Role of Anti-Carbamylated Protein Antibodies Compared to Anti-Citrullinated Protein Antibodies in Indigenous North Americans With Rheumatoid Arthritis, Their First-Degree Relatives, and Healthy Controls.

OBJECTIVE: Rheumatoid arthritis (RA) is characterized by the presence of autoantibodies, including seropositivity for rheumatoid factor (RF) and anti-citrullinated protein antibodies (ACPAs). In addition, antibodies to carbamylated proteins (anti-CarP) are present in patients with RA and are associated with joint damage. This study was undertaken to assess the presence of anti-CarP antibodies in indigenous North Americans (First Nations [FN] populations) with RA compared to their at-risk first-degree relatives (FDRs) and healthy controls. METHODS: Anti-CarP IgG and ACPAs (specifically, anti-cyclic citrullinated peptide [anti-CCP] antibodies) were measured by enzyme-linked immunosorbent assay in the sera of FN patients with RA (n = 95), their unaffected FDRs (n = 109), and healthy FN controls (n = 85). Antibodies to additional citrullinated peptides were measured using a multiplex ACPA array, and the number of peptides recognized was reported as an ACPA score. Groups were compared using the chi-square test and Mann-Whitney U test. Associations between RA and seropositivity for RF, ACPAs, and anti-CarP antibodies were determined by logistic regression. RESULTS: Anti-CarP antibodies were more frequent in FN patients with RA (44.3%) compared to FDRs (18.3%) and FN controls (4.7%) (both P < 0.0001 versus RA). Moreover, anti-CarP antibodies were more frequent in FDRs than in FN controls (P = 0.008). The ACPA score was higher in anti-CCP-positive FN patients with RA than in anti-CCP-positive FN FDRs (median score 7 [interquartile range (IQR) 7] versus median score 1 [IQR 4]; P = 0.04). The association with RA was strongest when all 3 autoantibodies (RF, anti-CCP, and anti-CarP) were present in the patients' serum (odds ratio 194, 95% confidence interval 23-1,609, P < 0.0001). CONCLUSION: Anti-CarP antibodies are prevalent in FN patients with RA and also more common in their at-risk FDRs compared to healthy controls. The results indicate an association of RF, ACPAs, and anti-CarP with RA that is strongest when all 3 autoantibodies are present. These findings may provide new insights into the evolution of autoimmunity in preclinical RA.

Avidity maturation of anti-citrullinated protein antibodies in rheumatoid arthritis.

OBJECTIVE: Anti-citrullinated protein antibodies (ACPAs) are highly specific for rheumatoid arthritis (RA) and are present years before the onset of symptoms. The avidity of autoantibodies can have a strong impact on their effector potency. This study was undertaken to analyze the avidity of ACPAs in serum samples obtained from ACPA-positive healthy individuals (predisease), patients with early disease, and patients with established RA as well as the avidity maturation over time in samples from healthy subjects who later developed RA. METHODS: We measured ACPA avidity in serum samples from ACPA-positive healthy individuals, symptomatic individuals, and patients with established RA in 5 collections from The Netherlands, Canada, and Austria. We determined the dynamics of avidity maturation of ACPAs from the predisease stage to established disease in 1 case from the native North American population and in 10 cases from a Dutch blood donor cohort. RESULTS: The overall ACPA response was characterized by low-avidity antibodies. Higher-avidity ACPAs were observed in symptomatic patients only, while low-avidity ACPAs were observed in both healthy subjects and patients. In longitudinal samples obtained from subjects prior to disease onset, ACPA avidity increased over time until disease onset. No further avidity maturation was observed after disease onset. CONCLUSION: Our findings indicate that avidity maturation of the ACPA response takes place prior to disease onset.

Non-HLA genes modulate the risk of rheumatoid arthritis associated with HLA-DRB1 in a susceptible North American Native population.

Most of the genetic risk for rheumatoid arthritis (RA) is conferred by 'shared epitope' (SE), encoding alleles of HLA-DRB1. Specific North American Native (NAN) populations have RA prevalence rates of 2-5%, representing some of the highest rates estimated worldwide. As many NAN populations also demonstrate a high background frequency of SE, we sought to determine whether other genetic factors contribute to disease risk in this predisposed population. RA patients (n=333) and controls (n=490) from the Cree/Ojibway NAN population in Central Canada were HLA-DRB1 typed and tested for 21 single-nucleotide polymorphisms (SNPs) that have previously been associated with RA, including PTPN22, TRAF1-C5, CTLA4, PADI4, STAT4, FCRL3, CCL21, MMEL1-TNFRSF14, CDK6, PRKCQ, KIF5A-PIP4K2C, IL2RB, TNFAIP3, IL10-1082G/A and REL. Our findings indicate that SE is prevalent and represents a major genetic risk factor for RA in this population (82% cases versus 68% controls, odds ratio=2.2, 95% confidence interval 1.6-3.1, P<0.001). We also demonstrate that in the presence of SE, the minor allele of MMEL1-TNFRSF14 significantly reduces RA risk in a dominant manner, whereas TRAF1-C5 increases the risk. These findings point to the importance of non-HLA genes in determining RA risk in a population with a high frequency of disease predisposing HLA-DRB1 alleles.

The immunology of ankylosing spondylitis and rheumatoid arthritis: a tale of similarities and dissimilarities.

Ankylosing spondylitis (AS) and rheumatoid arthritis (RA) are immune-mediated inflammatory joint diseases with the potential for significant target organ damage. Genetic factors play an important role in defining disease susceptibility. Both diseases are mediated in part by TNF, since anti-TNF therapies have proved effective in both AS and RA. Despite their similarities, the genetic elements associated with the respective diseases differ, most notably in HLA associations, with AS being associated with class I HLA alleles and RA associated with class II HLA alleles. AS has a predilection for axial joints whereas RA targets peripheral joints, but the immunological basis of that distinction is unknown. Autoantibody formation is the immunological hallmark of RA, whereas AS is notable for being a "seronegative" disease. Growing knowledge of new aspects of the host immune response (such as innate immune responses and Th17 cells) is adding to new insights into shared mechanisms of pathogenesis between these two diseases.

Multiplex serum cytokine monitoring as a prognostic tool in rheumatoid arthritis.

OBJECTIVE: Early optimized therapy of rheumatoid arthritis (RA) results in improved outcomes. The initiation of optimized therapy is hindered by the difficulty of early diagnosis and the limitations of current disease activity and therapeutic response assessment tools. Identifying patients requiring early combination DMARD/biologic therapy is currently a significant clinical challenge given the lack of definitive prognostic criteria. Since cytokines are soluble intracellular signaling molecules that modulate disease pathology in RA, we tested the recent conjecture that en mass serum cyto-kine measurement and monitoring will provide a useful tool for effective therapeutic management in RA. METHODS: We assayed the levels of 16 serum cytokines in 18 RA patients treated prospectively with methotrexate and from 18 unaffected controls. Specific mechanistic aspects of inflammatory pathology in the periphery could be discerned on a patient-specific basis from patients' serum cytokine profiles, information that may aid in the design of anti-cytokine biologic therapy. A serum Cytokine Activity Index (CAI) was also created using multi-variant analysis methods. RESULTS: Distinct cytokines were significantly elevated in RA patients relative to controls, and three distinct clusters with correlations to disease activity were identified. The Cytokine Activity Index correlated well with the therapeutic res-ponse; responders and non-responders in this cohort were distinguishable as early as one month post initiation of methotrexate therapy, well before clinical assessments of response are commonly completed. CONCLUSION: Clinical assessment tools could be derived from this approach that may provide a means to continually track patients, allowing intervention strategies to be better evaluated on a patient-specific basis and to identify residual cytokine activity that could be used to guide combination therapy.

Elevated levels of IgM and IgA antibodies to Proteus mirabilis and IgM antibodies to Escherichia coli are associated with early rheumatoid factor (RF)-positive rheumatoid arthritis.

OBJECTIVE: Antibodies to Proteus mirabilis were previously detected in patients with established rheumatoid arthritis (RA). We examined the prevalence of antibodies to P. mirabilis and their associations with RA in early synovitis patients. METHODS: Two hundred and forty-six patients with inflammatory arthritis for less than 1 yr were prospectively evaluated for 1 yr. Of these patients, 30% had rheumatoid factor (RF)-positive RA, 16% RF-negative RA, 17% a spondyloarthropathy and 37% undifferentiated arthritis. Serum antibodies to P. mirabilis, Escherichia coli and other potentially arthritogenic organisms (Chlamydia, Salmonella, Shigella, Campylobacter, Yersinia and parvovirus B19) and for antibodies specific for immunoglobulin (Ig) G damaged with advanced glycation end-products (anti-IgG-AGE) were measured. RESULTS: IgM and IgA anti-Proteus antibodies were significantly higher in patients with RF-positive RA compared with all other patient groups (P < 0.0005 and P < 0.005). Anti-P. mirabilis IgG, and IgG, IgA, and IgM antibodies to other potentially arthritogenic pathogens did not differ in the patient groups. IgM antibodies to E. coli were elevated in RF-positive RA patients. Anti-P. mirabilis IgM and IgA results were not explained by false-positive reactions, because after absorption of RF there was no decrease in antibodies to Proteus in 10 of 12 patients. Proteus and E. coli antibodies were highest in patients positive for both RF and anti-IgG-AGE antibodies (P<0.001). Patients with erosions tended to have higher IgA anti-Proteus titres, but no association with the shared HLA epitope or treatment was detected. CONCLUSION: Anti-P. mirabilis IgM and IgA and anti-E. coli IgM antibody elevations are associated with early seropositive RA and the presence of anti-IgG-AGE antibodies. The role that P. mirabilis or E. coli plays in early RF-positive RA requires further investigation.

Raised granzyme B levels are associated with erosions in patients with early rheumatoid factor positive rheumatoid arthritis.

BACKGROUND: Raised granzyme B in serum and synovium of patients with rheumatoid arthritis suggests a role for cytotoxic T cells and natural killer cells in the pathogenesis of this disease. OBJECTIVE: To evaluate serum granzyme B in patients with early arthritis and correlate it with specific diagnosis and clinical indices of disease severity. METHODS: 257 patients with inflammatory arthritis for less than one year (46% rheumatoid arthritis, 17% spondyloarthropathy, 37% undifferentiated arthritis) had a prospective clinical, serological, and radiographic evaluation. Granzyme B was measured in initial sera by ELISA. Patients were HLA typed for DR alleles using sequence specific primers. A logistic regression model was used to evaluate the potential prognostic value of serum granzyme B in predicting radiographic erosions after one year of follow up. RESULTS: Granzyme B values were similar in rheumatoid arthritis, spondyloarthropathy, and undifferentiated arthritis. Concentrations were higher in rheumatoid factor (RF) positive patients than in RF negative patients (mean (SD): 3.15 (0.92) v 2.89 (0.71) pg/ml; p<0.05). After one year, erosions were present in 30% of patients in the overall cohort, and in 44% of patients with rheumatoid arthritis. In the entire cohort, serum granzyme B did not predict erosions independently. However, high granzyme B was an independent predictor of early erosions in patients with RF positive rheumatoid arthritis (odds ratio = 4.83 (95% confidence interval, 1.13 to 20.59)) (p<0.05). CONCLUSIONS: Granzyme B may be a useful prognostic marker in early rheumatoid arthritis and may provide important clues to the pathogenesis of this disease.

Infrared spectroscopy: shedding light on synovitis in patients with rheumatoid arthritis.

OBJECTIVES: It is difficult to determine the extent of synovial involvement early in the course of rheumatoid arthritis. A spectroscopic technique was used to characterize the synovium of the small finger joints in both early and late rheumatoid arthritis. This synovium was also compared against normal joints. METHODS: Near-infrared spectroscopy assesses the absorption of near-infrared light by specific joints, giving a characteristic "fingerprint" of the properties of the underlying tissues. Triple measurements by infrared spectroscopy were taken at the bilateral second and third metacarpophalangeal joints. Multivariate analysis was applied. RESULTS: Analysis was able to demonstrate relationships between the specific sources of spectral variation and joint tenderness or swelling as well as radiographic damage. Further use of multivariate analysis allowed recognition of the spectral patterns seen in early disease vs late rheumatoid arthritis and correct classification of over 74% of the joints. CONCLUSIONS: The spectral regions where differences occurred were in the absorption bands related to tissue oxygenation status, allowing the provocative implication that this technique could be detecting ischaemic changes within the joint. Near-infrared spectroscopy may thus be able to provide us with some information about the biochemical changes associated with synovitis.

The histopathology of early synovitis.

Early diagnosis and therapeutic intervention are needed to prevent the morbidity related to erosive arthropathies such as rheumatoid arthritis (RA), yet it is difficult to distinguish various forms of synovitis early in the disease course. The availability of synovial tissue biopsy techniques has facilitated the analysis of synovial tissue from patients with early disease. Comparison of the histopathologic features of synovial tissue in early RA, established RA, and in non-RA synovitis has shown subtle, but potentially important differences in histologic features, cytokine and protease expression patterns, and apoptosis. Ultimately, it remains to be shown definitively that analysis of the histopathological features of synovial tissue early in disease is of independent value in identifying patients destined to have persistent synovitis or erosive disease, and in turn, in allocating patients to specific therapeutic strategies.

Active synovial matrix metalloproteinase-2 is associated with radiographic erosions in patients with early synovitis.

INTRODUCTION: In cancer the gelatinases [matrix metalloproteinase (MMP)-2 and MMP-9] have been shown to be associated with tissue invasion and metastatic disease. In patients with inflammatory arthritis the gelatinases are expressed in the synovial membrane, and have been implicated in synovial tissue invasion into adjacent cartilage and bone. It is hypothesized that an imbalance between the activators and inhibitors of the gelatinases results in higher levels of activity, enhanced local proteolysis, and bone erosion. OBJECTIVES: To determine whether the expression and activity levels of MMP-2 and MMP-9, and their regulators MMP-14 and tissue inhibitor of metalloproteinase (TIMP), are associated with early erosion formation in patients with synovitis of recent onset. PATIENTS AND METHOD: A subset of 66 patients was selected from a larger early synovitis cohort on the basis of tissue availability for the study of synovial tissue and serum gelatinase expression. Patients with peripheral joint synovitis of less than 1 years' duration were evaluated clinically and serologically on four visits over a period of 12 months. At the initial visit, patients underwent a synovial tissue biopsy of one swollen joint, and patients had radiographic evaluation of hands and feet initially and at 1year. Serum MMP-1, MMP-2, MMP-9, MMP-14, and TIMP-1 and TIMP-2 levels were determined, and synovial tissue was examined by immunohistology for the expression of MMP-2 and MMP-9, and their molecular regulators. Gelatinolytic activity for MMP-2 and MMP-9 was quantified using a sensitive, tissue-based gel zymography technique. Four healthy individuals underwent closed synovial biopsy and their synovial tissues were similarly analyzed. RESULTS: Of the 66 patients studied, 45 fulfilled American College of Rheumatology criteria for rheumatoid arthritis (RA), with 32 (71%) being rheumatoid factor positive. Of the 21 non-RA patients, seven had a spondylarthropathy and 14 had undifferentiated arthritis. Radiographically, 12 of the RA patients had erosions at multiple sites by 1 year, whereas none of the non-RA patients had developed erosive disease of this extent. In the tissue, latent MMP-2 was widely expressed in the synovial lining layer and in areas of stromal proliferation in the sublining layer and stroma, whereas MMP-9 was expressed more sparsely and focally. MMP-14, TIMP-2, and MMP-2 were all detected in similar areas of the lining layer on consecutive histologic sections. Tissue expression of MMP-14, the activator for pro-MMP-2, was significantly higher in RA than in non-RA patients (8.4 +/- 5 versus 3.7 +/- 4 cells/high-power field; P = 0.009). In contrast, the expression of TIMP-2, an inhibitor of MMP-2, was lower in the RA than in the non-RA samples (25 +/- 12 versus 39 +/- 9 cells/high-power field; P = 0.01). Synovial tissue expressions of MMP-2, MMP-14, and TIMP-2 were virtually undetectable in normal synovial tissue samples. The synovial tissue samples of patients with erosive disease had significantly higher levels of active MMP-2 than did those of patients without erosions (Fig. 1). Tissue expression of MMP-2 and MMP-9, however, did not correlate with the serum levels of these enzymes. With the exception of serum MMP-2, which was not elevated over normal, serum levels of all of the other MMPs and TIMPs were elevated to varying degrees, and were not predictive of erosive disease. Interestingly, MMP-1 and C-reactive protein, both of which were associated with the presence of erosions, were positively correlated with each other (r = 0.42; P < 0.001). DISCUSSION: MMP-2 and MMP-9 are thought to play an important role in the evolution of joint erosions in patients with an inflammatory arthritis. Most studies have concentrated on the contribution of MMP-9 to the synovitis, because synovial fluid and serum MMP-9 levels are markedly increased in inflammatory arthropathies. Previously reported serum levels of MMP-9 have varied widely. In the present sample of patients with synovitis of recent onset, serum MMP-9 levels were elevated in only 21%. Moreover, these elevations were not specific for RA, the tissue expression of MMP-9 was focal, and the levels of MMP-9 activity were not well correlated with early erosions. Although serum MMP-2 levels were not of prognostic value, high synovial tissue levels of MMP-2 activity were significantly correlated with the presence of early erosions. This may reflect augmented activation of MMP-2 by the relatively high levels of MMP-14 and low levels of TIMP-2 seen in these tissues. We were able to localize the components of this trimolecular complex to the synovial lining layer in consecutive tissue sections, a finding that is consistent with their colocalization. In conclusion, we have provided evidence that active MMP-2 complexes are detectable in the inflamed RA synovium and may be involved in the development of early bony erosions. These results suggest that strategies to inhibit the activation of MMP-2 may have the potential for retarding or preventing early erosions in patients with inflammatory arthritis.

Rheumatoid arthritis associated autoantibodies in patients with synovitis of recent onset.

STATEMENT OF FINDINGS: An inception cohort of 238 patients having peripheral joint synovitis of less than 12 months duration was evaluated clinically and followed prospectively for 1 year to determine the clinical significance of a number of rheumatoid arthritis (RA) associated autoantibodies. Serum samples collected at the time of the initial evaluation were tested for rheumatoid factor (RF) and antibodies to Sa (anti-Sa), RA-33, (pro)filaggrin [antifilaggrin antibody (AFA)], cyclic citrullinated peptide (anti-CCP), calpastatin, and keratin [antikeratin antibody (AKA)]. RF had a sensitivity of 66% and a specificity of 87% for RA. Anti-Sa, AFA, and anti-CCP all had a specificity of more than 90%, but a sensitivity of less than 50% for this diagnosis. Overall, there was a high degree of correlation between AFA, AKA, anti-Sa or anti-CCP, this being highest between anti-Sa and anti-CCP (odds ratio, 13.3; P < 0.001). Of the 101 patients who were positive for at least one of these four autoantibodies, 57% were positive for only one. Finally, anti-SA identified a subset of predominantly male RA patients with severe, erosive disease. Anti-SA, AFA and anti-CCP are all specific for early RA but, overall, have little additional diagnostic value over RF alone. Although these antibodies may preferentially recognize citrullinated antigens, the modest degree of concordance between them in individual patient sera suggests that it is unlikely a single antigen is involved in generating these responses.

Evaluating patients with arthritis of recent onset: studies in pathogenesis and prognosis.

Inflammatory synovitis of recent onset poses a diagnostic and prognostic challenge to primary care physicians and rheumatologists. A lack of understanding of the underlying etiologic and pathogenic processes limits the ability to distinguish forms of arthritis that follow a benign, self-limiting course from forms that proceed to an aggressive, erosive disease requiring intensive immunosuppressive therapy. It is estimated that between 30% and 40% of patients presenting with early synovitis have disease that remains unclassified. Using data from a cohort of patients with early synovitis and reviewing current literature, we discuss investigational approaches toward a new classification of patients with early synovitis. Although a lack of understanding of this heterogeneous clinical syndrome has led clinicians to take a largely empirical approach to treatment thus far, the evolving awareness of disease predisposition at a genetic level and the expanding ability to specifically manipulate biological pathways may ultimately change the approach to this clinical problem. JAMA. 2000;284:2368-2373.

Stromal cell-derived factor-1-CXC chemokine receptor 4 interactions play a central role in CD4+ T cell accumulation in rheumatoid arthritis synovium.

Rheumatoid arthritis (RA) is characterized by the accumulation of CD4(+) memory T cells in the inflamed synovium. To address the mechanism, we analyzed chemokine receptor expression and found that the frequency of CXC chemokine receptor (CXCR)4 expressing synovial tissue CD4(+) memory T cells was significantly elevated. CXCR4 expression could be enhanced by IL-15, whereas stromal cell-derived factor (SDF)-1, the ligand of CXCR4, was expressed in the RA synovium and could be increased by CD40 stimulation. SDF-1 stimulated migration of rheumatoid synovial T cells and also inhibited activation-induced apoptosis of T cells. These results indicate that SDF-1-CXCR4 interactions play important roles in CD4(+) memory T cell accumulation in the RA synovium, and emphasize the role of stromal cells in regulating rheumatoid inflammation.

Association of HLA alleles and clinical features in patients with synovitis of recent onset.

OBJECTIVE: To determine how HLA alleles are associated with the clinical disease patterns of patients with synovitis of recent onset. METHODS: The HLA alleles A, B, C, DRbeta1, and DQbeta1 were determined in a cohort of 211 patients (mean age 42 years, 64% female, 79% white) with recent-onset synovitis in 1 or more peripheral joints. At a mean disease duration of 33 weeks, 98 patients (46%) met the American College of Rheumatology (ACR) criteria for rheumatoid arthritis (RA), 38 (18%) met the European Spondylarthropathy Study Group criteria for spondylarthropathy (SpA), and 75 (36%) were classified as having undifferentiated arthropathy (UA). Controls were racially matched healthy individuals (n = 244). RESULTS: Shared epitope (SE) alleles were significantly more common in rheumatoid factor-positive (RF+) patients fulfilling the ACR RA criteria than in other patients with early arthritis (65% versus 35%; P < 0.001). In addition, the RA patients had by far the highest frequency of radiographic erosions (52% and 39% in RF+ and RF- RA, respectively, versus 3% and 9% in SpA and UA patients, respectively; P < 0.0001). The presence of SE alleles was a particularly strong predictor of early erosions in the RF- RA patients (odds ratio [OR] 6.8, 95% confidence interval [95% CI] 1.2-45). The presence of 2 SE alleles or an associated DQbeta1*0301 (DQ7) or DQbeta1*0302 (DQ8) allele appeared to modestly increase the risk of early erosions, although these DQ alleles were in strong linkage disequilibrium with DRbeta1*0401, both in the patient and in the control populations. B27 was linked with the presence of SE alleles in the patients, including those patients fulfilling the RA criteria, but not in the controls (12% versus 3%; P < 0.001). Enthesitis was present in 23 (11%) of 211 patients, was highly associated with B27 (OR 4.2, 95% CI 1.5-11.5), and surprisingly, was not a feature specific only to the SpA group. The B8-DR3 haplotype was significantly increased in the patient subgroups compared with controls (17% versus 7%; P < 0.01), although the clinical significance of this association is unclear. CONCLUSION: This study of HLA associations in a diverse cohort of early synovitis patients emphasizes the complex degree of genetic interaction between alleles at several major histocompatibility complex loci, which regulates clinical phenotypes. In particular, SE and B27, while predisposing patients to characteristic clinical syndromes, had an unexpected degree of association in this cohort, perhaps explaining the overlap in clinical features in many patients.

Anti-inflammatory therapy.

The inflammatory response involves a complex set of stereotyped biochemical and cellular reactions that aim to eliminate pathogens. Systemic inflammatory disorders, such as rheumatoid arthritis and systemic lupus erythematosus, feature a persistent, uncontrolled inflammatory response that typically culminates in tissue damage. The control of this inflammatory response is of paramount importance in preventing irreversible tissue damage, as well as in controlling symptoms. NSAIDs and corticosteroids are the most effective agents currently available to control the clinical manifestations of inflammation, although they usually need to be used in conjunction with other "disease modifying" strategies in order to achieve optimum control of chronic inflammatory disorders. As with all pharmacologic therapy, the risk to benefit ratio of each agent needs to be considered carefully before embarking on extended courses of therapy. Strategies to minimize the long-term risks of NSAIDs and corticosteroids are continuing to evolve and hold the promise of greater safety without loss of efficacy.

HLA associations of seropositive rheumatoid arthritis in a Cree and Ojibway population.

OBJECTIVE: To determine the HLA associations of seropositive rheumatoid arthritis (RA) in a Cree and Ojibway population; to determine whether specific alleles distinguish juvenile or adult onset. METHODS: HLA-A, B, C, and DRB1 alleles were analyzed in 23 Ojibway and Cree patients with RA seen in a single tertiary care center. Comparisons were made with published results of controls and with results of 18 patients with rheumatoid factor (RF) positive polyarticular juvenile rheumatoid arthritis (JRA) from the same population. RESULTS: Comparisons among patients with RA, patients with RF positive polyarticular JRA, and controls showed increased frequencies of the RA shared epitope in patients with RA and of DRB1*0901 in patients with seropositive polyarticular JRA, while the frequency of DRB1*08 alleles was decreased in patients with RF positive polyarticular JRA. CONCLUSION: In this population, DRB1*0901 may promote while DRB1*08 alleles may protect against a juvenile onset of RA specifically. In contrast, the RA shared epitope may have a greater effect on the risk of adult onset seropositive RA. Due to the small patient numbers, these results require confirmation.

Digital necrosis as a paraneoplastic syndrome.

We describe a 62-year-old woman who developed sudden onset of digital ulceration and necrosis with high titres of antinuclear antibodies and cutaneous vasculitis who was found to have small cell lung cancer. The combination of antinuclear antibodies, vasculitis, and digital ulceration has not been previously described in association with malignancy, although malignancy has been reported with each of these findings independently. The literature on digital necrosis as a paraneoplastic syndrome is reviewed and possible mechanisms discussed. This case is typical of the majority of those reported, in that the digital necrosis preceded the diagnosis of the malignancy, only the upper extremities were involved, the underlying malignancy was a carcinoma, and while treatment directed at the vasculitis was ineffective, there was rapid improvement of the digital lesions with treatment of the lung tumor. The most likely mechanism for these findings is a systemic vasculitis related to undefined tumor antigens. Unexplained digital necrosis should prompt a search for malignancy.

The differential expression of a novel intestinal epithelial glycoprotein in various forms of inflammatory bowel disease.

A13D8 is a monoclonal IgM antibody that identifies an as yet unknown antigen that is expressed intensely and ubiquitously in enterocytes. Immunohistochemically, it was shown that A13D8 has a granular supranuclear staining pattern in columnar epithelial cells of normal small intestine and the colon. In ulcerative colitis, this staining pattern was retained. However, during active inflammation, staining also was evident in goblet cells. To test whether this feature of goblet cell staining was unique to ulcerative colitis, tissue sections from a variety of colitides were examined. Crohn's disease, infectious colitis, and ischemic colitis had similar staining patterns to that seen with ulcerative colitis. There was significantly more inflammation in the biopsies from patients with ulcerative colitis and Crohn's disease with positive goblet cell staining than in the biopsies from those patients with negative goblet cell staining. Almost all positive goblet cell staining in ulcerative colitis and Crohn's disease occurred in biopsies that were actively inflamed, whereas there was rare staining in biopsies that were noninflamed (regardless of whether or not there was active inflammation elsewhere in the colon). Ileal goblet cells stained positively with A13D8 only in cases of active ileitis. In cases of collagenous colitis, with comparable degrees of inflammation to that seen in ulcerative colitis and Crohn's disease, there was rarely goblet cell staining and in graft-versus-host disease goblet cell staining of A13D8 was not observed. The binding of A13D8 to tissue sections was completely inhibited by N-acetyl-D-galactosamine. These results, in conjunction with immunochemical studies, suggest that the antibody recognizes an N-acetyl-D galactosamine-containing epitope on a glycoprotein(s). In conclusion, these data suggest that A13D8 recognizes a glycoprotein expressed by intestinal columnar epithelial cells and during specific inflammatory states, particularly those associated with a neutrophilic infiltrate, becomes evident in goblet cells. Further work is required to establish the exact nature of this molecule and whether it is a pro- or anti-inflammatory factor.

Immunohistologic study of T-cell receptor delta-chain expression in rheumatoid synovial membranes.

Lymphocytes expressing gamma delta T-cell receptors (TCRs) have been shown to be reactive to mycobacterial antigens as well as the so-called stress proteins. The detection of increased numbers of gamma delta cells in the synovial fluid and peripheral blood of some patients with rheumatoid arthritis has suggested a potential role for these lymphocytes in the pathogenesis of this disorder. Twenty-three rheumatoid synovial membranes were studied using immunohistology and monoclonal antibodies in an attempt to define the patterns of distribution of gamma delta T cells in rheumatoid synovitis. Consecutive sections were stained for T1(CD5), T4(CD4), T8(CD8), TAC(CD25), the delta-chain markers delta TCR1 and delta TCS1, and the beta-chain marker beta F1. Our results show some regional differences in the distribution of CD4 and CD8 cells, the former being prominent in the lymphocytic aggregates and the latter most prominent in diffuse infiltrates immediately adjacent to the synovial lining layer. All tissues showed extensive staining for beta F1; an estimated average of more than 90% of T cells expressed alpha beta TCR. The majority of samples showed limited staining for both delta-chain antibodies, with 20 of the 23 tissues appearing to have less than 1% of T lymphocytes expressing these markers. Three tissues stained extensively for both delta TCR1 and delta TCS1 in particular areas of the section. In these areas, small perivascular lymphocytic aggregates appeared to be composed mainly of gamma delta cells. TAC staining was virtually absent in all areas and tissues. It was concluded that the majority of T lymphocytes infiltrating rheumatoid synovial membranes express alpha beta TCR.(ABSTRACT TRUNCATED AT 250 WORDS)