Rheumatoid Factor In Patients Research Articles

AB0170 Anti-cyclic citrullinated peptide and rheumatoid factor in patients with chronic hepatitis b and hepatitis b carriers

BackgroundRheumatoid factor (RF) positivity that may occur in a number of patients with HBV infection poses challenges in terms of differential diagnosis with rheumatoid arthritis (RA). On the other hand,...

Abnormal IgA1 O-Glycosylation in a Multi-ethnic population of IgA Nephropathy Patients in KwaZulu Natal, South Africa.

Abnormal IgA1 O-Glycosylation in a Multi-ethnic population of IgA Nephropathy Patients in KwaZulu Natal, South Africa.

インスリン依存性 (I型) およびインスリン非依存性 (II型) 糖尿病におけるリウマチ因子

インスリン依存性 (I型) およびインスリン非依存性 (II型) 糖尿病におけるリウマチ因子

Significance of Antinuclear Antibodies and Rheumatoid Factor in Patients with Advanced Peripheral Arterial Disease

Objective: To determine whether or not elevated titers of antinuclear antibodies (ANA) and/or rheumatoid factor (RF) are associated with patients with advanced peripheral arterial disease (PAD). Subjects and Methods: A cross-sectional study was done between September 2005 and December 2006. Fifty-eight patients with clinical and angiographic evidence of PAD and 41 controls were studied. Controls had no documented history of peripheral, coronary or cerebral vascular disease. All subjects were screened for metabolic syndrome and C-reactive protein (CRP) as risk factors for peripheral vascular disease. Additionally, all were tested for anti-mitochondrial, anti-neutrophil cytoplasmic and anti-smooth muscle antibodies; those with positive results were excluded. ANA and RF were measured in sera from cases and controls. Results: One case and 3 controls had positive anti-smooth muscle antibodies and were therefore excluded from statistical analysis. Metabolic syndrome was significantly more prevalent in patients than controls (p < 0.05). Mean CRP level was 4.78 ± 7.70 and 2.65 ± 3.86 mg/dl in cases and controls, respectively (p = 0.021). ANA were detected at a titer of ≧1:40 in 6 (10.5%) of the advanced PAD patients but none of the controls; the difference was not statistically significant. RF was less prevalent in cases than controls (p < 0.05). Conclusion: RF and ANA do not appear to be associated with PAD in a Kuwaiti population.

Therapeutic strategy and significance of serum rheumatoid factor in patients with rheumatoid arthritis during infliximab treatment

To predict the response of patients with rheumatoid arthritis (RA) to infliximab, patient profile and laboratory findings were compared to determine whether there was any association with the clinical course of the disease, and the clinical significance of serum rheumatoid factor (RF) in the response to this treatment was considered. Sixty-two RA patients were treated with infliximab, 87.9% of whom were positive for RF. At baseline and 12 months after the start of treatment, RF titers were significantly lower in the low-CRP group (CRP at 12 months<0.3 mg/dl) compared with that in the high-CRP group (CRP at 12 months >1.5 mg/dl). Furthermore, at baseline and 12 months, RF titers were significantly lower in the good-CRP-response group (DeltaCRP>or=1.5 mg/d) compared with the poor-CRP-response group (DeltaCRP<or=0.3 mg/d). The percent changes in RF and CRP from baseline were correlated throughout the clinical course. The duration of disease in good-CRP-response group was shorter than that in poor-CRP-response group significantly. The rate of positivity for HLA-DR4 in good response group tends to be higher than that in poor-CRP-response group. We concluded that several factors, including disease duration, positivity for HLA-DR4, and the serum RF titer at baseline, might predict the patient response to infliximab.

Association of Ultrasonographic Findings of Synovitis With Anti-Cyclic Citrullinated Peptide Antibodies and Rheumatoid Factor in Patients With Palindromic Rheumatism During Active Episodes

The purpose of this study was to investigate whether the presence of ultrasonographic findings of synovitis is associated with the presence of anti-cyclic citrullinated peptide (CCP) antibodies and rheumatoid factor (RF) in patients with palindromic rheumatism (PR) during active episodes. Clinically involved regions of 84 patients with PR during active episodes were examined with high-resolution ultrasonography. Serum levels of anti-CCP antibodies were determined by an enzyme-linked immunosorbent assay, and RF levels were measured by nephelometry. Thirty patients (36%) had ultrasonographic findings of synovitis during active episodes. Significantly higher positive rates of anti-CCP antibodies and RF were observed in patients with PR who had ultrasonographic findings of synovitis compared with those who had no ultrasonographic findings of synovitis (26.7% versus 5.6%; odds ratio, 6.18; P < .05; and 30.0% versus 5.6%; odds ratio, 7.29; P < .01, respectively). The intraobserver and interobserver agreement for the detection of synovitis and Doppler signals by ultrasonographic assessment was excellent. Ultrasonography is a reliable method for assessing the presence of synovitis in patients with PR during active episodes. The ultrasonographic findings of synovitis are associated with the presence of anti-CCP antibodies and RF in patients with PR.

The role of Chloroquine phosphate on rheumatoid factor in patients with knee osteoarthritis

Background: Osteoarthritis (OA) is disorder of diarthrodial joints characterized clinically by pain and functional limitation. Rheumatoid factor (RF) represents one of routine laboratory tests that done for all patients have joint complaints. Chloroquine phosphate (CQP) is a disease modifying antirheumatic drug (DMARD) used for patients suffer from knee osteoarthritis (KOA) in order to reduce their RF value and improves the disease status.Objective: To evaluate the effect of chloroquine phosphate on rheumatoid factor (RF) level in serum of patients with knee osteoarthritis KOA) Design: case report.Subjects and methods: RF value were assessed quantitatively by ELISA technique before and after treatmtnt for a total of fifty five patients with KOA (30 femal and 25 male) their age ranged from (50-66 years) selected randomly from out patient clinic in Baghdad Teaching Hospital , Medical City Baghdad; suffering from KOA. All patients were treated with oral dosage form of CQP for one month twice daily. Results: Mean serum RF level was significantly reduced (p<0.05) in serum of patients after treatment with CQP for one month.Conclusion:CQP is a disease modifying antirheumatic drug (DMARD) used for patients suffering from KOA in order to reduce their RF value and improves the disease status.

Anti-citrullinated protein antibody and rheumatoid factor in patients with end-stage renal disease

Patients with end-stage renal disease (ESRD) and on hemodialysis (HD) are at increased risk for developing rheumatoid arthritis (RA), as a result of defective immunity. Our aim was to examine if ESRD and the length of HD treatment impact the clinical utility of antibodies to cyclic citrullinated peptides (anti-CCP) and rheumatoid factor (RF) as diagnostic tools for RA. We included 94 subjects in our study: 37 healthy volunteers and 57 patients with ESRD who had been undergoing HD for 1-12 years, and without confirmed RA. In order to test our hypothesis, we measured and correlated anti-CCP and RF as laboratory markers of RA. Our study showed that there is no significant difference between values for anti-CCP (p=0.11) and RF (p=0.98) in control subjects as well as in patients undergoing HD, regardless of the length of time that patients had been undergoing HD treatment. Our study indicates that HD does not impair the specificity of anti-CCP and RF for RA in patients where the disease has not yet developed. Future prospective studies may show whether there is any use in determinating RF, and especially anti-CCP, as early predictors of RA in patients with ESRD who are at greater risk of developing this condition.

The diagnostic value of anti-cyclic citrullinated peptide antibodies and rheumatoid factor in patients with rheumatoid arthritis

Objective: To identify the diagnostic value of anti-cyclic citrullinated peptide (anti-CCP) antibodies and rheumatoid factor (RF) in patients with rheumatoid arthritis (RA). Methods: Serum levels of anti-CCP antibodies were determined by enzyme-linked immunosorbent assay, and levels of RF were determined by nephelometry in 145 patients with RA and 75 patients with non-RA rheumatic diseases. Results: Among the 145 patients with RA, 119 patients (82.1%) tested positive for anti-CCP antibodies, and 116 patients (80.0%) tested positive for RF. The sensitivity, specificity, positive predictive value, and negative predictive value of anti-CCP antibodies for diagnosing RA were 82.1%, 88.0%, 93.0%, and 71.7% respectively. Those for RF were 80.0%, 62.7%, 81.1%, and 61.0% respectively. The presence of either anti-CCP antibodies or RF increased sensitivity to 88.3%, and when they both were present, the specificity increased to 94.7%. The positive rates for anti-CCP antibodies in the RF-positive RA, RFnegative RA, and non-RA patients were 93.1%, 37.9%, and 12.0% respectively. Conclusion: With its high sensitivity and specificity, the anti-CCP antibodies assay is a useful test for diagnosing RA. The use of anti-CCP antibodies and RF in combination further increases the diagnostic value for RA.

Impact of Treatment with Infliximab on Anticyclic Citrullinated Peptide Antibody and Rheumatoid Factor in Patients with Rheumatoid Arthritis

To investigate the impact of infliximab treatment on anticyclic citrullinated peptide (anti-CCP) antibody and rheumatoid factor (RF) levels in patients with rheumatoid arthritis (RA). Sera from 33 RA patients receiving infliximab and disease modifying antirheumatic drugs were tested for anti-CCP antibody, IgA-, IgG- and IgM-RF using a commercially available semiquantitative ELISA at baseline, 30 and 54 weeks after treatment. The serum levels of anti-CCP antibody and IgA-RF decreased significantly after 30 weeks (P = 0.002 and 0.024); however, the decrease was not significant at week 54 (P = 0.147 and 0.207). The decrease in IgG-RF level was not significant at 30 and 54 weeks (P = 0.059 and 0.097). IgM-RF levels, however decreased significantly at 30 and 54 weeks (P = 0.002 and 0.004). A strong correlation between anti-CCP and IgA-, IgG- and IgM-RF was observed at baseline (r(s) = 0.48, 0.43, 0.65, P = < 0.05) and after infliximab treatment at 30 (r(s) = 0.45, 0.46, 0.62, P = < 0.05) and 54 (r(s) = 0.49, 0.45, 0.60, P = < 0.05) weeks. Treatment with infliximab results in decreased anti-CCP antibody and IgA-RF early in the course of therapy that is not sustained. IgM-RF declines and remains decreased for at least 54 weeks. Investigations in larger cohorts of RA patients (especially early RA) with longer follow-up are needed to assess the impact of specific therapeutic interventions on anti-CCP antibody and RF levels and the relationship of their levels to disease activity.

Diagnostic value of anti-human citrullinated fibrinogen ELISA and comparison with four other anti-citrullinated protein assays

We studied the diagnostic performance of the anti-human citrullinated fibrinogen antibody (AhFibA) ELISA for rheumatoid arthritis (RA) in a consecutive cohort (population 1) and evaluated the agreement between the AhFibA ELISA and four other assays for anti-citrullinated protein/peptide antibodies (ACPAs) as well as rheumatoid factor in patients with longstanding RA (population 2). Population 1 consisted of 1024 patients with rheumatic symptoms; serum samples from these patients were sent to our laboratory for ACPA testing within the context of a diagnostic investigation for RA. Ninety-two of these patients were classified as having RA according to the American College of Rheumatology criteria and 463 were classified as non-RA patients. Population 2 consisted of 180 patients with longstanding RA and was used to assess agreement and correlations between five ACPA assays: anti-cyclic citrullinated peptide (CCP)1 and anti-CCP2 antibodies were detected using a commercially available ELISA, AhFibA using ELISA, and anti-PepA and anti-PepB antibodies using line immunoassay. Applying previously proposed cut-offs for AhFibA, we obtained a sensitivity of 60.9% and a specificity of 98.7% in population 1. Receiver operating characteristic curve analysis could not detect a significant difference in diagnostic performance between the AhFibA ELISA and anti-CCP2 assay. Performing a hierarchical nearest neighborhood cluster analysis of the five different ACPA assays in population 2, we identified two clusters: a cluster of anti-pepA, anti-pepB and anti-CCP1, and a cluster of AhFibA and anti-CCP2. In conclusion, we found that AhFibA and anti-CCP2 antibodies had similar diagnostic performance. However, disagreement between ACPA tests may occur.

Anti-cyclic citrullinated peptide autoantibodies in IgM rheumatoid factor-positive patients

Background Antibodies to citrullinated proteins have been described in patients with RA and these appear to be the most specific markers of the disease. The objective of this study was to analyse the improvement in diagnostic accuracy of anti-cyclic citrullinated peptide autoantibodies and IgA rheumatoid factor in patients with clinical suspicion of RA and who were IgM rheumatoid factor-positive. Anti-CCP antibodies were measured with three different second-generation enzyme immunoassays. Methods We chose 133 serum samples with IgM RF levels greater than 20 IU/mL sent to our Laboratory from Specialized Care Units. Subsequently, patients were classified according to their clinical records. Eighty-seven had rheumatoid arthritis and 46 had other diseases. In all samples anti-CCP and IgA RF were measured by the corresponding ELISAs. Results Comparison of the three anti-CCP second-generation ELISAs revealed differences between them. Likewise, clinical performances in terms of sensitivity, specificity, and positive and negative likelihood ratios were different. In patients with IgM RF higher than 20 IU/mL, anti-CCP antibodies increased the clinical efficiency of IgM RF and offered better performance as compared with IgA RF. Conclusions The use of anti-CCP antibodies affords good clinical efficiency and modifies the pre-test probability of the occurrence of RA in patients with IgM rheumatoid factor higher than 20 IU/mL.

Serum oxidized low-density lipoproteins in rheumatoid arthritis.

The aim of this study was to measure serum oxidized low-density lipoprotein (Ox-LDL) levels in patients with rheumatoid arthritis (RA) or systemic lupus erythematosus (SLE) and to identify any association with clinical variables. We studied 126 female patients (27 with active RA, 27 with inactive RA, 72 with SLE). One hundred fifteen age-matched healthy women (76 for RA, 39 for SLE) with no clinical or laboratory evidence of disease served as normal controls. Serum Ox-LDL levels were measured with a commercial enzyme-linked immunosorbent assay kit (Mercodia, Sweden). The serum Ox-LDL levels were significantly higher in patients with active RA (P<0.05) or SLE (P<0.01) than age-matched controls and significantly higher in patients with active RA than with inactive RA (P<0.01). The levels of serum total cholesterol and LDL were significantly lower in patients with RA than in age-matched controls (P<0.01). There was no correlation among serum Ox-LDL levels and inflammatory markers (erythrocyte sedimentation rate, C-reactive protein) or rheumatoid factors in patients with RA. Compared with healthy women, those with SLE or active RA had increased serum Ox-LDL levels, which may contribute to the increased risk of cardiovascular disease in this patient group.

Association of Human Leukocyte Antigen Class II Genes with Autoantibody Profiles, but not with Disease Susceptibility in Japanese Patients with Systemic Sclerosis.

To examine the role of human leukocyte antigen (HLA) class II genes in the development of systemic sclerosis (SSc) as well as in the clinical and serologic expression of SSc in patients. HLA-DRB1, DRB3, DRB4, DQB1, and DPB1 alleles were determined by genotyping; and serum antinuclear antibodies were identified using indirect immunofluorescence, double immunodiffusion and immunoprecipitation. One hundred and five Japanese patients with SSc and 104 race-matched healthy controls. Frequencies of DRB1 and DQB1 alleles were not different between SSc patients and healthy controls, while DPB1*0901 was marginally increased in SSc patients. In contrast, SSc-related autoantibodies were closely associated with the clinical features. HLA class II genes were detected as follows: anti-DNA topoisomerase I antibody with diffuse cutaneous involvement, pulmonary fibrosis, and DRB1*1502-DQB1*0601-DPB1*0901; anti-U1RNP antibody with overlapping features of lupus and/or myositis and DRB1*0401/*0802-DQB1*0302; and anticentromere antibody with limited cutaneous involvement and DRB1*0101-DQB1*0501-DPB1*0402. In the analysis of the association of HLA class II and the clinical features in SSc patients significant differences were obtained only for the increased frequencies of arthritis and rheumatoid factor in patients with DRB1*0405 compared to those without. HLA class II genes strongly influence the production of SSc-related autoantibodies rather than the development of SSc. In addition, SSc is a composite disease of distinctive subsets defined by serum autoantibodies, which have specific clinical and HLA class II associations.

Rheumatoid hyperviscosity: analysis of a patient with intermediate complexes that block other autoantibodies and a review of the literature

Objectives: To report a patient whose rheumatoid arthritis presented withhyperviscosity syndrome, analyze this patient's rheumatoid factor, and review the previously reported patients. Methods: Immunofluorescence for antinuclear antibodies, double immunodiffusion,enzyme-linked immunosorbent assay, and size exclusion chromatography were used before and after plasmapheresis to study the patient's rheumatoid hyperviscosity. A systematic Medline search of rheumatic illnesses, hyperviscosity, and polyclonal gammopathy and references in identified papers was used to identify previously reported patients. Results: Similar to several previous patients, this patient's sera contained bothIgG and IgM rheumatoid factor and abundant intermediate complexes. Other autoantibodies, either from the patient or from other patients, were masked by rheumatoid factor or intermediate complexes from the reported patient's sera. Rheumatic hyperviscosity is seen uncommonly, being reported in only 18 patients with rheumatoid arthritis and nine with other rheumatic illnesses. Conclusions: There are two mechanisms by which rheumatoid factor can leadto hyperviscosity, both of which require large amounts of rheumatoid factor. Rheumatoid hyperviscosity must be recognized because this life-threatening syndrome usually can be successfully treated with plasmapheresis acutely and immunosuppressives for long-term control.

Selective increase of IgA rheumatoid factor in patients with gluten sensitivity.

An increased prevalence of raised autoantibodies, including rheumatoid factor, has been reported in patients with gluten sensitivity. However, rheumatoid factor has only been measured in small groups of patients and the findings have been conflicting. In this study IgM, IgG and IgA rheumatoid factor was measured in 89 patients with dermatitis herpetiformis and 22 patients with coeliac disease and compared with 89 normal controls. There was an increased prevalence of elevated IgA rheumatoid factor in the patients with dermatitis herpetiformis (13.5%; p = 0.036) and coeliac disease (18.2%; p = 0.078), while no such increase was found for the IgM or IgG rheumatoid factor isotypes. This selective increase of IgA rheumatoid factor suggests that rheumatoid factor production in patients with gluten sensitivity primarily results from immunological activation in the gut mucosa.

Medical decision making based on inductive learning method

Medical decision making based on inductive leaming has been studied in order to collect experience necessary for practical use of such methods in clinical and epidemiological work. The decision trees have been constructed by using the modified Quinlan's approach based on choosing relevant attributes according to their informativity. An inductive leaming software tool, ASSISTANT Professional, has been used for experimenting. The variability in results has been studied under varying leaming conditions. Two sets of data have been chosen for learning experiments: from a study on rheumatoid factors in patients with rheumatoid arthritis, and from an epidemiological investigation of ageing. The results of this study indicate the necessity to determine inductive learning parameters for each paricular problem. The pruning procedure is always recommended as it eliminates redundant elements in the tree. In problems with greater number of attributes, howerer, pruning itself is not guaranteeing satisfactory solutions. Interventions like the change of the minimal weight threshold might improve the situation. If these precautions are met, the method of inductive learning seems to be a useful guide in practical clinical and epidemiological decisions.

Rheumatoid factors isolated from patients with autoimmune disorders are derived from germline genes distinct from those encoding the Wa, Po, and Bla cross-reactive idiotypes.

To better understand the structural basis for rheumatoid factor activity, the nucleotide sequence of the light chain variable regions of nine human monospecific IgM rheumatoid factors were analyzed. Rheumatoid factors were isolated from three patients with rheumatoid arthritis, a patient with systemic lupus erythematosus, and a normal individual. The VL gene segments used by these rheumatoid factors are not as restricted as previous work on mixed cryoglobulin rheumatoid factors had suggested. Each of the different VK families is represented and there are two examples where a V lambda gene segment is used. Molecules with structures similar to those of the Wa and Po CRI, characteristic of mixed cryoglobulin rheumatoid factors, are not common among these rheumatoid factors isolated from patients with rheumatoid arthritis. While there are clear examples of rheumatoid factors that are direct copies of germline genes, most of the sequence data suggest that the processes of antigenic selection and somatic mutation contribute significantly to the generation of monospecific rheumatoid factors in patients with autoimmune disease.

Defective Helper T Cell Function in IgM Rheumatoid Factor Synthesis in Patients with Ankylosing Spondylitis

Despite chronic inflammation and the presence of hypergammaglobulinemia, rheumatoid factor (RF) is rarely found in the blood of patients with ankylosing spondylitis (AS). We used ELISA to compare spontaneous and pokeweed mitogen (PWM)-induced IgG, IgM and IgM rheumatoid factor (IgM-RF) production in normals and in patients with rheumatoid arthritis (RA) and AS. The IgG and IgM synthesis in these three groups did not differ. However, the IgM-RF level in PWM-induced mononuclear cell cultured supernatants of AS was significantly decreased, compared with normal and RA patients. Furthermore, mixing experiments by co-culture of normal T or B cells with patient's B or T cells in the presence of PWM revealed a deficiency of the helper T cell function in patients with AS. These results illustrate the cellular mechanism of the seronegativity of the rheumatoid factor in patients with ankylosing spondylitis.

Participation of antigens related to the psoriasis associated antigen, pso p27, in immune complex formation in patients with ankylosing spondylitis.

Analysis of five serum samples and three synovial fluids from patients with ankylosing spondylitis (AS) and five serum samples from healthy blood donors for the presence of antibodies cross reacting with the Fc part of rabbit IgG (rheumatoid factors (RFs] using an isotype specific, enzyme linked immunosorbent assay (ELISA) showed only insignificant amounts of free RFs, while IgG RFs were observed in alkaline dissociated circulating immune complexes (CICs). Only insignificant amounts of free antibodies reacting with the psoriasis associated antigen pso p27 could be detected in the samples, while extensive amounts of IgG antibodies and moderate amounts of IgM antibodies reacting with pso p27 were detected in alkaline dissociated CICs from the patients. Pso p27 has been reported to share a common determinant with the Fc part of human IgG. Removal of the RF activity from the CICs of patients with AS by absorption with IgG resulted in a decrease of the anti-pso p27 activity. Monoclonal anti-pso p27 antibodies in a sandwich ELISA were used to detect antigens cross reacting with pso p27. A positive reaction was observed in all serum CICs and in one of the synovial fluid CICs. The data indicate that antigens related to pso p27 participate in CIC formation in AS and may also be responsible for the elicitation of rheumatoid factors in patients with AS.