Abstract
PURPOSE: The neutrophil-to-lymphocyte ratio (NLR), monocyte-to-lymphocyte ratio (MLR), platelet-to-lymphocyte ratio (PLR), and systemic immune-inflammatory index (SII) are biological indicators that reflect the inflammatory state in some immune diseases. This study investigated the associations of the NLR, MLR, PLR, and SII with the severity and prognosis of autoimmune glial fibrillary acidic protein astrocytopathy (GFAP-A). PATIENTS AND METHODS: This retrospective study analyzed the data of 62 patients with GFAP-A at the First Affiliated Hospital of Zhengzhou University from January 2020 to August 2024. The Clinical Assessment Scale for Autoimmune Encephalitis (CASE) was used to assess the disease severity at admission and patients were categorized into mild (CASE ≤4) or severe (CASE ≥5) groups. The modified Rankin Scale (mRS) was used to assess the patients' conditions at discharge and follow-up. Patients were categorized into the good (mRS ≤2) or poor (mRS ≥3) prognosis groups at 1-year follow-up. Risk factors affecting the severity and prognosis of GFAP-A were analyzed using binary logistic regression analysis. RESULTS: The NLR, MLR, PLR, and SII were significantly higher in the severe group than in the mild group. The NLR (OR=1.238, 95% CI: 1.003-1.473, P=0.01) was an independent risk factor for the severity of GFAP-A and was positively correlated with the CASE score (r=0.365, P=0.003). The best cut-off NLR for predicting the severity of GFAP-A was 3.05, with a sensitivity of 80%, specificity of 57.1%, and AUC of 0.729 (95% CI: 0.600-0.858, P=0.004). The mRS score at discharge (OR=7.966, 95% CI: 1.120-56.658; P=0.038) was an independent risk factor for poor prognosis one year after discharge. In addition, the NLR, MLR, PLR, and SII at admission and reduction of the PLR after immunotherapy were not associated with patient prognosis (P > 0.05). CONCLUSION: The NLR, an objective, inexpensive, and clinically accessible biomarker, is positively associated with the CASE score, that is, with the severity of GFAP-A. Therefore, the NLR can be used to identify patients with potentially severe GFAP-A at an early stage, thus optimizing the clinical treatment decisions.