Pro6.4-B-09



Peripheral Smear Grading of RBC, WBC and Platelets for Manual Differentials Guideline

|Subject |Guideline Number |Pro64-B-09-G |

|Peripheral Smear Grading of RBC, WBC and Platelets for Manual | | |

|Differentials Guidelines | | |

| |Effective Date |12 June 2008 |

|Author |Page |1 of 4 |

|Heidi Hanes | | |

|International QA/QC Coordinator | | |

| |Supersedes |New |

|Review by |Amy Rada |Review date |04 May 2020 |

|pSMILE Comments: This document is provided as an example only. It must be revised to accurately reflect your lab’s specific processes and/or specific |

|protocol requirements. Users are encouraged to ensure compliance with local laws and study protocol policies when considering the application of this |

|document. If you have any questions contact your SMILE representative. |

The guideline below can be used for grading RBC morphology and inclusions, WBC estimates and inclusions and Platelet estimates. For RBC grading use 100x oil immersion lens.

RBC Morphology

Anisocytosis:

Count the macrocytic and/or microcytic RBC separately in 10 fields of evenly dispersed RBCs. Divide the total of these fields by 10 to establish the mean. Add both for total and use the table below for grading.

|NORMAL |Slight ANISO |Moderate ANISO |Marked ANISO |

| 0-5 | 6-15 | 15-30 | >30 |

Polychromasia:

Count the polychromatophilic (gray-blue) RBC in 10 fields containing evenly dispersed RBCs. Divide the total of these fields by 10 to establish mean. Use the table below for grading.

| NORMAL | Slight POLY | Moderate POLY |Marked POLY |

| 0-2 | 3-4 | 5-6 | >6 |

Poikilocytosis:

Note the number of abnormal shapes in 10 fields of evenly dispersed RBCs. Divide the total of these fields by 10 to establish the mean. Use the table below for grading.

| SLIGHT | MODERATE | MARKED |

| 1-2 | 3-4 | >5 |

NOTE: Cannot call poikilocytosis unless abnormal shapes are noted such as schistocytes, burr cells, sickle cell forms, etc.

Types of Poikilocytosis:

Each abnormal RBC shape must be evaluated SEPARATELY .

Count the number of a particular abnormal shape in 10 fields and divide total by 10 for mean. Use the table below as a guideline.

|Abn Shape | Normal | Occasional/Few | Moderate | Numerous/ Many |

|Spherocyte | 0 | 1-5 | 6-15 | >15 |

|Acanthocyte | 0 | 1-5 | 6-15 | >15 |

|Sickle Cell | 0 | 1-5 | 6-15 | >15 |

|Tear Drop | 0-1 | 2-5 | 6-15 | >15 |

|Target Cell | 0-1 | 2-5 | 6-15 | >15 |

|Schistocyte | 0-1 | 2-5 | 6-15 | >15 |

|Ovalocyte | 0-1 | 2-5 | 6-15 | >15 |

|Burr Cell | 0-1 | 2-5 | 6-15 | >15 |

|Stomatocyte | 0-1 | 2-5 | 6-15 | >15 |

RBC Inclusions:

Repeat procedure for each type of RBC inclusion on smear as for poikilocytosis and use the table below for guideline.

|Inclusion | Normal | Occasional/Few | Moderate | Numerous/ Many |

|Howell-Jolly | none | 1-2 | 3-5 | >5 |

|Pappenheimer Body | none | 1-2 | 3-5 | >5 |

|Basophilic Stippling | none | 1-2 | 3-5 | >5 |

Alternative grading:

|1+ |2+ |3+ |4+ |

|1-6 per field |7-10 per field |11-20 per field |>20 per field |

WBC Estimates

Total WBC estimate on blood smear.

|Step |Action |

|1 |Use 40x lens on microscope to do the estimate |

|2 |In the feathered-edge where there is no overlap of Red Blood cells count the number of White Blood cells seen |

| |in 10 fields. |

|3 |Divide the total counted by 10 to get the average number per field. |

|4 |Multiple average per field by 3000 to get estimate. |

The instrument and manual White Blood Count estimate should be compared to insure

they agree within+/-20% of each other. If there is no agreement the WBC should be re-

checked by back-up method. This method is less reliable when the automate leukocytes

count/cumm is greater than 25,000.

Alternative Objectives Estimates

|If |Then |

|Using 20X objective |Divide average number per field by 4 and multiply by 1000 for final estimate. |

|Using 10X objective |Divide average number per field by 8 and multiply by 1000 for final estimate. |

The following table can be used to report out WBC estimate only results.

|Decreased |< 4500/mm3 |

|Low Normal | 4500-6,000/mm3 |

|Normal | 4500-10,500/mm3 |

|High Normal | 8500-10,500/mm3 |

|Increased |> 10,500/mm3 |

NOTE: Ranges are depended on patient population, adjusted as needed.

The following White Blood Cell inclusions or changes should be noted:

Each abnormal WBC inclusion must be evaluated SEPARATELY.

Count the number of a particular inclusion in 10 fields and divide total by 10 for mean. Use the table below as a guideline.

|Inclusion | Normal | Occasional/Few | Moderate | Numerous/ Many |

|Dohle Bodies |none | 1-2 | 3-5 | >5 |

|Toxic Granulation |none | 1-2 | 3-5 | >5 |

|Hypersegmentation |none | 1-2 | 3-5 | >5 |

|Smudge Cells |none | 1-2 | 3-5 | >5 |

|Vacuolated Neutrophils |none | 1-2 | 3-5 | >5 |

Platelet Estimates

Platelet estimation should agrees with instrument (or manual) count. Use procedure below

to estimate platelet count.

|Step |Action |

|1 |Under 100x oil immersion check feather edge and sides to check for any clumping of platelets. |

| |If |

| |Then |

| | |

| |Clumping is observed |

| |Instrument results may be questionable. |

| | |

| | |

| |Numerical result |

| |Redrawing of sample is recommended and retesting. |

| | |

| | |

| |Redraw not possible |

| |Only platelet estimate can be reported with clumped sample. |

| | |

| |No clumping |

| |Perform platelet estimate as described below. |

| | |

|2 |Platelet estimate is performed on the slide in the area adjoining but not in the feather edge of the stained |

| |slide. |

|3 |Enumerate the total number of platelets in 10 oil immersion fields. |

|4 |Divide total number of platelets counted by 10 to get the mean per field. |

|5 |Multiple the mean by 15,000 and this should be approximately the instrument count. |

Instrument and manual Platelet estimate should be compared to insure they agree within

+/-20% each other. If there is no agreement the Platelets should be re-checked by back-up

method. Note: Some references prefer to multiply by 20,000 instead of 15,000. Please

use the one that best fits your laboratory.

References:

A color Atlas and Instruction manual of Peripheral blood Cell Morphology, by Barbara H

O’Connor, M.S., S.H. (ASCP), Lippincott Williams and Wilkins, 351 West Camden St.

Baltimore, MD 21201, 1984.

University of Mississippi Medical Center, Hematology: Normal Differentials/ RBC

Morphology, Class 312/322

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