Prevalence of musculoskeletal disorders and rheumatic diseases in an Argentinean indigenous Wichi community

OBJECTIVE

To estimate the prevalence of musculoskeletal disorders (MSK) and rheumatic diseases in an indigenous Wichi population in Argentina.

METHODS

This is a cross-sectional, community-based study using the Community-Oriented Program for the Control of Rheumatic Diseases (COPCORD) methodology in ≥ 18-year-old subjects. Validated surveys were conducted by trained interviewers. Subjects with MSK pain (positive cases) were evaluated by internists and rheumatologists for diagnosis and treatment.

RESULTS

A total of 648 interviews were performed (90.4% of the census population). Mean age was 37.5 years (SD 14.8), and 379 (58.5%) were female. The mean years of education was 7.0 (SD 3.7); 552 subjects (85.2%) were covered by the public health care system. A total of 216 (33.3%) subjects had MSK pain in the last 7 days. Rheumatic disease prevalence was as follows: mechanical back pain (19.0%), rheumatic regional pain syndrome (5.2%), osteoarthritis (3.2%), rheumatoid arthritis (RA) (3.2%), inflammatory back pain (1.2%), undifferentiated arthritis (0.3%), Sjögren syndrome (0.15%), and fibromyalgia (0.15%). RA patients included 19 (90.5%) women and 9 (42.9%) with RA family history. One hundred percent were seropositive and 66.7% showed radiologic erosions. The mean of Disease Activity Score [DAS-28 (ESR)] at the time of diagnosis was 5.1 (SD 1.5) and the Health Assessment Questionnaire Disability Index (HAQ-DI) was 0.8 (SD 0.4).

CONCLUSION

RA prevalence was 3.2%, one of the highest reported using the COPCORD methodology in indigenous and non-indigenous peoples in Latin America, with a high percentage of family cases. Pain and functional capacity were the variables allowing patients' early referral to a specialist. Key Points • The RA prevalence was 3.2%, one of the highest reported using COPCORD methodology in indigenous and non-indigenous peoples in Latin America. • The patients with RA had high percentage of familiar history of RA. • The pain and functional capacity were the variables associated with a diagnosis of any rheumatic disease and should be considered for early referral. • The mean of the delay in the diagnosis was 5.8 years. In this community, the lack of the "migration health" phenomenon may be a social determinant that negatively impacts their health.

[Prevalence of dyslipidemia and elevated cardiovascular risk in patients with rheumatoid arthritis]

The objectives of this study were to compare the frequency of dyslipidemia (DLP) and the elevated cardiovascular risk between rheumatoid arthritis (RA) patients and a control group, to identify disease-related factors associated with the presence of DLP and to estimate the frequency of RA patients receiving treatment for DLP. This is a cross sectional study that included 409 RA patients and 624 controls. Cardiovascular (CV) risk was determined using the Framingham score, National Cholesterol Education Program (NCEP) and the Systematic Coronary Risk Evaluation (SCORE) adapted versions according to the European League Against Rheumatism (EULAR) guidelines. DLP was defined according to the Adult Treatment Panel III (ATPIII). The frequency of CV risk was similar in RA patients and controls, except when NCEP-EULAR adapted version for RA was applied (7% vs. 2%; p = 0.00002). A 43% of patients and 47% of controls had DLP (p = 0.15). RA patients with DLP tended to have extra-articular manifestations more frequently (36% vs. 24%; p = 0.01) and higher erythrocyte sedimentation rate (ESR) (21 [13-35] vs. 18 [10-30] mm; p = 0.003). RA patients treated for DLP varied between 11% and 32% according to the definition used. Patients with RA showed an elevated CV risk only when the NCEP-EULAR definition was used. Among RA patients, those with higher ESR and the presence of extra-articular manifestations were more likely to show DLP. The vast majority of patients were not receiving treatment for DLP.

Fine mapping of Xq28: both MECP2 and IRAK1 contribute to risk for systemic lupus erythematosus in multiple ancestral groups

OBJECTIVES

The Xq28 region containing IRAK1 and MECP2 has been identified as a risk locus for systemic lupus erythematosus (SLE) in previous genetic association studies. However, due to the strong linkage disequilibrium between IRAK1 and MECP2, it remains unclear which gene is affected by the underlying causal variant(s) conferring risk of SLE.

METHODS

We fine-mapped ≥136 SNPs in a ∼227 kb region on Xq28, containing IRAK1, MECP2 and seven adjacent genes (L1CAM, AVPR2, ARHGAP4, NAA10, RENBP, HCFC1 and TMEM187), for association with SLE in 15 783 case-control subjects derived from four different ancestral groups.

RESULTS

Multiple SNPs showed strong association with SLE in European Americans, Asians and Hispanics at p<5×10(-8) with consistent association in subjects with African ancestry. Of these, six SNPs located in the TMEM187-IRAK1-MECP2 region captured the underlying causal variant(s) residing in a common risk haplotype shared by all four ancestral groups. Among them, rs1059702 best explained the Xq28 association signals in conditional testings and exhibited the strongest p value in transancestral meta-analysis (p(meta )= 1.3×10(-27), OR=1.43), and thus was considered to be the most likely causal variant. The risk allele of rs1059702 results in the amino acid substitution S196F in IRAK1 and had previously been shown to increase NF-κB activity in vitro. We also found that the homozygous risk genotype of rs1059702 was associated with lower mRNA levels of MECP2, but not IRAK1, in SLE patients (p=0.0012) and healthy controls (p=0.0064).

CONCLUSIONS

These data suggest contributions of both IRAK1 and MECP2 to SLE susceptibility.