Associations between the Composite Response Index in Diffuse Cutaneous Systemic Sclerosis (CRISS), survival and other disease measures

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.

Prediction of damage trajectories in systemic sclerosis using group-based trajectory modelling

OBJECTIVES

Damage accrual in SSc can be tracked using the Scleroderma Clinical Trials Consortium Damage Index (DI). Our goal was to develop a prediction model for damage accrual in SSc patients with early disease.

METHODS

Using patients with <2 years disease duration from Canada and Australia as a derivation cohort, and from the Netherlands as a validation cohort, we used group-based trajectory modelling (GBTM) to determine 'good' and 'bad' latent damage trajectories. We developed a prediction model from this analysis and applied it to patients from derivation and validation cohorts. We plotted the actual DI trajectories of the patients predicted to be in 'good' or 'bad' groups.

RESULTS

We found that the actual trajectories of damage accumulation for lcSSc and dcSSc were very different, so we studied each subset separately. GBTM found two distinct trajectories in lcSSc and three in dcSSc. We collapsed the two worse trajectories in the dcSSc into one group and developed a prediction model for inclusion in either 'good' or 'bad' trajectories. The performance of models using only baseline DI and sex was excellent with ROC AUC of 0.9313 for lcSSc and 0.9027 for dcSSc. Using this model, we determined whether patients would fall into 'good' or 'bad' trajectory groups and then plotted their actual trajectories which showed clear differences between the predicted 'good' and 'bad' cases in both derivation and validation cohorts.

CONCLUSIONS

A simple model using only cutaneous subset, baseline DI and sex can predict damage accumulation in early SSc.

Anemia Is an Indicator for Worse Organ Damage Trajectories in Patients with Systemic Sclerosis: A Retrospective Study

It is important for clinicians to determine the risk of worsening trajectories in SSc patients. The Scleroderma Clinical Trials Consortium (SCTC) Damage Index (DI) has been developed to quantify organ damage and shows good capability for mortality and morbidity prediction in patients with SSc. This retrospective study aimed to describe the SCTC-DI in Chinese SSc patients and to find features predicting worse organ damage trajectories based on SCTC-DI. A total of 433 SSc patients who met the inclusion criteria in the Peking University Third Hospital (PKUTH-SSc) and People’s Hospital SSc cohort (PKUPH-SSc) were recruited for our study. Organ damage was relatively mild in our Chinese SSc cohort compared to other cohorts, with a mean SCTC-DI of 5.21 ± 4.60. We used both SCTC-DI ≥ 6 and ≥4 to define the high burden of organ damage and established two risk models by the LASSO algorithm, which revealed good identification of high organ damage burden (AUC = 0.689, 95% CI 0.636 to 0.742, p < 0.001 in SCTC-DI ≥ 6 model; AUC = 0.694, 95% CI 0.641 to 0.746, p < 0.001 in modified SCTC-DI ≥ 4 model). The anemia index at the baseline was included in these two models and was also independently related to organ damage progression (HR = 1.75, 95% CI 1.16 to 2.66, p = 0.008). In addition, the presence of an anti-Scl-70 autoantibody was also a predictor of progression (HR = 1.91, 95% CI 1.22 to 2.99, p = 0.005). In conclusion, anemia at the baseline was an important indicator for worse organ damage trajectories in SSc patients. We recommend using hemoglobin as a potential biomarker to evaluate organ damage in SSc patients.