The percentage formula of white blood cells (peripheral blood smear) – when to perform the test, interpretation of the results, price

Proven content

A peripheral blood smear gives you precise information about the number of different types of leukocyte cells in your blood. There are several types of cells in the plasma that belong to the white blood cell system. Another indication for the performance of the percentage formula is the suspicion of bacterial, fungal or viral infections.

What is the percentage formula for white blood cells?

A peripheral blood smear is a detailed analysis of individual blood cells, more precisely their number and structure. A manual smear is a microscopic examination of red and white blood cells and platelets. This study also allows for percentage of the composition of white blood cells, thanks to which we obtain the percentage formula of white blood cells. During the study, at least five populations of leukocytes are analyzed: monocytes, basophils, lymphocytes, neutrophils, eosinophils. Sometimes the total number of white blood cells is normal, but there may be a deficiency or excess of cells from individual lines.

Leukocytes include the cells of the granulocytic system along with monocytes, and cells of the lymphocytic system. It is worth emphasizing that the peripheral blood smear does not burden the patient in any way, because an adult, healthy person can donate up to 500 ml of blood, and about 30 ml are collected for the test. Moreover, the study is relatively cheap and gives us a lot of information about our health.

If we do complete blood count with smear, we will obtain detailed results, including the parameters of platelets (PLT, MPV, P-LCR, PDV) and red blood cells (including RBC, MCV, RDW, RET).

Also read:

1. Blood morphology – what is this test, what are the standards?
2. How to read the morphology results?
3. Life-saving research – blood tests

When do we do a peripheral blood smear?

Peripheral blood smear microscopy is not normally performed as part of normal blood counts. Most often, extended tests are prescribed by a doctor when he observes abnormalities in the morphology or it is necessary to carefully monitor the patient’s condition.

The most common indications for a peripheral blood test are listed below:

1. Obtaining unsatisfactory morphology results.
2. Malaise, fatigue, weakness, especially when combined with abnormalities in standard morphology.
3. Bleeding, problems with clotting.
4. In the diagnosis of various diseases, including anemia, diseases related to the incorrect production of blood counts, fungal and bacterial infections (typhoid, tuberculosis, sepsis), viral (measles, rubella) and cancer.
5. To monitor patients undergoing treatment with chemotherapy, radiotherapy, steroids or certain medications for chronic diseases (if your doctor recommends it).
6. Suspicion or treatment of systemic connective tissue diseases (collagen diseases).

Peripheral blood smear – preparation for the examination

General patient recommendations for donating a peripheral blood sample for testing are not restrictive. Blood collection can be performed at any time of the day, however, if the tests are repeated, it is recommended to perform the test at a similar time.

In order to avoid irregularities and obtain a true-to-life formula for the percentage of white blood cells, it is worth remembering that the result may be influenced by:

1. previously eaten meal – therefore it is recommended to make a smear on an empty stomach;
2. physical activity;
3. severe stress;
4. some medications – inform the doctor who ordered the examination about the recently taken medications or medications for chronic diseases.

Before taking blood for the test, it is recommended to drink a glass of water, and also to rest and relax in the waiting room.

The percentage formula of white blood cells – the course of the study

Peripheral blood smear material: full blood.

Preparation for the test: on an empty stomach (at least 8 hours).

The course of a peripheral blood smear: one-time blood sampling from a vein in the arm. The obtained sample is sent for further laboratory analysis.

Time to wait for the result: 1 Day.

When assessing red blood cells, attention is paid to such elements as: color, shape, size, the presence of parasites and the presence of intracellular disgust. The result of a peripheral blood smear is considered normal when all the analyzed parameters do not exceed the normal limits, which are usually constant and independent of external factors (although they may differ in individual laboratories).

Norms (in adults):

1. rod-like granulocytes: 3-5%,
2. segmented granulocytes: 57–65%,
3. neutrophils: 45-70%,
4. eozynofile: 1-5%,
5. basophils: 0-3%,
6. lymphocytes: 15-40%,
7. monocytes: 2-8%.

The percentage formula of white blood cells – interpretation of the results

Do not interpret the results of a peripheral blood smear on your own. This is the task of the doctor who ordered the test. He takes into account all factors that may have influenced the result, as well as ordering further tests or issuing a referral to another specialist.

Possible causes of deviations from the norm in the percentage formula of white blood cells are:

1.An increased number of eosinophils indicates:

1. acute lymphoblastic leukemia,
2. allergies,
3. parasitic infections.

2. An increased number of basophils (basophils) occurs in the course of:

1. myeloid leukemia,
2. polycythemia vera.

3. Excessive amount of neutrophils (neutrophils) may be due to:

1. rheumatoid arthritis,
2. bacterial infection,
3. myeloid leukemia,
4. the use of glucocorticosteroids.

4. The decreased number of neutrophils in the peripheral blood smear is the result of:

1. viral infections,
2. chemotherapy,
3. radiation therapy.

5. We observe an increased number of monocytes in the course of:

1. szpiczaka manygiego,
2. syphilis
3. typhoid fever,
4. brucellosis,
5. tumors,
6. surgical injuries,
7. infections: parasitic, viral, bacterial,
8. leukemia
9. RA,
10. tuberculosis,
11. terapii glikokortykosteroidami,
12. systemic connective tissue disease.

6. Lowered lymphocyte concentration it is the result of chemotherapy and radiotherapy, but also of taking: corticosteroids with anti-inflammatory and anti-allergic properties. Severe viral infections may also be the cause of lymphocyte decline.

7. An increased number of lymphocytes may occur when:

1. lymphocytic leukemia,
2. lymphoma,
3. whooping cough
4. syphilis
5. viral and bacterial infections,
6. viral hepatitis,
7. measles
8. pigs,
9. rubella,
10. szpiczaka manygiego.

Peripheral blood smear – price of the test

In the case of taking a peripheral blood smear, we will pay privately for the test from 6 to 20 PLN. The prices depend on the laboratory where we decide to perform the test. If we have a referral from a doctor who admitted us for an appointment under the National Health Fund, the examination will be free of charge.