Antinuclear antibodies are associated with tumor necrosis factor receptor I gene polymorphism in patients with rheumatoid arthritis.

OBJECTIVES: Antinuclear antibodies (ANA) are a common feature of autoimmune diseases such as rheumatoid arthritis (RA). Herein, we investigate the relationship between ANA and polymorphism in the tumour necrosis factor receptor (TNFR) genes. METHODS: Serum titers of ANA at diagnosis were measured in 267 patients with RA and a single nucleotide polymorphism (SNP) in each of the TNFR-I (36A/G) and TNFR-II (676T/G) genes was genotyped by polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) analysis. Circulating levels of soluble TNFR (sTNFR) and TNF-α were also measured in some patients. RESULTS: Our initial analyses revealed the presence of ANA was associated with the TNFR-I 36A/G SNP, with a trend of increasing ANA frequency with G allele dosage (p=0.004). ANA status was also associated with lower sTNFR-I levels and a raised sTNFR-II/sTNFR-I ratio. The TNFR-II 676T/G SNP and circulating levels of sTNFR-II and TNF-α were not associated with ANA status. In an adjusted multivariate regression model the TNFR-I 36 GG genotype (OR 7.8, p=0.008) and levels of sTNFR-I (p=0.018) were independently associated with ANA status. CONCLUSIONS: Our findings suggest a possible link between the production of ANA and the TNF-α/TNFR-I signalling system, which may be related to the apoptosis-inducing ability of this cytokine.

Fibromyalgia in patients with rheumatoid arthritis: driven by depression or joint damage?

OBJECTIVES: Studies have shown an increased incidence of fibromyalgia (FMS) in RA patients. The aims of this study were to explore the effect of mood and disease damage on the prevalence of FMS. METHODS: RA patients underwent a standardised clinical assessment, including disease activity (DAS-28), disease damage (mechanical joint score, MJS), fibromyalgia tender point assessment and the Hospital Anxiety and Depression Scale (HADS) and Health Assessment Questionnaire (HAQ). Patients were classified with FMS using two criteria a) tender-swollen joint count was ≥7 or b) tender point score of ≥11/18. RESULTS: 44/285 (15%) patients were classified as having FMS using the joint count difference of ≥7, compared to 18/285 (6%) using the tender point score of >11. Using the joint count difference to classify patients as having FMS, those with FMS had higher HAQ scores than those without FMS (2.12 vs. 1.5, p<0.0001). Although the DAS-28 was higher in this group (5.4 vs. 3.82, p<0.0001), the MJS was similar (8 vs. 7, p=0.19), suggesting similar levels of joint damage. Those classified as having FMS were more likely to have HAD-D scores of >11 (25% vs. 6%, p=0.0001). CONCLUSIONS: Coexistent FMS was common in our cohort, although using the tender point count to define FMS classified fewer patients with FMS. Within this group those with FMS had higher levels of depression but similar scores for joint damage indicating that in this cohort FMS and poorer physical functioning is mediated by low mood rather than joint damage.

Seven genomic subtypes of chronic fatigue syndrome/myalgic encephalomyelitis: a detailed analysis of gene networks and clinical phenotypes.

AIM: Chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME) is a multisystem disease, the pathogenesis of which remains undetermined. The authors have recently reported a study of gene expression that identified differential expression of 88 human genes in patients with CFS/ME. Clustering of quantitative PCR (qPCR) data from patients with CFS/ME revealed seven distinct subtypes with distinct differences in Medical Outcomes Survey Short Form-36 scores, clinical phenotypes and severity. METHODS: In this study, for each CFS/ME subtype, those genes whose expression differed significantly from that of normal blood donors were identified, and then gene interactions, disease associations and molecular and cellular functions of those gene sets were determined. Genomic analysis was then related to clinical data for each CFS/ME subtype. RESULTS: Genomic analysis revealed some common (neurological, haematological, cancer) and some distinct (metabolic, endocrine, cardiovascular, immunological, inflammatory) disease associations among the subtypes. Subtypes 1, 2 and 7 were the most severe, and subtype 3 was the mildest. Clinical features of each subtype were as follows: subtype 1 (cognitive, musculoskeletal, sleep, anxiety/depression); subtype 2 (musculoskeletal, pain, anxiety/depression); subtype 3 (mild); subtype 4 (cognitive); subtype 5 (musculoskeletal, gastrointestinal); subtype 6 (postexertional); subtype 7 (pain, infectious, musculoskeletal, sleep, neurological, gastrointestinal, neurocognitive, anxiety/depression). CONCLUSION: It was particularly interesting that in the seven genomically derived subtypes there were distinct clinical syndromes, and that those which were most severe were also those with anxiety/depression, as would be expected in a disease with a biological basis.

Association of DRB1 shared epitope genotypes with early mortality in rheumatoid arthritis: results of eighteen years of followup from the early rheumatoid arthritis study.

OBJECTIVE: To determine whether the HLA-DRB1 shared epitope (SE) is associated with early mortality and specific causes of death in rheumatoid arthritis (RA). METHODS: HLA-DRB1 genotyping was carried out on blood samples from 767 patients recruited for the Early RA Study (ERAS), a multicenter, inception cohort study with followup over 18 years. Dates and causes of death (n = 186) were obtained from the Office of National Statistics. The association of HLA-DRB1 alleles with risk of mortality was assessed using Cox proportional hazards regression analyses. Multivariate stepwise models were used to assess the predictive value of HLA-DRB1 genotypes compared with other potential baseline risk factors. RESULTS: The SE was not significantly associated with overall mortality. However, the presence of 2 SE alleles was associated with risk of mortality from ischemic heart disease (hazard ratio [HR] 2.02 [95% confidence interval 1.04-3.94], P = 0.04), and malignancy (HR 2.18 [95% confidence interval 1.17-4.08], P = 0.01). Analysis of specific SE genotypes (corrected for age and sex) revealed that the HLA-DRB1*0101/*0401 and 0404/*0404 genotypes were the strongest predictors of mortality from ischemic heart disease (HR 5.11 and HR 7.55, respectively), and DRB1*0101/*0401 showed a possible interaction with smoking. Male sex, erythrocyte sedimentation rate, and Carstairs Deprivation Index were also predictive, but the Health Assessment Questionnaire score, rheumatoid factor, nodules, and swollen joint counts were not. Mortality due to malignancy was particularly associated with DRB1*0101 genotypes. CONCLUSION: The risk of mortality due to ischemic heart disease or cancer in RA is increased in patients carrying HLA-DRB1 genotypes with particular homozygous and compound heterozygous SE combinations.

Association between cigarette smoking and release of tumour necrosis factor alpha and its soluble receptors by peripheral blood mononuclear cells in patients with rheumatoid arthritis.

OBJECTIVE: To investigate the relationship between cigarette smoking and release of TNF-alpha and its soluble receptors (sTNFRI and sTNFRII) by peripheral blood mononuclear cells (PBMCs) from RA patients. METHODS: We studied 71 RA patients with established disease (mean duration 10.6 yr). Smoking history was established by questionnaire. T lymphocytes and monocytes were isolated from peripheral blood and incubated with or without stimulation (phytohaemagglutinin and lipopolysaccharide, respectively). Release of TNF-alpha and sTNFR into culture medium was measured by enzyme-linked immunosorbent assay. RESULTS: TNF-alpha release by stimulated T lymphocytes was significantly higher in patients with a history of smoking than in those who had never smoked (1416.0 vs 767.4 pg/ml, P = 0.04), and showed a relationship with smoking duration and intensity (P for trend < or =0.009). Monocyte TNF-alpha release was not associated with smoking status. Release of sTNFR showed no clear relationships with extent of smoking, although release by stimulated T lymphocytes was higher in past smokers than in those who had never smoked (P < or = 0.03). The ratio of TNF-alpha/sTNFR released from T lymphocytes was higher in past and current smokers, and was associated with extent of smoking. No relationship was found between smoking and plasma TNF-alpha levels, but levels of both receptors were higher in past smokers. CONCLUSION: In RA patients who smoke there is an alteration in the ratio of TNF-alpha/sTNFR released by stimulated T cells that might favour increased TNF-alpha activity. The increased TNF-alpha/sTNFR ratio is associated with extent of smoking, and remains elevated after smoking cessation.

Association of chronic fatigue syndrome with human leucocyte antigen class II alleles.

BACKGROUND: A genetic component to the development of chronic fatigue syndrome (CFS) has been proposed, and a possible association between human leucocyte antigen (HLA) class II antigens and chronic fatigue immune dysfunction has been shown in some, but not all, studies. AIMS: To investigate the role of HLA class II antigens in CFS. METHODS: Forty nine patients with CFS were genotyped for the HLA-DRB1, HLA-DQA1, and HLA-DQB1 alleles and the frequency of these alleles was compared with a control group comprising 102 normal individuals from the UK. All patients and controls were from the same region of England and, apart from two patients, were white. RESULTS: Analysis by 2 x 2 contingency tables revealed an increased frequency of HLA-DQA1*01 alleles in patients with CFS (51.0% v 35%; odds ratio (OR), 1.93; p = 0.008). HLA-DQB1*06 was also increased in the patients with CFS (30.2% v 20.0%; OR, 1.73, p = 0.052). Only the association between HLA-DQA1*01 and CFS was significant in logistic regression models containing HLA-DQA1*01 and HLA-DRQB1*06, and this was independent of HLA-DRB1 alleles. There was a decreased expression of HLA-DRB1*11 in CFS, although this association disappeared after correction for multiple comparisons. CONCLUSIONS: CFS may be associated with HLA-DQA1*01, although a role for other genes in linkage disequilibrium cannot be ruled out.

Cytokine gene polymorphisms associated with symptomatic parvovirus B19 infection.

BACKGROUND: The immune system has been implicated in the pathogenesis of certain clinical manifestations of parvovirus B19 infection, including rash and arthralgia. Cytokines feature in the pathogenesis of parvovirus B19 infection, so inherited variability in cytokine responses to B19 infection might have a bearing on the symptomatology of parvovirus B19 infection. AIMS: To investigate the possible role of cytokine gene polymorphisms in the clinical manifestations of parvovirus B19 infection. METHODS: Thirty six patients with a variety of symptoms at acute infection and follow up (mean, 22.0 months) and controls (99-330, depending on the locus) were examined for the following cytokine polymorphisms: tumour necrosis factor alpha (TNF alpha), -308; interferon gamma (IFN-gamma), +874; interleukin 6 (IL-6), -174; IL-10, -592, -819, and -1082; and transforming growth factor beta1 (TGF beta 1), +869 (codon 10) and +915 (codon 25). RESULTS: The TNF alpha -308*A allele occurred in 13.9% of the parvovirus group compared with 27.0% of the control group (odds ratio (OR), 0.44; p = 0.02). The TGF beta 1 CG/CG haplotype was more frequent in the parvovirus group than in the controls (16.7% v 5%; OR, 4.8; p = 0.02). Within the B19 infected group, the TGF beta 1 +869 T allele was associated with skin rash at acute infection (p = 0.005), whereas at follow up the IFN-gamma +874 T allele was associated with the development of anti-B19 non-structural protein 1 antibodies (p = 0.04). CONCLUSIONS: The results of the present study suggest that inherited variability in cytokine responses may affect the likelihood of developing symptoms during parvovirus infection.

Serum complexes of immunoglobulin A-alpha1 proteinase inhibitor in rheumatoid arthritis: association with current cigarette smoking and disease activity.

OBJECTIVE: To investigate whether high levels of serum immunoglobulin A-alpha1 proteinase inhibitor (IgA-alpha1PI) complexes are primarily associated with cigarette smoking or the rheumatoid arthritis (RA) disease process itself. METHODS: A case-control study consisting of 231 RA cases and 83 healthy hospital workers. A smoking history was taken for the study groups. The serum IgA-alpha1PI complex levels (arbitrary units, au) were determined using a sandwich ELISA. Erythrocyte sedimentation rate (ESR) and rheumatoidfactor (RF) measurements were recorded in each of the RA cases. The serum complex levels were compared between RA cases and controls matched for smoking history and between smokers and non-smokers in the RA cases and controls. RESULTS: Mean serum IgA-alpha1PI complex levels were significantly higher in RA current smokers than in non-smoking RA patients (17.4 v 11.9 a.u., p = 0.0001). Similarly, mean serum complex levels were significantly higher in control current smokers than control non-smokers (18.8 v 11.5 a.u., p = 0.003). Seropositive RA cases had significantly higher complex levels than seronegative cases. Patients with erosive disease had higher levels than non-erosive patients, although significance was lost after correction for current smoking and RF positivity. There was an association between ESR and serum IgA-alpha1PI complex levels which was independent of current smoking. Overall, there was no significant difference in complex levels between RA cases and controls after correction for current smoking. CONCLUSION: Raised serum IgA-alpha1PI complex levels are associated with current smoking in both RA and healthy controls. ESR levels in RA patients are also associated with serum complex levels independently of current smoking. Our data suggest that high IgA-alpha1PI complex levels can be generated either as a result of current smoking, or by an active disease process in RA patients.

IL-6 promoter polymorphism at position -174 modulates the phenotypic expression of polymyalgia rheumatica in biopsy-proven giant cell arteritis.

OBJECTIVES: Giant cell arteritis (GCA) and polymyalgia rheumatica (PMR) are related diseases in which diverse genetic and environmental factors are implicated. Both GCA and PMR are characterized by an intense acute phase reaction. In these sYndromes the increased production of IL-6 has been observed. To investigate further the genetic influence of IL-6 in GCA and PMR we have examined the IL-6 promoter polymorphism (G to C) at position -174 in the 5' region in a series of patients from Northwest Spain diagnosed with GCA and/or PMR. METHODS: Sixtxy-two biopsy-proven GCA patients (30 of them with associated PMR) and 84 patients with isolated PMR were studied. Patients and ethnically matched controls (n = 124) were from the Lugo region (Galicia, Northwest Spain). Patients and controls were genotyped for HLA-DRB1 and IL-6 polymorphism at position -174 by molecular methods. RESULTS: IL-6-174 allele C was marginally increased infrequency in GCA patients with PMR manifestations compared with isolated GCA (Pcorr 0.06; OR = 2.3). The increase in the frequency of the CC genotype in GCA patients with PMR versus those with isolated GCA was statistically significant (Pcorr 0.02). The increased frequency of allele C in GCA patients with PMR was more commonly observed in HLA-DRBI *04 negative patients. However, this polymorphism was not associated with a higher risk of ischemic events in GCA or with relapses in PMR. CONCLUSION: Allele C at position -174 in the 5' promoter region of the IL-6 gene may be associated with PMR in biopsy-proven GCA patients not carrying HLA-DRBI *04 alleles.

The mechanical joint score: a new clinical index of joint damage in rheumatoid arthritis.

OBJECTIVES: To evaluate the mechanical joint score (MJS) in terms of its reliability between observers and over time, its ease of use and its relationship with conventional measures of rheumatoid arthritis (RA) disease activity, severity and functional outcome. METHODS: The MJS was evaluated in 103 patients with reference to the following joints: total proximal interphalangeal (PIP) joints, total metacarpophalangeal (MCP) joints, wrists, elbows, shoulders, hips, knees, ankles and total metatarsophalangeal (MTP) joints. The score was based on the appearance of the joints on a scale of 0-3, 0 representing no abnormality and 3 severe abnormality or previous surgery. The MJS was evaluated in terms of its intra- and inter-observer variability and its content, construct and criterion validities. A subset of 29 patients were re-evaluated after 5 yr to examine change in MJS over time. RESULTS: The MJS performed well in terms of inter-observer and intra-observer reliability. The MJS showed strong correlation with the Larsen X-ray score of hands and feet (Spearman correlation coefficient 0.74) and with the modified Health Assessment Questionnaire (Spearman correlation coefficient 0.56) and only weak correlation with indices of disease activity, such as the Ritchie index and erythrocyte sedimentation rate. The MJS showed highly significant positive change over time. CONCLUSION: The MJS is a reliable clinical index of joint damage and may be a useful new outcome measure in RA.

Lack of association between intercellular adhesion molecule-1 gene polymorphisms and giant cell arteritis.

OBJECTIVE: Studies have shown an association between HLA-DRB1*04 and giant cell arteritis (GCA). Intercellular adhesion molecule-1 (ICAM-1) gene polymorphisms were reported to contribute susceptibility to GCA in Italian patients where susceptibility to GCA is not associated with HLA-DRB1*04 alleles. ICAM-1 is also highly expressed within inflammatory infiltrates of the blood vessels of GCA patients. To investigate the clinical implications of ICAM-1 polymorphisms in GCA, we examined their potential association and influence in the development of visual ischemic complications in a series of patients with GCA from Northwest Spain where GCA susceptibility is associated with HLA-DRB1*04. METHODS: Fifty-eight biopsy proven GCA and 129 ethnically matched controls were studied. Patients and controls were genotyped for ICAM-1 polymorphism at codons 241 and 469 by PCR-RFLP. RESULTS: The distribution of the alleles and genotypes for each ICAM- polymorphism did not show significant differences between GCA patients and controls. Although visual manifestations were significantly more likely to occur in men than women (OR 5.2, p = 0.018), allele and genotype frequencies of ICAM-1 polymorphisms in patients with GCA were not associated with development of visual complications or anemia. Visual complications in GCA were primarily associated with carriage of an HLA-DRB1*04 allele. No evidence was found for interaction between HLA-DRB1*04 and ICAM-1 polymorphism. CONCLUSION: ICAM-1 polymorphisms are not genetic risk factors for the susceptibility and severity of GCA in Northwest Spain.

Raised levels of F(2)-isoprostanes and prostaglandin F(2alpha) in different rheumatic diseases.

OBJECTIVE: To evaluate oxidative injury and inflammatory status in various rheumatic diseases by measuring the levels of isoprostanes and prostaglandins in serum and synovial fluid. METHODS: The concentrations of 8-iso-PGF(2alpha) (F(2)-isoprostane indicating oxidative injury) and 15-keto-dihydro-PGF(2alpha) (a major metabolite of prostaglandin F(2alpha)) were measured in both serum and synovial fluid aspirated from 26 patients with various arthritic diseases, including rheumatoid arthritis (RA), reactive arthritis (ReA), psoriatic arthritis (PsA), and osteoarthritis (OA). These prostaglandin derivatives were also measured in serum samples collected from 42 healthy control subjects. RESULTS: Overall, serum levels of 8-iso-PGF(2alpha) and 15-keto-dihydro-PGF(2alpha) were much higher in patients with arthritic diseases than in the healthy control subjects. The levels of 8-iso-PGF(2alpha) and 15-keto-dihydro-PGF(2alpha) in synovial fluid aspirated from knee joints were also high and varied among various types of arthritic patients. Although the synovial fluid level of these prostaglandin derivatives was sometimes higher than in the corresponding serum sample, this was not a consistent finding. Overall, there was no correlation between serum and synovial fluid levels of 8-iso-PGF(2alpha), or between serum and synovial fluid levels of 15-keto-dihydro-PGF(2alpha). However, a strong relation was found between the levels of 8-iso-PGF(2alpha) and 15-keto-dihydro-PGF(2alpha,) in both serum (r(s)=0.53, p<0.001) and synovial fluid (r(s)=0.62, p<0.001). CONCLUSIONS: These data suggest that both free radical mediated oxidative injury and cyclo-oxygenase dependent inflammatory responses are closely correlated in various types of arthritis.

Influence of HLA-DRB1 and TNF microsatellite polymorphisms on the expression of extraarticular manifestations in rheumatoid arthritis patients from northwest Spain.

OBJECTIVE: To determine whether extraarticular manifestations (EAM) in rheumatoid arthritis (RA) patients from northwest (NW) Spain are associated with particular HLA-DRB1 alleles and/or TNF microsatellite polymorphisms. METHODS: The frequencies of HLA-DRB1 alleles and TNF microsatellite polymorphisms were compared between RA patients with and without extraarticular disease in a population from Lugo, NW Spain. HLA-DRB1 and TNF typing were carried out using molecular based methods on 181 clinic-based RA patients and 145 healthy controls. Associations were investigated using Chi-square analyses or Fisher's exact test. Multivariate logistic regression analyses were used to investigate independent and interactive effects of HLA and TNF alleles. RESULTS: The frequencies of HLA-DRB1 and TNF microsatellite polymorphisms in patients with EAM were not significantly different from those without extraarticular disease, although an association between HLA-DRB1*0101 and nodular disease approached significance (p = 0.054). There was no evidence for an increased frequency of homozygous or heterozygous combinations of disease associated DRB1 alleles in RA patients with EAM. The TNF a8 microsatellite allele was found at a higher frequency (6.9%) in patients with EAM compared to those without EAM (1.8%), and controls (1.5%) (p = 0.03 and 0.02, respectively). However significance was lost after correction for multiple testing. No evidence was foundfor an interaction between HLA-DRB1 and TNF alleles being associated with the expression of EAM. CONCLUSION: In an RA population from NW Spain the frequencies of HLA-DRB1 and TNF microsatellite alleles in patients with extra-articular manifestations were not significantly different to those without extraarticular disease, although there was a trend towards increased frequency of HLA-DRB1*0101 in patients with nodular disease. There was no evidence for an interaction between HLA-DRB1 and TNF alleles in relation to the expression of EAM.

Association of giant cell arteritis and polymyalgia rheumatica with different tumor necrosis factor microsatellite polymorphisms.

OBJECTIVE: To determine whether giant cell arteritis (GCA) and polymyalgia rheumatica (PMR) are associated with different tumor necrosis factor (TNF) microsatellite polymorphisms. METHODS: Typing of TNF microsatellite polymorphisms was carried out by molecular-based techniques on DNA obtained from a population sample of residents from Lugo, northwestern Spain. A case-control approach was used to compare 136 patients with GCA and/or PMR with 147 ethnically matched controls. The association of disease with TNF microsatellite polymorphisms was investigated using chi-square tests and multivariate logistic regression analyses. RESULTS: Different TNF microsatellite associations were found with GCA and PMR. In patients with isolated GCA, the primary association was with TNFa2, which was independent of the GCA associations with HLA-DRB1*0401 and *0101. A negative association was found with TNFa10. In patients with isolated PMR, there was a positive association with TNFb3. This was found to be independent of the HLA-DRB1*13/*14 association in isolated PMR. TNFd4 was negatively associated with isolated PMR. Forward stepwise logistic regression analyses indicated that the strongest association with GCA was provided by the TNFa2 allele, although DRB1*0401 and *0101 were still associated. PMR was primarily associated with TNFb3. A direct comparison of TNF allele frequencies between isolated GCA and isolated PMR indicated that the main difference between these conditions occurred in the frequency of TNFa10. CONCLUSION: GCA and PMR in individuals from northwestern Spain are associated with different TNF microsatellite polymorphisms. The primary TNF associations (TNFa2 and TNFb3) appear to influence susceptibility to these conditions independent of any HLA-DRB1 association.

Different gene loci within the HLA-DR and TNF regions are independently associated with susceptibility and severity in Spanish rheumatoid arthritis patients.

The aim of this study was to investigate whether polymorphisms in the tumor necrosis factor (TNF) and HLA-DRB1 gene regions are independently associated with rheumatoid arthritis (RA) in a population from Lugo region of northwestern Spain. RA patients (n=179) attending hospital outpatient clinics in Lugo, northwestern Spain and matched controls (n=145) were recruited. RA susceptibility in this population was predominantly associated with DRB1*0401, while erosive disease was associated with HLA-DRB1*0101 and DRB1*04. The increase in DRB1*04 was accounted for by an increase in DRB1*0404 and *0405 but not *0401 frequencies. In contrast, *0401 frequency was significantly increased in seropositive patients. The rheumatoid arthritis shared epitope (SE) was associated with increased risk for seropositive and erosive disease and this appeared to operate in a dose-dependent manner. Logistic regression analyses revealed that the TNF microsatellite markers TNFc1 and b3 were associated with RA independently of DRB1*04 and the SE. Carriage of a TNF c1 allele provided an increased risk of RA in SE-negative and SE-heterozygous individuals. TNFc1 and TNFb3 were not associated with erosive or seropositive disease. In contrast, TNF a2 was significantly associated with erosive disease which was independent of DRB1*04 and the SE. Further studies will be needed to establish why (TNFc1) polymorphism seemingly associated with low TNFalpha production, is a risk factor for RA.

Antibodies to neuroblastoma cells in rheumatoid arthritis: a potential marker for neuropathy.

OBJECTIVE: To investigate the prevalence of antibodies to neuroblastoma cells in patients with rheumatoid arthritis (RA) complicated by peripheral neuropathy (PN), and to determine whether there is any relationship of these antibodies with the severity of neuropathy. METHODS: The study was carried out on 28 patients with RA complicated by PN, 29 RA patients without PN and 28 healthy volunteers (HV). A cell-based ELISA method was used to test sera for the presence of IgG and IgM anti-neuroblastoma cell antibodies. Localisation and characterisation of neuroblastoma antigens recognised by patients' sera was carried out by immunofluorescent microscopy and Western blotting. RESULTS: Elevated levels of IgG anti-neuroblastoma cell antibodies were found in 10 (36%) neuropathic patients and in 1 (3%) RA control (chi 2 = 9.53, P = 0.002), while significant levels of IgM anti-neuroblastoma cell antibodies were demonstrated in 10 (36%) neuropathic patients and in 2 (7%) RA controls (chi 2 = 7.12, P = 0.008). Overall, the levels of antibodies in healthy volunteers were significantly lower than in RA controls and patients with PN. No significant relationship was found between the level of anti-neuroblastoma cell antibodies and severity of RA or neuropathy. Immunofluorescence staining of neuroblastoma cells with sera from 18 neuropathic patients demonstrated cytoplasmic and/or nuclear patterns. Western blotting demonstrated reactivity with a heterogeneous group of neuroblastoma antigens. Little or no reactivity was seen with RA control or HV sera. CONCLUSION: Antibodies against neuroblastoma cells are more prevalent in RA patients with peripheral neuropathy than in RA patients without peripheral nerve involvement. Such antibodies may be useful diagnostic markers for peripheral neuropathy in RA.

Oxidation of alpha1-proteinase inhibitor by the myeloperoxidase-hydrogen peroxidase system promotes binding to immunoglobulin A.

We have demonstrated previously that patients with rheumatoid arthritis (RA) show an increase in serum and synovial fluid levels of complexes between alpha1-proteinase inhibitor (alpha1PI) and IgA. These are believed to form through disulfide binding between the Cys232 residue on alpha1PI and the penultimate cysteine residue (Cys471) of the IgA alpha chain. The mechanism for this has not been elucidated. We show here that alpha1PI oxidized by the myeloperoxidase-hydrogen peroxide (MPO-H2O2) system promotes the formation of IgA-alpha1PI complexes when incubated with IgA and that such complexes have no inhibitory activity against porcine pancreatic elastase (PPE). The activity of alpha1PI was considerably reduced also in IgA-alpha1PI complexes isolated from serum of an RA patient. We suggest that formation of IgA-alpha1PI complexes in inflammation may involve oxidation of alpha1PI, and as a consequence the alpha1PI in such complexes has reduced elastase inhibitory activity.

Interaction between tumor necrosis factor microsatellite polymorphisms and the HLA-DRB1 shared epitope in rheumatoid arthritis: influence on disease outcome.

OBJECTIVE: To investigate whether interactions between tumor necrosis factor (TNF) microsatellite polymorphisms and the HLA-DRB1 shared epitope (SE) are associated with disease severity in rheumatoid arthritis (RA), and to determine if such associations are the same in male and female patients. METHODS: Genotyping for the TNFa microsatellite and HLA-DRB1 was carried out on 157 RA patients with established disease (duration >5 years). Disease severity measures included radiographic damage (the Larsen method), functional assessment by the Health Assessment Questionnaire, history of joint surgery, and global appraisal of outcome by means of a visual analog scale score. The association of severity measures with TNFa microsatellite polymorphisms stratified by SE status, and the interaction between TNFa and the SE, were investigated using stratified analyses and multiple or logistic regression analyses. RESULTS: No significant associations were observed between any single TNFa microsatellite polymorphism and disease severity, although preliminary evidence for an interaction between TNFa6 and TNFa11 was obtained. In the presence of the SE, a significantly worse outcome was associated with individuals carrying TNFa6, and a significant interaction (P = 0.04-0.006) was found between these alleles for all the outcome measures examined except history of joint surgery. In the absence of the SE, the TNFa6 allele was associated with significantly better outcome scores. When examined by sex, significant associations between the TNFa6/SE haplotype and disease outcome measures were found only in females. No statistically significant interactions were found in males, although the TNFa6/SE haplotype was still associated with the worst outcome scores. CONCLUSION: The association of the SE with disease severity in RA is influenced by an interaction with the TNFa6 microsatellite polymorphism. This interaction appears to be acting predominantly in female patients, although the trend is similar in the smaller percentage of males carrying the TNFa6/SE haplotype.

Prevalence of antibodies to neurofilament polypeptides in patients with rheumatoid arthritis complicated by peripheral neuropathy.

OBJECTIVE: Neurofilaments are essential components of the axon cytoskeleton. Neurofilament defects are suspected in several neurodegenerative conditions, and antibodies to neurofilaments have been found in autoimmune diseases such as rheumatoid arthritis and systemic lupus erythematosus. Our main objectives were: (i) to determine the prevalence of anti-neurofilaments antibodies in patients with rheumatoid arthritis (RA) complicated by peripheral neuropathy; and (ii) to relate the clinical features of RA and peripheral neuropathy to anti-neurofilament antibodies. METHODS: In this study we used an ELISA technique to measure IgG antibody levels against three neurofilament polypeptides (NF-L, 70 kD; NF-M, 150 kD; and NF-H, 200 kD) in RA patients with peripheral neuropathy, and compared them with the antibody levels in uncomplicated RA controls and healthy volunteers. RESULTS: Abnormal antibody levels to one or more of the neurofilament polypeptides were found in 9 (32%) of the peripheral neuropathy patients, but only in 3 (9%) of the RA and healthy controls. There were significant correlations between the levels of antibodies against the different neurofilaments; the cross-reactivity of some sera with different neurofilament proteins was also observed. There was no significant correlation between the levels of anti-neurofilament antibodies and measures of RA disease activity. CONCLUSIONS: We conclude that a significant proportion of our RA patients with neuropathy had abnormal antibody levels to one or more neurofilaments and that the measurement of these antibodies may provide a useful diagnostic test.

Transforming growth factor beta 1 and interleukin 4 induced alpha smooth muscle actin expression and myofibroblast-like differentiation in human synovial fibroblasts in vitro: modulation by basic fibroblast growth factor.

OBJECTIVE: To discover if alpha smooth muscle actin expression and myofibroblastic differentiation are induced in synovial fibroblasts by cytokines found in the inflamed RA joint. METHODS: Immunofluorescent microscopy and western blotting were used to examine different cultures of human synovial fibroblasts for expression of alpha actin in the presence of the cytokines transforming growth factor beta (TGF beta 1), interleukin 1 alpha (IL1 alpha), IL4, IL6, tumour necrosis factor alpha (TNF alpha), and basic fibroblast growth factor (FGF). RESULTS: A small but significant population of cells (14.4 +/- 12.9%) expressed alpha actin under standard culture conditions. Upon treatment with TGF beta 1 there was a pronounced increase in the number of cells expressing alpha actin (68.1 +/- 5.49%), accompanied by a change in morphology to a myofibroblast-like phenotype. Other cytokines found within the inflamed joint such as IL1, TNF alpha, IL6, and basic FGF failed to induce alpha actin expression. However, IL4, which is normally absent or only present at low concentrations in the RA joint had a similar effect to TGF beta 1. It was also found that basic FGF inhibited the induction of alpha actin expression by TGF beta 1 and IL4. CONCLUSION: In the presence of TGF beta 1 or IL4, fibroblasts derived from synovial tissue or synovial fluid are induced to differentiate into myofibroblast-like cells containing the alpha smooth muscle form of actin. This differentiation is inhibited by basic FGF. It is suggested that the balance between these particular cytokines may be important in the modulation of fibroblast behaviour, which could have significant effects on joint repair mechanisms and the generation of fibrous tissue within the rheumatoid joint.