Best clinical practice in the treatment of juvenile systemic sclerosis: expert panel guidance - the result of the International Hamburg Consensus Meeting December 2022.

INTRODUCTION: Juvenile systemic sclerosis (jSSc) is an orphan disease with a prevalence of 3 in 1,000,000 children. Currently there is only one consensus treatment guideline concerning skin, pulmonary and vascular involvement for jSSc, the jSSc SHARE (Single Hub and Access point for pediatric Rheumatology in Europe) initiative, which was based on data procured up to 2014. Therefore, an update of these guidelines, with a more recent literature and expert experience, and extension of the guidance to more aspects of the disease is needed. AREAS COVERED: Treatment options were reviewed, and opinions were provided for most facets of jSSc including general management, some of which differs from adult systemic sclerosis, such as the use of corticosteroids, and specific organ involvement, such as skin, musculoskeletal, pulmonary, and gastroenterology. EXPERT OPINION: We are suggesting the treat to target strategy to treat early to prevent cumulative disease damage in jSSc. Conclusions are derived from both expert opinion and available literature, which is mostly based on adult systemic sclerosis (aSSc), given shared pathophysiology, extrapolation of results from aSSc studies was judged reasonable.

EULAR recommendations for the non-pharmacological management of systemic lupus erythematosus and systemic sclerosis.

OBJECTIVE: To develop evidence-based recommendations for the non-pharmacological management of systemic lupus erythematosus (SLE) and systemic sclerosis (SSc). METHODS: A task force comprising 7 rheumatologists, 15 other healthcare professionals and 3 patients was established. Following a systematic literature review performed to inform the recommendations, statements were formulated, discussed during online meetings and graded based on risk of bias assessment, level of evidence (LoE) and strength of recommendation (SoR; scale A-D, A comprising consistent LoE 1 studies, D comprising LoE 4 or inconsistent studies), following the European Alliance of Associations for Rheumatology standard operating procedure. Level of agreement (LoA; scale 0-10, 0 denoting complete disagreement, 10 denoting complete agreement) was determined for each statement through online voting. RESULTS: Four overarching principles and 12 recommendations were developed. These concerned common and disease-specific aspects of non-pharmacological management. SoR ranged from A to D. The mean LoA with the overarching principles and recommendations ranged from 8.4 to 9.7. Briefly, non-pharmacological management of SLE and SSc should be tailored, person-centred and participatory. It is not intended to preclude but rather complement pharmacotherapy. Patients should be offered education and support for physical exercise, smoking cessation and avoidance of cold exposure. Photoprotection and psychosocial interventions are important for SLE patients, while mouth and hand exercises are important in SSc. CONCLUSIONS: The recommendations will guide healthcare professionals and patients towards a holistic and personalised management of SLE and SSc. Research and educational agendas were developed to address needs towards a higher evidence level, enhancement of clinician-patient communication and improved outcomes.

Proposed Response Parameters for Twelve-Month Drug Trial in Juvenile Systemic Sclerosis: Results of the Hamburg International Consensus Meetings.

OBJECTIVE: Juvenile systemic sclerosis (SSc) is an orphan disease, associated with high morbidity and mortality. New treatment strategies are much needed, but clearly defining appropriate outcomes is necessary if successful therapies are to be developed. Our objective here was to propose such outcomes. METHODS: This proposal is the result of 4 face-to-face consensus meetings with a 27-member multidisciplinary team of pediatric rheumatologists, adult rheumatologists, dermatologists, pediatric cardiologists, pulmonologists, gastroenterologists, a statistician, and patients. Throughout the process, we reviewed the existing adult data in this field, the more limited pediatric literature for juvenile SSc outcomes, and data from 2 juvenile SSc patient cohorts to assist in making informed, data-driven decisions. The use of items for each domain as an outcome measure in an open label 12-month clinical trial of juvenile SSc was voted and agreed upon using a nominal group technique. RESULTS: After voting, the domains agreed on were global disease activity, skin, Raynaud's phenomenon, digital ulcers, musculoskeletal, cardiac, pulmonary, renal, and gastrointestinal involvement, and quality of life. Fourteen outcome measures had 100% agreement, 1 item had 91% agreement, and 1 item had 86% agreement. The domains of biomarkers and growth/development were moved to the research agenda. CONCLUSION: We reached consensus on multiple domains and items that should be assessed in an open label, 12-month clinical juvenile SSc trial as well as a research agenda for future development.

Patient Experience of Systemic Sclerosis-Related Calcinosis: An International Study Informing Clinical Trials, Practice, and the Development of the Mawdsley Calcinosis Questionnaire.

Systemic sclerosis (SSc) -related calcinosis can be a debilitating, constantly painful, poorly understood vascular complication of calcium hydroxyapatite deposition in soft tissue structures that affects approximately 40% of both limited and diffuse cutaneous SSc subtypes. This publication describes the iterative and multitiered international qualitative investigations that yielded remarkable insights into natural history, daily experience, and complications of SSc-calcinosis providing pivotal information for health management. Patient-driven question development and field testing, according to Food and Drug Administration guidance, propelled the development of a patient-reported outcome measure for SSc-calcinosis, the Mawdsley Calcinosis Questionnaire.

Management of systemic sclerosis: British Society for Rheumatology guideline scope.

This guideline will provide a practical roadmap for management of SSc that builds upon the previous treatment guideline to incorporate advances in evidence-based treatment and increased knowledge about assessment, classification and management. General approaches to management as well as treatment of specific complications will be covered, including lung, cardiac, renal and gastrointestinal tract disease, as well as RP, digital vasculopathy, skin manifestations, calcinosis and impact on quality of life. It will include guidance related to emerging approved therapies for interstitial lung disease and account for National Health Service England prescribing policies and national guidance relevant to SSc. The guideline will be developed using the methods and processes outlined in Creating Clinical Guidelines: Our Protocol. This development process to produce guidance, advice and recommendations for practice has National Institute for Health and Care Excellence accreditation.

A Phase II randomized controlled trial of oral prednisolone in early diffuse cutaneous systemic sclerosis (PRedSS).

OBJECTIVES: Although the painful and disabling features of early diffuse cutaneous SSc (dcSSc) have an inflammatory basis and could respond to corticosteroids, corticosteroids are a risk factor for scleroderma renal crisis. Whether or not they should be prescribed is therefore highly contentious. Our aim was to examine safety and efficacy of moderate-dose prednisolone in early dcSSc. METHODS: PRedSS set out as a Phase II, multicentre, double-blind randomized controlled trial, converted to open-label during the Covid-19 pandemic. Patients were randomized to receive either prednisolone (∼0.3 mg/kg) or matching placebo (or no treatment during open-label) for 6 months. Co-primary endpoints were the HAQ Disability Index (HAQ-DI) and modified Rodnan skin score (mRSS) at 3 months. Over 20 secondary endpoints included patient reported outcome measures reflecting pain, itch, fatigue, anxiety and depression, and helplessness. Target recruitment was 72 patients. RESULTS: Thirty-five patients were randomized (17 prednisolone, 18 placebo/control). The adjusted mean difference between treatment groups at 3 months in HAQ-DI score was -0.10 (97.5% CI: -0.29, 0.10), P = 0.254, and in mRSS -3.90 (97.5% CI: -8.83, 1.03), P = 0.070, both favouring prednisolone but not significantly. Patients in the prednisolone group experienced significantly less pain (P = 0.027), anxiety (P = 0.018) and helplessness (P = 0.040) than control patients at 3 months. There were no renal crises, but sample size was small. CONCLUSION: PRedSS was terminated early primarily due to the Covid-19 pandemic, and so was underpowered. Therefore, interpretation must be cautious and results considered inconclusive, indicating the need for a further randomized trial. TRIAL REGISTRATION: ClinicalTrials.gov, https://clinicaltrials.gov, NCT03708718.

World Health Organization (WHO) International Classification of Functioning, Disability and Health (ICF) Core Set Development for Interstitial Lung Disease.

Background: The World Health Organization (WHO) introduced the International Classification of Functioning, Disability, and Health (ICF) as a scientific method of disability data collection comprised of >1,200 categories describing the spectrum of impairment types (functional, symptoms-based and anatomical) under the bio-psycho-social model with consideration of environmental and personal factors (pf). ICF Core Sets and ICF Checklists are streamlined disease-specific resources for clinical use, service provision, and for use in health economics and health policy. ICF can disclose strengths and weaknesses across multiple patient-reported outcome measures (PROMs) and help consolidate best-fitting question-items from multiple PROMs. Interstitial lung diseases (ILDs), are generally progressive, with restrictive physiology sometimes occurring in the context of multi-organ autoimmunity/inflammatory conditions such as connective tissue diseases (CTDs). In spite of significant associated morbidity and potential disability, ILD has yet to be linked to the ICF. Methods: Each instrument and their question-items within the consensus-recommended core sets for clinical trials in ILD were deconstructed to single concept units, and then linked per updated ICF linkage rules. Inter-linker agreement was established. Three additional subsequently validated measures were also included. Results: One-hundred-eleven ICF categories were identified for ten PROMs and three traditional objective measures that were amenable to ICF linkage. The proportion of agreement ranged from 0.79 (95% CI: 0.62, 0.91) to 0.93 (0.76, 0.99) with the overall proportion of inter-linker agreement being very high 0.86 (0.82, 0.89) for the initial instruments, with 94-100% for the three additional PROMs. Thirty-four new 'Personal Factors' emerged to capture disease-specific qualities not elsewhere described in ICF, e.g. 'pf_embarrassed by cough' or 'pf_panic/afraid when can't get a breath'. Conclusion: This first known effort in ICF linkage of ILD has provided important revelations on the current utility of the ICF in lung disease. Results have indicated areas for meaningful assessment of ICF descriptors for lung impairment. The mapping across PROMs provides insight into possibilities of developing more streamline and precise instrumentation. Finally, familiarity with the ICF in ILD may enable clinicians to experience a smoother transition with the imminent harmonization of ICD and ICF, ICD-11.

Development and validation of a patient-reported outcome measure for systemic sclerosis: the EULAR Systemic Sclerosis Impact of Disease (ScleroID) questionnaire.

OBJECTIVES: Patient-reported outcome measures (PROMs) are important for clinical practice and research. Given the high unmet need, our aim was to develop a comprehensive PROM for systemic sclerosis (SSc), jointly with patient experts. METHODS: This European Alliance of Associations for Rheumatology (EULAR)-endorsed project involved 11 European SSc centres. Relevant health dimensions were chosen and prioritised by patients. The resulting Systemic Sclerosis Impact of Disease (ScleroID) questionnaire was subsequently weighted and validated by Outcome Measures in Rheumatology criteria in an observational cohort study, cross-sectionally and longitudinally. As comparators, SSc-Health Assessment Questionnaire (HAQ), EuroQol Five Dimensional (EQ-5D), Short Form-36 (SF-36) were included. RESULTS: Initially, 17 health dimensions were selected and prioritised. The top 10 health dimensions were selected for the ScleroID questionnaire. Importantly, Raynaud's phenomenon, impaired hand function, pain and fatigue had the highest patient-reported disease impact. The validation cohort study included 472 patients with a baseline visit, from which 109 had a test-retest reliability visit and 113 had a follow-up visit (85% female, 38% diffuse SSc, mean age 58 years, mean disease duration 9 years). The total ScleroID score showed strong Pearson correlation coefficients with comparators (SSc-HAQ, 0.73; Patient's global assessment, Visual Analogue Scale 0.77; HAQ-Disability Index, 0.62; SF-36 physical score, -0.62; each p<0.001). The internal consistency was strong: Cronbach's alpha was 0.87, similar to SSc-HAQ (0.88) and higher than EQ-5D (0.77). The ScleroID had excellent reliability and good sensitivity to change, superior to all comparators (intraclass correlation coefficient 0.84; standardised response mean 0.57). CONCLUSIONS: We have developed and validated the EULAR ScleroID, which is a novel, brief, disease-specific, patient-derived, disease impact PROM, suitable for research and clinical use in SSc.

A comprehensive framework for navigating patient care in systemic sclerosis: A global response to the need for improving the practice of diagnostic and preventive strategies in SSc.

Systemic sclerosis (SSc), the most lethal of rheumatologic conditions, is the cause of death in >50% of SSc cases, led by pulmonary fibrosis followed by pulmonary hypertension and then scleroderma renal crisis (SRC). Multiple other preventable and treatable SSc-related vascular, cardiac, gastrointestinal, nutritional and musculoskeletal complications can lead to disability and death. Vascular injury with subsequent inflammation transforming to irreversible fibrosis and permanent damage characterizes SSc. Organ involvement is often present early in the disease course of SSc, but requires careful history-taking and vigilance in screening to detect. Inflammation is potentially reversible provided that treatment intensity quells inflammation and other immune mechanisms. In any SSc phenotype, opportunities for early treatment are prone to be under-utilized, especially in slowly progressive phenotypes that, in contrast to severe progressive ILD, indolently accrue irreversible organ damage resulting in later-stage life-limiting complications such as pulmonary hypertension, cardiac involvement, and malnutrition. A single SSc patient visit often requires much more physician and staff time, organization, vigilance, and direct management for multiple organ systems compared to other rheumatic or pulmonary diseases. Efficiency and efficacy of comprehensive SSc care enlists trending of symptoms and bio-data. Financial sustainability of SSc care benefits from understanding insurance reimbursement and health system allocation policies for complex patients. Sharing care between recognised SSc centers and local cardiology/pulmonary/rheumatology/gastroenterology colleagues may prevent complications and poor outcomes, while providing support to local specialists. As scleroderma specialists, we offer a practical framework with tools to facilitate an optimal, comprehensive and sustainable approach to SSc care. Improved health outcomes in SSc relies upon recogntion, management and, to the extent possible, prevention of SSc and treatment-related complications.

Exercise as a multi-modal disease-modifying medicine in systemic sclerosis: An introduction by The Global Fellowship on Rehabilitation and Exercise in Systemic Sclerosis (G-FoRSS).

Systemic sclerosis (SSc) is a heterogeneous multisystem autoimmune disease whereby its main pathological drivers of disability and damage are vascular injury, inflammatory cell infiltration, and fibrosis. These mechanisms result in diffuse and diverse impairments arising from ischemic circulatory dysfunction leading to painful skin ulceration and calcinosis, neurovascular aberrations hindering gastrointestinal (GI) motility, progressive painful, incapacitating or immobilizing effects of inflammatory and fibrotic effects on the lungs, skin, articular and periarticular structures, and muscle. SSc-related impairments impede routine activities of daily living (ADLs) and disrupt three critical life areas: work, family, social/leisure, and also impact on psychological well-being. Physical activity and exercise are globally recommended; however, for connective tissue diseases, this guidance carries greater impact on inflammatory disease manifestations, recovery, and cardiovascular health. Exercise, through myogenic and vascular phenomena, naturally targets key pathogenic drivers by downregulating multiple inflammatory and fibrotic pathways in serum and tissue, while increasing circulation and vascular repair. G-FoRSS, The Global Fellowship on Rehabilitation and Exercise in Systemic Sclerosis recognizes the scientific basis of and advocates for education and research of exercise as a systemic and targeted SSc disease-modifying treatment. An overview of biophysiological mechanisms of physical activity and exercise are herein imparted for patients, clinicians, and researchers, and applied to SSc disease mechanisms, manifestations, and impairment. A preliminary guidance on exercise in SSc, a research agenda, and the current state of research and outcome measures are set forth.

Suitability for e-health of non-pharmacological interventions in connective tissue diseases: scoping review with a descriptive analysis.

OBJECTIVE: Non-pharmacological interventions support patients with connective tissue diseases to better cope with and self-manage their diseases. This study aimed to map existing evidence on non-pharmacological interventions in patients with systemic lupus erythematosus (SLE), systemic sclerosis (SSc) and mixed connective tissue diseases regarding content, feasibility and potential suitability in an e-health setting. METHODS: A literature search was performed in eight different databases in July 2020. The intervention's content was extracted using the 'Better reporting of interventions: template for intervention description and replication (TIDieR) checklist and guide'. A Sankey diagram and descriptive statistics were used to analyse the data and illustrate the relationships between the interventions. RESULTS: Of 8198 identified records, 119 papers were eligible. One hundred and four of them (87.4%) were conducted between 2000 and 2020, mainly in the USA (SLE n=24 (21.2%), SSc n=16 (14.2%)), Brazil (SLE n=8 (7.1%), SSc n=5 (4.4%)) and Italy (SLE n=0 (0%), SSc n=12 (10.6%)). Fifty-two studies (SLE n=24 (21.2%), SSc n=28 (24.8%)) used multicomponent interventions. The single interventions were physical exercises (SLE n=16 (14.2%), SSc n=17 (15.0%)), coaching/counselling (SLE n=11 (18.0%), SSc n=0 (0%)) and education (SLE n=2 (1.8%), SSc n=3 (2.7%)). Primary outcomes focused on physical function (SLE n=1 (0.9%), SSc n=15 (13.3%)), mouth opening in SSc (n=4 (5.9%)) and physical capacity (SLE n=2 (1.8%), SSc n=1 (0.9%)). No interventions for mixed connective tissue disease were found. CONCLUSION: There was a great variety in the intervention's content due to differences in body structure, activity limitations and participation restrictions in SLE and SSc. These results highlight the need for personalised, multicomponent, non-pharmacological interventions, which could be delivered as e-health interventions.

Patterns and predictors of skin score change in early diffuse systemic sclerosis from the European Scleroderma Observational Study.

OBJECTIVES: Our aim was to use the opportunity provided by the European Scleroderma Observational Study to (1) identify and describe those patients with early diffuse cutaneous systemic sclerosis (dcSSc) with progressive skin thickness, and (2) derive prediction models for progression over 12 months, to inform future randomised controlled trials (RCTs). METHODS: The modified Rodnan skin score (mRSS) was recorded every 3 months in 326 patients. 'Progressors' were defined as those experiencing a 5-unit and 25% increase in mRSS score over 12 months (±3 months). Logistic models were fitted to predict progression and, using receiver operating characteristic (ROC) curves, were compared on the basis of the area under curve (AUC), accuracy and positive predictive value (PPV). RESULTS: 66 patients (22.5%) progressed, 227 (77.5%) did not (33 could not have their status assessed due to insufficient data). Progressors had shorter disease duration (median 8.1 vs 12.6 months, P=0.001) and lower mRSS (median 19 vs 21 units, P=0.030) than non-progressors. Skin score was highest, and peaked earliest, in the anti-RNA polymerase III (Pol3+) subgroup (n=50). A first predictive model (including mRSS, duration of skin thickening and their interaction) had an accuracy of 60.9%, AUC of 0.666 and PPV of 33.8%. By adding a variable for Pol3 positivity, the model reached an accuracy of 71%, AUC of 0.711 and PPV of 41%. CONCLUSIONS: Two prediction models for progressive skin thickening were derived, for use both in clinical practice and for cohort enrichment in RCTs. These models will inform recruitment into the many clinical trials of dcSSc projected for the coming years. TRIAL REGISTRATION NUMBER: NCT02339441.

Disability, fatigue, pain and their associates in early diffuse cutaneous systemic sclerosis: the European Scleroderma Observational Study.

Objectives: Our aim was to describe the burden of early dcSSc in terms of disability, fatigue and pain in the European Scleroderma Observational Study cohort, and to explore associated clinical features. Methods: Patients completed questionnaires at study entry, 12 and 24 months, including the HAQ disability index (HAQ-DI), the Cochin Hand Function Scale (CHFS), the Functional Assessment of Chronic Illness Therapy-fatigue and the Short Form 36 (SF36). Associates examined included the modified Rodnan skin score (mRSS), current digital ulcers and internal organ involvement. Correlations between 12-month changes were also examined. Results: The 326 patients recruited (median disease duration 11.9 months) displayed high levels of disability [mean (s.d.) HAQ-DI 1.1 (0.83)], with 'grip' and 'activity' being most affected. Of the 18 activities assessed in the CHFS, those involving fine finger movements were most affected. High HAQ-DI and CHFS scores were both associated with high mRSS (ρ = 0.34, P < 0.0001 and ρ = 0.35, P < 0.0001, respectively). HAQ-DI was higher in patients with digital ulcers (P = 0.004), pulmonary fibrosis (P = 0.005), cardiac (P = 0.005) and muscle involvement (P = 0.002). As anticipated, HAQ-DI, CHFS, the Functional Assessment of Chronic Illness Therapy and SF36 scores were all highly correlated, in particular the HAQ-DI with the CHFS (ρ = 0.84, P < 0.0001). Worsening HAQ-DI over 12 months was strongly associated with increasing mRSS (ρ = 0.40, P < 0.0001), decreasing hand function (ρ = 0.57, P < 0.0001) and increasing fatigue (ρ = -0.53, P < 0.0001). Conclusion: The European Scleroderma Observational Study highlights the burden of disability in early dcSSc, with high levels of disability and fatigue, associating with the degree of skin thickening (mRSS). Impaired hand function is a major contributor to overall disability.

Treatment outcome in early diffuse cutaneous systemic sclerosis: the European Scleroderma Observational Study (ESOS).

OBJECTIVES: The rarity of early diffuse cutaneous systemic sclerosis (dcSSc) makes randomised controlled trials very difficult. We aimed to use an observational approach to compare effectiveness of currently used treatment approaches. METHODS: This was a prospective, observational cohort study of early dcSSc (within three years of onset of skin thickening). Clinicians selected one of four protocols for each patient: methotrexate, mycophenolate mofetil (MMF), cyclophosphamide or 'no immunosuppressant'. Patients were assessed three-monthly for up to 24 months. The primary outcome was the change in modified Rodnan skin score (mRSS). Confounding by indication at baseline was accounted for using inverse probability of treatment (IPT) weights. As a secondary outcome, an IPT-weighted Cox model was used to test for differences in survival. RESULTS: Of 326 patients recruited from 50 centres, 65 were prescribed methotrexate, 118 MMF, 87 cyclophosphamide and 56 no immunosuppressant. 276 (84.7%) patients completed 12 and 234 (71.7%) 24 months follow-up (or reached last visit date). There were statistically significant reductions in mRSS at 12 months in all groups: -4.0 (-5.2 to -2.7) units for methotrexate, -4.1 (-5.3 to -2.9) for MMF, -3.3 (-4.9 to -1.7) for cyclophosphamide and -2.2 (-4.0 to -0.3) for no immunosuppressant (p value for between-group differences=0.346). There were no statistically significant differences in survival between protocols before (p=0.389) or after weighting (p=0.440), but survival was poorest in the no immunosuppressant group (84.0%) at 24 months. CONCLUSIONS: These findings may support using immunosuppressants for early dcSSc but suggest that overall benefit is modest over 12 months and that better treatments are needed. TRIAL REGISTRATION NUMBER: NCT02339441.

International Classification of Functioning, Disability and Health Core Set construction in systemic sclerosis and other rheumatic diseases: a EUSTAR initiative.

OBJECTIVES: To outline rationale and potential strategies for rheumatology experts to be able to develop disease-specific Core Sets under the framework of the International Classification of Functioning, Disability and Health (ICF). ICF is a universal framework introduced by the World Health Organization (WHO) to describe and quantify the impact and burden on functioning of health conditions associated with impairment/disability. METHODS: A combined effort of the EULAR Scleroderma Clinical Trial and Research and the ICF Research Branch was initiated to develop an ICF language for scleroderma. From our Medline literature review, using the abbreviation and spelled out version of ICF, we assembled approaches and methodological reasoning for steps of core set development. RESULTS: The ICF can be used for patient care and policy-making, as well as the provision of resources, services and funding. The ICF is used on institutional, regional, national and global levels. Several diseases now have ICF Core Sets. Patients with complex rheumatologic diseases will benefit from a disease-specific ICF Core Set and should be included in all stages of development. ICF Core Set development for rheumatic diseases can be conducted from a number of feasible strategies. CONCLUSION: This overview should help to clarify useful processes leading to development of an ICF Core Set, and also provide a platform for expert groups considering such an endeavour.

EUSTAR biobanking: recommendations for the collection, storage and distribution of biospecimens in scleroderma research.

The European League Against Rheumatism Scleroderma Trials and Research Group (EUSTAR) has established an online database with clinical data of currently more than 8200 patients with systemic sclerosis (SSc). In addition to clinical research, EUSTAR fosters biomolecular studies to develop novel biomarkers and therapies for SSc. High-quality biospecimens are the basis for successful biomolecular studies. The EUSTAR biobanking group has therefore developed recommendations to standardise the collection, storage and distribution of SSc biospecimens at EUSTAR centres. These recommendations consider the scientific challenges associated with biomolecular research in SSc and the organisational requirements of EUSTAR. They were approved by the EUSTAR executive committee as well as the EUSTAR board. Once they become effective, these recommendations will be the basis for international EUSTAR studies with large numbers of SSc biospecimens. These recommendations might also be followed by other SSc consortia to enable exchange of biosamples between different SSc initiatives and might serve as a template for biobanking initiatives in other rheumatic diseases.