Feasibility of blood count-derived inflammatory ratios in predicting haemorrhagic transformation and early functional outcomes after intravenous thrombolysis for ischaemic stroke

Introduction
Accurately stratifying the risk of poor outcomes after acute ischaemic stroke remains a critical challenge. Complete blood count (CBC)-derived indices, such as the neutrophil-to-lymphocyte ratio (NLR), have been proposed as prognostic markers. However, their performance compared to other recently proposed CBC-based parameters, including the derived neutrophil-to-lymphocyte ratio (dNLR) and neutrophil-to-lymphocyte-and-platelet ratio (NLPR), remains unclear.

Material and methods
A retrospective analysis of records from 202 patients with acute ischaemic stroke treated with intravenous thrombolysis (IVT) was performed. NLR, dNLR, NLPR and six other novel inflammatory indices – lymphocyte-to-monocyte ratio (LMR), platelet-to-lymphocyte ratio (PLR), mean platelet volume to platelet count ratio (MPR), systemic inflammatory index (SII), systemic inflammation response index (SIRI), and aggregate index of systemic inflammation (AISI) – were calculated from the CBC acquired upon admission and one day after IVT. Differences in laboratory parameters and ratios between groups of diverse outcomes were tested, and diagnostic performance between ratios was compared using multivariate logistic regression models.

Results
Three inflammatory ratios (NLR, dNLR, NLPR) measured the day after IVT were found to be independent risk factors for a poor functional outcome at discharge. The upper quartile of NLR and dNLR alone presented similar performance (OR = 4.04, 95% CI: 2.06-7.92, p < 0.001; sensitivity 40%, specificity 86%, AUC = 0.63). However, dNLR showed higher discrimination value in the combined model with pre-mRS and NIHSS (OR = 5.50, 95% CI: 2.02-14.93, p < 0.001; sensitivity 81%, specificity 93%, AUC = 0.929). This parameter, along with glucose levels, was also associated with the risk of early intracranial bleeding (OR = 4.74, 95% CI: 1.24-18.21, p = 0.023).

Conclusions
In this exploratory study, dNLR measured on the day after IVT was superior to NLR and other parameters in prognosis of unfavourable outcomes and recognition of intracranial haemorrhage. Nevertheless, clinical data such as pre-mRS and NIHSS combined remain the most important predictors.