Pos1128 Evaluation of Changes in Sle Patients’ Phenotype at Disease Onset in the Last Forty Years: Preliminary Data of a Single Center Experience

Background: Systemic lupus erythematosus (SLE) is an autoimmune disease associated with a high degree of variability at onset, possibly related to ethnicity, age at onset and gender [1]. At the early stages patients may present typical symptoms or nonspecific findings which makes SLE diagnosis challenging: it is estimated that time between onset of symptoms and SLE diagnosis is about 24 months. [2] However, early recognition of signs or symptoms suggestive of SLE onset and advancement in diagnosis and management may have changed clinical features at onset. Objectives: The aim of this study was to assess whether there have been any changes in clinical manifestations or in epidemiology at SLE onset over the last forty years. Methods: We retrospectively examined 264 medical charts of patients affected by SLE, who reached our Lupus Clinic from 1973 to 2021 and currently in follow up. We divided this cohort, according to the year of SLE diagnosis, in 4 groups: '70-'89, '90-'99, 2000-2009, 2010-2020. We considered as manifestations at the onset of the disease all those signs and symptoms that led the patient to seek medical attention, along with those that appeared during the diagnostic work-up phase. Qualitative variables were compared with Chi-Squared or Fisher's exact test, quantitative variables with one-way Anova or Mann-Whitney test. Results: We have included 264 SLE patients, 255 (96,6%) females, 245 Caucasian (92,8%). The mean age of onset is 29,3 years (±11,83) and the mean age of diagnosis is 31,1 years (±12,03). Mean age of onset, and consequently mean age of diagnosis, has significantly increased in different groups (p-value<0,0001) (Figure 1). In details, the greatest statistical difference (p-value<0,0001) is observed comparing the '70-'89 group and the 2010-2020 group, where the mean age of onset increased from 23,83 (±7,45) years to 35,23 (±13,24). Concerning the clinical presentation at onset, as expected the most frequent symptoms observed were musculoskeletal (80,68%) and mucocutaneous (76,14%). Comparing the four groups, we found a statistically significant reduction in mucocutaneous involvement at onset (p-value=0.0008). Particularly, the greatest statistical difference (p-value=0.0008) is observed comparing the '90-'99 decade and the 2010-2020 group, where the percentage of mucocutaneous symptoms is decreased from 89,58% to 62,19%. Analysing in detail the mucocutaneous pattern in the various groups (Figure 2), a statistically significant reduction in the presence of malar rash and non-scarring alopecia is observed (p-value=0.0070 and 0.0018, respectively). Malar rash decreases from 56,10% in the '70-'89 group to 28,05% in 2010-2020 decade (p-value=0.0024), while non-scarring alopecia is present in 22,92% in the '90-'99 group, and in only 3,26% in the 2000-2009 group (p-value=0.005). Conclusion: In this preliminary cohort we observed a progressive increase in the mean age at the onset of SLE over the years. Nevertheless, this increase does not deviate from the mean age range defined in the literature [1]. The most common initial manifestations of SLE are confirmed to be musculoskeletal and mucocutaneous. However, in our cohort, we have observed that over the last 40 years there has been a change in the phenotype at disease onset, with less mucocutaneous involvement, particularly the malar rash and the non-scarring alopecia. This variation in the clinical presentation could be explained by the shorter diagnostic delay, which has decreased by approximately 6 months compared to the '70-'89 group in the 2010-2020 group. In addition, it could be possible that early recognition of patients with signs and or symptoms possibly related to SLE may have led to use of pharmacological therapy (such as hydroxychloroquine) and/or behavioural interventions (such as photoprotection) at an earlier stage, reducing the rate of mucocutaneous manifestations even at the onset of the disease. Finally, this preliminary data will be reconsidered with the inclusion of the whole cohort of SLE patients. REFERENCES: [1] Sassi Rh et al, Clin Rheumatol 2017. [2] Kapsala et al, Clinical and Experimental Rheumatology 2023. Acknowledgements: NIL. Disclosure of Interests: None declared.