Prognostic value of the platelet-to-lymphocyte ratio for outcomes of stroke: a systematic review and meta-analysis.

OBJECTIVE The current study aimed to conduct a systematic literature search and pool data from individual studies to assess the relationship between platelet-lymphocyte ratio (PLR) and functional outcomes and mortality in stroke patients. MATERIALS AND METHODS The databases of PubMed, Embase and Google Scholar were searched for relevant studies up to 21st August 2021. Odds ratios (OR) with 95% confidence intervals (CI) were calculated for the association between PLR and poor functional outcomes and mortality. RESULTS Sixteen studies were included in the systematic review and nine in the meta-analysis. On analysis of eight studies, we noted no statistically significant relationship between PLR and poor functional outcomes in patients with stroke (OR: 1.00 95% CI: 1.00, 1.00 I2=80% p=0.30). Data on mortality was reported by just two studies. Pooled analysis indicated no statistical relationship between PLR and mortality in patients with stroke (OR: 1.49 95% CI: 0.56, 3.98 I2=76% p=0.43). Descriptive analysis of the remaining studies demonstrated conflicting results for the relationship between PLR and early neurological deterioration (END) and functional outcomes. CONCLUSIONS Our results indicate that PLR may not be a useful prognostic marker to predict functional outcomes after AIS. Evidence on the predictive power of PLR for mortality and END after stroke is scarce and contrasting. There is a need for further studies assessing the role of PLR in predicting outcomes of stroke patients while taking into account important confounders like baseline stroke severity and treatment modality.