Abstract :
Introduction: Lipemic samples are affecting sample integrity and may raise questions on accuracy of
test results. To overcome lipemic interference ultracentrifugation, high speed centrifugation, lipid clearing
agent, dilution with normal saline or sample blanking can be used. Out of these, ultracentrifugation is likely
to cause least interference as there is minimal exposure to additional chemicals.
Aims and Objectives: The study was conducted to compare the results obtained for some commonly asked
biochemical parameters, before and after ultracentrifugation and to assess the need of removal of lipemia
using ultracentrifugation as a tool for these parameters.
Materials and Methods: From 50 lipemic samples, 2 aliquots were prepared each having 500 microliter
of serum. Out of these 2, one was used to perform amylase, urea, creatinine, glucose and uric acid.
From Second aliquot, same parameters were performed after ultracentrifugation and comparison of results
obtained, was done by Student’s t-test. Moreover, ratio of % lipemic bias to CLIA criteria, biological
variation and % coefficient of variance of laboratory were also calculated to see whether the difference is
clinically significant too.
Results: Statistically significant difference between lipemic and ultracentrifuge samples was observed
in amylase, urea, creatinine, uric acid and glucose while only glucose and uric acid showed clinically
significant difference.
Conclusion: Lipemia causes statistically significant interference in estimation of amylase, urea, creatinine,
glucose and uric acid and ultracentrifugation is very effective process in removal interference caused
by lipemia. When this statistically significant interference was studied in the light of clinical need,
only glucose and uric acid showed clinically significant interference. Laboratories not equipped with
ultracentrifuge, can use kinetic method, two point kinetic method or at least two reagents method as
alternative.
Keyword :
Amylase, Clinical chemistry, Creatinine, Glucose, Interferences, Urea, Uric acid.