitted to the Infectious Disease Unit of the Military Hospital in Padua. In 10 of the patients at diagnosis we studied the lymphoid immunophenotype and, after non-specific ex vivo stimulation, the expression of IFNgamma, IL-2 and IL-4 by peripheral T cells using flow cytometry single cell analysis. In 3 patients such evaluations were also performed 7 weeks later. RESULTS: At diagnosis, we found (i) reduction of IFNgamma+/CD4+ T cells (p=0.048 vs controls) in the absence of substantial variation of IL-2+ and IL-4+ T cells (p=ns vs controls); (ii) expansion of CD30+/ CD4+ and CD30+/CD8+ T cell subsets (p<0.01 vs controls); (iii) high sCD30 values (median 61 U/mL; p<0.001 vs controls); (iiii) a context of lymphopenia (0. 728+/-0.292 lymph x10(9)/L). sCD30 remained elevated up to 4 weeks from MVI onset [median values 53, 49, 50, 34 U/mL after 1, 2, 3 and 4 weeks, respectively (p=ns between different time points)]. In 3 patients tested 7 weeks after diagnosis, we still observed decreased IFNgamma production by CD4+ and CD8+ T cells (p=0.05 and <0.01, respectively vs controls) and reduction of CD4+ and CD8+/IL-2+ T cells (p<0.01). INTERPRETATION AND CONCLUSIONS: MVI was characterized by featuresof inadequate Th/Tc(1) activation associated with increased circulating CD30+ T cells and elevated sCD30 levels, supporting a correlation between Th/Tc status and CD30 expression/release pattern in vivo.     

Immunological alterations in newly diagnosed primary Sjögren's syndrome characterized by skewed peripheral T-cell subsets and inflammatory cytokines

OBJECTIVES: To describe how certain peripheral immune parameters reflect the inflammatory alterations in patients with primary Sj?gren's syndrome (pSS). We determined lymphocyte subpopulations and their state of activation from peripheral blood, evaluating both soluble serum T-helper (Th)1/Th2-type cytokines and intracytoplasmic cytokines. METHODS: Forty-nine patients with newly diagnosed pSS and 40 healthy individuals, all free from immunomodulant or immunosuppressive medication, were studied. Peripheral blood lymphocyte subgroups were quantified by flow cytometry, soluble cytokines were assessed using enzyme-linked immunosorbent assay (ELISA), and intracellular cytokine levels were measured after phorbol myristate acetate (PMA) stimulation by flow cytometry after staining of intracellular cytokines. RESULTS: Patients with primary SS had higher percentages of activated CD3+/CD69+ T cells than controls. When comparing na?ve vs. memory subsets of CD4+ and CD8+ T cells, a shift towards the memory phenotype was observed for both. Natural killer (NK) cell and NK T-cell (NKT) percentages and Th0 and Th1 cell numbers were increased in patients compared to controls. Among circulating cytokines, interferon (IFN)-gamma was high, whereas interleukin (IL)-10 was decreased in SS when compared to controls. CONCLUSIONS: SS, considered as a systemic autoimmune disease, is characterized by a complex interplay of various cytokines and immune cells. The skewed T-cell subsets and cytokine imbalance play important roles in an orchestrated proinflammatory cascade.