Other tipoffs to early SLE
Two separate teams of British researchers have advanced the field in a highly practical way. One group showed in a study of 1,739 newly diagnosed SLE patients and 6,956 controls that in the 5 years prior to diagnosis, the SLE group averaged 9.2 primary care visits per year, compared with 3.8 for controls. The visits clustered around nonspecific complaints of arthritis and arthralgias, alopecia, and rash (Arthritis Care Res. 2017 Jun;69[6]:833-41).
“An accumulating number of primary care office visits and referrals over time should raise suspicion,” Dr. Mosca said.
Other investigators, working with 1,426 cases of newly diagnosed SLE in the U.K. Clinical Practice Research Database, observed that the proportion of patients with disease manifestations in three or more British Isles Lupus Activity Group (BILAG) symptom domains rose from 18.7% at 3 years prior to diagnosis to 39.7% in the year before diagnosis (Lupus Sci Med. 2017 Feb 10;4[1]:e000172. doi: 10.1136/lupus-2016-000172).
“These patients accrue clinical manifestations. It’s not just one symptom, it’s more of a state of being unwell. This is a suspicious factor for the development of lupus,” she continued.
And just as patients who will eventually be diagnosed with SLE accrue a growing number of signs and symptoms during the run up to diagnosis, they also accrue multiple autoantibodies. Moreover, as demonstrated by a multicenter group of U.S. investigators, patients also develop elevated levels of multiple soluble inflammatory markers more than 3.5 years prior to diagnosis of SLE. These include interleukins-5 and -6 and interferon-gamma. And less than 10 months prior to being classified as having SLE, patients develop significantly higher levels of B lymphocyte stimulator (BLyS) and a proliferation-inducing ligand known as APRIL. The investigators developed a predictive model incorporating IL-5, -6, and interferon-gamma levels with antinuclear antibody status that identified future SLE patients with 84% accuracy more than 3.5 years before diagnosis. This could prove useful in selecting high-risk patients for clinical prevention trials (J Autoimmun. 2016 Nov;74:182-93).
Researchers at the University of Leeds (England) have also zeroed in on interferon activity as playing a key role in progression from asymptomatic antinuclear antigen positivity, which is present in up to 25% of the general population, to symptomatic autoimmune connective tissue disease, which affects less than 1%. A multivariate logistic regression analysis identified two independent predictors of development of autoimmune connective tissue disease within the next 12 months: a family history of autoimmune rheumatic disease, which was associated with an 8.2-fold increased risk; and positivity for a pattern of interferon-stimulated gene activity they call IFN-Score-B (Ann Rheum Dis. 2018 Oct;77[10]:1432-9).
All of this work has led up to what Dr. Mosca called “a glance into the future”: the National Institutes of Health–supported Study of Anti-Malarials in Incomplete Lupus Erythematosus (SMILE), which is now recruiting patients. This randomized, double-blind, placebo-controlled multicenter U.S. trial involves patients who are antinuclear antibody positive at a titer of 1:80 or more plus one or two additional criteria from the SLICC classification scheme. Participants are being randomized to 96 weeks of hydroxychloroquine or placebo. The goal is to learn whether hydroxychloroquine can slow disease progression, with the primary endpoint being the number of SLICC criteria met at the study’s end. The trial will also scrutinize potential biomarkers that could be used to guide treatment decisions (Trials. 2018 Dec 20;19[1]:694. doi: 10.1186/s13063-018-3076-7).
Dr. Mosca reported serving as an adviser to UCB and Lilly.