Reasons for the shift of the leukocyte blood formula

Diseases and conditions accompanied by a shift in the leukocyte formula

Shift left (metamyelocytes, myelocytes)	Shift to the left with rejuvenation (in the blood there are metamyelocytes, myelocytes, promyelocytes, myeloblasts and erythroblasts)	Shift to the right (decrease in the number of stab neutrophils in combination with the presence of hypersegmented neutrophil nuclei)
Acute inflammatory processes Purulent infections Acute bleeding Acidosis and coma states Physical overstrain	Chronic leukemia Erythroleukemia Myelofibrosis Metastases of tumors Acute leukemia Comatose conditions	Megaloblastic anemia Kidney and liver diseases Conditions after a blood transfusion

With many severe infections, septic and purulent processes, the leukocyte formula changes due to an increase in the number of stab neutrophils, metamyelocytes and myelocytes. Such a change in the leukogram with an increase in the percentage of young forms of neutrophils is called the left shift; The increase is mainly due to segment-nuclear and polysegment-nucleus forms - a shift to the right. Severity of neutrophil nuclear shift is estimated by the shift index (IC).

IS = (M + MM + P) / C,

Where M - myelocytes, MM - metamyelocytes, P - stab neutrophils, C - segmented neutrophils. The reference value of the IC is 0.06. The value of IP is an important criterion determining the severity of acute infection and a general prognosis.

When analyzing the results of calculating the leukocyte formula in a blood smear, it should always be remembered that this method is not very accurate and can be a source of errors that can not be completely eliminated (including errors in blood sampling, preparation and staining of the smear, human subjectivity in the interpretation of cells). Some types of cells, especially monocytes, eosinophils and basophils, are distributed in a smear completely illegally. The high content of these cells, especially in the restricted area of the smear, must be rechecked before the result is issued. When the number of leukocytes in the blood is more than 35 × 10 ⁹ / l, it is recommended to count at least 200 cells for greater accuracy. The number of leukocytes examined should increase in proportion to the increase in leukocytosis in order to assess the large area of the smear. If the number of leukocytes in the blood is less than 2 × 10 ⁹ / l, then some laboratories count less than 100 cells. However, the accuracy is sharply reduced, so this calculation is not recommended. If you can not find 100 cells in the smear, it is suggested to do leuco concentrate, but remember that during the preparation of the latter there are morphological changes in leukocytes and uneven distribution of cell types. If less than 100 or more than 100 cells were counted, this should be reflected in the result form.

95% confidence interval when calculating leukoformula in a blood smear

Content of a certain cell type,%	Total counted cells
	100	200	500	1000
0	0-4	0-2	0-1	0-1
1	0-6	0-4	0-3	0-2
2	0-8	0-6	0-4	1-4
3	0-9	1-7	1-5	2-5
4	1-10	1-8	2-7	2-6
5	1-12	2-10	3-8	3-7
6th	2-13	3-11	4-9	4-8
7th	2-14	3-12	4-10	5-9
8	3-16	4-13	5-11	6-10
9	4-17	5-14	6-12	7-11
10	4-18	6-16	7-13	8-13
15	8-24	10-21	11-19	12-18
20	12-30	14-27	16-24	17-23
25	16-35	19-32	21-30	22-28
Thirty	21-40	23-37	26-35	27-33
35	25-46	28-43	30-40	32-39
40	30-51	33-48	35-45	36-44
45	35-56	38-53	40-50	41-49
50	39-61	42-58	45-55	46-54

Widely spread to assess the severity of endogenous intoxication received a leukocyte intoxication index (LII), the reference value of which is approximately 1.0. The formula for the calculation is as follows.

LII = [4 (myelocytes) + 3 (metamyelocytes) + 2 (stab neutrophils) + (segmentonuclear) × (plasmocytes + 1)] / [(lymphocytes + monocytes) × (eosinophils + 1)]

Fluctuations LII in patients with infectious and septic diseases objectively correspond to changes in the clinical picture and the degree of expression of endogenous intoxication. The increase in LII to 4-9 indicates a significant bacterial component of endogenous intoxication, a moderate increase (up to 2-3) - either limiting the infectious process or the focus of necrobiotic tissue changes. Leukopenia with high FII is an alarming prognostic sign. LII can be used to assess the effectiveness of the treatment.

[1], [2], [3], [4], [5]