Toward Precision Medicine in Atopic Dermatitis Using Molecular-Based Approaches.

Atopic dermatitis is the most common chronic inflammatory skin disorder, affecting up to 20% of children and 10% of adults in developed countries. The pathophysiology of atopic dermatitis is complex and involves a strong genetic predisposition and T-cell driven inflammation. Although our understanding of the pathology and drivers of this disease has improved in recent years, there are still knowledge gaps in the immune pathways involved. Therefore, advances in new omics technologies in atopic dermatitis will play a key role in understanding the pathogenesis of this burden disease and could develop preventive strategies and personalized treatment strategies. In this review, we discuss the latest developments in genetics, transcriptomics, epigenomics, proteomics, and metagenomics and understand how integrating multiple omics datasets will identify potential biomarkers and uncover nets of associations between several molecular levels.

Toward Precision Medicine in Atopic Dermatitis Using Molecular-Based Approaches. / [Artículo traducido] Hacia una medicina de precisión en la dermatitis atópica mediante el uso de enfoques moleculares.

Atopic dermatitis is the most common chronic inflammatory skin disorder, affecting up to 20% of children and 10% of adults in developed countries. The pathophysiology of atopic dermatitis is complex and involves a strong genetic predisposition and T-cell driven inflammation. Although our understanding of the pathology and drivers of this disease has improved in recent years, there are still knowledge gaps in the immune pathways involved. Therefore, advances in new omics technologies in atopic dermatitis will play a key role in understanding the pathogenesis of this burden disease and could develop preventive strategies and personalized treatment strategies. In this review, we discuss the latest developments in genetics, transcriptomics, epigenomics, proteomics, and metagenomics and understand how integrating multiple omics datasets will identify potential biomarkers and uncover nets of associations between several molecular levels.

Predictors of fatigue and persistent fatigue in early rheumatoid arthritis: a longitudinal observational study, data from the ESPOIR cohort.

OBJECTIVE: To determine, in a cohort of patients with early rheumatoid arthritis (RA), factors associated with fatigue at baseline, describe its evolution over 5 years of follow-up, and determine baseline predictors of persistent fatigue. METHOD: We selected patients fulfilling the 2010 American College of Rheumatology/European League Against Rheumatism criteria for RA included in the ESPOIR cohort. Using bivariable and multivariable logistic regression models, we examined baseline variables associated with baseline fatigue (defined by visual analogue scale fatigue > 20) and baseline predictors of persistent fatigue (if the patient experienced fatigue at all visits during the 5 year follow-up period). RESULTS: We analysed 673 patients; 80.7% reported fatigue at baseline. At baseline, fatigue was associated with female gender, younger age, greater severity of morning stiffness, sleep problems, higher Health Assessment Questionnaire levels, presence of sicca symptoms, history of thyroid problems, and presence of psychological distress (depressive or anxiety symptoms). At 5 years of follow-up, the percentage of fatigued patients who reported fatigue at all time-points since baseline was 24.6% (referred to as 'persistent fatigue'). Independent baseline predictors were presence of sicca symptoms, greater severity of morning stiffness, and psychological distress. CONCLUSIONS: Fatigue is a frequent symptom in RA. The presence of sicca symptoms, greater severity of morning stiffness, and presence of psychological distress at baseline were associated with baseline fatigue and persistent fatigue at 5 years. We did not observe any association between baseline fatigue or persistent fatigue and the Disease Activity Score based on 28-joint count-erythrocyte sedimentation rate.

A genome-wide association study identifies a new locus associated with the response to anti-TNF therapy in rheumatoid arthritis.

Anti-Tumor Necrosis Factor (anti-TNF) drugs are biologic agents commonly used to treat rheumatoid arthritis (RA). However, anti-TNFs are not effective in approximately one out of four treated patients. We conducted a Genome-Wide Association Study (GWAS) to identify the genetic variation associated with the response to anti-TNF therapy in RA. In the discovery stage, 372 RA patients treated with an anti-TNF agent (infliximab, adalimumab or etanercept) were analyzed and treatment response was defined at 12 weeks of therapy. We found a genome-wide significant association in the MED15 gene with the response to etanercept (P<1.5e-8). Using an independent cohort of 245 RA patients, we performed a replication study of the most significant GWAS associations. We replicated the association at the MED15 locus and found suggestive evidence of association in the previously associated MAFB locus. The results of this study suggest novel mechanisms associated with the response to anti-TNF therapies.

Association of the PDE3A-SLCO1C1 locus with the response to anti-TNF agents in psoriasis.

Psoriasis is a prevalent autoimmune disease of the skin that causes significant psychological and physical disability. Tumor necrosis factor (TNF)-blocking agents have proven to be highly efficacious in the management of moderate-to-severe psoriasis. However, a significant percentage of patients do not respond to this treatment. Recently, variation at the PDE3A-SLCO1C1 (phosphodiesterase 3A-SoLute Carrier Organic anion transporter family member 1C1) locus has been robustly associated with anti-TNF response in rheumatoid arthritis. Using a cohort of 130 psoriasis patients treated with anti-TNF therapy, we sought to analyze the association of this locus with treatment response in psoriasis. We found a highly significant association between PDE3A-SLCO1C1 and the clinical response to TNF blockers (P=0.0031). Importantly, the allele that was previously associated with the lack of response to rheumatoid arthritis (G allele, single-nucleotide polymorphism rs3794271) was associated with a higher anti-TNF efficacy in psoriasis. The results of this study are an important step in the characterization of the pharmacogenetic profile associated with anti-TNF response in psoriasis.

The pathogenesis and genetics of psoriasis.

Psoriasis vulgaris and psoriatic arthritis are interrelated disorders with an important genetic component. While linkage studies have identified several candidate loci and genes, only recent technological advances and extensive genome-wide association studies have provided robust evidence of associations between psoriasis and several genes inside and outside the major histocompatibility complex. Most of these genes can be incorporated into an integrated pathogenic model of psoriatic disease comprising distinct signaling networks affecting skin barrier function (LCE3, DEFB4, GJB2), innate immune responses involving nuclear factor-κB signaling (TNFAIP3, TNIP1, NFKBIA, REL, FBXL19, TYK2, NOS2, CARD14), and adaptive immune responses involving CD8 T cells and interleukin 23 (IL-23)/IL-17-mediated lymphocyte signaling (HLA-C, IL12B, IL23R, IL23A, TRAF3IP2, ERAP1). A better understanding of the potential gene/gene and gene/environment interactions and of the functions of altered transcripts will undoubtedly have nosologic, therapeutic and prognostic implications.

Functional characterization of ATAD2 as a new cancer/testis factor and a predictor of poor prognosis in breast and lung cancers.

Cancer cells frequently express genes normally active in male germ cells. ATAD2 is one of them encoding a conserved factor harbouring an AAA type ATPase domain and a bromodomain. We show here that ATAD2 is highly expressed in testis as well as in many cancers of different origins and that its high expression is a strong predictor of rapid mortality in lung and breast cancers. These observations suggest that ATAD2 acts on upstream and basic cellular processes to enhance oncogenesis in a variety of unrelated cell types. Accordingly, our functional studies show that ATAD2 controls chromatin dynamics, genome transcriptional activities and apoptotic cell response. We could also highlight some of the important intrinsic properties of its two regulatory domains, including a functional cross-talk between the AAA ATPase domain and the bromodomain. Altogether, these data indicate that ATAD2 overexpression in somatic cells, by acting on basic properties of chromatin, may contribute to malignant transformation.

Clinical significance of synovial lymphoid neogenesis and its reversal after anti-tumour necrosis factor alpha therapy in rheumatoid arthritis.

OBJECTIVE: To investigate the clinical significance of lymphoid neogenesis (LN) in rheumatoid arthritis (RA), the clinicopathological correlates of this process and its evolution after anti-tumour necrosis factor (TNF)alpha therapy in a large series of synovial tissues were analysed. METHODS: Arthroscopic synovial biopsies from 86 patients with RA were analysed by immunohistochemistry. LN was defined as the presence of large aggregates of lymphocytes with T/B cell compartmentalisation and peripheral node addressin (PNAd) positive high endothelial venules. Clinical variables at baseline and after prospective follow-up were compared in LN positive and negative RA subsets. The evolution of LN and its correlation with the clinical course in a subgroup of 24 patients that underwent a second arthroscopic biopsy after anti-TNFalpha therapy was also analysed. RESULTS: LN was present in 49% of RA synovial tissues. Patients with LN had a significantly higher disease duration and a higher previous use of anti-TNFalpha agents. During prospective follow-up, the proportion of patients achieving good or moderate European League Against Rheumatism (EULAR) 28-joint Disease Activity Score (DAS28) responses was significantly lower in patients who were LN positive despite a significantly higher use of anti-TNFalpha agents. By multivariate logistic regression analysis, LN remained as an independent negative predictor of response to therapy. In the subgroup of patients rebiopsied after anti-TNFalpha therapy, reversal of LN features occurred in 56% of the patients and correlated with good clinical responses. CONCLUSIONS: Synovial LN in RA predicts a lower response to therapy. LN features can be reversed after a short period of anti-TNFalpha therapy in parallel to good clinical responses.

Adsorptive granulocyte/monocyte apheresis for the treatment of refractory rheumatoid arthritis: an open pilot multicentre trial.

OBJECTIVE: To assess the efficacy and safety of adsorptive granulocyte and monocyte apheresis (GCAP) in patients with refractory rheumatoid arthritis (RA). METHODS: Patients with active and refractory RA were treated with weekly GCAP sessions using a column filled with acetate beads (Adacolumn) over five consecutive weeks. Clinical assessments and response to therapy were analysed at weeks 5, 7, 12 and 20 in an open multicentre trial. The primary outcome measure of clinical response was 20% improvement in the American College of Rheumatology criteria (ACR20) at week 20. EULAR (European League Against Rheumatism) response criteria, based on the disease activity score for 28 joints (DAS28) and disability using the Health Assessment Questionnaire (HAQ), were also assessed. RESULTS: Of 27 patients, 81.5% were women with mean disease duration of 14.4 yr. The mean number of previous disease-modifying antirheumatic drugs (DMARDs) was 3.7, and 48.1% of patients had previously failed on biologicals. On an intention-to-treat basis, 40.7% of patients achieved an ACR20 and 44.4% a therapeutic EULAR response at week 20. These percentages were 50 and 54.5% in 22 patients who completed the trial. In the 10 completers who had previously failed on biologicals, an ACR response was achieved in four patients (ACR20, two; ACR50, one; ACR70, one). A significant decrease was recorded in different ACR response components, including the tender joint and swollen joint counts, pain score and patient and physician global disease assessments, as well as the DAS28 index; most of them improved after week 5. ESR and CRP, but not the HAQ score, had decreased significantly at week 20. The treatment was well tolerated and only one serious adverse event related to the study procedure was documented (sepsis due to a catheter infection). CONCLUSIONS: GCAP treatment led to significant clinical improvement in a subset of patients with RA who had failed to respond to DMARDs or biologicals. Further large, placebo-controlled studies are warranted to fully assess the therapeutic value of GCAP for refractory RA.

Predicting oxygen transfer of fine bubble diffused aeration systems--model issued from dimensional analysis.

The standard oxygenation performances of fine bubble diffused aeration systems in clean water, measured in 12 cylindrical tanks (water depth from 2.4 to 6.1m), were analysed using dimensional analysis. A relationship was established to estimate the scale-up factor for oxygen transfer, the transfer number (N(T)) The transfer number, which is written as a function of the oxygen transfer coefficient (k(L)a(20)), the gas superficial velocity (U(G)), the kinematic viscosity of water (nu) and the acceleration due to gravity (g), has the same physical meaning as the specific oxygen transfer efficiency. N(T) only depends on the geometry of the tank/aeration system [the total surface of the perforated membrane (S(p)), the surface of the tank (S) or its diameter (D), the total surface of the zones covered by the diffusers ("aerated area", S(a)) and the submergence of the diffusers (h)]. This analysis allowed to better describe the mass transfer in cylindrical tanks. Within the range of the parameters considered, the oxygen transfer coefficient (k(L)a(20)) is an increasing linear function of the air flow rate. For a given air flow rate and a given tank surface area, k(L)a(20) decreases with the water depth (submergence of the diffusers). For a given water depth, k(L)a(20) increases with the number of diffusers, and, for an equal number of diffusers, with the total area of the zones covered by the diffusers. The latter result evidences the superiority of the total floor coverage over an arrangement whereby the diffusers are placed on separate grids. The specific standard oxygen transfer efficiency is independent of the air flow rate and the water depth, the drop in the k(L)a(20) being offset by the increase of the saturation concentration. For a given tank area, the impact of the total surface of the perforated membrane (S(p)) and of the aerated area (S(a)) is the same as on the oxygen transfer coefficient.

Association study between corticotrophin-releasing hormone genomic region (8q13) and rheumatoid arthritis in the Spanish population.

OBJECTIVE: To investigate whether the corticotrophin-releasing hormone (CRH) genomic region confers genetic susceptibility to rheumatoid arthritis (RA) in the Spanish population. METHODS: DNA was obtained from 121 simplex RA families and 101 healthy controls, all from Spanish origin. Two microsatellites, CRHRA1 and CRHRA2, located 25 and 20 kb downstream respectively from the CRH gene were examined using a new multiplex design. Linkage disequilibrium (LD) between the markers was assessed and association studies were carried out using the transmission disequilibrium test (TDT) implemented in TRANSMIT. RESULTS: Both markers are in Hardy-Weinberg equilibrium and there is significant LD between them in the Spanish population. Neither the polymorphic alleles of CRHRA1 and CRHRA2 markers nor their resulting haplotypes were significantly associated to RA. The associated haplotype in the UK population (CRHRA1*10; CRHRA2*14) was undertransmitted in RA patients (12 obs vs 17.43 exp), although the difference is not statistically significant (P > 0.05). CONCLUSIONS: This is the first follow-up study of the association between the CRH genomic region and RA and suggests that the CRH gene may not be involved in the pathogenesis of RA in the Spanish population. Further studies in other populations will help untangle the real contribution of this genomic region to the susceptibility to RA.

Two different beta3 cysteine substitutions alter alphaIIb beta3 maturation and result in Glanzmann thrombasthenia.

We report the defects responsible for Glanzmann thrombasthenia in two patients showing traces of abnormally migrating platelet beta3 in immunoblotting. Using PCR-SSCP and direct sequencing, we identified a novel homozygous mutation in exon 10 of the beta3 gene of patient 1 which gave a C457 to Y amino acid substitution. A C542 to R substitution in beta3 of patient 2 was previously reported by us. These cysteines are present in EGF-domains 1 and 3 respectively of beta3. We therefore constructed mutants carrying substitutions on cysteine residues in each of the first three EGF domains of beta3, C457, C495 and C542 respectively. Transient expression of these mutants in COS-7 cells, including the C542 and C547 double mutant, proved that disulfide disruption directly affects cell surface expression of the integrin. We then showed by metabolic (35S) labeling and Endo-H glycosidase treatment that these substitutions strongly affected complex maturation within the cell.

Clinical, radiographic and HLA associations as markers for different patterns of psoriatic arthritis.

OBJECTIVE: The aim of this study was to examine whether the five clinical forms of psoriatic arthritis (PsA) identified by Moll and Wright (Semin Arthritis Rheum 1973;3:55-78) could be clearly distinguished, especially as the disease evolved over time, to analyse whether radiographic features or HLA associations could define subsets with greater precision and to identify predictors of disease outcome. METHODS: Seventy-three patients (37 males and 36 females) were followed for a median time of 8 yr (range 1-16 yr). A standard clinical protocol was used to assess patients at each visit and two clinical scores. based on the joint areas involved, were defined to evaluate the mode of onset and the evolution of arthritis. X-ray films of the hands, feet and sacroiliac joints were taken and the patients were divided into two categories according to the presence or absence of erosions and an X-ray erosion score was also used. Three classification methods were used to define the different clinical subsets. HLA-A, B and DR antigens were tested by standard microlymphocytotoxicity assays. A multiple linear regression model was used in the statistical analysis. RESULTS: The five classical clinical subsets defined by Moll and Wright did not remain since distinct peripheral arthritis patterns tended to evolve over time. Only two discrete groups were identified, axial disease (AD) (sacroilitis with or without peripheral arthritis) in 29% of cases and peripheral disease (PD) without sacroilitis in 71%. AD was positively associated with the duration of arthritis (P < 0.04), presence of mutilation (P < 0.02) and the joint area score over disease evolution (JASE) (P < 0.02). There were erosions in 71% of the patients. Erosions correlated with the presence of mutilation (P < 0.007) and with the JASE (P < 0.0005). HLA-B27 was found in 43% of patients with AD, but only in 11% of PD patients (P < 0.01). No other clear HLA correlations were found. CONCLUSIONS: Despite the relatively small number of patients, this longitudinal study suggests that only two clinical subsets can be clearly defined in PsA, AD and PD; these are primarily determined on clinical grounds although HLA-B27 is strongly associated with AD. The evolution of PD pattern with time means that narrower peripheral arthritis subsets are of little clinical use.

Behçet's disease and pregnancy relationship study.

The effects of pregnancy on the course of Behçet's disease (BD), and vice versa, are unknown and little has been reported. We have studied three groups of women: (1) group A included 61 pregnancies in 23 women with BD, 25 pregnancies took place in 10 patients already diagnosed (group 1A) and 36 pregnancies occurred in 13 patients before disease diagnosis (group 2A); (2) group B included 30 females with 83 pregnancies affected by recurrent oral ulcers (ROU); (3) group C included 20 healthy women with 61 pregnancies. We investigated the effects of BD on pregnancy and fetal outcome, and the influence of gestation on the course of BD. A questionnaire was used in which specific information about each pregnancy, labour and puerperium was collected. We looked for medical confirmation in all cases where any pathology had been identified. No significant differences were found in the incidence of pregnancy complications between groups. The incidence of perinatal death was also similar and neither congenital abnormalities nor neonatal BD were observed. Only two patients observed a flare of the disease and in two cases the diagnosis of BD was made during the pregnancy. In our series, the outcome of pregnancy was generally good in BD patients, disease manifestations were not consistently worsened and fetal outcome was excellent. The first case of Budd-Chiari syndrome during the puerperium in a BD patient is reported.

Association of TAP2 polymorphism with rheumatoid arthritis is secondary to allelic association with HLA-DRB1.

OBJECTIVE: To study polymorphisms of the newly described TAP2 locus in rheumatoid arthritis (RA) and to analyze their relationship with HLA-DRB1 alleles previously implicated in the development of the disease. METHODS: TAP2 polymorphic residues at 3 sites, Val/Ile-379, Ala/Thr-565, and Ala/Thr-665, were characterized by amplification refractory mutation system polymerase chain reaction in 185 RA patients and 48 HLA-DR4 positive healthy controls. HLA-DR4 subtypes were determined by sequence-specific priming and oligonucleotide hybridization. RESULTS: The frequencies of Ile-379, Thr-565, and Thr-665 were significantly increased in DR4 positive versus DR4 negative RA patients. TAP2 genotype distributions also differed between the patient groups stratified by DR4 status. However, no significant differences in TAP2 polymorphisms were observed between DR4 positive RA patients and DR4 positive controls, although relationships between specific DR4 subtypes and TAP2 variants were identified. CONCLUSION: Particular TAP2 polymorphisms are associated with distinct HLA-DR specificities in both normal and RA populations. Thus, the prevalence of specific TAP2 residues and genotypes in RA appears to be secondary to the HLA-DR frequencies and genotypic combinations that are typical of RA.