Quantitative analysis of brain metabolites in systemic lupus erythematosus patients using multivoxel MR spectroscopy / 中华风湿病学杂志

ABSTRACT

Objective To investigate the metabolite changes in systemic lupus erythematosus (SLE) patients with and without neuropsychiatric symptoms using magnetic resonance spectroscopy (MRS) and explore the associations between image findings and clinical variables. Methods Twenty-two SLE patients with neuropsychiatric symptoms (NPSLE), twenty-one SLE patients without neuropsychiatric symptoms (non-NPSLE) and twenty healthy controls (HCs) underwent routine MRI scan and multivoxel magnetic reson-ance spectroscopy (MVS). The absolute metabolite concentrations were measured bilaterally in the posterior cingulate gyrus (PCG), dorsal thalamus (DT), lentiform nucleus (LN) and posterior paratrigonal white matter (PWM) using LCModel and SAGE software. The relationships between metabolite con-centrations and cognitive function scores were analyzed by Spearman rank correlation. Single-factor Chi-square analysis and t-test were used for analysis. Results ① Compared to control subjects, NPSLE patients had significantly lower N-acetylaspartate (NAA) values in bilateral PCG and DT, with the mean differences of -1.504 [95% confidence interval ( CI) (-2.335, -0.672), P=0.001], -1.460 [95%CI (-2.349, -0.570), P=0.002], -1.259 [95%CI (-1.894, -0.625), P=0.000] and -1.022[95%CI (-1.688, -0.356), P=0.003] for RPCG, LPCG, RDT and LDT, respectively. The concentration of total creatinine were observed to decline in RPCG and RDT, with the mean differences of-1.094 [95%CI (-1.845, -0.342), P=0.003], -0.955 [95%CI (-1.630, -0.280), P=0.006], -1.259 [95%CI (-1.894,-0.625), P=0.006] respectively. Glutamine and glutamate-values decreased significantly in RDT [mean difference=-2.586, 95%CI (-4.139, -1.033), P=0.002]. ② Compared to non-NPSLE patients, NPSLE patients had a lower NAA level in LPCG [mean difference=-1.256, 95%CI (-2.146, -0.367), P=0.006]. Positive correlations between mini-mental state examination scores [RPCG rs=0.312, P<0.05; LPCG rs=0.355, P<0.01], Montreal cognitive assessment scores (RPCG rs=0.362, P<0.01; LPCG rs=0.285, P<0.05) and NAA values in bilateral PCG were detected. Conclusion Both NPSLE and non-NPSLE patients may have metabolite dysfun-ctions in different brain regions. The cognitive disorder in SLE patients may be interpreted by neuronic damage of PCG.