History and Diagnostic Value of Antibodies to Citrullinated Proteins in Rheumatoid Arthritis

Rheumatoid arthritis is a chronic inflammatory joint disease characterized by the presence of autoantibodies. The best known autoantibody is the rheumatoid factor. Another group of antibodies directed against citrullinated epitopes is proven to be more specific for rheumatoid arthritis. This review gives an overview of the history of the different anti-citrullinated protein antibody detection methods and their diagnostic and prognostic properties in RA.

Melanoma inhibitory activity, a biomarker related to chondrocyte anabolism, is reversibly suppressed by proinflammatory cytokines in rheumatoid arthritis

OBJECTIVE

In mice, melanoma inhibitory activity (MIA) is a chondrocyte-specific molecule with similar regulation to collagen type II. As MIA is a small secreted protein, its value as cartilage biomarker in human inflammatory arthritis was assessed.

METHODS

MIA tissue distribution was studied by quantitative PCR and immunohistochemistry. The regulation of MIA production was studied in vivo in rheumatoid arthritis (RA) (n = 37) and spondyloarthritis (SpA) (n = 30) synovial fluid (SF), and in vitro in alginate embedded human chondrocytes. Therapeutic modulation of serum MIA was evaluated during tumour necrosis factor (TNF)alpha and interleukin (IL)1 blockade in RA.

RESULTS

MIA was primarily expressed by chondrocytes in the human joint. SF MIA levels were lower in RA than in SpA despite similar levels of overall synovial inflammation. Further analysis indicated that these levels were inversely correlated with the degree of joint inflammation in RA, but not in SpA, and that the levels of TNFalpha and IL1beta were significantly increased in RA versus SpA. Accordingly, these proinflammatory cytokines suppressed MIA mRNA and protein in cultured chondrocytes. This suppression was paralleled by suppression of cartilage anabolism as assessed by collagen type 2 and aggrecan mRNA. Treatment of patients with RA with TNF blockade or IL1 blockade induced an increase of serum MIA levels.

CONCLUSION

The decreased levels of MIA in the inflamed RA joint and the coregulation of MIA and cartilage matrix molecules by proinflammatory cytokines indicate that joint inflammation in RA not only drives accelerated cartilage degradation but also suppresses cartilage anabolism. This inflammation-driven suppression is reversible in vivo.

Exposure to nuclear antigens contributes to the induction of humoral autoimmunity during tumour necrosis factor alpha blockade

OBJECTIVE

Type I interferons and apoptotic particles contribute to antinuclear autoimmunity in experimental models. This study assessed whether similar mechanisms contribute to break peripheral B-cell tolerance in humans by studying the induction of antinuclear antibodies by tumour necrosis factor blockade in spondyloarthritis.

METHODS

40 spondyloarthritis patients treated with infliximab or etanercept and 20 renal cell carcinoma patients treated with sorafenib were studied. Serum antinucleosome IgM and nucleosomes were measured by ELISA. Type I interferon serum activity was measured using a functional reporter cell assay. Synovial apoptosis was assessed by terminal transferase nick end-labelling (TUNEL) assay and anti-active caspase-3 immunostaining. Complement was measured by nephelometry.

RESULTS

Despite a similar clinical improvement and reduction of synovial inflammation, antinucleosome IgM were induced by infliximab but not etanercept. This induction did not correlate with type I interferon activity, which was transiently downmodulated by infliximab but persistently upregulated by etanercept. In contrast, antinucleosome IgM levels did correlate with serum nucleosome levels, which were significantly upregulated by infliximab but not by etanercept treatment. This increase in serum nucleosome levels was not directly related to massive cell death, but rather to a decrease of complement 3 and 4 serum levels during infliximab treatment.

CONCLUSION

Infliximab and etanercept have a differential effect on both type I interferon activity and nucleosome levels. Only elevated serum nucleosomes relate to the induction of antinucleosome antibodies after infliximab treatment.

Anti-citrullinated protein/peptide antibodies (ACPA) in rheumatoid arthritis: specificity and relation with rheumatoid factor

Anti-citrullinated protein/peptide antibodies (ACPA) are highly specific and sensitive markers for rheumatoid arthritis (RA). For instance, for the anti-CCP2 assay, sensitivities ranging from 55% to 80% and specificities ranging from 90% to 98% have been reported. Despite their high specificity, recent reports have suggested that ACPA may be found in some patients with other rheumatic autoimmune diseases, including psoriatic arthritis, systemic lupus erythematosus and Sjögren's syndrome. Also, the differences between the classical rheumatoid factor (RF) and ACPA, as well as the complementarity between both tests have recently been demonstrated more clearly. Indeed, both antibody systems have a different association with specific RA features like extra-articular manifestations, a different association with the HLA shared epitope and, behave differently following anti-TNF therapy.

The effect of TNFalpha blockade on the antinuclear antibody profile in patients with chronic arthritis: biological and clinical implications

Since the first proof of efficacy of TNFalpha blockade, both the number of patients treated worldwide and the number of indications for treatment with TNFalpha blockers have grown steadily. Surprisingly, the profound immunomodulation induced by anti-TNFalpha therapy is associated with a relatively low incidence of immune-related complications such as lupus-like syndromes and demyelinating disease. This contrasts sharply with the prominent induction of autoantibodies such as antinuclear antibodies (ANA) and anti-dsDNA antibodies during TNFalpha blockade. Although this phenomenon has been recognized for several years, the clinical and biological implications are not yet fully understood. In this review, recent studies analysing the effect of TNFalpha blockade (infliximab and etanercept) on the ANA profile in autoimmune arthritis will be discussed. Taken together, these reports indicate that the prominent ANA and anti-dsDNA autoantibody response is 1) not a pure class effect of TNFalpha blockers, 2) independent of the disease background, 3) largely restricted to the induction of short-term IgM anti-dsDNA antibodies, and 4) not associated with other serological or clinically relevant signs of lupus. Nevertheless, a careful follow-up of patients treated with TNFalpha blockers remains mandatory, including monitoring for lupus-like characteristics.

Altered gut transcriptome in spondyloarthropathy

BACKGROUND

Intestinal inflammation is a common feature of spondyloarthropathy (SpA) and Crohn's disease. Inflammation is manifested clinically in Crohn's disease and subclinically in SpA. However, a fraction of patients with SpA develops overt Crohn's disease.

AIMS

To investigate whether subclinical gut lesions in patients with SpA are associated with transcriptome changes comparable to those seen in Crohn's disease and to examine global gene expression in non-inflamed colon biopsy specimens and screen patients for differentially expressed genes.

METHODS

Macroarray analysis was used as an initial genomewide screen for selecting a comprehensive set of genes relevant to Crohn's disease and SpA. This led to the identification of 2625 expressed sequence tags that are differentially expressed in the colon of patients with Crohn's disease or SpA. These clones, with appropriate controls (6779 in total), were used to construct a glass-based microarray, which was then used to analyse colon biopsy specimens from 15 patients with SpA, 11 patients with Crohn's disease and 10 controls.

RESULTS

95 genes were identified as differentially expressed in patients with SpA having a history of subclinical chronic gut inflammation and also in patients with Crohn's disease. Principal component analysis of this filtered set of genes successfully distinguished colon biopsy specimens from the three groups studied. Patients with SpA having subclinical chronic gut inflammation cluster together and are more related to those with Crohn's disease.

CONCLUSION

The transcriptome in the intestine of patients with SpA differs from that of controls. Moreover, these gene changes are comparable to those seen in patients with Crohn's disease, confirming initial clinical observations. On the basis of these findings, new (genetic) markers for detection of early Crohn's disease in patients with SpA can be considered.

Synovial inflammation does not change in the absence of effective treatment: implications for the use of synovial histopathology as biomarker in early phase clinical trials in rheumatoid arthritis

OBJECTIVES

To determine the impact on synovial histopathology of changes in clinical disease activity in the absence of effective treatment.

METHODS

Twelve patients with active RA not receiving effective treatment were studied over a 14 week period. Synovial biopsy specimens obtained at baseline and week 14 were analysed by histology and immunohistochemistry.

RESULTS

Over the course of 14 weeks, there was a trend towards a decrease of the DAS28, with 7/12 patients being good or moderate DAS28 responders despite the absence of effective treatment. Patients' assessment of global disease activity and swollen joint count both decreased significantly. Histologically, there was a decrease of lining layer hyperplasia and lymphoid aggregates, a similar trend for vascularity, but there was no effect on global synovial infiltration. Accordingly, there was no decrease of the cellular infiltration with T lymphocytes (CD3, CD4, CD8), B lymphocytes (CD20), plasma cells (CD38), dendritic cells (CD1a, CD83), and even an increase of CD163+ sublining macrophages, with a similar trend for CD68+ sublining macrophages. The changes in DAS28 scores in these patients did not correlate with changes in histological variables, with the exception of an inverse correlation with plasma cells. Remarkably, even in the DAS28 responders, no significant changes in synovial inflammatory infiltration were noted.

CONCLUSIONS

Despite variations in global disease activity, synovial inflammatory infiltration did not change significantly in the absence of effective treatment. The lack of a placebo effect on synovial markers of treatment response such as sublining macrophages can facilitate conclusive early phase trials with small numbers of patients with RA.

Cyclodextrin polysulphates repress IL-1 and promote the accumulation of chondrocyte extracellular matrix

OBJECTIVE

To evaluate the influence of cyclodextrin polysulphate (CDPS) on the extracellular matrix (ECM) metabolism of human articular cartilage chondrocytes.

METHODS

Isolated chondrocytes from femoral condyle cartilage of human knee joints were cultured in gelled alginate to maintain their differentiated phenotype. During 1 week of culture, the cells were exposed to different concentrations of CDPS. Synthesis of aggrecans was investigated in these cultures after using Na(2)(35)SO(4) as a radioactive precursor during the last 24h of culture. The artificial matrix was then solubilised with Na-citrate and newly synthesised aggrecan aggregates, accumulated during culture, were liberated and assayed. The isolated chondrocytes were labelled with antibodies against aggrecan and type II collagen to analyse the ECM molecules in the cell-associated matrix (CAM). Plasma membrane levels of receptors for insulin-like growth factor-1 (IGF-1RI) and for interleukin-1 (IL-1RI and IL-1RII), as well as levels of IGF-1, IL-1alpha and -beta were determined after the cells had been permeabilized and stained with the appropriate antibodies. The release of IL-6 in the culture media was used as a variable reflecting auto/paracrine IL-1 activity of the cells in different experimental conditions.

RESULTS

CDPS significantly increased total (35)S-incorporation rates in ECM aggrecan. When compared with controls, CDPS-treated chondrocytes expressed significantly higher CAM aggrecan and type II collagen levels. As plasma membrane-bound IGFR1 and intracellular IGF-1 levels remained unchanged, this increase in accumulated CAM compounds may have resulted from suppressed catabolic activities by the chondrocytes in culture. CDPS-treated cells expressed significantly lower amounts of intracellular IL-1alpha and -beta levels. Plasma membrane-bound IL-1RI and decoy IL-1RII remained unchanged. beta-cyclodextrin-treated chondrocytes released significantly less IL-6 in the supernatant culture media.

CONCLUSION

CDPS is a novel polysulfated polysaccharide showing cartilage structure modifying effects in vitro as it improves the synthesis of aggrecan and the accumulation of CAM macromolecules. This effect probably resulted in part from the downregulation of IL-1.

Effect of age on prevalence of anticitrullinated protein/peptide antibodies in polyarticular juvenile idiopathic arthritis

OBJECTIVES

Anticitrullinated protein/peptide antibodies (ACPA) have an excellent diagnostic performance for rheumatoid arthritis (RA). Despite similarities between RA and polyarticular juvenile idiopathic arthritis (JIA), the prevalence of ACPA in polyarticular JIA is low. We wanted to evaluate the influence of age, disease duration and total immunoglobulin G (IgG) concentration on ACPA positivity in this cohort.

METHODS

Patients with JIA were classified according to age and International League of Associations for Rheumatology classification. Sixty-one JIA patients aged less than 16 yr were included and classified as polyarticular JIA (poly JIA <16; n=23) or non-polyarticular JIA (n=38). In addition, a group of 21 polyarticular JIA patients, aged more than 16 yr (poly JIA >16) and a group of 51 RA patients were included. Antibodies to the synthetic citrullinated peptides pepA and pepB were detected by line immunoassay and antibodies to cyclic citrullinated peptides (CCP2) by enzyme-linked immunosorbent assay. Serum IgG was measured by fixed-time immunonephelometry.

RESULTS

No ACPA reactivity was observed in the non-polyarticular group. In poly JIA <16, only 1/23 had anti-CCP2 antibody, whereas in poly JIA >16 patients a significantly higher fraction was detected (6/21). All but one of the anti-CCP2 reactive patients were rheumatoid factor (RF) positive. Assessing anti-CCP2 antibody concentration as a continuous variable, significantly higher titres were found in poly JIA >16 compared with poly JIA <16. No correlation between anti-CCP2 concentration and total IgG was detected. Four patients demonstrated immunoreactivity against pepA and pepB; all of them were anti-CCP2 reactive, poly JIA >16 patients.

CONCLUSIONS

ACPA are present in low prevalence in polyarticular JIA and are particularly found in the RF-positive subset. With age, a significant increase in anti-CCP2 positivity is observed in polyarticular JIA patients.

Characterisation of human knee meniscus cell phenotype

OBJECTIVE

Studies on the biology of the human meniscus cell are scarce. The objective of our studies was to assess survival/proliferation of human meniscus cells in different culture conditions and to characterize the extracellular matrix (ECM) produced by these cells in these artificial environments. The composition of this ECM offers a variable to define the distinct meniscus cell phenotype.

MATERIALS AND METHODS

Human meniscus cells were isolated enzymatically from visually intact lateral and medial knee menisci. Cells were cultured in monolayer conditions or in alginate gel. The composition of the cell-associated matrix (CAM) accumulated by the isolated cells during culture was investigated and compared to the CAM of articular chondrocytes cultured in alginate using flow cytometry with fluorescein isothiocyanate-conjugated monoclonal antibodies against type I collagen, type II collagen and aggrecan. Additional cell membrane markers analysis was performed to further identify the different meniscus cell populations in the alginate culture conditions and meniscus tissue sections. Proliferation was analyzed using the Hoechst 33258 dye method. In some experiments, the effect of TGFbeta1 on some of these variables was investigated.

RESULTS

The CAM of monolayer cultured meniscus cells is composed of high amounts of type I and II collagen and low amounts of aggrecan. A major population of alginate cultured meniscus cells on the other hand synthesized a CAM containing high amounts of type I collagen, low amounts of type II collagen and high amounts of aggrecan. This population is CD44+CD105+CD34-CD31-. In contrast, a minor cell population in the alginate culture did not accumulate ECM and was mainly CD34+. The CAM of alginate cultured articular chondrocytes is composed of low amounts of type I collagen, high amounts of type II collagen and aggrecan. The expression of aggrecan and of type II collagen was increased by the addition of TGFbeta1 to the culture medium. The proliferation of meniscus cells is increased in the monolayer culture conditions. Cell numbers decrease slightly in the alginate culture, but can be increased after the addition of TGFbeta1.

CONCLUSION

These results demonstrate that the human meniscus is populated by different cell types which can be identified by a distinct CAM composition and membrane marker expression. Unlike the monolayer culture conditions, the alginate culture conditions appear to favor a more fibrochondrocyte-like cell accumulating a CAM resembling the native tissue composition. This CAM composition is distinctly different from the CAM composition of phenotypically stable articular cartilage chondrocytes cultured in the same alginate matrix.

CARD15 gene polymorphisms in patients with spondyloarthropathies identify a specific phenotype previously related to Crohn's disease

BACKGROUND

The association between spondyloarthropathy and Crohn's disease is well known. A risk for evolution to Crohn's disease has already been shown in the subgroup of patients with spondyloarthropathy associated with chronic gut inflammation.

OBJECTIVE

To investigate whether the reported polymorphisms in the CARD15 gene, a susceptibility gene for Crohn's disease, are associated with the presence of preclinical intestinal inflammation observed in spondyloarthropathies.

METHODS

104 patients with spondyloarthropathies were studied. All underwent ileocolonoscopy with biopsies between 1983 and 2004. The prevalence of three single nucleotide polymorphisms in the CARD15 gene (R702W, G908R, and 1007fs) was assessed using restriction fragment length polymorphism-polymerase chain reaction (RFLP-PCR); the patients were compared with an ethnically matched Crohn's disease population and a control population.

RESULTS

The carrier frequency of R702W, G908R, or 1007fs variants in the spondyloarthropathy populations (20%) was similar to the control population (17%), but increased to 38% in the spondyloarthropathy subgroup with chronic gut inflammation. This frequency was significantly higher than in the other spondyloarthropathy subgroups (p = 0.001) or the control group (p = 0.006), but not different from the Crohn's disease group (49%) (NS). This indicates that CARD15 polymorphisms are associated with a higher risk for development of chronic gut inflammation.

CONCLUSIONS

CARD15 gene polymorphisms clearly identify a subgroup of patients with spondyloarthropathies associated with chronic intestinal inflammation.

CARD15 polymorphisms are associated with anti-Saccharomyces cerevisiae antibodies in caucasian Crohn's disease patients

Carriage of CARD15 gene polymorphisms and the serological marker anti-Saccharomyces cerevisiae antibodies (ASCA) are two markers for Crohn's disease (CD). Similar phenotypes have been associated with both markers. In the present study we analysed whether both markers were associated with each other and, if so, whether this association could be explained by a direct link or by an indirect association with those phenotypes. Therefore, we included 156 consecutive Caucasian CD patients and assessed the prevalence of the three common single nucleotide polymorphisms in the CARD15 gene. Serum samples were analysed for IgA and IgG ASCA by ELISA. CD patients with CARD15 polymorphisms were more frequently ASCA positive (OR 2.7 (1.4-5.2); P = 0.002) and had higher titres for ASCA IgA (P = 0.005) and ASCA IgG (P < 0.001) compared to patients carrying the wild type polymorphisms. Multivariate analysis demonstrated that this association was independent from ileal disease, penetrating disease and stricturing disease, the need for resective bowel surgery, familial cases, smoking habits and early age at onset. Homozygotes or compound heterozygotes for CARD15 polymorphisms had significantly more frequent ASCA positivity compared to single heterozygotes (OR 9.1 (1.1-74.2), P(c) (corrected P-value) = 0.030). These data indicate that there is a significant association between the carriage of CARD15 polymorphisms and ASCA, independent of the described phenotypes. Moreover, ASCA positivity is more frequent in CD patients carrying 2 CARD15 polymorphisms compared to single heterozygotes.

Involvement of neurotrophins and their receptors in spondyloarthritis synovitis: relation to inflammation and response to treatment

OBJECTIVE

To investigate whether expression of the four members of the neurotrophin (NT) family and their four corresponding receptors is related to synovial inflammation in patients with spondyloarthritis (SpA).

MATERIAL AND METHODS

Synovial fluid (SF) and serum NTs and their receptors were measured by ELISA. Immunohistochemistry was used for synovial tissue biopsy specimens from patients with SpA, rheumatoid arthritis, and osteoarthritis (OA). In SpA synovium, immunoreactivity of the receptors trkA and NGFRp75 was also assessed before and after 12 weeks of treatment with the monoclonal anti-tumour necrosis factor alpha antibody, infliximab.

RESULTS

mRNA transcripts of all NTs and receptors were expressed in the inflamed synovium. At the protein level, brain derived neurotrophic factor and NT-3 were significantly higher in the SF of patients with SpA than in those with OA. In contrast, ELISA of serum samples showed that the highest member in SpA was NT-4. Immunohistochemistry demonstrated that the NT receptors trkA and NGFRp75 were highly expressed in the inflamed synovium of patients with SpA, correlating with vascularity and lymphoid aggregates, respectively. Additionally, immunoreactivity of both receptors was significantly decreased after infliximab treatment.

CONCLUSIONS

NTs and their receptors are expressed in inflamed peripheral joints of patients with SpA. Their expression is not constitutive but related to inflammation and they may be involved in the local disease processes.

Functional haplotypes of PADI4: relevance for rheumatoid arthritis specific synovial intracellular citrullinated proteins and anticitrullinated protein antibodies

BACKGROUND

Haplotypes of PADI4, encoding for a citrullinating enzyme, were associated with rheumatoid arthritis in a Japanese population. It was suggested they were related to the presence of anticitrullinated protein antibodies (ACPA).

OBJECTIVE

To explore the relation between PADI4 haplotypes, the presence of rheumatoid arthritis specific intracellular citrullinated proteins in synovial membrane, and serum ACPA titres.

METHODS

Synovial biopsies and peripheral blood samples were obtained in 59 patients with rheumatoid arthritis. Synovial intracellular citrullinated proteins were detected by immunohistochemistry. Serum ACPA titres were measured by anti-CCP2 ELISA. PADI4 haplotypes were determined by direct sequencing of the four exonic PADI4 single nucleotide polymorphisms.

RESULTS

PADI4 haplotype frequencies and the presence of synovial intracellular citrullinated proteins and ACPA were comparable with previous studies. There was no significant association between PADI4 haplotype 1 or 2 and the presence of synovial intracellular citrullinated proteins, although these proteins were associated with higher serum ACPA. There was no correlation between PADI4 haplotypes and serum ACPA, either by continuous analysis using the titres or by dichotomous analysis using the diagnostic cut off. Further analyses in homozygotes for haplotype 1 or 2 or in heterozygotes (1/2) also failed to show an association between PADI4 polymorphisms and ACPA. This contrasted with the clear association between ACPA levels and HLA-DR shared epitope.

CONCLUSIONS

The link between synovial intracellular citrullinated proteins and ACPA emphasises the role of deimination of synovial proteins in rheumatoid arthritis, but the biological relevance of the PADI4 haplotypes for this autoimmune process is questionable, at least in a European population.

Anti-citrullinated peptide antibodies may occur in patients with psoriatic arthritis

BACKGROUND

Anti-cyclic citrullinated peptide (anti-CCP) antibodies are considered highly specific markers of rheumatoid arthritis. Despite the high specificity of the test, anti-CCP antibodies have also been observed in psoriatic arthritis.

OBJECTIVE

To determine the frequency of anti-CCP antibodies in psoriatic arthritis and to describe the clinical characteristics of such patients.

METHODS

Serum samples from 192 patients with psoriatic arthritis were analysed for anti-CCP antibodies. A previously defined cut off point was applied at a specificity level of > or =98.5% (42 U/ml). Antibodies against pepA and pepB (two synthetic citrullinated peptides) were determined on samples containing anti-CCP antibodies by line immune assay. The swollen joint count and the numbers of affected joints (present or past) were recorded. Clinical features were noted and if available radiographs of hands and feet were scored for erosions. Rheumatoid factor was determined in all samples.

RESULTS

Anti-CCP antibodies were found in 15 patients (7.8%); 13 of 15 anti-CCP2 positive samples were also positive for anti-pepA or pepB antibodies. The prevalence of anti-CCP antibodies was higher than expected in view of the highly specific cut off applied in the test. Detailed analysis of the clinical and radiological features makes it improbable that the high prevalence of anti-CCP antibodies resulted solely from concomitant psoriasis and rheumatoid arthritis or from misclassification.

CONCLUSIONS

Anti-CCP antibodies may be present in patients with psoriatic arthritis. Although some of the present cohort could have had psoriasis with concomitant rheumatoid arthritis, a proportion at least had the typical characteristics of psoriatic arthritis as the primary diagnosis.

A dose adjustment in patients with rheumatoid arthritis not optimally responding to a standard dose of infliximab of 3 mg/kg every 8 weeks can be effective: a Belgian prospective study

OBJECTIVES

To analyse the effect of a dose increase in patients with severe rheumatoid arthritis (RA) with insufficient clinical response to 3 mg/kg infliximab every 8 weeks.

METHODS

Patients suffering from active refractory RA despite methotrexate, were treated with i.v. infusions of infliximab (3 mg/kg) on week 0, 2, 6 and every 8 weeks thereafter. Based on the clinical judgement at week 22, patients received a dose increase of 100 mg from week 30 on. The American College of Rheumatology (ACR) core set for disease activity measures was regularly assessed.

RESULTS

Five hundred and eleven RA patients were included. At week 22, 61.4, 34 and 14.1% of all patients met ACR 20, ACR 50 and ACR 70 criteria, respectively, and 6.1% of patients were in remission. A low swollen joint count at baseline was correlated with improvement at week 22 for ACR 20 (P < 0.06), ACR 50 (P < 0.06) and ACR 70 (P < 0.005). The change in HAQ score between weeks 0 and 22 was predictive for response at week 54 (P < 0.01). The dose of infliximab was increased by 100 mg in 22% of the patients. Most baseline values of patients requiring dose increase were higher (P < or = 0.001) than the baseline values of the remaining patients. Increasing the dose of infliximab by one vial from week 30 on could circumvent the partial loss of response in these patients.

CONCLUSION

Infliximab use in this large out-patient cohort resulted in a significant clinical improvement. A subgroup that partially lost response during the first 22 weeks could regain response by adding 100 mg of infliximab to the subsequent doses. Due to the current study design, however, a regression to the mean like effect could not be ruled out.

Rheumatoid factor and anticitrullinated protein antibodies in rheumatoid arthritis: diagnostic value, associations with radiological progression rate, and extra-articular manifestations

BACKGROUND

Autoantibodies such as rheumatoid factor (RF) and anticitrullinated protein antibodies can be detected in rheumatoid arthritis (RA) sera.

OBJECTIVE

To determine the diagnostic values of RF, anticitrullinated protein antibodies, and the shared epitope (SE), and their associations with radiological progression rates and extra-articular manifestations.

METHODS

Population 1 consisted of sera from 315 patients, consecutively sent for detection of anticitrullinated protein antibodies, of which 264 were used to determine the sensitivity and specificity of RF and of antibodies against three synthetic citrullinated peptides: peptide A (pepA), peptide B (pepB), and CCP2. Population 2 consisted of sera from 180 longstanding RA patients and was used to determine associations of RA associated antibodies and the SE with radiological progression rates and extra-articular manifestations. Antibodies to pepA and pepB were detected by line immunoassay, and antibodies to CCP2 by ELISA. HLA Class II typing was performed by LiPA.

RESULTS

In population 1, we defined adapted cut offs corresponding to a specificity of >/=98.5%. This yielded the following sensitivities: RF 12.8%; anti-pepA antibodies 63.6%; anti-pepB antibodies 54.2%; and anti-CCP2 antibodies 73.7%. In population 2, significant differences in radiological progression rates were found between positive and negative patients for different RA antibodies and the SE. RF, but not anticitrullinated protein antibodies or the SE, were more frequent in patients with extra-articular manifestations.

CONCLUSION

A valid comparison of RA associated antibodies shows superior sensitivity of the anticitrullinated protein antibodies compared with RF. The presence of RA associated antibodies and the SE are indicative for poorer radiological outcome, and presence of extra-articular manifestations is associated with RF but not with anticitrullinated protein antibodies.

Histological evidence that infliximab treatment leads to downregulation of inflammation and tissue remodelling of the synovial membrane in spondyloarthropathy

OBJECTIVE

To confirm and extend the immunopathological evidence of effects of infliximab on the synovium in active spondyloarthropathy.

METHODS

Synovial biopsies obtained in patients with spondyloarthropathy at baseline and week 12 were stained and scored by two independent observers. Two study populations were evaluated: I, a cohort of 10 patients treated with 5 mg/kg infliximab at week 0, 2, and 6, plus three placebo treated patients; and II, a pooled cohort of 20 patients fulfilling identical inclusion and exclusion criteria and treated with the same loading dose regimen.

RESULTS

In study population I, treatment with infliximab induced reduction in synovial lining layer thickness (p = 0.015), endothelial activation (E-selectin, p = 0.034), and inflammatory cell infiltration with neutrophils (p = 0.041), macrophages (p = 0.034), and T cells (p = 0.026), but not with B cells and plasma cells; no such trends were observed in the placebo treated patients. Besides confirming the highly significant downregulation of inflammation, analysis of cohort II showed structural changes such as normalisation of lining layer thickness (p = 0.030), reduction in the number of blood vessels (p = 0.039), and downregulation of follicular organisation (p = 0.050). No differences in histopathological response were observed between spondyloarthropathy subtypes.

CONCLUSIONS

Profound immunomodulatory changes in the synovium parallel the clinical benefit in patients with spondyloarthropathy treated with infliximab, independently of the subtype. The study provides histological evidence that TNF alpha blockade not only downregulates inflammation but also leads to tissue remodelling.

Specific antinuclear antibodies are associated with clinical features in systemic lupus erythematosus

OBJECTIVES

To study associations between antinuclear antibodies (ANA) and signs/symptoms in patients with systemic lupus erythematosus (SLE).

METHODS

A consecutive cohort of 289 patients with SLE was included; 235 fulfilled ACR criteria for SLE and were further analysed. ANA profiles were determined by line immunoassay and by indirect immunofluorescence on Crithidia luciliae. An extensive list of signs/symptoms was evaluated.

RESULTS

Five clusters of antibodies were defined by cluster analysis: 1-antibodies to SmB, SmD, RNP-A, RNP-C, and RNP-70k; 2-antibodies to Ro52, Ro60, and SSB; 3, 4, and 5-antibodies to ribosomal P, histones and dsDNA, respectively. Significant associations (p< or =0.01) were found between anti-RNP-70k, anti-RNP-A, anti-RNP-C and Raynaud's phenomenon, between anti-RNP-A, anti-RNP-70k and leucopenia, and between anti-RNP-A, anti-RNP-C and a lower prevalence of urine cellular casts. Anti-SSA, anti-SSB were associated with xerostomia, and anti-SSB with pericarditis. Antibodies to ribosomal P were associated with haemolytic anaemia, leucopenia, and alopecia. Patients with anti-dsDNA antibodies had a higher risk for cellular casts and a lower risk for photosensitivity. Antihistone antibodies were associated with arthritis.

CONCLUSIONS

In a large and consecutive cohort of patients with SLE, clusters of antibodies were identified. Previously reported associations of antibodies with symptoms were confirmed and new associations found.

Tumour necrosis factor alpha independent disease mechanisms in rheumatoid arthritis: a histopathological study on the effect of infliximab on rheumatoid nodules

BACKGROUND

It has been suggested that the immunopathology of rheumatoid nodules parallels that of inflamed synovium in rheumatoid arthritis (RA).

OBJECTIVE

To analyse the effect of infliximab on the immunopathology of rheumatoid nodules in order to provide new insights into the relationship between synovial inflammation and rheumatoid nodules.

MATERIALS AND METHODS

Nodules were present at baseline in six patients with RA and after infliximab treatment in five patients, including paired nodules before and after treatment in three patients. In one patient, the nodule appeared during treatment. Paraffin sections were used for histological analysis. Frozen sections were stained by immunohistochemistry for cellular markers (CD3, CD4, CD8, CD16, CD20, CD68), blood vessels (CD146, vWF, alphavbeta3), and adhesion molecules (E-selectin, VCAM-1, ICAM-1).

RESULTS

No manifest immunopathological differences were found between the nodules before and after infliximab treatment. All nodules depicted the classical structure with a central necrotic zone, surrounding the palisade layer, and an outer connective tissue zone. Immunohistochemistry showed the presence of CD68+ and CD16+ macrophages in the palisade and the connective tissue zone, as well as a small number of CD3+, CD4+ T lymphocytes in the perivascular areas. Small vessels were seen in the connective tissue and were sometimes positive for the neovascularisation marker alphavbeta3. They expressed no VCAM-1, E-selectin weakly, but ICAM-1 strongly. ICAM-1 was also strongly expressed on palisade cells.

CONCLUSIONS

Despite an improvement of articular symptoms, infliximab treatment had no distinct effect on the histopathology of rheumatoid nodules, suggesting that different pathogenetic mechanisms mediate the two disease manifestations in RA.

Technical validation of cDNA based microarray as screening technique to identify candidate genes in synovial tissue biopsy specimens from patients with spondyloarthropathy

OBJECTIVES

To validate the use of cDNA based microarray on synovial biopsies by analysing the experimental variability due to amplification of RNA, reproducibility of the assay, heterogeneity of the tissue, and statistical analysis.

METHODS

Total RNA was extracted from three spondyloarthropathy (SpA) and three osteoarthritis (OA) synovial tissue biopsy specimens and from the peripheral blood mononuclear cells (PBMC) of four healthy donors. Exponential RNA amplification by SMART-PCR was compared with linear amplification. Reproducibility was tested by comparing different microarray systems and by performing duplicate experiments. Sample heterogeneity was assessed by comparing overall gene expression profiles, histopathology, and analysis of genes expressed in the synovium and normal PBMC. Statistical analysis using t test and Bonferroni adjustment was verified by permutation of class labels.

RESULTS

Gene expression was concordant in 12/14 (86%) cytokine/chemokine genes between both microarrays and different RNA amplification systems. When one microarray system was used, expressed genes were 78-95% concordant in duplicate experiments. Gene expression profiles had a higher degree of similarity between SpA synovium than between PBMC or OA synovium despite clear histopathological differences between synovial samples. Comparison of SpA synovium with OA synovium and with PBMC yielded 11 and 18 expressed transcripts, respectively; six were shared in both comparisons. Permutations of SpA and OA samples yielded only one expressed gene in 19 comparisons.

CONCLUSIONS

These data provide evidence that microarrays can be used for analysis of synovial tissue biopsies with high reproducibility and low variability of the generated gene expression profiles.

Rheumatoid factor, but not anti-cyclic citrullinated peptide antibodies, is modulated by infliximab treatment in rheumatoid arthritis

OBJECTIVES

To analyse the effect of infliximab on IgM rheumatoid factor (RF) and anti-cyclic citrullinated peptide (CCP) antibodies, and determine whether baseline autoantibody titres (IgM RF and anti-CCP antibodies) are associated with changes in acute phase reactants.

PATIENTS AND METHODS

62 patients with refractory RA were treated with infliximab combined with methotrexate. At baseline and week 30, serum samples were tested for IgM RF by two agglutination assays, and for anti-CCP antibodies by an ELISA. Percentage change in C reactive protein (CRP) and erythrocyte sedimentation rate (ESR) was calculated.

RESULTS

At baseline and week 30 RF titres were reduced significantly during infliximab treatment (p<0.001 and p = 0.038, respectively), whereas anti-CCP antibodies were unchanged (p = 0.240). Baseline IgM RF titres, but not anti-CCP antibodies, correlated inversely with changes in CRP and ESR during treatment. Patients with a marked decrease in acute phase reactants had lower IgM RF titres than those with a smaller decrease in CRP and ESR; no significant differences were found for anti-CCP antibodies.

CONCLUSION

The differential effect of infliximab treatment on IgM RF and anti-CCP antibodies, and the different predictive value on changes in acute phase reactants during infliximab treatment support the existing evidence that RF and anti-CCP antibodies are independent autoantibody systems in RA.

Colon mucosa of patients both with spondyloarthritis and Crohn's disease is enriched with macrophages expressing the scavenger receptor CD163

BACKGROUND

Crohn's disease is associated with an increased number of macrophages in ileal and colonic mucosa. Data on macrophages in gut mucosa of patients with spondyloarthritis (SpA) are scarce.

OBJECTIVE

To investigate macrophages and other antigen presenting cells in gut mucosa from patients with SpA and Crohn's disease, given the relationship between both entities.

METHODS

Biopsy specimens from patients with SpA, Crohn's disease, ulcerative colitis, and from controls were immunohistochemically stained with different markers for macrophages and dendritic cells. Slides were scored semiquantitatively on a four point scale.

RESULTS

SpA and Crohn's disease were associated with large numbers of CD68+ macrophages. Colon mucosa of both patients with SpA and Crohn's disease, but not ulcerative colitis, showed increased numbers of macrophages expressing the scavenger receptor CD163.

CONCLUSIONS

Macrophages expressing the scavenger receptor CD163 are increased in colonic mucosa in SpA and in Crohn's disease, highlighting the relationship between these entities. The increased number of CD163+ macrophages in colon mucosa of patients with SpA suggests this is another argument for a role of macrophage scavenger receptors in this group of diseases.

Physiological levels of hydrocortisone maintain an optimal chondrocyte extracellular matrix metabolism

OBJECTIVE

To investigate the effects of physiological doses of hydrocortisone on synthesis and turnover of cell associated matrix (CAM) by human chondrocytes obtained from normal articular cartilage.

METHODS

Human articular cartilage cells were obtained from visually intact cartilage of the femoral condyles of five donors and maintained in culture for one week to reach equilibrium in accumulated CAM compounds. 0, 0.05, 0.20, and 1.0 micro g/ml hydrocortisone was added to the nutrient media during the entire culture period. Cells were liberated and levels of CAM aggrecan, type II collagen, and fibronectin, of intracellular IGF-1, IL1alpha and beta, and of their respective plasma membrane bound receptors IGFR1, IL1RI, and the decoy receptor IL1RII, were assayed by flow cytometry.

RESULTS

In comparison with controls, hydrocortisone treated chondrocytes, at all concentrations, expressed significantly higher plasma membrane bound IGFR1. Intracellular IGF-1 levels remained unchanged. Together with these changes, reflecting an increased ability to synthesise extracellular matrix (ECM) macromolecules, hydrocortisone treated cells expressed significantly higher amounts of the plasma membrane bound decoy IL1RII. Concurrently, intracellular IL1alpha and beta levels and membrane bound IL1RI were down regulated. Levels of CAM aggrecan, type II collagen, and fibronectin were significantly up regulated in the chondrocytes treated with hydrocortisone.

CONCLUSION

0.05 micro g/ml hydrocortisone treated chondrocytes had decreased catabolic signalling pathways and showed an enhanced ability to synthesise ECM macromolecules. Because IL1 activity was decreased and the expression of IL1RII decoy receptor enhanced, more of the ECM macromolecules produced remained accumulated in the CAM of the chondrocytes. The effects were obtained at doses comparable with physiological plasma levels of hydrocortisone in humans.

Homeostasis of the extracellular matrix of normal and osteoarthritic human articular cartilage chondrocytes in vitro

OBJECTIVE

In normal articular cartilage cells, the IGFRI/insulin-like growth factor 1 (IGF-1) autocrine pathway was shown to overrule the catabolic effects of the IL-1/IL-1RI pathway by up-regulation of the IL-1RII decoy receptor. The activity of the IGF-1/IGFR1 and IL-1/IL-1R pathways, and of the IL-1RII control mechanism in the synthesis and turnover of the extracellular matrix (ECM) by chondrocytes from normal and osteoarthritic (OA) articular cartilage was compared in order to identify possible therapeutic targets of this disease.

METHODS

Phenotypically stable human articular cartilage cells were obtained from normal and OA cartilage of the same knee showing focal OA. The cells were cultured in alginate beads over 1 week to re-establish the intracellular cytokine and growth factors, to reexpress the respective plasma membrane receptors and to reach equilibrium in accumulated cell-associated matrix (CAM) compounds. Following liberation of the cells from the alginate beads, the levels of cell-associated matrix (CAM) aggrecan, type II collagen and fibronectin, of intracellular IGF-1, IL-1alpha and beta and of their respective plasma membrane-bound receptors, IGFR1, IL-1RI and the decoy receptor IL-1RII, were assayed using flow cytometry.

RESULTS

Coordinated production and accumulation of CAM aggrecan and type II collagen under the effect of the IGFR1/IGF-1 autocrine pathway-as documented for chondrocytes from healthy controls-was absent when the chondrocytes had been obtained from OA joints. When compared with cells obtained from normal tissues, chondrocytes from fibrillated OA cartilage expressed significantly higher intracellular IGF-1 levels and plasma membrane-bound IGFR1. At the same time, significantly higher intracellular IL-1alpha and beta levels and upregulated plasma membrane-bound IL-1RI were observed. Plasma membrane-bound IL-1RII decoy receptor was downregulated in OA chondrocytes. The levels of CAM aggrecan, type II collagen and fibronectin were significantly reduced in the chondrocytes obtained from pathological tissue.

CONCLUSION

Paired analysis of normal and OA chondrocytes from the same knee joint has shown an enhanced capacity of chondrocytes from OA cartilage to produce ECM macromolecules. However, the same cells have increased catabolic signalling pathways. As a consequence of this increased IL-1 activity and the reduced amounts of IL-1RII decoy receptor, less of the produced ECM macromolecules may persist in the CAM of the OA chondrocytes.

Systematic safety follow up in a cohort of 107 patients with spondyloarthropathy treated with infliximab: a new perspective on the role of host defence in the pathogenesis of the disease?

BACKGROUND

Recent studies with infliximab indicate the therapeutic potential of tumour necrosis factor alpha blockade in spondyloarthropathy (SpA). Because defective host defence is implicated in the pathogenesis of SpA, the potential side effects of this treatment due to impact on the antimicrobial defence are a major concern.

OBJECTIVE

To report systematically the adverse events seen in a large cohort of patients with SpA treated with infliximab, with special attention to bacterial infections.

PATIENTS AND METHODS

107 patients with SpA were treated with infliximab for a total of 191.5 patient years. All serious and/or treatment related adverse events were reported.

RESULTS

Eight severe infections occurred, including two reactivations of tuberculosis and three retropharyngeal abscesses, and six minor infections with clear bacterial focus. One patient developed a spinocellular carcinoma of the skin. No cases of demyelinating disease or lupus-like syndrome were seen. Two patients had an infusion reaction, which, however, did not relapse during the next infusion. Finally, three patients with ankylosing spondylitis developed palmoplantar pustulosis. All patients recovered completely with adequate treatment, and infliximab treatment had to be stopped in only five patients with severe infections.

CONCLUSIONS

Although the global safety of infliximab in SpA is good compared with previous reports in rheumatoid arthritis and Crohn's disease, the occurrence of infections such as tuberculosis and retropharyngeal abscesses highlights the importance of careful screening and follow up. Focal nasopharyngeal infections and infection related symptoms, possibly induced by streptococci, occurred frequently, suggesting an impairment of specific host defence mechanisms in SpA.

Anti-saccharomyces cerevisiae IgA antibodies are raised in ankylosing spondylitis and undifferentiated spondyloarthropathy

OBJECTIVES

To investigate whether anti-Saccharomyces cerevisiae antibodies (ASCA), a marker for Crohn's disease (CD), are present in spondyloarthropathies (SpA) and in the subgroups ankylosing spondylitis (AS), undifferentiated SpA (uSpA), and psoriatic arthritis (PsA), in comparison with healthy and inflammatory controls (patients with rheumatoid arthritis (RA)).

METHODS

ASCA IgA and IgG levels were measured with an enzyme linked immunosorbent assay (ELISA) kit (Medipan, Germany) in 26 patients with CD, 108 patients with SpA (43 patients with AS, 20 patients with uSpA, 45 patients with PsA), 56 patients with RA and 45 healthy controls. Gut biopsy samples were available in 18 AS and 10 patients with uSpA, these samples were screened for the presence of inflammation.

RESULTS

Both ASCA IgG and IgA levels were raised in CD compared with healthy controls and patients with RA. ASCA IgA, but not IgG levels, were higher in SpA than in both healthy and RA controls. ASCA IgA levels were raised in AS and uSpA, but not in PsA. No significant differences in ASCA IgA levels were noted between patients with SpA with and without histological gut inflammation.

CONCLUSION

ASCA IgA levels are significantly higher in SpA, and more specifically in AS, than in healthy controls and patients with RA. This is the first serum marker associated with SpA. No correlation between the presence of subclinical bowel inflammation and ASCA IgA levels was noted. However, it remains to be evaluated whether patients with SpA with ASCA have an increased risk of developing CD.

Increase in lymphoid follicles and leukocyte adhesion molecules emphasizes a role for the gut in spondyloarthropathy pathogenesis

The aim of this study was to investigate the expression of leukocyte adhesion molecules and the number of lymphoid follicles in gut mucosa of patients with spondyloarthropathy (SpA) in comparison with controls, in search for early immune alterations in the development of SpA-related gut inflammation. Histological evaluation and immunohistochemistry were performed on the ileum and colon of 14 SpA patients without macroscopic or microscopic gut inflammation and those of 21 controls. Lymphoid follicles were counted and immunohistochemical staining for leukocyte adhesion molecules, lymphocyte subtypes, macrophages, and plasma cells was scored semi-quantitatively. The number of lymphoid follicles was increased in both the ileum (p < 0.01) and the colon (p < 0.01) of SpA patients. SpA ileum showed an increase in leukocytes expressing CD11c (p < 0.01), whereas CD11a(+) (p < 0.02) and VCAM-1(+) cells (p < 0.05) were increased in SpA colon. Macrophages, characterized by the expression of CD68, were more numerous in colonic mucosa from SpA patients (p < 0.05). The amount of lymphoid follicles and lamina propria mononuclear cells expressing CD11a, CD11c, and VCAM-1 was increased in non-inflamed gut mucosa from SpA patients. These findings might point to increased antigen handling and presentation and augmented maturation of naïve T cells towards memory T cells in the SpA gut, which supports the concept that the gut is involved in the pathogenesis of SpA.

Diagnostic associations in a large and consecutively identified population positive for anti-SSA and/or anti-SSB: the range of associated diseases differs according to the detailed serotype

OBJECTIVE

To determine the diagnostic distribution in a consecutive anti-SSA and/or anti-SSB positive population.

METHODS

A total of 15 937 serum samples from 10 550 consecutive patients were analysed for antinuclear antibodies (ANAs) on HEp-2 cells. Serum samples positive for ANAs were analysed by immunodiffusion and line immunoassay with recombinant SSA-Ro52, natural SSA-Ro60, and recombinant SSB.

RESULTS

Among ANA positive patients in whom clinical information was available, 181 consecutive patients with anti-SSA and/or anti-SSB antibodies were identified, Disease associations were systemic lupus erythematosus (SLE) (45.3%), primary Sjögren's syndrome (pSS) (14.4%), scleroderma (8.8%), RA (7.7%), cutaneous lupus (7.7%), and dermatomyositis (2.2%). The ratio of diagnoses differed according to the anti-SSA/anti-SSB serotype. Scleroderma and dermatomyositis were enriched among mono-Ro52 reactive serum samples (34.2% and 10.5% respectively). Single reactivity towards Ro60 or anti-Ro60 with anti-Ro52 predisposed for SLE (80.0% and 52.2% respectively). Triple reactivity towards Ro52, Ro60, and SSB was primarily linked with SLE (55.8%) followed by pSS (20.9%). Anti-SSA on immunodiffusion increased the chance for SLE (62.8%), whereas isolated anti-SSB reactivity on immunodiffusion was less indicative for SLE (14.3%) and predisposed more for cutaneous lupus (23.8%) and pSS (33.3%).

CONCLUSION

The diagnostic range associated with anti-SSA or anti-SSB reactivity differs significantly according to the detailed serotype defined by line immunoassay and immunodiffusion.

Influence of the gut and cytokine patterns in spondyloarthropathy

Clinical and histological studies have previously shown that spondyloarthropathy (SpA) patients can have subclinical gut inflammation. This gut inflammation is related to enterocolitis in Crohn's disease (CD) and may evolve to overt inflammatory bowel disease in a subset of these patients. Moreover, there is an intriguing clinical link between gut inflammation and peripheral joint inflammation. In order to explore immunologically these concepts, recent studies have characterized phenotypically and functionally the inflammatory cells in both the gut and the synovium of SpA patients and have provided a number of new insights. Firstly, they confirm histological and pre-histological alterations of the gut immune system in SpA, which are redundant of CD and which are linked to alterations of the peripheral joints. Secondly, both the acquired and the innate immune system contribute to these alterations, with an important role for both T cells and macrophages and their cytokines. Thirdly, interpretation of these data support the hypothesis that gut and joint inflammation in SpA are induced by the combination of an impaired anti-bacterial host defence and an uncontrolled pro-inflammatory response of the innate immune system. The insights provided by the study of the gut immunology in SpA have contributed to develop new therapeutic strategies, with TNFalpha blockade as prototype.

Anti-Ro52 reactivity is an independent and additional serum marker in connective tissue disease

OBJECTIVE

To determine whether anti-Ro52 is an independent serum marker in connective tissue disease.

METHODS

Over a two year period, 1727 consecutive antinuclear antibody (ANA) positive serum samples were analysed in parallel by double immunodiffusion with thymus/spleen nuclear extract and by line immunoassay with recombinant Ro52, recombinant La/SSB, and natural Ro60. Sera that were only reactive towards Ro52 were further analysed by a variety of additional anti-SSA/Ro detection methods and by specific anti-Ro52 and anti-Ro60 assays. Natural purified SSA/Ro was analysed by immunoblot and protein sequencing.

RESULTS

Analysis of natural purified SSA/Ro (Immunovision, Springdale, AR) showed only Ro60 and no immunoreactive Ro52. Consequently, assays based on this substrate only identify sera with anti-Ro60 reactivity. Twenty serum samples showed anti-Ro52 without anti-Ro60 and anti-SSB/La on line immunoassay. By additional testing, 2/20 sera were found positive for anti-Ro60 reactivity. The remaining 18 sera were not identified by any of the classical anti-SSA/Ro assays and were considered to be reactive only with Ro52 and not with Ro60. This anti-Ro52 reactivity was confirmed by natural and recombinant Ro52 in 16/18 cases. 12/18 sera corresponded to connective tissue diseases.

CONCLUSION

Anti-Ro52 positive sera without any evidence of anti-Ro60 and anti-La/SSB reactivity can be considered as an independent group that is systematically missed by classical anti-SSA/Ro detection methods owing to a bias towards anti-Ro60 reactivity. The anti-Ro52 sera are precipitin negative, not retrieved by SSA/Ro enzyme linked immunosorbent assays (ELISAs) based on natural SSA/Ro, and show no specific ANA fluorescence staining pattern. These findings together with the clinical data indicate that anti-Ro52 should be considered as an additional and independent serum marker.

Influence of polysulphated polysaccharides and hydrocortisone on the extracellular matrix metabolism of human articular chondrocytes in vitro

OBJECTIVE

To evaluate the influence of hydrocortisone and two polysulphated polysaccharides (xylosan polysulphate and chondroitin polysulphate) on the extracellular matrix metabolism of chondrocytes cultured in gelled agarose.

METHODS

Isolated chondrocytes from normal femoral cartilage of the knee joints of 7 donors were cultured in gelled agarose to maintain their differentiated phenotype. After two weeks of culture, hydrocortisone (0.2 microgram/ml), xylosan polysulphate (10 micrograms/ml) and chondroitin polysulphate (10 micrograms/ml) were added to the culture media supplemented with or without interleukin (IL)-1 beta. After one week of incubation, the cells were liberated from the agarose with agarase. Isolated cells were labelled with antibodies against aggrecan and type II collagen, as well as biotinylated hyaluronic acid binding protein to analyse the extracellular matrix (ECM) molecules in the cell-associated matrix (CAM). The levels of matrix metalloproteinase (MMP)-1, -3, and -13, as well as tissue inhibitor of metalloproteinase (TIMP)-1 and -3 were determined after the cells had been permeabilised and stained with the appropriate antibodies. Triplicate samples were analysed with flow cytometry.

RESULTS

IL-1 beta decreased the accumulation of aggrecan, hyaluronan and type II collagen in the CAM and increased intracellular MMP-1, -3 and -13 at a concentration of 100 pg/ml. Xylosan polysulphate and chrondroitin polysulphate restored the expression of these CAM molecules in these IL-1 beta-treated cultures. Hydrocortisone stimulated the accumulation of CAM aggrecan and hyaluronan whether or not under the exposure to IL-1 beta. Intracellular MMP-1, -3, -13 and TIMP-1 and -3 of IL-1 beta-treated cells was downregulated after treatment with hydrocortisone.

CONCLUSION

Both hydrocortisone and the two polysulphated polysaccharides could stimulate the accumulation of CAM macromolecules of IL-1 beta-treated chondrocytes. This effect probably resulted in part from the downregulation of MMPs. These agents showed cartilage structure modifying effects in vitro.

Systems to assess the progression of finger joint osteoarthritis and the effects of disease modifying osteoarthritis drugs

Our objective was to assess the progression of osteoarthritis (OA) using scoring systems based on the anatomical changes recorded in the finger joints on standard radiographs and to test how far these scoring systems could be used to evaluate the effects of candidate "disease modifying osteoarthritis drugs" (DMOAD). The appearance and growth of osteophytes, narrowing of the joint space and subchondral bone changes allowed the classic OA-associated anatomical lesions to be used to score the progression of finger joint OA. Progression of OA in the finger joints was also assessed by the their evolution through previously described and predictable anatomical phases on standard X-rays. These phases were characterised by complete loss of the joint space preceding or coinciding with the appearance of subchondral cysts eroding the entire subchondral plate, and have been described in "inflammatory" or "erosive" OA. The erosive episodes were followed by processes of remodelling. In order to interfere with the progression of osteoarthritis, two chondroitin sulphates with possible DMOAD effects were used in two series of patients with OA of the finger joints. The patients were included in two separate randomised, double-blind placebo-controlled trials: 46 of them received chondroitin polysulphate and 34 received chondroitin sulphate. Eighty-five patients were kept on placebo medication and were used as controls. All 165 patients were followed for 3 years. Posteroanterior X-rays of the metacarpophalangeal and interphalangeal (IP) finger joints were obtained at the start of this prospective study and at yearly intervals thereafter. Almost 80% of the distal IP and 50% of the proximal IP were affected at study entry. In approximately 40% of the patients the classic picture of OA of the IP joints was complicated by manifest erosive OA changes. The two systems to score the progression of OA (Anatomical Lesion and Anatomical Phase Progression Score System) showed definite progression within 3 years of follow-up, especially in the IP joints. When compared with the placebo controls, none of the chondroitin sulphates prevented OA from occurring in previously normal finger joints. However, when the classic OA-associated anatomical lesions were considered, OA was less progressive in both active treatment groups. Furthermore, fewer patients from both chondroitin sulphate- and chondroitin polysulphate-treated groups developed "erosive" osteoarthritis. In conclusion, conventional radiographs can be used to assess the morbidity and progression of hand OA. The systems used to score the progression of finger joint OA allowed the DMOAD effects of both chondroitin sulphates to be evaluated. The data recorded during these pilot studies should help investigators to design future long-term clinical experiments.

Repeated infusions of infliximab, a chimeric anti-TNFalpha monoclonal antibody, in patients with active spondyloarthropathy: one year follow up

BACKGROUND

In a pilot study, the anti-tumour necrosis factor alpha monoclonal antibody, infliximab, induced a rapid and significant improvement in global, peripheral, and axial disease manifestations of patients with active spondyloarthropathy.

OBJECTIVE

To determine whether repeated infusions of infliximab would effectively and safely maintain the observed effect.

METHODS

Safety and efficacy of a maintenance regimen (5 mg/kg infliximab every 14 weeks) was evaluated using the measurements reported in the pilot study. Of the 21 patients, 19 completed the one year follow up for efficacy; two patients changed to another dosing regimen after week 12 owing to partial lack of efficacy. However, they are still being followed up for safety analysis.

RESULTS

After each re-treatment a sustained significant decrease of all disease manifestations was observed. Before re-treatment, symptoms recurred in 3/19 (16%) at week 20, in 13/19 (68%) at week 34, and in 15/19 (79%) at week 48. No withdrawals due to adverse events occurred. Twelve minor infectious episodes were observed. Twelve patients (57%) developed antinuclear antibodies; in four of them (19%) anti-dsDNA antibodies were detected. However, no lupus-like symptoms occurred.

CONCLUSION

In this open study of infliximab in patients with active spondyloarthropathy, the significant improvement of all disease manifestations was maintained over a one year follow up period without major adverse events. Although recurrence of symptoms was noted in a rising number of patients before each re-treatment, no loss of efficacy was observed after re-treatment.