Objectives To investigate whether abnormal BMI is associated with adverse health-related quality of life (HRQoL) outcome, including severe fatigue, after 52 weeks of standard therapy plus belimumab or placebo in patients with SLE. Methods We analysed data from the BLISS-52 (NCT00424476) and BLISS-76 (NCT00410384) trials (n = 1684). Adverse HRQoL was defined as SF-36 scores ≤ the fifth percentile in age- and sex-matched US population-based subjects, and FACIT-F scores <30. We compared BMI groups using the Pearson’s χ2 test, and assessed independence with multivariable logistic regression analysis. Results Overweight (BMI ≥25 kg/m2) and obese (BMI ≥30 kg/m2) patients showed increased likelihood to exhibit adverse SF-36 physical component summary (OR: 1.8; 95% CI: 1.4, 2.3; P <0.001 and OR: 2.4; 95% CI: 1.8, 3.2; P <0.001, respectively) and FACIT-F (OR: 1.3; 95% CI: 1.1, 1.6; P = 0.010 and OR: 1.5; 95% CI: 1.2, 2.0; P = 0.002, respectively) scores at week 52. Underweight was associated with adverse SF-36 mental component summary scores, also after adjustment for sex, ancestry, age, disease duration, disease activity, organ damage and prednisone dose during the study period (OR: 2.1; 95% CI: 1.2, 3.6; P = 0.007). Addition of belimumab to standard therapy independently protected against adverse SF-36 general health (OR: 0.8; 95% CI: 0.6, 1.0; P = 0.025) and FACIT-F < 30 (OR: 0.8; 95% CI: 0.6, 1.0; P = 0.018). Conclusion Overweight and obesity contributed to adverse physical and mental HRQoL outcomes after therapeutic intervention in SLE patients, and underweight contributed to adverse mental HRQoL outcome. A protective effect of belimumab against adverse general health and severe fatigue was implicated.

C-reactive protein (CRP), a humoral component of the innate immune system with important functions in host-defense, is extensively used as a sensitive biomarker of systemic inflammation. During inflammation, hepatocyte-derived CRP rises dramatically in the blood due to increased interleukin-6 (IL-6) levels. Reliable detection of CRP in saliva, instead of blood, would offer advantages regarding sampling procedure and availability but using saliva as a diagnostic body fluid comes with challenges. The aims of this study were to evaluate associations between salivary CRP, total protein levels in saliva and serum CRP. Furthermore, we examined associations with plasma IL-6, body mass index (BMI), tobacco smoking and age. Salivary CRP was investigated by ELISA in 107 middle-aged participants from the general population. We employed spectrophotometric determination of total protein levels. Correlation analyses were used for associations of salivary CRP with serum CRP (turbidimetry), plasma IL-6 (Luminex®), BMI and smoking habits. Salivary median CRP was 68% higher (p=0.009), and total protein levels were 167% higher (p<0.0001), in morning compared to evening saliva. The correlation coefficients between serum and salivary CRP were low to moderate, but stronger for evening than morning saliva. Plasma IL-6 correlated significantly with serum CRP (rs=0.41, p<0.01), but not with morning or evening salivary CRP. Non-smokers showed 103% higher salivary CRP levels (p=0.015), whereas serum CRP was independent of smoking status. As opposed to CRP in serum, salivary CRP was not associated with BMI. Salivary CRP was 90% higher among the age interval 60–69 years compared to subjects aged 45–59 (p=0.02) while serum CRP levels did not differ between the age groups. In conclusion, CRP in saliva did not straightforwardly reflect serum concentrations. This raises questions regarding adequate reflection of biological events. The pronounced diurnal salivary CRP pattern accentuates the importance of standardizing the time-point of sampling.

Objectives To investigate the discriminative ability of EQ-5D-3L full health state (FHS) in clinical trials of SLE, and identify factors associated with FHS after treatment. Methods Data from the BLISS-52 (NCT00424476) and BLISS-76 (NCT00410384) trials of belimumab (N = 1684) were utilised. FHS was defined as a response of no problems in all five EQ-5D-3L dimensions, yielding an index score of 1. The Pearson’s chi-square or Fisher’s exact test was employed for comparisons, and logistic regression for adjustments and assessment of independence. Results We demonstrated higher EQ-5D-3L FHS frequencies among patients given standard therapy (ST) plus the licensed belimumab dose versus ST alone (26.1% versus 19.4%; P = 0.001; week 52), and within SRI-4 responders versus non-responders (27.0% versus 19.8%; P < 0.001; week 52) from week 36 to 52. In multivariable regression analysis, SLEDAI-2K (OR: 0.90; 95% CI: 0.87 − 0.94; P < 0.001) and SLICC/ACR Damage Index (OR: 0.79; 95% CI: 0.69 − 0.91; P = 0.001) scores were independently associated with lower FHS frequencies at week 52, while adding monthly infusions of belimumab 10 mg/kg to ST favoured FHS perception (OR: 1.60; 95% CI: 1.15 − 2.24; P = 0.006). Add-on belimumab 10 mg/kg yielded higher FHS frequencies in antimalarial users versus non-users (29.9% versus 20.1%; P = 0.011), and in anti-dsDNA and anti-Sm positive versus negative patients (31.4% versus 13.4%; P < 0.001 and 33.0% versus 22.6%; P = 0.010, respectively), whereas no significant differences were observed in patients given ST alone. Conclusion EQ-5D-3L FHS distinguished belimumab from placebo and responders from non-responders, and exhibited known-group validity in subgroup analysis. FHS may prove a useful patient-reported outcome in SLE studies.