Appropriate Method of TIBC Estimation in Reference to Serum Transferrin Levels

Area of Science:

• Clinical Biochemistry
• Hematology
• Laboratory Medicine

Background:

• Variations in reference ranges exist among current total iron binding capacity (TIBC) estimation methods.
• Serum transferrin (TF) is a sensitive iron status indicator but requires specialized immunoassay equipment.
• Routine biochemistry labs often lack the necessary equipment for direct TF measurement.

Purpose of the Study:

• To compare different methods for estimating TIBC.
• To correlate TIBC values from various methods with serum TF concentrations.
• To identify the most appropriate and reliable TIBC estimation method for routine use.

Main Methods:

• An analytical cross-sectional study involving 250 leftover serum samples.
• Estimation of TIBC using direct, indirect, and calculated (iron + unsaturated iron binding capacity [UIBC]) methods.
• Measurement of serum TF levels for correlation analysis.

Main Results:

• The mean TIBC values were 378.24 µg/dL (direct), 342.23 µg/dL (indirect), and 344.51 µg/dL (calculated).
• Statistically significant differences were observed between the direct method and both indirect and calculated methods.
• A strong positive correlation (r=0.888) was found between the direct TIBC method and serum TF levels.

Conclusions:

• The direct method for TIBC estimation demonstrates superior reliability compared to indirect and calculated methods.
• The direct method shows a strong correlation with serum TF levels, making it a preferred choice.
• This finding supports the direct method's utility in routine biochemistry laboratories for assessing iron status.