Study of pro-inflammatory (TNF-alpha, IL-1alpha, IL-6) and T-cell-derived (IL-2, IL-4) cytokines in plasma and synovial fluid of patients with juvenile chronic arthritis: correlations with clinical and laboratory parameters

Cytokine profiling and in vitro studies of murine bone growth using biological fluids from children with juvenile idiopathic arthritis

OBJECTIVE

Growth retardation in children with chronic inflammatory disease may be partly due to direct effects of pro-inflammatory cytokines on the growth plate and requires further investigation.

DESIGN

This study assessed the cytokine concentrations in serum and synovial fluid (SF) in juvenile idiopathic arthritis (JIA), and determined the effect of the biological fluid on cultured murine metatarsal growth.

PATIENTS

Serum and SF were obtained from four children attending for arthrocentesis (child A, systemic; children B, C and D, oligoarticular). In addition, serum samples were obtained from four more children (children E and F, polyarticular; child G, oligoarticular).

MEASUREMENTS

Anthropometry, cytokine levels and longitudinal bone growth were assessed.

RESULTS

Cytokines were elevated to a variable extent in the samples. Although all serum samples were associated with reduced metatarsal growth, only SF from child A and child B reduced metatarsal growth. Metatarsals treated with child A's SF showed reduced proliferation, reduced proliferative and mineralizing zone width, and increased hypertrophic zone width. Tumour necrosis factor (TNF)-alpha, interleukin (IL)-1beta and IL-6 concentrations were elevated in child A's SF. However, SF exposure with neutralizing antibodies to these cytokines or IGF-1 did not improve metatarsal growth.

CONCLUSION

SF and serum JIA samples can impair bone growth at the growth plate. In synovial fluid, the effect is variable but resistant to treatment with IL-1beta, IL-6 and TNF-alpha specific antibodies and IGF-1, suggesting that other factors in this biological fluid may also have an effect on longitudinal growth through IGF-1-independent mechanisms.

Immune activation in patients with irritable bowel syndrome

BACKGROUND AND AIMS

We set out to test the hypothesis that irritable bowel syndrome (IBS) is characterized by an augmented cellular immune response with enhanced production of proinflammatory cytokines. We further aimed to explore whether symptoms and psychiatric comorbidity in IBS are linked to the release of proinflammatory cytokines.

METHODS

We characterized basal and Escherichia coli lipopolysaccharide (LPS)-induced cytokine production in peripheral blood mononuclear cells (PBMCs) from 55 IBS patients (18 mixed-, 17 constipation-, 20 diarrhea-predominant) and 36 healthy controls (HCs). PBMCs were isolated by density gradient centrifugation and cultured for 24 hours with or without (1 ng/mL) LPS. Cytokine production (tumor necrosis factor [TNF]-alpha, interleukin [IL]-1beta, and IL-6) was measured by enzyme-linked immunosorbent assay. Abdominal symptoms and psychiatric comorbidities were assessed by using the validated Bowel Disease Questionnaire and the Hospital Anxiety and Depression Scale.

RESULTS

IBS patients showed significantly (P < .017) higher baseline TNF-alpha, IL-1beta, IL-6, and LPS-induced IL-6 levels compared with HCs. Analyzing IBS subgroups, all cytokine levels were significantly (P < .05) higher in diarrhea-predominant IBS (D-IBS) patients, whereas constipation-predominant IBS patients showed increased LPS-induced IL-1beta levels compared with HCs. Baseline TNF-alpha and LPS-induced TNF-alpha and IL-6 levels were significantly higher in patients reporting more than 3 bowel movements per day, urgency, watery stools, and pain associated with diarrhea compared with patients without these symptoms (all P < .05). LPS-induced TNF-alpha production was associated significantly (r = 0.59, P < .001) with anxiety in patients with IBS.

CONCLUSIONS

Patients with D-IBS display enhanced proinflammatory cytokine release, and this may be associated with symptoms and anxiety.

Blood and synovial fluid cytokine signatures in patients with juvenile idiopathic arthritis: a cross-sectional study

BACKGROUND

Juvenile idiopathic arthritis (JIA) consists of a heterogeneous group of disorders with, for the most part, an unknown immunopathogenesis. Although onset and disease course differ, the subtypes of JIA share the occurrence of chronic inflammation of the joints, with infiltrations of immunocompetent cells that secrete inflammatory mediators.

OBJECTIVE

To identify a panel of cytokines specifically related to the inflammatory process in JIA.

METHODS

Using a new technology, the multiplex immunoassay, 30 cytokines were measured in plasma of 65 patients with JIA, of which 34 were paired with synovial fluid. These data were compared with plasma of 20 healthy controls and 9 patients with type I diabetes, a chronic inflammatory disease.

RESULTS

Patients with JIA had, irrespective of their subclassification, significantly higher levels of tumour necrosis factor alpha, macrophage inhibitory factor (MIF), CCL2, CCL3, CCL11, CCL22 and CXCL9 in plasma than controls. In paired plasma and synovial fluid samples of patients with JIA, significantly higher levels of interleukin (IL)6, IL15, CCL2, CCL3, CXCL8, CXCL9 and CXCL10 were present in synovial fluid. Cluster analysis in all patients with JIA revealed a predominant pro-inflammatory cytokine cluster during active disease and a regulatory/anti-inflammatory-related cytokine cluster during remission. Whether a discrimination profile of various cytokines could help in the determination of disease classification was tested.

CONCLUSION

It is suggested that several cytokines (IL18, MIF, CCL2, CCL3, CCL11, CXCL9 and CXCL10) may correspond to the activation status during inflammation in JIA and could be instrumental in monitoring disease activity and outcomes of (new) immunotherapies.

Markers for sepsis diagnosis: what is useful?

Timely diagnosis of the different severities of septic inflammation is potentially lifesaving because therapies that have been shown to lower mortality should be initiated early. Sepsis and severe sepsis are accompanied by clinical and laboratory signs of systemic inflammation but patients with inflammation caused by noninfectious causes may present with similar signs and symptoms. It is important to identify markers for an early diagnosis of sepsis and organ dysfunction. This article presents currently interesting sepsis biomarkers. Other novel markers and their potential role are discussed.

Allelic frequency of the MCP-1 promoter −2518 polymorphism in the Turkish population and in Turkish patients with juvenile rheumatoid arthritis

Although genetic and environmental factors contribute to the pathogenesis of juvenile rheumathoid arthritis (JRA), the etiology and pathogenesis remain controversial. The objective of this study was to investigate genotypic and allelic frequencies of monocyte chemoattractant protein-1 (MCP-1) gene -2518 (G/A) polymorphism in the healthy Turkish population and patients with JRA. Genomic DNA was collected from 66 JRA patients and 150 healthy individuals. To evaluate the association of the -2518 (G/A) MCP-1 gene polymorphism with the outcome of JRA, we analyzed the types of JRA and the score on the childhood health assessment questionnaire (C-HAQ score). In the healthy Turkish population, the frequencies of A and G alleles were 71 and 29%, respectively. No significant difference was observed between the JRA patients and healthy subjects in the distribution allelic and genotypic frequencies of the -2518 (G/A) MCP-1 gene polymorphism (p>0.05). However, the AG genotype was found to be higher and the AA genotype was found to be lower in the patients with systemic type JRA compared to those with the other types of JRA (p=0.019). When the JRA patients were evaluated according to the C-HAQ score, we found that the -2518 (G/A) MCP-1 gene polymorphism did not relate the prognosis (p>0.05). AG genotype was found to be higher in the systemic type of JRA. The results indicate that MCP-1 gene polymorphism might slightly associate with patients with systemic JRA. Further studies are needed to elucidate the role of this polymorphism in the pathogenesis of JRA in various populations because this polymorphism has a functional significance and an ethnic difference.

The use of anakinra in juvenile arthritis

Interleukin-1 (IL-1), one of the major pro-inflammatory cytokines, plays an important role in the pathophysiology and progression of adult and pediatric arthritis. Inhibiting IL-1 activity by using a recombinant human IL-1 receptor antagonist (anakinra) given alone or in combination with methotrexate, moderately reduced the signs and symptoms of active arthritis in adults and slowed the rate of radiographic destruction. Preliminary results from an open label portion of a trial in children with polyarticular arthritis show similar outcomes with 58% of children exhibiting clinical improvements based on the Juvenile Arthritis 30% Core Set Criteria. The drug has an overall favorable safety profile and injection-site reactions are the most commonly reported adverse event in both groups. However despite its rather disappointing effect in polyarticular arthritis, anakinra is being discovered as an effective treatment of systemic arthritis and children with mutations in the NALP3/CIAS1/PYPAF1 genes leading to autoimmune inflammatory disorders such as neonatal- onset multisystem inflammatory disease.

Juvenile idiopathic arthritis

One of the most enigmatic problems in rheumatology has been juvenile idiopathic arthritis (JIA). Firstly, the classification has often depended on clinical features that have variations between patients. Secondly, there are different classification schemes in usage and there are few objective serologic tests that help to resolve the differences between the criteria sets. Thirdly, only recently have significant advances been made in understanding the immunology and immunopathology of JIA and, in particular, new treatment options. In this review, we will define the historical basis of JIA and emphasize not only the clinical features, but also the immunological characteristics, the pathogenesis, and treatment options. We will also discuss, in particular, quality of life, psychosocial functioning, socioeconomic outcomes and the difficult area of mortality. Finally, this review will attempt to bridge genetic observations with clinical presentation. JIA represents a relatively common syndrome of pediatric onset rheumatologic disease and a better understanding of the clinical definition, the relationship to autoimmunity, and novel treatments with biologic agents are critical for improved patient care.

The pathophysiology of the growth plate in juvenile idiopathic arthritis

Children with chronic inflammatory diseases, such as juvenile idiopathic arthritis (JIA), suffer from a variety of growth disorders. These range from general growth retardation to local acceleration of growth in the affected limb. These disorders are associated with the increased production of proinflammatory cytokines, which may influence growth through a local effect in the growth plates of long bones and/or systemic effects throughout the whole body. In this article we review these aspects and also discuss the evidence for interaction between the inflammatory cytokine and growth-signalling pathways.

Cytokine genotypes correlate with pain and radiologically defined joint damage in patients with juvenile rheumatoid arthritis

OBJECTIVES

Single nucleotide polymorphisms (SNPs) in cytokine genes have been associated with risk of a number of autoimmune diseases. Moreover, some SNPs are associated with variations in rates of in vitro gene expression, and it is therefore possible that these functional polymorphisms may differentially affect inflammatory processes and disease outcome. This project's objective was to determine whether cytokine genotypes correlate with disease outcomes in patients with juvenile rheumatoid arthritis (JRA).

METHODS

Genotypes of SNPs of pro-inflammatory cytokines, tumour necrosis factor-alpha -308G -->A, interleukin-6 (IL-6) -174G -->C and interferon-gamma +874G -->A, and anti-inflammatory, immunosuppressive cytokines, interleukin-10 -1082G -->A, -819C -->T and -592A -->C and transforming growth factor-beta1 (TGF-beta1) codon 10T -->C and codon 25G -->C, were determined for patients with JRA who previously participated in a long-term outcome study. Cytokine genotypes and clinical variables showing significant correlations with clinical outcomes at the alpha = 0.100 level in univariate analyses were entered in multivariate tests.

RESULTS

In multivariate tests, the IL-6 genotype -174G/G was positively correlated with pain [regression coefficient B = 0.899, 95% confidence intervals (CI) 0.185, 1.612, P = 0.014]. The homozygous TGF-beta1 codon 25G/G genotype showed a protective effect against joint space narrowing on radiographs taken within 2 yr of disease onset, but confidence intervals were wide [odds ratio (OR) 0.176, 95% CI 0.037, 0.837 P = 0.029].

CONCLUSIONS

The correlation of IL-6 genotype with pain and the possible association of the TGF-beta1 codon 25 genotype with short-term radiographic damage (G/C with greater risk and G/G with decreased risk) suggests that both these polymorphisms may be useful early prognostic indicators. Further studies of the relation between cytokine genotypes and outcomes in patients with all forms of juvenile idiopathic arthritis (JIA) are warranted.

Developments in the treatment of juvenile arthritis

Although rarely a life-threatening disease, juvenile arthritis (JA) can, if poorly controlled, profoundly affect growth, development and quality of life in children. Long-term damage in children with JA rarely arises from overly aggressive therapy, but rather from an overly conservative and cautious approach in the early stages of the disease. As more potential therapeutic agents for JA become available, the physician must become skilled in viewing the data with a critical eye with regard to safety and efficacy in the paediatric population. The following review discusses the prognosis and management of JA, with a focus on new emerging agents for the treatment of this disease.

High-producer interleukin-2 genotype increases risk for acute graft-versus-host disease after unrelated donor bone marrow transplantation

BACKGROUND

Cytokine polymorphisms may modulate immunologic reactivity, including graft-versus-host disease (GVHD). A single nucleotide polymorphism resulting in a thymine-to-guanine transition in the interleukin (IL)-2 gene promoter region occurs at position -330. In vitro studies have shown that the G allele is associated with early and sustained enhancement of IL-2 production, a so-called high-producer genotype. Because IL-2 is a proinflammatory cytokine, we hypothesized that recipients with high-producer genotypes would have increased frequency of GVHD after allogeneic bone marrow transplantation (BMT).

METHODS

We studied 95 consecutive donor and recipient pairs who received an unrelated donor BMT at the University of Minnesota. The median age at time of BMT was 14.1 years (range 0.9-54.8 years). Stem cells were human leukocyte antigen-A, B, and DRB1 matched in 70 cases (74%) and single-antigen mismatched in 25 cases (26%). GVHD prophylaxis consisted of cyclosporine-containing regimens (53%), T-cell depletion by elutriation (42%), and others (2%).

RESULTS

The probability of grade II-IV acute GVHD at day 100 was 36% (95% confidence interval 26%-46%) and was significantly affected by the presence of recipient IL-2 G allele. The probability of acute GVHD was 49% in 49 patients (52%) with at least one G allele compared with 24% in 42 patients (44%) with no G allele (P<0.01). In the Cox regression analysis, the presence of at least one IL-2 G allele was associated with a twofold increased risk of acute GVHD.

CONCLUSIONS

If confirmed by others, our results indicate that more intensive GVHD prophylaxis is needed for patients with at least one IL-2 G allele, possibly directed toward blunting early host cell production of IL-2.

C-reactive protein (CRP) as tumor marker in pediatric and adolescent patients with Hodgkin disease

BACKGROUND

C-reactive protein (CRP) is an acute phase protein produced in the liver. An elevated CRP is a nonspecific marker of inflammation. Additionally, it also appears to be a prognostic marker in several malignancies. Elevated CRP levels in adult patients with Hodgkin disease (HD) were reported previously. However, levels of CRP have not been evaluated in pediatric and adolescent HD patients.

PROCEDURE

We analyzed CRP serum levels in 95 consecutive pediatric and adolescent patients with Hodgkin disease. CRP levels were correlated with stage, absence or presence of B symptoms, and prognosis.

RESULTS

At the time of diagnosis increased serum CRP levels were found in 64 % (61/95) of the patients with a median of 21 mg/L (range: <5-211). Serum C-reactive protein levels correlated with stage and were higher in patients with B symptoms. Higher CRP levels were associated with an increased risk of relapse.

CONCLUSION

In addition to soluble interleukin 2 receptor (sIL-2R) levels, CRP holds promise as a diagnostic and prognostic index and follow-up monitor in pediatric and adolescent patients with Hodgkin disease, and merits further investigation.

Etanercept: an updated review of its use in rheumatoid arthritis, psoriatic arthritis and juvenile rheumatoid arthritis

Etanercept is a subcutaneously administered biological response modifier that binds and inactivates tumour necrosis factor-alpha, a proinflammatory cytokine. In patients with early active rheumatoid arthritis, etanercept 25mg twice weekly was associated with a more rapid improvement in disease activity and a significantly greater cumulative response than methotrexate over 12 months of treatment in a randomised, double-blind trial. In addition, etanercept recipients showed a slower rate of radiographic progression and a more rapid improvement in quality of life than methotrexate recipients. The efficacy of etanercept was maintained at 3 years' follow-up. Etanercept was also significantly better than placebo at reducing disease activity in patients who had an inadequate response to previous treatment with disease-modifying antirheumatic drugs (DMARDs) in several well controlled trials. At study end (after 3 or 6 months' treatment), the percentage of patients achieving an American College of Rheumatology 20% (ACR20) response with etanercept (25mg or 16 mg/m(2) twice weekly) was 59 to 75% as monotherapy and 71% in combination with methotrexate; corresponding placebo response rates were 11 to 14% and 27%, respectively. Response has been maintained in patients who continued treatment for up to 5 years. In patients with psoriatic arthritis, etanercept 25mg twice weekly significantly reduced disease activity and improved skin lesions in two double-blind, placebo-controlled, 12- to 24-week trials. In the 24-week study, ACR20 response rates (50 vs 13%), psoriatic arthritis response rates (70 vs 23%) and the median improvement in skin lesions (33 vs 0%) were significantly greater in etanercept than in placebo recipients. In patients with polyarticular-course juvenile rheumatoid arthritis, etanercept resulted in improvements in all measures of disease activity and was significantly more effective than placebo at reducing disease flare. Eighty percent of patients receiving etanercept achieved a >or=30% reduction in disease activity over 7 months of treatment, and this was maintained for up to 2 years in a trial extension. Etanercept was generally well tolerated in children and adults in clinical trials; the most commonly occurring adverse effects included injection site reactions, infection, headache, rhinitis and dizziness. In conclusion, etanercept has emerged as an important new treatment option in inflammatory arthritis. Etanercept provides rapid and sustained improvements in disease activity in patients with early and DMARD-refractory rheumatoid arthritis and has been shown to inhibit radiographic progression in those with early disease. Well controlled studies have also demonstrated the efficacy of etanercept in patients with psoriatic arthritis or polyarticular-course juvenile rheumatoid arthritis.

Linkage and association studies of single-nucleotide polymorphism-tagged tumor necrosis factor haplotypes in juvenile oligoarthritis

OBJECTIVE

The presence of increased levels of tumor necrosis factor (TNF) in serum and synovial fluid of patients and the encouraging outcome of anti-TNF therapy have implicated TNFalpha in the etiopathogenesis of juvenile oligoarthritis. Although the locus is polymorphic, no study has investigated all TNF single-nucleotide polymorphisms (SNPs) with respect to disease. The aim of this study was to examine the association of multiple TNF SNPs with juvenile oligoarthritis and to construct and analyze SNP-tagged TNF haplotypes.

METHODS

A total of 144 simplex families consisting of parent and affected child, as well as 88 healthy, unrelated control subjects were available for study. In these individuals, 9 polymorphic positions of TNF were typed by a high-throughput genotyping method based on the SNaPshot assay. The chi-square and extended transmission disequilibrium tests were used to test for association and linkage, respectively. Odds ratios (ORs) with 95% confidence intervals (95% CIs) were also calculated. Haplotype-tagging SNPs (htSNPs) for the locus were identified by ordering the haplotypes according to their frequencies.

RESULTS

The study detected association of several TNF SNPs and established linkage of the locus to juvenile oligoarthritis. The most significant association observed was between the intronic +851 TNF SNP and the persistent oligoarthritis subgroup (OR 3.86, 95% CI 1.6-9.2). Haplotype data mining showed that only 4 of the 9 SNPs need to be typed in order to capture the most frequent TNF haplotypes.

CONCLUSION

The TNF locus is linked and associated with juvenile oligoarthritis. Information on the htSNPs can be useful in genetic studies of diseases in which TNF may be of relevance.

Elevated C-reactive protein and pro-inflammatory cytokines in Andean women with pre-eclampsia

OBJECTIVE

To investigate the concentration of markers of inflammation in non-pregnant women, women with normal pregnancy and women with pre-eclampsia.

METHODS

Pregnant women (n=26), women with pre-eclampsia (n=25) and non-pregnant normotensive women (n=21) were included in the study. C-reactive protein was measured by latex-enhanced immunoturbidimetric assay, serum tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) by high sensitivity ELISA. Kruskal-Wallis non-parametric analysis of variance followed by the Mann-Whitney U-test were used for statistical analyses.

RESULTS

Higher values (mean+/-S.E.M.) of C-reactive protein were found in pre-eclampsia (4.11+/-0.37 mg/dl) compared with normal pregnant women (2.49+/-0.26 mg/dl) and non-pregnant controls (1.33+/-0.15 mg/dl). TNF-alpha was significantly higher in women with pre-eclampsia (15.74+/-5.09 pg/ml), in relation to the control group (2.76+/-0.41 pg/ml) and women with normal pregnancy (8.31+/-1.55 pg/ml). IL-6 levels were significantly higher in pre-eclamptic women (12.91+/-1.29 pg/ml) compared with normal pregnant (5.07+/-0.423 pg/ml) and control women (1.25+/-0.13 pg/ml).

CONCLUSIONS

The results of this cross-sectional study in a high-risk Andean population show that both C-reactive protein and pro-inflammatory cytokines are present in higher concentrations in women with pre-eclampsia. The study was undertaken in women with established pre-eclampsia and it is not possible to determine whether the increased concentrations of C-reactive protein and pro-inflammatory cytokines were a cause or consequence of the disease.

Synovial fluid cytokines and eicosanoids as markers of joint disease in horses

OBJECTIVE

To evaluate the value of various synovial fluid cytokines and eicosanoids to diagnose joint disease or categories of joint disease.

STUDY DESIGN

Prospective acquisition of clinicopathologic data.

ANIMALS OR SAMPLE POPULATION

Client-owned or donated horses: 50 joints with no evidence of disease; 28 joints with acute disease; 32 joints with chronic disease; 9 joints with cartilage damage and no other signs of joint disease.

METHODS

Concentrations of tumor necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta), interleukin-6 (IL-6), prostaglandin E(2) (PGE(2)), thromboxane B(2) (TXB(2)), prostaglandin F1-alpha (PGF(1)-alpha), and leukotriene B(4) (LTB(4)), were measured in equine synovial fluid by immunoassay and categorized according to duration and degree of joint disease. Any test value for a given category that was different from normal was further analyzed for sensitivity (S), specificity (Sp), and operating point (most valid test cutoff value). Likelihood ratios and predictive values were calculated at the operating point. Mediator concentrations were correlated to synovial fluid white blood cell count. Tests were reported as poor, fair, good, or excellent based on predictive values of <.25,.25-.5,.5-.75, or >.75, respectively.

RESULTS

TNF synovial fluid concentration as a predictor of joint disease was good, and the value of TNF (maximum S and Sp) indicating joint disease was >36 pg/mL. IL-1beta as a predictor of joint disease was good, and the value of IL-1beta indicating joint disease was >4.5 pg/mL. IL-6 concentration was an excellent predictor of joint disease. Any IL-6 in synovial fluid indicated joint disease and correlated highly with synovial fluid white blood cell count (P <.0001). PGE(2) was a good-excellent predictor of disease (positive predictive value [PPV] = 0.75), and the concentration indicating joint disease was >22.5 pg/mL. The diagnostic PGF(1)-alpha concentration indicating severe chronic joint disease was identified to be >16.5 pg/mL with very high sensitivity (S = 1) and specificity (Sp =.89). PGF(1)-alpha concentrations > 9.5 pg/mL had a good PPV (.69) and NPV (.6) for any joint disease. TBX(2) concentrations below 31.5 pg/mL (S =.57; Sp =.61) were a very good predictor of joint disease (PPV =.72). LTB(4) concentration appeared to be greater in severe acute joint disease than normal joints; this was not significant (P =.15) and correlated highly with synovial fluid white blood cell count (P =.0001).

CONCLUSIONS

The ability of a single value from a joint in an adult horse predicting the presence of joint disease was often good (.5-.75), and was excellent (> or =.75) for IL-6 and PGE(2). TNF-alpha and IL-1beta were no more effective than white blood cell count in screening for joint disease. IL-6 was the most sensitive and specific for joint disease and could be an excellent screening test for the presence of joint disease when lameness is difficult to identify or is intermittent. PGE(2) would be a functional screening test for the presence of any joint disease and offers a differentiating feature because values were not influenced by white blood cell count. PGF(1)-alpha values > 16.5 pg/mL identified chronic severe joint disease and may be clinically useful when there are minimal radiographic changes but substantial articular cartilage degradation.

Interleukin 6 and C-reactive protein levels in patients with acute allergic reactions: an emergency department-based study

BACKGROUND

Elevations of interleukin 6 (IL-6) have been described in drug-induced anaphylaxis. Although IL-6 is well known to stimulate an acute phase response, profiling acute phase protein levels, such as C-reactive protein (CRP), has, to our knowledge, never been performed in patients with acute allergic reactions.

OBJECTIVE

To examine the pattern of IL-6 and CRP levels in patients with acute allergic reactions and to relate these to relevant clinical and laboratory parameters.

METHODS

Plasma CRP and serum IL-6 levels were determined in 85 adult emergency department patients. These patients had been previously studied with questionnaires, physical examinations, and histamine/tryptase levels. Clinical and historical features were related to CRP and IL-6 levels. CRP and IL-6 levels were also examined for relationships with histamine and tryptase levels.

RESULTS

CRP and IL-6 levels were significantly correlated with one another in the study patients (Spearman p = 0.36, P = 0.0008). Similar to histamine levels, IL-6 levels were significantly correlated with the extent of erythema manifested by the study patients. The extent of erythema was independently predicted by both IL-6 and histamine levels. Histamine levels were negatively correlated with CRP levels (Spearman p = -0.32, P = 0.003). Unlike histamine levels, IL-6 and CRP did not show significant relationships with the extent or presence of urticaria/angioedema or the presence of wheezing. IL-6 levels were correlated with the duration of symptoms before serologic sampling. An inverse correlation was observed between IL-6 levels and mean arterial blood pressure. Multivariate modeling showed significant independent effects from mean arterial pressure, duration of symptoms, erythema extent, and age in predicting IL-6 levels. Tryptase levels were higher in patients whose IL-6 levels were >20 pg/mL.

CONCLUSIONS

CRP and IL-6 levels are not simple surrogate markers for histamine or tryptase release by mast cells or basophils in acute allergic reactions. Increasing IL-6 levels relate to greater erythema extent, lower mean arterial blood pressure, and a longer duration of symptoms. It would be interesting to speculate that CRP and IL-6 increases characterize a late-phase response in immediate hypersensitivity reactions. In this perspective, the inverse relationship between CRP and histamine levels could be explained. As histamine levels are waning, CRP levels are increasing. Timed studies for histamine and CRP/IL-6 levels in allergic reactions are necessary to confirm this hypothesis.

Association of cytokine polymorphic inheritance and in vitro cytokine production in anti-CD3/CD28-stimulated peripheral blood lymphocytes

BACKGROUND

Genetic variations in cytokine genes are thought to regulate cytokine protein production. However, studies using T cell mitogens have not always demonstrated a significant relationship between cytokine polymorphisms and in vitro protein production. Furthermore, the functional consequence of a polymorphism at position -330 in the IL-2 gene has not been described. We associated in vitro protein production with cytokine gene polymorphic genotypes after costimulation of cultured peripheral blood lymphocytes.

METHODS

PBL were isolated from forty healthy volunteers. Cytokine protein production was assessed by enzyme-linked immunosorbent assay. Polymorphisms in interleukin- (IL) 2, IL-6, IL-10, tumor necrosis factor (TNF-alpha), tumor growth factor (TGF-beta), and interferon (IFN-gamma) were determined by polymerase chain reaction (PCR).

RESULTS

Statistical difference between protein production and cytokine polymorphic variants in the IL-10, IFN-gamma, and TNF-alpha genes was not evident after 48-hour stimulation with concanavalin-A. In contrast, after anti-CD3/CD28 stimulation significant differences (P<0.05) were found among high and low producers for IL-2, IL-6, and among high, intermediate, and low producers for IFN-gamma, and IL-10. Augmented levels of IL-2 in individuals that were homozygous for the polymorphic IL-2 allele were due to an early and sustained enhancement of IL-2 production. No association was found among TNF-alpha and TGF-beta genotypes and protein production.

CONCLUSION

Polymorphisms in IL-2, IL-6, IL-10, and IFN-gamma genes are associated with their protein production after anti-CD3/CD28 stimulation. The profound effect of the IL-2 gene polymorphism in homozygous individuals may serve as a marker for those that could mount the most vigorous allo- or autoimmune responses, or perhaps become tolerant more easily.

Cytokine gene polymorphisms and susceptibility to juvenile idiopathic arthritis. British Paediatric Rheumatology Study Group

OBJECTIVE

To investigate the involvement of candidate cytokine genes in the pathogenesis of juvenile idiopathic arthritis (JIA).

METHODS

Single nucleotide polymorphisms and intragenic microsatellite markers within 8 candidate cytokine genes (interleukin-1alpha [IL-1alpha], IL-2, IL-4, IL-6, IL-10, interferon-alpha1 [IFNA1], interferon-gamma [IFNG], and interferon regulatory factor 1 [IRF-1]) were investigated in 417 Caucasian patients with clinically characterized JIA and a panel of 276 unrelated, healthy Caucasian controls, all from the United Kingdom.

RESULTS

A novel 3'-untranslated region (3'UTR) polymorphism in IRF-1 was found to be associated with susceptibility to JIA (corrected P = 0.002). No significant association with IL-1alpha, IL-2, IL-4, IL-6, IL-10, IFNA1, or IFNG was observed.

CONCLUSION

An association between JIA and a previously unreported 3'UTR polymorphism of IRF-1 was observed. This association was not found to be specific to any particular JIA subgroup. This suggests that IRF-1 may contribute to a common pathogenesis shared by all JIA patients, regardless of clinical phenotype. This is most likely to be a genetic contribution to the chronic inflammatory process that underlies JIA pathology.

Use of biologics in the treatment of childhood rheumatic diseases

Over the last two decades, progression in the knowledge of molecular biologic techniques has led to a better understanding of immunopathogenesis and identification of several cytokines, which propagate chronic arthritis in both adult and pediatric patients. A number of biologic agents have been developed in targeting different immune markers or mediators with the hope that they may help in controlling the inflammation in the group of patients who are resistant to disease-modifying antirheumatic drugs (DMARDs) and may alter the natural history of the diseases. Tumor necrosis factor (TNF)-alpha is the first to be targeted and its antagonists have been approved. Other biologic agents targeting different markers/mediators have followed and have been tested in clinical trials especially in adult rheumatoid arthritis (RA). Experiences in pediatric use are limited and agents proved to be effective in adult RA are not always transferred the same efficacy in different subtypes of juvenile idiopathic arthritis (JIA). It is reasonable to see the efficacy, and more importantly the safety profiles of each agent before the decision is made to use them in children. This article reviews the published and anecdotal reports of biologic agents that have been used in children with JIA and also focuses on the potential use of other biologic agents in JIA that have been used in trials to combat adult RA.

Cytokines in Mycoplasma hyorhinis-induced arthritis in pigs bred selectively for high and low immune responses

Yorkshire pigs were bred selectively for high and low immune responses (H and L pigs, respectively) based on multiple antibody (Ab) and cell-mediated immune response traits. In a previous experiment, generation 4 (G4) pigs of each line were infected with Mycoplasma hyorhinis. High responders had a more rapid and higher Ab response and less polyserositis, but arthritis was more severe in H pigs than in L pigs. To test the hypothesis that line differences were attributable to differential expression of cytokines, M. hyorhinis infection was induced in pigs of G8. Arthritis was more severe clinically (P, </=0.05) and postmortem (P, </=0.001) when M. hyorhinis CFU were more numerous in synovial fluid (SF) of H pigs than of L pigs (P, </=0.03). In H pigs but not L pigs, CFU and lesion scores were correlated positively. In H pigs, infection increased the frequency of expression of mRNAs for interleukin-8 (IL-8), IL-10, and tumor necrosis factor alpha (TNF-alpha) in mononuclear cells from synovial membranes (SM). In L pigs, IL-1alpha, IL-6, IL-10, and TNF-alpha mRNAs were increased in frequency of expression. The quantity of the cytokine message for IL-6 was increased in infected H pigs. For L pigs, infection increased the cytokine message for IL-1alpha, IL-6, IL-10, and TNF-alpha. IL-6 in SM and gamma interferon (IFN-gamma) in SF were produced at a higher copy number in H pigs than in L pigs after infection. For H pigs, there were no positive rank correlations between lesion or CFU scores and cytokines. For L pigs, IL-1alpha, IL-8, IL-10, and TNF-alpha in SM correlated with CFU, while IL-6, TNF-beta, and IFN-gamma in SF correlated with CFU. Lesion score in L pigs correlated with IL-1alpha in SF. While these results indicate that H and L pigs differ in the cytokine response to M. hyorhinis infection, they do not confirm a characteristic cytokine response in association with the relative susceptibility to infection and arthritis observed in H pigs.

Immunopathogenesis of juvenile rheumatoid arthritis

The immunopathogenic mechanisms of juvenile rheumatoid arthritis (JRA) have been debated. A possible cellular-mediated hypothesis versus a possible B cell hyperreactivity have been entertained. This review will focus on some recent cellular work in JRA and also further evaluation of cytokine levels and their role in inflammation in JRA. Recent studies have evaluated the interrelationship of Th1/Th2 immune responses in the immunopathogenesis of JRA, and their effect on cytokine release. Studies have indicated a pro-inflammatory response in systemic-onset JRA manifested by increased secretion of interleukin-6, whereas an anti-inflammatory response has been noted by increases of IL-4 mRNA and IL-10 mRNA in pauciarticular-onset JRA. The continued finding of elevated levels of tumor necrosis factor-alpha (TNF-alpha) and its receptors in association with inflammatory activity has been seen. The recent use of a TNF fusion protein to block TNF-alpha activity in JRA has further contributed to this finding. Further studies on specific cytokines will be helpful in the future in trying to determine the different roles cytokines play in JRA subtypes and would contribute to the development of better therapeutic regimens.