Background: Systemic Lupus Erythematosus (SLE) is a chronic autoimmune disorder which displays a great variability in terms of clinical and immunological presentation. The risk of infections in adult patients with SLE is higher when compared to the general population; however, only few studies have hitherto tried to assess a direct correlation between infectious events, initial disease activity and a possible increase of the Safety of Estrogen in Lupus National Assessment - Systemic Lupus Erythematosus Disease Activity Index (SELENA-SLEDAI) in patients with SLE.

Objectives: To assess and evaluate possible correlations between infectious events, initial disease activity and a the increase of the SELENA-SLEDAI in patients with SLE

Methods: A monocentric retrospective study was performed by using real-world data; one hundred forty-two patients (N=142) were enrolled and evaluated as per exclusion criteria. Patients with non-adherence to treatment were also excluded as to avoid possible biases. An assessment of their infectious events was performed, namely the moderate-to-severe infections (Figure 1), as well as their disease activity at the time of diagnosis; subsequently, they were compared with a potential increase in disease activity allegedly occurred in the following 6-to-12 months by using the SELENA-SLEDAI.

Simple linear regressions were used to calculate the correlation between each parameter and the SELENA-SLEDAI with a 95% confidence interval (CI); lastly, a multiple linear regression was performed to assess the global correlation with both parameters.

Results: One hundred and twenty-three (n=123) patients met the inclusion criteria (Figure 2); among these, 86.99% were female (107 patients) and 13.01% (16 patients) were male.

The simple linear regression between infectious events and SELENA- SLEDAI showed a R2 = 29.46% (p < 0.0001, y = 2.3552x + 2.3058, Figure 3); a weaker regression was observed with the initial disease activity as its R2 was 16.12% (p=0.006, y = 0.6212x + 2.9239, Figure 4). Lastly, a multiple linear regression was performed as it showed a R2 of 38.68% (p=0.0001, y= 2.0998x1 + 0.4788x2 + 1.5901.

Conclusion: In this preliminary study, real-life data proved to be essential in assessing the impact of both infections and initial disease activity on the risk of flares among patients affected by Systemic Lupus Erythematosus; the former proved to have a noticeable correlation with an increase of SELENA-SLEDAI in the 6-to-12 months after the event; on the other hand, the initial disease activity showed a less meaningful, albeit significant, association with an heightened disease activity as well as flares.

This study has some limitations (limited number of enrolled patients, different definition of infective events) which need further evaluations to be properly assessed).

REFERENCES: NIL.

Acknowledgements: NIL.

Disclosure of Interests: None declared.