Rheumatoid arthritis in African Colombians from Quibdo

A systematic review on time trend incidence of rheumatoid arthritis in outpatient rheumatology clinics

Objectives

To classify patients with rheumatoid arthritis (RA) in an earlier stage of the disease, the ACR/EULAR classification criteria were updated in 2010. These criteria might have led to an increased incidence of RA in the rheumatology clinic. Since a higher incidence increases the socio-economic burden of RA, it is worthwhile to evaluate whether there is a time effect.

Materials and methods

A systematic review was conducted using Embase, Medline Ovid, Cochrane Central, and Web of Science from database inception to February 2021. Included were only articles that addressed incidence rates of rheumatoid arthritis from rheumatology outpatient clinics.

Results

Of the 6,289 publications only 243 publications on RA were found eligible for full-text review. Nine studies were included reporting incidence. The pooled incidence for RA was 11% (95% CI 6-16%) per year. Over time the incidence increased after the introduction of the 2010 ACR/EULAR classification criteria. Overall there was a high intragroup heterogeneity (I 2 = 97.93%, p < 0.001), caused by geographical area, study design and differences in case definitions.

Conclusion

Although the incidence seems to increase after the introduction of the 2010 ACR/EULAR criteria, no conclusions can be drawn on this time effect due to heterogeneity.

Prevalence of rheumatoid arthritis in South America: a systematic review and meta-analysis

Rheumatoid arthritis (RA) is among the most prevalent chronic autoimmune and inflammatory diseases worldwide. The aim of this study was to establish a pooled estimate of the RA prevalence in South America by means of a meta-analysis of the available epidemiologic studies. Systematic searches in PubMed, Lilacs, SciELO, Scopus, and Web of Science databases (updated May 2019) were done followed by a systematic grey literature search to identify original research articles and reports, published after 2000, providing data of RA prevalence in any South American country. Proportion meta-analysis of weighted pooled was performed, with between-trial heterogeneity assessed by the inconsistency relative index. Sensitivity analyses and sub-group analyses were also done. A total of 25 articles, representing 27 population-based studies were included. Pooled prevalence of RA resulted in 0.48% with 591,981 cases in a population of 114,537,812 individuals (I2=99%). Brazil and Colombia presented the lowest rates of RA prevalence 0.22%, and 0.24%, respectively. RA prevalence in indigenous population was higher 1.45%, and studies using COPCORD method reported also the highest rates 1.07%.

Depressive and anxiety symptoms and social support are independently associated with disease-specific quality of life in Colombian patients with rheumatoid arthritis

OBJECTIVE

To examine the relationship between disease-specific Quality of Life (QOL) and socio-demographic, medical, and psychosocial factors in Colombian patients with Rheumatoid Arthritis (RA).

METHODS

One hundred and three RA patients recruited from ambulatory centers in Neiva, Colombia were administered the Disease Activity Scale 28 (DAS-28), QOL-RA, Zung Self-Rating Depression Scale, State-Trait Anxiety Inventory (STAI), Interpersonal Support Evaluation List-12 (ISEL-12), and Symptom Checklist-90 Revised (SCL-90R).

RESULTS

Lower QOL-RA was associated with lower socio-economic status (SES; r=0.26, p<0.01), higher likelihood of using opioids (t=-2.51, p<0.05), higher likelihood of comorbid pulmonary disease (t=-2.22, p<0.05), and lower ISEL-12 sub-scales (r's=0.41-0.31, p's<0.001). Lower QOL-RA was associated with higher DAS-28 (r=-0.28, p<0.01), Visual Analog Scale (VAS; r=-0.35, p<0.001), Zung Depression (r=-0.72, p <0.001), STAI-State (r=-0.66, p<0.001), STAI-Trait (r=-0.70, p<0.001), SCL-90R Global Severity Index (r=-0.50, p<0.001), SCL-90R Positive Symptom Total (r=-0.57, p<0.001), and all SCL-90R sub-scales (r's=-0.54--0.21, p's<0.01). A multivariate linear regression model indicated that SES (B=2.77, p<0.05), Zung Depression (B=-0.53, p<0.001), STAI-State (B=-0.26, p<0.05), and ISEL-12 Belonging (B=1.15, p<0.01) were independently associated with QOL-RA, controlling for significant associations.

CONCLUSIONS

More depressive and anxiety symptoms were independently associated with lower disease-specific QOL, while higher perceptions of having people to do activities with (belonging social support) and higher SES were independently associated with higher disease-specific QOL. Psychosocial factors impact QOL in RA above and beyond disease activity. Additional research into the benefits of psychosocial assessment of RA patients and provision of comprehensive care to improve QOL is warranted.

The effects of a pilot intervention for community-dwelling adults with rheumatoid arthritis in wuhan, china

This study examined the effects of a pilot educational intervention program on knowledge, perceived self-efficacy, and health-related quality of life (HRQoL) of community-dwelling adults with rheumatoid arthritis (RA). A convenience sample of 16 participants with RA completed the program in Wuhan, China. Data were collected in face-to-face interviews using questionnaires at baseline, post-test, and 1 month follow-up. Knowledge scores were significantly increased over time. Significant differences were found in pain self-efficacy, symptoms self-efficacy, bodily pain, social functioning, and role emotional functions. Community health providers should provide educational programs to improve HRQoL for adults with RA.

The phenotype and genotype of rheumatoid arthritis in the Democratic Republic of Congo

Introduction

Little is known about rheumatoid arthritis in the black, particularly in Congolese, populations. Our objective was to describe the phenotype and genotype of rheumatoid arthritis (RA) in Congolese.

Methods

All consecutive rheumatoid arthritis (RA) patients attending Kinshasa University Hospital in a three-year time period were included. Demographics, clinical features and tobacco consumption were noted. Disease Activity Score (DAS)-28 based on the erythrocyte sedimentation rate (ESR), Health Assessment Questionnaire (HAQ), anti-citrullinated peptide antibodies (CCP) antibodies and rheumatoid factor (RF) were determined. Radiographs were scored according to Sharp-van der Heijde. On a subset of patients and controls HLA-DRB1 typing was performed.

Results

A total of 114 females and 14 males aged 51.2 ± 14.9 were included. Mean duration of symptoms was four years. Moderate tobacco consumption was reported in a minority of patients. DAS-28 at first visit was >5.1 and HAQ ≥0.5 in all patients. X-rays showed joint erosions and/or joint space narrowing, mostly of a moderate grade in 55.8% of patients. Anti-CCP and/or RF were present in 48.6% of patients with available data (n = 72) and in 3.0% of controls (n = 67). Radiographic changes and nodules were more frequent in RF or anti-CCP positive patients. One copy of the shared epitope was found in 13 patients (35.1%) and 3 controls (12.5%). Two copies were found in one patient (2.7%) and in one control (4.2%).

Conclusion

Congolese patients with RA consult long after disease onset. Despite this delay, the majority presents without major damage and is RF, anti-CCP and SE negative. We put forward the hypothesis that besides different environmental factors there is probably also a particular genetic risk profile in Congolese patients, different from the HLA-DRB1 shared epitope.

Spatial modelling of rheumatoid arthritis in Turkey by geographic information systems (GIS)

We described the recent spatial distribution of rheumatoid arthritis in Turkey and assessed the role of environmental variables in this distribution. We developed an observed rheumatoid arthritis (RA) incidence grid map by using georeferenced rheumatoid arthritis case data (2011) from the centres of 81 provinces and the kriging method with a spherical variogram model in geographic information systems (GIS). We also modelled rheumatoid arthritis incidence in GIS by using complementary spatial database including the grid map layers of 14 environmental variables of Turkey. We conducted principle component analysis and multiple regression to investigate the relationships among variables and develop a model, respectively. The produced model was run in GIS to obtain a predicted (model) RA map. We tested the reliability of the model map by residual statistics and found the model map dependable. Observed and model incidence maps revealed the geographic distribution of rheumatoid arthritis cases in Turkey. The mean temperature, minimum temperature, maximum temperature, water vapour pressure, elevation, potential evapotranspiration, latitude, distance to seas, sunshine fraction, precipitation, longitude and aspect variables were found to have significant impacts on rheumatoid arthritis. Consequently, the model incidence map established a good background to predict rheumatoid arthritis cases following environmental changes.

Regional differences regarding risk of developing rheumatoid arthritis in Stockholm County, Sweden: results from the Swedish Epidemiological Investigation of Rheumatoid Arthritis (EIRA) study

OBJECTIVES

Rheumatoid arthritis (RA) is a complex disease that is associated with genetic and environmental factors. We have investigated geospatial variation in the risk of developing RA within Stockholm County, Sweden, with respect to established environmental risk factors for RA, as well as serologically defined subgroups of RA.

METHOD

Information regarding geographical location for 1432 cases and 2529 controls from the Epidemiological Investigation of Rheumatoid Arthritis (EIRA) study, living in Stockholm County at RA symptom onset, or matched date for controls, was used to estimate geospatial variation in risk. We used generalized additive models (GAMs) to create a risk surface, calculate odds ratios (ORs), and adjust for potential confounding by smoking, education level, and RA within family. We performed a stratified analysis based on the presence/absence of anti-citrullinated peptide antibodies (ACPA).

RESULTS

We found significant spatial variation in the odds of developing RA in Stockholm County. After adjustment for smoking, education level, and family history of RA, this geospatial variation remained. The stratified analysis showed areas with higher ORs for ACPA-positive RA and ACPA-negative RA, after adjusting for smoking, education level, and having a family history of RA. Living in the city of Stockholm was associated with decreased risk of RA.

CONCLUSIONS

The risk of developing RA in Stockholm County is not distributed evenly and there are areas of increased risk that could not be explained by known factors. Further investigations of local exposures or social factors are warranted.

Possible influence of resistance to malaria in clinical presentation of rheumatoid arthritis: biological significance of natural selection

Rheumatoid arthritis (RA) is a common autoimmune disease that affects all ethnic groups. Genetic factors, mainly HLA alleles, are highly associated with increased risk to develop RA. However, there are few available data about the role of these genetic polymorphisms in the prevalence or severity of RA in the Afrodescendant population, who have evolutionarily and by natural selection developed mutations that allowed them to acquire resistance to infectious diseases like malaria. Some of the mechanisms, by which this resistance was developed as a product of natural selection, are involved in different forms of immunological response, many of them of a well-known importance in the pathophysiology of RA. This paper focuses on presenting the known mechanisms of resistance to malaria and their possible contribution to the pathophysiology of RA, including "loss-of-function" mutations, lack of expression of chemokine receptors, decrease of immune complexes clearance by asplenia, or increase of immune reactivity mediated by B cells, among other mechanisms in this special group of patients.

Cardiovascular disease in rheumatoid arthritis: a systematic literature review in latin america

Background. Cardiovascular disease (CVD) is the major predictor of poor prognosis in rheumatoid arthritis (RA) patients. There is an increasing interest to identify "nontraditional" risk factors for this condition. Latin Americans (LA) are considered as a minority subpopulation and ethnically different due to admixture characteristics. To date, there are no systematic reviews of the literature published in LA and the Caribbean about CVD in RA patients. Methods. The systematic literature review was done by two blinded reviewers who independently assessed studies for eligibility. The search was completed through PubMed, LILACS, SciELO, and Virtual Health Library scientific databases. Results. The search retrieved 10,083 potential studies. A total of 16 articles concerning cardiovascular risk factors and measurement of any cardiovascular outcome in LA were included. The prevalence of CVD in LA patients with RA was 35.3%. Non-traditional risk factors associated to CVD in this population were HLA-DRB1 shared epitope alleles, rheumatoid factor, markers of chronic inflammation, long duration of RA, steroids, familial autoimmunity, and thrombogenic factors. Conclusions. There is limited data about CVD and RA in LA. We propose to evaluate cardiovascular risk factors comprehensively in the Latin RA patient and to generate specific public health policies in order to diminish morbi-mortality rates.

Changes Related to Age in Natural and Acquired Systemic Self-IgG Responses in Malaria

Background. Absence of acquired protective immunity in endemic areas children leads to higher susceptibility to severe malaria. To investigate the involvement of regulatory process related to self-reactivity, we evaluated potent changes in auto-antibody reactivity profiles in children and older subjects living in malaria-endemic zones comparatively to none-exposed healthy controls. Methods. Analysis of IgG self-reactive footprints was performed using Western blotting against healthy brain antigens. Plasmas of 102 malaria exposed individuals (MEIs) from endemic zone, with or without cerebral malaria (CM) were compared to plasmas from non-endemic controls (NECs). Using linear discriminant and principal component analysis, immune footprints were compared by counting the number, the presence or absence of reactive bands. We identified the most discriminant bands with respect to age and clinical status. Results. A higher number of bands were recognized by IgG auto-antibodies in MEI than in NEC. Characteristic changes in systemic self-IgG-reactive repertoire were found with antigenic bands that discriminate Plasmodium falciparum infections with or without CM according to age. 8 antigenic bands distributed in MEI compared with NEC were identified while 6 other antigenic bands were distributed within MEI according to the age and clinical status. Such distortion might be due to evolutionary processes leading to pathogenic/protective events.

Association between residences in U.S. northern latitudes and rheumatoid arthritis: A spatial analysis of the Nurses' Health Study

BACKGROUND

The etiology of rheumatoid arthritis (RA) remains largely unknown, although epidemiologic studies suggest genetic and environmental factors may play a role. Geographic variation in incident RA has been observed at the regional level.

OBJECTIVE

Spatial analyses are a useful tool for confirming existing exposure hypotheses or generating new ones. To further explore the association between location and RA risk, we analyzed individual-level data from U.S. women in the Nurses' Health Study, a nationwide cohort study.

METHODS

Participants included 461 incident RA cases and 9,220 controls with geocoded addresses; participants were followed from 1988 to 2002. We examined spatial variation using addresses at baseline in 1988 and at the time of case diagnosis or the censoring of controls. Generalized additive models (GAMs) were used to predict a continuous risk surface by smoothing on longitude and latitude while adjusting for known risk factors. Permutation tests were conducted to evaluate the overall importance of location and to identify, within the entire study area, those locations of statistically significant risk.

RESULTS

A statistically significant area of increased RA risk was identified in the northeast United States (p-value = 0.034). Risk was generally higher at northern latitudes, and it increased slightly when we used the nurses' 1988 locations compared with those at the time of diagnosis or censoring. Crude and adjusted models produced similar results.

CONCLUSIONS

Spatial analyses suggest women living in higher latitudes may be at greater risk for RA. Further, RA risk may be greater for locations that occur earlier in residential histories. These results illustrate the usefulness of GAM methods in generating hypotheses for future investigation and supporting existing hypotheses.

Radiographic severity of rheumatoid arthritis in African Americans: results from a multicenter observational study

OBJECTIVE

To describe radiographic changes in African Americans with rheumatoid arthritis (RA) from the Consortium for the Longitudinal Evaluations of African Americans with Early Rheumatoid Arthritis (CLEAR) Registry, a multicenter observational study.

METHODS

Self-declared African American patients were enrolled in CLEAR I, a longitudinal cohort of early RA (disease duration of <2 years) from 2000 to 2005, or in CLEAR II, a cross-sectional cohort (any disease duration) from 2006 to the present. Demographic and clinical data were obtained, and sets of hand/wrist and foot radiographs were scored using the modified Sharp/van der Heijde scoring system.

RESULTS

A total of 357 and 418 patients were enrolled in CLEAR I and CLEAR II, respectively. We report here an interim analysis of radiographic severity in these patients. For the CLEAR I cohort, 294 patients had a mean radiographic score of 2.89 at the baseline visit; 32.0% showed either erosions (25.9%) or joint space narrowing (JSN; 19.4%). At the 36-month visit, the mean score was 5.65; 44.2% had erosions, 41.5% had JSN, and 54.4% had either. Among those patients without radiographic damage at baseline, 18.9% had progressed at the 36-month visit, compared with 57.1% of those with baseline damage (P < 0.0001). For the CLEAR II cohort, of 167 patients with RA of any duration, 65.3% exhibited joint erosions, 65.3% exhibited JSN, and 74.8% exhibited either. The mean radiographic score was 33.42.

CONCLUSION

To our knowledge, this is the largest radiographic study of African American RA patients. Damage occurs early in the disease and is associated with radiographic progression at 3 years of disease duration. The CLEAR Registry will provide a valuable resource for future analyses of genetic, clinical, and environmental factors associated with radiographic severity of RA in African Americans.

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.

The environment, geo-epidemiology, and autoimmune disease: Rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic inflammatory joint disease characterized by a distinctive pattern of bone and joint destruction. RA patients have an increased risk of death. The incidence and prevalence of RA vary across populations, statistical methods, and disease definitions. In North America and Northern Europe, the incidence of RA is estimated at 20-50 cases per 100,000 population and the prevalence at 0.5-1.1%. Lower incidences and prevalences have been reported in Southern Europe, and few data are available for developing countries. Some studies showed declining incidences and prevalences after the 1960s. RA is a multifactorial disease that results from interactions between genetic and environmental factors. The main genetic factors are HLA-DRB1 and the tyrosine-phosphatase gene PTPN22. Among environmental factors implicated in the development of RA, smoking shows the strongest association with RA susceptibility and is also linked to worse outcomes. The aim of this review is to discuss the available data on the incidence and prevalence of RA, as well as the genetic and environmental risk factors associated with RA.

Presentation and severity of rheumatoid arthritis at diagnosis in Senegal

OBJECTIVE

Early effective treatment slows structural damage in RA but requires an early diagnosis. Our objective was to determine symptoms duration and presentation patterns of RA at diagnosis in Senegal.

METHODS

We conducted a cross-sectional study over a 2-year period (from March 2006 to February 2008) at the rheumatology clinic of the Le Dantec teaching hospital in Dakar, Senegal. Consecutive new patients who met ACR criteria for RA were included.

RESULTS

We included 100 patients, 88 females and 12 males, with a mean age of 40.3 +/- 15.5 years and a mean symptoms duration of 54 months. One-fourth of the patients had a positive family history. Pain was the main reason for the rheumatology clinic visit. Mean pain score was 64.3 mm on a 100-mm visual analogue scale. Nocturnal arousals were reported by 69% of the patients and morning stiffness for >1 h by 74%. The tender and swollen joint counts were 10 or higher in 87% and 36% of the patients, respectively, and the mean disease activity score on 28 joints (DAS28) was 6.49 +/- 1.34. Sicca syndrome (n = 13) and rheumatoid nodules (n = 3) were the main extra-articular manifestations. Laboratory evidence of inflammation was found in 87% and RF in 78% of the patients. Antibodies to cyclic citrullinated peptides (anti-CCPs) were detected in 26 of the 29 patients. Radiographical lesions were visible in 56% of the patients; mean modified Sharp score was 21.76 +/- 47.74.

CONCLUSION

The diagnosis of RA is delayed in Senegal, and the disease is highly active at diagnosis, although 44 patients have no erosions, and extra-articular manifestations are rare.

The impact of rheumatoid foot on disability in Colombian patients with rheumatoid arthritis

BACKGROUND

Alterations in the feet of patients with rheumatoid arthritis (RA) are a cause of disability in this population. The purpose of this research was to evaluate the impact that foot impairment has on the patients' global quality of life (QOL) based on validated scales and its relationship to disease activity.

METHODS

This was a cross-sectional study in which 95 patients with RA were enrolled. A complete physical examination, including a full foot assessment, was done. The Spanish versions of the Health Assessment Questionnaire (HAQ) Disability Index and of the Disease Activity Score (DAS 28) were administered. A logistic regression model was used to analyze data and obtain adjusted odds ratios (AORs).

RESULTS

Foot deformities were observed in 78 (82%) of the patients; hallux valgus (65%), medial longitudinal arch flattening (42%), claw toe (lesser toes) (39%), dorsiflexion restriction (tibiotalar) (34%), cock-up toe (lesser toes) (25%), and transverse arch flattening (25%) were the most frequent. In the logistic regression analysis (adjusted for age, gender and duration of disease), forefoot movement pain, subtalar movement pain, tibiotalar movement pain and plantarflexion restriction (tibiotalar) were strongly associated with disease activity and disability. The positive squeeze test was significantly associated with disability risk (AOR = 6,3; 95% CI, 1.28-30.96; P = 0,02); hallux valgus, and dorsiflexion restriction (tibiotalar) were associated with disease activity.

CONCLUSION

Foot abnormalities are associated with active joint disease and disability in RA. Foot examinations provide complementary information related to the disability as an indirect measurement of quality of life and activity of disease in daily practice.

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.

Latitude gradient influences the age of onset in rheumatoid arthritis patients

The mean age of rheumatoid arthritis (RA) onset is around 50 years as reported in several clinical trials involving Caucasian patients. However, clinical observations suggest that Mexican RA patients' disease is initiated at a younger age. The objective of the study was to assess whether the age of onset of RA is different in Mexican and in Canadian RA patients. Certified rheumatologists from Canada and Mexico directly interviewed consecutive RA patients attending their clinics regarding the date patients first noticed a swollen joint. None of the participant rheumatologists were aware of the primary aim of this exploratory study at the time of the interviews. Data was gathered from 161 Mexican (91% women) and 130 Canadian (77% women) RA patients collected by three rheumatologists in each country. Duration since disease onset was not different within countries (mean 95% confidence interval [CI] for differences -10 to 16 years, p = 0.12 for Canadians, and -6 to 10 years, p = 0.26, for Mexicans). However, there was a significant difference between the two countries. Mexicans patients on average developed RA almost 12 years younger than Canadians (95% CI for difference 9 to 15 years, p < 0.001). Frequency distribution showed that 35.5% of Canadians but only 4% of Mexicans had the onset of the disease after the age of 55 (all p < 0.001). It appears that RA begins at a much younger age in Mexican than Canadian patients. If this were confirmed after controlling for different confounders and biases, it would have important societal, economic, and therapeutic implications.

Meta-analysis of HLA-DRB1 polymorphism in Latin American patients with rheumatoid arthritis

OBJECTIVES

To estimate the common effect size of HLA-DRB1 alleles on rheumatoid arthritis (RA) susceptibility across Latin America populations through a meta-analysis combining the results of published data.

METHODS

Case-control studies on HLA-DRB1 association with RA in Latin America were searched up to October 2006. Genotype frequencies were extracted according to both shared epitope (SE) and HLA-DR4 positive or negative alleles. The effect summary odds ratio (OR) and 95% confidence intervals was obtained. Heterogeneity and publication bias were assessed.

RESULTS

Eight studies containing 684 cases and 1015 controls were included. Under the random effects model, the common OR was 3.28 (1.93, 5.60) (p<0.0001) and 3.54 (2.47, 5.05) (p=4.22 x 10(-12)) for HLA-DR4 and SE, respectively. There was no evidence of publication bias according to Funnel plot and Egger's regression test (p=0,445 for DR4 and p=0,464 for SE meta-analysis). Significant heterogeneity was observed for HLA-DR4 (I2=81.06%, Q=36.96, p=0.000005) but not for the SE meta-analysis.

CONCLUSIONS

HLA-DR4 and SE positive HLA-DRB1 alleles (mainly HLA-DRB10404) are associated with RA in Latin Americans. Heterogeneity is expected owing to the diverse degree of admixture between the examined populations. Our findings support the HLA as a major susceptibility locus for RA and validate the SE hypothesis in Latin America.

Rheumatic diseases in minority populations

Rheumatic diseases are expressed in all ethnic populations, but differ in prevalence, genetic associations, clinical features, and responses to interventions. Most data describing these differences do so in reference to and comparisons with white populations. These are sparse data that evaluate differences within minority populations where there is more homogeneity of external factors, such as social, cultural, and behavioral attitudes. This article reviews the features that are unique to various rheumatic diseases within minority populations.

HLA class II and TNF genes in African Americans from the Southeastern United States: regional differences in allele frequencies

Knowledge of population major histocompatibility complex gene frequencies is important for construction of organ donor pools and for studies of disease association. Human leukocyte antigen DRB1 (HLA-DRB1), HLA-DQB1, and TNFalpha -308 (G-A) promoter genetic typing was performed in 112 healthy, unrelated African Americans (AAs) from the southeastern United States. Allele frequencies were compared with published frequency data from other AA populations. Our AA population had the highest frequency of HLA- DRB1*09 (6.7%) reported in any AA population. The frequency of the TNF alpha -308A polymorphism was also high (14.4%), when compared with published frequencies in AAs. Significant regional differences in the distribution of most HLA-DRB1 and HLA-DQB1 alleles were observed in all AA populations examined. The AA HLA-DRB1 and -DQB1 frequencies also differed from published Caucasian frequencies. This is the first report describing the distribution of TNF alpha promoter alleles in the Southeastern United States. The high DRB1*09 and TNF alpha -308A allele frequencies of our population most resemble the frequencies of these alleles in certain West African populations. These varying major histocompatibility complex gene frequencies may reflect different regional population structures among AAs in the United States, which may be due to differences in ancestral origins, migration, and racial admixture.

The Impact of Disease Activity on the Quality of Life, Mental Health Status, and Family Dysfunction in Colombian Patients With Rheumatoid Arthritis

This study investigated the relationship between activity of disease, mental health status, quality of life, and family dysfunction in northwestern Colombian patients with rheumatoid arthritis (RA). Seventy-nine patients completed a 2-phase study that included physical examination (objective measurement of disease activity according to adapted American College of Rheumatology criteria) and a pretested questionnaire that sought information on helplessness, disability, depression, anxiety, quality of life, arthritis self-efficacy for pain, and other symptoms, as well as family dysfunction and socioeconomic status. Nineteen patients (24%) had active RA, 48 (61%) had moderately active RA, and 12 (15%) were in remission. Symptoms of depression, helplessness, disability, pain, anxiety, lower quality of life, and self-efficacy were associated with RA activity regardless of age, sex, and duration of the disease. Symptoms of depression were directly correlated with anxiety, helplessness, pain, and disability and inversely correlated with quality of life and self-efficacy. Although family dysfunction was present in 39% of patients, no associations between family dysfunction, activity of RA, mental health variables, socioeconomical status or quality of life were observed. These results indicate that RA activity significantly influences mental health status and quality of life in this population. Accordingly, a holistic conception of therapy should guide the treatment of patients with RA.

Central Nervous System Compromise in Primary Sjögren’s Syndrome

Central nervous system (CNS) involvement in primary Sjögren's syndrome (SS) is poorly understood, and its frequency as well as its manifestations are subjects of controversy. The current study was undertaken to determine the prevalence and the clinical and immunogenetic characteristics of CNS compromise in a well defined group of patients with primary SS. In this retrospective study, patients fulfilled the European classification criteria. Among 120 patients with primary SS, 3 (2.5%) had CNS compromise (multiple sclerosis-like illness, complicated migraine, and optic neuritis with epilepsy). The CNS involvement coincided with the onset of sicca symptoms in 1 case. All 3 patients carried the human leukocyte antigen (HLA) DQB1*0303 allele and tested positive for anti-Ro antibodies, but not for anti-cardiolipin antibodies. Although rare, CNS compromise in primary SS can be the presenting manifestation of the disease in a few cases, and may be severe and varied.

TAP, HLA-DQB1, and HLA-DRB1 polymorphism in Colombian patients with primary Sjögren's syndrome

OBJECTIVE

Although primary Sjögren's syndrome (pSS) has a worldwide distribution, little data is available on pSS immunogenetics in non-white populations. Thus, we investigated the influence of transporters associated with antigen processing (TAP), human leukocyte antigen (HLA)-DQB1, and HLA-DRB1 gene polymorphism in mestizo Colombian patients with pSS.

METHODS

In this cross-sectional and controlled study, all patients met the European criteria for classification of pSS. TAP and HLA typing was performed by polymerase chain reaction techniques. Genetic data analysis was performed to detect deviations from the expected Hardy-Weinberg (H-W) proportions and to determine the presence of population stratification or subdivision and the existence of linkage disequilibrium between pairs of loci.

RESULTS

Seventy-three Colombian patients with pSS (95% women) and 76 healthy controls were studied. Although significant associations were not observed between TAP or HLA polymorphism and disease, strong linkage disequilibrium among the loci TAP2 and DQB1 was found in patients. Deviations from the H-W expected value were found in the DQB1 locus of patients (P =.02). HLA-DRB1*0301-DQB1*0201 haplotype was associated with more severe histopathologic disease (odds ratio [OR], 15.5; 95% confidence interval [CI], 1.9-129; P =.001) and the presence of anti-Ro (OR, 3.8; 95% CI, 1-15; P =.04) and anti-La antibodies (OR, 4.3; 95% CI, 1.3-14; P =.01).

CONCLUSION

The data show genetic evidence suggesting that, in Colombians, a region immersed or in the vicinity in the HLA class II system is strongly associated with a predisposition to acquire pSS, which is probably located between the TAP2 and HLA-DQB1 locus. Our results confirm that the HLA-DRB1*0301-DQB1*0201 haplotype participates in the pathogenesis of pSS.