Simple Method Corrects Automated Hemoglobin Measurement Interference

By LabMedica International staff writers
Posted on 30 Oct 2013

Image: Normal blood sample on the left and blood sample containing high triglycerides on the right (Photo courtesy of Prof. Tisha Joy, MD).

Hypertriglyceridemia is a well-known factor that can interfere with the measurement of hemoglobin (HGB) using automated hematology analyzers and it can cause falsely high HGB values.

A simple but effective correction method has been introduced to rectify the interference of high blood triglyceride (TG) levels in measurement of blood HGB by automated hematology analyzers commonly used in clinical laboratories.

Clinical laboratorians at the Sichuan University (Chengdu, China) analyzed 50 whole blood samples and 50 plasma samples containing variable TG concentrations. Complete blood cell counts (CBCs) were performed by an XE-2100 automated hematology analyzer (Sysmex; Kobe, Japan) for 102 blood samples, in which high-level TG were artificially added. The same blood samples were centrifuged at different speeds to separate the plasma from blood cells. An optimal centrifugal force and time were identified to separate plasma and blood cells and to exert the least influence on the chylomicrons (CMs) in the plasma, which was then analyzed.

By using the two CBC results, a correction formula was established to calculate the corrected HGB, mean corpuscular hemoglobin (MCH) and mean corpuscular hemoglobin concentration (MCHC) values. Comparisons were also made of HGB, MCH, and MCHC values before and after correction of in-patient individuals who received intralipid and developed lipemia. The percentage differences between the corrected and true values of HGB, MCH and MCHC were −0.28%, 0.06%, and −0.31%, respectively. The correlation coefficients of corrected values versus true values of HGB, MCH, and MCHC were 0.989, 0.935, and 0.717, respectively. This correction method was also effective for native lipemic samples.

The authors concluded that by adding a simple step of low-speed centrifugation, their method was able to provide reliable results of HGB, MCH, and MCHC in highly lipemic blood samples without special equipment. This provided evidence that the HGB concentration of intralipid and plasma mixture was not affected by different centrifugal conditions. Therefore, they recommended that the least time-consuming centrifugation parameter be adopted. The study was published on September 13, 2013, in the Journal of Clinical Laboratory Analysis.

Related Links:
Sichuan University
Sysmex