CD73 and CD29 concurrently mediate the mechanically induced decrease of migratory capacity of mesenchymal stromal cells

e assumption that mesenchymal stromal cell (MSC)-based-therapies are capable of augmenting physiological regeneration processes has fostered intensive basic and clinical research activities. However, to achieve sustained therapeutic success in vivo, not only the biological, but also the mechanical microenvironment of MSCs during these regeneration processes needs to be taken into account. This is especially important for e.g., bone fracture repair, since MSCs present at the fracture site undergo significant biomechanical stimulation. This study has therefore investigated cellular characteristics and the functional behaviour of MSCs in response to mechanical loading. Our results demonstrated a reduced expression of MSC surface markers CD73 (ecto-5'-nucleotidase) and CD29 (integrin β1) after loading. On the functional level, loading led to a reduced migration of MSCs. Both effects persisted for a week after the removal of the loading stimulus. Specific inhibition of CD73/CD29 demonstrated their substrate dependent involvement in MSC migration after loading. These results were supported by scanning electron microscopy images and phalloidin staining of actin filaments displaying less cell spreading, lamellipodia formation and actin accumulations. Moreover, focal adhesion kinase and Src-family kinases were identified as candidate downstream targets of CD73/CD29 that might contribute to the mechanically induced decrease in MSC migration. These results suggest that MSC migration is controlled by CD73/CD29, which in turn are regulated by mechanical stimulation of cells. We therefore speculate that MSCs migrate into the fracture site, become mechanically entrapped, and thereby accumulate to fulfil their regenerative functions.

Induced apoptosis of chondrocytes by Porphyromonas gingivalis as a possible pathway for cartilage loss in rheumatoid arthritis

The role of bacterial infections in the pathogenesis of rheumatoid arthritis (RA) has gained increasing interest. Patients with RA often exhibit periodontal disease, which is associated with pathogens like Porphyromonas gingivalis. The present study examines the direct effects of P. gingivalis on apoptosis of human chondrocytes (a feature of inflammatory joint diseases) as one can assume an interrelation of pathogenesis of RA and P. gingivalis infections. Primary chondrocytes were infected with P. gingivalis. Early apoptotic and dead cell analysis was performed using Annexin-V, 7AAD, and propidium iodide and examined by flow cytometry and fluorescence microscopy. Caspase activation and DNA fragmentation were determined by western blot analysis and TUNEL reaction. Flow cytometry and fluorescence microscopy demonstrated an increase of Annexin-V-positive early apoptotic chondrocytes after infection. Western blot showed upregulation of activated caspase-3 expression, and TUNEL reaction revealed considerable DNA fragmentation following infection. The data show that P. gingivalis promotes early and later stages of apoptosis of primary human chondrocytes, which might contribute to the joint damage seen in the pathogenesis of RA.

Methotrexate treatment in large vessel vasculitis and polymyalgia rheumatica

In large vessel vasculitis, including giant cell arteritis and Takayasu arteritis, as well as in polymyalgia rheumatica, glucocorticoid therapy is the treatment of choice. However, there are two situations/questions for additional immunosuppressive therapies in these diseases: (i) therapy resistance to glucocorticoid mono-therapy; (ii) situations which call for sparing of glucocorticoids such as in complications of glucocorticoid therapy. This review summarises the current scientific debate on the effects of methotrexate in these diseases. Methotrexate at 10-15 mg/week appears to have a modest and delayed effect in GCA and PMR in reducing relapse rate and lowering the cumulative dose of glucocorticoid therapy. However, superiority of combination therapy in reducing the incidence of glucocorticoid-related complications has not been shown yet. The effects of higher doses and long-time effects as well as the efficacy in patients with glucocorticoid-resistance and complications are unclear. Methotrexate may thus be considered as adjunctive therapy to glucocorticoid therapy in glucocorticoid-resistance or complications. Further attempts should be made for a better identification of patients with glucocorticoid-refractory courses and a more precise formulation of guidelines on indication, optimal dosing and duration.

Monitoring adverse events of low-dose glucocorticoid therapy: EULAR recommendations for clinical trials and daily practice

Objective

To develop recommendations on monitoring for adverse events (AEs) of low-dose glucocorticoid (GC) therapy (≤7.5 mg prednisone or equivalent daily) in clinical trials and daily practice.

Methods

Literature was searched for articles containing information on incidence and monitoring of GC-related AEs using PubMed, EMBASE and Cochrane databases. Second, the authors searched for broad accepted guidelines on the monitoring of certain AEs (eg, WHO guidelines on screening for diabetes). Available data were summarised and discussed among experts (rheumatologists and patients) of the EULAR Task Force to decide which potential AEs should be monitored, how and at which interval.

Results

Data on monitoring proved to be scarce; most articles were focused on therapeutic effects of GCs, not on occurrence and monitoring of AEs. Most recommendations had to be based on consensus. Those for clinical trials aimed at getting insights into incidence, prevalence and clinical relevance of AEs to create a comprehensive and valid AE-profile of GC therapy. The set of AEs to monitor is therefore more extensive, and often consists of assessments at baseline and at end of trials. Recommendations for daily practice are meant to protect patients from real dangers, which can be prevented or treated. Standard care monitoring needs NOT be extended for patients on low-dose GC therapy, except for osteoporosis (follow national guidelines), and baseline assessments of ankle edema, fasting blood glucose and risk factors for glaucoma.

Conclusion

Given the incompleteness of literature data, consensus-based recommendations on monitoring for GC-related AEs were created, separately for daily practice and clinical trials.

Energy regulation and neuroendocrine-immune control in chronic inflammatory diseases

Energy regulation (EnR) is most important for homoeostatic regulation of physiological processes. Neuroendocrine pathways are involved in EnR. We can separate factors that provide energy-rich fuels to stores [parasympathetic nervous system (PSNS), insulin, insulin-like growth factor-1, oestrogens, androgens and osteocalcin] and those that provide energy-rich substrates to consumers [sympathetic nervous system (SNS), hypothalamic-pituitary-adrenal axis, thyroid hormones, glucagon and growth hormone]. In chronic inflammatory diseases (CIDs), balanced energy-rich fuel allocation to stores and consumers, normally aligned with circadian rhythms, is largely disturbed due to the vast fuel consumption of an activated immune system (up to 2000 kJ day(-1)). Proinflammatory cytokines such as tumour necrosis factor or interleukins 1beta and 6, circulating activated immune cells and sensory nerve fibres signal immune activation to the rest of the body. This signal is an appeal for energy-rich fuels as regulators are switched on to supply energy-rich fuels ('energy appeal reaction'). During evolution, adequate EnR evolved to cope with nonlife-threatening diseases, not with CIDs (huge negative selection pressure and reduced reproduction). Thus, EnR is inadequate in CIDs leading to many abnormalities, including sickness behaviour, anorexia, hypovitaminosis D, cachexia, cachectic obesity, insulin resistance, hyperinsulinaemia, dyslipidaemia, fat deposits near inflamed tissue, hypoandrogenaemia, mild hypercortisolaemia, activation of the SNS (hypertension), CID-related anaemia and osteopenia. Many of these conditions can contribute to the metabolic syndrome. These signs and symptoms become comprehensible in the context of an exaggerated call for energy-rich fuels by the immune system. We propose that the presented pathophysiological framework may lead to new therapeutical approaches and to a better understanding of CID sequence.

[Pathogenesis of parodontitis in rheumatic diseases]

Inflammatory periodontal disease (PD) is a common disease worldwide that has a primarily bacterial aetiology and is characterized by dysregulation of the host inflammatory response. The degree of inflammation varies among individuals with PD independently of the degree of bacterial infection, suggesting that alteration of the immune function may substantially contribute to its extent. Factors such as smoking, education, and body mass index (BMI) are discussed as potential risk factors for PD. Most PD patients respond to bacterial invaders by mobilizing their defensive cells and releasing cytokines such as interleukin (IL)-1beta, tumour necrosis factor (TNF)-alpha, and IL-6, which ultimately causes tissue destruction by stimulating the production of collagenolytic enzymes, such matrix metalloproteinases. Recently, there has been growing evidence suggesting an association between PD and the increased risk of systemic diseases, such ateriosclerosis, diabetes mellitus, stroke, and rheumatoid arthritis (RA). PD and rheumatologic diseases such as RA share many pathological aspects and immunological findings.

[Bone densitometry in inflammatory rheumatic diseases : Characteristics of the measurement site and disease-specific factors]

Bone densitometry should be performed earlier in patients with inflammatory arthritis, since factors such as inflammation and drug therapy, in particular treatment with glucocorticoids, have an important impact on the development of osteoporosis. DXA (Dual energy X-ray Absorptiometry) is considered the gold standard for bone densitometry. According to the German guidelines for osteoporosis, bone densitometry plays a crucial role in the choice of therapy.In patients with rheumatoid arthritis, measurement of peripheral bone (forearm) density in addition to lumbar spine and hip is recommended, since local bone loss is pathognomonic for this disease. DXA measurements of the hand enable the diagnosis of juxtaarticular osteoporosis at an earlier stage; however, this has not yet been established in routine practise.Bone measurement in patients with ankylosing spondylitis can be performed in the lumbar spine and the hip at disease onset. In systemic lupus erythematosus, bone loss is more frequent in patients with high inflammatory activity. Patients with psoriasis arthritis frequently have osteoporosis in the case of a destructive development of the joints.

Effects of hypoxia and/or lack of glucose on cellular energy metabolism and cytokine production in stimulated human CD4+ T lymphocytes

Oxidative phosphorylation and/or glycolysis provide energy, mainly in the form of ATP, which ensures proper functioning of immune cells such as CD4(+) T lymphocytes. However, the main substrates, namely oxygen and glucose, are known to remain for a relatively short time in the inflamed tissue and in other clinical situations where immune cells need to function properly. Therefore, we examined the effect of hypoxia and/or lack of glucose on cellular energy metabolism and on cytokine secretion in stimulated human CD4(+) T lymphocytes. Human CD4(+) T cells were MACS-isolated using peripheral blood obtained from healthy donors. Stimulated cells were incubated in medium with or without glucose for 6h in a sealed chamber which led to cumulative hypoxia. During this incubation period, (i) oxygen saturation was measured continuously using a Clark-type electrode, and (ii) samples were taken at different time points in order to quantify for each the viability of cells, intracellular reactive oxygen species (iROS), ATP levels, glycolytic enzyme activity, mRNA expression of hexokinase-1 and superoxide dismutase-1, and concentrations of several different cytokines. Stimulated CD4(+) T cells which were incubated under normoxic conditions served as controls. Under hypoxic conditions, lack of glucose exerted a biphasic effect on cellular oxygen consumption: initially higher but later lower respiration rates were measured when compared to conditions where glucose was available. Lack of glucose strongly increased the number of dead cells and the formation of iROS under normoxia but not under hypoxia. Under both normoxic and hypoxic conditions, intracellular ATP levels remained almost unchanged during the incubation period if glucose was present, but decreased significantly in the absence of glucose, despite the enhanced glycolytic enzyme activity. Measurements of stimulated cytokine production demonstrated (i) that cumulative hypoxia stimulates especially the secretion of IL-1beta, IL-10 and IL-8, and (ii) that lack of glucose results in lower cytokine concentrations. We demonstrate that CD4(+) T cells are highly adaptive in bioenergetic terms which ensure their proper function under extreme conditions of glucose and/or oxygen availability as found under physiological and pathophysiological conditions. Hypoxia seems to facilitate inflammatory reactions and angiogenesis.

Periodontal disease in patients with ankylosing spondylitis

OBJECTIVE

Ankylosing spondylitis (AS) and periodontal disease (PD) are characterised by dysregulation of the host inflammatory response, resulting in soft and hard connective tissue destruction. AS has been related to other inflammatory diseases, however, there is a paucity of data on whether AS is associated with inflammatory PD.

METHODS

The association between AS and PD was examined in 48 patients with AS and 48 healthy controls, matched for age and gender. AS was diagnosed according to the modified New York criteria. Periodontal examination included probing pocket depth (PPD), clinical attachment loss (CAL), plaque index (PI) and bleeding on probing (BOP). Potential risk factors of PD such as smoking, low education, alcohol consumption, body mass index (BMI), as well as chronic diseases associated with PD and AS were assessed through questionnaires.

RESULTS

In stepwise logistic regression, including AS status, age, gender, education, smoking, alcohol consumption and BMI, only AS status, age and education remained significant predictors of PD. Patients with AS had significant 6.81-fold increased odds (95% CI 1.96 to 23.67) of PD (defined as mean attachment loss >3 mm) compared to controls. The strength of the association was attenuated but remained statistically significant after further adjustment for plaque accumulation (odds ratio (OR) 5.48, 95% CI 1.37 to 22.00).

CONCLUSIONS

The present study shows that patients with AS have a significantly higher risk of PD, strongly suggesting the need for close collaboration between rheumatologists, periodontists and dental hygienists when treating patients with AS.

Patient and rheumatologist perspectives on glucocorticoids: an exercise to improve the implementation of the European League Against Rheumatism (EULAR) recommendations on the management of systemic glucocorticoid therapy in rheumatic diseases

OBJECTIVE

To explore perspectives among patients and rheumatologists on glucocorticoid (GC) therapy and European League Against Rheumatism (EULAR) recommendations on the management of systemic GC therapy in order to enhance implementation of the recommendations.

METHODS

Rheumatologists (from eight countries) and patients (from five countries) acquainted with GCs participated in separate meetings, during which positive and negative aspects of GC therapy were discussed and possible adverse events (AEs) were ranked for importance; in addition participants were asked to evaluate the published EULAR recommendations. The reports from these meetings and themes related to implementation of the recommendations were discussed during an international forum of the experts who had formulated the recommendations and patient participants.

RESULTS

In all, 140 patients (78% women; mean age 53 years; 61% patients with rheumatoid arthritis) and 110 rheumatologists (mean work experience 15 years) participated in the meetings. Osteoporosis, diabetes and cardiovascular diseases were ranked among the five most worrisome AEs by patients and rheumatologists. In both groups, there was agreement with most of the recommendations; the recommendations on GC information cards and GC use during pregnancy scored lowest. Ideas to improve implementation of the recommendations and a research agenda were generated.

CONCLUSION

The patient and rheumatologist views on GCs corresponded to a large extent, reflected by concerns in both groups about osteoporosis, diabetes and cardiovascular diseases. Specific problems with the EULAR recommendations were identified and addressed to improve their implementation. This exercise shows that patient and rheumatologist perspectives should be included early in the process of formulating recommendations.

Analyses of similarities and differences in glucocorticoid therapy between rheumatoid arthritis and ankylosing spondylitis - a systematic comparison

Glucocorticoids (GCs) have powerful and potent anti-inflammatory and immunomodulatory effects and are widely established in regard to the treatment of rheumatism and other diseases. In rheumatoid arthritis (RA), GCs are used systemically at several different dosages and/or local (intraarticular) therapy. They have been shown to exert strong short-term anti-inflammatory effects but also long-term positive effects on radiographic progression of the disease. In comparison, patients with ankylosing spondylitis (AS) are considered to be less responsive to GC therapy than patients with RA, although controlled studies on the effects of low-dose GCs in AS are lacking. In AS, GCs are mainly used for local therapy and occasionally for systemic pulse therapy only. The underlying mechanisms for these differences are unclear. GCs act on primary and secondary immune cells via different mechanisms of action: cytosolic GC receptor (cGCR)-mediated genomic and non-genomic effects, membrane-bound GC receptor (mGCR)-mediated non-genomic effects and - as achieved at very high concentrations - non-specific non-genomic effects. The phenomenon of GC resistance is also known in RA. Several different mechanisms may mediate this phenomenon; among them are alterations in number, binding affinity or phosphorylation status of the GCR, polymorphic changes and/or over-expression of chaperones/ co-chaperones, increased expression of inflammatory transcription factors, the multidrug resistance pump, over-expression of the GCR beta isoform, alteration in the expression of mGCR and imbalance of 11beta-hydroxysteroid dehydrogenase type 1 & 2 activity. Translation of insights on GC action and resistance obtained in RA to AS may contribute to a better understanding of the pathophysiology of both diseases.

Effects of celecoxib on the expression of osteoprotegerin, energy metabolism and cell viability in cultured human osteoblastic cells

BACKGROUND AND OBJECTIVE

The selective COX-2 inhibitor celecoxib is widely used to treat pain and inflammation in rheumatoid arthritis, osteoarthritis, and ankylosing spondylitis. The drug has well-known important effects on immune cells but its direct and/or indirect influence on osteoblasts has not yet been explored in detail. This study aimed to investigate the dose-dependent effects of celecoxib on cell viability, energy metabolism and bone remodeling processes in cultured human osteoblastic cells.

METHODS

Primary human osteoblasts and MG-63 cells were incubated with celecoxib (2, 10, 50microM). Cell viability and apoptosis were determined by trypan blue, 7AAD and Annexin-V staining. Effects on cellular oxygen consumption were measured amperometrically using a Clark electrode. mRNA expression of GLUT-1 and OPG was determined by RT-PCR; OPG protein secretion by ELISA and HIF-1alpha protein expression by immunoblotting.

RESULTS

While celecoxib at a concentration of 2 and 10microM showed only marginal effects, a suprapharmacological concentration of 50microM influenced viability and energy metabolism, as well as OPG expression and secretion of osteoblastic cells. Cell viability was significantly reduced by celecoxib treatment. Celecoxib at 50microM stimulated oxygen consumption significantly. Corresponding experiments with the protonophore FCCP suggest that this effect is due to mitochondrial uncoupling. After 24h, GLUT-1 mRNA expression was significantly increased. HIF-1alpha protein was not expressed under any of our experimental conditions. We also showed that celecoxib at 50microM significantly inhibits OPG protein secretion leading to a compensative increase of mRNA expression.

CONCLUSION

Pronounced effects of celecoxib on cell viability (reduction), oxygen consumption (stimulation), GLUT-1 mRNA expression (stimulation) and OPG protein secretion (inhibition) in osteoblastic cells were observed only at 50microM-a concentration not reached by therapeutic doses giving plasma concentrations less than 10microM. On the contrary, celecoxib at 2 and 10microM showed only marginal effects, suggesting that celecoxib administration is probably safe with respect to bone metabolism in cases requiring potent treatment of pain and inflammation. However, higher intracellular concentrations, which might occur through accumulation, necessitate investigations with high concentrations.

Effects of Porphyromonas gingivalis on cell cycle progression and apoptosis of primary human chondrocytes

BACKGROUND

It has been suggested that bacterial infections have a role in the pathogenesis of rheumatoid arthritis (RA). P gingivalis, a Gram-negative, anaerobic rod, is one of the major pathogens associated with periodontal disease.

OBJECTIVE

To examine P gingivalis infection and its effects on cell cycle progression and apoptosis of human articular chondrocytes.

METHODS

Primary human chondrocytes cultured in monolayers were challenged with P gingivalis. Infection and invasion of P gingivalis into chondrocytes was analysed by scanning electron microscopy, double immunofluorescence and by antibiotic protection and invasion assay. Cell cycle progression of infected chondrocytes was evaluated by flow cytometry. Also, cell apoptosis was visualised by terminal deoxynucleotidyl transferase-mediated dUTP nick end labelling (TUNEL) of DNA strand breaks and by western blot analysis.

RESULTS

Data showed that P gingivalis could adhere and infect primary human chondrocytes. After chondrocyte infection, intracellular localisation of P gingivalis was noted. Flow cytometry analyses demonstrated affected cell cycle progression, with an increase of the G(1) phase and a significant decrease of the G(2) phase after infection. In addition, increased apoptosis of P gingivalis-infected chondrocytes was visualised by TUNEL assay and by upregulation of caspase-3 protein expression.

CONCLUSION

These data demonstrate that P gingivalis infects primary human chondrocytes and affects cellular responses, which might contribute to the tissue damage seen in the pathogenesis of rheumatoid arthritis.

[Glucocorticoids in rheumatology]

Glucocorticoids (GC) are effective drugs which are often used in rheumatology. However, they have a considerable potential for frequent and sometimes serious side effects that restrict their use. Their mechanisms of action are either receptor dependent (specific) or independent (unspecific) on the genomic as well as the non-genomic level. Many adverse effects are predominantly caused by transactivation while the desired effects are mostly mediated by transrepression. Treatment strategies are sub-classified into low, medium, high, very high dose and pulse therapy based on criteria such as dose, indication, duration of treatment and potential risk of adverse events. The musculoskeletal, gastrointestinal, neuro-endocrino-immunological, opthalmological and neuropsychiatric systems are examples where adverse effects may occur.

[Influence of adjuvant pain medication on quality of life in the treatment of postmenopausal osteoporosis]

AIM OF THE STUDY

Chronic pain is the main symptom of postmenopausal osteoporosis. This can decrease mobility and quality of life of the patients. The hypothesis of this study was that administration of an adjuvant pain medication is essential additionally to the basic therapy. The second question was if a recommendation can be formulated whether a peripheral or a central acting pain medication is more effective to prevent osteoporosis induced chronic pain.

METHODS

Three pseudorandomised patient groups were prospectively compared. Group 1 was treated with alendronate, vitamin D, and calcium. Group 2 also received ibuprofen, and group 3 also received tramadol. In 117 women suffering from postmenopausal osteoporosis, quality of life was measured before and 26 weeks after therapy using the International Osteoporosis Foundation Qualeffo-41 score, and pain intensity was measured using a visual analogue scale.

RESULTS

No therapy-associated complications were observed during the study. After 26 weeks, quality of life significantly increased in groups 2 and 3 compared with group 1 (p<0.001). Pain intensity decreased in group 1 by only 6 points, whereas it decreased in group 2 by 31 points and in group 3 by 24 points. Pain relief was significantly different between the treatment groups and the control group and between the treatment groups themselves (p<0.001 and p<0.01).

CONCLUSION

We conclude that pain therapy with an almost peripherally acting drug such as ibuprofen can reduce osteoporosis-associated chronic pain better than a centrally acting pain medication such as tramadol. It therefore can be recommended to prescribe ibuprofen rather than tramadol for treating osteoporosis-associated chronic pain in postmenopausal women if the specific risk for gastrointestinal side effects is considered.

Association among rheumatoid arthritis, oral hygiene, and periodontitis

BACKGROUND

A limited number of studies suggest a higher prevalence of periodontal disease among individuals with rheumatoid arthritis (RA); however, results have been inconsistent. Further, it is unclear to what extent poor oral hygiene among patients with RA may account for this association.

METHODS

The association between RA and periodontitis was examined in 57 subjects with RA and 52 healthy controls, matched by age and gender. Oral examination included plaque index (PI), gingival index (GI), probing depth (PD), and clinical attachment loss (CAL). Potential risk factors for periodontal disease, such as smoking, education, alcohol consumption, and body mass index (BMI), as well as chronic diseases associated with RA and periodontal disease were assessed through questionnaires.

RESULTS

In a stepwise logistic regression, including RA status, age, gender, education, smoking, alcohol consumption, and BMI, only RA status and age remained significant predictors of periodontal disease. Subjects with RA had a significant 8.05-fold increased odds (95% confidence interval: 2.93 to 22.09) of periodontitis compared to controls. The strength of the association was attenuated but remained statistically significant after further adjustment for PI, GI, or both. PI alone accounted for 12.4%, GI alone accounted for 11.1%, and PI and GI combined accounted for 13.4% of the association between RA and periodontitis.

CONCLUSIONS

Subjects with RA have significantly increased periodontal attachment loss compared to controls. Oral hygiene may only partially account for this association.

Dose-related patterns of glucocorticoid-induced side effects

OBJECTIVE

To identify patterns of self-reported health problems relating to dose and duration of glucocorticoid intake in unselected patients with rheumatoid arthritis from routine practice.

METHODS

Data from 1066 patients were analysed. The clinical status and drug treatment were reported by the physician, health problems during the past 6 months by the patient using a comprehensive list of symptoms. Patients with ongoing glucocorticoid treatment for more than 6 months and current doses of less than 5, 5-7.5 and over 7.5 mg/day prednisone equivalent were compared with a group without any glucocorticoid treatment for at least 12 months.

RESULTS

The frequency of self-reported health problems was lowest in the group without glucocorticoid exposition and increased with dosage. Two distinct dose-related patterns of adverse events were observed. A "linear" rising with increasing dose was found for cushingoid phenotype, ecchymosis, leg oedema, mycosis, parchment-like skin, shortness of breath and sleep disturbance. A "threshold pattern" describing an elevated frequency of events beyond a certain threshold value was observed at dosages of over 7.5 mg/day for glaucoma, depression/listlessness and increase in blood pressure. Dosages of 5 mg/day or more were associated with epistaxis and weight gain. A very low threshold was seen for eye cataract (<5 mg/day).

CONCLUSION

The associations found are in agreement with biological mechanisms and clinical observations. As there is a paucity of real-life data on adverse effects of glucocorticoids prescribed to unselected groups of patients, these data may help the clinician to adapt therapy with glucocorticoids accordingly and improve the benefit-risk ratio.