Histograms

Coulter principle

cells are poor conductors of electricity cause voltage drops in electrical field

Why do neutrophils appear bigger on optical cell counters

Neutrophils have more granules in the cytoplasm having more reflections

Also, during dilution the neutrophils will actually expand due to the additive while nongranulocytes will shrink

Fluorochromes

molecules that emit fluorescence upon excitation. Some are proteins some are small organic compounds

Flow cytometry

combines optical cell counting with specific markers. Using laser optics

Fluorochromes help with what

Cell population to be analyzed. Different cell populations emit light at different wavelengths

MPV=Mean platelet volume

As platelet count increases the MPV decreases

When platelets break off metamegakaryocyte it may be larger (4u) then into smaller fragments as it matures

Anisocytosis

abnormal MCV

Increased RDW

variation in size

Macrocytes- with normal RDW

Increased MCV, normal RDW

population of large, macrocytic cells

Macryocytes-increased RDW

increased MCV and increased RDW

large cells, lots of variation

Two peaks

Two RBC populations

One peak has low MCV

one has normal MCV

lots of variation in size=RDW

Microcytic anemia

Two RBC populations

MCV=low, small so microcytic cells

RDW is larger

WBC fragments

WBC may be fragmented in patients receiving chemotherapy

instrument count fragments as platelets

manual count required

Nucleated RBCs

Nucleated RBC will fall within the same size range of lymphs

Two peaks on histograms which tells us something is wrong

What does a wide histogram for MCV mean

a wide range of RBC size, multiple cell populations

What would a second bump at the 150 mark mean

Reticulocytes and/or WBC being counted. Usually follows with lower RBC count

Why would a bleed cause a high MPV

Because more blood is leaving so more immature platelets (or any cell really) would be released to replace the bleed so a wide range of size

Explain why it looks like there are more lymphs than monocytes (mononuclear cells)

Monocytes have more variety of size while lymphs are more uniform. If the monocytes were stacked up instead of horizontal it would be more monocytes than lymphs

Anisocytosis

normal and abnormal MCV increased RDW

variation in size

Macrocytes

Increase MCV

normal RDW

increased MCV, normal RDW

shifted to the right, population of large, macrocytic cells

megaloblastic anemia

B-12 deficiency or folate deficiency or intrinsic factor deficiency

increased lobes and large cell

macrocytes

increased MCV

(possible) Increased RDW

large cells, lots of variation

Two peaks

MCV of both

RDW

two RBC population

One has low MCV, one has normal MCV

RDW-lots of variation

Microcytic anemia

MCV 63.8 fl

RDW 36.5%

The tall peak is microcytic small peak is transfused RBC

very low MCV

RDW is larger than it should be

Microcytic anemia post iron treatment

no more double peakes

microcytic RBC

from the microcytic RBC side: fragmentation can occur that overlap with platelets

From platelets: large platelets can over lap with RBC.

microcytic or fragmented RBCs

MCV 63 fl

RDW 36.5%

Fragments contaminate platelet count causing the rise at the end

WBC fragments

may be fragmented in patients receiving chemotherapy, may be counted as platelets, manual platelet count required

What can cause abnormal WBC histograms

nucleated RBC-will fall within the same size range. Two peaks