Reference Values and Numerical Ratios of Total Plasma Proteins and Hemoglobin Concentration as Novel Parameters for Blood Donors' Preliminary Eligibility Assessment

Abstract

Background: Blood donors’ eligibility assessment is crucial for ensuring the safety and quality of donated blood, recipients and donor protection. Novel parameters, such as reference values and numerical ratios of total plasma proteins and hemoglobin concentration, may enhance the blood donation screening process. Objective: This systematic review evaluates the utility of reference values and numerical ratios of total plasma proteins and hemoglobin concentration as novel parameters for blood donors' preliminary eligibility assessment. Methodology: A comprehensive literature search was conducted across ten databases namely: PubMed, Scopus, Web of Science, Google Scholar, ScienceDirect, Embase, Cochrane Library, CINAHL, ProQuest, and DOAJ. A total of 450 articles were identified, and after screening, 375 articles met the inclusion criteria. The search terms used included "blood donors," "eligibility assessment," "reference values," "numerical ratios," "total plasma proteins," and "hemoglobin concentration." The search was limited to studies published in English between 2023 and 2025.Data extraction and quality assessment were performed using standardized tools. Results: The analysis of the 375 included studies, encompassing a large cohort of blood donors, revealed significant associations between reference values and numerical ratios of total plasma proteins and hemoglobin concentration and blood donor eligibility. The concentration of total plasma proteins ranges from 7.0 ± 0.4 g/dl to 7.3 ± 0.6 g/dl, and the concentration of hemoglobin ranges from 13.4 ± 0.1 g/dl to 13.7 ± 0.09 g/dl. The numerical ratio of total plasma proteins to hemoglobin concentration ranges from 1.045 ± 0.006 to 1.063 ± 0.008. The findings suggest that these parameters can be useful in predicting donor eligibility and reducing deferral rates. Conclusion: This systematic review highlights the potential of reference values and numerical ratios of total plasma proteins and hemoglobin concentration as novel parameters for blood donor eligibility assessment. The results have implications for improving donor screening processes and increasing the availability of safe blood products.