# Association of plasma ceramide with stroke-associated pneumonia in acute ischemic stroke

## TL;DR

This study finds that plasma ceramide levels are linked to stroke-associated pneumonia in patients with acute ischemic stroke, suggesting a potential new biomarker for predicting this complication.

## Contribution

The study identifies C16:0-Cer as an independent predictor of stroke-associated pneumonia, offering a novel biomarker for early risk assessment.

## Key findings

- Plasma C16:0-Cer, C18:0-Cer, and CERT1 scores are significantly higher in patients with acute ischemic stroke and stroke-associated pneumonia.
- C16:0-Cer is an independent risk factor for stroke-associated pneumonia with moderate predictive accuracy.
- C16:0-Cer levels correlate with stroke severity as measured by NIHSS and mRS scores.

## Abstract

Stroke-associated pneumonia (SAP) is a common and severe complication of acute ischemic stroke (AIS), yet its occurrence remains unpredictable. Post-stroke immune dysregulation and systemic inflammatory responses play a crucial role in susceptibility to SAP, highlighting the need for immune-related biomarkers. Ceramide (Cer) is kind of bioactive sphingolipids involved in inflammatory signaling and immune cell regulation, and has been implicated in infection and inflammatory diseases. This study aims to explore the association between Cer and SAP and evaluate the predictive value for SAP occurrence.

This study retrospectively collected a total of 266 eligible patients with AIS and 93 healthy controls. Demographic and clinical data, as well as the concentrations of plasma C16:0-Cer, C18:0-Cer, C24:1-Cer, and C24:0-Cer, were obtained from medical records and were compared before and after propensity score matching. The least absolute shrinkage and selection operator (LASSO) regression was utilized to select variables, and risk factors were detected by multivariate analysis. The predictive values were evaluated by receiver operating characteristic curves.

The levels of C16:0-Cer, C18:0-Cer, C24:1-Cer, C24:0-Cer and Coronary Event Risk Test 1 (CERT1) score were higher in patients with AIS than healthy controls, in which C16:0-Cer, C18:0-Cer and CERT1 score significantly elevated in SAP patients compared with non-SAP patients. Patients with minor ischemic stroke had lower levels of C16:0-Cer, C18:0-Cer and CERT1 score with those with moderate and severe ischemic stroke. Meanwhile, levels of C16:0-Cer, C18:0-Cer and CERT1 score were positively correlated with the National Institutes of Health Stroke Scale (NIHSS) and modified Rankin scale (mRS) score. The A2DS2 score, C16:0-Cer, high-sensitivity C-reactive protein, and neutrophil-to-lymphocyte ratio were identified as independent risk factors for SAP. C16:0-Cer exhibited a predictive value with an area under curve of 0.725, sensitivity of 74.0%, and specificity of 61.2% for SAP.

Plasma C16:0-Cer, C18:0-Cer, and CERT1 scores were significantly elevated in patients with AIS and SAP. Among them, C16:0-Cer served as an independent predictor for SAP in AIS patients. It demonstrated moderate predictive accuracy, suggesting its potential as a novel biomarker for early SAP risk stratification.