Questions to Review

Xerocytes

are dehydrated red cells and have a dark side with concentrated hemoglobin and a lighter side with less hemoglobin. Xerocytes are seen in a genetic disease, hereditary xerocytosis. The red cells in this disorder are unable to regulate the flow of cations in the cell, resulting in dehydration of the cell.

Whole blood if composed of approximately:

45% formed elements and 55% plasma Whole blood is composed of 45% formed elements and 55% plasma. This is helpful information, especially when blood is collected, as about half of the volume of blood drawn will be serum or plasm

All of the following CD markers are present on a normal mature T cell, EXCEPT? CD20 CD7 CD3 CD5

CD20 The CD20 marker is NOT present on mature T cells. CD20 is expressed by B cells. Normal mature T cells should express CD2, CD3, CD5 and CD7 markers.

Which of the following cells is the most common nucleated cell in normal adult bone marrow?

Myeloblast Promyelocyte Myelocyte Metamyelocyte Of the given choices, metamyelocytes are the most abundant form seen in a normal bone marrow. Reference interval is 3-20% Myeloblast reference interval is 0-3%. Promyelocyte reference interval is 1-5%. Myelocyte reference interval is 6-17%.

What is the normal myeloid to erythroid (M:E) ratio in the bone marrow?

2:1 - 4:1 In the bone marrow, the ratio of myeloid cells to erythroid cells ranges from 2:1 to 4:1 in healthy individuals (when segmented neutrophils are included in the myeloid count). If segmented neutrophils are not included in the count, the M:E reference range is between 1.5:1 to 3:1.

Basophils' primary role involves:

Allergic reactions Basophils have a membrane receptor for IgE. When IgE attaches to this receptor, it causes the basophil to become activated and degranulate. As degranulation occurs, basophils release a series of granular components that orchestrate the allergic reaction. Neutrophils and macrophages are capable of phagocytosis, while lymphocytes are responsible for long-term immunity and eosinophils are capable of fighting helminth parasites.

(Dont know) Which of these blood levels will decrease during intravascular hemolysis? Serum (plasma) LDH Serum (plasma) bilirubin Reticulocytes Haptoglobin

Haptoglobin Haptoglobin is an alpha2-globulin that binds to free hemoglobin intravascularly. The large haptoglobin-hemoglobin complex cannot be filtered by the kidneys. The complex travels to the liver where hepatocytes will process the hemoglobin in a mechanism similar to the extravascular destruction mechanism. Increased intravascular destruction of red blood cells will result in a decrease in the haptoglobin level. Intravascular hemolysis is typically associated with increased levels of serum (plasma) LDH and bilirubin, and an increased number of reticulocytes. Serum LDH is found in higher levels during intravascular hemolysis due to fact that high levels of LDH are normally found within the red cells but is now being spilled into the bloodstream via red cell lysis. Bilirubin is a breakdown product of hemoglobin, which has also been spilled into the bloodstream from broken red blood cells via hemolysis. Reticulocytosis is a reflection of the release of an increased number of immature red blood cells from the marrow to account for the red blood cells that are lost through hemolysis. This is a normal response. Failure to show an increased reticulocyte count with hemolytic episodes or hemorrhage would indicate ineffective erythropoiesis (possible bone marrow function problem).

Pluripotential stem cells are capable of producing which of the following?

Lymphoid and myeloid stem cells Pluripotential stem cells have the potential to self-renew, proliferate, and are ultimately capable of differentiating into all cell lines, including: erythrocytic, myeloid, lymphoid, and megakaryocytic cell lines.

What is platelet satellitosis?

Platelets encircling neutrophils is a phenomenon referred to as platelet satellitosis. This "pseudothrombocytopenia" occurs when the blood of some individuals is anticoagulated with EDTA. Recollecting the specimen using sodium citrate often corrects this problem. If sodium citrate is used, the platelet count obtained must be multiplied by 1.1 for reporting purposes. Multiplying by 1.1 adds back the 10% loss of platelets seen when sodium citrate, with a 9:1 ratio of blood to anticoagulant, is used.

What RBC morphology on a Wright-stained smear may indicate the presence of an unstable hemoglobin?

Schistocytes; Though not diagnostic for alpha thalassemia, schistocytes (fragmented RBCs) indicate that there is one of several forms of red blood cell destruction occurs. When unstable hemoglobin is formed, such as Hemoglobin H in alpha thalassemia intermedia, macrophages may remove the precipitated tetramers out of the cell, leaving it appearing "bitten." These "bite" cells are schistocytes.

Codocytes

or target cells, have hemoglobin concentrated in the center and the periphery of the red cell, forming a target shape. Codocytes are seen in thalassemia and many hemoglobinopathies, such as Hemoglobin C disease.

Acanthocytes

sometimes called spur cells, have a few membrane projections of different sizes. Acanthocytes may be seen in acute liver disease.