A 33-month old female child presented at a pediatric clinic with acute tonsillitis, and it
was subsequently discovered that she had familial hyperlipidemia. Measurement of the patient’s
whole blood tests was performed by a multiparameter automated hematology analyzer, the CELLDYN
Ruby System® (Abbott, Lake Forest, USA) using venous blood extracted from a tube
containing 3.0 mL of EDTA. Although her hematocrit levels were within normal limits, the
hemoglobin (Hgb) level, mean corpuscular volume (MCH) and mean corpuscular Hgb concentration
(MCHC) could not be determined using the spectrophotometric method. The results of these tests
could not be measured when repeated using dilution. When the sample was left to rest for several
minutes, it was observed to be excessively lipemic. The measurements were repeated using the
Alinity HQ Analyzer® (Abbott), which determines Hgb concentration using laser scatter and
spectrophotometry. Hgb cellular concentration was incorrectly measured as being 21.9 mg/dL using
routine spectrophotometry (denoted by a flag indicating Hgb interference) and correctly found to be
10.8 mg/dL. Thus, in samples of excessive lipemia, Hgb, MCH, and MCHC levels cannot be
measured accurately using spectrophotometry. Hematology analyzers that can measure cellular
hemoglobin (cHGB) and average erythrocyte hemoglobin concentration (cHCM) by laser scatter
method may be recommended when analyzing a blood sample that contains excessive lipemia.
