The influence of intrathecal injection of methotrexate and dexamethasone on neuropsychiatric systemic lupus erythematosus (NPSLE): a retrospective cohort study of 386 patients with NPSLE

BACKGROUND: Neuropsychiatric involvement is one of the major concerns in systemic lupus erythematosus (SLE). The therapeutic effect of intrathecal treatment of methotrexate and dexamethasone has been investigated in some exploratory studies, but its influence on the long-term prognosis of neuropsychiatric SLE (NPSLE) remains unknown. METHODS: This was a propensity score-matched retrospective study. Outcomes at discharge and time free from NPSLE relapse or death were evaluated by multivariate logistic regression, survival analysis, and Cox regression as appropriate. RESULTS: Among 386 hospitalized patients with NPSLE, the median [IQR] age was 30.0 [23.0–40.0] years, and 342 patients (88.4%) were female. Of those, 194 patients received intrathecal treatment. Patients in the intrathecal treatment group had higher Systemic Lupus Erythematosus Disease Activity Index 2000 scores (median 17 vs. 14 points, IQR 12–22 vs. 10–19 points, P <0 .001) and were more likely to receive methylprednisolone pulse therapy (71.6% vs. 49.5%, P < 0.001) than those who did not receive intrathecal therapy. Intrathecal treatment was associated with a higher probability of survival and being free from NPSLE relapse than control treatment among the 386 unmatched patients (P =0.042 by log-rank test) and within 147 propensity score-matched pairs (P =0.032 by log-rank test). In the subgroup of NPSLE patients with increased levels of protein in cerebrospinal fluid, intrathecal treatment had a positive influence on their prognosis (P < 0.001). CONCLUSIONS: Intrathecal treatment of methotrexate and dexamethasone was associated with a more favorable prognosis of NPSLE and may serve as a valuable additional therapy for NPSLE patients, especially for those with elevated levels of protein in cerebrospinal fluid. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s13075-023-03030-w.