Correlation between neurofilament, HMGB1, MMP9, ds DNA blood levels and cognitive impairment in patients with neuropsychiatric systemic lupus erythematosus.

Background: Diagnosis of neuropsychiatric systemic lupus erythematosus (NPSLE) is challenging due to nonspecific biomarkers. High serum levels of neurofilament protein light subunit (NFL), high mobility group box 1 (HMGB1), Matrix metalloproteinase-9 (MMP-9) and have been reported in several autoimmune diseases. The aim of this study was to examine whether their plasma levels could serve as a diagnostic or prognostic biomarker for NPSLE.

Methods: There were 90 SLE patients enrolled in this cross-sectional study (87.8% women and 12.2% men with a mean age of 41.67±11.05 years). We assessed the mental status of patients, also we measured the Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K) and Systemic Lupus International Collaborating Clinics/ACR (SLICC/ ACR) Damage Index or SDI scores. Serum levels of NFL, HMGB1, MMP9, and ds-DNA were investigated to find a role in the pathophysiology of NPSLE.

Results: Among the 90 patients with SLE, 63 (70%) met the criteria of NPSLE syndrome. Our results have shown a notable difference concerning SEDIAC-2k score, SDI score, PANS, MoCA, and Beck anxiety depression, between the two groups (p < 0.05). Although serum level of all measured serum biomarkers (NFL, MMP-9, HMGB1, dsDNA) were higher in patients with NPSLE, the difference was not statistically significant. Interestingly, our results showed that the serum level of NFL was correlated with the serum level of HMGB-1 and MMP-9. (r: 0.411, P=0.003).

Conclusion: Serum level of NFL, HMGB-1 and MMP-9 may be used to detect abnormal mental status in patients with SLE.