A systemic sclerosis and systemic lupus erythematosus pan-meta-GWAS reveals new shared susceptibility loci.

Systemic sclerosis (SSc) and systemic lupus erythematosus (SLE) are two archetypal systemic autoimmune diseases which have been shown to share multiple genetic susceptibility loci. In order to gain insight into the genetic basis of these diseases, we performed a pan-meta-analysis of two genome-wide association studies (GWASs) together with a replication stage including additional SSc and SLE cohorts. This increased the sample size to a total of 21,109 (6835 cases and 14,274 controls). We selected for replication 19 SNPs from the GWAS data. We were able to validate KIAA0319L (P = 3.31 × 10(-11), OR = 1.49) as novel susceptibility loci for SSc and SLE. Furthermore, we also determined that the previously described SLE susceptibility loci PXK (P = 3.27 × 10(-11), OR = 1.20) and JAZF1 (P = 1.11 × 10(-8), OR = 1.13) are shared with SSc. Supporting these new discoveries, we observed that KIAA0319L was overexpressed in peripheral blood cells of SSc and SLE patients compared with healthy controls. With these, we add three (KIAA0319L, PXK and JAZF1) and one (KIAA0319L) new susceptibility loci for SSc and SLE, respectively, increasing significantly the knowledge of the genetic basis of autoimmunity.

New insight on the Xq28 association with systemic sclerosis.

OBJECTIVE: To evaluate whether the systemic sclerosis (SSc)-associated IRAK1 non-synonymous single-nucleotide polymorphism rs1059702 is responsible for the Xq28 association with SSc or whether there are other independent signals in the nearby methyl-CpG-binding protein 2 gene (MECP2). METHODS: We analysed a total of 3065 women with SSc and 2630 unaffected controls from five independent Caucasian cohorts. Four tag single-nucleotide polymorphisms of MECP2 (rs3027935, rs17435, rs5987201 and rs5945175) and the IRAK1 variant rs1059702 were genotyped using TaqMan predesigned assays. A meta-analysis including all cohorts was performed to test the overall effect of these Xq28 polymorphisms on SSc. RESULTS: IRAK1 rs1059702 and MECP2 rs17435 were associated specifically with diffuse cutaneous SSc (PFDR=4.12×10(-3), OR=1.27, 95% CI 1.09 to 1.47, and PFDR=5.26×10(-4), OR=1.30, 95% CI 1.14 to 1.48, respectively), but conditional logistic regression analysis showed that the association of IRAK1 rs1059702 with this subtype was explained by that of MECP2 rs17435. On the other hand, IRAK1 rs1059702 was consistently associated with presence of pulmonary fibrosis (PF), because statistical significance was observed when comparing SSc patients PF+ versus controls (PFDR=0.039, OR=1.30, 95% CI 1.07 to 1.58) and SSc patients PF+ versus SSc patients PF- (p=0.025, OR=1.26, 95% CI 1.03 to 1.55). CONCLUSIONS: Our data clearly suggest the existence of two independent signals within the Xq28 region, one located in IRAK1 related to PF and another in MECP2 related to diffuse cutaneous SSc, indicating that both genes may have an impact on the clinical outcome of the disease.

Influence of the IL6 gene in susceptibility to systemic sclerosis.

OBJECTIVE: Systemic sclerosis (SSc) is a genetically complex autoimmune disease; the genetic component has not been fully defined. Interleukin 6 (IL-6) plays a crucial role in immunity and fibrosis, both key aspects of SSc. We investigated the influence of IL6 gene in the susceptibility and phenotype expression of SSc. METHODS: We performed a large metaanalysis including a total of 2749 cases and 3189 controls from 6 white populations (Germany, The Netherlands, Norway, Spain, Sweden, and United Kingdom). Three IL6 single-nucleotide polymorphisms (SNP; rs2069827, rs1800795, and rs2069840) were selected by SNP tagging and genotyped using TaqMan(®) allele discrimination technology. RESULTS: Individual SNP metaanalysis showed no evidence of association of the 3 IL6 genetic variants with the global disease. Phenotype analyses revealed a significant association between the minor allele of rs2069840 and the limited cutaneous SSc clinical form (Bonferroni p = 0.036, OR 1.14, 95% CI 1.04-1.25). A trend of association between the minor allele of the rs1800795 and the diffuse cutaneous SSc clinical form was also evident (Bonferroni p = 0.072, OR 0.86, 95% CI 0.77-0.96). In the IL6 allelic combination analyses, the GGC allelic combination rs2069827-rs1800795-rs2069840 showed an association with overall SSc (Bonferroni p = 0.016, OR 1.13, 95% CI 1.04-1.23). CONCLUSION: Our results suggest that the IL6 gene may influence the development of SSc and its progression.

Identification of CSK as a systemic sclerosis genetic risk factor through Genome Wide Association Study follow-up.

Systemic sclerosis (SSc) is complex autoimmune disease affecting the connective tissue; influenced by genetic and environmental components. Recently, we performed the first successful genome-wide association study (GWAS) of SSc. Here, we perform a large replication study to better dissect the genetic component of SSc. We selected 768 polymorphisms from the previous GWAS and genotyped them in seven replication cohorts from Europe. Overall significance was calculated for replicated significant SNPs by meta-analysis of the replication cohorts and replication-GWAS cohorts (3237 cases and 6097 controls). Six SNPs in regions not previously associated with SSc were selected for validation in another five independent cohorts, up to a total of 5270 SSc patients and 8326 controls. We found evidence for replication and overall genome-wide significance for one novel SSc genetic risk locus: CSK [P-value = 5.04 × 10(-12), odds ratio (OR) = 1.20]. Additionally, we found suggestive association in the loci PSD3 (P-value = 3.18 × 10(-7), OR = 1.36) and NFKB1 (P-value = 1.03 × 10(-6), OR = 1.14). Additionally, we strengthened the evidence for previously confirmed associations. This study significantly increases the number of known putative genetic risk factors for SSc, including the genes CSK, PSD3 and NFKB1, and further confirms six previously described ones.

Inflamación pulmonar latente en pacientes con esclerosis sistémic / Latent Pulmonary Inflammation in Patients With Systemic Sclerosis

Antecedentes: El esputo inducido es un método no invasivo para estudiar la inflamación pulmonar.ObjetivosEstudiar la inflamación pulmonar mediante el análisis de muestras de esputo inducido en pacientes con esclerosis sistémica y afección pulmonar, y determinar si existe correlación con las alteraciones de la función pulmonar observadas en estos pacientes. Métodos: Se incluyeron 25 pacientes con esclerosis sistémica (20 mujeres). Los pacientes fueron clasificados en 3 grupos, considerando el tipo de afección pulmonar: grupo 1, enfermedad pulmonar intersticial difusa (n=10); grupo 2, hipertensión arterial pulmonar (n=7), y grupo 3, pacientes con esclerosis sistémica sin afección pulmonar (n=8). A todos los pacientes se les realizó un estudio completo de función pulmonar y se obtuvieron muestras de esputo inducido. El recuento celular diferencial en las muestras de esputo se realizó mediante microscopia óptica. Resultados: El porcentaje medio de neutrófilos en esputo inducido fue del 85, del 71 y del 75% para los grupos 1, 2 y 3, respectivamente. Se observó una correlación negativa significativa entre el recuento celular total en esputo inducido y la DLCO en los grupos 1 y 3 (r=-0,733, p=0,016; y r=-0,893, p=0,007, respectivamente). Esta correlación negativa no se observó en el grupo 2. Conclusiones: En todos los pacientes con esclerosis sistémica incluidos en el estudio se detectó inflamación pulmonar, a pesar de la presencia o no de signos documentados de afección pulmonar. Este hallazgo sugiere que el esputo inducido podría ser una técnica útil para detectar anomalías tempranas indicativas de afección pulmonar subclínica en pacientes con esclerosis sistémica(AU)

Background: Induced sputum is a non-invasive method for studying pulmonary inflammation.ObjectivesTo assess pulmonary inflammation by analysis of induced sputum specimens in patients with systemic sclerosis and lung involvement, and to determine whether there is a correlation with the pulmonary function alterations in these patients. Methods: Twenty-five patients with systemic sclerosis were included (20 women). Patients were divided into 3 groups according to the type of lung involvement: group 1, diffuse interstitial lung disease (n=10); group 2, those with pulmonary arterial hypertension (n=7), and group 3, patients with systemic sclerosis without lung involvement (n=8). All patients underwent a complete lung function study. Induced sputum samples were obtained and differential cell count was performed by optic microscopy. Results: The mean percentage of sputum neutrophils was 85%, 71%, and 75% for groups 1, 2, and 3, respectively. A significant negative correlation between sputum total cell count and DLCO was seen in group 1 and group 3 (r=-0.733, P=.016; and r=-0.893, P=.007, respectively). This negative correlation was not observed in group 2. Conclusions: Pulmonary inflammation was present in all patients with systemic sclerosis included in the study, regardless of the presence of documented signs of pulmonary involvement. This finding suggests that induced sputum could be helpful for detecting early abnormalities indicative of subclinical pulmonary involvement in patients with systemic sclerosis(AU)

Analysis of Class II human leucocyte antigens in Italian and Spanish systemic sclerosis.

OBJECTIVE: To determine the role of Class II HLAs in SSc patients from Italy and Spain and in SSc patients of Caucasian ancestry. METHODS: Nine hundred and forty-four SSc patients (Italy 392 patients; Spain 452 patients) and 1320 ethnically matched healthy controls (Italy 398 patients; Spain 922 patients) were genotyped up to the fourth digit by PCR with sequence-specific oligonucleotides for HLA-DRB1, DQA1 and DQB1 loci. Patients included 390 ACA-positive and 254 anti-topo I-positive subjects. Associations between SSc or SSc-specific antibodies and HLA alleles or HLA haplotypes were sought via the chi-square test after 10 000-fold permutation testing. A meta-analysis including this study cohort and other Caucasoids samples was also conducted. RESULTS: In both the cohorts, the strongest association was observed between the HLA-DRB1*1104 allele and SSc or anti-topo I antibodies. The HLA-DRB1*1104 -DQA1*0501 -DQB1*0301 haplotype was overrepresented in Italian [odds ratio (OR) = 2.069, 95% asymptotic CIs (CI(95)) 1.486, 2.881; P < 0.001] and in Spanish patients (OR = 6.707, CI(95) 3.974, 11.319; P < 0.001) as well as in anti-topo-positive patients: Italy (OR = 2.642, CI(95) 1.78, 3.924; P < 0.001) and Spain (OR = 20.625, CI(95) 11.536, 36.876; P < 0.001). In both the populations we also identified an additional risk allele (HLA-DQB1*03) and a protective allele (HLA-DQB1*0501) in anti-topo-positive patients. The meta-analysis showed different statistically significant associations, the most interesting being the differential association between HLA-DRB1*01 alleles and ACAs (OR = 1.724, CI(95) 1.482, 2.005; P < 0.001) or topo I antibodies (OR = 0.5, CI(95) 0.384, 0.651; P < 0.001). CONCLUSIONS: We describe multiple robust associations between SSc and HLA Class II antigens in Caucasoids that may help to understand the genetic architecture of SSc.

Latent pulmonary inflammation in patients with systemic sclerosis.

BACKGROUND: Induced sputum is a non-invasive method for studying pulmonary inflammation. OBJECTIVES: To assess pulmonary inflammation by analysis of induced sputum specimens in patients with systemic sclerosis and lung involvement, and to determine whether there is a correlation with the pulmonary function alterations in these patients. METHODS: Twenty-five patients with systemic sclerosis were included (20 women). Patients were divided into 3 groups according to the type of lung involvement: group 1, diffuse interstitial lung disease (n=10); group 2, those with pulmonary arterial hypertension (n=7), and group 3, patients with systemic sclerosis without lung involvement (n=8). All patients underwent a complete lung function study. Induced sputum samples were obtained and differential cell count was performed by optic microscopy. RESULTS: The mean percentage of sputum neutrophils was 85%, 71%, and 75% for groups 1, 2, and 3, respectively. A significant negative correlation between sputum total cell count and DLCO was seen in group 1 and group 3 (r=-0.733, P=.016; and r=-0.893, P=.007, respectively). This negative correlation was not observed in group 2. CONCLUSIONS: Pulmonary inflammation was present in all patients with systemic sclerosis included in the study, regardless of the presence of documented signs of pulmonary involvement. This finding suggests that induced sputum could be helpful for detecting early abnormalities indicative of subclinical pulmonary involvement in patients with systemic sclerosis.

Identification of novel genetic markers associated with clinical phenotypes of systemic sclerosis through a genome-wide association strategy.

The aim of this study was to determine, through a genome-wide association study (GWAS), the genetic components contributing to different clinical sub-phenotypes of systemic sclerosis (SSc). We considered limited (lcSSc) and diffuse (dcSSc) cutaneous involvement, and the relationships with presence of the SSc-specific auto-antibodies, anti-centromere (ACA), and anti-topoisomerase I (ATA). Four GWAS cohorts, comprising 2,296 SSc patients and 5,171 healthy controls, were meta-analyzed looking for associations in the selected subgroups. Eighteen polymorphisms were further tested in nine independent cohorts comprising an additional 3,175 SSc patients and 4,971 controls. Conditional analysis for associated SNPs in the HLA region was performed to explore their independent association in antibody subgroups. Overall analysis showed that non-HLA polymorphism rs11642873 in IRF8 gene to be associated at GWAS level with lcSSc (P = 2.32×10(-12), OR = 0.75). Also, rs12540874 in GRB10 gene (P = 1.27 × 10(-6), OR = 1.15) and rs11047102 in SOX5 gene (P = 1.39×10(-7), OR = 1.36) showed a suggestive association with lcSSc and ACA subgroups respectively. In the HLA region, we observed highly associated allelic combinations in the HLA-DQB1 locus with ACA (P = 1.79×10(-61), OR = 2.48), in the HLA-DPA1/B1 loci with ATA (P = 4.57×10(-76), OR = 8.84), and in NOTCH4 with ACA P = 8.84×10(-21), OR = 0.55) and ATA (P = 1.14×10(-8), OR = 0.54). We have identified three new non-HLA genes (IRF8, GRB10, and SOX5) associated with SSc clinical and auto-antibody subgroups. Within the HLA region, HLA-DQB1, HLA-DPA1/B1, and NOTCH4 associations with SSc are likely confined to specific auto-antibodies. These data emphasize the differential genetic components of subphenotypes of SSc.

A replication study confirms the association of TNFSF4 (OX40L) polymorphisms with systemic sclerosis in a large European cohort.

OBJECTIVES: The aim of this study was to confirm the influence of TNFSF4 polymorphisms on systemic sclerosis (SSc) susceptibility and phenotypic features. METHODS: A total of 8 European populations of Caucasian ancestry were included, comprising 3014 patients with SSc and 3125 healthy controls. Four genetic variants of TNFSF4 gene promoter (rs1234314, rs844644, rs844648 and rs12039904) were selected as genetic markers. RESULTS: A pooled analysis revealed the association of rs1234314 and rs12039904 polymorphisms with SSc (OR 1.15, 95% CI 1.02 to 1.31; OR 1.18, 95% CI 1.08 to 1.29, respectively). Significant association of the four tested variants with patients with limited cutaneous SSc (lcSSc) was revealed (rs1234314 OR 1.22, 95% CI 1.07 to 1.38; rs844644 OR 0.91, 95% CI 0.83 to 0.99; rs844648 OR 1.10, 95% CI 1.01 to 1.20 and rs12039904 OR 1.20, 95% CI 1.09 to 1.33). Association of rs1234314, rs844648 and rs12039904 minor alleles with patients positive for anti-centromere antibodies (ACA) remained significant (OR 1.23, 95% CI 1.10 to 1.37; OR 1.12, 95% CI 1.01 to 1.25; OR 1.22, 95% CI 1.07 to 1.38, respectively). Haplotype analysis confirmed a protective haplotype associated with SSc, lcSSc and ACA positive subgroups (OR 0.88, 95% CI 0.82 to 0.96; OR 0.88, 95% CI 0.80 to 0.96; OR 0.86, 95% CI 0.77 to 0.97, respectively) and revealed a new risk haplotype associated with the same groups of patients (OR 1.14, 95% CI 1.03 to 1.26; OR 1.20, 95% CI 1.08 to 1.35; OR 1.23, 95% CI 1.07 to 1.42, respectively). CONCLUSIONS: The data confirm the influence of TNFSF4 polymorphisms in SSc genetic susceptibility, especially in subsets of patients positive for lcSSc and ACA.

[Usefulness of oral pilocarpin therapy in the treatment of xerostomia and xerophthalmia in patients with primary Sjögren's syndrome]. / Pilocarpina oral en el tratamientode la xerostomía y xeroftalmía en pacientes con síndrome de Sjögren primario.

BACKGROUND AND OBJECTIVE: We aimed to asses the efficacy of pilocarpine tablets as a symptomatic treatment for dry mouth and dry eyes in patients with primary Sjögren's syndrome (SS). PATIENTS AND METHOD: We included 40 patients with SS (38 women and 2 men), mean age 49.2 years (range, 35-68), with severe xerostomia and xerophthalmia. Objective tests (salivary scintigraphy, Schirmer's test, break-up time, Rose Bengal staining) and subjective tests (symptoms' questionnaire) were carried out before starting treatment and 6 months later to evaluate any glandular function improvement. RESULTS: All patients initially received 15 mg daily of pilocarpine. Twelve (30%) patients received 20 mg daily. Dry mouth-related symptoms improved in 57.5% of patients and dry eyes-related ones improved in 35%. Scintigraphic studies demonstrated an objective improvement of the glandular function in 35% patients. Ocular tests showed an improvement in 30% cases. CONCLUSIONS: Pilocarpine therapy is useful to improve xerostomia and xerophthalmia in SS patients with moderate and severe glandular involvement. However, we have not observed a good correlation between subjective improvement of symptoms and the objective test results.

Pilocarpina oral en el tratamiento de la xerostomía y xeroftalmía en pacientes con síndrome de Sjögren primario / Usefulness of oral pilocarpin therapy in the treatment of xerostomia and xerophtalmia in patients with primary Sjögren's syndrome

FUNDAMENTO Y OBJETIVO: Evaluar la eficacia de la pilocarpina en el tratamiento de la xerostomía y xeroftalmía en pacientes afectados de síndrome de Sjögren primario. PACIENTES Y MÉTODO: Se incluyó a 40 enfermos (38 mujeres y 2 varones), con una edad media de 49,2 años (intervalo, 35-68), con xerostomía y xeroftalmía intensas. Se practicaron pruebas objetivas (gammagrafía salival, prueba de Schirmer, tiempo de rotura lagrimal, tinción corneal con rosa de Bengala) y subjetivas (cuestionario de síntomas) para valorar la función glandular antes de inicio del tratamiento y a los 6 meses. RESULTADOS: Todos los pacientes recibieron inicialmente 15 mg/día de pilocarpina distribuidos en 3 tomas; 12 (30 por ciento) recibieron 20 mg/día. El 57,5 por ciento refirió mejoría subjetiva de la xerostomía y el 35 por ciento, de la xeroftalmía. La xerostomía mejoró objetivamente en el 35 por ciento de los pacientes y la xeroftalmía, en el 30 por ciento. CONCLUSIONES: El tratamiento con pilocarpina es beneficioso en pacientes con síndrome de Sjögren primario con moderada o escasa función glandular. No siempre existe una adecuada correlación entre la mejoría objetiva y la subjetiva (AU)