Rheumatoid Arthritis: del Rincón I

del Rincón I, Escalante A. · University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA. · Curr Rheumatol Rep. · Pubmed #16174491 No free full text.

Abstract: Tumor necrosis factor-alpha (TNF-alpha) antagonists were unexpectedly found to have no beneficial effects in moderate-to-severe heart failure in two large randomized clinical trials. In certain doses, the agents were found to be harmful. These results have important implications for rheumatoid arthritis (RA). Patients with the disease have an increased risk for developing cardiovascular co-morbidity, including heart failure. Because of the beneficial effect of the TNF-alpha antagonists in the management of RA, these agents have gained widespread use. Rheumatologists and other physicians who provide care for RA are thus likely to encounter candidates for anti-TNF-alpha therapy who have overt or subclinical heart failure. Although data are currently not sufficient to support evidence-based recommendations, it is possible to make reasonable suggestions to guide clinical practice.

del Rincón I, Escalante A. · Division of Clinical Immunology and Rheumatology, Department of Medicine, The University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX 78229, USA. · Curr Rheumatol Rep. · Pubmed #14531955 No free full text.

Abstract: The past 3 years have seen a remarkable growth in the interest of cardiovascular disease in rheumatoid arthritis. There have been studies published documenting an increased incidence and prevalence of cardiovascular conditions in patients with rheumatoid arthritis compared with individuals without rheumatoid arthritis. There has also been interest in the occurrence of cardiovascular risk factors in rheumatoid arthritis and in the role of antirheumatic therapy, including cyclooxygenase-2 selective nonsteroidal anti-inflammatory drugs, methotrexate, corticosteroids, and tumor necrosis factor inhibitors. A number of studies using noninvasive means to detect atherosclerosis have shown that patients with rheumatoid arthritis may be prone to atherosclerosis. This information should be important to physicians who provide care to patients with rheumatoid arthritis, given the difficulty of recognizing cardiovascular signs and symptoms among patients with the disease.

Escalante A, del Rincón I. · Division of Clinical Immunology and Rheumatology, Department of Medicine, The University of Texas Health Science Center at San Antonio, San Antonio, Texas 78229, USA. · Curr Opin Rheumatol. · Pubmed #11224734 No free full text.

Abstract: The emergence of a sizable Hispanic population in the US is a relatively recent historical phenomenon, and thus much is still unknown about this group of North Americans. Data from national surveys suggest small differences between Hispanic and non-Hispanic white populations in the age-adjusted prevalence of self-reported arthritic conditions. However, the rate of activity-limitation attributable to arthritis is higher among Hispanic patients. This likely reflects the poorer socioeconomic conditions and lack of health insurance that prevail among Hispanic populations, which may limit their access to rheumatologic care. Osteoporotic vertebral and hip fractures are less frequent, and proximal femoral mineral density is higher, in Hispanic individuals than in non-Hispanic white individuals. The mechanisms for these observations are currently under investigation. There have been no studies of the prevalence of osteoarthritis, rheumatoid arthritis, or systemic lupus erythematosus among Hispanic populations. However, important immunogenetic, clinical, and psychosocial differences between Hispanic and non-Hispanic patients in regard to rheumatoid arthritis and systemic lupus erythematosus have been reported. There is no published information on the prevalence or characteristics of other rheumatic diseases in the US Hispanic population. Emerging evidence suggests considerable underuse of certain health services for arthritis among Hispanic patients, likely due in part to socioeconomic factors. Further research is needed to determine whether biologic, cultural or psychosocial factors contribute to underuse as well. There is clearly a need for data on the prevalence and characteristics of arthritis and other rheumatic and musculoskeletal diseases in this emerging US population.

Roldán JF, Escalante A, del Rincón I. · The University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA. · Arthritis Rheum. · Pubmed #18383416 links to  free full text

Abstract: OBJECTIVE: To evaluate the association between peripheral arterial function and cortical bone thickness in rheumatoid arthritis (RA). METHODS: In a cross-sectional study, we measured the combined cortical thickness (CCT) of the second metacarpal bone from hand radiographs, and the ankle-to-arm systolic blood pressure ratio, also known as ankle-brachial index (ABI), in RA patients. We evaluated the association between the 2 using multinomial logistic regression. RESULTS: We obtained CCT and ABI measurements in 588 RA patients. The mean +/- SD CCT was 3.62 +/- 1.16 mm. The proportion of patients with > or =1 ABI value < or =0.9, indicating obstructed lower limb arteries, increased from 18 (9.2%) of 191 patients in the highest CCT tertile to 25 (12.5%) of 200 in the middle CCT tertile to 38 (19.2%) of 198 in the lowest CCT tertile (P for trend 0.005). We noted a similar pattern for ABI values >1.3, indicative of arterial incompressibility (frequencies in high, middle, and low CCT tertiles were 4.7%, 9.5%, and 19.9%, respectively; P for trend < or =0.001). These trends remained significant after multivariable adjustment for potential confounders. After adjustment for the manifestations of RA and cumulative glucocorticoid dose, the association between CCT and arterial obstruction remained significant, but that with arterial incompressibility weakened considerably. CONCLUSION: There is an association between metacarpal cortical bone thinning and obstruction or incompressibility of the peripheral arteries in RA. The association with incompressibility may be mediated by systemic inflammation and/or glucocorticoids, but that with obstruction is independent of a wide array of potential confounders. Clinicians should be alert to the possibility of impaired arterial function RA patients with thinned metacarpal cortical bone.

del Rincón I, Freeman GL, Haas RW, O'Leary DH, Escalante A. · University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX 78229-3900, USA. · Arthritis Rheum. · Pubmed #16255018 links to  free full text

Abstract: OBJECTIVE: To estimate the contribution of cardiovascular (CV) risk factors and rheumatoid arthritis (RA) disease manifestations to atherosclerosis in RA. METHODS: We used high-resolution carotid ultrasound to measure the carotid intima-media thickness (IMT) and plaque in 631 RA patients. Using R(2) measures from multivariable models, we estimated the contribution of demographic characteristics (age, sex, and ethnic group), CV risk factors (diabetes mellitus, hypercholesterolemia, cigarette smoking, hypertension, and body mass index, and RA manifestations (joint tenderness, swelling, and deformity, nodules, erythrocyte sedimentation rate [ESR], C-reactive protein, rheumatoid factor, the HLA-DRB1 shared epitope, and cumulative glucocorticoid dose) to each of the outcomes. Estimates were obtained in the full sample, and within strata defined by age, sex, and ethnic group. We tested for interaction between CV risk factors and RA manifestations. RESULTS: The contribution of demographic factors, CV risk factors, and RA manifestations to IMT and plaque R(2) varied depending on the patients' age stratum. Demographic features explained 11-16% of IMT variance, CV risk factors explained 4%-12%, and RA manifestations explained 1-6%. The greatest contribution of RA manifestations occurred in the youngest age group, while that of CV risk factors occurred in the older age groups. Results for carotid plaque were similar. There was a significant interaction between the number of CV risk factors present and the ESR, suggesting that the ESR's effect on IMT varied according to the number of CV risk factors. CONCLUSION: Both established CV risk factors and manifestations of RA inflammation contribute significantly to carotid atherosclerosis in RA, and may modify one another's effects. These findings may have implications regarding the prevention of atherosclerosis in RA.

Escalante A, Haas RW, del Rincón I. · Division of Rheumatology and Clinical Immunology, Department of Medicine, The University of Texas Health Science Center at San Antonio, 78229-3900, USA. · Arch Intern Med. · Pubmed #16043681 links to  free full text

Abstract: BACKGROUND: Despite high cardiovascular mortality in rheumatoid arthritis (RA), few studies of body mass index (BMI) and obesity as risk factors for death in RA have been published. METHODS: We estimated the effect of BMI on survival in a cohort of 779 patients with RA adjusting for comorbidity, RA disease severity, erythrocyte sedimentation rate (ESR), and other potential confounders. RESULTS: The cohort accrued 123 deaths in 3460 person-years (3.6 deaths per 100 person-years; 95% confidence interval [CI], 3.0-4.2). The BMI was inversely associated with mortality. Patients with BMIs of 30 or higher had the lowest mortality, 1.7 deaths per 100 person-years (95% CI, 1.1-2.5). Mortality was higher in each lower BMI category, reaching its highest rate among patients with BMIs lower than 20 with 15.0 deaths per 100 person-years (95% CI, 9.9-23.0). The survival advantage of high BMI was independent of RA onset age, RA duration, sex, ethnic group, socioeconomic status, smoking status, and use of methotrexate but was lost on adjusting for comorbidity and RA severity. We observed an interaction between BMI and ESR, where the BMI protective influence occurred only if the ESR was low. The BMI x ESR interaction was independent of all covariates, including comorbidity and RA severity. CONCLUSIONS: Body mass has a paradoxical effect on mortality in RA. Patients with high BMI have lower mortality than thinner patients. This effect is mediated in part by comorbidity. The effect of body mass on survival seems to be modified by the level of systemic inflammation.

Escalante A, Haas RW, del Rincón I. · Division of Rheumatology and Clinical Immunology, Department of Medicine, The University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA. · BMC Musculoskelet Disord. · Pubmed #15769287 links to  free full text

Abstract: BACKGROUND: We have previously proposed a theoretical model for studying physical disability and other outcomes in rheumatoid arthritis (RA). The purpose of this paper is to test a model of impairment and functional limitation in (RA), using empirical data from a sample of RA patients. We based the model on the disablement process framework. METHODS: We posited two distinct types of impairment in RA: 1) Joint inflammation, measured by the tender, painful and swollen joint counts; and 2) Joint deformity, measured by the deformed joint count. We hypothesized direct paths from the two impairments to functional limitation, measured by the shirt-button speed, grip strength and walking velocity. We used structural equation modeling to test the hypothetical relationships, using empirical data from a sample of RA patients recruited from six rheumatology clinics. RESULTS: The RA sample was comprised of 779 RA patients. In the structural equation model, the joint inflammation impairment displayed a strong significant path toward the measured variables of joint pain, tenderness and swelling (standardized regression coefficients 0.758, 0.872 and 0.512, P <or= 0.001 for each). The joint deformity impairment likewise displayed significant paths toward the measured upper limb, lower limb, and other deformed joint counts (standardized regression coefficients 0.849, 0.785, 0.308, P <or= 0.001 for each). Both the joint inflammation and joint deformity impairments displayed strong direct paths toward functional limitation (standardized regression coefficients of -0.576 and -0.564, respectively, P <or= 0.001 for each), and explained 65% of its variance. Model fit to data was fair to good, as evidenced by a comparative fit index of 0.975, and the root mean square error of approximation = 0.058. CONCLUSION: This evidence supports the occurrence of two distinct impairments in RA, joint inflammation and joint deformity, that together, contribute strongly to functional limitations in this disease. These findings may have implications for investigators aiming to measure outcome in RA.

del Rincón I, O'Leary DH, Haas RW, Escalante A. · The University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA. · Arthritis Rheum. · Pubmed #15593231 links to  free full text

Abstract: OBJECTIVE: Glucocorticoids are suspected to cause atherosclerosis. Because of the possibility that their antiinflammatory effect may be antiatherogenic, this study investigated the effect of glucocorticoids on the arteries of patients with rheumatoid arthritis (RA). METHODS: We assessed the arteries of 647 patients with RA. Central atherosclerosis was measured using high-resolution carotid ultrasound for the presence of plaque and for the extent of carotid artery intima-media thickness (CaIMT). Peripheral atherosclerosis was assessed using the systolic pressures of the dorsal pedal, posterior tibial, and brachial arteries to obtain the ankle-brachial index (ABI). Cumulative glucocorticoid dose was determined using pharmacy records, supplemented by self-report. Cardiovascular (CV) risk factors and RA clinical manifestations were ascertained using clinical and laboratory methods. RESULTS: Among the RA patients studied, 427 (66%) had received glucocorticoids. Of those who had never received glucocorticoids, 100 (47%) of 215 had carotid plaque and 17 (8%) of 219 had > or =1 incompressible lower-limb artery (ABI >1.3). Among patients in the highest tertile of lifetime glucocorticoid exposure (>16.24 gm prednisone), the frequency of carotid plaque increased to 85 (62%) of 138 (P = 0.006) and that of lower-limb arterial incompressibility increased to 24 (17%) of 140 (P = 0.008), with differences remaining significant after adjustment for age at onset, disease duration, sex, CV risk factors, and RA clinical manifestations (tender, swollen, and deformed joint counts, subcutaneous nodules, rheumatoid factor seropositivity, and erythrocyte sedimentation rate). The CaIMT also displayed an increase with higher glucocorticoid exposure, but the differences did not reach significance. Lower-limb artery obstruction (ABI < or =0.9) was not associated with glucocorticoid exposure. CONCLUSION: In this RA sample, glucocorticoid exposure was associated with carotid plaque and arterial incompressibility, independent of CV risk factors and RA clinical manifestations. This supports a role for glucocorticoids in the CV complications that occur in RA.

del Rincón I, Haas RW, Pogosian S, Escalante A. · Division of Clinical Immunology and Rheumatology, The University of Texas Health Science Center at San Antonio, Texas 78229, USA. · Ann Rheum Dis. · Pubmed #15271772 links to  free full text

Abstract: BACKGROUND: Despite increased cardiovascular morbidity and mortality in rheumatoid arthritis, the peripheral arteries remain understudied. OBJECTIVE: To examine the lower limb arteries in age and sex matched, non-smoking subjects with and without rheumatoid arthritis. METHODS: The ankle-brachial index (ABI) was measured at the posterior tibial and dorsal pedal arteries. Arteries were classified as obstructed with ABI < or =0.9, normal with ABI >0.9 but < or =1.3, and incompressible with ABI >1.3. Multinomial logistic regression was used to estimate differences in ABI between patients and controls, adjusting for cardiovascular risk factors, rheumatoid arthritis manifestations, inflammation markers, and glucocorticoid dose. RESULTS: 234 patients with rheumatoid arthritis and 102 controls were studied. Among the rheumatoid patients, 66 of 931 arteries (7%) were incompressible and 30 (3%) were obstructed. Among the controls, three of 408 arteries (0.7%) were incompressible (p = 0.002) and four (1%) were obstructed (p = 0.06). At the person level, one or more abnormal arteries occurred among 45 rheumatoid patients (19%), v five controls (5%, p = 0.001). The greater frequency of arterial incompressibility and obstruction in rheumatoid arthritis was independent of age, sex, and cardiovascular risk factors. Adjustment for inflammation markers, joint damage, rheumatoid factor, and glucocorticoid use reduced rheumatoid arthritis v control differences. Most arterial impairments occurred in rheumatoid patients with 20 or more deformed joints. This subgroup had more incompressible (15%, p< or =0.001) and obstructed arteries (6%, p = 0.005) than the controls, independent of covariates. CONCLUSIONS: Peripheral arterial incompressibility and obstruction are increased in rheumatoid arthritis. Their propensity for patients with advanced joint damage suggests shared pathogenic mechanisms.

Escalante A, Haas RW, del Rincón I. · Division of Rheumatology and Clinical Immunology, Department of Medicine, The University of Texas Health Science Center at San Antonio, San Antonio, TX, USA. · Arthritis Res Ther. · Pubmed #15225367 links to  free full text

Abstract: Outcome assessment in patients with rheumatoid arthritis (RA) includes measurement of physical function. We derived a scale to quantify global physical function in RA, using three performance-based rheumatology function tests (RFTs). We measured grip strength, walking velocity, and shirt button speed in consecutive RA patients attending scheduled appointments at six rheumatology clinics, repeating these measurements after a median interval of 1 year. We extracted the underlying latent variable using principal component factor analysis. We used the Bayesian information criterion to assess the global physical function scale's cross-sectional fit to criterion standards. The criteria were joint tenderness, swelling, and deformity, pain, physical disability, current work status, and vital status at 6 years after study enrolment. We computed Guyatt's responsiveness statistic for improvement according to the American College of Rheumatology (ACR) definition. Baseline functional performance data were available for 777 patients, and follow-up data were available for 681. Mean +/- standard deviation for each RFT at baseline were: grip strength, 14 +/- 10 kg; walking velocity, 194 +/- 82 ft/min; and shirt button speed, 7.1 +/- 3.8 buttons/min. Grip strength and walking velocity departed significantly from normality. The three RFTs loaded strongly on a single factor that explained >or=70% of their combined variance. We rescaled the factor to vary from 0 to 100. Its mean +/- standard deviation was 41 +/- 20, with a normal distribution. The new global scale had a stronger fit than the primary RFT to most of the criterion standards. It correlated more strongly with physical disability at follow-up and was more responsive to improvement defined according to the ACR20 and ACR50 definitions. We conclude that a performance-based physical function scale extracted from three RFTs has acceptable distributional and measurement properties and is responsive to clinically meaningful change. It provides a parsimonious scale to measure global physical function in RA.

Escalante A, del Rincón I, Mulrow CD. · Division of Clinical Immunology and Rheumatology, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX 78284, USA. · Arthritis Care Res. · Pubmed #14635289 No free full text.

Abstract: OBJECTIVE: To explore the roles played by Hispanic ethnic background and acculturation to the mainstream English language culture of the United States in the depressive symptoms and mental health of rheumatoid arthritis (RA) patients. METHODS: Members of a consecutive cohort of patients with RA were studied cross-sectionally. All underwent a comprehensive clinical and psychosocial evaluation. Depressive symptoms were measured with the Center for Epidemiologic Studies Depression Scale (CES-D), and psychological distress was measured with the Medical Outcomes Study Short Form 36 (SF-36) mental health scale. RESULTS: Two hundred thirty-six patients were studied. Women had significantly higher median CES-D scores than men (19 versus 14, P = 0.0004), Hispanics scored higher than non-Hispanics (14 versus 8, P = 0.0002), and foreign-born scored higher than US-born patients (14 versus 10, P = 0.009). Compared with those who were fully acculturated, patients who were partially acculturated were more likely to have a score > or = 16 on the RA-adjusted CES-D (odds ratio [OR] = 1.79, 95% confidence interval [95% CI] 1.37 to 2.35, P < or = 0.001). Among unacculturated patients, the likelihood of a score > or = 16 increased 6-fold (OR = 6.68; 95% CI 3.50 to 12.72; P < or = 0.001). A similar, inverse pattern was observed for the SF-36 mental health scale. In multivariate models accounting for age, sex, education, income, articular pain, deformity, and the level of disability, low acculturation was independently associated with high depressive symptoms, and a Hispanic background was independently associated with lower SF-36 mental health. CONCLUSIONS: In this consecutive series of RA patients, Hispanics, particularly those who are not fully acculturated to the mainstream Anglo society, had more depressive symptoms and psychological distress than did non-Hispanics.

del Rincón I, Battafarano DF, Arroyo RA, Murphy FT, Escalante A. · The University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX 78229-7874, USA. · Arthritis Rheum. · Pubmed #12115177 links to  free full text

Abstract: OBJECTIVE: To test the hypothesis that the influence of the HLA-DRB1 shared epitope (SE) on the clinical manifestations of rheumatoid arthritis (RA) differs between men and women. METHODS: We assessed 777 consecutive RA patients for age at disease onset, articular manifestations, subcutaneous nodules, laboratory and radiographic findings, and treatment received. We typed HLA-DRB1 alleles by polymerase chain reaction-sequence-specific primer amplification and categorized the number of SE-containing alleles. We used regression models to adjust comparisons between the sexes for age and clustering by recruitment center, and included SE x sex interaction terms to look for heterogeneity between men and women in the effect of the SE. RESULTS: Among the 777 RA patients, 548 (71%) were women. Men and women differed significantly in the adjusted frequency of SE positivity (women 71.4% versus men 78.4%; P < or = 0.001). The SE was associated with a younger age at symptom onset and RA diagnosis among men, but not among women. The SE likewise had a significant adverse effect on joint tenderness, swelling, and deformity among men only. The SE was associated with a higher erythrocyte sedimentation rate in women and more frequent positivity for rheumatoid factor among both men and women. CONCLUSION: There is heterogeneity between men and women in the effect of the SE on RA susceptibility and clinical expression. Further research is needed to understand the mechanism of this heterogeneity.

Escalante A, Cardiel MH, del Rincón I, Suárez-Mendoza AA. · Division of Clinical Immunology and Rheumatology, University of Texas Health Science Center at San Antonio 78284, USA. · Arthritis Care Res. · Pubmed #11081004 No free full text.

Abstract: OBJECTIVE: To show evidence of the cross-cultural equivalence between the original English version of a 5-item scale for measuring helplessness and a translated Spanish version. METHODS: English and Spanish versions of the 5 items that constitute the helplessness factor of the Rheumatology Attitudes Index were tested in 3 separate groups of patients: 1) 20 bilingual rheumatology patients; 2) 100 consecutive English- and 50 consecutive Spanish-speaking monolingual rheumatology patients; and 3) 192 English- and 44 Spanish-speaking patients with rheumatoid arthritis who were consecutively enrolled in a cohort to study disease outcomes. English-Spanish concordance among bilingual subjects was measured using intraclass correlation coefficients (ICC). Internal consistency was measured by Cronbach's coefficient alpha. Associations between the helplessness scale and variables measured simultaneously in English- and Spanish-speaking patients were measured by correlation analysis. RESULTS: Agreement between the English and Spanish versions of the helplessness scale among bilingual subjects was excellent (ICC = 0.87), and internal consistency among monolingual subjects was acceptable (coefficient alpha = 0.73 in English and 0.87 in Spanish). The correlation between helplessness and most other measured variables was of similar size and direction in English as in Spanish (10-point pain scale r = -0.53 and -0.52; modified Health Assessment Questionnaire physical disability r = -0.45 and -0.43; self-assessed joint count r = 0.36 and 0.36; Medical Outcomes Study Short Form 36 [SF-36] physical function r = 0.37 and 0.39; SF-36 mental health r = 0.27 and 0.35; Center for Epidemiological Studies Depression scale r = -0.37 and -0.33, respectively). CONCLUSION: The evidence shown supports the cross-cultural equivalence between the original 5-item helplessness scale developed in English and our translated Spanish version.

del Rincón I, Roldán JF. · University of Texas Health Science Center at San Antonio, USA. · Arthritis Rheum. · Pubmed #10555053 No free full text.

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Escalante A, del Rincón I. · The University of Texas Health Science Center, San Antonio 78284, USA. · Arthritis Rheum. · Pubmed #10446872 links to  free full text

Abstract: OBJECTIVE: To measure the proportion of disability explained by disease manifestations compared with nondisease factors in rheumatoid arthritis (RA). METHODS: A hypothetical model of the disablement process specific for RA was constructed using the demographic, sociocultural, and clinical characteristics of a consecutive cohort of RA patients. Disability was measured with the modified Health Assessment Questionnaire (M-HAQ) and the physical function scale of the Medical Outcomes Study Short Form 36 (SF-36) questionnaire. Independent variables, grouped according to their position in the RA disablement process model, were sequentially entered in a series of hierarchical regression models. The proportion of variance in disability explained by each group of variables was measured by the group's incremental R2. RESULTS: The overall proportion of disability explained by the full model was 59%. Factors in the main disease-disability pathway explained 33%, of which 3% was explained by disease duration, 5% by the Westergren erythrocyte sedimentation rate, 14% by articular signs and symptoms, and 11% by performance-based functional limitations. External modifiers and contextual variables explained 26% of the variance in disability, of which age and sex accounted for 2%, formal education 4%, psychological status 17%, and symptoms of depression 3%. CONCLUSION: Both the main disease-disability pathway and factors external to this pathway contribute significantly to disability in RA. These findings provide evidence of the relative influence of psychosocial factors, compared with disease manifestations, on the disability of patients with RA.

del Rincón I, Escalante A. · The University of Texas Health Science Center at San Antonio, 78284, USA. · Arthritis Rheum. · Pubmed #10403259 links to  free full text

Abstract: OBJECTIVE: To study the genetics (HLA-DRB1 allele associations) of rheumatoid arthritis (RA) susceptibility and severity among Mexican Americans, an important, but understudied, US population. METHODS: HLA-DRB1 alleles were compared between 141 Mexican American patients with RA and 54 unrelated Mexican Americans without RA, and the association of these alleles with articular deformities and disability was examined. HLA-DRB1 alleles were typed using polymerase chain reaction-sequence-specific primer amplification and were classified according to the 1996 World Health Organization nomenclature. RESULTS: Of the 141 patients, 105 (74%) had at least 1 copy of the shared epitope (SE) sequence, compared with 29 (54%) of the 54 controls (P = 0.007). A significant gene-dose effect was observed, with 31 patients (22%) being homozygous for the SE compared with 1 (2%) of the controls (P = 0.004). In terms of disease severity, only 3% of RA patients who were "null" for the SE were outliers in the rate of development of articular deformities, compared with 10% of heterozygotes and 27% of homozygotes (P = 0.002). Patients who were DRB1*08 positive had significantly fewer deformities per year of disease and a slower rate of development of disability than did patients with other DRB1 alleles. CONCLUSION: HLA-DRB1 alleles containing the SE are associated with susceptibility to RA in Mexican Americans, and may also be associated with a more rapid development of articular deformities and disability. HLA-DRB1*08 appears to have a protective influence on RA susceptibility and disease severity in Mexican Americans.

Escalante A, del Rincón I. · No affiliation provided · N Engl J Med. · Pubmed #10383274 No free full text.

This publication has no abstract.