1. |
- López-Isac, Elena, et al.
(author)
-
Brief Report : IRF4 Newly Identified as a Common Susceptibility Locus for Systemic Sclerosis and Rheumatoid Arthritis in a Cross-Disease Meta-Analysis of Genome-Wide Association Studies
- 2016
-
In: Arthritis & Rheumatology. - : Wiley. - 2326-5191 .- 2326-5205. ; 68:9, s. 2338-2344
-
Journal article (peer-reviewed)abstract
- Objective: Systemic sclerosis (SSc) and rheumatoid arthritis (RA) are autoimmune diseases that have similar clinical and immunologic characteristics. To date, several shared SSc–RA genetic loci have been identified independently. The aim of the current study was to systematically search for new common SSc–RA loci through an interdisease meta–genome-wide association (meta-GWAS) strategy. Methods: The study was designed as a meta-analysis combining GWAS data sets of patients with SSc and patients with RA, using a strategy that allowed identification of loci with both same-direction and opposite-direction allelic effects. The top single-nucleotide polymorphisms were followed up in independent SSc and RA case–control cohorts. This allowed an increase in the sample size to a total of 8,830 patients with SSc, 16,870 patients with RA, and 43,393 healthy controls. Results: This cross-disease meta-analysis of the GWAS data sets identified several loci with nominal association signals (P < 5 × 10−6) that also showed evidence of association in the disease-specific GWAS scans. These loci included several genomic regions not previously reported as shared loci, as well as several risk factors that were previously found to be associated with both diseases. Follow-up analyses of the putatively new SSc–RA loci identified IRF4 as a shared risk factor for these 2 diseases (Pcombined = 3.29 × 10−12). Analysis of the biologic relevance of the known SSc–RA shared loci identified the type I interferon and interleukin-12 signaling pathways as the main common etiologic factors. Conclusion: This study identified a novel shared locus, IRF4, for the risk of SSc and RA, and highlighted the usefulness of a cross-disease GWAS meta-analysis strategy in the identification of common risk loci.
|
|
2. |
- Bossini-Castillo, Lara, et al.
(author)
-
Confirmation of association of the macrophage migration inhibitory factor gene with systemic sclerosis in a large European population.
- 2011
-
In: Rheumatology (Oxford, England). - : Oxford University Press (OUP). - 1462-0332 .- 1462-0324. ; 50, s. 1976-1981
-
Journal article (peer-reviewed)abstract
- Objectives. The aim of this study was to confirm the implication of macrophage migration inhibitory factor (MIF) gene in SSc susceptibility or clinical phenotypes in a large European population.Methods. A total of 3800 SSc patients and 4282 healthy controls of white Caucasian ancestry from eight different European countries were included in the study. The MIF -173 single nucleotide polymorphism (SNP) was selected as genetic marker and genotyped using Taqman 5' allelic discrimination assay.Results. The MIF -173 SNP showed association with SSc [P = 0.04, odds ratio (OR) = 1.10, 95% CI 1.00, 1.19]. Analysis of the MIF -173 polymorphism according to SSc clinical phenotype revealed that the frequency of the -173*C allele was significantly higher in the dcSSc group compared with controls (P = 5.30E-03, OR = 1.21, 95% CI 1.07, 1.38). Conversely, the frequency of the MIF -173*C allele was significantly underrepresented in the lcSSc group compared with dcSSc patients, supporting previous findings [(P = 0.04, OR = 0.86, 95% CI 0.75, 0.99); meta-analysis including previous results (P = 0.005, OR = 0.83, 95% CI 0.73, 0.94)].Conclusion. Our results confirm the role of MIF -173 promoter polymorphism in SSc, and provide evidence of a strong association with the dcSSc subgroup of patients. Hence, the MIF -173 variant is confirmed as a promising clinical phenotype genetic marker.
|
|
3. |
- Beal, Jacob, et al.
(author)
-
Robust estimation of bacterial cell count from optical density
- 2020
-
In: Communications Biology. - : Springer Science and Business Media LLC. - 2399-3642. ; 3:1
-
Journal article (peer-reviewed)abstract
- Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data.
|
|