Effect of interference from hemolysis, icterus and lipemia on routine pediatric clinical chemistry assays

Clinical laboratory assays can be affected by interferents like hemoglobin (Hb), lipids and bilirubin. We evaluated the effect of these interferences on pediatric samples for different chemistry assays. Further we established cut-off indices above which these interferences confound sample results.

Three separate serum pools were spiked with increasing concentrations of hemolysate or intralipid or bilirubin and different analytes were analyzed. The Hemolysis-(H), Lipemia-(T) and Icterus-(I) indices were measured on Vitros 5600. Analytes affected by lipemia were treated with LipoClear ® and re-analyzed. All the measured analytes were compromised by gross hemolysis (H-Index >1000).

Except lipase and magnesium (Mg(++)), all other analytes were affected by moderate (H-Index >250) and significant hemolysis (H-Index >500). Low estradiol levels showed a significant effect at severe icterus (I-Index >20.0). C3, C4, Ceruloplasmin, Haptoglobin, Immunoglobulins (Ig) and Vitamin D were significantly affected by moderate (T-Index >100) and severe (T-Index >500) lipemia. LipoClear ® treatment significantly attenuated the lipemic interference on the above analytes except for C3, C4, and IgG.

Accurate reporting of pediatric samples for the analytes affected by common interferences will lead to better clinical interpretation.