An African ancestry-specific allele of CTLA4 confers protection against rheumatoid arthritis in African Americans.

Cytotoxic T-lymphocyte associated protein 4 (CTLA4) is a negative regulator of T-cell proliferation. Polymorphisms in CTLA4 have been inconsistently associated with susceptibility to rheumatoid arthritis (RA) in populations of European ancestry but have not been examined in African Americans. The prevalence of RA in most populations of European and Asian ancestry is approximately 1.0%; RA is purportedly less common in black Africans, with little known about its prevalence in African Americans. We sought to determine if CTLA4 polymorphisms are associated with RA in African Americans. We performed a 2-stage analysis of 12 haplotype tagging single nucleotide polymorphisms (SNPs) across CTLA4 in a total of 505 African American RA patients and 712 African American controls using Illumina and TaqMan platforms. The minor allele (G) of the rs231778 SNP was 0.054 in RA patients, compared to 0.209 in controls (4.462 x 10(-26), Fisher's exact). The presence of the G allele was associated with a substantially reduced odds ratio (OR) of having RA (AG+GG genotypes vs. AA genotype, OR 0.19, 95% CI: 0.13-0.26, p = 2.4 x 10(-28), Fisher's exact), suggesting a protective effect. This SNP is polymorphic in the African population (minor allele frequency [MAF] 0.09 in the Yoruba population), but is very rare in other groups (MAF = 0.002 in 530 Caucasians genotyped for this study). Markers associated with RA in populations of European ancestry (rs3087243 [+60C/T] and rs231775 [+49A/G]) were not replicated in African Americans. We found no confounding of association for rs231778 after stratifying for the HLA-DRB1 shared epitope, presence of anti-cyclic citrullinated peptide antibody, or degree of admixture from the European population. An African ancestry-specific genetic variant of CTLA4 appears to be associated with protection from RA in African Americans. This finding may explain, in part, the relatively low prevalence of RA in black African populations.

Most common single-nucleotide polymorphisms associated with rheumatoid arthritis in persons of European ancestry confer risk of rheumatoid arthritis in African Americans.

OBJECTIVE: Large-scale genetic association studies have identified >20 rheumatoid arthritis (RA) risk alleles among individuals of European ancestry. The influence of these risk alleles has not been comprehensively studied in African Americans. We therefore sought to examine whether these validated RA risk alleles are associated with RA risk in an African American population. METHODS: Twenty-seven candidate single-nucleotide polymorphisms (SNPs) were genotyped in 556 autoantibody-positive African Americans with RA and 791 healthy African American control subjects. Odds ratios (ORs) and 95% confidence intervals (95% CIs) for each SNP were compared with previously published ORs for RA patients of European ancestry. We then calculated a composite genetic risk score (GRS) for each individual based on the sum of all risk alleles. RESULTS: Overlap of the ORs and 95% CIs between the European and African American populations was observed for 24 of the 27 candidate SNPs. Conversely, 3 of the 27 SNPs (CCR6 rs3093023, TAGAP rs394581, and TNFAIP3 rs6920220) demonstrated ORs in the opposite direction from those reported for RA patients of European ancestry. The GRS analysis indicated a small but highly significant probability that African American patients relative to control subjects were enriched for the risk alleles validated in European RA patients (P = 0.00005). CONCLUSION: The majority of RA risk alleles previously validated for RA patients of European ancestry showed similar ORs in our population of African Americans with RA. Furthermore, the aggregate GRS supports the hypothesis that these SNPs are risk alleles for RA in the African American population. Future large-scale genetic studies are needed to validate these risk alleles and identify novel RA risk alleles in African Americans.

New insights into the pathogenesis and genetics of psoriatic arthritis.

Psoriasis vulgaris and psoriatic arthritis (PsA) are inter-related heritable diseases. Psoriatic skin is characterized by hyperproliferative, poorly differentiated keratinocytes and severe inflammation. Psoriatic joints are characterized by highly inflamed synovia and entheses with focal erosions of cartilage and bone. Genetic analyses have uncovered risk factors shared by both psoriasis and PsA. Predisposition to psoriasis and PsA arising from common variation is most strongly conferred by the HLA class I region. Other genetic risk factors implicate the interleukin (IL)-23 pathway and the induction and regulation of type 17 T-helper cells in the pathogenesis of both diseases. Secretion of cytokines, such as IL-22 and IL-17, could result in the hyperproliferative phenotype of keratinocytes and potentially synoviocytes, leading to a vicious cycle of cellular proliferation and inflammation in both the skin and joints. In synovial tissue, disease-related cytokines could also promote osteoclast formation, resulting in bone erosion. The next step will be to identify genetic risk factors specifically associated with PsA. Although therapies that target tumor necrosis factor are often highly successful in the treatment of both diseases, genetic findings are likely to lead to the development of treatments tailored to an individual's genetic profile.

Cardiovascular disease in rheumatoid arthritis.

RA can manifest in a variety of cardiac complications, including pericarditis, valvular disease, cardiomyopathy, and amyloidosis. Subclinical involvement is higher than anticipated. CVD is also prevalent in patients with RA, with onset in early disease. Several disease-specific risk factors, like seropositivity, disease activity, and medications, are implicated in the pathogenesis of CVD in RA. Cardiovascular risk assessment in RA varies from the general population. Some traditional risk factors like BMI and lipid levels apply differently to the RA population. Statins are useful in managing dyslipidemia in RA. There is good evidence to support cardiovascular risk reduction with methotrexate and TNF-I use if good disease control is achieved.

Complementary and alternative medicine use in African Americans with rheumatoid arthritis.

OBJECTIVE: Racial/ethnic differences with regard to complementary and alternative medicine (CAM) use have been reported in the US. However, specific details of CAM use by African Americans with rheumatoid arthritis (RA) are lacking. METHODS: Data were collected from African Americans with RA enrolled in a multicenter registry regarding the use of CAM, including food supplements, topical applications, activities, and alternative care providers. Factors associated with CAM use by sex and disease duration were assessed using t-test, Wilcoxon's rank sum test, chi-square test, and logistic regression analyses. RESULTS: Of the 855 participants, 85% were women and mean age at enrollment was 54 years. Overall, ever using any of the CAM treatments, activities, and providers was 95%, 98%, and 51%, respectively (median of 3 for number of treatments, median of 5 for activities, and median of 1 for providers). Those with longer disease duration (>2 years) were significantly more likely (odds ratio ≥2.0, P < 0.05) to use raisins soaked in vodka/gin, to take fish oils, or to drink alcoholic beverages for RA treatment than those with early disease. As compared to men, women were significantly (P < 0.05) more likely to pray/attend church, write in a journal, and use biofeedback, but were less likely to smoke tobacco or topically apply household oils for treatment of RA. CONCLUSION: CAM use was highly prevalent in this cohort, even in individuals with early disease. Health care providers need to be aware of CAM use as some treatments may potentially have interactions with conventional medicines. This could be important within this cohort of African Americans, where racial disparities are known to affect access to conventional care.

Comparison of the disease activity score using erythrocyte sedimentation rate and C-reactive protein in African Americans with rheumatoid arthritis.

OBJECTIVE: The Disease Activity Score based on 28 joints (DAS28) has been increasingly used in clinical practice and research studies of rheumatoid arthritis (RA). Studies have reported discordance between DAS28 based on erythrocyte sedimentation rate (ESR) versus C-reactive protein (CRP) in patients with RA. However, such comparison is lacking in African Americans with RA. METHODS: This analysis included participants from the Consortium for the Longitudinal Evaluation of African Americans with Early Rheumatoid Arthritis (CLEAR) registry, which enrolls self-declared African Americans with RA. Using tender and swollen joint counts, separate ESR-based and CRP-based DAS28 scores (DAS28-ESR3 and DAS28-CRP3) were calculated, as were DAS28-ESR4 and DAS28-CRP4, which included the patient's assessment of disease activity. The scores were compared using paired t-test, simple agreement and κ, correlation coefficient, and Bland-Altman plots. RESULTS: Of the 233 included participants, 85% were women, mean age at enrollment was 52.6 years, and median disease duration at enrollment was 21 months. Mean DAS28-ESR3 was significantly higher than DAS28-CRP3 (4.8 vs 3.9; p < 0.001). Similarly, mean DAS28-ESR4 was significantly higher than DAS28-CRP4 (4.7 vs 3.9; p < 0.001). ESR-based DAS28 remained higher than CRP-based DAS28 even when stratified by age, sex, and disease duration. Overall agreement was not high between DAS28-ESR3 and DAS28-CRP3 (50%) or between DAS28-ESR4 and DAS28-CRP4 (59%). DAS28-CRP3 underestimated disease activity in 47% of the participants relative to DAS28-ESR3 and DAS28-CRP4 in 40% of the participants relative to DAS28-ESR4. CONCLUSION: There was significant discordance between the ESR-based and CRP-based DAS28, a situation that could affect clinical treatment decisions for African Americans with RA.

Association of IL4R single-nucleotide polymorphisms with rheumatoid nodules in African Americans with rheumatoid arthritis.

INTRODUCTION: To determine whether IL4R single-nucleotide polymorphisms (SNPs) rs1805010 (I50V) and rs1801275 (Q551R), which have been associated with disease severity in rheumatoid arthritis (RA) patients of European ancestry, relate to the presence of rheumatoid nodules and radiographic erosions in African Americans. METHODS: Two IL4R SNPs, rs1805010 and rs1801275, were genotyped in 749 patients from the Consortium for Longitudinal Evaluation of African-Americans with Early Rheumatoid Arthritis (CLEAR) registries. End points were rheumatoid nodules defined as present either by physical examination or by chest radiography and radiographic erosions (radiographs of hands/wrists and feet were scored using the modified Sharp/van der Heijde system). Statistical analyses were performed by using logistic regression modeling adjusted for confounding factors. RESULTS: Of the 749 patients with RA, 156 (20.8%) had rheumatoid nodules, with a mean age of 47.0 years, 84.6% female gender, and median disease duration of 1.9 years. Of the 461 patients with available radiographic data, 185 (40.1%) had erosions (score>0); their mean age was 46.7 years; 83.3% were women; and median disease duration was 1.5 years. Patients positive for HLA-DRB1 shared epitope (SE) and autoantibodies (rheumatoid factor (RF) or anti-cyclic citrullinated peptide (CCP)) had a higher risk of developing rheumatoid nodules in the presence of the AA and AG alleles of rs1801275 (odds ratio (OR)adj=8.08 (95% confidence interval (CI): 1.60-40.89), P=0.01 and ORadj=2.97 (95% CI, 1.08 to 8.17), P=0.04, respectively). Likewise, patients positive for the HLA-DRB1 SE and RF alone had a higher risk of developing rheumatoid nodules in presence of the AA and AG alleles of rs1801275 (ORadj=8.45 (95% CI, 1.57 to 45.44), P=0.01, and ORadj=3.57 (95% CI, 1.18 to 10.76), P=0.02, respectively) and in the presence of AA allele of rs1805010 (ORadj=4.52 (95% CI, 1.20 to 17.03), P=0.03). No significant association was found between IL4R and radiographic erosions or disease susceptibility, although our statistical power was limited by relatively small numbers of cases and controls. CONCLUSIONS: We found that IL4R SNPs, rs1801275 and rs1805010, are associated with rheumatoid nodules in autoantibody-positive African-American RA patients with at least one HLA-DRB1 allele encoding the SE. These findings highlight the need for analysis of genetic factors associated with clinical RA phenotypes in different racial/ethnic populations.

Cutaneous manifestations of vasculitis.

OBJECTIVES: To discuss the clinical features, diagnostic evaluation, and treatment options for cutaneous vasculitis. METHODS: The literature in the PubMed database was reviewed regarding the presentation, pathophysiology, clinical workup, and treatment of cutaneous vasculitis. RESULTS: Available classification criteria of vasculitis are based on histopathologic criteria or clinicohistologic features. These have been designed more for research purposes than for clinical application. Skin findings such as palpable purpura, nodules, urticaria, ulcers, and infarction are clues to the presence of vasculitis. Pathologic findings of fibrinoid necrosis, infiltration by neutrophils or lymphocytes, and deposition of complement and immunoglobulin may be helpful in reaching a specific diagnosis. However, there is considerable overlap across different conditions. CONCLUSIONS: The correct diagnosis of cutaneous manifestations of vasculitis requires an understanding of vasculitis classification, recognition of specific clinical patterns, and the ability to interpret histopathologic data.

Anti-tumor necrosis factor therapy in patients with difficult to treat Takayasu arteritis.

OBJECTIVE: Granulomatous inflammation is a typical feature of Takayasu arteritis (TA), and tumor necrosis factor (TNF) is important in the formation of granulomas. In this study, we assessed therapy with anti-TNF agents in patients with TA that was not controlled by glucocorticoid therapy or other immunosuppressants. METHODS: We conducted an open-label trial of anti-TNF therapy at 3 academic medical centers over a period of 4.25 years. Fifteen patients with active, relapsing TA (median 6 years) were selected. Seven received etanercept (later changed to infliximab in 3 patients), and 8 received infliximab. Relapses had occurred in all patients while they were receiving glucocorticoids and, in 13 patients, additional immunosuppressive drugs. No other agents were added to the treatment regimen concurrently with anti-TNF. If patients were receiving cytotoxic agents, the dosage was not increased. Clinical symptoms were recorded, and physical examinations, laboratory studies, and serial magnetic resonance imaging were performed. RESULTS: The median daily dose of prednisone required to maintain remission prior to anti-TNF therapy was 20 mg. Ten of the 15 patients achieved complete remission that was sustained for 1-3.3 years without glucocorticoid therapy. Four patients achieved partial remission, with a >50% reduction in the glucocorticoid requirement. At a median of 12 months of followup, the median dose of prednisone was 0. Therapy failed in 1 patient. In 9 of the 14 responders, an increase in the anti-TNF dosage was required to sustain remission. Two relapses occurred during periods when anti-TNF therapy (etanercept) was interrupted, but remission was reestablished upon reinstitution of therapy. CONCLUSION: In this pilot study of relapsing TA, addition of anti-TNF therapy resulted in improvement in 14 of 15 patients and sustained remission in 10 of 15 patients, who were able to discontinue glucocorticoid therapy. Anti-TNF may be a useful adjunct to glucocorticoids in the treatment of TA. Our results justify a randomized, controlled clinical trial of anti-TNF therapy for TA.

Polymyalgia rheumatica/temporal arteritis: recent advances.

Polymyalgia rheumatica (PMR)/temporal arteritis (TA) frequently causes significant morbidity in patients older than 50 years of age. This review highlights recent trends in clinical findings, epidemiology, pathogenesis, and laboratory and radiologic assessment of the disease. Although steroids are the mainstay of therapy because of their effectiveness and ease of administration, they have numerous side effects, particularly in an aging population. Furthermore, recent evidence suggests that steroids only suppress clinical symptoms, while a smoldering level of damaging vascular inflammation persists. As a result, alternative agents are actively being investigated. We compare their successes and shortcomings and offer insight into their potential role in the treatment of this disease.

14. Immunologic rheumatic disorders.

We provide the basics for the clinician who might be called on to consider the diagnosis of diseases such as systemic lupus erythematosus (SLE) or rheumatoid arthritis (RA) in their practice. We will emphasize clinical recognition and first-line laboratory testing. Only characteristics of the classic rheumatic inflammatory diseases, RA, SLE, Sjögren syndrome, scleroderma, and dermatomyositis/polymyositis, will be covered. In the past decade, RA is the only disease for which treatment has substantially improved. The treatment of RA has been revolutionized by the use of methotrexate and, more recently, tumor necrosis factor inhibitors. The goal of RA treatment today is to induce a complete remission as early as possible in the disease process, with the mantra being "elimination of synovitis equals elimination of joint destruction." The hope is that if the major mediators of Sjögren syndrome or SLE or scleroderma can be identified and then blocked, as in the example of tumor necrosis factor inhibitors in RA, more specific treatments will become available. Thus, RA has become an excellent model of this evolving paradigm. Through the identification of major mediators in its pathogenesis, novel and highly efficacious therapeutic agents have been developed.