Evaluation of Type 2 SLE symptoms in patients with a range of lupus nephritis activity

Background Type 2 systemic lupus erythematosus (SLE) symptoms, including fatigue, fibromyalgia, and brain fog, contribute to poor health-related quality of life (HRQoL) in patients with lupus. To test the hypothesis that Type 1 (classical inflammatory lupus) activity is associated with Type 2 SLE activity, we characterized the features of Type 2 SLE in patients with a range of lupus nephritis (LN) activity. Methods This was a cross-sectional study of SLE patients [American College of Rheumatology (ACR) 1997 or Systemic Lupus International Collaborating Clinics (SLICC) 2012 classification criteria] from June 2018 to March 2020. Patients completed the Systemic Lupus Activity Questionnaire (SLAQ) and the Polysymptomatic Distress Scale. Patients were divided into groups based on their renal status. Active nephritis was defined using the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) lupus nephritis parameter. Differences across groups were analyzed by Fisher’s exact test and ANOVA. Results In this cohort of 244 patients (93% female, mean age 43 years, 58% Black), 10% had active nephritis, 35% had historical nephritis, and 55% never had nephritis (non-nephritis). Active nephritis and non-nephritis patients had a similar burden of Type 2 SLE symptoms, despite a difference in Type 1 SLE activity. Patients with active nephritis had higher Type 2 PGA (Physician Global Assessment) scores and reported more Type 2 SLE symptoms than inactive nephritis patients. Patients with inactive nephritis had the lowest Type 2 SLE activity. Conclusions While Type 2 SLE symptoms are common in SLE, our findings suggest that patients with active nephritis experience significant Type 2 SLE symptoms that may be ameliorated as nephritis improves. We also observed that non-nephritis patients had a similar burden of Type 2 SLE symptoms as patients with active nephritis, despite having on average lower Type 1 SLE activity. Therefore, the etiology of Type 2 SLE symptoms is likely multifactorial and may be driven by inflammatory and non-inflammatory biopsychosocial factors. Key Points • Patients with active nephritis experienced significant Type 2 symptoms that may be ameliorated as nephritis improves. • Non-nephritis patients had a similar burden of Type 2 SLE symptoms as patients with active nephritis, despite having on average lower Type 1 SLE activity. • Because etiology of Type 2 SLE symptoms is likely multifactorial and may be driven by inflammatory and non-inflammatory biopsychosocial factors.