ERRORS ENCOUNTERED IN SOME HEMATOLOGY TESTS

Question 1

WBC > 100,000/uL, large (giant) platelets

Answer 1

Falsely high RBC count

Question 2

Autoagglutination, cold agglutinins, hemolysis, microcytosis, schistocytes, clotting

Answer 2

Falsely low RBC count

Question 3

Autoagglutination, high WBC(>50, 000/uL), cold agglutinins, old specimen, hyperosmolar state, reduced cell deformability

Answer 3

Falsely high MCV

Question 4

Cryoglobulin, cryofibrinogen, giant platelets, hemolysis, swollen red cells

Answer 4

Falsely low MCV

Question 5

Lipemia, icterus, chylomicrons, high WBC, spuriously low RBC

Answer 5

Falsely high MCH

Question 6

Spuriously low Hb, falsely high RBC

Answer 6

Falsely low MCH

Question 7

Cold agglutinins, autoagglutination, clotting, hemolysis in vivo and in vitro, spuriously high Hb, falsely low Hct

Answer 7

Falsely High MCHC

Question 8

High WBC, falsely low Hb, spuriously high Hct

Answer 8

Falsely Low MCHC

Question 9

Lipemia, icterus, chylomicrons,chylomicrons, lysis-resistant RBCs with abnormal Hbs, WBC > 20, 000/uL, platelet count(>70, 000/uL), parenteral nutrition, hypergammaglobulinemia, cryoglobulin, cryofibrinogen, hemolysis, heparin, hyperbilirubinemia

Answer 9

Falsely High Hb

Question 10

Clotting

Answer 10

Falsely Low Hb

Question 11

Dehydration, hemoconcentration, insufficient centrifugation, buffy coat inclusion, hyponatremia, plasma trapping

Answer 11

Falsely High Hct

Question 12

Hemolysis, improper sealing of the capillary tube,tube increased anticoagulant concentration, introduction of excess tissue fluid, hypernatremia

Answer 12

Falsely Low Hct

Question 13

Cryoglobulin, cryofibrinogen, giant platelets, high WBC, hyperglycemia

Answer 13

Falsely High Hct automated

Question 14

autoagglutination, clotting, hemolysis, microcytic red cells

Answer 14

Falsely Low Hct automated

Question 15

Lysis-resistant RBCs with abnormal Hbs, nucleated RBCs, megakaryocyte fragments, micromegakaryoblasts, platelet clumps, giant platelets, cryoglobulins, cryofibrinogen, heparin, monoclonal proteins

Answer 15

Falsely High WBC

Question 16

Leukemia, leukoagglutination, clotting, smudge cells

Answer 16

Falsely Low WBC

Question 17

Neutrophil aggregation, neutrophil with hemosiderin granules

Answer 17

Falsely Low neutrophils

Question 18

Nucleated red cells, giant platelets, platelet clumps, malarial parasites, hypolobated neutrophils

Answer 18

Falsely High lymphocyte

Question 19

Large reactive lymphocytes, lymphoblasts, lymphoma cells, immature granulocytes

Answer 19

Falsely High monocyte

Question 20

Neutrophil with hemosiderin granules, red cells with malarial pigments

Answer 20

Falsely High eosinophils

Question 21

Leukemia, fragmented red cells, microorganisms, cryoglobulins, cryofibrinogen, hemolysis in vitro and in vivo, microcytic red cells, red cell inclusions, white cell fragments

Answer 21

Falsely High Platelet count

Question 22

Platelet clumps, old specimen, partial clotting, giant platelets, platelet satellitism, cold agglutinins, clotting, heparin

Answer 22

Falsely Low Platelet count

Question 23

Old specimen, detemining the value too early in an EDTA specimen

Answer 23

Falsely High MPV

Question 24

Critical values of: Hematocrit

Answer 24

<21%; >65%

Question 25

Critical values of: Hemoglobin

Answer 25

<70g/L; >200g/L

Question 26

Critical values of: reticulocyte

Answer 26

> 20%

Question 27

Critical values of: WBC

Answer 27

<2,000/uL
>50, 000/uL

Question 28

Critical values of: blood smear

Answer 28

Neutrophilic phagocytosis of microorganisms, shows abnormal leukemoid reaction, schistocytes, blast forms, presence of intracellular organisms

Question 29

Critical values of: Platelets

Answer 29

<20, 000/uL
>1 million/uL

Question 30

Critical values of: Prothrombin time

Answer 30

> 40 seconds