Many laboratories perform Hb, RBC, and WBC determinations on electronic particle counting instruments. In certain cases, artifacts may falsely alter results.
When WBC counts are substantially greater than 50,000/cu mm, the Hb, Hct, RBC, MCV, and MCH values may be falsely increased unless corrective measures are taken (the word “increase” as used here means increase from true values, which may or may not place the values outside of reference limits).
Peripheral blood nucleated RBCs in substantial numbers will produce false increases of the WBC count unless manually corrected.
Marked hyperlipidemia (>2,000 mg/dl of triglyceride) may increase Hb, MCH, and MCHC values.
High titers of cold agglutinins may decrease the Hct and RBC count and increase MCV, MCH, and MCHC values. However, not all counting instruments react the same to cold agglutinins.
Cryoglobulins may falsely increase the WBC count.
Marked erythrocytosis may falsely decrease the RBC count and the Hct value from true levels and falsely elevate MCH and MCHC values.