Heme Dry

A: Impedance occurs as the cells pass through the sensing aperture, causing voltage pulses that are measurable.

A: The number of pulses is proportional to the number of cells counted.

A: The height of the voltage pulse is directly proportional to the volume of the cell.

A: Pulses are collected and sorted (channelized) according to their amplitude by pulse height analyzers.

A: XN-CBC, XN-DIFF, XN-BF, nRBCs, RET-He (reticulocyte hemoglobin), and IRF (immature reticulocyte fraction).

A: The platelet analysis on the XN also uses a fluorescent count, in addition to the impedance count and optical count, called the PLT-F, performed by optical measurement.

A: A fluorocell fluorescent dye (oxazine) combined with an extended PLT counting volume and time.

A: Based on differences in intensity of the fluorescence combined with forward scattered light. PLT-F is performed on each specimen or as a reflex test based on laboratory PLT criteria.

A: The WBC, RBC, platelet counts, hemoglobin, and HCT are considered to be measured directly. Three hydraulic subsystems: WBC channel, RBC/platelet channel, and a separate hemoglobin channel.

A: In the WBC and RBC transducer chambers, diluted WBC and RBC samples are aspirated through the different apertures and counted using the impedance (DC detection) method for counting and volumetrically sizing cells.

A: Two unique features enhance the impedance technology: In the RBC/platelet channel, a sheathed stream with hydrodynamic focusing is used to direct cells through the aperture, which reduces coincident passage, particle volume distortion, and recirculation of blood cells around the aperture; and in the WBC and RBC/platelet channels, floating thresholds are used to discriminate each cell population.

A: Signals are transmitted in sequence to the analog circuit and particle volume distribution analysis circuits for conversion to cumulative cell volume distribution data. Particle volume distribution curves are constructed, and optimal position of the autodiscrimination level (i.e., threshold) is set by the microprocessor for each cell population.

A: The lower platelet threshold is automatically adjusted in the 2- to 6-fL volume range, and the upper threshold is adjusted in the 12- to 30-fL range, based on particle volume distribution.

A: RBC lower and upper thresholds may be set in the 25- to 75-fL and 200- to 250-fL volume ranges.

A: This floating threshold circuitry allows for discrimination of cell populations on a specimen-by-specimen basis. In the RBC channel, the floating discriminator is particularly useful in separating platelets from small RBCs.

A: From the RBC/platelet channel, based on the principle that the pulse height generated by the RBC is proportional to cell volume. The HCT is the RBC cumulative pulse height and is considered a true relative percentage volume of erythrocytes.

A: Hemoglobin is oxidized, binds to sodium lauryl sulfate (SLS), forms an SLS–hemoglobin complex, and is measured photometrically at 555 nm.

A: MCV, MCH, MCHC, RDW-SD, RDW-CV, MPV, and plateletcrit.

A: RDW-SD is the RBC arithmetic distribution width measured at 20% of the height of the RBC curve, reported in femtoliters, with a reference interval of 37 to 54 fL. RDW-CV is the RDW reported as a CV.

A: Plateletcrit is the platelet volume ratio, analogous to the HCT. MPV is calculated from the plateletcrit and platelet count just as erythrocyte MCV is calculated from the HCT and RBC count.

A: Platelet clumping, giant platelets, or cell fragments.

A: Four detection chambers to analyze WBCs and obtain a five-part differential: the DIFF, immature myeloid information (IMI), eosinophil (EO), and basophil (BASO) chambers. The high-end instrumentation such as the XE-series and the XN series has a six-part differential: neutrophils, lymphocytes, monocytes, eosinophils, basophils, and immature granulocytes. Every differential performed generates a percentage and absolute number for immature granulocytes, thus providing valuable information about the complete differential.

A: The XE series has the capability to run the platelet counting in the optical mode, which eliminates common interferences found with impedance counting. In the optical mode, the immature platelet fraction or IPF, can be measured to provide additional information concerning platelet kinetics in cases of thromobocytopenia.

A: Decreased and increased cellular hemoglobin content, using high-angle forward light scatter.

A: In the DIFF detection chamber, RBCs are hemolyzed and WBCs are analyzed simultaneously by low-frequency DC and high-frequency current (DC/RF detection method).

A: A scattergram of RF detection signals (y-axis) versus DC detection signals (x-axis) allows separation of the WBCs into lymphocytes, monocytes, and granulocytes. Floating discriminators determine the optimal separation between these populations.

A: Granulocytes are analyzed further in the IMI detection chamber to determine immature myeloid information. RBCs are lysed, and WBCs other than immature granulocytes are selectively shrunk by temperature and chemically controlled reactions. Analysis of the treated sample using the DC/RF detection method allows separation of immature cells on the IMI scattergram.

A: EOS and BASO are counted by impedance (DC detection) in separate chambers in which the RBCs are lysed, and WBCs other than eosinophils or basophils are selectively shrunk by temperature and chemically controlled reactions. Eosinophils and basophils are subtracted from the granulocyte count derived from the DIFF scattergram analysis to determine the neutrophil count.

A: Fluorescent flow cytometry.

A: In the WDF channel, RBCs are lysed, WBC membranes are perforated, and the DNA and RNA in the WBCs are stained with a fluorescent dye.

A: Enables separation and enumeration of neutrophils, eosinophils, lymphocytes, monocytes, and immature granulocytes.

A: In the WNR channel, the RBCs are lysed, including nucleated RBCs, and WBC membranes are perforated. A fluorescent polymethine dye, stains the nucleus and organelles of the WBCs with high fluorescence intensity and stains the released nuclei of the nucleated RBCs with low intensity.

A: Plotting side fluorescent light on the x-axis and forward scatter on the y-axis enables separation and enumeration of the total WBC count, basophils, and nucleated RBCs. The WBC count is automatically corrected when nucleated RBCs are present in the specimen.

A: WPC channel detects blasts and abnormal lymphocytes in a similar manner using a lysing agent and fluorescent dye and plotting side scatter on the x-axis and side fluorescent light on the y-axis.

PLT-F is a true fluroscent count, and the secondary method on the XN-series analyzers. Immature platelet fraction: IPF represents those immature platelets that have been recently released by the bone marrow.

A: PLT (PLT-F), IPF (Platelets, P License)
X-axis = Side fluorescence, separating based on size of nucleus
Y-axis = Forward scatter, seprated based on cell size

Immature Retic Fraction: The IRF is obtained as a ratio of reticulocytes count in the area with strong fluorescent light intesity in the RET scattergram (IRF zone), to the total reticulocyte count.
Reticulocyte Hemoglobin equivalent (RET-He): Measurement of the amount of hemoglobin in the immature red cells. It is unique to sysmex and it is derived using the reticulocyte scattered light signals and a proprietary sysmex calculation.

A: RET%, RET#, IRF, RET-He (Reticulocytes, R License)
X-axis = side fluorescence, separating based on size of nucleus
Y-axis = forward, separting based on cell size

Provides improved differentiation of blast cell and abnormal lymphocyte flagging. Abnormal lymphocytes: Lysercell WPC reagent effeciently perforates the cell membrane of abnormal lymphocytes, allowing Fluorocell WPC reagent to effectively stain the cell nuclei, resulting in higher side fluorescence in the flow cell. Blasts are not effectively perforated by the Lysercell reagent which leads to a lower side fluorescence.

leads to falsely low RBC, Hgb and falsely high MCV, MCH, MCHC

falsely elevated Hgb, MCH, and MCHC

A: The rate of RBC settle is measured as the number of millimeters of clear plasma present at the top of the column after one hour (mm/hr).

A: RBCs settle because their density is greater than that of plasma.

A: An alteration in the distribution of charges on the surface of RBCs results in the formation of aggregates known as rouleaux.

A: Increased levels of plasma fibrinogen and globulins.

A: ESR reflects changes in plasma proteins that accompany acute and chronic infections, some tumors, and degenerative diseases.

A: ESR is a non-specific screening test.

1. Negative charge on the RBC by zeta potential, if this charge is neutralized, rouleaux formation occurs
2. RBC rate fall through plasma
3. Packing of RBC
4. The distance is measured in mm/hr, after 1 hour

A: Inflammation causes the cells to clump together.

A: Clumps have a higher density than individual cells and therefore tend to settle at the bottom more rapidly.

A: ESR measures the rate at which RBCs separate from the plasma and fall to the bottom of the tube.

A: Higher values mean greater inflammation.

A: Certain medications and drugs can affect a person’s ESR test result.

A. Because they are susceptible to a variety of factors such as, temperature, hematocrit, erythrocyte mean corpuscular volume (MCV), and plasma viscosity.

A.
- Fibrinogen
- Globulins (alpha 1 and alpha 2)
- Technical factors such as mechanical vibrations
- Elevated room temperature.

A.
- Abnormally shaped RBC (sickle, spherocytosis)
- Hemolysis
- Clotted sample
- Presence of air bubble
- Low room temperature
- Delay in test performance
- Excess anticoagulant
- Specimen quality such as blood to anticoagulant ratio, age of specimen and fill volume

A: Westergren and Wintrobe. Both methods require manual pipetting, special materials, and long analysis times.

A: The iSED/iSED ELITE Automated Erythrocyte Sedimentation Rate Analyzer.

A: Uses advanced photometric rheology technology to measure the rouleaux formation, the earliest form of erythrocyte sedimentation

A. The aggregation of RBCs during the rouleaux formation ultimately determines the length at which the red cells sediment in the Westergren tube.

A. The iSeds analyzer consists of “directly” measuring the aggregation of the RBCs, while traditional ESR methods “indirectly” measure aggregation of the RBCs by recording the length at which the red cells setting in a Westergren tube.

A: It captures the critical kinetics of RBC aggregation in the testing environment, helping reduce the impact of factors that contribute to result variability.

A: The sample is automatically mixed in position.

A: A sensitive optical detector monitors light transmission through the sample over time.This produces a signal that is direct representation of the aggregation.

A. The analyzer directly uses primary EDTA blood collection tube and produces ESR results within 20 seconds. Results are reported in mm/hr and iSed/iSed ELITE performance is highly correlated with the Westergren method.

A. An unclotted sample in a EDTA tube. A CBC includes RBC, WBC, HGB, HCT, PLT, MCV, MCH and MCHC.

A. Ranges: Male 4.5-6.0 x 10^12/L, Female 4.5-5.1 x 10^12/L

A. Ranges: 4.5-11 x 10^3/microL

A.
- Number of Total WBC can indicate infection
- High sub population can indicate type of infection
- Abnormal proliferation can indicate cancer

A. Range: 150-450 x 10^9 /L
Platelets are involved in clotting

A. Ranges:
Male 14-17.5 g/dL
Female 12.3-15.3 g/dL

A. Responsible for oxygen carrying capacity. If there is a mutation, it affects oxygen carrying capacity and can increase number of RBCs

A. Ranges:
Male 41.5-50%
Female 35.9-44.6%

A.
- MCV is Average “size” of rbc
- HCT x 10/RBC
- Range 80-96 fL
- Indicates: Microcytes, Normocytes, Macrocytes

A.
- Average amount of hgb per rbc
- HGB X 10/ RBC
- Range: 27-33 pg
- Indicates: Hypochromic, Hyperchromic

A.
- Average hgb in a given volume of rbc volume
- MCH/MCV x 100
- Range: 33-36 g/dL
- If high, suspect agglutination

Normocytic, Normochromic

Microcytic, Hypochromic

Macroovalocytes

Spherocytes, Hyperchromic

A:
- Indicates variation of RBC size
- Range 11.5%-14.5%

A.
- Check for to verify indices
- Look for clots
- Estimate platelets
- Look for “weird” rbcs and wbcs
- 100 WBC differential

A: If a patient has Anemia, Infection, Leukemia & Clotting

A:

A: WBCs help fight infection, therefore, elevated WBC count suggests infection.

A:
- WBCC = WBC Count
- Instrument sorts into 5 types of cells
- By percentage = relative
- Percentage x WBCC = Absolute

A: Neutrophils are the most common white blood cell, making up an average of 56% of WBCs (range 33–71%), and they are elevated in bacterial infections.

A: Lymphocytes get bigger as it "reacts", are activated against viruses and make up an average of 34% of WBCs.

A: Monocytes are the largest leukocytes, they are phagocytic cells and make up an average of 2 to 10% of WBCs.

A: Eosinophils have a characteristic pink granules, are elevated in allergies and worm infections and make up 3% of WBCs.

A: Basophils are the smallest % of WBC (0.6%) and an increase of basos may indicate CML.

Reticulocyte/nRBC - Immature RBCs

Leukemia (AML)

Leukemia (CML)

Left shift

Malaria (RBC parasites)

Answer: B (rule of 3)

A:

A: Most of blood (~55%) is plasma or serum. Then, there is a layer of white blood cells or leukocytes. (~1%). Red blood cells or erythrocytes make up ~44% of blood.

A:
- Small, measuring around 7 um in diameter and 2 um thick
- Biconcave disc shape makes them flexible and can squeeze through small spaces such as capillaries
- Lose their nucleus when they mature, before it leaves the bone marrow
- Typically lives ~120 days
- A typical human has 5-6 liters of blood

A: The property of the circulation that maintains blood as a fluid within the blood vessels, and the systems ability to form a barrier(blood clot) to prevent excessive blood loss when the vessel is damaged.

A: a term describing the formation and development of blood cells.

A: Loss, destruction and Self Renewal. This system involves: Proliferation, Differentiation and Maturation.

A: Hematopoiesis begins as early as the nineteenth day after fertilization in the yolk sac of the embryo. Only erythrocytes are made which contain unique fetal hemoglobin.

A: Yolk sac production of erythrocytes decreases and production of RBCs in the human embryo itself begins.

A:
- The fetal liver then becomes the chief site of blood cell production.
- Erythrocytes and the beginnings of WBC and Platelets occurs
- The spleen, kidney, thymus, and lymph nodes serve as minor sites of blood cell production.

A: BM is primary site after ~ 6 months and leukocytes and thrombocyte production increases when BM switch.

A: Hematopoiesis in the bone marrow is called medullary hematopoiesis. Hematopoiesis in areas other then the bone marrow is called extramedullary hematopoiesis.

A: Bone marrow is located inside spongy bone. In a normal adult, half of the BM is hematopoietically active (red marrow) and half is inactive, fatty marrow (yellow marrow).

A: Red marrow contains erythroid, leukocyte, and platelet precursors. Early in life most marrow is red marrow, but it gradually decreases with age to 50% in adults.

A: It can increase its activity to 5–10 times its normal rate.

A: It occurs in conditions with increased or ineffective hematopoiesis.

A:
- Acute blood loss: temporary replacement of yellow marrow.
- Severe chronic anemia: marrow may erode the bone itself.
- Malignant disease: both normal red marrow and fatty marrow may be replaced by proliferating abnormal cells.

A: The hematopoietic tissue may become inactive or hypoplastic.

A:
- Chemicals
- Genetics
- Myeloproliferative disease that replaces hematopoietic tissue with fibrous tissue

A: Hematopoietic cells can be divided into three cellular compartments: pluripotential stem cells, committed progenitor stem cells, and mature cells.

A: They are capable of self-renewal and differentiation into all blood cell lines.

A: Stem cells destined to develop into distinct cell lines.

A: They are mature cells with specialized functions.

A: The mononuclear phagocytic system is involved in cellular destruction

A:
- Circulating blood monocytes
- Fixed macrophages in the bone marrow, liver, spleen, and lymph nodes
- Free macrophages

A: The spleen contains the largest collection of lymphocytes and mononuclear phagocytes in the body.

A:
- Filtering and destruction
- Removal of particles (pitting)
- Enforcing close contact of blood-borne antigens with lymphocytes and phagocytic cells

A: It may lead to hypersplenism, an overactive spleen that removes blood cells too early and too quickly.

A: Splenomegaly

A: Primary splenomegaly has no identified underlying disease, while secondary splenomegaly is caused by an underlying disorder.

A: Inflammatory diseases, infectious diseases, compensatory or workload hypertrophy (abnormal RBCs (spherocytes), and antibody-coated RBCs (ITP)).

A: By splenectomy.

A: Lymph nodes, lymphatic vessels, and lymph.

A: Lymph nodes are composed of lymphocytes, macrophages, and a reticular network. As antigens pass through, they encounter and stimulate immunocompetent lymphocytes to proliferate and differentiate into effector cells.

A: Lymph is a thin watery fluid formed from plasma when it diffuses into tissue spaces.

A: It serves as a compartment for the maturation of T lymphocytes into immunocompetent T cells.

A: Thymosin

A: Phagocytes known as Kupffer cells, which act as a filter for damaged or aged cells, though less efficiently than the phagocytic cells in the spleen.

A: It is capable of extramedullary hematopoiesis.

A: Mature blood cells have a limited lifespan and, except for lymphocytes. Mature lymphocytes are incapable of self-renewal.

A: pluripotential stem cells in the bone marrow.