Interlaboratory standardization of glycated hemoglobin determinations.

Area of Science:

• Clinical Chemistry
• Analytical Chemistry
• Laboratory Medicine

Background:

• The clinical importance of glycated hemoglobin (gHb) measurements necessitates consistent results across different laboratories and assay methods.
• Variability in gHb values can impact patient diagnosis and treatment, particularly for diabetes management.

Purpose of the Study:

• To evaluate the feasibility of standardizing glycated hemoglobin (gHb) measurements between laboratories.
• To assess the accuracy of interlaboratory standardization using a defined reference method.

Main Methods:

• A high-performance liquid chromatography (HPLC) method was established as the reference standard for glycated hemoglobin (gHb) measurement.
• Erythrocyte hemolysates from diabetic and non-diabetic individuals were prepared and used as gHb standards, with values assigned by the HPLC reference method.
• A clinical laboratory utilized commercial ion-exchange and affinity chromatography methods, constructing standard curves for gHb assay.
• Samples analyzed in the clinical laboratory were cross-referenced with the research laboratory's HPLC measurements to validate standardization accuracy.

Main Results:

• Excellent correlation (r = 0.99) was observed between the gHb values obtained using the clinical laboratory's methods and the reference HPLC method.
• No significant differences were found between the gHb values derived from standard curves and those directly measured by the reference method.
• The results confirm the accuracy of the interlaboratory standardization procedure.

Conclusions:

• Interlaboratory standardization of glycated hemoglobin (gHb) measurements is achievable.
• The proposed standardization method ensures accurate and comparable gHb results across different laboratory settings.
• Standardized gHb testing enhances clinical utility and reliability in patient care.