Symptom-based stratification of patients with primary Sjögren's syndrome: multi-dimensional characterisation of international observational cohorts and reanalyses of randomised clinical trials

Background Heterogeneity is a major obstacle to developing effective treatments for patients with primary Sjögren's syndrome. We aimed to develop a robust method for stratification, exploiting heterogeneity in patient-reported symptoms, and to relate these differences to pathobiology and therapeutic response. Methods We did hierarchical cluster analysis using five common symptoms associated with primary Sjögren's syndrome (pain, fatigue, dryness, anxiety, and depression), followed by multinomial logistic regression to identify subgroups in the UK Primary Sjögren's Syndrome Registry (UKPSSR). We assessed clinical and biological differences between these subgroups, including transcriptional differences in peripheral blood. Patients from two independent validation cohorts in Norway and France were used to confirm patient stratification. Data from two phase 3 clinical trials were similarly stratified to assess the differences between subgroups in treatment response to hydroxychloroquine and rituximab. Findings In the UKPSSR cohort (n=608), we identified four subgroups: Low symptom burden (LSB), high symptom burden (HSB), dryness dominant with fatigue (DDF), and pain dominant with fatigue (PDF). Significant differences in peripheral blood lymphocyte counts, anti-SSA and anti-SSB antibody positivity, as well as serum IgG, κ-free light chain, β2-microglobulin, and CXCL13 concentrations were observed between these subgroups, along with differentially expressed transcriptomic modules in peripheral blood. Similar findings were observed in the independent validation cohorts (n=396). Reanalysis of trial data stratifying patients into these subgroups suggested a treatment effect with hydroxychloroquine in the HSB subgroup and with rituximab in the DDF subgroup compared with placebo. Interpretation Stratification on the basis of patient-reported symptoms of patients with primary Sjögren's syndrome revealed distinct pathobiological endotypes with distinct responses to immunomodulatory treatments. Our data have important implications for clinical management, trial design, and therapeutic development. Similar stratification approaches might be useful for patients with other chronic immune-mediated diseases. Funding UK Medical Research Council, British Sjogren's Syndrome Association, French Ministry of Health, Arthritis Research UK, Foundation for Research in Rheumatology

The LupusQoL and Associations with Demographics and Clinical Measurements in Patients with Systemic Lupus Erythematosus

Objective. Having developed and validated a disease-specific health-related quality of life (HRQOL) measure for patients with systemic lupus erythematosus (SLE), the LupusQoL, we determined its relationship to demographic and clinical measurements in a group of patients with SLE. Methods. A group of 322 outpatients completed the LupusQoL. Demographic (age, sex, marital status, ethnicity) and clinical variables (disease duration, disease activity, damage) were recorded. Associations between the 8 LupusQoL domains and age, disease duration, disease activity, and damage were explored using Spearman’s correlation coefficients. Differences in LupusQoL scores were examined for sex and marital status using the Mann-Whitney U test. Ethnic groups were compared using ANOVA. Results. All domains of LupusQoL were impaired, with fatigue (56.3) being the worst affected and body image (80.0) the least. The correlations between the LupusQoL domain scores and age (r = −0.01 to −0.22) and disease duration (r = 0 to 0.16) were absent or weak. Similarly, there were no significant differences in the LupusQoL scores regarding sex, marital status, or the 3 main ethnic groups (Black-Caribbean, Asian, White). Although there were statistically significant correlations between the scores of the LupusQoL domains and some scores of the British Isles Lupus Assessment Group index (r = −0.22 to 0.09) and the Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index (r = −0.29 to 0.21), these were weak. Conclusion. HRQOL was impaired in this cohort of outpatients with SLE as assessed by the validated lupus-specific LupusQoL. There were no clinically important associations between the 8 domains of the LupusQoL and clinical or demographic variables in this group of patients. Thus, the LupusQoL is a relatively independent outcome measure in patients with SLE