Lipemia Interferences in Biochemical Tests, Investigating the Efficacy of Different Removal Methods in comparison with Ultracentrifugation as the Gold Standard

Introduction. As a common interferer in clinical chemistry, lipemic specimens could be a source of significant analytical errors. Ultracentrifugation has been by far the only reliable, but an unavailable and expensive, method to eliminate the lipemic effect. Materials and Methods. Among the daily samples, those with triglyceride >400 mg/dL (4.6 mmol/L) and also turbid were selected, divided into three groups, based on triglyceride concentration, and three pooled serums were made for each group. Then all pooled serums were investigated by using a DIRUI biochemistry analyzer CS-800 for routine chemistry tests in different methods including direct measurement, serum blank, serum dilution, and measurement after ultracentrifugation. Results. According to our study, there were significant differences before and after ultracentrifugation in all lipemic levels and for all parameters except for alanine aminotransferase (ALT), alkaline phosphatase (ALP), bilirubin, and uric acid. Based on allowable inaccuracy for each parameter, calcium, magnesium, phosphorus, total protein, iron, total iron-binding capacity (TIBC), urea, and chloride are being influenced by all lipemic degree and neither serum dilution nor using serum blank is as effective as ultracentrifuge for elimination. Serum blank was a proper method of lipid removal for the measurement of glucose. Conclusion. Lipemia is a well-known interferer in clinical chemistry. One cannot avoid lipemia, but fortunately, severe lipemia is a rare phenomenon in the laboratory, and for assessment of some analytes in a lower degree of lipemia, use of serum blank eliminates the need for ultracentrifuge.

Download Full-text

Serum iron, ferritin, transferrin, total iron binding capacity, hs-CRP, LDL cholesterol and magnesium in children; new reference intervals using the Dade Dimension Clinical Chemistry System

Clinica Chimica Acta ◽

10.1016/j.cccn.2004.01.002 ◽

2004 ◽

Vol 342 (1-2) ◽

pp. 211-217 ◽

Cited By ~ 61

Author(s):

Offie P. Soldin ◽

Laura H. Bierbower ◽

James J. Choi ◽

Jennifer J. Choi ◽

Savannah Thompson-Hoffman ◽

...

Keyword(s):

Serum Iron ◽

Ldl Cholesterol ◽

Binding Capacity ◽

Clinical Chemistry ◽

Reference Intervals ◽

Total Iron ◽

Iron Binding ◽

Total Iron Binding Capacity ◽

Hs Crp ◽

Iron Binding Capacity

Download Full-text

Immunoturbidimetric determination of serum transferrin on a Kone Progress autoanalyser

Journal of Automatic Chemistry ◽

10.1155/s146392468900009x ◽

1989 ◽

Vol 11 (1) ◽

pp. 40-41 ◽

Cited By ~ 2

Author(s):

Luc Cynober ◽

Jacques Le Boucher ◽

Jacqueline Giboudeau

Keyword(s):

Binding Capacity ◽

Clinical Chemistry ◽

Total Iron ◽

Radial Immunodiffusion ◽

Serum Transferrin ◽

Iron Binding ◽

Total Iron Binding Capacity ◽

French Society ◽

Iron Binding Capacity

The Kone Progress, a multiparametric discrete analyser, was used to determine serum transferrin with a kit supplied by Kone. Assays recommended by the French Society of Clinical Chemistry were performed in order to assess the suitability of the test. Repeatability was assessed using serum pools with low (L), medium (M) and high (H) concentrations of transferrin. The coeffcients of variation (CV) were 5.4, 3.2 and 2.0% respectively for 30 determinations (within-batch). Reproducibility on 15 consecutive days (between-batch) was also satisfactory (CV for L = 7.3%, M = 6.3% and H = 3.8%). There was no serum-to-serum contamination. Results correlated closely with those obtained using radial immunodiffusion (RID) (r = 0.942) and total iron-binding capacity (r = 0.954)for 90 determinations.Transferrin measurement by immunoturbidimetry on the Kone Progress emerges as a well-suited, rapid and inexpensive alternative to other time-consuming (RID) and sophisticated (laser immunonephelemeter) techniques.

Download Full-text

Modification of Fully Automated Total Iron-binding Capacity (TIBC) Assay in Serum and Comparison with Dimension TIBC Method

Clinical Chemistry ◽

10.1093/clinchem/48.9.1565 ◽

2002 ◽

Vol 48 (9) ◽

pp. 1565-1570 ◽

Cited By ~ 13

Author(s):

Hachiro Yamanishi ◽

Shigeru Iyama ◽

Yoshihisa Yamaguchi ◽

Yuzuru Kanakura ◽

Yoshinori Iwatani

Keyword(s):

Binding Capacity ◽

Clinical Chemistry ◽

Transferrin Saturation ◽

Original Method ◽

Total Iron ◽

Iron Binding ◽

Total Iron Binding Capacity ◽

Colored Complex ◽

Modified Method ◽

Iron Binding Capacity

Abstract Background: We previously reported the development of a fully automated assay for total iron-binding capacity (TIBC) in serum, using a multipurpose automated analyzer. However, this method requires four different reagents and is thus useful only with a limited number of available analyzers. We simplified our original assay and compared the analytical performance of the modified method with that of a commercial, fully automated TIBC assay (Dimension® TIBC assay). Methods: We simplified our original method to require only three reagents. Calibration was also altered and was performed with human transferrin standard solutions. An advantage of this method is that it does not require separation of excess unbound iron after the first step of transferrin saturation. Unbound iron is eliminated by formation of a complex with the chromogenic reagent ferrozine in the second step. Iron dissociated from transferrin by acidic pH reacts with ferrozine to form a colored complex in the final step, and the increase in absorbance at 570/660 nm is directly proportional to the TIBC measured. TIBC values were determined for 49 healthy individuals and 148 patients with this modified TIBC assay and with a commercial, fully automated TIBC method (Dimension clinical chemistry system), and calculation of TIBC based on the sum of the serum iron and unsaturated iron-binding capacity was performed for 97 patients. Results: The within-run CVs for the modified TIBC assay and the Dimension TIBC assay were <4.8% and <2.4%, and the between-run CVs were 1.2% and 1.7%, respectively. The dilution curves were linear for TIBC values up to at least 180 μmol/L with both methods. TIBC values obtained by our method were linearly correlated with serum transferrin concentrations (r = 0.984; Sy|x = 3.18 μmol/L; P <0.001). The correlation between the values obtained with the present method (y) and those obtained with the Dimension TIBC method (x) was y = 1.04x + 1.19 μmol/L (r = 0.985; Sy|x = 2.47 μmol/L), and with the calculation method (x) was y = 1.18x + 2.62 μmol/L (r = 0.976; Sy|x = 3.27 μmol/L). Conclusions: Our modified, fully automated TIBC assay performed similarly to the Dimension TIBC assay and is adaptable for use with many multipurpose automated analyzers.

Download Full-text