Researchers from Canada have identified the blood neutrophil to lymphocyte ratio (NLR) as an independent predictor of transplant-free survival in pulmonary arterial hypertension (PAH)—particularly in females.
“We reported a potential sexual dimorphism in the ability of NLR to predict mortality in PAH, emphasizing the importance of considering sex-related differences in the development biomarkers in PAH,” the authors wrote.
Jutras-Beaudoin et al found a significantly higher NLR in PAH patients who died or were referred for transplantation when compared with patients with transplant-free survival (P =.0319). However, gender analysis showed that NLR predicted transplantation-free survival only in females.
Through ROC curve analysis, they identified an NLR threshold of 4.8 to discriminate disease severity and risk of death/transplant (AUC, 0.64, P =.03). Patients with high NLR (ie, ≥4.8) presented with a significantly poorer outcome during a median follow-up period of 1154 days. These patients were older and had increased disease severity and lower lung function when compared with those in the low NLR group.
The authors of the study reported 1-, 3-, and 5-year transplant-free survival rates of 65.2%, 21.3.4%, and 10.6% for high NLR patients, respectively. The estimates increased to 86.8%, 72.7%, and 57.6% in the low NLR group.
Regarding PAH subtypes, NLR was higher in patients with scleroderma-associated PAH patients than in patients with idiopathic PAH (P =.0135). Moreover, IPAH and connective tissue disease PAH patients with NLR above the threshold showed a lower survival compared to patients with low NLR.
The authors, from the Centre de Recherche de l’Institut Universitaire de Cardiologie et de Pneumologie de Québec (CRIUCPQ), did not find any association between PAH subtype and transplant-free survival, but NLR remained an independent predictor of survival when corrected for PAH type.
Jutras-Beaudoin N, Toro V, Lajoie AC, Breuils-Bonnet S, Paulin R, Potus F. Neutrophil-lymphocyte ratio as an independent predictor of survival in pulmonary arterial hypertension: an exploratory study. CJC Open. Published online November 29, 2021. doi:10.1016/j.cjco.2021.11.010