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ID PMID Title PublicationDate abstract
15700029 The role of substance P in microvascular responses in murine joint inflammation. 2005 Apr 1. Rheumatoid arthritis is a serious, inflammatory disease of the distal joints that has a possible neurogenic component underlying its pathology. 2. Substance P (SP), an endogenous neuropeptide that acts upon the neurokinin 1 (NK(1)) receptor, is released from sensory nerves and is involved in neurogenic inflammation. 3. In this study, we have developed novel techniques to determine the contribution of SP to microvascular responses in a model of complete Freund's adjuvant (CFA)-induced arthritis in NK(1) knockout mice. 4. Detailed analysis in normal mice revealed that CFA (20 microg i.art.)-induced plasma extravasation was raised from 18 to 72 h, when compared with intravascular volume. By comparison, knee swelling was sustained for 3 weeks. Neutrophil accumulation mirrored plasma extravasation. SP (10 pmol i.art.) caused significant acute plasma extravasation, but not other parameters, in wild type (WT), but not NK(1) knockout mice. CFA (10 microg i.art.) induced a significantly decreased intravascular volume, presumably due to decreased blood flow, at early time points (5 and 7 h) in WT but not NK(1) knockouts. Otherwise, similar responses in WT and NK(1) knockout mice were observed. However, injection of SP into CFA-pretreated joints caused a significant enhancement of plasma extravasation and knee swelling in the WT but not NK(1) knockouts. 5. In conclusion, the present study has used novel techniques in WT and NK(1) knockout mice to show that SP can modulate vascular tone and permeability in the inflamed joint via activation of the NK(1) receptor and that SP-induced responses are more pronounced where pre-existing inflammation is present.
16317826 Abatacept as add-on therapy for rheumatoid arthritis. 2005 Sep Abatacept is a co-stimulation blocker that inhibits T-cell activation and interrupts the process leading to inflammation in rheumatoid arthritis. Patients with severe arthritis who took abatacept with at least one other disease-modifying antirheumatic drug in six and 12-month clinical trials demonstrated statistically significant improvement in tender, swollen joints and other clinical measures compared with placebo. Mild to moderate adverse events included headache, nasopharyngitis, hypertension and back pain. The adverse events were similar to those seen in placebo groups. Abatacept should not be used in combination with other biologic agents because of reported increased rates of serious adverse events, including serious infections. With its different mechanism of action, abatacept may be an alternative add-on therapy for patients with an inadequate response to other arthritis therapies.
15917104 Sparing of age-related macular degeneration in rheumatoid arthritis. 2005 Aug Age-related macular degeneration (AMD), for which inflammatory changes have been demonstrated, is the commonest cause of blindness in the elderly. We compared the prevalence of AMD in a prospectively followed cohort of rheumatoid arthritic (RA) patients from Saskatchewan with published data from four racially similar general populations. For individuals 65 years or older, only three cases of AMD were identified in the Saskatchewan cohort of 993 RA patients (0.2% prevalence). This compares with 67 out of 1955 subjects in the Beaver Dam survey (prevalence 3.43%); 101 out of 4071 in the Rotterdam survey (prevalence 2.48%); and 63 out of 1950 in the Blue Mountains survey (prevalence 3.23%). For individuals 75 years or older, only two cases out of 497 were identified in the RA cohort (prevalence 0.40%), compared with 516 cases out of 13,900 in the United Kingdom survey (prevalence 3.72%). Patients with RA appear to be relatively spared from AMD. We hypothesize that this results from long term antiinflammatory treatment. Genetic or environmental factors could also be responsible.
16984939 Formative research in clinical trial development: attitudes of patients with arthritis in 2007 Apr In preparation for randomised controlled trials (RCTs) of disease-modifying antirheumatic drugs in patients with early inflammatory arthritis (EIA), formative research was conducted to enhance the design of such trials. The objectives of this research were to (1) determine patients' educational needs as they relate to the necessary elements of informed consent; and (2) assess patients' interest in enrolling in a hypothetical prevention trial. In-depth interviews were conducted with nine patients. Seven patients were women and all but one white. The mean age was 48 years. During the 4-month enrolment period, only three patients with EIA were identified; six patients with longer duration of symptoms were also interviewed. Most patients were able to express the primary aim of a hypothetical prevention trial presented. Factors cited by patients favouring enrolment were potential for direct medical benefit and knowledge that they would be withdrawn from the trial if they developed symptoms. Factors cited by patients against enrolment were the inclusion of a placebo and general uncertainty regarding treatment required by the RCT design. Pending larger-scale empirical projects to explore patients' attitudes about prevention trials, small-scale formative research in advance of such trials ought to be conducted.
16703417 IL-20: biological functions and clinical implications. 2006 Sep IL-20 belongs to the IL-10 family and plays a role in skin inflammation and the development of hematopoietic cells. Little is known about its other biological functions and clinical implications, however. Updated information about IL-20, such as its identification, expression, receptors, signaling, biological activities, and potential clinical implications, is illustrated in this review based on our research and on data available in the literature. Our studies of IL-20 show that it is a pleiotropic cytokine with potent inflammatory, angiogenic, and chemoattractive characteristics. Inflammation and angiogenesis are essential for the pathogenesis of rheumatoid arthritis and atherosclerosis. Based on in vitro data and clinical samples, we demonstrated that IL-20 is involved in the diseases of rheumatoid arthritis and atherosclerosis. In addition, we found in our studies that IL-20 signaled through different molecules in several cells. The present review presents the clinical implications of IL-20 in rheumatoid arthritis and atherosclerosis. It may provide new therapeutic options in the future.
15642132 p53 tumor suppressor gene mutations in fibroblast-like synoviocytes from erosion synovium 2005 Abnormalities in the p53 tumor suppressor gene have been detected in rheumatoid arthritis (RA) and could contribute to the pathogenesis of chronic disease. To determine whether synoviocytes from invasive synovium in RA have an increased number of mutations compared with non-erosion synoviocytes, p53 cDNA subclones from fibroblast-like synoviocytes (FLS) derived from erosion and non-erosion sites of the same synovium were examined in patients requiring total joint replacement. Ten erosion FLS lines and nine non-erosion FLS lines were established from nine patients with RA. Exons 5-10 from 209 p53 subclones were sequenced (114 from erosion FLS, 95 from non-erosion FLS). Sixty percent of RA FLS cell lines and 8.6% of the p53 subclones isolated from FLS contained p53 mutations. No significant differences were observed between the erosion and non-erosion FLS with regard to the frequency or type of p53 mutation. The majority of the mutations were missense transition mutations, which are characteristic of oxidative damage. In addition, paired intact RA synovium and cultured FLS from the same joints were evaluated for p53 mutations. Matched synovium and cultured synoviocytes contained p53 mutations, although there was no overlap in the specific mutations identified in the paired samples. Clusters of p53 mutations in subclones were detected in some FLS, including one in codon 249, which is a well-recognized 'hot spot' associated with cancer. Our data are consistent with the hypothesis that p53 mutations are randomly induced by genotoxic exposure in small numbers of RA synoviocytes localized to erosion and non-erosion regions of RA synovium. The determining factor for invasiveness might be proximity to bone or cartilage rather than the presence of a p53 mutation.
17088540 An essential role of NF-kappaB in the "tumor-like" phenotype of arthritic synoviocytes. 2006 Nov 14 A hallmark of rheumatoid arthritis is the formation of an aggressive, tumor-like structure called pannus that erodes the joint. A major cellular component of the pannus is the fibroblast-like synoviocyte (FLS), whose morphology strikingly resembles that of a transformed cell, but underlying mechanisms of this "transformation" are not known. Here, using animal models of rheumatoid arthritis, we show that arthritic FLS contain a substantial (>30%) fraction of bone marrow-derived precursors that can differentiate in vitro into various mesenchymal cell types, but inflammation prevents the multilineage differentiation. We show that the transcription factor NF-kappaB plays the key role in the repression of osteogenic and adipogenic differentiation of arthritic FLS. Furthermore, we show that specific activation of NF-kappaB profoundly enhances proliferation, motility, and matrix-degrading activity of FLS. We thus propose that arthritic FLS are mesenchymal stem cells whose differentiation is arrested at early stages of differentiation by activation of NF-kappaB.
17009227 Influence of male sex on disease phenotype in familial rheumatoid arthritis. 2006 Oct OBJECTIVE: To examine sex differences in clinical, demographic, and genetic characteristics among a large cohort of patients with familial rheumatoid arthritis (RA). METHODS: We studied 1,004 affected members of 467 Caucasian multicase RA families recruited from the North American Rheumatoid Arthritis Consortium. Standardized information about demographic and clinical characteristics was collected from all patients. Affected individuals also underwent radiography of the hands and were genotyped for markers in the HLA region. Sex differences were assessed using contingency table analysis (for categorical variables) and Student's t-tests for (continuous variables), and by multivariate logistic and linear regression analysis. RESULTS: Male patients had a significantly later onset of RA, were more likely to be seropositive for RF, and had significantly higher titers of anti-cyclic citrullinated peptide (anti-CCP) antibodies compared with female patients, even after adjustment for covariates in multivariate analyses. Male patients were also significantly more likely to have a history of smoking and to be HLA-DRB1 shared epitope (SE) positive. Interestingly, female patients with an affected male sibling had significantly higher titers of anti-CCP antibodies and were more likely to be SE positive compared with female patients without affected male siblings. Multivariate analyses indicated that the presence of the SE did not fully explain the increased anti-CCP antibody titers observed in these families. CONCLUSION: Sex has an important influence on the disease phenotype in RA, including the age at disease onset and autoantibody production. Furthermore, families with affected male members are characterized by higher titers of autoantibodies, particularly anti-CCP antibodies. Our results indicate that these findings are not fully explained by differences in exposure to tobacco smoke, presence of the HLA-DRB1 SE, or other HLA region genetic variation. Thus, other genetic or nongenetic factors also contribute to sex differences in the RA phenotype.
15934119 Arthritis and employment: an examination of behavioral coping efforts to manage workplace 2005 Jun 15 OBJECTIVE: To examine ways in which individuals with arthritis manage their employment and health by focusing on the type and determinants of diverse behavioral coping strategies used to manage activity limitations, and to examine the relationship between coping behaviors and participation in employment. METHODS: The study group comprised 492 patients with osteoarthritis or rheumatoid arthritis. All participants were employed, and all participants were administered an in-depth, structured questionnaire. The study used an inductive approach and distinguished among 4 categories of coping behaviors as follows: adjustments to time spent on activities; receipt of help; modification of behaviors; and anticipatory coping. RESULTS: Fewer coping behaviors were reported at the workplace than outside of the workplace. Anticipatory coping was used most often in the workplace. Workplace activity limitations were related to increased reports of all types of coping. Women, those with more joints affected, and people expecting to remain employed reported more anticipatory coping. Expectations of continued employment were also related to modifications of activities, as was longer disease duration and discussing arthritis with one's employer. Help from others was associated with talking to an employer and positive job perceptions. Compared with work, reports of a greater number of coping behaviors used at home were associated with changes in overall work participation (e.g., absenteeism). CONCLUSION: These results expand our understanding of the experience of having a chronic illness and working and highlight the ways in which people accommodate to workplace limitations by using a variety of different behavioral coping efforts to remain employed.
16612602 [Magnetic resonance imaging of the hand in rheumatoid arthritis. New scientific insights a 2006 May Magnetic resonance imaging (MRI) is a sensitive diagnostic modality for the detection of inflammatory changes in peripheral joints. Nevertheless, the widespread clinical use of MRI in assessing patients with early rheumatoid arthritis is still hampered by the technical complexity and higher cost of MRI compared with conventional radiography. This overview summarizes the results of recent research and gives practical tips on how to perform MRI of the hands. The authors present an MR protocol for hand imaging, discuss the pros and cons of low-field MR scanners, and outline pitfalls and artifacts. The MRI changes associated with rheumatoid arthritis such as synovitis, tenosynovitis, erosions, and bone marrow edema are described including their prognostic significance. The proven facts on the validation and grading of MR changes in rheumatoid arthritis are summarized. Finally, the role of MRI in the differential diagnosis of arthritis is critically discussed.
15909087 [Four-year observation of etanercept therapy for rheumatoid arthritis in a single German c 2005 May The tumor necrosis factor blocking agent etanercept is effective in the treatment of chronic inflammatory diseases. Previously published studies provided no evidence for an elevated frequency of severe adverse events under therapy. The present work documents efficacy and safety of long-term treatment with etanercept up to four years in 29 patients with rheumatoid arthritis in single German study center. Follow-up examinations were conducted at monthly intervals. The response was assessed in an intention-to-treat analysis (last observation carried forward) according to the ACR and EULAR criteria. The evaluation is based on 95 patient years, the median observation period was 50 (4-52) months. After four years, 21 patients were still in the study. Reasons for study dropouts were inefficacy (n=3), severe adverse events (n=1), long distance to study center (n=2), scheduled surgery (n=1), and desire for pregnancy (n=1). Morning stiffness, the number of painful and swollen joints, C-reactive protein, erythrocyte sedimentation rate, and DAS28 significantly decreased within 6 months. At their most recent visit, 26 patients (90%) had achieved the ACR20, 17 patients (59%) the ACR50, and 6 patients (21%) the ACR70 criteria. Subject to the EULAR criteria, 14 patients (48%) responded well and another 12 patients (41%) moderately well. Severe adverse events occurred in the form of a sigma perforation with subsequent sepsis (week 17), suture insufficiency (twice) following rupture of an Achilles tendon (weeks 3 and 9), pneumonia (week 121), and breast cancer (week 197). In our patients, long-term treatment with etanercept continued to be effective and safe up to four years. Severe adverse events were rare and not more frequent than expected. For the detection of uncommon or late occurring severe adverse events under the treatment with biologic agents, documentation in central registers should be encouraged.
17199103 [The role of oxidative stress in the etiopathogenesis of rheumatoid arthritis]. 2006 Numerous scientific investigations confirmed the occurrence of oxidative stress in rheumatoid arthritis patients. There is evidence demonstrating elevated levels of oxidative stress markers and oxidative damage caused by reactive oxygen species (ROS) to lipids, proteins, sugars, and DNA, as well as a significant decrease in total antioxidant capacity, which protects the organism against ROS activity. Extensive ROS production can significantly accelerate the process of articular cartilage damage. It is believed that many disease-modifying anti-rheumatic drugs (DMARDs) affect oxidative stress, although there has been insufficient research to confirm such a relationship.
16539820 Anti-Ro/SSA antibodies in rheumatoid arthritis: clinical and immunologic associations. 2006 Jan OBJECTIVE: To assess the prevalence of anti-Ro/SSA in RA and to analyse clinical and serological features of anti-Ro/SSA positive patients with RA. METHODS: 195 consecutive patients affected by RA were studied by counterimmunoelectrophoresis and ELISA for the detection of anti-Ro/SSA antibodies. Anti-Ro were found in 12 patients, with a prevalence of 6%. These 12 patients were pooled with other 15 patients known to have anti-Ro/SSA antibodies and RA, in order to evaluate their clinical and laboratory features. RESULTS: Anti-Ro positive patients showed a common pattern of joint involvement at onset and a comparable progression of disease compared to anti-Ro negative subjects. In addition, extra-articular manifestations (such as xerophthalmia, xerostomia, scleritis, oral ulcers and amyloidosis) and peculiar autoantibody profile (hypergammaglobulinemia, anti-dsDNA and AMA) were found significantly associated to anti-Ro/SSA positivity. Even though DMARDs withdrawals were more frequently detected in anti-Ro/SSA patients, especially when using gold salts, no statistical difference between the two groups was detected. In addition, anti-TNFalpha treatment did not cause further progression of autoimmunity neither on laboratory nor on clinical ground. CONCLUSION: Anti-Ro/SSA can be detected in about 6% of patients affected by RA. These patients presented a peculiar clinical picture characterised by extra-articular manifestations some of which are known to be anti-Ro/SSA correlated, while others are more disease-specific (amyloidosis, episcleritis). Anti-Ro/SSA are significantly associated with other autoantibodies not specific for RA such as anti-dsDNA and AMA. Treatment with anti-TNF drugs did not cause further progression of autoimmunity neither on laboratory nor on clinical ground.
16473751 In vivo dc and ac measurements at acupuncture points in healthy and unhealthy people. 2006 Mar OBJECTIVES: The aim of this work was to compare in vivo measurements of direct current (dc) and alternating current (ac) obtained from acupuncture points in Ukrainian and Mexican residents. METHODS: Measurements were made using the method of Voll. The participants were 43 healthy Ukrainian and 71 healthy Mexican residents aged between 20 and 30 years, as well as 24 Mexican patients with a clinical diagnosis of rheumatoid arthritis and 14 patients with a clinical diagnosis of allergy. RESULTS: The results showed that dc measurements are not directly applicable to different populations. Thus, the dc resistance of the acupuncture points in the Mexican participants was 4-5 times larger than in the Ukrainians. In contrast, the capacitance of the two groups did not differ by more than 25%. CONCLUSIONS: Impedance measurements from acupuncture points can be used as an efficient and prompt non-invasive method for diagnostic purposes.
16670828 Predictive value of antibodies to cyclic citrullinated peptide in patients with early arth 2007 Apr The objective of this study was to determine the diagnostic value for rheumatoid arthritis (RA) of antibodies to cyclic citrullinated peptides (anti-CCP) in patients with early arthritis and vasculitis. Sixty-four adult patients with early arthritis and disease duration of less than 4 months were clinically diagnosed by an experienced rheumatologist as having RA (n=27), spondyloarthropathy (n=11), and undifferentiated arthritis (n=26). Eighteen patients with vasculitis were also included in the study. The patients with early arthritis were followed up for 9 months. After the follow-up period, five of 26 patients with undifferentiated arthritis were diagnosed as having RA. All serum samples were tested for anti-CCP and IgM rheumatoid factor (IgM-RF). The anti-CCP positivity in RA patients (44.4%) was significantly more frequent than in patients with undifferentiated arthritis (3.8%), spondyloarthropathy (0%), and vasculitis (5.6%) (p=0.001, p<0.01, and p<0.01, respectively). The frequency of IgM-RF positivity was 40.7% in RA, 7.7% in undifferentiated arthritis, 0% in spondyloarthropathy, and 22.2% in vasculitis groups. The respective specificity of anti-CCP and IgM-RF tests for early RA were 97.3 and 94.6%, and the respective sensitivity of them were 44.4 and 40.7%, respectively. The combination of anti-CCP and IgM-RF positivity had a very high specificity and positive predictive value (100%) but a rather low sensitivity (33.3%). When either anti-CCP or IgM-RF positivity combined into one criterion, the sensitivity became high (51.9%) but the specificity decreased to 91.9%. Overall performance of anti-CCP test alone for the early RA was higher than IgM-RF and the combination of anti-CCP and IgM-RF (p<0.05), and was similar to the combination of anti-CCP or IgM-RF. The specificity of positive anti-CCP test for diagnosis of established RA reached up to 100%. In conclusion, the anti-CCP test is a new diagnostic test with extremely high specificity for RA. Anti-CCP antibody testing combined with IgM-RF testing has additional value over IgM-RF testing alone in patients with early arthritis.
16474032 Anti-cyclic citrullinated peptide antibodies in hepatitis C virus associated rheumatologic 2006 Mar OBJECTIVE: To investigate the diagnostic reliability of anti-CCP antibodies (anti-CCP Ab) in distinguishing hepatitis C virus (HCV) associated rheumatological manifestations and Sjögren's syndrome from rheumatoid arthritis. METHODS: 147 HCV infected patients (HCV RNA positive) were compared with 64 patients with definite rheumatoid arthritis in a retrospective study. Anti-CCP Ab were detected using the Immunoscan ELISA kit (second generation) and rheumatoid factor (RF) by the FIDIStrade mark Rheuma kit. RESULTS: Among the 147 HCV infected patients (77 women; mean (SD) age 58 (16) years), 77 (52%) had a mixed cryoglobulin (MC), 38 (26%) an MC associated systemic vasculitis, 35 (24%) arthralgia/arthritis, and seven (5%) definite Sjögren's syndrome. HCV infected patients with arthralgia were more often RF positive than those without arthralgia (54% v 27%; p = 0.003), but less often than patients with rheumatoid arthritis (54% v 81%; p = 0.009). Anti-CCP Ab were detected in only two HCV infected patients with arthralgia (5.7%), in none without arthralgia or with Sjögren's syndrome, and in 78% of patients with rheumatoid arthritis. With a specificity of 93.5% and a positive predictive value of 96% for rheumatoid arthritis, anti-CCP Ab were the most specific biological marker. CONCLUSIONS: Anti-CCP antibodies are very rarely found in HCV infected patients with rheumatological manifestations or Sjögren's syndrome. They are reliable serological markers to distinguish these from patients with rheumatoid arthritis.
17169563 Total knee arthroplasty effectiveness in patients 55 years old and younger: osteoarthritis 2007 Jan In the past, total knee arthroplasty, although very successful, was only indicated for an elderly population. Recently though, several papers have been published confirming that total knee arthroplasty is effective in younger patients. This paper supports the results of those papers. In our study, 207 total knee arthroplasties were performed on patients 55 years old and younger using a posterior cruciate-retaining prosthesis. There was an overall survival rate of 97.6% with an average follow-up of 9.1 years. There were some minor variations in the outcome of the operation based on diagnosis (osteoarthritis vs. rheumatoid arthritis). The success also continued over time with an estimated survival rate of 94.8% at 12 years. Total knee arthroplasty is an effective operation in patients younger then 55 years old.
17039306 Application of cellular gene therapy for rheumatoid arthritis. 2006 Rheumatoid arthritis (RA) is a common autoimmune disease characterized by persistent inflammation of joints resulting in progressive destruction of cartilage and bone. Recently, biological agents that suppress the activities of proinflammatory cytokines have shown efficacy as antirheumatic drugs, but require frequent administration, and often result in systemic immune suppression. Thus, gene transfer approaches are being developed as an alternative approach for targeted, more efficient, and sustained delivery of inhibitors of inflammatory cytokines as well as other therapeutic agents. Several gene therapy approaches have been established in preclinical animal models. In these models, autoantigen-specific T cells have been demonstrated to be ideal gene delivery vehicles for the local delivery of "immunoregulatory molecules" because these cells have tissue-specific homing and retention properties. Indeed, bioluminescence studies in an animal model of inflammatory arthritis revealed that these cells accumulated in and remained in inflamed joints. Transfer of genetically modified dendritic cells (DCs) may also have interesting effects. We conclude that modifying antigen-specific T cells or autologous DCs by retroviral transduction for local expression of regulatory proteins is a promising therapeutic strategy for the treatment of RA.
16971318 Abatacept: A review of a new biologic agent for refractory rheumatoid arthritis for dermat 2006 Abatacept is a newly approved treatment for rheumatoid arthritis refractory to other agents. Abatacept is a fusion protein of the cytotoxic T-lymphocyte antigen (CTLA) molecule and immunoglobulin (Ig) G1 that blocks CD28. Specifically, abatacept blocks the CD80 and CD86 ligands on the surface of antigen-presenting cells that must interface with the T-cell's CD28 receptor to activate T cells. Abatacept seems to be more immunosuppressive than tumor necrosis factor alpha blockers. The combination of abatacept and a tumor necrosis factor alpha blocking agent does not seem more effective than either agent alone. Because abatacept has the ability to suppress T-cell function, it has the potential to be a treatment for psoriasis and other autoimmune conditions involving pathologic processes driven by T cells.
16447242 Morphologic and quantitative assessment of CD20+ B cell infiltrates in rheumatoid arthriti 2006 Feb OBJECTIVE: B lymphocytes are emerging as important elements in the events leading to joint destruction in rheumatoid arthritis (RA). However, B lymphocytes have not been studied in rheumatoid arthritis (RA)-associated lung disease. We performed a morphologic and quantitative analysis of B lymphocytes and plasma cells in RA-associated interstitial pneumonia (IP) in comparison with idiopathic IP and normal lungs. METHODS: Open-lung biopsy specimens from patients with RA-associated IP (n = 18), patients with idiopathic IP (n = 21), and control subjects (n = 11) were stained with antibodies to CD20 and CD138. Morphologic patterns of stained specimens were characterized and staining was quantified using computer-assisted image analysis. RESULTS: In RA-associated IP, marked follicular B cell hyperplasia was detected, which was limited almost entirely to peribronchiolar lymphoid aggregates. Plasma cells were also present in large numbers, but showed a more diffuse tissue infiltration. Quantification of B cells demonstrated higher cellularity in RA-associated IP (median 2.0%, interquartile range [IQR] 1.0-5.7) as compared with idiopathic IP (0.9%, IQR 0.5-2.1). Control specimens showed a significantly smaller number of B cells compared with both diseases (0.4%, IQR 0.1-1.3). In RA patients who were smokers and in those who were male, the proportion of CD20+ tissue areas further increased to 4.3% (IQR 1.0-5.8) and 3.9% (IQR 0.7-6.9), respectively. CONCLUSION: We demonstrated a significant follicular B cell hyperplasia in RA-associated IP. The differences between RA-associated IP and idiopathic IP imply a differential emphasis of B cell-mediated mechanisms in the 2 diseases despite radiologic and histologic similarities and provide a rationale for studying functional aspects of B cell involvement in the pathogenesis of RA-associated IP.