Complex relationships between inflammatory manifestations/type 1 and type 2 symptoms in systemic lupus erythematosus: A narrative literature review.

Recent studies have highlighted that systemic lupus erythematosus (SLE) is characterized by different types of symptoms: type 1 symptoms related to inflammation and disease activity and type 2 symptoms such as fatigue, anxiety-depression, and pain. Our aim was to investigate the relation between type 1 and type 2 symptoms, and their impact on health-related quality of life (HRQoL) in SLE. A literature review was conducted about disease activity/type1 and type 2 symptoms. Articles in English published after 2000 were located on Medline via Pubmed. The articles chosen evaluated at least one type 2 symptom or HRQoL using a validated scale in adult patients. Overall, 182 articles were analyzed and 115 were retained including 21 randomized, controlled trials and corresponding to 36 831 patients. We found that in SLE, inflammatory activity/type 1 symptoms were mostly uncorrelated with type 2 symptoms and/or HRQoL. Several studies even showing an inverse relationship. No or weak correlation was observed in 85, 3% (92, 6%), 76, 7% (74, 4%) and 37, 5% (73, 1%) of studies (patients) for fatigue, anxiety-depression, and pain, respectively. For HRQoL, no or weak correlation was observed in 77, 5% of studies (88% of patients). Type 2 symptoms are poorly correlated with inflammatory activity/type 1 symptoms in SLE. Possible explanations and implications for clinical care and therapeutic evaluation are discussed.