Reference Values and Numerical Ratios of Total Plasma Protein and Hemoglobin Concentration among Apparently Healthy Prospective Blood Donors in Calabar Municipality, Cross Rivers State, Nigeria: A Comparative Study using Three Hemoglobinometers

Background: Despite recent development and improvement made on blood donor’s eligibility assessment and screening profile for blood donation, it is only in the last three decades that researchers in the primary, secondary, tertiary, federal and national levels have observed an unprecedented increase in blood donor’s disqualification, rejection, and deferment .This may have been hypothesized to be caused by apparently low hemoglobin concentrations or false high hemoglobin concentrations thus leading to false acceptance of blood donors. This may also happen due to the effects of total plasma proteins.

Objective: This study aimed at determining the reference values and ratios of total plasma protein (TPP) levels and hemoglobin (Hb) concentration analyzed using three different types of hemoglobinometry methods in prospective blood donors recruited within Calabar Municipality, Nigeria.

Methodology: This cross-sectional one-year study (2021-2022) employed an experimental design with randomized simple sampling and purposeful sampling techniques. Participants (n = 430, 230 males, 200 females aged 20-60 years) completed an opened-ended, semi-structured self-administered questionnaire form after providing informed / written consent. Blood samples were analyzed for TPP levels using Biuret’s spectrophotometric method, Hb concentration using Cyanmethemoglobin (HICN) method, Packed cell volume (PCV) using Micro-hematocrit, and specific gravity using copper sulphate (CuSO4) gravimetric method).

Results: The mean TPP levels were 7.59 ± 0.83 g/dl (total), 7.71 ± 0.88 g/dl (male), and 7.48 ± 0.79 g/dl (female) with control sample of 7.70 g/dl. Mean Hb concentrations were 13.53 ± 1.91 g/dl (total), 14.43 ± 1.92 g/dl (male), and 12.77 ± 2.20 g/dl (female) with mean control sample value of 15 ±2.5 g/dl.The mean micro-hematocrit value in (%) were 39.16 ±8.34 , 43.51 ± 4.74 , and 41.36 ±6.73 for female, male and total participants respectively, and with control standard sample value of 45%.Mean specific gravity value using copper sulphate solution (female, male and total participants) were 1.055 ±0.009 (12.5 ±10 g/dl of Hb equivalent),1.058 ± 0.006 (equivalent to 13.60 ± 0.07g/dl of Hb), and 1.057 ± 0.0075 (equivalent to 13.50 ± 0.095 g/dl of Hb) respectively with mean control standard sample value of 1.058 (equivalent to 13.6 g/dl of Hb).The mean TPP: HICN Ratio, TPP: PCV Ratio and TPP: CuSO4 ratio for all three methods were = 0.55. While the total mean HICN:TPP ratio, PCV: TPP, CuSO4: TPP ratio, for all three methods were 1.7- 1.9. There was no statistically significant difference between total, male and female genders respectively (p >0.05).

Conclusion: This study demonstrates that variations in TPP levels which can lead to inaccurate Hb concentration measurements, thus resulting in unnecessary acceptance or disqualification of blood donors. Understanding the reference range and ratio of TPP levels to Hb concentration is crucial for improving blood donor eligibility assessment and blood donor screening profile .