PO:14:201 | Olfactory Assessment in Patients with Systemic Lupus Erythematosus: Correlation with Clinical, Serological, and Imaging Markers

Lorenza Bruno¹, Giacomo Cafaro¹, Marta Di Berardino¹, Roberto Dal Pozzolo¹, Anna Colangelo¹, Francesco Tromby¹, Martina Nicchi¹, Giulia Cruciani¹, Biancamaria Pianese¹, Roberto Gerli¹, Elena Bartoloni Bocci¹, Carlo Perricone¹ | ¹Università degli Studi di Perugia, Italy

Objective: Olfactory dysfunction is a relatively frequent manifestation in patients with systemic lupus erythematosus (SLE). This study aimed to assess the prevalence of olfactory dysfunction in SLE patients, its correlation with clinical, serological, and damage indices, and to investigate microstructural changes of the olfactory tract using diffusion tensor imaging (DTI) fiber tracking. Methods:Thirty-two patients with SLE (ACR 1997 criteria) were enrolled. Clinical history, autoantibody profile, and disease indices (SLEDAI-2K, SLICC/ACR Damage Index) were collected. Olfactory function was evaluated using the Italian Olfactory Identification Test (IOIT), and neuropsychiatric symptoms with the Beck Depression Inventory I (BDI-I). A subgroup of 20 patients underwent brain MRI with DTI and tractography of the olfactory tract, performed on a 3T clinical MRI scanner. Preprocessing was performed with DTIPrep; DTI reconstruction and fiber tracking were conducted using Diffusion Toolkit, and tractography analysis with TrackVis. Parameters extracted included fractional anisotropy (FA), mean diffusivity (MD), radial diffusivity (RD), axial diffusivity (AD), and tract volume. Data were compared with 20 age- and sex-matched healthy controls. IOIT scores were analyzed in relation to clinical and imaging findings.

Results. Olfactory dysfunction (hyposmia) was observed in 40% of SLE patients. IOIT scores correlated significantly with cumulative damage (SLICC; p <0.01)(Fig.1). Trends, though not statistically significant, were observed between hyposmia and both antidepressant use and anti-beta-2 glycoprotein I (anti-B2GPI)antibodies. MRI analysis was feasible in 8 of the 20 MRI-scanned SLE patients. Compared with controls, SLE patients showed a significant reduction in olfactory tract volume (p = 0.007), along with increased FA, MD, RD, and AD values, consistent with microstructural alterations (Tab 1).

Conclusions. this study highlights a high prevalence of olfactory dysfunction in SLE and its association with cumulative organ damage, suggesting hyposmia as a potential clinical marker. Anti-B2GPI antibodies and antidepressant may represent contributing factors. DTI and tractography findings support a central, possibly ischemic or inflammatory, origin of olfactory impairment. These results underscore the relevance of olfactory assessment as a potential indicator of neuropsychiatric involvement and overall disease burden in SLE.

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