Munroe, Melissa E.

Abstract Processes that lead to clinical illness in SLE years before diagnosis are not well characterized. This study evaluates the temporal relationship between autoantibody production, cytokine levels and the onset of SLE. Serial sera from 60 SLE cases before diagnosis with no ACR criteria to SLE classification (average timespan=4.4 years) and matched healthy controls (HC) were obtained from the DODSR. Sera samples were tested for autoantibodies (BioPlex2200), C-reactive protein (hs-CRP), Von Willebrand’s Factor (VWF) and 32 soluble inflammatory mediators, including cytokines, chemokines, and soluble receptors. Patient samples before ACR classification had significant (p < 0.01) alterations in 16 soluble mediators of inflammation, as well as VWF and hs-CRP. TNF Receptor levels, TNFRI, TNFRII, BLyS, and APRIL, dramatically increased as lupus classification approached (p < 0.001). The increase in TNFR shedding parallels the accumulation of autoantibodies in SLE cases. Interferon (IFN)-associated mediators of inflammation, IFN-γ, IP-10, MIG, and MIP-1α (p < 0.01), were also increased leading up to classification. That these alterations are present prior to the transition to active SLE suggests that multiple perturbations in immune-mediated inflammatory processes occur long before clinical classification and suggest that high-risk, pre-clinical individuals, can be identified before their illness is clinically manifested and damage occurs.

ObjectiveSystemic lupus erythematosus (SLE) is marked by immune dysregulation linked to varied clinical disease activity. Using a unique longitudinal cohort of SLE patients, this study sought to identify optimal immune mediators informing an empirically refined flare risk index (FRI) reflecting altered immunity prior to clinical disease flare.MethodsThirty‐seven SLE‐associated plasma mediators were evaluated by microfluidic immunoassay in 46 samples obtained in SLE patients with an imminent clinical disease flare (preflare) and 53 samples obtained in SLE patients without a flare over a corresponding period (pre‐nonflare). SLE patients were selected from a unique longitudinal cohort of 106 patients with classified SLE (meeting the American College of Rheumatology 1997 revised criteria for SLE or the Systemic Lupus International Collaborating Clinics 2012 revised criteria for SLE). Autoantibody specificities, hybrid SLE Disease Activity Index (hSLEDAI) scores, clinical features, and medication usage were also compared at preflare (mean ± SD 111 ± 47 days prior to flare) versus pre‐nonflare (99 ± 21 days prior to nonflare) time points. Variable importance was determined by random forest analysis with logistic regression subsequently applied to determine the optimal number and type of analytes informing a refined FRI.ResultsPreflare versus pre‐nonflare differences were not associated with demographics, autoantibody specificities, hSLEDAI scores, clinical features, nor medication usage. Forward selection and backward elimination of mediators ranked by variable importance resulted in 17 plasma mediator candidates differentiating preflare from pre‐nonflare visits. A final combination of 11 mediators best informed a newly refined FRI, which achieved a maximum sensitivity of 97% and maximum specificity of 98% after applying decision curve analysis to define low, medium, and high FRI scores.ConclusionWe verified altered immune mediators associated with imminent disease flare, and a subset of these mediators improved the FRI to identify SLE patients at risk of imminent flare. This molecularly informed, proactive management approach could be critical in prospective clinical trials and the clinical management of lupus.

ObjectiveSystemic lupus erythematosus (SLE) and other autoimmune diseases cause significant morbidity. Identifying populations at risk of developing SLE is essential for curtailing irreversible inflammatory damage. The aim of this study was to identify factors associated with transition to classified disease that would inform our understanding of the risk of SLE.MethodsPreviously identified blood relatives of patients with SLE, who had <4 American College of Rheumatology (ACR) classification criteria for SLE at baseline, were enrolled in this follow‐up study (n = 409 unaffected relatives). Participants provided detailed family, demographic, and clinical information, including the SLE‐specific portion of the Connective Tissue Disease Screening Questionnaire (SLE‐CSQ). Serum and plasma samples were tested for the presence of lupus‐associated autoantibodies and 52 soluble mediators. Generalized estimating equations (GEEs) were applied to identify factors predictive of disease transition.ResultsOf the 409 unaffected relatives of SLE patients, 45 (11%) had transitioned to classified SLE at follow‐up (mean time to follow‐up 6.4 years). Relatives who transitioned to SLE displayed more lupus‐associated autoantibody specificities and higher SLE‐CSQ scores (P < 0.0001) at baseline than did relatives who did not transition. Importantly, those who had developed SLE during the follow‐up period also had elevated baseline plasma levels of inflammatory mediators, including B lymphocyte stimulator, stem cell factor (SCF), and interferon‐associated chemokines (P ≤ 0.02), with concurrent decreases in the levels of regulatory mediators, transforming growth factor β (TGFβ), and interleukin‐10 (P ≤ 0.03). GEE analyses revealed that baseline SLE‐CSQ scores or ACR scores (number of ACR criteria satisfied) and plasma levels of SCF and TGFβ, but not autoantibodies, were significant and independent predictors of SLE transition (P ≤ 0.03).ConclusionPreclinical alterations in levels of soluble mediators may predict transition to classified disease in relatives of SLE patients. Thus, immune perturbations precede SLE classification and can help identify high‐risk relatives for rheumatology referral and potential enrollment in prevention trials.