LONGITUDINAL NEUROCHEMICAL CHANGES IN THE HIPPOCAMPUS ASSOCIATED WITH MOOD AND COGNITIVE IMPAIRMENT IN SYSTEMIC LUPUS ERYTHEMATOSUS

O004 / #223 Topic: AS05 - CNS Lupus SCIENTIFIC HYBRID SESSION: CLINICAL TRACK PRESENTATIONS - OUTSTANDING ABSTRACT PRESENTATIONS 23-05-2025 9:00 AM - 10:00 AM Background/Purpose Systemic lupus erythematosus (SLE) is an autoimmune disease with multiorgan involvement. The hippocampus is one of the most thoroughly investigated structures in the brain and hippocampal atrophy was found in SLE patients. Proton magnetic resonance spectroscopy (¹H-MRS) has proved to be a noninvasive tool for detecting neuronal metabolic dysfunction in neurological diseases. The purpose of this study was to investigate the presence of neurochemical changes in the hippocampus in SLE patients using proton magnetic resonance spectroscopic imaging (¹H-MRSI) technique and to determine if clinical, laboratory and treatment features are associated with its occurrences. Methods We included 58 SLE patients (mean age of 39.21±11.49 years, range 20-68) and 58 healthy controls (mean age of 40.91±12.02 years, range 23-66). ¹H-MRSI over the bilateral hippocampus was done with a Philips 3T MRI scanner and signals from N-acetyl-containing compounds (NAA), choline-based compounds (Cho), glutamate (Glu), glutamine (Gln), Glx (the sum of Glu and Gln) and creatine (Cr) to determine NAA/Cr, Cho/Cr and Glx/Cr ratios. After a minimum of 12 months ¹H-MRSI acquisitions were repeated in 58 SLE patients and 51 controls. Neurological manifestations were analyzed according to the ACR classification criteria and SLE disease activity index (SLEDAI). Cognitive impairment was screened using the Montreal Cognitive Assessment (MoCA), symptoms of anxiety (Beck’s Anxiety Inventory - BAI) and depression (Beck’s Depression Inventory - BDI) 4 . BAI scores may range from 0 to 63: minimal anxiety levels (0-7), mild anxiety (8-15), moderate anxiety (16-25), and severe anxiety (26-63) and BDI scores are classified as minimal depression (0-13), mild depression (14-19), moderate depression (20-28), and severe depression (29-63). Results The median score for MoCA was 21.07±4.66. Using a MoCA cutoff score of < 26, total of the 49 patients (87.93%) were identified to have mild cognitive impairment. The median score for BAI was 25.67±14.60 and 46 patients (79.31%) had moderate/severe anxiety symptoms. The median BDI score was 22.88±9.16 and 37 patients (63.79%) had moderate/severe depressive symptoms. We found a significant reduction in NAA/Cr ratios in SLE patients when compared to healthy controls ( p = 0.049) correlated positively with MoCA scores (r=0.432, p =0.001), and negative correlation with BDI scores (r=-0.334, p = 0.010) and associated with use of prednisone during the treatment ( p =0.039). Follow-up study showed a reduction in NAA/Cr ratios ( p =0.042) correlated negatively with BDI scores (r=-0.313, p =0.017), when compared to SLE patient’s baseline values (Table 1). Table 1 Results of comparison of metabolites levels of the bilateral hippocampi in SLE patients and healthy controls Conclusions This is the first longitudinal study to assess levels of metabolic changes in hippocampus in SLE patients using ¹H-MRSI. Metabolic abnormalities in the hippocampus were associated with cognitive impairment, symptoms of anxiety and depression during the treatment. Therefore, NAA/Cr ratios may be used as a surrogate marker in follow-up studies of SLE.