Article Text
Abstract
Background The Type 1 & 2 SLE Model categorizes signs and symptoms as Type 1 (arthritis, nephritis, and rash) and Type 2 (fatigue, brain fog, and widespread pain). It is currently unknown whether Type 2 SLE symptoms vary over time. In this study, we measured longitudinal changes in Type 2 SLE activity as measured by the Polysymptomatic Distress (PSD) Scale.
Methods Lupus patients meeting ACR or SLICC criteria in a university lupus registry completed the PSD. SLEDAI scores were also recorded. Patients with ≥2 clinical visits over a 52-week period were included. Groups were selected based on mean, indicating severity of symptoms, and the standard deviation, indicating variability of symptoms, of PSD scores across visits. Differences across groups were assessed with chi-square and ANOVA tests.
Results The study included 204 patients. Four Type 2 SLE activity groups were identified (figure 1): chronic low (n=71; 35%), variable low (n=31, 15%), chronic high (n=31, 15%), and variable high (n=71, 35%).
Patients in the chronic low and variable low Type 2 groups had similar demographics, with two-thirds being Black and 54 and 68%, respectively, having a history of nephritis. The chronic low Type 2 group had stable minimal Type 2 SLE, with an average PSD score of 3.7 that ranged from 2.8 to 4.7. Similarly, these patients had minimal Type 1 SLE activity, with average clinical SLEDAI scores of 0.7. The variable low Type 2 group had higher PSD scores (average: 4.5), ranging from 1.8 to 7.7, as well as higher SLEDAI scores than the chronic low Type 2 group, with ~25% having a SLEDAI ≥8.
Patients in the chronic high and variable high Type 2 groups also had similar demographics with half being Black and two-thirds having no history of nephritis. Additionally, both groups had average SLEDAI scores of 4. Patients in the chronic high Type 2 group had stable high PSD scores ranging on average from 10.3 to 12.7. Patients in the variable high Type 2 group had average scores of 14.1 with a larger range: 10 to 18.5.
Conclusion These findings indicate that patients with lupus differ in their Type 2 SLE activity. One-third of patients had constant high Type 2 activity, and about half had fluctuating Type 2 symptoms. Future studies will determine if this fluctuation is due to inflammation or non-inflammatory etiologies such as perceived stress, extent of social support, PTSD, illness perception, or resilience factors.
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