Epicardial fat thickness in patients with rheumatoid arthritis

Background

Epidemiologic data indicates that rheumatoid arthritis is an independent risk factor for cardiovascular disease. Epicardial adipose tissue is a novel cardio-metabolic risk factor. Our aim was to evaluate epicardial fat thickness (EFT) using echocardiography in patients with rheumatoid arthritis compared to healthy control subjects. Secondly, we investigated relationship between epicardial fat thickness and clinical and echocardiographic parameters in patients with rheumatoid arthritis.

Method

The study population included 76 consecutive patients with rheumatoid arthritis (64 female; mean age, 53 ±11 years, median disease duration, 7.8 years) and 50 healthy subjects as controls (39 female; mean age, 52 ± 6 years). All patients underwent echocardiography to assess left ventricular diastolic dysfunction, left ventricular hypertrophy and EFT. All values were compared between groups.

Results

EFT was higher in rheumatoid arthritis patients than in healthy controls (0.66±0.20 vs. 0.54±0.18; p= 0.003). Thickness of Intra Ventricular Septum (IVS) (1.1±0.06 and 9.8±0.08; p=0.001) and posterior wall (PW) (0.98±0.05 and 0.93±0.08; p=0.015) was higher in patients with rheumatoid arthritis compared to healthy controls. Early diastolic myocardiac peak velocity or late diastolic mitral peak velocity (E/A) ratio was lower in rheumatoid arthritis patients compared to healthy patients (1.1 ±0.8 and 1.24±0.1 p=0.001) as well as, E/e'' was higher in Rheumatoid arthritis (RA) patients than healthy patients. (E/e'':8.7±1.6 and 8.0±1.4 p=0.020). In patients with rheumatoid arthritis, EFT was positively correlated with hypertension and duration of disease and E/e'' (r: 0.10, p: 0.010, r: 0.306, p: 0.004 and r: 0.465 p: 0.007 respectively) and EFT was negatively correlated with E/A (r: −.262 p:0.022)

Conclusion

To our knowledge, this is the first report about epicardial adipose tissue in rheumatoid arthritis patients. Epicardial fat thickness as an indicator of cardiovascular involvement was higher in rheumatoid arthritis patients.     

Autoantibodies in lepromatous leprosy

Lepromatous leprosy patients often develop erythema nodusum leprosum (ENL) reactions mainly during treatment of the disease. Hence, this study sought to investigate correlation between the prevalence of certain autoantibodies and ENL reactions in these patients. The patients included in the study were fifty patients with lepromatous leprosy and a similar number of normal controls. Sera were collected from the patients and normal controls and the prevalence of circulating rheumatoid factor antinuclear and antismooth muscle antibodies was determined. The prevalence of autoantibodies was increased in lepromatous leprosy as compared with normal controls. The prevalence of these autoantibodies were affected differently by the ENL reactions. ENL lepromatous leprosy showed a slight decrease in prevalence of antinuclear and antismooth muscle antibodies, whereas there was a slight increase in the prevalence of rheumatoid factor in ENL lepromatous leprosy. The levels of serum immunoglobulins tended to show a decline towards ENL lepromatous patients compared with the uncomplicated lepromatous patients. The significance of these finding is discussed in relation to their possible role in the pathogenesis of ENL reaction. It is concluded that some of these autoantibodies and immunoglobulins may be utilized during ENL reactions in the formation of immune complexes.     

Novel autoantibody markers for early and seronegative rheumatoid arthritis

Approximately one-third of rheumatoid arthritis (RA) patients are seronegative for the 2 serological RA markers, rheumatoid factor (RF) and antibodies against cyclic citrullinated peptides (ACCP). Moreover, the sensitivities of both markers are lower in the diagnostically important early disease phase. The aim of this study was to identify additional autoantibody markers for early RA and for RF-negative, ACCP-negative (seronegative) RA.We screened an RA synovium cDNA phage display library with autoantibodies in plasma from 10 early (symptoms of maximum 1 year) and 10 seronegative (RF-negative, ACCP-negative) RA patients with validation in 72 additional RA patients and 121 controls (38 healthy controls, 43 patients with other inflammatory rheumatic diseases, 20 osteoarthritis patients and 20 subjects with mechanical joint complaints). Fourteen novel autoantibodies were identified that showed a 54% sensitivity and 90% specificity for RA. For 11 of these autoantibodies, an exclusive presence was demonstrated in RA patients (100% specificity, 37% sensitivity) as compared to controls. All early RA patients were positive for at least one of the identified autoantibodies and antibody-positivity was associated with a shorter disease duration (P = 0.0087). 52% of RA patients who initially tested negative for RF and ACCP, tested positive for at least one of the 14 novel autoantibodies, resulting in a 19% increase in sensitivity compared to current serological testing. Moreover, 5 identified autoantibodies were detected more frequently in seronegative RA patients, indicating that these autoantibodies constitute novel candidate markers for this RA subtype. We demonstrated that the targets of 3 of these 5 autoantibodies had an increased expression in RA synovial tissue compared to control synovial tissue, pointing towards a biological rationale for these auto antibody targets in RA.In conclusion, we identified novel candidate autoantibody markers for RA that can be detected in early and seronegative RA patients indicating the potential added value for RA diagnostics.     

Autoantibodies against Tmu and B lymphocytes in patients with rheumatoid arthritis.

Patients with rheumatoid arthritis have decreased numbers of T mu lymphocytes in their peripheral blood. To find out whether these low number of T mu lymphocytes were associated with the presence of anti-lymphocyte antibodies, the sera of 27 patients with definite or classical rheumatoid arthritis (RA) were investigated for the presence of autoantibodies against subsets of lymphocytes. In addition the numbers of T, T mu, T gamma and B lymphocytes in the peripheral blood of these patients were investigated. Patients with active RA showed lower numbers of T mu lymphocytes in their peripheral blood than patients with inactive RA. However, both groups of RA patients had significantly decreased numbers of T mu lymphocytes in their peripheral blood as compared with 22 age matched healthy donors. Moreover, mainly in patients with active RA cold reactive antibodies were found directed against T mu and B lymphocytes, but never against T gamma lymphocytes of healthy donors. Similar results were found in the indirect immunofluorescence procedure when tested for reactivity against T-cell subsets. This serum reactivity was not caused by rheumatoid factors or antinuclear antibodies. Since RA sera after precipitation with 2.5% polyethyleneglycol, still showed cytotoxicity against T and B lymphocytes, it is suggested that this serum reactivity is not caused by immune complexes but by antibodies.     

Defective serum chemotactic capacity in rheumatoid arthritis

Polymorphonuclear leukocytes (PMN) chemotaxis and serum chemoattractant ability were studied in patients with rheumatoid arthritis (RA) employing the agarose plate technique. No statistically significant differences were observed in random migration of unstimulated cells compared to the controls. Moreover, there were no statistically significant differences between the chemotactic migration of control and patient cells in response to a number of non-treated sera. The chemotactic responsiveness of normal PMN cells to treated rheumatoid serum was significantly less than that observed using treated control serum with Escherichia coli lipopolysaccharide. The possible explanation for this abnormality may be due to the presence of chemotactic inhibitors in some RA serum. No correlation was detected between chemoattractant activity of rheumatoid arthritis serum, circulating immune complexes or rheumatoid factor. There were no statistically significant differences in the adhesiveness of RA-PMNs compared to normal PMNs.     

Immunopathological changes in rheumatoid arthritis and other joint diseases.

A comparative study of the distribution of immunoglobulins G, M, and A and C3 in the synovium and inside synovial fluid leucocytes and of the relative levels of IgG, IgM, AND C3 in paired samples of serum and synovial fluid from both seropositive and seronegative patients with rheumatoid arthritis and other types of non-infective synovitis shows that although there is no distinctive immunopathological feature of rheumatoid arthritis, the incidence of immune complexes containing IgG and IgM with and without detectable C3 in the affected synovium or inside synovial fluid granulocytes is higher in rheumatoid arthritis and especially so in seropositive cases. The mean level of C3 in synovial fluid from patients with rheumatoid arthritis is lower than that from the group without rheumatoid arthritis. In contrast to previous reports, extracellular clumps of IgA could be detected in the affected synovium of a number of affected patients. Aggretated human IgG could be bound by some of the synovial biopsies and synovial fluid leucocytes from both seropositive and seronegative rheumatoid arthritis patients. Antinuclear factor and rheumatoid factor could be detected in the synovial fluid but not in the serum of several patients suggesting either selective sequestration or local synthesis of antinuclear and rheumatoid factors in the affected joints.     

Atopy and rheumatoid arthritis

The prevalence of rheumatoid arthritis (RA) was studied among 266 atopic patients attending an allergy clinic. Two patients had definite RA, a prevalence similar to that seen in the general population. We also studied the prevalence of atopy (positive skin-prick tests) and diseases associated with atopy among forty patients with RA and forty age- and sex-matched controls. The two groups had a similar prevalence of atopy (5 RA patients, nine controls) and atopic diseases (fourteen RA patients, fourteen controls) and they did not differ with respect to blood eosinophil counts or total serum IgE. Positive RAST tests to inhaled allergens were found in three RA patients and five controls and all patients had negative RAST tests to milk and egg. It was concluded that patients with rheumatoid arthritis have a normal prevalence of atopy and atopic diseases and we found no evidence that allergic factors contributed to the arthritis of the forty RA patients in the study.     

Associations of killer cell immunoglobulin-like receptor genes with complications of rheumatoid arthritis

We investigated whether killer cell immunoglobulin-like receptor (KIR) genes are risk factor(s) for rheumatoid arthritis (RA) and its clinical manifestations. One hundred and seventy-seven RA patients and 243 healthy individuals were tested for the presence of 11 KIR genes using PCR-SSP method. The frequencies of KIRs in patients with RA were similar to the frequencies in controls. However, RA patients positive for KIR2DL3 and negative for KIR2DS3 had earlier disease diagnosis. Additionally, KIR2DL2 and KIR2DS2 were significantly more frequent among RA patients with extra-articular manifestations and in its subgroup with vasculitis than in controls and in patients without these complications. Furthermore, the frequencies of KIR2DS1 and KIR3DS1 were lower in patients without bone erosions compared with healthy individuals. Relationships between the presence or absence of autoantibodies (rheumatoid factor and anti-cyclic citrullinated peptide) and KIR frequencies were also evaluated, but no significant differences were observed. These results suggest that particular clinical manifestations of RA may have different genetic backgrounds with respect to KIR genotype.     

Haem biosynthesis studied in patients with rheumatoid arthritis

In a study of the urinary excretion of haem precursors in patients with rheumatoid arthritis, iron-deficiency anaemia, and in healthy controls, certain differences were found.In iron-deficiency anaemia the excretion of both porphobilinogen and delta-aminolevulinic acid was increased, whereas in patients with rheumatoid arthritis only the porphobilinogen excretion was increased.A further study on the erythrocyte activity of delta-aminolevulinic acid dehydrase showed a higher activity in the erythrocytes from patients with rheumatoid arthritis compared with healthy controls.     

Anti-MBL autoantibodies in patients with rheumatoid arthritis: prevalence and clinical significance

Occurrence of autoantibodies in patients' sera is the characteristic feature of autoimmune disorders. We assessed the presence of anti-mannose binding lectin (MBL) autoantibodies in the sera of 107 rheumatoid arthritis (RA) patients and 121 control subjects by enzyme immunoassay. Elevated levels of anti-MBL autoantibodies in the sera of RA patients (P<0.0001) was detected for the first time. The ratios of anti-MBL positive in RA patients and controls were respectively 60.7% and 1.65%. Experiments were then designed to understand the functional relevance of these autoantibodies. An inverse correlation of anti-MBL autoantibodies with serum MBL levels (P=0.001) and MBL complex activity (P=0.02) was observed without genetic association between MBL polymorphisms and anti-MBL autoantibody secretion. A significant increase (P=0.038) in the level of anti-MBL autoantibodies was observed in 23 synovial fluid samples in comparison to the serum samples. Moreover, the anti-MBL autoantibodies were found to be more often present in the sera of RA patients (60.75% sensitivity, 98.35% specificity and 0.913 area under the ROC curve) in comparison to the IgM and IgG isotypes of rheumatoid factors (RF). Anti-MBL autoantibodies were still positive in 25.23% RA patients when both the RF isotypes were negative. Also, in RA patients, at all stages of disease activity and joint deformity, anti-MBL autoantibodies were more often present than both the RF isotypes. Therefore, the significant presence of anti-MBL autoantibodies enunciates that anti-MBL autoantibodies might have a diagnostic value; however, more studies are needed to confirm the role of anti-MBL autoantibodies in the diagnosis of rheumatoid arthritis.     

Neutrophil functions in rheumatoid arthritis

Neutrophils play an important role in the pathogenesis of rheumatoid arthritis by accumulation and liberation of active proteolytic enzymes. Despite the active participation of the neutrophils, the patients afflicted with rheumatoid arthritis are prone to multiple infections. We studied neutrophil functions in 20 rheumatoid arthritis patients in active disease and equal number in remission and 20 healthy normal controls. No change in neutrophil function was seen in patients in remission. Phagocytic capacity of the neutrophils in active disease was found to be significantly reduced (p < 0.05). This inversly correlated with the rheumatoid factor (r = -0.128, p = 1). Random migration and chemotaxis was statistically reduced when compared with either healthy controls (p < 0.01) or when compared with patients in remission (p < 0.01). The chemotaxis inhibition was further enhanced by autologus serum (p < 0.05). The serum from patients with active disease also reduced chemotaxis of neutrophils from normal individuals (p < 0.01), indicating reduced cellular response as well as inhibitors in serum. The positive correlation (r = 0.466, p < 0.01) with rheumatoid factor, suggests the inhibitory activity may be due to the circulating rheumatoid factor in the active disease. The postulate that prior saturation of neutrophil receptors with immune complexes lower phagocytosis as well as chemotaxis is sustained. Destruction of chemotaxis receptors by release of various strong oxidative enzymes by neutrophils may also be a factor. Normal leucocytes are seen to take up immunoglobulins from diseases serum but not from normal serum. This uptake of diseased serum may be responsible for reducing the chemotactic and phagocytic function of neutrophils and hence increased incidence of infection in these patients.     

Couples coping with chronic illness: Women with rheumatoid arthritis and their healthy husbands

Effects of a chronic disease, rheumatoid arthritis, upon the psychological adjustment of 103 women and their healthy husbands were examined. Husbands completed scales assessing perceived vulnerability to illness and coping efficacy, burden of caring for their wives, and level of psychological adjustment. Wives completed the Ways of Coping scale, rated attributions about arthritis, and rated criticalness and supportiveness of their husbands. Husbands were also interviewed and their responses coded for critical remarks about the wife. The same variables were used to predict each partner's adjustment in order to compare factors associated with each. Hierarchical regression indicated that negative marital interaction surrounding the wife's illness was a determinant of both partners' psychological adjustment. Apart from this variable, different factors predicted husbands' and wives' mental health. Husbands were most affected by their own perceived vulnerability to disease and coping inefficacy. Wives were most affected by pain severity and how they coped with arthritis.     

Correlative studies of rheumatoid factors and anti-viral antibodies in patients with rheumatoid arthritis.

An analysis of the relationship between the immune response to ubiquitous herpes family viruses, namely Epstein-Barr virus (EBV), cytomegalovirus (CMV), and varicella-zoster virus (VZV) and the presence of rheumatoid factors (RF), which are autoantibodies characteristic of patients with rheumatoid arthritis (RA), was conducted. Antibody profiles (RF, anti-viral antibodies) were monitored in the serum of the RA patients, and in normal individuals. No patient was found to have circulating RF in the absence of anti-viral antibodies. When the patients and normal controls were subdivided according to the presence of serum RF, it was found that when RF were present, the frequency of anti-CMV antibodies, but not anti-EBV or anti-VZV antibodies, was significantly higher (P = 0.02) when compared with RF-negative individuals. The titres of anti-CMV but not anti-VZV antibodies were found to increase in the RA patients with disease duration. To see if these viruses could stimulate RF production in vitro, peripheral blood mononuclear cells (PBMC) isolated from the patients and normal controls were stimulated with viral antigens. PBMC from normal controls, but not from RA patients, appeared to be responsive to viral antigen stimulation and produced RF. These data suggest that the immune response to CMV, to a greater extent than to EBV or VZV, correlates with the presence of RF.     

Tumor necrosis factor locus polymorphisms in rheumatoid arthritis

We examined six polymorphic elements in the tumor necrosis factor (TNF) locus and determined their allelic distribution in 98 Caucasian rheumatoid arthritis patients in comparison with 91 ethnically-matched controls. Polymorphic elements at four biallelic sites were distributed similarly between patients and controls, irrespective of the presence or absence of DR4. Differences were observed between the two groups at the TNFa and TNFe loci, but these were consistent with extended MHC haplotypes known to be present in rheumatoid arthritis patients. Therefore, this study suggests that there is little, if any, independent contribution of the TNF locus to the genetic background for rheumatoid arthritis susceptibility.     

Comparison of antinuclear antibody and rheumatoid arthritis factor test results between two nearby hospitals

Antinuclear antibody and rheumatoid arthritis factor test results were compared between two nearby hospitals of approximately the same size but with different patient populations. There were dramatic differences in percentage of positive results, titers, and patterns (for antinuclear antibody tests) between the two institutions.     

Tryptase is a candidate autoantigen in rheumatoid arthritis

Autoimmune processes have been implicated in the development of rheumatoid arthritis (RA); however, specific autoantigens that play a role in the aetiology of RA have been lacking. In this study, we found that sera from RA patients were particularly immunoreactive against the protein tryptase. Compared with osteoarthritis (OA) patients and healthy controls, RA patients had relatively higher levels of tryptase and concomitant anti‐tryptase antibodies in their synovial tissues and sera. Similarly, synovial fluid from RA patients, but not from OA patients, contained antibodies that recognized tryptase in vitro. In addition, serum tryptase levels in both early and late RA patients significantly correlated with clinical indices usually used to diagnose RA, such as rheumatoid factor, Disease Activity Score using 28 joint counts and autoantibodies against cyclic citrullinated peptide. Our results identify tryptase as a candidate autoantigen involved in the pathogenesis of RA and monitoring its levels may have diagnostic and prognostic value.     

Raising rheumatoid factor cutoff helps distinguish rheumatoid arthritis

The presence of rheumatoid factor (RF) is one of the clinical criteria for the diagnosis of rheumatoid arthritis (RA). The cutoff point of RF assays is usually based on a reference level obtained from normal subjects in the same population as the patients. We evaluated 63 rheumatoid arthritis (RA), 25 other arthritis patients and 110 blood donors. Their rheumatoid factors (RF) ranged from < 9.9 to 2,264, < 9.9 to 262, and < 9.9 to 66 mIU/ml, respectively. The sensitivity at different cutoff points of 15, 20, and 25 mIU/ml was 92.1%, 90.5%, and 88.9%, respectively. The specificity at the same cutoff points was 81.5%, 84.4%, and 85.2%, respectively. Having minimally sacrificed the sensitivity, we recommend using a higher RF cutoff to increase specificity.     

Autoimmunity in myasthenia gravis: a family study

The prevalence of autoantibodies to muscle, epithelial cells of calf thymus, thyroid, gastric parietal cells and antinuclear and rheumatoid factors has been studied in the sera of thirty-two patients with myasthenia gravis and their relatives.

Previous reports of an increased prevalence of autoantibodies in the sera of patients with myasthenia gravis have been confirmed and it has been shown that concurrent reactivity to muscle and thymus is closely correlated with the severity of the myasthenia and the presence of a thymoma, whereas no such correlation occurred with the other antibodies studied. None of the sera from relatives or spouses showed concurrent reactivity with thymus and muscle, and with the exception of one patient with pernicious anaemia, sera from patients with a variety of other diseases were also negative.

A slight increase in the prevalence of autoantibodies to thyroid and gastric components and antinuclear factor was found in first degree relatives of patients with myasthenia gravis; this could be accounted for by their aggregation in a few families.

     

B cells in rheumatoid arthritis

Though its etiology remains unknown thus far, the role that autoimmune processes play in rheumatoid arthritis (RA) pathogenesis has been widely proven. Given the easier accessibility of humoral components, the first feature of this contribution to be recognized has been the occurrence of the so-called rheumatoid factor in a large proportion of RA patients. This antibody recognizes the Fc portion of human IgG. By investigating RA pathologic processes and also through experimental models where immune complexes play a fundamental role, many other autoantibodies have then come to our knowledge to be associated with the disease. Their presence and persistence implies that clones of autoreactive B cells survive and proliferate in RA patients under a continuous stimulation. Whether this is a mechanism of disease initiation or just an epiphenomenon is still unclear but no doubt exists that autoantibodies represent a very useful tool in both diagnostic and prognostic terms. Being much more than simple autoantibody producers, B cells are able to secrete many important cytokines and to efficiently present antigens to T lymphocytes in the synovial environment. All of these functions are essential in the development of RA, and lately have claimed attention as B cell depletion has become a common and effective strategy of treatment in RA.     

B cells in rheumatoid arthritis

Though its etiology remains unknown thus far, the role that autoimmune processes play in rheumatoid arthritis (RA) pathogenesis has been widely proven. Given the easier accessibility of humoral components, the first feature of this contribution to be recognized has been the occurrence of the so-called rheumatoid factor in a large proportion of RA patients. This antibody recognizes the Fc portion of human IgG. By investigating RA pathologic processes and also through experimental models where immune complexes play a fundamental role, many other autoantibodies have then come to our knowledge to be associated with the disease. Their presence and persistence implies that clones of autoreactive B cells survive and proliferate in RA patients under a continuous stimulation. Whether this is a mechanism of disease initiation or just an epiphenomenon is still unclear but no doubt exists that autoantibodies represent a very useful tool in both diagnostic and prognostic terms. Being much more than simple autoantibody producers, B cells are able to secrete many important cytokines and to efficiently present antigens to T lymphocytes in the synovial environment. All of these functions are essential in the development of RA, and lately have claimed attention as B cell depletion has become a common and effective strategy of treatment in RA.