The challenges and controversies of measuring disease activity in systemic sclerosis

Prediction of Disease Progression and Clinical Response in Systemic Sclerosis: Experience From a Proof-of-Concept Trial

OBJECTIVE

Using the modified Rodnan skin score (mRSS) as a surrogate for disease activity, a phase 2a study in patients with systemic sclerosis (SSc) measured efficacy of the autotaxin inhibitor ziritaxestat. Mathematical modeling of mRSS was used to predict disease progression, examine candidate trial designs, and predict the probability of successfully discriminating treatment effect.

METHODS

Patients with SSc receiving 600 mg of ziritaxestat or placebo for 24 weeks were included, in addition to data up to week 52 of the open-label extension (OLE). Longitudinal mRSS data were described using a disease progression model; drug effect was a binary variable. Parameters used to predict the OLE mRSS outcome were estimated using data from the 24-week double-blind phase and validated with observed data. Three trial designs were simulated to identify which had the highest probability of detecting a treatment effect. Power to detect a treatment effect was quantified using the simulations.

RESULTS

Maximum decreases from baseline in mRSS were 50.4% (ziritaxestat) and 34.7% (placebo). Study designs based on 300 patients randomized 2:1 or 1:1 to 600 mg of ziritaxestat or placebo had similar probabilities of detecting a significant treatment effect. Power to detect a treatment effect was >80% for all simulations.

CONCLUSION

Disease progression and drug effect could be predicted beyond the range of observed data. This modeling and simulation approach may inform future trial design, including study duration, and predict the probability of success.

Development and Initial Validation of the Novel Scleroderma Clinical Trials Consortium Activity Index

OBJECTIVE

Accurate measurement of disease activity in systemic sclerosis (SSc) remains a significant clinical challenge. The Scleroderma Clinical Trials Consortium (SCTC) convened an Activity Index (AI) Working Group (WG) to develop a novel measure of disease activity (SCTC-AI).

METHODS

Using consensus methodology, we developed a conceptual definition of disease activity. Literature review and expert consensus generated provisional SCTC-AI items, which were reduced by Delphi survey. Provisional items were weighted against a combined endpoint of morbidity and mortality, using time-dependent Cox proportional hazards regression analysis of the Australian Scleroderma Cohort Study (ASCS) (n = 1,254). External validation of the SCTC-AI was performed using data collected from 1,103 Canadian Scleroderma Research Group Study participants.

RESULTS

Disease activity in SSc was defined using consensus methodology as "aspects of disease that are reversible, or can be arrested, with time and, or effective therapy." One-hundred and forty-one provisional SCTC-AI items were generated and reduced using three rounds of Delphi survey and statistical reduction and weighting, against mortality and quality of life measures, yielding a final 24-item index with a maximum possible score of 140. Survival analysis in an external cohort showed a graded relationship between disease activity scores and survival (P < 0.01).

CONCLUSION

We present a novel instrument to quantify the burden of disease activity in SSc. We have employed a rigorous consensus-based process in combination with data-driven methods to develop an instrument that has face, content, and criterion validity. Further work is required to fully validate and confirm the construct and discriminative validity of the SCTC-AI.

The association between the neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio, and monocyte-to-lymphocyte ratio and systemic sclerosis and its complications: a systematic review and meta-analysis

Introduction

The identification of new, easily measurable biomarkers might assist clinicians in diagnosing and managing systemic sclerosis (SSc). Although the full blood count is routinely assessed in the evaluation of SSc, the diagnostic utility of specific cell-derived inflammatory indices, i.e., neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and monocyte-to-lymphocyte ratio (MLR), has not been critically appraised in this patient group.

Methods

We conducted a systematic review and meta-analysis of studies investigating the NLR, PLR, and MLR, in SSc patients and healthy controls and in SSc patients with and without relevant complications. PubMed, Scopus, and Web of Science were searched from inception to 23 February 2024. Risk of bias and certainty of evidence were assessed using validated tools.

Results

In 10 eligible studies, compared to controls, patients with SSc had significantly higher NLR (standard mean difference, SMD=0.68, 95% CI 0.46 to 0.91, p<0.001; I2 = 74.5%, p<0.001), and PLR values (SMD=0.52, 95% CI 0.21 to 0.83, p=0.001; I2 = 77.0%, p=0.005), and a trend towards higher MLR values (SMD=0.60, 95% CI -0.04 to 1.23, p=0.066; I2 = 94.1%, p<0.001). When compared to SSc patients without complications, the NLR was significantly higher in SSc with interstitial lung disease (ILD, SMD=0.31, 95% CI 0.15 to 0.46, p<0.001; I2 = 43.9%, p=0.11), pulmonary arterial hypertension (PAH, SMD=1.59, 95% CI 0.04 to 3.1, p=0.045; I2 = 87.6%, p<0.001), and digital ulcers (DU, SMD=0.43, 95% CI 0.13 to 0.74, p=0.006; I2 = 0.0%, p=0.49). The PLR was significantly higher in SSc patients with ILD (SMD=0.42, 95% CI 0.25 to 0.59, p<0.001; I2 = 24.8%, p=0.26). The MLR was significantly higher in SSc patients with PAH (SMD=0.63, 95% CI 0.17 to 1.08, p=0.007; I2 = 66.0%, p=0.086), and there was a trend towards a higher MLR in SSc patients with ILD (SMD=0.60, 95% CI -0.04 to 1.23, p=0.066; I2 = 94.1%, p<0.001).

Discussion

Pending the results of appropriately designed prospective studies, the results of this systematic review and meta-analysis suggest that blood cell-derived indices of inflammation, particularly the NLR and PLR, may be useful in the diagnosis of SSc and specific complications.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42024520040.

Composite measures to assess disease damage, disease severity and treatment response in systemic sclerosis clinical trials

PURPOSE OF REVIEW

The aim of this study was to summarize the composite outcome measures available to assess disease damage, severity and treatment response in systemic sclerosis (SSc).

RECENT FINDINGS

There have been many recent efforts to rigorously develop and validate composite outcome measures to assess the totality of the impact of SSc on patients. All initiatives have used both consensus and data-driven methods. Recently developed are a SSc-specific damage index, a patient-reported disease impact questionnaire (ScleroID) and a treatment response index (ACR-CRISS).

SUMMARY

Multiorgan, composite measures are being increasingly applied to assess treatment efficacy in clinical trials. Although a fully validated, disease-specific composite measure is not yet available, there has been significant recent progress towards developing measures of treatment response, damage and overall impact of SSc for application in randomized controlled trials.

[Characteristics of patients with systemic sclerosis who develop interstitial lung disease]

Background

Systemic sclerosis associated-interstitial lung disease (SSc-ILD) show a high mortality. The factors associated SSc-ILD have shown variability in different populations. There are few studies in Mexican mestizos.

Objective

To analyze the epidemiological, clinical and paraclinical factors associated with SSc-ILD.

Material and methods

Cross-sectional study, where patients > 18 years of age with a diagnosis of SSc according to EULAR/ACR 2013 criteria and diagnosis of ILD by forced vital capacity (FVC) < 70% and > 5% of affected lung area on tomography were included. The strength of association of the factors for ILD was measured by odds ratio (OR) with 95% confidence intervals (95% CI). The significant variables were analyzed by multiple logistic regression with adjustment.

Results

Of the 80 patients with SSc, 38 (47.5%) had ILD. Risk factors such as smoking, higher activity index, lower FVC, anti-topoisomerase I antibodies, and protective factors such as a limited SSc, early capillaroscopic pattern, and anti-centromere antibodies (ACA) were associated with ILD. In the multivariate analysis, a higher activity index with OR 4.17, (95% CI 2.01-8.65) persisted as a risk factor, while ACA with OR 0.17, (95% CI 0.03-0.85) persisted as a protective factor associated with SSc-ILD.

Conclusions

A higher index of activity and ACA persisted as factors associated with SSc-ILD.

Application and performance of disease activity indices proposed for patients with systemic sclerosis in an international cohort of patients with juvenile systemic sclerosis

Objectives

Juvenile systemic sclerosis is a rare childhood disease. Three disease activity indices have been published for adult patients with systemic sclerosis: the European Scleroderma Study Group Index, a modified version of the European Scleroderma Study Group Index and the revised European Scleroderma Trials and Research index. The objective of this study was to determine the feasibility and performance of the three disease activity indices in a prospectively followed cohort of patients with juvenile systemic sclerosis.

Methods

The analysis cohort was selected from the prospective international inception cohort enrolling juvenile systemic sclerosis patients. The correlation of the disease activity indices with the physicians' and the patients' global assessment of disease activity was determined. The disease activity indices were compared between patients with active and inactive disease. Sensitivity to change between 6- and 12-month follow-up was investigated by mixed models.

Results

Eighty percent of the 70 patients had a diffuse cutaneous subtype. The revised European Scleroderma Trials and Research index was highly correlated with the physician-reported global disease activity/parents-reported global disease activity (r = 0.74/0.64), followed by the European Scleroderma Study Group activity index (r = 0.61/0.55) and the modified version of the European Scleroderma Study Group activity index (r = 0.51/0.43). The disease activity indices significantly differed between active and inactive patients. The disease activity indices showed sensitivity to change between 6- and 12-month follow-up among patients who improved or worsened according to the physician-reported global disease activity and the parents-reported global disease activity.

Conclusion

Overall, no disease activity score is superior to the other, and all three scores have limitations in the application in juvenile systemic sclerosis patients. Furthermore, research on the concept of disease activity and suitable scores to measure disease activity in patients with juvenile systemic sclerosis is necessary in future.

Do we have good activity indices in systemic sclerosis?

BACKGROUND

No fully validated index is available for assessing overall disease activity in systemic sclerosis (SSc).

OBJECTIVES

To estimate the effect of disease activity as measured by different disease activity indices on the risk of subsequent organ damage.

METHODS

The European Systemic sclerosis study group activity index (EScSG AI), the European Scleroderma Trials and Research Group Activity Index (r-EUSTAR AI), 12 point activity index proposed by Minier (12point AI) were calculated for 91 patients; the CRISS (The Composite Response Index for Systemic Sclerosis) for patients included after 2016. Data were analysed by parametric and non-parametric tests and logistic regression.

RESULTS

EscSG AI, r-EUSTAR AI and 12point AI correlated with lung involvement. EScSG AI and r-EUSTAR AI correlated with diffuse skin involvement. EscSG AI correlated with digital ulcers and diffuse cutaneous involvement and r-EUSTAR AI with renal crisis. Bivariate analysis showed an inverse correlation between the three disease activity scores and forced vital capacity (FVC) (p<0.001) and diffusing capacity for carbon monoxide (DLCO) (p<0.001) and positive correlation with pulmonary fibrosis (p<0.001), modified Rodnan skin score (mRSS) (p<0.001), health assessment questionnaire (HAQ) (p<0.001), systolic pulmonary pressure (sPAP) (p<0.001), C-reactive protein (CRP) (p<0.001) and capillaroscopy scoring (p<0.001) at both baseline visit and at the 3-year follow-up visit. Logistic regression revealed that baseline EScSG AI adjusted for gender and age and that baseline 12-point AI both adjusted and unadjusted predicted worse skin involvement at 3-year follow-up; while adjusted EScSG AI predicted decreasing of DLCO. Also, 12-point AI predicted decline of FVC and higher HAQ scores at 3-year follow up; while baseline r-EUSTAR AI was able to predict muscular deterioration, decline of FVC and the increase of HAQ score during 3 years of following. An active disease according to EScSG AI at first visit predicted progression of joint involvement while an active disease at baseline showed by r-EUSTAR AI predicted muscular deterioration, FVC and DLCO worsening, as well as an increasing in HAQ score during the follow-up period. r-EUSTAR AI was the only score to predict the decrease of FVC in a multiple regression prediction model [OR= 1.306 (1.025, 1.665), p=0.31] while baseline EScSG AI best predicted worsening of DLCO [OR=1.749 (1.104, 2.772), p=0.017].

CONCLUSION

Our study could not establish a gold standard to assess disease activity in SSc; especially EscSG AI and r-EUSTAR AI could quantify and predict major organ involvement in daily practice. CRISS can be useful as an outcome measure for patients with short disease duration included in clinical studies.

Increased Frequency of Activated Switched Memory B Cells and Its Association With the Presence of Pulmonary Fibrosis in Diffuse Cutaneous Systemic Sclerosis Patients

Disease-associated, high-affinity pathological autoantibody production is a well-described consequence of immune dysregulation affecting B cells in systemic sclerosis (SSc), including the distribution of B-cell subsets. We have previously shown that the increased relative frequency of CD19+CD27+IgD- switched memory B cells is associated with the severe form of SSc. This study sought to analyze memory B cell subsets using an extended range of markers for further subdivision based on CD19, IgD, CD27, CD38 and CD95 phenotype, to define relationship between the alterations of memory B cell subsets and the clinical features of SSc. Peripheral blood samples were obtained from 21 SSc patients, including 14 diffuse (dcSSc) and 7 limited (lcSSc) cutaneous SSc patients, with disease duration of 2.7 ( ± 1.6) years. After purification of CD19+ B cells, multiparametric flow cytometry was performed and the frequencies of CD19+IgD-CD27-CD38+ double negative (DN) 1, CD19+IgDloCD27+CD38+ unswitched, CD19+IgD-CD27+CD38+CD95- resting switched and CD19+IgD-CD27+CD38-CD95+ activated switched memory (ASM) B cells were determined, and correlated with clinical features of SSc. The dcSSc patients had a higher frequency of ASM B cells (p = 0.028) compared to lcSSc patients. The percentage of ASM B cells was elevated in anti-Scl-70 (anti-topoisomerase I) antibody positive patients compared to negative patients (p = 0.016). Additionally, the frequency of ASM B cells was also increased in patients with pulmonary fibrosis (p = 0.003) suggesting that patients with severe form of SSc have higher ASM B cell ratios. Furthermore, the ratio of DN1 B cells was decreased (p = 0.029), while the level of anti-citrate synthase IgG natural autoantibody was elevated (p = 0.028) in patients with active disease. Our observations on the increase of ASM B cells in dcSSc and in patients with pulmonary fibrosis may point to the association of this alteration with the severe form of the disease. Functionally the correlation of ASM B cells as effector memory-plasma cell precursors with anti-topoisomerase I antibody positivity could reflect their contribution to pathological autoantibody production, whereas the decrease of memory precursor DN B cells and the increase of anti-citrate synthase IgG autoantibody may have potential significance in the assessment of disease activity.

Considerations for a combined index for limited cutaneous systemic sclerosis to support drug development and improve outcomes

Systemic sclerosis (SSc; systemic scleroderma) is characterized by a heterogeneous range of clinical manifestations. SSc is classified into limited cutaneous SSc (lcSSc) and diffuse cutaneous subgroups (dcSSc) based on the extent of skin involvement. Randomized controlled trials in scleroderma have mainly focused on dcSSc partly because the measurement of skin involvement, critical for evaluating a therapeutic intervention is more dynamic in this subset. Nonetheless, lcSSc, the most common cutaneous subset (about 2/3), is also associated with significant morbidity and detrimental impact on health-related quality of life. The lack of interventional studies in lcSSc is partly due to a lack of relevant outcome measures to evaluate this subgroup. Combining several clinically meaningful outcomes selected specifically for lcSSc may improve representativeness in clinical trials and responsiveness of outcomes measured in randomized controlled trials. A composite index dedicated to lcSSc combining such relevant outcomes could advance clinical trial development for lcSSc by providing the opportunity to test and select among candidate drugs that could act as disease-modifying treatments for this neglected subgroup of SSc. This proposed index would include items selected by expert physicians and patients with lcSSc across domains grounded in the lived experience of lcSSc. This article reviews the reasons behind the relative neglect of lcSSc, discusses the current state of outcome measures for lcSSc, identifies challenges, and proposes a roadmap for a combined lcSSc-specific treatment response index.

Can Patient-Reported Symptoms Be Used to Measure Disease Activity in Systemic Sclerosis?

OBJECTIVE

To evaluate the association between patient-reported symptoms and changes in disease activity over time in systemic sclerosis (SSc).

METHODS

Using data from 1,636 patients enrolled in the Australian Scleroderma Cohort Study, we used generalized estimating equations to determine the relationship between patient-reported worsening of Raynaud's phenomenon (RP), skin involvement, and breathlessness in the month preceding each study visit and features of disease activity in the corresponding organ systems. The associations between the following parameters were analyzed: patient-reported worsening RP and the presence of new-onset digital pitting and digital ulcers; patient-reported worsening skin involvement and increasing modified Rodnan skin thickness score (MRSS); new areas of skin involvement and new-onset joint contractures; patient-reported worsening breathlessness and deteriorating respiratory functions test (RFT) results, indicated by a 10% decrease in forced vital capacity (FVC) and a 15% decrease in diffusing capacity for carbon monoxide (DLco), new-onset interstitial lung disease (ILD), and new-onset pulmonary arterial hypertension (PAH).

RESULTS

We found a significant association between patient-reported worsening RP and the presence of digital ulcers (odds ratio [OR] 1.53 [95% confidence interval (95% CI) 0.60-0.93]), patient-reported worsening skin involvement and increasing MRSS (OR 2.10 [95% CI 1.54-2.86]), and worsening patient breathlessness and deteriorating RFTs (FVC OR 2.12 [95% CI 1.70-2.65]; DLco OR 1.97 [95% CI 1.34-2.02]), new-onset ILD (OR 1.91 [95% CI 1.40-2.61]), and new-onset PAH (OR 5.08 [95% CI 3.59-7.19]).

CONCLUSION

These results demonstrate that patient-reported symptoms are associated with clinically meaningful changes in disease activity in patients with SSc. This suggests that when objective measures of change in disease status are unavailable, patient-reported symptoms could be used to indicate a change in SSc disease activity.

Performance of the 2017 EUSTAR activity index in an scleroderma cohort

Assessment of disease activity in systemic sclerosis (SSc) is limited by the absence of a fully validated, multisystem measure of disease activity. The European Scleroderma Trials and Research Group (EUSTAR) SSc activity index (EScSG-AI) was recently revised, and a validation study within the EUSTAR cohort was performed. In this study, we evaluated the performance of the revised EScSG-AI in an external Australian cohort. The association between the EScSG-AI and the physician global assessment of disease activity (PhGA), both collected prospectively at each annual visit over up to 12 years follow-up, was evaluated using Pearson's correlation coefficient and Cohen's kappa coefficient. Generalized linear modelling and time-dependent Cox regression analysis were performed to determine the association of disease activity measured by the EScSG-AI and the summed Medsger Severity Scale (MSS) and death, respectively. There was a moderate correlation between EScSG-AI and PhGA scores (r 0.42, p < 0.001) and moderate association between rising EScSG-AI and summed MSS (r 0.60, p < 0.001). High disease activity, measured by the EScSG-AI at any time during follow-up, was associated with a hazard ratio of 2.07 (95% CI 1.51-2.79) for mortality. The EScSG-AI has a moderate correlation with physician-assessed SSc disease activity. This suggests that the criterion and construct validity of the EScSG-AI are yet to be demonstrated in an external cohort of SSc patients. Key Points •There remains no gold standard measure of SSc disease activity. •The revised 2017 EUSTAR SSc disease activity index shows moderate correlation with physician-rated global disease activity. •Significant work remains to develop a validated multisystem measure of disease activity in SSc.

Volumetric Cone Beam Computed Tomography for the Assessment of Oral Manifestations in Systemic Sclerosis: Data from an EUSTAR Cohort

Background: Oral health issues are commonly reported in systemic sclerosis (SSc), comprising a broad spectrum of manifestations, e.g., reduced mouth opening, periodontal disease, increased periodontal ligament (PDL) space width, and mandibular resorption. We aimed to assess oral radiographic abnormalities, particularly PDL space widening and erosions, and to identify potential relations with disease measures. Methods: cross-sectional study in 43 SSc and matching controls receiving systematic oral assessments (full mouth dental/periodontal) and imaging (radiographs and cone beam computed tomography (CBCT)). Associations between disease variables and radiologic findings were investigated by univariate and multivariate analysis (SPSS-v.20, p < 0.05). Results: CBCT demonstrated generalized PDL space widening in up to half SSc, with at least one tooth involved, essentially in the posterior region (p < 0.05). Significant correlations between number of teeth with PDL space widening and disease severity, skin score, disease subset, topoisomerase I specificity, age, and disease duration were reported (p < 0.05). Additionally, mandibular erosions were described in one out of four patients, commonly condylar erosions. Conclusions: Tridimensional CBCT approach confirmed widening of PDL and mandibular erosions as common dental findings in scleroderma. Furthermore, widened PDL spaces correlated with several disease characteristics including severity, skin extent, and antibody profile.