Figure 4.

OPN Is a Prognostic Biomarker in SSc

(A) Serum OPN protein levels in an observational cohort of individuals with SSc ILD (N = 102, Michigan cohort) and healthy donors (N = 9).

(B) OPN levels in the Michigan cohort, clinically stratified by disease severity and progression status. Clinical demographic information and categorization definitions are provided in Table S5. Values are mean ± SEM and were analyzed by Mann-Whitney test.

(C) Prognostic effect of serum OPN levels for future FVC change in three SSc cohorts. Shown is a linear regression model of percent predicted FVC (ppFVC) slope adjusted for cohorts, age, sex, and baseline ppFVC with available measurements during 1 (faSScinate, focuSSced) to 2 years (Michigan) of follow-up. Refer to Table S6 for individual cohort analyses.

(D) Prognostic effect of baseline serum OPN levels for skin thickening (MRSS) change in the three SSc cohorts over time. Shown is a linear regression model of ppMRSS slope adjusted for cohorts, age, sex, and baseline MRSS with available measurements. Refer to Table S6 for individual cohort analyses.

(E) Categorical CRISS response proportions of subjects from the focuSSced cohort (placebo arm), stratified by baseline serum OPN, split at median. Fisher’s exact test, 2-tailed, p = 0.0081.

(F) Pharmacodynamic effect on OPN in SSc patients treated with TCZ or placebo (PBO) in the focuSSced cohort. A dotted line represents median OPN levels in age- and sex-matched HC subjects. Values are mean ± SEM. The p value was calculated based on a linear regression model, with the OPN level as response variable and time, treatment, and interaction of time and treatment as covariates.