Background/Purpose: Many neurologic and neurodegenerative abnormalities are first demonstrable in the olfactory system with loss of smell up to 10 years before the onset of cognitive or motor dysfunction. The aim of this follow-up study was to assess the prevalence and progression of olfactory disorder in SLE compared with healthy controls, to correlate with presence of neuropsychiatric manifestations, disease activity, presence of Anti-P and limbic structure volume reduction during 3 years follow-up.

Methods:  Consecutive SLE patients were enrolled in this study. The control group was consisted by age and sex matched healthy individuals. Neurological manifestations were analyzed according to the ACR criteria. SLE patients were further assessed for clinical and laboratory SLE manifestations, disease activity (SLEDAI), and damage (SDI). Anti-P was performed by ELISA. Olfactory functions were evaluated using the Sniffin’ Sticks test, in 3 stages (TDI). We measure the volumes of the amygdala and hippocampus by MRI scans 3T Phillips scanner. Volumes were processed using FreeSurfer® software. Clinical, laboratory evaluation, the volumes of the amygdala (AG) and hippocampus (HC), olfactory functions and Anti-P was performed every year for 3 year for each patients. p<0.05 was considered significant.

Results: We included 83 SLE patients (91.5% female; mean age 39.6 years; SD±11.1 years) and 60 healthy volunteers (90.1% female; mean age 38.6 years; SD±13.3 years) (p>0.05). Olfactory changes were observed in 44 (53.0%) SLE patients and in 18 (30.0%) controls (p=0.001). SLE patients had significantly lower mean in all three phases (TDI) of the olfactory assessment [mean of 29.04 (SD ± 5.13)] when compared with healthy volunteers [mean of 31.35 (SD ± 4.24)] (p=0.004) and decrease in the sense of smell was correlated with age (p=0.002; r= -0.331), anxiety (p=0.008; r= -0.291), depression (p= 0.005; r= -0.308) and index damage (p= 0.018; r= -0.268). We also observed an association between olfactory changes and SDI (p=0.049), photosensitivity (p=0.038) and leukopenia (p=0.002). Not significant decrease of smell was observed in the follow-up (p>0.05). Limbic structure volume reduction were not associated with olfactory changes (p>0.05).We did not observed significant decrease in the limbic structures volume between patients [median mm^3: AG 3500.61; HC 7831.64] and controls [AG 3350.62 (p=0.272); HC 7391.65 (p=0.234)]. The decrease of the limbic volumes in patients was not significant in the follow-up [median AG volume mm³: T₁ 3500.61 (p=0.16); T₂ 3508.94 (p=0.12); and T₃ 3461.01 (p=0.19)] [median HC volume mm³: T₁ 7831.64 (p=0.32); T₂ 7680.85 (p=0.23); and T₃7911.19 (p=0.27)]. Anti-P were identified exclusively in SLE patients and were present in 14 (10.8%) of them in the first assessment and remained positive in the two following annual assessments (p<0.001). Anti-P was associated with decrease left amygdala volume in the second assessment (T₂) (p=0.016) and not associated with decrease of smell (p=0.390), CNS involvement (p= 0.713) or psychosis (p= 0.076).

Conclusion: Smell deficiency has been suggested to be an early and predictive sign in several CNS diseases, and therefore, might be a useful and easy tool for the physician in early diagnosis of CNS involvement in autoimmune disease.

« Back to 2016 ACR/ARHP Annual Meeting

ACR Meeting Abstracts - https://acrabstracts.org/abstract/alterations-in-sense-of-smell-and-limbic-structures-in-patients-with-systemic-lupus-erythematosus-during-3-years-follow-up/