Macrophage activation syndrome as part of systemic juvenile idiopathic arthritis: diagnosis, genetics, pathophysiology and treatment.

Macrophage activation syndrome (MAS) is a severe, frequently fatal complication of systemic juvenile idiopathic arthritis (sJIA) with features of hemophagocytosis leading to coagulopathy, pancytopenia, and liver and central nervous system dysfunction. MAS is overt in 10% of children with sJIA but occurs subclinically in another 30-40%. It is difficult to distinguish sJIA disease flare from MAS. Development of criteria for establishing MAS as part of sJIA are under way and will hopefully prove sensitive and specific. Mutations in cytolytic pathway genes are increasingly being recognized in children who develop MAS as part of sJIA. Identification of these mutations may someday assist in MAS diagnosis. Defects in cytolytic genes have provided murine models of MAS to study pathophysiology and treatment. Recently, the first mouse model of MAS not requiring infection but rather dependent on repeated stimulation through Toll-like receptors was reported. This provides a model of MAS that may more accurately reflect MAS pathology in the setting of autoinflammation or autoimmunity. This model confirms the importance of a balance between pro- and anti-inflammatory cytokines. There has been remarkable progress in the use of anti-pro-inflammatory cytokine therapy, particularly against interleukin-1, in the treatment of secondary forms of MAS, such as in sJIA.

Analysis of integrated virological and epidemiological reports of norovirus outbreaks collected within the Foodborne Viruses in Europe network from 1 July 2001 to 30 June 2006.

The Foodborne Viruses in Europe network has developed integrated epidemiological and virological outbreak reporting with aggregation and sharing of data through a joint database. We analyzed data from reported outbreaks of norovirus (NoV)-caused gastroenteritis from 13 European countries (July 2001 to July 2006) for trends in time and indications of different epidemiology of genotypes and variants. Of the 13 countries participating in this surveillance network, 11 were capable of collecting integrated epidemiological and virological surveillance data and 10 countries reported outbreaks throughout the entire period. Large differences in the numbers and rates of reported outbreaks per country were observed, reflecting the differences in the focus and coverage of national surveillance systems. GII.4 strains predominated throughout the 5-year surveillance period, but the proportion of outbreaks associated with GII.4 rose remarkably during years in which NoV activity was particularly high. Spring and summer peaks indicated the emergence of genetically distinct variants within GII.4 across Europe and were followed by increased NoV activity during the 2002-2003 and 2004-2005 winter seasons. GII.4 viruses predominated in health care settings and in person-to-person transmission. The consecutive emergence of new GII.4 variants is highly indicative of immune-driven selection. Their predominance in health care settings suggests properties that facilitate transmission in settings with a high concentration of people such as higher virus loads in excreta or a higher incidence of vomiting. Understanding the mechanisms driving the changes in epidemiology and clinical impact of these rapidly evolving RNA viruses is essential to design effective intervention and prevention measures.

Data quality of 5 years of central norovirus outbreak reporting in the European Network for food-borne viruses.

BACKGROUND: The food-borne viruses in Europe (FBVE) network database was established in 1999 to monitor trends in outbreaks of gastroenteritis due to noroviruses (NoVs), to identify major transmission routes of NoV infections within and between participating countries and to detect diffuse international food-borne outbreaks. METHODS: We reviewed the total of 9430 NoV outbreak reports from 13 countries with date of onset between 1 January 2002 and 1 January 2007 for representativeness, completeness and timeliness against these objectives. RESULTS: Rates of reporting ranged from a yearly average of 1.8 in 2003 to 11.6 in 2006. Completeness of reporting of an agreed minimum dataset improved over the years, both for epidemiological and virological data. For the 10 countries that provided integrated (epidemiological AND virological) reporting over the 5-year period, the completeness of the minimum dataset rose from 15% in 2003 to 48% in 2006. Two countries have not been able to combine both data types due to the structure of the national surveillance system (England and Wales and Germany). Timeliness of reporting (median days between the onset of an outbreak and the date of reporting to the FBVE database) differed greatly between countries, but gradually improved to 47 days in 2006. CONCLUSION: The outbreaks reported to the FBVE reflect the lack of standardization of surveillance systems across Europe, making direct comparison of data between countries difficult. However, trends in reported outbreaks per country, distribution of NoV genotypes, and detection of diffuse international outbreaks were used as background data in acute questions about NoV illness and the changing genotype distribution during the 5-year period, shown to be of added value. Integrated reporting is essential for these objectives, but could be limited to sentinel countries with surveillance systems that allow this integration. For successful intervention in case of diffuse international outbreaks, completeness and timeliness of reporting would need to be improved and expanded to countries that presently do not participate.

Systemic features and early prognostic factors in Hispanic and non-Hispanic children from the United States of America and Mexico with systemic juvenile idiopathic arthritis.

OBJECTIVE: To investigate if the persistence of systemic features is longer in Hispanic children with systemic juvenile idiopathic arthritis (S-JIA) than in non-Hispanic children with S-JIA and to determine early predictors of systemic and articular disease. METHODS: We performed a multi-center retrospective chart review of patients followed in six pediatric rheumatology centers with onset of S-JIA from 1974 to 2004. Patients were included in the study if they had been followed for > or = 1 year after disease onset. Information collected included demographic, clinical, laboratory and treatment data. Systemic features included fever, rash, lymphadenopathy, hepatosplenomegaly, pericarditis, and pleuritis. RESULTS: Of the 159 S-JIA patients screened, 120 (75%) met our inclusion criteria. There were 65 boys and 55 girls. The mean follow-up period for Hispanic patients was 5.7 years (SD 4.0) and for non-Hispanic patients was 8.6 years (SD 7.2). There was no significant difference in the presence of systemic features between Hispanic and non-Hispanic patients at 0.5, 1, 2, 4, 6, 8, and 10 years of follow-up. Polyarthritis at the 6-month visit was predictive of systemic features (OR 9.7, 95% CI 1.16-81.35, p = 0.036) and polyarthritis (OR 5.6, 95% CI 1.42-21.8, p = 0.014) at last follow-up. CONCLUSION: In children with S-JIA, Hispanics did not demonstrate longer persistence of systemic features than non-Hispanics. Polyarthritis at 6 months strongly predicted the development of persistent systemic features and chronic polyarticular disease.

Does systemic-onset juvenile idiopathic arthritis belong under juvenile idiopathic arthritis?

'Science is the systematic classification of experience' George Henry Lewes (1817-78), English philosopher, critic, dramatist, scientist. Juvenile idiopathic arthritis (JIA) is prevalent in about 1 in 1000 children. The earliest formal description of this disease was by Sir George Frederick Still in 1897. This work was done when he was a registrar at the Hospital for Sick Children, Great Ormond Street, London. In this initial description of 19 patients he identified three patterns of arthritis, one of which came to be known later as Still's disease [now known as systemic-onset juvenile idiopathic arthritis (SoJIA)]. Over the next few decades it came to be appreciated that one form of arthritis in children is very different and dominated by the presence of systemic manifestations. Over the last two decades several paediatric rheumatologists have come together to classify juvenile arthritis for purposes of better disease identification and research. All along, the systemic form of juvenile arthritis was always recognized as belonging to a distinct group; in fact for several decades (and even now in some countries) the systemic form of juvenile arthritis was referred to as Still's disease. In this article we will attempt to highlight the reasons why we feel that SoJIA is perhaps not best retained in the company of JIA.

Angiopoietin-like-4 is a potential angiogenic mediator in arthritis.

Our previous studies of gene expression profiling during collagen-induced arthritis (CIA) indicated that the putative angiogenic factor Angptl4 was one of the most highly expressed mRNAs early in disease. To investigate the potential involvement of Angptl4 in CIA pathogenesis, Angptl4 protein levels were assessed at early stages of disease and its cellular sources were determined. In addition, the functional effects of mouse Angptl4 on endothelial cells were assessed. Angptl4 protein levels were higher in arthritic joints as compared to normal joints. In situ hybridization localized Angptl4 mRNA to stromal fibroblast-like cells within the inflamed synovium. Temporal expression of Angptl4 mRNA during CIA was similar to that of key angiogenic factors, including structurally related angiopoietin 1. Recombinant mouse Angptl4 promoted endothelial cell survival and formation of tubule-like structures. These functional effects of Angptl4, combined with very high expression at early stages of CIA, suggest a role for Angptl4 in angiogenesis in arthritis.

Gene expression in juvenile arthritis and spondyloarthropathy: pro-angiogenic ELR+ chemokine genes relate to course of arthritis.

OBJECTIVE: To evaluate the ability of microarray-based methods to identify genes with disease-specific expression patterns in peripheral blood mononuclear cells (PBMC) and synovial fluid mononuclear cells (SFMC) of juvenile arthritis patients and healthy controls. METHODS: Microarray data (Affymetrix U95Av2) from 26 PBMC and 20 SFMC samples collected from patients with active disease (classified by course according to ACR criteria) were analysed for expression patterns that correlated with disease characteristics. For comparison, PBMC gene expression profiles were obtained from 15 healthy controls. Real-time PCR was used for confirmation of gene expression differences. RESULTS: Statistical analysis of gene expression patterns in PBMC identified 378 probe sets corresponding to 342 unique genes with differing expression levels between polyarticular course patients and controls (t test, P<0.0001). The genes represented by these probe sets were enriched for functions related to regulation of immune cell functions, receptor signalling as well as protein metabolism and degradation. Included in these probe sets were a group of CXCL chemokines with functions related to angiogenesis. Further analysis showed that, whereas angiogenic CXCL (ELR+) gene expression was elevated in polyarticular PBMC, expression of angiostatic CXCL (ELR-) chemokines was lower in polyarticular SFMC compared with corresponding pauciarticular samples (t test, P<0.05). CONCLUSIONS: This pilot study demonstrates that juvenile arthritis patients exhibit complex patterns of gene expression in PBMC and SFMC. The presence of disease-correlated biologically relevant gene expression patterns suggests that the power of this approach will allow better understanding of disease mechanisms, identify distinct clinical phenotypes in disease subtypes, and suggest new therapeutic approaches.

[New aspects of ICD therapy: from rhythm therapy to complex cardiac monitoring. Development of an implantable, ICD-assisted, intrathoracic 6-channel ECG for continuous monitoring of high infarct risk patients]. / Neue Aspekte der ICD-Therapie: Von der Rhythmustherapie zur komplexen kardialen Uberwachung. Entwicklung eines implantierbaren, ICD-gestützten, intrathorakalen 6-Kanal-EKG zur kontinuierlichen Uberwachung von infarktgefährdeten Risikopatienten.

Implantable defibrillator systems (ICD) are therapy of choice for the treatment of life-threatening ventricular arrhythmias and in prevention of sudden cardiac death. In more than 80% of patients who receive an ICD, the underlying cardiac disease is a coronary heart disease. Since arrhythmogenic sudden cardiac death can be reliably prevented in these patients by the use of ICD technology, the cardiac prognosis for these patients is determined by the occurrence of myocardial ischemia and myocardial infarction, as well as from the heart failure which develops in consequence. An intrathoracic 6-channel ECG comparable to the standard surface ECG can be reconstructed by further technical development of the electrode configurations currently present in ICD systems. The importance of this development in early diagnosis of myocardial ischemias and myocardial infarction can hardly be adequately estimated at the moment. The chronic consequences of myocardial infarction can be completely prevented or at least greatly reduced by means of such diagnostics and inclusion of immediate initiation of effective, appropriate early therapeutic measures before more serious symptoms even occur. In the development and pilot studies thus far, it has been found that the intrathoracic 6-channel ECG which can be generated in the ICD is capable of reliably recognizing acute myocardial ischemia, irrespective of localization or extent earlier and better than the standard surface ECG. Continuous preventive ischemia monitoring using the implanted ICD thus appears possible in patients at risk of infarction.

Etanercept in the treatment of macrophage activation syndrome.

Macrophage activation syndrome (MAS), a recognized complication of systemic juvenile rheumatoid arthritis (sJRA), has been associated with significant morbidity and mortality. Dysregulation of macrophage-lymphocyte interactions leading to uncontrolled proliferation of highly activated macrophages and massive release of proinflammatory cytokines including tumor necrosis factor-alpha (TNF-alpha) appears to be central to the pathogenesis of this syndrome. Until now the mainstay of therapy has been corticosteroids and cyclosporin A. We describe a patient with MAS and sJRA successfully treated with the anti-TNF agent etanercept. The outcome in this patient suggests etanercept might be an effective therapeutic agent in MAS.

Expression of angiogenic factors in juvenile rheumatoid arthritis: correlation with revascularization of human synovium engrafted into SCID mice.

OBJECTIVE: Although increased vascularity was noted in early histopathologic studies of juvenile rheumatoid arthritis (JRA) synovium, the available data on angiogenesis in JRA are very limited. The main purposes of this study were to assess expression of the key angiogenic factors in JRA synovium, and to evaluate a SCID mouse model of JRA as an approach to study in vivo regulation of the expression of these factors in JRA. METHODS: RNase protection assay was used to assess the expression of the key angiogenic factors in fresh JRA synovium and in JRA synovial tissue fragments that had been minced and then implanted into SCID mice. Vascularity of the samples was assessed by immunohistochemical staining for von Willebrand factor. Synovial specimens obtained from patients with osteoarthritis (OA) or other noninflammatory arthropathies were used as controls. RESULTS: Detectable levels of messenger RNA for vascular endothelial growth factor and angiopoietin 1 and their respective receptors, as well as endoglin and thrombin receptors, were present in all JRA tissue specimens studied. The levels of expression of these factors in JRA tissues were significantly higher than those in tissues obtained from patients with OA or other noninflammatory arthropathies. Furthermore, increased expression of the key angiogenic factors in the fresh JRA tissues correlated with the exuberant revascularization of JRA minced tissue fragments implanted into SCID mice. This was in sharp contrast to the poor revascularization of implanted OA tissues. CONCLUSION: JRA synovium is characterized by high angiogenic activity. SCID mouse-human JRA synovium chimeras may provide a good approach to study the in vivo regulation of angiogenesis in JRA.

Clusters of life-threatening ventricular arrhythmias in patients with implanted cardioverter-defibrillators: prevalence, characteristics, and risk stratification.

BACKGROUND: Series of discharges from an implanted defibrillator (ICD) to terminate life-threatening ventricular tachyarrhythmias are one particular aspect of energy use and success of ICD therapy. Little is known about prevalence. characteristics, and risk stratification of so-called "cluster arrhythmias." HYPOTHESIS: The objective of this study was to examine the frequency of cluster arrhythmias, to characterize the temporal relationship precisely, and to assess the accompanying circumstances of their occurrence, whereby risk stratification was to be made if appropriate. METHODS: In all, 63 consecutive patients were followed prospectively over 727 +/- 684 days to determine the presence and characteristics of cluster arrhythmias (45,801 patient days). In 30 patients, 374 ICD episodes of ventricular tachyarrhythmias were analyzed for their temporal relationship. After a first successfully terminated ventricular tachyarrhythmia, further ICD discharges within 3 h were observed during 145 of 374 (39%) episodes; mean time interval between these arrhythmias was 25 +/- 32 min. RESULTS: Arrhythmia clusters occurred in 19 of 30 (63%) patients. In multivariate analysis, only underlying heart disease was predictive for accumulation of ventricular tachyarrhythmias. Cluster arrhythmias were more frequent among patients with ischemic heart disease than among those with nonischemic heart disease (40.0 vs. 29.2%, p < 0.05). Ejection fraction, age, gender, and other parameters were not predictive for occurrence of arrhythmia clusters. In 4 of 19 patients, accumulation of ICD discharges was predictive for new onset of myocardial ischemia elicited by exercise test. CONCLUSIONS: Cluster arrhythmias are most common in patients with ICDs with coronary heart disease and may indicate disease progression and increasing instability, for example, due to new onset of myocardial ischemia.

T-cell and T-cell receptor abnormalities in the immunopathogenesis of juvenile rheumatoid arthritis.

Several lines of indirect evidence suggest that the pathologic autoimmune responses in juvenile rheumatoid arthritis may be antigen-driven and T cell-mediated. These include (1) activation markers expressed on synovial T cells suggestive of previous activation in vivo; (2) persistent oligoclonally expanded T-cell populations accumulating preferentially in the synovial compartment; (3) some T-cell receptor complementarity-determining region 3 sequence similarities between different clones in an individual patient; and (4) T-cell derived cytokines of predominantly Th1 type. Whether T-cell contribution is limited to only early stages of the disease (as appears to be the case in collagen-induced arthritis) or T cells are required for the perpetuation of the inflammation at later stages as well, still remains to be determined.

[Acute myocardial ischemia and ventricular arrhythmias in the pathogenesis of sudden cardiac death in coronary disease]. / Akute Myokardischämie und ventrikuläre Arrhythmien in der Pathogenese des plötzlichen Herztodes bei koronarer Herzkrankheit.

There is increasing evidence for a fatal interaction of myocardial ischemia, ventricular arrhythmias and sudden cardiac death in some patients with coronary artery disease. Evidence comes from autopsy studies, from the evaluation of patients who survived an episode of sudden cardiac death, from follow-up data of these patients either treated or not by revascularization therapy and/or an implantable cardioverter-defibrillator and indicate that reducing the individual ischemic burden will be beneficial to reduce the incidence of sudden cardiac death. Studies in patients with stable and especially with unstable angina using Holter monitoring could demonstrate that there is a close and causal relationship between myocardial ischemia inducing or aggravating life-threatening ventricular arrhythmias and sudden cardiac death particularly in patients with unstable and postinfarction status. This review summarizes some of our clinical knowledge on this topic and indicates that preventive strategies for myocardial ischemia are the antiarrhythmic treatment of choice in patients with severe coronary artery disease and patients with evidence or at risk for ischemic proarrhythmia.

On the mechanism of protection of distal joints after local gene transfer in collagen-induced arthritis.

Considerable interest has been generated by the observation that adenovirus-mediated gene delivery to a single arthritic joint results in suppression of arthritis in distal joints associated with the presence of small numbers of transduced cells in distal joints. It has been proposed that this is mediated by trafficking of transduced cells from the injected to distal joints. There are, however, alternative explanations that have not been explored, including the possibility that transgene protein or infectious virions circulate to distal sites. To investigate these possibilities, a replication-incompetent adenovirus encoding viral IL-10 (vIL-10) was administered to naive mice and to mice with collagen-induced arthritis by intraarticular, periarticular, or intravenous injection. In all cases, the ability to protect distal joints correlated with serum levels of vIL-10 protein. After intraarticular or intravenous injection, vIL-10 cDNA could be detected not only in distal joints, but also in the liver, which is the major target of circulating adenovirus, demonstrating that adenovirus circulating through the bloodstream is taken up by the joint tissue. Periarticular administration of adenovirus, which resulted in lower serum levels of vIL-10, protected only the injected paws and failed to induce trafficking immunoregulatory cells capable of suppressing distal disease. These observations suggest that circulating vIL-10 protein is the major mediator of distal protection. The presence of small numbers of transduced cells at distal sites can be accounted for by transduction of distal synovium after entry of adenovirus virions into the circulation.

Contrasting cytokine profiles in the synovium of different forms of juvenile rheumatoid arthritis and juvenile spondyloarthropathy: prominence of interleukin 4 in restricted disease.

OBJECTIVE: To determine the pattern of expression of Type 1 and Type 2 cytokines in synovial tissues and fluids (SF) of patients with different forms of juvenile rheumatoid arthritis (JRA) and juvenile spondyloarthropathy (JSpA), and to contrast these with findings in adult patients with RA. METHODS: Sixty-three SF mononuclear cell preparations and synovial tissue samples from 50 patients with JRA or JSpA and 7 synovial tissues from patients with adult onset RA were analyzed by reverse transcription polymerase chain reaction for the presence or absence of interleukin 2 (IL-2), tumor necrosis factor-beta (TNF-beta), interferon-gamma (IFN-gamma), and IL-10 and IL-4 mRNA. RESULTS: IL-4 mRNA was identified significantly more often in the synovial compartment of patients with pauciarticular onset disease (JRA or JSpA) compared with polyarticular onset JRA (58 vs 14%; p < 0.01) or RA (29%). Similarly, IL-4 mRNA was detected more often in those with a persistently pauciarticular disease course compared to those with a polyarticular course (68 vs 30%; p < 0.01). Furthermore, the combination of IL-4 and IL-10 mRNA was found more frequently in nonerosive compared with erosive disease (38 vs 15%; p < 0.05). IL-2 and TNF-beta mRNA were found in all groups. IFN-gamma mRNA was detected in 33% of those with systemic onset JRA compared with 85% of other types of JRA (p < 0.01). CONCLUSION: This study provides further evidence of immunopathological differences between chronic forms of arthritis with childhood onset, and highlights similarities with and differences from adult RA. Our findings suggest that IL-4, possibly in combination with IL-10, has an antiinflammatory or disease restricting role.

Comparative sequence analysis of the human T cell receptor beta chain in juvenile rheumatoid arthritis and juvenile spondylarthropathies: evidence for antigenic selection of T cells in the synovium.

OBJECTIVE: To identify features of the T cell receptors (TCRs) present on clonally expanded T cells in the joints of patients with similar types of childhood rheumatic disease. Vbeta8 and Vbeta20 TCRs were selected as prototypic for polyarticular juvenile rheumatoid arthritis (JRA) and pauciarticular/juvenile spondylarthropathy (SpA), respectively. METHODS: The portion of the TCR beta chain involved in antigen recognition in the synovial tissue, synovial fluid, and peripheral blood from patients with JRA and juvenile SpA was cloned and sequenced. The frequency of expanded clonotypes, size of expansions, the Jbeta region, and sequence motifs were determined for >2,000 sequences. RESULTS: The majority of Vbeta20 and Vbeta8 clonal expansions were found in the joint rather than the peripheral blood. While instances of both Vbeta8 and Vbeta20 clonal expansion were detected in all disease types, the features of these expanded clonotypes were specific for disease type and Vbeta family. For example, Vbeta20 clonal expansion was characterized by many small expanded clonotypes in samples from patients with pauciarticular JRA and juvenile SpA while single large Vbeta8-specific expansions were found only in patients with polyarticular disease. Motifs specific to individual patients were identified, and for Vbeta20 clonotypes, a motif was found in synovial tissue samples. CONCLUSION: Identification of common TCR features in oligoclonal expansions within individual patients and between patients with the same type of JRA suggests the recognition of a common or limited group of antigens in these diseases.

Antibodies to the 45 kDa DEK nuclear antigen in pauciarticular onset juvenile rheumatoid arthritis and iridocyclitis: selective association with MHC gene.

OBJECTIVE: To study the frequency of autoantibodies to the 45 kDa DEK nuclear antigen, a putative oncoprotein, in a sample of patients with juvenile rheumatoid arthritis (JRA), and to make correlations with disease subtype and complications such as iridocyclitis. Class I and Class II HLA associations with reactivity to the antigen were also sought. METHODS: Sera from 146 HLA typed patients with JRA representing all subtypes were analyzed for reactivity with the 45 kDa DEK protein by immunoblotting. The antigen was purified to near homogeneity from nuclei of HeLa cells. RESULTS: Antibodies to DEK were found in 57% of all patients with JRA compared to 3% of controls (p < 0.0001). Antibodies were detected more frequently in pauciarticular onset (78%) than in polyarticular onset patients (29%; p < 0.01) and controls (3%; p < 0.0001). 97% of patients with JRA (regardless of onset subtype) and iridocyclitis had anti-DEK antibodies compared to 47% of patients without eye disease (p < 0.0001). Anti-DEK antibodies were found more frequently in females compared to males in the pauciarticular onset disease group (84 vs 42%; p < 0.01). The occurrence of anti-DEK antibodies was closely associated with positive antinuclear antibody serology, and a strong association with the Class I gene HLA-A2 was also observed. CONCLUSION: Antibodies to the 45 kDa DEK protein are characteristic of the pauciarticular onset subtype of JRA, particularly in patients with a history of iridocyclitis. The occurrence of anti-DEK antibodies is significantly but paradoxically associated with the presence of the HLA-A2 allele in such patients.

Immunohistological characteristics of T cell infiltrates in different forms of childhood onset chronic arthritis.

OBJECTIVE: To characterize synovial T cell infiltrate, in terms of CD4/CD8 ratio and level of activation of T cells, in juvenile rheumatoid arthritis (JRA) and juvenile spondyloarthropathy(JSpA), to correlate these findings with clinical outcomes of the different forms of disease, and to compare them with findings in adult RA synovium. METHODS: We studied synovial tissue specimens from 22 individuals with childhood onset of chronic arthritis (12 polyarticular JRA, 5 pauciarticular JRA, 5 JSpA) and 4 with adult RA. Specimens were selected from an initial bank from 40 patients on the basis of significant inflammation on hematoxylin and eosin and CD3 and CD68 monoclonal antibody staining (T cells and macrophages, respectively). Indirect immunohistochemistry was used with monoclonal antibodies to CD3, CD4, CD8, and interleukin 2 receptor alpha to determine CD4/CD8 ratios and the levels of activation within the T cell subsets. The distribution of gamma delta T cells was also studied. RESULTS: Two patterns of T cell infiltration were seen. The majority of patients had lymphocytic aggregates associated with diffuse infiltrates; a few tissue specimens had diffuse infiltrates without aggregates. The CD4/CD8 ratio was significantly lower in pauciarticular course JRA than polyarticular JRA (p < 0.01) and RA (p < 0.05). Similarly patients with JSpA had a significantly lower CD4/CD8 ratio than patients with polyarticular JRA (P < 0.05). The level of T cell activation (CD3+IL-2R+) was significantly higher in pauciarticular compared with both polyarticular JRA (P < 0.01) and RA (p < 0.05). In general, higher levels of activation of CD8 cells than CD4 cells were seen, particularly in the pauciarticular JRA and JSpA groups. gamma delta T cells were prominent in 2 patients. CONCLUSION: Demonstrated differences in T cell subset distribution between types of childhood chronic arthritis at a histopathological level may reflect different pathogenic mechanisms.

Patterns of expression of tumor necrosis factor alpha, tumor necrosis factor beta, and their receptors in synovia of patients with juvenile rheumatoid arthritis and juvenile spondylarthropathy.

OBJECTIVE: To assess the expression of tumor necrosis factor alpha (TNF alpha), TNF beta, and their receptors in synovia of patients with juvenile rheumatoid arthritis (JRA) and juvenile spondylarthropathy (JSpA), and to determine similarities with and differences from adult RA. METHODS: Twenty-eight synovial tissue samples from patients with JRA, 6 from patients with JSpA, and 6 from patients with RA, selected for the presence of inflammatory infiltrates, were analyzed for the expression of TNF alpha, TNF beta, and their receptors (p55 and p75 TNFR), utilizing the dual approach of reverse transcriptase-polymerase chain reaction and immunohistochemistry analysis. RESULTS: The presence of both TNF alpha and TNF beta expression was demonstrated in most JRA and JSpA tissues, although samples from patients with pauciarticular JRA had somewhat lesser amounts of these cytokines. TNF beta expression correlated significantly with the occurrence of lymphocytic aggregates in tissues. Staining with monoclonal antibodies specific for the p55 and p75 receptors revealed that a diverse range of cell types expressed the receptors, with the most intense p55 staining on vascular endothelial cells. In the vast majority of synovial tissues, far greater numbers of cells expressed the p55 form of the receptor than the p75 form. CONCLUSION: JRA and JSpA synovia are characterized by the presence of TNF alpha, TNF beta, and cells expressing TNFR. These findings provide further evidence that TNF, through autocrine/paracrine mechanisms, may amplify local inflammation, leading to joint destruction. The prominence of TNF beta in the synovium in particular subgroups of JRA patients and in JSpA patients may be a distinguishing feature of these diseases.