Pharmacist-led pre-infusion screening using absolute lymphocyte count and neutrophil-to-lymphocyte ratio before immune checkpoint inhibitor therapy: A practice proposal

BackgroundImmune checkpoint inhibitor (ICI) eligibility is primarily guided by tumor-centric biomarkers that do not fully account for the host's systemic immune competence. Emerging evidence suggests that readily available hematologic indices absolute lymphocyte count (ALC) and neutrophil-to-lymphocyte ratio (NLR) are associated with treatment outcomes in patients receiving ICIs, yet these markers are not routinely integrated into pre-treatment assessment.ObjectiveTo propose a structured, pharmacist-led pre-infusion screening approach using ALC and NLR as adjunctive markers of host immune reserve prior to ICI therapy.MethodsA pragmatic traffic-light workflow is described in which oncology pharmacists review complete blood count results within 48 h before infusion and flag patients with lymphopenia or elevated inflammatory indices for clinician reassessment during early ICI cycles.Key FindingsALC and NLR are inexpensive, routinely available biomarkers associated with clinical outcomes in ICI-treated patients. Evidence supporting definitive treatment thresholds remains limited and heterogeneous; the proposed framework should therefore function as a structured prompt for multidisciplinary reassessment rather than a rigid eligibility criterion.ConclusionThe conceptual integration of host immune indices into oncology pharmacy practice is worthy of structured investigation. A pharmacist-led screening workflow may support safer and more deliberate ICI initiation by identifying reversible causes of immune suppression. Prospective validation is required before routine implementation.