Replication of recently identified systemic lupus erythematosus genetic associations: a case–control study

Introduction We aimed to replicate association of newly identified systemic lupus erythematosus (SLE) loci. Methods We selected the most associated SNP in 10 SLE loci. These 10 SNPs were analysed in 1,579 patients with SLE and 1,726 controls of European origin by single-base extension. Comparison of allele frequencies between cases and controls was done with the Mantel–Haenszel approach to account for heterogeneity between sample collections. Results A previously controversial association with a SNP in the TYK2 gene was replicated (odds ratio (OR) = 0.79, P = 2.5 × 10-5), as well as association with the X chromosome MECP2 gene (OR = 1.26, P = 0.00085 in women), which had only been reported in a single study, and association with four other loci, 1q25.1 (OR = 0.81, P = 0.0001), PXK (OR = 1.19, P = 0.0038), BANK1 (OR = 0.83, P = 0.006) and KIAA1542 (OR = 0.84, P = 0.001), which have been identified in a genome-wide association study, but not found in any other study. All these replications showed the same disease-associated allele as originally reported. No association was found with the LY9 SNP, which had been reported in a single study. Conclusions Our results confirm nine SLE loci. For six of them, TYK2, MECP2, 1q25.1, PXK, BANK1 and KIAA1542, this replication is important. The other three loci, ITGAM, STAT4 and C8orf13-BLK, were already clearly confirmed. Our results also suggest that MECP2 association has no influence in the sex bias of SLE, contrary to what has been proposed. In addition, none of the other associations seems important in this respectThe present work was supported by Fondo de Investigacion Sanitaria of the Instituto de Salud Carlos III (Spain), grants 04/1651 and 06/0620 that are partially financed by the Fondo Europeo de Desarrollo Regional program of the European Union, by grants from the Xunta de Galicia, and by BMBF KN Rheuma grant C2.12 (to TW)S

A comparison between the Simplified Disease Activity Index (SDAI) and the Disease Activity Score (DAS28) as measure of response to treatment in patients undergoing different therapeutic regimens

Objective: To compare the SDAI values to DAS28 scores in RA patients undergoing different DMARD regimens. Methods: The SDAI is an unweighted numerical sum of five outcome parameters: tender and swollen joint count (based on 28-joint assessment), patient and physician global assessment of disease activity (visual analogue scale: 0-10 cm) and level of C-reactive protein (mg/dl). 80 patients (F/M 68/12; age between 20-68 years, median 52) with active rheumatoid arthritis were prospectively enrolled in the study. The patients were randomly assigned to one of four groups according to the therapeutic regimens: group I: Methotrexate (MTX) 15 mg/weekly + salazopyrin 2 g/daily; group II: MTX 15 mg/weekly + infliximab 3 mg/Kg at time 0, 2, 4 and every 8 weeks; group III: MTX 15 mg/weekly + etanercept 25 mg/twice weekly; group IV: MTX 15 mg/weekly + adalimumab 40 mg/every other week. SDAI and DAS28 were determined at baseline and after 6 months in each patient. Mean changes in SDAI values were compared to those detected in DAS 28 at baseline and after 6 months. Results: SDAI and DAS 28 were found to be significantly correlated at baseline. Moreover, changes in SDAI over time paralleled those in DAS, and were found to be significantly correlated. Conclusions: SDAI is a valid measure of response to treatment in RA patients undergoing different therapeutic regimens

Low-dose aspirin as primary prophylaxis for cardiovascular events in systemic lupus erythematosus: A long-term retrospective cohort study

Objectives. Cardiovascular (CV) morbidity and mortality are significantly greater in SLE patients than in the general population. ASA is known to be associated with a decrease in the incidence of CV events in high-risk patients from the general population, but its efficacy as primary prophylaxis in SLE patients has not yet been investigated. Methods. The clinical charts of SLE patients consecutively admitted to a tertiary centre who, at admission, satisfied 1992 ACR and/or 2012 SLICC classification criteria for SLE and had not experienced any CV event, were reviewed. The occurrence of any CV event was recorded at each visit. ASA was prescribed to all patients at first visit. The rate and reasons for ASA discontinuation were also recorded at each visit.Results. One hundred and sixty-seven consecutive SLE patients were enrolled and followed up for a median of 8 years (range 1-14 years). Among them, 146 regularly took the medication (ASA-treated patients) and 21 refused to take or discontinued it (non-ASA-treated patients). Five CV events occurred in the 146 ASA-treated patients (4.2 per 1000 person-years) and four in the 21 non-ASA-treated patients (30 per 1000 person-years; P = 0.0007). The CV event-free rate was higher in ASA-treated than in non-ASA-treated patients (log-rank test χ2 = 15.74; P = 0.0001). No relevant side-effect related to ASA was recorded.Conclusion. Low-dose ASA is a safe treatment and may be beneficial in the primary prophylaxis of CV events in SLE patients. Controlled, prospective studies are needed to provide a better definition of its role in these patients

Association of Systemic Lupus Erythematosus Clinical Features with European Population Genetic Substructure

Systemic Lupus Erythematosus (SLE) is an autoimmune disease with a very varied spectrum of clinical manifestations that could be partly determined by genetic factors. We aimed to determine the relationship between prevalence of 11 clinical features and age of disease onset with European population genetic substructure. Data from 1413 patients of European ancestry recruited in nine countries was tested for association with genotypes of top ancestry informative markers. This analysis was done with logistic regression between phenotypes and genotypes or principal components extracted from them. We used a genetic additive model and adjusted for gender and disease duration. Three clinical features showed association with ancestry informative markers: autoantibody production defined as immunologic disorder (P = 6.8x10(-4)), oral ulcers (P = 6.9x10(-4)) and photosensitivity (P = 0.002). Immunologic disorder was associated with genotypes more common in Southern European ancestries, whereas the opposite trend was observed for photosensitivity. Oral ulcers were specifically more common in patients of Spanish and Portuguese self-reported ancestry. These results should be taken into account in future research and suggest new hypotheses and possible underlying mechanisms to be investigated. A first hypothesis linking photosensitivity with variation in skin pigmentation is suggested