CAUSES OF ERRONEOUS RESULTS (INTERFERENCES CAUSING ABNORMAL RESULT) These are listed in Table 809.1 Table 809.1 Causes of erroneous results with hematology analyzer Parameter Interfering factors Erroneous increase Erroneous decrease 0. All parameters — Clotted sample 1. WBC count Nucleated red cells Large platelet clumps Unlysed red cells (some abnormal red cells resist lysing) Cryoglobulins Clotted sample 2. RBC count Very high WBC* Large numbers of giant platelets Clotted sample Microcytic red cells Autoagglutination 3. Hemoglobin Very high WBC Hyperlipidemia High bilirubin Clotted sample 4. MCV Very high WBC Hyperglycemia Autoagglutination (cold agglutinins) Cryoglobulins 5. MCHC Hyperlipidemia Autoagglutination (cold agglutinins) Very high WBC 6. Platelets Microcytic red cells WBC fragments Cryoglobulins Platelet satellitism Platelet clumping *: WBCs are counted along with RBCs, but normally their number is statistically insignificant FLAGGING ‘Flags’ are signals that occur when an abnormal result is detected by the analyzer. Flags are displayed to reduce false-positive and false-negative results by mandating a review of blood smear examination.