The complex HLA-E-nonapeptide in Behçet disease.

Introduction: The knowledge of the aetiology of Behçet disease (BD), an immune-mediated vasculitis, is limited. HLA-B, mainly HLA-B51, and HLA-A molecules are associated with disease, but the ultimate cause of this association remains obscure. There is evidence that NK cells participate in the etiopathology of BD. NK cells have activator and inhibitor surface receptors, like the KIR and the NKG2 families. Classical HLA-class I molecules (A, B and C) are keys in the activity control of the NK because they are KIR ligands. Most NKG2 receptors bind HLA-E, which presents only nonapeptides derived from the signal peptide of other class-I molecules. Objective: This study investigates the contribution of the pair HLA-E and ligand, nonapeptide derived from the 3-11 sequence of the signal peptides of class I classical molecules, to the susceptibility to BD. Methods: We analyzed the frequency of the HLA-derivated nonapeptide forms in 466 BD patients and 444 controls and an HLA-E functional dimorphism in a subgroup of patients and controls. Results: In B51 negative patients, the frequency of VMAPRTLLL was lower (70.4% versus 80.0% in controls; P=0.006, Pc=0.04, OR=0.60, 95%CI 0.41-0.86), and the frequency of VMAPRTLVL was higher (81.6% versus 71.4% in controls; P=0.004, Pc=0.03, OR=1.78, 95%CI 1.20-2.63). In homozygosity, VMAPRTLLL is protective, and VMAPRTLVL confers risk. The heterozygous condition is neutral. There were no significant differences in the distribution of the HLA-E dimorphism. Discussion: Our results explain the association of BD with diverse HLA-A molecules, reinforce the hypothesis of the involvement of the NK cells in the disease and do not suggest a significant contribution of the HLA-E polymorphism to disease susceptibility.

Protein and functional isoform levels and genetic variants of the BAFF and APRIL pathway components in systemic lupus erythematosus.

Systemic lupus erythematosus (SLE) is the prototype of an autoimmune disease. Belimumab, a monoclonal antibody targets BAFF, is the only biologic approved for SLE and active lupus nephritis. BAFF is a cytokine with a key-regulatory role in the B cell homeostasis, which acts by binding to three receptors: BAFF-R, TACI and BCMA. TACI and BCMA also bind APRIL. Many studies reported elevated soluble BAFF and APRIL levels in the sera of SLE patients, but other questions about the role of this system in the disease remain open. The study aimed to investigate the utility of the cytokine levels in serum and urine as biomarkers, the role of non-functional isoforms, and the association of gene variants with the disease. This case-control study includes a cohort (women, 18-60 years old) of 100 patients (48% with nephritis) and 100 healthy controls. We used ELISA assays to measure the cytokine concentrations in serum (sBAFF and sAPRIL) and urine (uBAFF and uAPRIL); TaqMan Gene Expression Assays to quantify the relative mRNA expression of ΔBAFF, ßAPRIL, and εAPRIL, and next-generation sequencing to genotype the cytokine (TNFSF13 and TNFSF13B) and receptor (TNFRSF13B, TNFRSF17 and TNFRSF13C) genes. The statistical tests used were: Kruskal-Wallis (qualitative variables), the Spearman Rho coefficient (correlations), the Chi-square and SKAT (association of common and rare genetic variants, respectively). As expected, sBAFF and sAPRIL levels were higher in patients than in controls (p ≤ 0.001) but found differences between patient subgroups. sBAFF and sAPRIL significantly correlated only in patients with nephritis (rs = 0.67, p ≤ 0.001) and ßAPRIL levels were lower in patients with nephritis (p = 0.04), and ΔBAFF levels were lower in patients with dsDNA antibodies (p = 0.04). Rare variants of TNFSF13 and TNFRSF13B and TNFSF13 p.Gly67Arg and TNFRSF13B p.Val220Ala were associated with SLE. Our study supports differences among SLE patient subgroups with diverse clinical features in the BAFF/APRIL pathway. In addition, it suggests the involvement of genetic variants in the susceptibility to the disease.

Spanish scleroderma risk score (RESCLESCORE) to predict 15-year all-cause mortality in scleroderma patients at the time of diagnosis based on the RESCLE cohort: Derivation and internal validation.

A few scores predicting the short-term risk of mortality in Systemic sclerosis (SSc) have been reported to date. Our study aimed to create a predictive 15-year all-cause mortality score at the time of the diagnosis of SSc. The study was based on the Spanish Scleroderma Registry (RESCLE). The cohort was split up in derivation (DC) and validation cohort (VC). A multivariate analysis to detect variables related to all-cause mortality within the first 15 years from SSc diagnosis was performed, assigning points to the rounded beta values to create the score (RESCLESCORE). 1935 SSc patients were included. The variables in the final model were as follows: age at diagnosis (+2 points > 65 years-old), male gender (+1 point), lcSSc subset (-1 point), mode of onset other than Raynaud's (+1 point), cancer (+1 point) and visceral involvement, such as ILD (+1 point), PAH (+1 point), heart (+1 point) and renal involvement (+2 points). Autoantibodies did not achieve statistical significance in the multivariate analysis. The 3 categories of risk to predict 15-year all-cause mortality at the time of diagnosis were as follows: low risk (5% vs. 7%, p = .189), intermediate risk (26.5% vs. 25.5%, p = .911) and high risk (47.8% vs. 59%, p = .316). The AUC was 0.799 (DC) vs. 0.778 (VC) (p = .530). In conclusion, the RESCLESCORE demonstrated an excellent ability to categorize SSc patients at the time of diagnosis in separate 15-year all-cause mortality risk strata at the time of diagnosis.

Behçet's disease and genetic interactions between HLA-B*51 and variants in genes of autoinflammatory syndromes.

Behçet's disease (BD) is an immune-mediated systemic disorder with a well-established genetic base. In a previous study, using a next generation sequencing approach, we found many rare variants and some functional polymorphisms in genes related to autoinflammatory syndromes (AID): CECR1, MEFV, MVK, NLRP3, NOD2, PSTPIP1 and TNFRSF1A in our BD cohort. Our strategy did not allow us to establish either number of patients with variants, proportion of individuals accumulating them or relationship with other genetic factors. With the goal to answer these questions, the individual samples were sequenced. Additionally, three functional polymorphisms: NLRP3 p.Gln703Lys, NOD2 p.Arg702Trp and p.Val955Ile were genotyped using TaqMan assays. A total of 98 patients (27.6%) carried at least one rare variant and 13 of them (3.7%) accumulated two or three. Functional regression model analysis suggests epistatic interaction between B51 and MEFV (P = 0.003). A suggestive protective association of the minor allele of NOD2 p.Arg702Trp (P = 0.01) was found in both, B51 positive and negative individuals. Therefore, a high percentage of patients with BD have rare variants in AID genes. Our results suggest that the association of MEFV with BD could be modulated by the HLA molecules; whereas the protective effect of NOD2 p.Arg702Trp would be independent of HLA.

Clinical and epidemiological differences between men and women with systemic sclerosis: a study in a Spanish systemic sclerosis cohort and literature review.

OBJECTIVES: The low overall prevalence of systemic sclerosis (SSc) and the low proportion of male patients have resulted in a scarcity of studies assessing sex differences in Ssc patients, and contradictory results have often been show among those studies that have been performed. METHODS: A prospective study was conducted with the Spanish RESCLE register to analyse the influence of gender on survival of SSc patients. RESULTS: In total, 1506 SSc patients (1341 women, 165 men) were recruited from 21 centres. Older age at onset (OR 1.02), shorter time from onset to diagnosis (OR 0.96), smoking (OR 2.57), interstitial lung disease (ILD) (OR 1.58), less predisposition to sicca syndrome and to antinuclear antibody positivity (OR 0.29 and 0.43, respectively), and higher compliance with the ACR 1980 criteria (OR 1.79) were independently associated with the male sex. During follow-up, 30.4% of men versus 14.6% of women died (p<0.001). Survival at 10 years from the onset of symptoms was 75.3% for men and 92.9% for women (p<0.001), and the difference remained after selecting only SSc-related deaths (85.6% vs. 96.1%, p<0.001). The mortality predictive factors were diffuse SSc (OR 2.26), ILD (OR 1.82), digital ulcers (OR 1.38), tendon friction rubs (OR 1.74), male sex (OR 1.53), increased age at onset (OR 1.13) and isolated PH (considering only deaths from diagnosis), both in the overall (OR 3.63) and female cohorts (OR 3.97). The same risk factors were observed in the male cohort, except for isolated PH and ILD. CONCLUSIONS: The present study confirms the existence of epidemiological, clinical, laboratory and prognostic gender differences in systemic sclerosis patients.

Mutational profile of rare variants in inflammasome-related genes in Behçet disease: A Next Generation Sequencing approach.

Behçet's disease (BD) is an immune-mediated systemic disorder with a well-established association with HLA class I and other genes. BD has clinical overlap with many autoinflammatory diseases (AIDs). The aim of this study was to investigate the role of rare variants in seven genes involved in AIDs: CECR1, MEFV, MVK, NLRP3, NOD2, PSTPIP1 and TNFRSF1A using a next generation sequencing (NGS) approach in 355 BD patients. To check global association of each gene, 4 tests: SKAT, CollapseBt, C(α) and weighted KBAC were used. Databases: 1000 Genomes Project Phase 3, Infevers, HGMD and ClinVar and algorithms: PolyPhen2 and SIFT were consulted to collect information of the 62 variants found. All the genes resulted associated using SKAT but only 3 (MVK, NOD2 and PSTPIP1) with C(α) and weighted KBAC. When all the genes are considered, 40 variants were associated to AIDs in clinical databases and 25 were predicted as pathogenic at least by one of the algorithms. Including only MVK, NOD2 and PSTPIP1, the associated to AIDs variants found in BD were 20 and the predicted as pathogenic, 12. The maxima contribution corresponds to NOD2. This study supports influence of rare variants in genes involved in AIDs in the pathogenesis of BD.

Clinical manifestations and long-term outcome of anti-Jo1 antisynthetase patients in a large cohort of Spanish patients from the GEAS-IIM group.

OBJECTIVE: To evaluate the clinical manifestations, long-term clinical outcome and longitudinal pulmonary function in a large cohort of Spanish patients with anti-Jo1 antibodies. METHODS: We retrospectively analyzed the clinical data and lung function parameters of 148 anti-Jo1 patients recruited from a multicentre registry including 18 Spanish hospitals. A composite endpoint was defined, comprising death due to respiratory failure directly related to antisynthetase syndrome (ASS), the need for long-term oxygen therapy or lung transplantation. RESULTS: Median follow-up was 78.3 months. Clinical presentation patterns at onset are as follows: isolated interstitial lung disease (ILD) (32.4%), isolated myositis (26.9%), concomitant myositis and ILD (22.8%), and isolated polyarthritis (17.9%). Myositis with ILD was the most frequent final clinical phenotype (67.6%). In most ASS patients, ILD was a non-progressive disease, tending to stabilize with therapy. The endpoint was reached in a significantly larger number of ILD patients with dyspnea at onset than those with paucisymptomatic or asymptomatic forms (p = 0.01). A steady FVC decrease was the hallmark of patients with end-stage lung disease. Estimated survival rates were 87.7% and 75.4% at 5 and 10 years, respectively. Cancer (p = 0.02) and advanced age at ASS diagnosis (p < 0.0001) were related to poorer survival. Mortality was significantly higher than in the general Spanish population, with a standardised mortality ratio (95% CI) of 4.03 (2.79-5.64). CONCLUSIONS: Anti-Jo1 ASS is a heterogeneous syndrome. ILD in ASS under immunosuppressive therapy is mainly a non-progressive disease. Dyspnea at ILD onset and a steady FVC decrease over time were related to a poorer respiratory prognosis.

[Screening of pulmonary hypertension in a Spanish cohort of patients with systemic sclerosis]. / Cribado de hipertensión pulmonar en una cohorte española de pacientes con esclerosis sistémica.

BACKGROUND AND OBJECTIVE: Pulmonary arterial hypertension (PAH) is an important cause of morbimortality in systemic sclerosis (SSc). Evolution is worse than that of subjects with idiopathic PAH, but prognosis improves when PAH is diagnosed early. The aim of this research is to describe results of a screening program for diagnosis of pulmonary hypertension (PH) carried out in a cohort of Spanish patients with SSc. PATIENTS AND METHOD: PH screening was performed by transthoracic doppler echocardiography (TTDE) in 184 patients with SSc. Patients with systolic pulmonary arterial pressure estimated by TTDE>35 mmHg were evaluated per protocol to confirm diagnosis and type of PH. RESULTS: PAH was diagnosed in 25 patients (13.6%). Patients with diffuse and limited SSc developed PAH in a similar degree, 9/60 (15%) vs. 16/100 (16%), with no cases among patients with SSc "sine scleroderma" or "pre-scleroderma" (P<.001). The only clinical or epidemiological data characterizing patients with PAH were older age (mean age 67 years for patients with PAH vs. 56 years for those without PAH, P=.007), limited SSc, a trend toward shorter evolution of the underlying disease (median 8 years for patients with PAH vs. 10 years for those without PAH, P=.73), and a higher frequency of positive anticentromere antibodies (16 patients [64%] with PAH vs. 70 (48,3%) without PAH, P=.19). CONCLUSIONS: Prevalence of PAH in SSc was high and supports the implementation of a regular screening program.

Association of haplotypes of the TLR8 locus with susceptibility to Crohn's and Behçet's diseases.

OBJECTIVES: The aim of this study was to investigate the role of the TLR8, a mediator of innate inflammatory response, in susceptibility to two immune-mediated disorders characterised by dysregulation of the immune response, Crohn's and Behçet's diseases (CD and BD). METHODS: A total of 844 CD, 371 BD patients and 1385 controls were genotyped in 8 tag single nucleotide polymorphisms (tSNPs) in the locus TLR8 (chromosome X). All these tSNPs have a minor allele frequency greater than 0.05 in the Caucasian population. RESULTS: The rs2407992 and the rs5744067 were associated with susceptibility to BD and CD, respectively (OR=1.34, 95%CI=1.10-1.62, p=0.0025 and OR=0.82, 95%CI=0.68-0.99, p=0.045, respectively). Although after stratification by gender, statistically significant differences in the distribution of the aforementioned SNPs were only observed in the females groups (BD OR=1.31, 95%CI=1.06-1.64, p=0.012 and CD OR=0.84, 95%CI=0.72-0.98, p=0.044) the trend was similar among males. Since the rs5744067 and rs2407992 are located in the same linkage disequilibrium block, we performed a haplotypic analysis by combination of the tSNPs. One haplotype (H1) was identified as a protective factor in BD (OR=0.75, 95%CI=0.62-0.90, p=0.0027) and another (H2) as a protective factor in CD (OR=0.78, 95%CI=0.64-094, p=0.0102). No statistically significant differences in the mean of the levels of expression attributable to the haplotype variants were found in the in silico analysis performed. CONCLUSIONS: Our results suggest a relationship between the TLR8 and the susceptibility to CD and BD. Nevertheless, these differences could not be imputed to the levels of expression.

Lack of association of TNFAIP3 and JAK1 with Behçet's disease in the European population.

OBJECTIVES: Behçet's disease (BD) is an immune-mediated and complex disease which has been associated with HLA class I molecules although other genes such as IL23R and IL10 have also been involved in the susceptibility to BD. Recently, an association of variants of the JAK1 and TNFAIP3 genes with the disease has been reported in the Chinese Han population. The aim of the present work was to asses whether the association described in Asian populations is replicated in Europeans. METHODS: This study includes a total of 1155 Spanish subjects of European origin (372 BD and 783 unrelated healthy individuals). Patients were recruited from different hospitals and controls were collected in the same geographic regions and they matched with patients in age and gender. A total of five SNPs, two in the JAK1 gene: rs2780815 and rs310241 and the other three in the TNFAIP3: rs10499194, rs9494885 and rs610604, were included in this study. The genotyping of these SNPs was performed using a real time PCR system (TaqMan® SNP Genotyping Assays). RESULTS: No statistically significant differences were found when the patient and control groups were compared. The distribution of the risk alleles was similar in patients with and without eye manifestations and in patients with and without HLA-B*51. CONCLUSIONS: The association of variants of the genes JAK1 and the TNFAIP3 with BD which has been described in the Chinese population was not replicated in Europeans.

[Rituximab for treatment of patients with systemic autoimmune diseases]. / Utilidad del rituximab en el tratamiento de pacientes con enfermedades sistémicas autoinmunitarias.

BACKGROUND AND OBJECTIVE: To assess the value of rituximab in systemic autoimmune diseases which are refractory to others treatments. PATIENTS AND METHOD: Prospective study on 12 patients -7 with systemic lupus erythematosus (SLE), 4 with Wegener's granulomatosis (WG), and 1 with overlapping connective disease and autoimmune thrombocytopenia-, controlled in a specialized unit of a tertiary hospital. Four weekly doses of rituximab, 2 biweekly doses of cyclophosphamide, and glucocorticoids were administered to all patients, and other immunosuppressants were also administered as considered necessary in each case. RESULTS: Mean follow up after treatment with rituximab was 12.8 moths for SLE patients and 12.3 for WG patients. In SLE patients, proteinuria was reduced below 1 g daily in 5 cases (83%), with a clear parallel improvement in the urinary sediment. Serositis was resolved in both cases. One patient required 3 treatment cycles to obtain an adequate response and another required a second cycle for relapse. Only one patient with WG had a favorable response. The patient treated for autoimmune thrombocytopenia had a favorable response, with no relapses, and creatine-kinase levels also tended to return to normal. There were 2 serious adverse events (terminal renal failure and serious colitis in a patient with SLE, and death of one patient with WG), that were not adjudicated directly to rituximab. Immunoglobulin levels did not change substantially. There were no infusion reactions or associated infections. CONCLUSIONS: Rituximab was useful in patients with SLE refractory to other immunosuppressants. On the contrary, its efficacy in WG was limited. The response of thrombocytopenia was complete and maintained.