The value of the CRP-albumin-lymphocyte index (CALLY index) as a prognostic biomarker in acute ischemic stroke

Abstract

This study aims to evaluate the predictive capability of CRP-albumin-lymphocyte (CALLY) index in relation to hemorrhagic transformation (HT) and functional outcome in acute ischemic stroke (AIS). A total of 439 AIS patients were included in this analysis. Multivariate logistic regression was conducted to examine the relationship between the CALLY index, HT, and functional outcomes. To address its non-linear association, a restricted cubic spline (RCS) model identified an optimal threshold for the CALLY index. Subgroup analyses further explored the association between the CALLY index and HT. The receiver operating characteristic (ROC) curve, the net reclassification index (NRI), and the integrated discrimination index (IDI) were used to assess and compare the predictive performance of the CALLY index with established models for HT. Furthermore, mediation analysis was performed to elucidate the causal pathways linking the CALLY index, HT, and functional outcomes. Among the participants, 9.79% (43/439) experienced HT, and 49.32% (182/369) encountered adverse outcomes. A higher CALLY index was associated with a lower risk of developing HT (OR 0.449, 95% CI 0.283-0.713) and poor outcome (OR 0.691, 95% CI 0.558-0.855). RCS curves demonstrated an increased risk of HT when the CALLY index fell below 1.188. Compared to existing HT prediction models, the CALLY index demonstrates superior predictive performance, with an AUC of 0.746. Furthermore, the CALLY index exhibits improved reclassification ability, as indicated by enhanced NRI and IDI values. The CALLY index independently predicts HT and adverse outcomes in AIS, demonstrating superior accuracy to existing risk scores and offering a practical biomarker for clinical prognosis.

Keywords: Hemorrhagic transformation; Immunity; Inflammation; Prognosis; Stroke.

Fig. 1

The flowchart of study patients’ inclusion. CRP, C-reactive protein; HT, hemorrhagic transformation.

Fig. 2

The RCS curve of the association between CALLY and HT among AIS population. The analyses have been adjusted potential confounders, including age, sex, hypertension, diabetes mellitus, atrial fibrillation, platelets, NIHSS score on admission, and IVT therapy. The red solid line represents the adjusted ORs, while the shaded light pink areas indicate the corresponding 95% CI. CALLY index could increase the risk of HT when lower than 1.188. RCS, restricted cubic spline; CALLY, C-reactive protein–albumin–lymphocyte; HT, hemorrhagic transformation. OR, odds ratio; CI, confidence interval.

Fig. 3

The distribution of 3-month mRS scores in different quartiles of CALLY among individuals with AIS. CALLY, C-reactive protein–albumin–lymphocyte; mRS, the modified Rankin Scale; AIS, acute ischemic stroke.

Fig. 4

The ROC value of CALLY index, HTI score, HeRS score, HAT score, SEDAN score, SPAN–100 score, GRASPS score in predicting HT in AIS patients. ROC, the receiver operating characteristic; AUC, area under curve; CALLY, C-reactive protein–albumin–lymphocyte; HTI, the Hemorrhagic Transformation Index score; HeRS, Hemorrhage Risk Stratification score; SPAN-100, Stroke Prognostication using Age and NIHSS score; GRASPS, GWTG-Stroke sICH risk score; HAT, Hemorrhage After Thrombolysis score; SEDAN, Symptomatic Intracranial Hemorrhage after Stroke Thrombolysis score.

Fig. 5

The ROC value of CALLY, HTI score, HeRS score, HAT score, SEDAN score, SPAN–100 score, GRASPS score in predicting functional outcome in AIS patients. ROC, the receiver operating characteristic; AUC, area under curve; CALLY, C-reactive protein–albumin–lymphocyte; HTI, the Hemorrhagic Transformation Index score; HeRS, Hemorrhage Risk Stratification score; SPAN-100, Stroke Prognostication using Age and NIHSS score; GRASPS, GWTG-Stroke sICH risk score; HAT, Hemorrhage After Thrombolysis score; SEDAN, Symptomatic Intracranial Hemorrhage after Stroke Thrombolysis score.