Profibrotic Effects of Endothelin-1 on Fibroblasts Are Mediated by Aldosterone in Vitro: Relevance to the Pathogenesis and Therapy of Systemic Sclerosis and Pulmonary Arterial Hypertension.

Endothelin-1 (ET-1) is a vasoactive and profibrotic peptide that plays a pivotal role in diseases such as systemic sclerosis (SSc) and pulmonary arterial hypertension (PAH), by inducing fibrosis and vascular remodeling. Such effects may be sustained by the induction of aldosterone production and reactive oxygen species (ROS). We have used fibroblasts obtained from skin of healthy donors and SSc patients and commercial fibroblasts from lung to evaluate whether ET-1 is able to stimulate ROS production directly or indirectly through aldosterone induction. We found that ET-1 receptors are present in all types of fibroblasts analyzed, whereas the expression of mineralocorticoid receptor (MCR) is lower in dermal fibroblasts from healthy donors (HDFs) compared to fibroblasts derived from lung (HPFs) or from skin of SSc patients (SScHDFs). ET-1 induces ROS production in HDFs and SScHDFs after 24 h of incubation involving its receptor B (ETB), whereas aldosterone exerts its effects after 40 min of incubation. Moreover, ROS production was inhibited by the pre-incubation of cells with MCR inhibitor. Our results indicate that ET-1 induces ROS indirectly through aldosterone production suggesting that aldosterone may play a pivotal role in the pathogenesis of SSc and PAH.

Instruments for Outcome Evaluation of Specific Domains in Primary Sjögren's Syndrome.

Primary Sjögren's syndrome (pSS) is a systemic autoimmune disorder characterized by very heterogeneous features. The spectrum of this disorder may vary from benign but disabling symptoms such as dryness, due to lachrymal and salivary involvement, pain and fatigue, to systemic, potentially severe, manifestations that may involve any organ. In recent decades, the arrival of biotechnological therapy has offered new opportunities for the treatment of this-until now-orphan disease. Currently, the possible use of these new drugs in therapeutic trials has made it necessary to have reliable outcome measures to evaluate their efficacy in this disease. A great effort has been made in multicenter, often multinational, studies to develop and validate instruments capable of assessing the different disease-related features. The adoption in therapeutic trials of the newly developed outcome measures aimed at assessing systemic features and patient reported symptoms has often yielded disappointing results. These negative data have been ascribed, on the one hand, to the trial design not being completely appropriate, and, on the other hand, to the fact that a single instrument may be not sufficient to cover the great clinical heterogeneity of the disease features. There is now growing belief that composite end points that include instruments that are able to assess the various aspects of the disease may be more properly and successfully used in future therapeutic trials.

Management of Sjögren's Syndrome: Present Issues and Future Perspectives.

In view of the new possibilities for the treatment of primary Sjögren's syndrome (pSS) given by the availability of new biotechnological agents targeting the various molecular and cellular actors of the pathological process of the disease, classification criteria aimed at selecting patients to be enrolled in therapeutic trials, and validated outcome measures to be used as response criteria to these new therapies, have been developed and validated in the last decades. Unfortunately, the therapeutic trials so far completed with these new treatments have yielded unsatisfactory or only partially positive results. The main issues that have been evoked to justify the poor results of the new therapeutic attempts are: (i) the extreme variability of the disease phenotypes of the patients enrolled in the trials, which are dependent on different underlying patterns of biological mechanisms, (ii) the fact that the disease has a long indolent course, and that most of the enrolled patients might already have irreversible clinical features. The advances in the research of new disease biomarkers that can better distinguish the different clinical phenotypes of patients and diagnose the disease in an earlier phase are also discussed.

Therapeutic Recommendations for the Management of Older Adult Patients with Sjögren's Syndrome.

Primary Sjögren's syndrome (SjS) is a systemic autoimmune disease most commonly diagnosed in middle-aged women. Although the disease can occur at all ages, it is diagnosed between 30 and 60 years of age in two-thirds of patients. In more than 20% of cases, the people are older than 65 years. In this review, we focus on the therapeutic management of primary SjS in older patients, following the recently published 2020 European League Against Rheumatism (EULAR) recommendations for the management of the disease with topical and systemic therapies. These recommendations are applicable to all patients with primary SjS regardless of age at diagnosis, although the therapeutic management in older patients requires additional considerations. Older patients are more likely to have pulmonary, liver, kidney, or heart-related comorbidities (even cognitive disturbances); caution is required when most drugs are used, including muscarinic agents, systemic corticosteroids and synthetic immunosuppressants. It is also important to monitor the use of eye drops containing steroids due to the increased risk of developing cataracts, a frequent ocular complication in the older population. In contrast, the majority of drugs that can be used topically (pilocarpine rinses, eye drops containing topical non-steroidal anti-inflammatory drugs (NSAIDs) or cyclosporine A, topical dermal formulations of NSAIDs) have shown an acceptable safety profile in older patients, as well as rituximab. A rigorous evaluation of the medical history of older patients is essential when drugs included in the EULAR guidelines are prescribed, with special attention to factors frequently related to ageing, such as polypharmacy, the existence of organ-specific comorbidities, or the enhanced susceptibility to infections.

The Role of Interferons in the Pathogenesis of Sjögren's Syndrome and Future Therapeutic Perspectives.

There is a great deal of evidence pointing to interferons (IFNs) as being key cytokines in the pathogenesis of different systemic autoimmune diseases, including primary Sjögren's syndrome (pSS). In this disease, a large number of studies have shown that an overexpression of type I IFN, the 'so-called' type I IFN signature, is present in peripheral blood mononuclear cells, and that this finding is associated with the development of systemic extra-glandular manifestations, and a substantial production of autoantibodies and inflammatory cytokines. In contrast, the absence or a milder expression of type I IFN signature and low level of inflammatory cytokines characterizes patients with a different clinical phenotype, where the disease is limited to glandular involvement and often marked by the presence of widespread pain and depression. The role of type II (IFNγ) in this subset of pSS patients, together with the potentially related activation of completely different immunological and metabolic pathways, are emerging issues. Expression of both types of IFNs has also been shown in target tissues, namely in minor salivary glands where a predominance of type II IFN signature appeared to have a certain association with the development of lymphoma. In view of the role played by IFN overexpression in the development and progression of pSS, inhibition or modulation of IFN signaling has been regarded as a potential target for the therapeutic approach. A number of therapeutic compounds with variable mechanisms of action have been tested or are under consideration for the treatment of patients with pSS.

Impact of COVID-19 outbreak in an Italian cohort of patients with systemic sclerosis.

BACKGROUND: Mortality rate in patients infected by severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) can be related to the presence of comorbidities like diabetes, cardiovascular and pulmonary diseases. On the contrary, few data exist on the impact of CoronaVirus Disease 2019 (COVID-19) on patients with rheumatic disorders, namely in those having pulmonary involvement and treated with immunosuppressive agents. The present survey is aimed at knowing the impact of COVID-19 in a cohort of patients with systemic sclerosis (SSc). METHODS: Telephone interviews were carried out during the COVID-19 outbreak in patients with SSc followed in a Rheumatic Disease Unit in Italy. Patients were asked for confirmed SARS-CoV-2 infection, symptoms suggestive of COVID-19, and modification of their therapy. RESULTS: A total number of 526 patients with SSc were contacted and interviewed. Of them, 270 and 256 had limited cutaneous and diffuse cutaneous SSc, respectively. Interstitial lung disease (ILD) was present in 45% of patients and most of them (68.2%) were treated with immunosuppressive therapy. Only two patients were hospitalized for COVID-19-related pneumonia, and one of them died despite invasive ventilator support. An additional 11 patients reported flu-like symptoms compatible with a mild form of COVID-19. Nobody modified the therapy during the COVID-19 outbreak. CONCLUSION: Despite the large prevalence of ILD and immunosuppressive therapies, which can be considered risk factors for the occurrence and severity of incidental viral infections, the impact of COVID-19, in terms of mortality rate and morbidity, does not appear particularly severe in this large cohort of patients with SSc. Possible mechanisms influencing this figure are discussed.

High NEMO score values in nailfold videocapillaroscopy are associated with the subsequent development of ischaemic digital ulcers in patients with systemic sclerosis.

BACKGROUND: Nailfold videocapillaroscopy (NVC) is a feasible method that allows the observation of the microvascular changes that mark the course of systemic sclerosis (SSc). In previous studies, we demonstrated that the NEMO score, i.e. the cumulative number of microhaemorrhages and microthromboses, is a good indicator of the steady-state level and overtime changes of disease activity (DA) in SSc. OBJECTIVES: To verify whether high NEMO scores, which mirror a very active microvascular derangement in the fingers, may be associated with the subsequent development of ischaemic digital ulcers (IDUs). METHODS: The NEMO score was assessed at baseline (T0) in 98 patients with SSc, all classified according to the ACR-EULAR criteria. Of them, 90 were females, 48 had the limited and 50 had the diffuse cutaneous variant of SSc. Afterwards, the patients were closely followed up for 2 years, and the appearance of new IDUs recorded at any time of the follow-up. The T0-NEMO score values of patients who developed IDUs were compared to those of patients who did not. A receiver operating curve (ROC) was constructed, and the area under the curve (AUC) calculated by plotting the sensitivity and 1-specificity of the different NEMO score values in predicting the subsequent development of IDUs. RESULTS: During the follow-up, 38 out of 98 patients developed one or more IDUs. The NEMO score at T0 was significantly higher in those who developed IDUs with respect to those who did not [median 14.5 (95% CI 11.0-21.5) and 4.5 (95% CI 4.0-6.0), respectively, p < 0.0001]. The ROC curve derived from different T0-NEMO score values had an AUC of 0.79 (95% CI 0.69-0.86, p < 0.0001). A NEMO score of ≥ 12 had a sensitivity of 83.3% (95% CI 71.5-91.7) and a specificity of 63.2% (95% CI 46.0-78.2), with positive (P) and negative (N) predictive (PV) values of 58.9% (95% CI 44.7-72.2) and 85.6% (71.8-94.4), respectively. A NEMO score of ≥ 16 had a sensitivity of 95.0% (95% CI 86.1-99.0) and a NPV of 93.4% (77.5-99.2). CONCLUSIONS: Being a valid tool to measure DA levels in SSc, the NEMO score also appears to be closely related to the subsequent development of IDUs in this disease.

EULAR recommendations for the management of Sjögren's syndrome with topical and systemic therapies.

The therapeutic management of Sjögren syndrome (SjS) has not changed substantially in recent decades: treatment decisions remain challenging in clinical practice, without a specific therapeutic target beyond the relief of symptoms as the most important goal. In view of this scenario, the European League Against Rheumatism (EULAR) promoted and supported an international collaborative study (EULAR SS Task Force) aimed at developing the first EULAR evidence and consensus-based recommendations for the management of patients with SjS with topical and systemic medications. The aim was to develop a rational therapeutic approach to SjS patients useful for healthcare professionals, physicians undergoing specialist training, medical students, the pharmaceutical industry and drug regulatory organisations following the 2014 EULAR standardised operating procedures. The Task Force (TF) included specialists in rheumatology, internal medicine, oral health, ophthalmology, gynaecology, dermatology and epidemiology, statisticians, general practitioners, nurses and patient representatives from 30 countries of the 5 continents. Evidence was collected from studies including primary SjS patients fulfilling the 2002/2016 criteria; when no evidence was available, evidence from studies including associated SjS or patients fulfilling previous sets of criteria was considered and extrapolated. The TF endorsed the presentation of general principles for the management of patients with SjS as three overarching, general consensus-based recommendations and 12 specific recommendations that form a logical sequence, starting with the management of the central triplet of symptoms (dryness, fatigue and pain) followed by the management of systemic disease. The recommendations address the use of topical oral (saliva substitutes) and ocular (artificial tear drops, topical non-steroidal anti-inflammatory drugs, topical corticosteroids, topical CyA, serum tear drops) therapies, oral muscarinic agonists (pilocarpine, cevimeline), hydroxychloroquine, oral glucocorticoids, synthetic immunosuppressive agents (cyclophosphamide, azathioprine, methotrexate, leflunomide and mycophenolate), and biological therapies (rituximab, abatacept and belimumab). For each recommendation, levels of evidence (mostly modest) and TF agreement (mostly very high) are provided. The 2019 EULAR recommendations are based on the evidence collected in the last 16 years in the management of primary 2002 SjS patients and on discussions between a large and broadly international TF. The recommendations synthesise current thinking on SjS treatment in a set of overarching principles and recommendations. We hope that the current recommendations will be broadly applied in clinical practice and/or serve as a template for national societies to develop local recommendations.

NEMO score in nailfold videocapillaroscopy is a good tool to assess both steady state levels and overtime changes of disease activity in patients with systemic sclerosis: a comparison with the proposed composite indices for this disease status entity.

BACKGROUND: In previous studies, we demonstrated that the NEMO score, i.e. the cumulative number of microhaemorrhages (MHEs) and microthromboses (MTs), observed in nailfold videocapillaroscopy was a good indicator of the steady state level of disease activity (DA) in patients with systemic sclerosis (SSc) when the European Scleroderma Study Group (EScSG) index was considered the gold standard. AIM OF THE STUDY: To verify whether the NEMO score could be (i) a valid tool to assess DA, even when the modified European Scleroderma Trials and Research (EUSTAR) index was considered to be the comparator, and (ii) a sensitive method to capture the DA overtime changes. PATIENTS AND METHODS: The NEMO score and the EScSG and EUSTAR indices were contemporarily assessed at baseline (T0) and after a follow-up of 4-56 months (T1) in 98 patients with SSc. The differences (Δ) between the T1 and T0 values of the NEMO score and the EScSG and EUSTAR indices were calculated and compared to each other. RESULTS: NEMO score values were very closely correlated with the corresponding values of the EScSG and EUSTAR indices both at T0 and T1 observations (p < 0.0001 in all cases with the exception of the correlation with EScSG values at T1 (p < 0.03)). The values of the two composite DA indices were also strictly related to each other in both T0 and T1 observations (p < 0.0001). Receiver operating characteristic (ROC) curve analysis showed the NEMO score had a good sensitivity and specificity in classifying patients with a predefined level of DA (scores ≥ 3.0 and ≥ 2.5 for the EScSG and EUSTAR indices, respectively, p < 0.0001 in both cases). Δ values of the NEMO score were significantly correlated with the corresponding values of both the EScSG and EUSTAR indices. Weighted Cohen's k level of agreement between Δ values of the NEMO score and those of the EScSG and EUSTAR indices was moderate (0.55 and 0.59, respectively). CONCLUSIONS: NEMO score proves to be a feasible, non-invasive, and valid tool to assess steady state levels and changes over time of DA in patients with SSc. Thus, it can represent an alternative or complementary method to measure this disease status entity in this disorder.

Gene Expression Profiles in Primary Sjögren's Syndrome With and Without Systemic Manifestations.

OBJECTIVE: To investigate the gene expression profile in patients with Sjögren's syndrome that is characterized by different clinical phenotypes. METHODS: RNA from peripheral blood mononuclear cells was purified in 8 patients with glandular features (GFs) and widespread pain (WP) and 11 with extraglandular manifestations (EGMs) and then was analyzed by hybridization on a human gene chip exploring more than 40,000 human genes. Differentially expressed genes (DEGs) in the two subgroups (ie, those with false discovery rate-corrected P values ≤ 0.01) with respect to 20 healthy controls have been submitted to functional classification using a Gene Ontology database and were mapped to define the networks of protein to protein interactions (PPIs). RESULTS: The enriched pathway analyses of DEGs and of the highly interconnected modules identified in the PPI networks showed that the pathological processes characterizing the two subgroups were substantially different. The predominant pathways in patients with EGMs are related to T- and B-cell activation, Toll-like receptor, interferon signaling, and apoptosis. Conversely, pathological processes related to pain transmission and modulation are preferentially operative in patients with GFs and WP. These data suggest that a neuroinflammatory pathway driven by cytokines and chemokines may play a central role in triggering WP features in this phenotype of patients. CONCLUSION: The present study supports the hypothesis that different biological pathways are operative in patients with primary Sjögren's syndrome with different clinical phenotypes. A better knowledge of these specific processes might help in tailoring more effective target therapies.

Efficacy and safety of topical and systemic medications: a systematic literature review informing the EULAR recommendations for the management of Sjögren's syndrome.

Objective: To evaluate current evidence on the efficacy and safety of topical and systemic medications in patients with primary Sjögren syndrome (SjS) to inform European League Against Rheumatism treatment recommendations. Methods: The MEDLINE, EMBASE and Cochrane databases were searched for case-control/prospective cohort studies, randomised controlled trials (RCTs) and systematic reviews. Results: Current evidence in primary SjS patients fulfilling the 2002 criteria is based on the data from 9 RCTs, 18 prospective cohort studies and 5 case-control studies. Two Cochrane systematic literature reviews (SLRs) have reported that topical treatments for dry mouth and dry eye are safe and effective. Ocular cyclosporine A was safe and effective in two RCTs including 1039 patients with dry eye syndrome. Two Cochrane SLRs on serum tear drops and plugs showed inconsistency in possible benefits, both for symptoms and objective measures. Five RCTs reported significant improvements in oral dryness and salivary flow rates for pilocarpine and cevimeline. An RCT showed no significant placebo-differences for hydroxychloroquine 400 mg/day for the primary outcome (visual analogue scale (VAS) composite of dryness, fatigue and pain). We identified seven RCTs carried out in primary SjS patients. RCTs using infliximab, anakinra and baminercept found no placebo-differences for the primary outcomes. The two largest RCTs randomised 255 patients to receive rituximab or placebo and reported no significant results in the primary outcome (VAS composite), while prospective studies suggested efficacy in systemic disease. Conclusion: The current evidence supporting the use of the main topical therapeutic options of primary SjS is solid, while limited data from RCTs are available to guide systemic therapies.

Long Non-Coding RNAs Modulate Sjögren's Syndrome Associated Gene Expression and Are Involved in the Pathogenesis of the Disease.

Primary Sjögren's syndrome (pSjS) is a chronic systemic autoimmune disorder, primarily affecting exocrine glands; its pathogenesis is still unclear. Long non-coding RNAs (lncRNAs) are thought to play a role in the pathogenesis of autoimmune diseases and a comprehensive analysis of lncRNAs expression in pSjS is still lacking. To this aim, the expression of more than 540,000 human transcripts, including those ascribed to more than 50,000 lncRNAs is profiled at the same time, in a cohort of 16 peripheral blood mononuclear cells PBMCs samples (eight pSjS and eight healthy subjects). A complex network analysis is carried out on the global set of molecular interactions among modulated genes and lncRNAs, leading to the identification of reliable lncRNA-miRNA-gene functional interactions. Taking this approach, a few lncRNAs are identified as targeting highly connected genes in the pSjS transcriptome, since they have a major impact on gene modulation in the disease. Such genes are involved in biological processes and molecular pathways crucial in the pathogenesis of pSjS, including immune response, B cell development and function, inflammation, apoptosis, type I and gamma interferon, epithelial cell adhesion and polarization. The identification of deregulated lncRNAs that modulate genes involved in the typical features of the disease provides insight in disease pathogenesis and opens avenues for the design of novel therapeutic strategies.

Regional grafting of autologous adipose tissue is effective in inducing prompt healing of indolent digital ulcers in patients with systemic sclerosis: results of a monocentric randomized controlled study.

BACKGROUND: A randomized controlled trial (RCT) was performed to confirm preliminary uncontrolled data indicating that regional adipose tissue (AT) grafting (G) is effective in inducing ischemic digital ulcer (IDU) healing in patients with systemic sclerosis (SSc). PATIENTS AND METHODS: SSc patients with IDUs were randomized to be blindly treated with AT-G or a sham procedure (SP). AT-G consisted of injection, at the base of the finger with the IDU, of 0.5-1 ml AT after centrifugation of fat aspirate. The SP consisted of false liposuction and local injection of saline solution. The primary endpoint was to compare the cumulative prevalence of healed IDUs in the two groups within the following 8 weeks. RESULTS: AT-G and the SP were carried out in 25 and 13 patients, respectively. The two groups were comparable for age, gender, disease duration, and SSc subtypes. IDU healing was observed in 23/25 and 1/13 patients treated with AT-G and the SP, respectively (p < 0.0001). The 12 patients who received the unsuccessful SP underwent a rescue AT-G. In all of them, IDU healing was observed after 8 weeks of observation. It was noticeable that in the AT-G-treated patients a significant reduction of pain intensity (measured by visual analogue scale) was recorded after 4 and 8 weeks (p < 0.0001 in all cases). Similarly, a significant increase of capillary numbers in the affected finger was recorded by nailfold videocapillaroscopy after 4 and 8 weeks (p < 0.0001 in both cases). CONCLUSION: This RCT strongly confirms that AT-G is effective in inducing IDU healing in SSc patients. TRIAL REGISTRATION: ClinicalTrials.gov, NCT03406988 . Registered retrospectively on 25 January 2018.

Guidelines for biomarkers in autoimmune rheumatic diseases - evidence based analysis.

Autoimmune rheumatic diseases are characterised by an abnormal immune system response, complement activation, cytokines dysregulation and inflammation. In last years, despite many progresses in managing these patients, it has been shown that clinical remission is reached in less than 50% of patients and a personalised and tailored therapeutic approach is still lacking resulting in a significant gap between guidelines and real-world practice. In this context, the need for biomarkers facilitating early diagnosis and profiling those individuals at the highest risk for a poor outcome has become of crucial interest. A biomarker generally refers to a measured characteristic which may be used as an indicator of some biological state or condition. Three different types of medical biomarkers has been suggested: i. mechanistic markers; ii. clinical disease markers; iii. therapeutic markers. A combination of biomarkers from these different groups could be used for an ideal more accurate diagnosis and treatment. However, although a growing body of evidence is focused on improving biomarkers, a significant amount of this information is not integrated on standard clinical care. The overarching aim of this work was to clarify the meaning of specific biomarkers during autoimmune diseases; their possible role in confirming diagnosis, predicting outcome and suggesting specific treatments.

Apical vertebral derotation and translation (AVDT) for adolescent idiopathic scoliosis using screws and sublaminar bands: a safer concept for deformity correction.

PURPOSE: To assess the efficacy and safety of a new deformity correction philosophy treatment for AIS called apical vertebral derotation and translation (AVDT). METHODS: It is a retrospective study of prospectively collected data concerning two different scoliosis correction techniques used in our department. A total of 81 patients (22M, 59F) with a mean age of 15.5 years and minimum follow-up of 2 years were reviewed. Patients were divided into two groups according to the correction technique: 36 patients underwent single-rod derotation using all screws construct (AS), while 45 patients underwent apical vertebral derotation and translation using screws and sublaminar bands (SB). RESULTS: The mean improvement of the MT curve was 70% in the AS group and 60.6% in the SB group, while the mean improvement of the TL/L curve was 65.5 and 72.4%, respectively. PT increased in both groups after surgery with a mean amount of 2.5° in the AS group and only 1° in the SB group. We observed also a greater amount of cervical lordosis reduction in the AS group (4.5°) compared with the SB group (only 1°). The SB group had less operative time and less blood loss. CONCLUSION: There was no significant difference between the two groups at the final follow-up and both techniques led to an excellent correction in the frontal plane; in the sagittal plane, the AVDT technique seemed to give less sagittal imbalance with better cervical profile; the surgical procedure is easy with less operative time, less blood loss and less risk of potential complications. These slides can be retrieved under Electronic Supplementary Material.

Management of primary Sjögren's syndrome: recent developments and new classification criteria.

For many years primary Sjögren's syndrome (pSS) has been considered an orphan disease, since no specific therapies were recognized as being capable of contrasting the development and progression of this disorder. The treatment of oral and ocular features, as well as of the systemic organ involvement, has been entrusted to the joint management of different subspecialty physicians, like ophthalmologists, otolaryngologists, dentists and rheumatologists. These latter subspecialty doctors are usually more involved in the treatment of systemic extraglandular involvement and, to do it, they have long been using the conventional therapies borrowed by the treatment schedules adopted in other systemic autoimmune diseases. The increasing knowledge of the biological pathways that are operative in patients with pSS, and the parallel development of molecular biology technology, have allowed the production and availability of a number of biological agents able to positively act on different disease mechanisms, and thus are candidates for testing in therapeutic trials. Meanwhile, the scientific community has made a great effort to develop new accurate and validated classification criteria and outcome measures to be applied in the selection of patients to be included and monitored in therapeutic studies. Some of the new-generation biotechnological agents have been tested in a number of open-label and randomized controlled trials that have produced in many cases inconclusive or contradictory results. Behind the differences in trial protocols, adopted outcome measures and predefined endpoints, reasons for such unsatisfactory results can be found in the large heterogeneity of clinical subtypes in the examined cohorts. The future challenge for a substantial advancement in the therapeutic approach to pSS could be to identify the pathologic mechanisms, outcome tools and biomarkers that characterize the different subsets of the disease in order to test carefully selected target therapies with the highest probability of success in each different clinical phenotype.